4.0.0 Release 🚀

We will update the required Java version at some point, the only question is when.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,31 +0,0 @@
----
-name: Bug report
-about: Create a bug report so we can fix it
-
----
-
-**Describe the bug, provide any errors**
-A clear and concise description of what the bug is. If present, can you paste the error to https://paste.gg/?
-
-**How can we reproduce it?**
-Steps to reproduce the behavior:
-1. Login on 1.12'
-2. Click on '....'
-3. The '....' is displayed wrong
-
-**Expected behaviour**
-A clear and concise description of what you expected to happen.
-
-**Screenshots**
-If applicable, add screenshots to help explain your problem.
-
-**ViaVersion Dump**
-- Type /viaversion dump, and put the link here.
-
-**Additional server info**
-Do you use a proxy (eg. BungeeCord)? What software do you use and what plugins?
-
-**Checklist**
-- [ ] I have included a Viaversion dump
-- [ ] If applicable, I have included a paste (not a screenshot) of the error
-- [ ] I have tried a build from https://ci.viaversion.com/ and the issue still persists

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,91 @@
+name: Bug Report
+description: Report a bug or console error
+
+body:
+  - type: markdown
+    attributes:
+      value: |
+        **Before reporting a bug, please see if using master/dev builds from https://ci.viaversion.com/ fixes your issue.**
+        Whenever you see fit, you can upload images or video to any of the textfields.
+
+  - type: input
+    attributes:
+      label: "`/viaversion dump` Output"
+      description: |
+        Run `/viaversion dump` in the console or in the chat, then copy and paste the given link here.
+      placeholder: |
+        https://dump.viaversion.com/...
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Console Error
+      description: |
+        If you encounter warnings/errors in your console, **paste them with https://paste.gg/ and put the paste link here**.
+        If the error is small/less than 10 lines, you may put it directly into this field.
+      value: |
+        ```
+        Put the paste.gg link or text here.
+        ```
+      placeholder: Please do not remove the grave accents; simply replace the line of text in the middle.
+    validations:
+      required: false
+
+  - type: textarea
+    attributes:
+      label: Bug Description
+      description: |
+        Describe the unexpected behavior.
+        If you want to attach screenshots, use the comment field at the bottom of the page.
+      placeholder: |
+        Example: "Placing signs on 1.13.2 causes text to disappear."
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Steps to Reproduce
+      description: |
+        List the steps on how we can reproduce the issue. Make sure we can easily understand what you mean with each step.
+      placeholder: |
+        Example:
+        1. Login with a 1.13.2 client
+        2. Place a sign
+        3. The sign text is displayed wrong
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Expected Behavior
+      description: |
+        Describe what exactly you expected to happen.
+      placeholder: |
+        Example: "Placed sign text should not disappear."
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Additional Server Info
+      description: |
+        Do you use a proxy (eg. BungeeCord)? What software do you use and what plugins?
+      placeholder: |
+        Example: "I also use BungeeCord with the following plugins: x, y, z"
+    validations:
+      required: false
+
+  - type: checkboxes
+    attributes:
+      label: Checklist
+      description: Make sure you have followed each of the steps outlined here.
+      options:
+        - label: Via plugins are only running on **EITHER** the backend servers (e.g. Paper) **OR** the proxy (e.g. BungeeCord), **not on both**.
+          required: true
+        - label: I have included a ViaVersion dump.
+          required: true
+        - label: If applicable, I have included a paste (**not a screenshot**) of the error.
+          required: true
+        - label: I have tried a build from https://ci.viaversion.com/ and the issue still persists.
+          required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -1 +1,8 @@
 blank_issues_enabled: false
+contact_links:
+  - name: Dev builds
+    url: https://ci.viaversion.com/
+    about: Before reporting a bug, please check if using master/dev builds from our ci fixes your issue.
+  - name: ViaVersion Discord
+    url: https://discord.gg/viaversion
+    about: For smaller issues or questions, you can also join our Discord server.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,17 +0,0 @@
----
-name: Feature request
-about: Suggest an idea for ViaVersion
-
----
-
-**Is your feature request related to a problem? Please describe.**
-A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
-
-**Describe the solution you'd like**
-A clear and concise description of what you want to happen.
-
-**Describe alternatives you've considered**
-A clear and concise description of any alternative solutions or features you've considered.
-
-**Which versions is this for?**
-Does the feature apply to any specific versions? If so put them here.

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,37 @@
+name: Feature Request
+description: Suggest a feature to be added
+
+body:
+  - type: textarea
+    attributes:
+      label: Problem Description
+      description: |
+        Describe the issue you are facing or why you need the feature to be added.
+      placeholder: |
+        I am always frustrated with...
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Solution Description
+      description: |
+        Describe the solution you would like to see.
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Alternatives
+      description: |
+        Describe alternatives you have considered.
+    validations:
+      required: false
+
+  - type: textarea
+    attributes:
+      label: Additional Info
+      description: |
+        Does the feature apply to any specific version or environment?
+    validations:
+      required: false

.github/workflows/gradle.yml

@@ -0,0 +1,28 @@
+# This workflow will build a Java project with Gradle
+# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-gradle
+
+name: Java CI with Gradle
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    # Only run on PRs if the source branch is on a different repo. We do not need run everything twice.
+    if: ${{ github.event_name != 'pull_request' || github.repository != github.event.pull_request.head.repo.full_name }}
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - uses: gradle/wrapper-validation-action@v1
+    - name: Set up JDK 11
+      uses: actions/setup-java@v2
+      with:
+        distribution: 'adopt'
+        java-version: 11
+    - name: Build with Gradle
+      run: ./gradlew build
+    - uses: actions/upload-artifact@v2
+      with:
+        name: artifact
+        path: build/libs

.travis.yml

@@ -1,15 +0,0 @@
-sudo: false
-
-language: java
-jdk:
-  - openjdk11
-
-cache:
-  directories:
-  - '$HOME/.m2/repository'
-
-script:
-- mvn dependency:purge-local-repository -DactTransitively=false -DreResolve=false
-- mvn clean install -B -U
-
-install: true

LICENSE

@@ -1,21 +1,674 @@
-MIT License
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
 
-Copyright (c) 2020
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+
+  A patent license is "discriminatory" if it does not include within
+the scope of its coverage, prohibits the exercise of, or is
+conditioned on the non-exercise of one or more of the rights that are
+specifically granted under this License.  You may not convey a covered
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+for and in connection with specific products or compilations that
+contain the covered work, unless you entered into that arrangement,
+or that patent license was granted, prior to 28 March 2007.
+
+  Nothing in this License shall be construed as excluding or limiting
+any implied license or other defenses to infringement that may
+otherwise be available to you under applicable patent law.
+
+  12. No Surrender of Others' Freedom.
+
+  If conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot convey a
+covered work so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you may
+not convey it at all.  For example, if you agree to terms that obligate you
+to collect a royalty for further conveying from those to whom you convey
+the Program, the only way you could satisfy both those terms and this
+License would be to refrain entirely from conveying the Program.
+
+  13. Use with the GNU Affero General Public License.
+
+  Notwithstanding any other provision of this License, you have
+permission to link or combine any covered work with a work licensed
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+but the special requirements of the GNU Affero General Public License,
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+combination as such.
+
+  14. Revised Versions of this License.
+
+  The Free Software Foundation may publish revised and/or new versions of
+the GNU General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+  Each version is given a distinguishing version number.  If the
+Program specifies that a certain numbered version of the GNU General
+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+  If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
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+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.

README.md

@@ -1,29 +1,27 @@
 # ViaVersion - Spigot, Sponge, BungeeCord, Velocity
+
 [![Latest Release](https://img.shields.io/github/v/release/ViaVersion/ViaVersion)](https://viaversion.com)
-[![Build Status](https://travis-ci.com/ViaVersion/ViaVersion.svg?branch=master)](https://travis-ci.com/ViaVersion/ViaVersion)
+[![Build Status](https://github.com/ViaVersion/ViaVersion/actions/workflows/gradle.yml/badge.svg?branch=master)](https://github.com/ViaVersion/ViaVersion/actions)
 [![Discord](https://img.shields.io/badge/chat-on%20discord-blue.svg)](https://viaversion.com/discord)
 
 **Allows the connection of higher client versions to lower server versions**
 
 Supported Versions:
 
-![Table (https://i.imgur.com/0u20Y2u.png)](https://i.imgur.com/0u20Y2u.png)
+![Table (https://i.imgur.com/uDM9HR8.png)](https://i.imgur.com/uDM9HR8.png)
 
 On Paper you may also use ProtocolSupport, but ensure you have the right build for your server version.
 
 **User Docs:** https://docs.viaversion.com/display/VIAVERSION/
 
 
-
-
 Sources:
 --------
-**wiki.vg** (Used for various information, we also contribute back)
+**[wiki.vg](https://wiki.vg)** (Used for information regarding packet structure, we also contribute back)
 
-**Burger** (See [PAaaS](https://github.com/Matsv/Paaas))
-
-**OpenNBT** (used for slot rewriting)
+**[Burger](https://github.com/Pokechu22/Burger)** (See [PAaaS](https://github.com/Matsv/Paaas))
 
+**[OpenNBT](https://github.com/ViaVersion/OpenNBT)**
 
 
 Releases / Dev Builds:
@@ -32,7 +30,6 @@ You can find official releases here:
 
 https://www.spigotmc.org/resources/viaversion.19254/history
 
-
 ----------
 
 You can find official dev builds here:
@@ -41,12 +38,42 @@ You can find official dev builds here:
 
 **JavaDocs:** https://jd.viaversion.com
 
-**Maven Repo:** https://repo.viaversion.com
+**Maven Repository:**
+```xml
+<repository>
+    <id>viaversion-repo</id>
+    <url>https://repo.viaversion.com</url>
+</repository>
+```
+
+**API-artifact:**
+```xml
+<dependency>
+    <groupId>com.viaversion</groupId>
+    <artifactId>viaversion-api</artifactId>
+    <version>LATEST</version>
+    <scope>provided</scope>
+</dependency>
+```
+
+Replace the version depending on your needs.
+
+If you need access to the existing protocol or platform implementations, use the parent artifact `viaversion`.
+Please note the [differences in licensing](#license).
+
+
+Building:
+--------
+After cloning this repository, build the project with Gradle by running `./gradlew build` and take the created jar out of
+the `build/libs` directory.
+
 
 License:
 --------
+The entirety of the [API directory](api) (including the legacy API directory) is licensed under the MIT License; see [licenses/MIT.md](licenses/MIT.md) for
+details.
 
-MIT License, see LICENSE for more details.
+Everything else, unless explicitly stated otherwise, is licensed under the GNU General Public License, including the end
+product as a whole; see [licenses/GPL.md](licenses/GPL.md) for details.
 
-
-Special thanks to all our [Contributors](https://github.com/ViaVersion/ViaVersion/graphs/contributors)
+Special thanks to all our [Contributors](https://github.com/ViaVersion/ViaVersion/graphs/contributors).

adventure/build.gradle.kts

@@ -0,0 +1,25 @@
+plugins {
+    id("com.github.johnrengelman.shadow")
+}
+
+// Shade and relocate adventure in an extra module, so that common/the rest can directly depend on a
+// relocated adventure without breaking native platform's adventure usage with project wide relocation
+tasks {
+    shadowJar {
+        relocate("net.kyori", "com.viaversion.viaversion.libs.kyori")
+    }
+    build {
+        dependsOn(shadowJar)
+    }
+}
+
+dependencies {
+    api(libs.bundles.adventure) {
+        exclude("org.checkerframework")
+        exclude("net.kyori", "adventure-api")
+        exclude("net.kyori", "adventure-bom")
+        exclude("com.google.code.gson", "gson")
+    }
+}
+
+publishShadowJar()

api-legacy/build.gradle.kts

@@ -0,0 +1,3 @@
+dependencies {
+    compileOnly(projects.viaversionApi)
+}

api-legacy/src/main/java/us/myles/ViaVersion/api/Via.java

@@ -0,0 +1,102 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package us.myles.ViaVersion.api;
+
+import io.netty.buffer.ByteBuf;
+import us.myles.ViaVersion.api.boss.BossBar;
+import us.myles.ViaVersion.api.boss.BossColor;
+import us.myles.ViaVersion.api.boss.BossStyle;
+
+import java.util.SortedSet;
+import java.util.UUID;
+
+/**
+ * @deprecated may be removed at some point, use {@link com.viaversion.viaversion.api.Via}
+ */
+@Deprecated
+public class Via<T> implements ViaAPI<T> {
+
+    private static final ViaAPI INSTANCE = new Via();
+
+    private Via() {
+    }
+
+    @Deprecated
+    public static ViaAPI getAPI() {
+        return INSTANCE;
+    }
+
+    @Override
+    public int getPlayerVersion(T player) {
+        return com.viaversion.viaversion.api.Via.getAPI().getPlayerVersion(player);
+    }
+
+    @Override
+    public int getPlayerVersion(UUID uuid) {
+        return com.viaversion.viaversion.api.Via.getAPI().getPlayerVersion(uuid);
+    }
+
+    @Override
+    public boolean isInjected(UUID playerUUID) {
+        return com.viaversion.viaversion.api.Via.getAPI().isInjected(playerUUID);
+    }
+
+    @Override
+    public String getVersion() {
+        return com.viaversion.viaversion.api.Via.getAPI().getVersion();
+    }
+
+    @Override
+    public void sendRawPacket(T player, ByteBuf packet) {
+        com.viaversion.viaversion.api.Via.getAPI().sendRawPacket(player, packet);
+    }
+
+    @Override
+    public void sendRawPacket(UUID uuid, ByteBuf packet) {
+        com.viaversion.viaversion.api.Via.getAPI().sendRawPacket(uuid, packet);
+    }
+
+    @Override
+    public BossBar createBossBar(String title, BossColor color, BossStyle style) {
+        return new BossBar(com.viaversion.viaversion.api.Via.getAPI().legacyAPI().createLegacyBossBar(title,
+                com.viaversion.viaversion.api.legacy.bossbar.BossColor.values()[color.ordinal()],
+                com.viaversion.viaversion.api.legacy.bossbar.BossStyle.values()[style.ordinal()]));
+    }
+
+    @Override
+    public BossBar createBossBar(String title, float health, BossColor color, BossStyle style) {
+        return new BossBar(com.viaversion.viaversion.api.Via.getAPI().legacyAPI().createLegacyBossBar(title, health,
+                com.viaversion.viaversion.api.legacy.bossbar.BossColor.values()[color.ordinal()],
+                com.viaversion.viaversion.api.legacy.bossbar.BossStyle.values()[style.ordinal()]));
+    }
+
+    @Override
+    public SortedSet<Integer> getSupportedVersions() {
+        return com.viaversion.viaversion.api.Via.getAPI().getSupportedVersions();
+    }
+
+    @Override
+    public SortedSet<Integer> getFullSupportedVersions() {
+        return com.viaversion.viaversion.api.Via.getAPI().getFullSupportedVersions();
+    }
+}

api-legacy/src/main/java/us/myles/ViaVersion/api/ViaAPI.java

@@ -0,0 +1,63 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package us.myles.ViaVersion.api;
+
+import com.viaversion.viaversion.api.Via;
+import io.netty.buffer.ByteBuf;
+import us.myles.ViaVersion.api.boss.BossBar;
+import us.myles.ViaVersion.api.boss.BossColor;
+import us.myles.ViaVersion.api.boss.BossStyle;
+
+import java.util.SortedSet;
+import java.util.UUID;
+
+/**
+ * @deprecated may be removed at some point, use {@link Via#getAPI()}
+ */
+@Deprecated
+public interface ViaAPI<T> {
+
+    int getPlayerVersion(T player);
+
+    int getPlayerVersion(UUID uuid);
+
+    default boolean isPorted(UUID playerUUID) {
+        return isInjected(playerUUID);
+    }
+
+    boolean isInjected(UUID playerUUID);
+
+    String getVersion();
+
+    void sendRawPacket(T player, ByteBuf packet);
+
+    void sendRawPacket(UUID uuid, ByteBuf packet);
+
+    BossBar createBossBar(String title, BossColor color, BossStyle style);
+
+    BossBar createBossBar(String title, float health, BossColor color, BossStyle style);
+
+    SortedSet<Integer> getSupportedVersions();
+
+    SortedSet<Integer> getFullSupportedVersions();
+}

api-legacy/src/main/java/us/myles/ViaVersion/api/boss/BossBar.java

@@ -0,0 +1,133 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package us.myles.ViaVersion.api.boss;
+
+import java.util.Set;
+import java.util.UUID;
+
+@Deprecated
+public class BossBar<T> {
+
+    private final com.viaversion.viaversion.api.legacy.bossbar.BossBar bossBar;
+
+    public BossBar(com.viaversion.viaversion.api.legacy.bossbar.BossBar bossBar) {
+        this.bossBar = bossBar;
+    }
+
+    public String getTitle() {
+        return bossBar.getTitle();
+    }
+
+    public BossBar setTitle(String title) {
+        bossBar.setTitle(title);
+        return this;
+    }
+
+    public float getHealth() {
+        return bossBar.getHealth();
+    }
+
+    public BossBar setHealth(float health) {
+        bossBar.setHealth(health);
+        return this;
+    }
+
+    public BossColor getColor() {
+        return BossColor.values()[bossBar.getColor().ordinal()];
+    }
+
+    public BossBar setColor(BossColor color) {
+        bossBar.setColor(com.viaversion.viaversion.api.legacy.bossbar.BossColor.values()[color.ordinal()]);
+        return this;
+    }
+
+    public BossStyle getStyle() {
+        return BossStyle.values()[bossBar.getStyle().ordinal()];
+    }
+
+    public BossBar setStyle(BossStyle style) {
+        bossBar.setStyle(com.viaversion.viaversion.api.legacy.bossbar.BossStyle.values()[style.ordinal()]);
+        return this;
+    }
+
+    @Deprecated
+    public BossBar addPlayer(T player) {
+        return this;
+    }
+
+    public BossBar addPlayer(UUID player) {
+        bossBar.addPlayer(player);
+        return this;
+    }
+
+    @Deprecated
+    public BossBar addPlayers(T... players) {
+        return this;
+    }
+
+    @Deprecated
+    public BossBar removePlayer(T player) {
+        return this;
+    }
+
+    public BossBar removePlayer(UUID uuid) {
+        bossBar.removePlayer(uuid);
+        return this;
+    }
+
+    public BossBar addFlag(BossFlag flag) {
+        bossBar.addFlag(com.viaversion.viaversion.api.legacy.bossbar.BossFlag.values()[flag.ordinal()]);
+        return this;
+    }
+
+    public BossBar removeFlag(BossFlag flag) {
+        bossBar.removeFlag(com.viaversion.viaversion.api.legacy.bossbar.BossFlag.values()[flag.ordinal()]);
+        return this;
+    }
+
+    public boolean hasFlag(BossFlag flag) {
+        return bossBar.hasFlag(com.viaversion.viaversion.api.legacy.bossbar.BossFlag.values()[flag.ordinal()]);
+    }
+
+    public Set<UUID> getPlayers() {
+        return bossBar.getPlayers();
+    }
+
+    public BossBar show() {
+        bossBar.show();
+        return this;
+    }
+
+    public BossBar hide() {
+        bossBar.hide();
+        return this;
+    }
+
+    public boolean isVisible() {
+        return bossBar.isVisible();
+    }
+
+    public UUID getId() {
+        return bossBar.getId();
+    }
+}

api-legacy/src/main/java/us/myles/ViaVersion/api/boss/BossColor.java

@@ -0,0 +1,45 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package us.myles.ViaVersion.api.boss;
+
+@Deprecated
+public enum BossColor {
+
+    PINK(0),
+    BLUE(1),
+    RED(2),
+    GREEN(3),
+    YELLOW(4),
+    PURPLE(5),
+    WHITE(6);
+
+    private final int id;
+
+    BossColor(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+        return id;
+    }
+}

api-legacy/src/main/java/us/myles/ViaVersion/api/boss/BossFlag.java

@@ -0,0 +1,40 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package us.myles.ViaVersion.api.boss;
+
+@Deprecated
+public enum BossFlag {
+
+    DARKEN_SKY(1),
+    PLAY_BOSS_MUSIC(2);
+
+    private final int id;
+
+    BossFlag(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+        return id;
+    }
+}

api-legacy/src/main/java/us/myles/ViaVersion/api/boss/BossStyle.java

@@ -0,0 +1,43 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package us.myles.ViaVersion.api.boss;
+
+@Deprecated
+public enum BossStyle {
+
+    SOLID(0),
+    SEGMENTED_6(1),
+    SEGMENTED_10(2),
+    SEGMENTED_12(3),
+    SEGMENTED_20(4);
+
+    private final int id;
+
+    BossStyle(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+        return id;
+    }
+}

api-legacy/src/main/java/us/myles/ViaVersion/api/protocol/ProtocolRegistry.java

@@ -0,0 +1,33 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package us.myles.ViaVersion.api.protocol;
+
+/**
+ * @deprecated may be removed at some point, use {@link com.viaversion.viaversion.api.protocol.ProtocolManager}
+ */
+@Deprecated
+public class ProtocolRegistry {
+
+    @Deprecated
+    public static int SERVER_PROTOCOL = -1;
+}

api-legacy/src/main/java/us/myles/ViaVersion/api/protocol/ProtocolVersion.java

@@ -1,22 +1,48 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
 package us.myles.ViaVersion.api.protocol;
 
 import com.google.common.base.Preconditions;
+import com.viaversion.viaversion.api.protocol.version.VersionRange;
 import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 
+/**
+ * @deprecated will no longer be updated and may be removed at some point, use {@link com.viaversion.viaversion.api.protocol.version.ProtocolVersion}
+ */
+@Deprecated
 public class ProtocolVersion {
     private static final Int2ObjectMap<ProtocolVersion> versions = new Int2ObjectOpenHashMap<>();
     private static final List<ProtocolVersion> versionList = new ArrayList<>();
 
-    // Before the Netty rewrite
     public static final ProtocolVersion v1_4_6 = register(51, "1.4.6/7", new VersionRange("1.4", 6, 7));
     public static final ProtocolVersion v1_5_1 = register(60, "1.5.1");
     public static final ProtocolVersion v1_5_2 = register(61, "1.5.2");
@@ -24,7 +50,6 @@ public class ProtocolVersion {
     public static final ProtocolVersion v_1_6_2 = register(74, "1.6.2");
     public static final ProtocolVersion v_1_6_3 = register(77, "1.6.3");
     public static final ProtocolVersion v_1_6_4 = register(78, "1.6.4");
-    // After the Netty rewrite
     public static final ProtocolVersion v1_7_1 = register(4, "1.7-1.7.5", new VersionRange("1.7", 0, 5));
     public static final ProtocolVersion v1_7_6 = register(5, "1.7.6-1.7.10", new VersionRange("1.7", 6, 10));
     public static final ProtocolVersion v1_8 = register(47, "1.8.x");
@@ -53,7 +78,7 @@ public class ProtocolVersion {
     public static final ProtocolVersion v1_16_1 = register(736, "1.16.1");
     public static final ProtocolVersion v1_16_2 = register(751, "1.16.2");
     public static final ProtocolVersion v1_16_3 = register(753, "1.16.3");
-    public static final ProtocolVersion v1_16_4 = register(754, "1.16.4");
+    public static final ProtocolVersion v1_16_4 = register(754, "1.16.4/5", new VersionRange("1.16", 4, 5));
     public static final ProtocolVersion unknown = register(-1, "UNKNOWN");
 
     public static ProtocolVersion register(int version, String name) {
@@ -82,8 +107,7 @@ public class ProtocolVersion {
         return versions.containsKey(id);
     }
 
-    @NotNull
-    public static ProtocolVersion getProtocol(int id) {
+    public static @NonNull ProtocolVersion getProtocol(int id) {
         ProtocolVersion protocolVersion = versions.get(id);
         if (protocolVersion != null) {
             return protocolVersion;
@@ -100,8 +124,7 @@ public class ProtocolVersion {
         return Collections.unmodifiableList(new ArrayList<>(versions.values()));
     }
 
-    @Nullable
-    public static ProtocolVersion getClosest(String protocol) {
+    public static @Nullable ProtocolVersion getClosest(String protocol) {
         for (ProtocolVersion version : versions.values()) {
             String name = version.getName();
             if (name.equals(protocol)) {
@@ -141,7 +164,7 @@ public class ProtocolVersion {
 
         Preconditions.checkArgument(!versionWildcard || versionRange == null, "A version cannot be a wildcard and a range at the same time!");
         if (versionRange != null) {
-            includedVersions = new HashSet<>();
+            includedVersions = new LinkedHashSet<>();
             for (int i = versionRange.getRangeFrom(); i <= versionRange.getRangeTo(); i++) {
                 if (i == 0) {
                     includedVersions.add(versionRange.getBaseVersion()); // Keep both the base version and with ".0" appended
@@ -154,63 +177,36 @@ public class ProtocolVersion {
         }
     }
 
-    /**
-     * @return release version
-     */
     public int getVersion() {
         return version;
     }
 
-    /**
-     * @return snapshot protocol version without the snapshot indicator bit
-     * @throws IllegalArgumentException if the version if not a snapshot version
-     * @see #isSnapshot()
-     */
     public int getSnapshotVersion() {
         Preconditions.checkArgument(isSnapshot());
         return snapshotVersion;
     }
 
-    /**
-     * @return snapshot protocol version with the snapshot indicator bit
-     * @throws IllegalArgumentException if the version if not a snapshot version
-     * @see #isSnapshot()
-     */
     public int getFullSnapshotVersion() {
         Preconditions.checkArgument(isSnapshot());
         return (1 << 30) | snapshotVersion; // Bit indicating snapshot versions
     }
 
-    /**
-     * @return release version if release, snapshot version (with the snapshot indicator bit) if snapshot
-     */
     public int getOriginalVersion() {
         return snapshotVersion == -1 ? version : ((1 << 30) | snapshotVersion);
     }
 
-    /**
-     * @return true if the protocol includes a range of versions (but not an entire major version range), for example 1.7-1.7.5
-     * @see #getIncludedVersions()
-     */
+    public boolean isKnown() {
+        return version != -1;
+    }
+
     public boolean isRange() {
         return includedVersions.size() != 1;
     }
 
-    /**
-     * Returns an immutable set of all included versions if the protocol is a version range.
-     * If the protocol only includes a single Minecraft version or the entire major version as a wildcard ({@link #isVersionWildcard()}),
-     * the set will only contain the string given in {@link #getName()}.
-     *
-     * @return immutable set of all included versions if the protocol is a version range
-     * @see #isRange()
-     */
     public Set<String> getIncludedVersions() {
         return Collections.unmodifiableSet(includedVersions);
     }
 
-    /**
-     * @return true if the protocol includes an entire major version range (for example 1.8.x)
-     */
     public boolean isVersionWildcard() {
         return versionWildcard;
     }
@@ -223,11 +219,6 @@ public class ProtocolVersion {
         return snapshotVersion != -1;
     }
 
-    /**
-     * @return release version
-     * @deprecated ambiguous, see {@link #getOriginalVersion()}, {@link #getVersion()}, and {@link #getSnapshotVersion()}
-     */
-    @Deprecated
     public int getId() {
         return version;
     }
@@ -248,6 +239,6 @@ public class ProtocolVersion {
 
     @Override
     public String toString() {
-        return String.format("%s(%d)", this.name, this.version);
+        return String.format("%s (%d)", this.name, this.version);
     }
 }

api/build.gradle.kts

@@ -0,0 +1,27 @@
+plugins {
+    id("net.kyori.blossom")
+    id("via.shadow-conventions")
+}
+
+blossom {
+    replaceToken("\$VERSION", project.version)
+    replaceToken("\$IMPL_VERSION", "git-ViaVersion-${project.version}:${rootProject.latestCommitHash()}")
+}
+
+dependencies {
+    api(projects.adventure) {
+        targetConfiguration = "shadow"
+    }
+    api(libs.fastutil)
+    api(libs.openNBT)
+    api(libs.gson)
+
+    compileOnlyApi(libs.snakeYaml)
+    compileOnlyApi(libs.netty)
+    compileOnlyApi(libs.guava)
+    compileOnlyApi(libs.checkerQual)
+}
+
+java {
+    withJavadocJar()
+}

api/src/main/java/com/viaversion/viaversion/api/Via.java

@@ -0,0 +1,81 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api;
+
+import com.google.common.base.Preconditions;
+import com.viaversion.viaversion.api.configuration.ViaVersionConfig;
+import com.viaversion.viaversion.api.platform.ViaPlatform;
+
+public final class Via {
+    private static ViaManager manager;
+
+    /**
+     * Returns the API associated with the current platform.
+     *
+     * @return API instance
+     * @throws IllegalArgumentException if the platform has not loaded yet
+     */
+    public static ViaAPI getAPI() {
+        return manager().getPlatform().getApi();
+    }
+
+    /**
+     * Returns the ViaManager with methods beyond the simple API {@link ViaAPI} provides.
+     *
+     * @return manager to interact with various Via parts
+     * @throws IllegalArgumentException if the platform has not loaded yet
+     */
+    public static ViaManager getManager() {
+        return manager();
+    }
+
+    /**
+     * Returns the config associated with the current platform.
+     *
+     * @return config instance
+     * @throws IllegalArgumentException if the platform has not loaded yet
+     */
+    public static ViaVersionConfig getConfig() {
+        return manager().getPlatform().getConf();
+    }
+
+    public static ViaPlatform getPlatform() {
+        return manager().getPlatform();
+    }
+
+    /**
+     * Register the ViaManager associated with the platform.
+     *
+     * @param viaManager The ViaManager
+     * @throws IllegalArgumentException if the manager has already been set
+     */
+    public static void init(ViaManager viaManager) {
+        Preconditions.checkArgument(manager == null, "ViaManager is already set");
+        Via.manager = viaManager;
+    }
+
+    private static ViaManager manager() {
+        Preconditions.checkArgument(manager != null, "ViaVersion has not loaded the platform yet");
+        return manager;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/ViaAPI.java

@@ -0,0 +1,148 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api;
+
+import com.viaversion.viaversion.api.connection.ConnectionManager;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.legacy.LegacyViaAPI;
+import com.viaversion.viaversion.api.platform.ViaPlatform;
+import com.viaversion.viaversion.api.protocol.ProtocolManager;
+import com.viaversion.viaversion.api.protocol.version.ServerProtocolVersion;
+import io.netty.buffer.ByteBuf;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.SortedSet;
+import java.util.UUID;
+
+/**
+ * General api point. For more specialized api methods, see {@link Via#getManager()}.
+ *
+ * @param <T> player type for the specific platform
+ * @see ViaManager
+ * @see ProtocolManager
+ * @see ConnectionManager
+ * @see ViaPlatform
+ */
+public interface ViaAPI<T> {
+
+    /**
+     * Returns the API version incremented with meaningful API changes.
+     * This includes breaking changes to existing API and larger additions.
+     *
+     * @return API version incremented with meaningful API changes
+     */
+    default int apiVersion() {
+        return 3;
+    }
+
+    /**
+     * Returns the server's protocol version info.
+     *
+     * @return the server's protocol version info
+     */
+    ServerProtocolVersion getServerVersion();
+
+    /**
+     * Returns the protocol version of a player.
+     * This will also retrieve the version from ProtocolSupport if it's being used.
+     *
+     * @param player the platform's player object, e.g. Bukkit this is Player
+     * @return protocol version, for example (47=1.8-1.8.8, 107=1.9, 108=1.9.1), or -1 if no longer connected
+     */
+    int getPlayerVersion(T player);
+
+    /**
+     * Returns the protocol version of a player.
+     *
+     * @param uuid UUID of a player
+     * @return protocol version, for example (47=1.8-1.8.8, 107=1.9, 108=1.9.1), or -1 if not connected
+     */
+    int getPlayerVersion(UUID uuid);
+
+    /**
+     * Returns whether Via injected into this player connection.
+     *
+     * @param uuid uuid of the player
+     * @return whether Via has a cached a UserConnection for this player
+     */
+    boolean isInjected(UUID uuid);
+
+    /**
+     * Returns the Via injected UserConnection if present.
+     *
+     * @param uuid uuid of the player
+     * @return user connection if present
+     */
+    @Nullable UserConnection getConnection(UUID uuid);
+
+    /**
+     * Returns the version of the plugin.
+     *
+     * @return plugin version
+     */
+    String getVersion();
+
+    /**
+     * Sends a raw packet to the player.
+     *
+     * @param player the platform's player object, e.g. for Bukkit this is Player
+     * @param packet the packet; you need a VarInt Id, then the packet contents
+     * @throws IllegalArgumentException if the player is not injected by Via
+     */
+    void sendRawPacket(T player, ByteBuf packet);
+
+    /**
+     * Sends a raw packet to the player.
+     *
+     * @param uuid   the uuid from the player to send packet
+     * @param packet the packet; you need a VarInt Id, then the packet contents
+     * @throws IllegalArgumentException if the player is not injected by Via
+     */
+    void sendRawPacket(UUID uuid, ByteBuf packet);
+
+    /**
+     * Returns the supported protocol versions.
+     * This method removes any blocked protocol versions.
+     *
+     * @return a list of protocol versions
+     * @see #getFullSupportedVersions() for a full list
+     */
+    SortedSet<Integer> getSupportedVersions();
+
+    /**
+     * Returns the supported protocol versions, including blocked protocols.
+     *
+     * @return a list of protocol versions
+     */
+    SortedSet<Integer> getFullSupportedVersions();
+
+    /**
+     * Returns legacy api only applicable on/to legacy versions.
+     * <p>
+     * These methods are safe to use and are unlikely to be removed,
+     * but it is important to be aware of their limited use.
+     *
+     * @return legacy api only applicable on/to legacy versions
+     */
+    LegacyViaAPI<T> legacyAPI();
+}

api/src/main/java/com/viaversion/viaversion/api/ViaManager.java

@@ -0,0 +1,114 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api;
+
+import com.viaversion.viaversion.api.command.ViaVersionCommand;
+import com.viaversion.viaversion.api.connection.ConnectionManager;
+import com.viaversion.viaversion.api.platform.ViaInjector;
+import com.viaversion.viaversion.api.platform.ViaPlatform;
+import com.viaversion.viaversion.api.platform.ViaPlatformLoader;
+import com.viaversion.viaversion.api.platform.providers.ViaProviders;
+import com.viaversion.viaversion.api.protocol.ProtocolManager;
+
+import java.util.Set;
+
+public interface ViaManager {
+
+    /**
+     * Returns the protocol manager for registering/getting protocols and their mapping data loading.
+     *
+     * @return protocol manager
+     */
+    ProtocolManager getProtocolManager();
+
+    /**
+     * Returns platform for handling platform specific configuration, tasks, and plugin data.
+     *
+     * @return platform
+     */
+    ViaPlatform<?> getPlatform();
+
+    /**
+     * Returns the userconnection manager for handling clients connected to the server.
+     *
+     * @return userconnection manager
+     */
+    ConnectionManager getConnectionManager();
+
+    /**
+     * Returns the manager for Via providers.
+     *
+     * @return provider manager
+     */
+    ViaProviders getProviders();
+
+    /**
+     * Returns the injector for injecting netty handlers and initially getting the server protocol version.
+     *
+     * @return injector
+     */
+    ViaInjector getInjector();
+
+    /**
+     * Returns the command handler for managing ViaVersion subcommands.
+     *
+     * @return command handler
+     */
+    ViaVersionCommand getCommandHandler();
+
+    /**
+     * Returns the platform loader responsible for registering listeners, providers and such.
+     *
+     * @return platform loader
+     */
+    ViaPlatformLoader getLoader();
+
+    /**
+     * If debug is enabled, packets and other otherwise suppressed warnings will be logged.
+     *
+     * @return true if enabled
+     */
+    boolean isDebug();
+
+    /**
+     * Sets the debug mode. If enabled, packets and other otherwise suppressed warnings will be logged.
+     *
+     * @param debug whether debug should be enabled
+     */
+    void setDebug(boolean debug);
+
+    /**
+     * Returns a mutable set of self-added subplatform version strings.
+     * This set is expanded by the subplatform itself (e.g. ViaBackwards), and may not contain all running ones.
+     *
+     * @return mutable set of subplatform versions
+     */
+    Set<String> getSubPlatforms();
+
+    /**
+     * Adds a runnable to be executed when ViaVersion has finished its init before the full server load.
+     *
+     * @param runnable runnable to be executed
+     */
+    void addEnableListener(Runnable runnable);
+}

api/src/main/java/com/viaversion/viaversion/api/command/ViaCommandSender.java

@@ -0,0 +1,56 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.command;
+
+import java.util.UUID;
+
+public interface ViaCommandSender {
+    /**
+     * Check if the sender has a permission.
+     *
+     * @param permission Permission string eg. viaversion.admin
+     * @return True if the sender has the permission
+     */
+    boolean hasPermission(String permission);
+
+    /**
+     * Send a message to the sender
+     *
+     * @param msg The message to send
+     */
+    void sendMessage(String msg);
+
+    /**
+     * Get the senders UUID.
+     *
+     * @return The senders UUID
+     */
+    UUID getUUID();
+
+    /**
+     * Get the senders name.
+     *
+     * @return The senders name
+     */
+    String getName();
+}

api/src/main/java/com/viaversion/viaversion/api/command/ViaSubCommand.java

@@ -0,0 +1,105 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.command;
+
+import com.viaversion.viaversion.util.ChatColorUtil;
+
+import java.util.Collections;
+import java.util.List;
+
+public abstract class ViaSubCommand {
+
+    /**
+     * Subcommand name
+     *
+     * @return The commands name
+     */
+    public abstract String name();
+
+    /**
+     * subcommand description, this'll show in /viaversion list
+     *
+     * @return The commands description
+     */
+    public abstract String description();
+
+    /**
+     * Usage example:
+     * "playerversion [name]"
+     *
+     * @return The commands usage
+     */
+    public String usage() {
+        return name();
+    }
+
+    /**
+     * Permission, null for everyone
+     *
+     * @return The permission required to use the commands
+     */
+    public String permission() {
+        return "viaversion.admin";
+    }
+
+    /**
+     * Gets triggered on execution
+     *
+     * @param sender Command sender
+     * @param args   Arguments
+     * @return commands executed succesfully if false, show usage
+     */
+    public abstract boolean execute(ViaCommandSender sender, String[] args);
+
+    /**
+     * Yay, possibility to implement tab-completion
+     *
+     * @param sender Command sender
+     * @param args   args
+     * @return tab complete possibilities
+     */
+    public List<String> onTabComplete(ViaCommandSender sender, String[] args) {
+        return Collections.emptyList();
+    }
+
+    /**
+     * Replaces color codes in a string.
+     *
+     * @param s string to replace
+     * @return output String
+     */
+    public static String color(String s) {
+        return ChatColorUtil.translateAlternateColorCodes(s);
+    }
+
+    /**
+     * Send a color coded string with replacements to a user.
+     *
+     * @param sender  target to send the message to
+     * @param message message
+     * @param args    objects to replace
+     */
+    public static void sendMessage(ViaCommandSender sender, String message, Object... args) {
+        sender.sendMessage(color(args == null ? message : String.format(message, args)));
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/command/ViaVersionCommand.java

@@ -0,0 +1,73 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.command;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.List;
+
+public interface ViaVersionCommand {
+    /**
+     * Register your own subcommand inside ViaVersion
+     *
+     * @param command Your own SubCommand instance to handle it.
+     * @throws Exception throws an exception when the subcommand already exists or if it's not valid, example: spacee
+     */
+    void registerSubCommand(ViaSubCommand command) throws Exception;
+
+    /**
+     * Check if a subcommand is registered.
+     *
+     * @param name Subcommand name
+     * @return true if it exists
+     */
+    boolean hasSubCommand(String name);
+
+    /**
+     * Get subcommand instance by name
+     *
+     * @param name subcommand name
+     * @return ViaSubCommand instance
+     */
+    @Nullable ViaSubCommand getSubCommand(String name);
+
+    /**
+     * Executed when the Command sender executes the commands
+     *
+     * @param sender Sender object
+     * @param args   arguments provided
+     * @return was successful
+     */
+    boolean onCommand(ViaCommandSender sender, String[] args);
+
+    /**
+     * Executed when the Command sender tab-completes
+     *
+     * @param sender Sender object
+     * @param args   arguments provided
+     * @return was successful
+     */
+    List<String> onTabComplete(ViaCommandSender sender, String[] args);
+
+    void showHelp(ViaCommandSender sender);
+}

api/src/main/java/com/viaversion/viaversion/api/configuration/ConfigurationProvider.java

@@ -0,0 +1,53 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.configuration;
+
+import java.util.Map;
+
+public interface ConfigurationProvider {
+
+    /**
+     * Sets the specified path to the given value.
+     *
+     * @param path  Path of the object to set.
+     * @param value New value to set the path to
+     */
+    void set(String path, Object value);
+
+    /**
+     * Saves the config
+     */
+    void saveConfig();
+
+    /**
+     * Reloads the config
+     */
+    void reloadConfig();
+
+    /**
+     * Get all the configuration values
+     *
+     * @return Map with key-values
+     */
+    Map<String, Object> getValues();
+}

api/src/main/java/com/viaversion/viaversion/api/configuration/ViaVersionConfig.java

@@ -1,4 +1,26 @@
-package us.myles.ViaVersion.api;
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.configuration;
 
 import it.unimi.dsi.fastutil.ints.IntSet;
 
@@ -54,6 +76,25 @@ public interface ViaVersionConfig {
      */
     boolean isShieldBlocking();
 
+    /**
+     * Whether the player can block with the shield without a delay.
+     * <p>
+     * This option requires {@link #isShowShieldWhenSwordInHand()} to be disabled
+     *
+     * @return {@code true} if non delayed shield blocking is enabled.
+     */
+    boolean isNoDelayShieldBlocking();
+
+    /**
+     * Puts the shield into the second hand when holding a sword.
+     * The shield will disappear when switching to another item.
+     * <p>
+     * This option requires {@link #isShieldBlocking()} to be enabled
+     *
+     * @return {@code true} if the shield should appear when holding a sword
+     */
+    boolean isShowShieldWhenSwordInHand();
+
     /**
      * Get if armor stand positions are fixed so holograms show up at the correct height in 1.9 &amp; 1.10
      *
@@ -366,4 +407,11 @@ public interface ViaVersionConfig {
      * @return true if enabled
      */
     boolean isIgnoreLong1_16ChannelNames();
+
+    /**
+     * Force 1.17+ client to accept the server resource pack.
+     *
+     * @return true if enabled
+     */
+    boolean isForcedUse1_17ResourcePack();
 }

api/src/main/java/com/viaversion/viaversion/api/connection/ConnectionManager.java

@@ -0,0 +1,104 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.connection;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+
+/**
+ * Handles injected UserConnections
+ */
+public interface ConnectionManager {
+
+    /**
+     * Returns if Via injected into this player connection.
+     *
+     * @param playerId player uuid
+     * @return true if the player is handled by Via
+     */
+    boolean isClientConnected(UUID playerId);
+
+    /**
+     * Frontend connections will have the UUID stored. Override this if your platform isn't always frontend.
+     * UUIDs can't be duplicate between frontend connections.
+     *
+     * @return true if the user is a frontend connection
+     */
+    default boolean isFrontEnd(UserConnection connection) {
+        return !connection.isClientSide();
+    }
+
+    /**
+     * Returns the frontend UserConnection from the player connected to this proxy server
+     * Returns null when there isn't a server or connection was not found
+     * When ViaVersion is reloaded, this method may not return some players.
+     * May not return ProtocolSupport players.
+     * <p>
+     * Note that connections are removed as soon as their channel is closed,
+     * so avoid using this method during player quits for example.
+     *
+     * @return frontend UserConnection of the player connected to this proxy server
+     */
+    @Nullable UserConnection getConnectedClient(UUID clientIdentifier);
+
+    /**
+     * Returns the UUID from the frontend connection to this proxy server
+     * Returns null when there isn't a server or this connection isn't frontend or it doesn't have an id
+     * When ViaVersion is reloaded, this method may not return some players.
+     * May not return ProtocolSupport players.
+     * <p>
+     * Note that connections are removed as soon as their channel is closed,
+     * so avoid using this method during player quits for example.
+     *
+     * @return UUID of the frontend connection to this proxy server
+     */
+    @Nullable UUID getConnectedClientId(UserConnection connection);
+
+    /**
+     * Returns all UserConnections which are registered
+     * May contain duplicated UUIDs on multiple ProtocolInfo.
+     * May contain frontend, backend and/or client-sided connections.
+     * When ViaVersion is reloaded, this method may not return some players.
+     * May not contain ProtocolSupport players.
+     *
+     * @return connected UserConnections
+     */
+    Set<UserConnection> getConnections();
+
+    /**
+     * Returns a map containing the UUIDs and frontend UserConnections from players connected to this proxy server
+     * Returns empty list when there isn't a server
+     * When ViaVersion is reloaded, this method may not return some players.
+     * May not contain ProtocolSupport players.
+     *
+     * @return map containing the UUIDs and frontend UserConnections from players connected to this proxy server
+     */
+    Map<UUID, UserConnection> getConnectedClients();
+
+    void onLoginSuccess(UserConnection connection);
+
+    void onDisconnect(UserConnection connection);
+}

api/src/main/java/com/viaversion/viaversion/api/connection/ProtocolInfo.java

@@ -0,0 +1,97 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.connection;
+
+import com.viaversion.viaversion.api.protocol.ProtocolPipeline;
+import com.viaversion.viaversion.api.protocol.packet.State;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.UUID;
+
+public interface ProtocolInfo {
+
+    /**
+     * Returns the protocol state the user is currently in.
+     *
+     * @return protocol state
+     */
+    State getState();
+
+    void setState(State state);
+
+    /**
+     * Returns the user's protocol version, or -1 if not set.
+     * This is set during the {@link State#HANDSHAKE} state.
+     *
+     * @return protocol version, or -1 if not set
+     */
+    int getProtocolVersion();
+
+    void setProtocolVersion(int protocolVersion);
+
+    /**
+     * Returns the server protocol version the user is connected to, or -1 if not set.
+     * This is set during the {@link State#HANDSHAKE} state.
+     *
+     * @return server protocol version, or -1 if not set
+     */
+    int getServerProtocolVersion();
+
+    void setServerProtocolVersion(int serverProtocolVersion);
+
+    /**
+     * Returns the username associated with this connection.
+     * This is set once the connection enters the {@link State#PLAY} state.
+     *
+     * @return username, set when entering the {@link State#PLAY} state
+     */
+    @Nullable String getUsername();
+
+    void setUsername(String username);
+
+    /**
+     * Returns the uuid associated with this connection.
+     * This is set once the connection enters the {@link State#PLAY} state.
+     *
+     * @return uuid, set when entering the {@link State#PLAY} state
+     */
+    @Nullable UUID getUuid();
+
+    void setUuid(UUID uuid);
+
+    /**
+     * Returns the user's pipeline.
+     *
+     * @return protocol pipeline
+     */
+    ProtocolPipeline getPipeline();
+
+    void setPipeline(ProtocolPipeline pipeline);
+
+    /**
+     * Returns the user connection this info represents.
+     *
+     * @return user connection
+     */
+    UserConnection getUser();
+}

api/src/main/java/com/viaversion/viaversion/api/connection/StorableObject.java

@@ -0,0 +1,32 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.connection;
+
+/**
+ * Dummy interface used to explicitly identify objects storable in user connections.
+ *
+ * @see UserConnection#get(Class)
+ * @see UserConnection#put(StorableObject)
+ */
+public interface StorableObject {
+}

api/src/main/java/com/viaversion/viaversion/api/connection/StoredObject.java

@@ -0,0 +1,35 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.connection;
+
+public abstract class StoredObject implements StorableObject {
+    private final UserConnection user;
+
+    protected StoredObject(UserConnection user) {
+        this.user = user;
+    }
+
+    public UserConnection getUser() {
+        return user;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/connection/UserConnection.java

@@ -0,0 +1,307 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.connection;
+
+import com.viaversion.viaversion.api.configuration.ViaVersionConfig;
+import com.viaversion.viaversion.api.data.entity.EntityTracker;
+import com.viaversion.viaversion.api.protocol.Protocol;
+import com.viaversion.viaversion.api.protocol.packet.PacketTracker;
+import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
+import com.viaversion.viaversion.exception.CancelException;
+import com.viaversion.viaversion.exception.InformativeException;
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelFuture;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.UUID;
+import java.util.function.Function;
+
+public interface UserConnection {
+
+    /**
+     * Get an object from the storage.
+     *
+     * @param objectClass The class of the object to get
+     * @param <T>         The type of the class you want to get.
+     * @return The requested object
+     */
+    @Nullable <T extends StorableObject> T get(Class<T> objectClass);
+
+    /**
+     * Check if the storage has an object.
+     *
+     * @param objectClass The object class to check
+     * @return True if the object is in the storage
+     */
+    boolean has(Class<? extends StorableObject> objectClass);
+
+    /**
+     * Put an object into the stored objects based on class.
+     *
+     * @param object The object to store.
+     */
+    void put(StorableObject object);
+
+    /**
+     * Returns a collection of entity trackers currently registered.
+     *
+     * @return collection of entity trackers currently registered
+     */
+    Collection<EntityTracker> getEntityTrackers();
+
+    /**
+     * Returns the entity tracker by the given protocol class if present.
+     *
+     * @param protocolClass protocol class
+     * @param <T>           entity tracker type
+     * @return entity tracker if present
+     */
+    @Nullable <T extends EntityTracker> T getEntityTracker(Class<? extends Protocol> protocolClass);
+
+    /**
+     * Adds an entity tracker to the user connection.
+     *
+     * @param protocolClass protocol class
+     * @param tracker       entity tracker
+     */
+    void addEntityTracker(Class<? extends Protocol> protocolClass, EntityTracker tracker);
+
+    /**
+     * Clear all the stored objects.
+     * Used for bungee when switching servers.
+     */
+    void clearStoredObjects();
+
+    /**
+     * Sends a raw packet to the connection on the current thread.
+     *
+     * @param packet raw packet to send
+     */
+    void sendRawPacket(ByteBuf packet);
+
+    /**
+     * Send a raw packet to the player, submitted to the netty event loop.
+     *
+     * @param packet raw packet to send
+     */
+    void scheduleSendRawPacket(ByteBuf packet);
+
+    /**
+     * Send a raw packet to the player with returning the future.
+     *
+     * @param packet The raw packet to send
+     * @return ChannelFuture of the packet being sent
+     */
+    ChannelFuture sendRawPacketFuture(ByteBuf packet);
+
+    /**
+     * Returns the user's packet tracker used for the inbuilt packet-limiter.
+     *
+     * @return packet tracker
+     */
+    PacketTracker getPacketTracker();
+
+    /**
+     * Disconnect a connection.
+     *
+     * @param reason The reason to use, not used if player is not active.
+     */
+    void disconnect(String reason);
+
+    /**
+     * Sends a raw packet to the server on the current thread.
+     *
+     * @param packet raw packet to be sent
+     */
+    void sendRawPacketToServer(ByteBuf packet);
+
+    /**
+     * Sends a raw packet to the server, submitted to the netty event loop.
+     *
+     * @param packet raw packet to be sent
+     */
+    void scheduleSendRawPacketToServer(ByteBuf packet);
+
+    /**
+     * Monitors serverbound packets and returns whether a packet can/should be processed.
+     *
+     * @return false if this packet should be cancelled
+     */
+    boolean checkServerboundPacket();
+
+    /**
+     * Monitors clientbound packets and returns whether a packet can/should be processed.
+     *
+     * @return false if this packet should be cancelled
+     */
+    boolean checkClientboundPacket();
+
+    /**
+     * @see #checkClientboundPacket()
+     * @see #checkServerboundPacket()
+     */
+    default boolean checkIncomingPacket() {
+        return isClientSide() ? checkClientboundPacket() : checkServerboundPacket();
+    }
+
+    /**
+     * @see #checkClientboundPacket()
+     * @see #checkServerboundPacket()
+     */
+    default boolean checkOutgoingPacket() {
+        return isClientSide() ? checkServerboundPacket() : checkClientboundPacket();
+    }
+
+    /**
+     * Checks if packets needs transforming.
+     *
+     * @return whether packets should be passed through
+     */
+    boolean shouldTransformPacket();
+
+    /**
+     * Transforms the clientbound packet contained in ByteBuf.
+     *
+     * @param buf            ByteBuf with packet id and packet contents
+     * @param cancelSupplier function called with original CancelException for generating the Exception when the packet is cancelled
+     * @throws CancelException      if the packet should be cancelled
+     * @throws InformativeException if packet transforming failed
+     * @throws Exception            if any other processing outside of transforming fails
+     */
+    void transformClientbound(ByteBuf buf, Function<Throwable, Exception> cancelSupplier) throws Exception;
+
+    /**
+     * Transforms the serverbound packet contained in ByteBuf.
+     *
+     * @param buf            ByteBuf with packet id and packet contents
+     * @param cancelSupplier Function called with original CancelException for generating the Exception used when
+     *                       packet is cancelled
+     * @throws CancelException      if the packet should be cancelled
+     * @throws InformativeException if packet transforming failed
+     * @throws Exception            if any other processing outside of transforming fails
+     */
+    void transformServerbound(ByteBuf buf, Function<Throwable, Exception> cancelSupplier) throws Exception;
+
+    /**
+     * Transforms the packet depending on whether the connection is clientside or not.
+     *
+     * @see #transformClientbound(ByteBuf, Function)
+     * @see #transformServerbound(ByteBuf, Function)
+     */
+    default void transformOutgoing(ByteBuf buf, Function<Throwable, Exception> cancelSupplier) throws Exception {
+        if (isClientSide()) {
+            transformServerbound(buf, cancelSupplier);
+        } else {
+            transformClientbound(buf, cancelSupplier);
+        }
+    }
+
+    /**
+     * Transforms the packet depending on whether the connection is clientside or not.
+     *
+     * @see #transformClientbound(ByteBuf, Function)
+     * @see #transformServerbound(ByteBuf, Function)
+     */
+    default void transformIncoming(ByteBuf buf, Function<Throwable, Exception> cancelSupplier) throws Exception {
+        if (isClientSide()) {
+            transformClientbound(buf, cancelSupplier);
+        } else {
+            transformServerbound(buf, cancelSupplier);
+        }
+    }
+
+    /**
+     * Returns the internal id incremented for each new connection.
+     *
+     * @return internal id
+     */
+    long getId();
+
+    /**
+     * Returns the netty channel if present.
+     *
+     * @return netty channel if present
+     */
+    @Nullable Channel getChannel();
+
+    /**
+     * Returns info containing the current protocol state and userdata.
+     *
+     * @return info containing the current protocol state and userdata
+     */
+    ProtocolInfo getProtocolInfo();
+
+    /**
+     * Returns a map of stored objects.
+     *
+     * @return map of stored objects
+     * @see #has(Class)
+     * @see #get(Class)
+     * @see #put(StorableObject)
+     */
+    Map<Class<?>, StorableObject> getStoredObjects();
+
+    /**
+     * Returns whether the connection has protocols other than the base protocol applied.
+     *
+     * @return whether the connection is active
+     */
+    boolean isActive();
+
+    void setActive(boolean active);
+
+    /**
+     * Returns whether the connection is pending a disconnect, initiated through {@link #disconnect(String)}.
+     *
+     * @return whether the connection is pending a disconnect
+     */
+    boolean isPendingDisconnect();
+
+    void setPendingDisconnect(boolean pendingDisconnect);
+
+    /**
+     * Returns whether this is a client-side connection.
+     * This is a mod integrated into the client itself, or for example a backend Velocity connection.
+     *
+     * @return whether this is a client-side connection
+     */
+    boolean isClientSide();
+
+    /**
+     * Returns whether {@link ViaVersionConfig#getBlockedProtocols()} should be checked for this connection.
+     *
+     * @return whether blocked protocols should be applied
+     */
+    boolean shouldApplyBlockProtocol();
+
+    /**
+     * Returns a newly generated uuid that will let a packet be passed through without
+     * transformig its contents if used together with {@link PacketWrapper#PASSTHROUGH_ID}.
+     *
+     * @return generated passthrough token
+     */
+    UUID generatePassthroughToken();
+}

api/src/main/java/com/viaversion/viaversion/api/data/IntArrayMappings.java

@@ -0,0 +1,122 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.data;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.Arrays;
+
+public class IntArrayMappings implements Mappings {
+    protected final int[] oldToNew;
+
+    public IntArrayMappings(int[] oldToNew) {
+        this.oldToNew = oldToNew;
+    }
+
+    /**
+     * Maps old identifiers to the new ones.
+     * If an old value cannot be found in the new mappings, the diffmapping will be checked for the given entry.
+     *
+     * @param size        set size of the underlying short array
+     * @param oldMapping  mappings to map from
+     * @param newMapping  mappings to map to
+     * @param diffMapping extra mappings that will be used/scanned when an entry cannot be found
+     */
+    public IntArrayMappings(int size, JsonObject oldMapping, JsonObject newMapping, @Nullable JsonObject diffMapping) {
+        oldToNew = new int[size];
+        Arrays.fill(oldToNew, -1);
+        MappingDataLoader.mapIdentifiers(oldToNew, oldMapping, newMapping, diffMapping);
+    }
+
+    public IntArrayMappings(JsonObject oldMapping, JsonObject newMapping, @Nullable JsonObject diffMapping) {
+        this(oldMapping.entrySet().size(), oldMapping, newMapping, diffMapping);
+    }
+
+    /**
+     * Maps old identifiers to the new ones.
+     *
+     * @param size       set size of the underlying short array
+     * @param oldMapping mappings to map from
+     * @param newMapping mappings to map to
+     */
+    public IntArrayMappings(int size, JsonObject oldMapping, JsonObject newMapping) {
+        oldToNew = new int[size];
+        Arrays.fill(oldToNew, -1);
+        MappingDataLoader.mapIdentifiers(oldToNew, oldMapping, newMapping);
+    }
+
+    public IntArrayMappings(JsonObject oldMapping, JsonObject newMapping) {
+        this(oldMapping.entrySet().size(), oldMapping, newMapping);
+    }
+
+    /**
+     * Maps old identifiers to the new ones.
+     *
+     * @param size          set size of the underlying short array
+     * @param oldMapping    mappings to map from
+     * @param newMapping    mappings to map to
+     * @param diffMapping   extra mappings that will be used/scanned when an entry cannot be found
+     * @param warnOnMissing should "No key for x" be printed if there is no matching identifier
+     */
+    public IntArrayMappings(int size, JsonArray oldMapping, JsonArray newMapping, JsonObject diffMapping, boolean warnOnMissing) {
+        oldToNew = new int[size];
+        Arrays.fill(oldToNew, -1);
+        MappingDataLoader.mapIdentifiers(oldToNew, oldMapping, newMapping, diffMapping, warnOnMissing);
+    }
+
+    public IntArrayMappings(int size, JsonArray oldMapping, JsonArray newMapping, boolean warnOnMissing) {
+        this(size, oldMapping, newMapping, null, warnOnMissing);
+    }
+
+    public IntArrayMappings(JsonArray oldMapping, JsonArray newMapping, boolean warnOnMissing) {
+        this(oldMapping.size(), oldMapping, newMapping, warnOnMissing);
+    }
+
+    public IntArrayMappings(int size, JsonArray oldMapping, JsonArray newMapping) {
+        this(size, oldMapping, newMapping, true);
+    }
+
+    public IntArrayMappings(JsonArray oldMapping, JsonArray newMapping, JsonObject diffMapping) {
+        this(oldMapping.size(), oldMapping, newMapping, diffMapping, true);
+    }
+
+    public IntArrayMappings(JsonArray oldMapping, JsonArray newMapping) {
+        this(oldMapping.size(), oldMapping, newMapping, true);
+    }
+
+    @Override
+    public int getNewId(int id) {
+        return id >= 0 && id < oldToNew.length ? oldToNew[id] : -1;
+    }
+
+    @Override
+    public void setNewId(int id, int newId) {
+        oldToNew[id] = newId;
+    }
+
+    public int[] getOldToNew() {
+        return oldToNew;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/data/MappingData.java

@@ -0,0 +1,103 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.data;
+
+import com.viaversion.viaversion.api.minecraft.RegistryType;
+import com.viaversion.viaversion.api.minecraft.TagData;
+import com.viaversion.viaversion.util.Int2IntBiMap;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.List;
+
+public interface MappingData {
+
+    /**
+     * Loads the mapping data.
+     */
+    void load();
+
+    /**
+     * Returns the mapped block state id, or -1 if unmapped.
+     *
+     * @param id unmapped block state id
+     * @return mapped block state id, or -1 if unmapped
+     * @throws NullPointerException if this mappingdata does not hold block state mappings
+     */
+    int getNewBlockStateId(int id);
+
+    /**
+     * Returns the mapped block id, or -1 if unmapped.
+     *
+     * @param id unmapped block id
+     * @return mapped block id, or -1 if unmapped
+     * @throws NullPointerException if this mappingdata does not hold block mappings
+     */
+    int getNewBlockId(int id);
+
+    /**
+     * Returns the mapped item id, or -1 if unmapped.
+     *
+     * @param id unmapped item id
+     * @return mapped item id, or -1 if unmapped
+     * @throws NullPointerException if this mappingdata does not hold item mappings
+     */
+    int getNewItemId(int id);
+
+    /**
+     * Returns the backwards mapped item id, or -1 if unmapped.
+     *
+     * @param id mapped item id
+     * @return backwards mapped item id, or -1 if unmapped
+     * @throws NullPointerException if this mappingdata does not hold item mappings
+     */
+    int getOldItemId(int id);
+
+    /**
+     * Returns the mapped particle id, or -1 if unmapped.
+     *
+     * @param id unmapped particle id
+     * @return mapped particle id, or -1 if unmapped
+     * @throws NullPointerException if this mappingdata does not hold particle mappings
+     */
+    int getNewParticleId(int id);
+
+    /**
+     * Returns a list of tags to send if present.
+     *
+     * @param type registry tag type
+     * @return list of tags to send if present, else null
+     */
+    @Nullable List<TagData> getTags(RegistryType type);
+
+    @Nullable Int2IntBiMap getItemMappings();
+
+    @Nullable ParticleMappings getParticleMappings();
+
+    @Nullable Mappings getBlockMappings();
+
+    @Nullable Mappings getBlockStateMappings();
+
+    @Nullable Mappings getSoundMappings();
+
+    @Nullable Mappings getStatisticsMappings();
+}

api/src/main/java/com/viaversion/viaversion/api/data/MappingDataBase.java

@@ -0,0 +1,234 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.data;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.viaversion.viaversion.api.Via;
+import com.viaversion.viaversion.api.minecraft.RegistryType;
+import com.viaversion.viaversion.api.minecraft.TagData;
+import com.viaversion.viaversion.util.Int2IntBiHashMap;
+import com.viaversion.viaversion.util.Int2IntBiMap;
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.ArrayList;
+import java.util.EnumMap;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Logger;
+
+public class MappingDataBase implements MappingData {
+    protected final String oldVersion;
+    protected final String newVersion;
+    protected final boolean hasDiffFile;
+    protected Int2IntBiMap itemMappings;
+    protected ParticleMappings particleMappings;
+    protected Mappings blockMappings;
+    protected Mappings blockStateMappings;
+    protected Mappings soundMappings;
+    protected Mappings statisticsMappings;
+    protected Map<RegistryType, List<TagData>> tags;
+    protected boolean loadItems = true;
+
+    public MappingDataBase(String oldVersion, String newVersion) {
+        this(oldVersion, newVersion, false);
+    }
+
+    public MappingDataBase(String oldVersion, String newVersion, boolean hasDiffFile) {
+        this.oldVersion = oldVersion;
+        this.newVersion = newVersion;
+        this.hasDiffFile = hasDiffFile;
+    }
+
+    @Override
+    public void load() {
+        getLogger().info("Loading " + oldVersion + " -> " + newVersion + " mappings...");
+        JsonObject diffmapping = hasDiffFile ? loadDiffFile() : null;
+        JsonObject oldMappings = MappingDataLoader.loadData("mapping-" + oldVersion + ".json", true);
+        JsonObject newMappings = MappingDataLoader.loadData("mapping-" + newVersion + ".json", true);
+
+        blockMappings = loadFromObject(oldMappings, newMappings, diffmapping, "blocks");
+        blockStateMappings = loadFromObject(oldMappings, newMappings, diffmapping, "blockstates");
+        soundMappings = loadFromArray(oldMappings, newMappings, diffmapping, "sounds");
+        statisticsMappings = loadFromArray(oldMappings, newMappings, diffmapping, "statistics");
+
+        Mappings particles = loadFromArray(oldMappings, newMappings, diffmapping, "particles");
+        if (particles != null) {
+            particleMappings = new ParticleMappings(oldMappings.getAsJsonArray("particles"), particles);
+        }
+
+        if (loadItems && newMappings.has("items")) {
+            itemMappings = new Int2IntBiHashMap();
+            itemMappings.defaultReturnValue(-1);
+            MappingDataLoader.mapIdentifiers(itemMappings, oldMappings.getAsJsonObject("items"), newMappings.getAsJsonObject("items"),
+                    diffmapping != null ? diffmapping.getAsJsonObject("items") : null);
+        }
+
+        if (diffmapping != null && diffmapping.has("tags")) {
+            this.tags = new EnumMap<>(RegistryType.class);
+            JsonObject tags = diffmapping.getAsJsonObject("tags");
+            if (tags.has(RegistryType.ITEM.getResourceLocation())) {
+                loadTags(RegistryType.ITEM, tags, MappingDataLoader.indexedObjectToMap(newMappings.getAsJsonObject("items")));
+            }
+            if (tags.has(RegistryType.BLOCK.getResourceLocation())) {
+                loadTags(RegistryType.BLOCK, tags, MappingDataLoader.indexedObjectToMap(newMappings.getAsJsonObject("blocks")));
+            }
+        }
+
+        loadExtras(oldMappings, newMappings, diffmapping);
+    }
+
+    private void loadTags(RegistryType type, JsonObject object, Object2IntMap<String> typeMapping) {
+        JsonObject tags = object.getAsJsonObject(type.getResourceLocation());
+        List<TagData> tagsList = new ArrayList<>(tags.size());
+        for (Map.Entry<String, JsonElement> entry : tags.entrySet()) {
+            JsonArray array = entry.getValue().getAsJsonArray();
+            int[] entries = new int[array.size()];
+            int i = 0;
+            for (JsonElement element : array) {
+                String stringId = element.getAsString();
+                if (!typeMapping.containsKey(stringId) && !typeMapping.containsKey(stringId = stringId.replace("minecraft:", ""))) { // aaa
+                    getLogger().warning(type + " Tags contains invalid type identifier " + stringId + " in tag " + entry.getKey());
+                    continue;
+                }
+
+                entries[i++] = typeMapping.getInt(stringId);
+            }
+            tagsList.add(new TagData(entry.getKey(), entries));
+        }
+
+        this.tags.put(type, tagsList);
+    }
+
+    @Override
+    public int getNewBlockStateId(int id) {
+        return checkValidity(id, blockStateMappings.getNewId(id), "blockstate");
+    }
+
+    @Override
+    public int getNewBlockId(int id) {
+        return checkValidity(id, blockMappings.getNewId(id), "block");
+    }
+
+    @Override
+    public int getNewItemId(int id) {
+        return checkValidity(id, itemMappings.get(id), "item");
+    }
+
+    @Override
+    public int getOldItemId(int id) {
+        int oldId = itemMappings.inverse().get(id);
+        // Remap new items to stone
+        return oldId != -1 ? oldId : 1;
+    }
+
+    @Override
+    public int getNewParticleId(int id) {
+        return checkValidity(id, particleMappings.getMappings().getNewId(id), "particles");
+    }
+
+    @Override
+    public @Nullable List<TagData> getTags(RegistryType type) {
+        return tags != null ? tags.get(type) : null;
+    }
+
+    @Override
+    public @Nullable Int2IntBiMap getItemMappings() {
+        return itemMappings;
+    }
+
+    @Override
+    public @Nullable ParticleMappings getParticleMappings() {
+        return particleMappings;
+    }
+
+    @Override
+    public @Nullable Mappings getBlockMappings() {
+        return blockMappings;
+    }
+
+    @Override
+    public @Nullable Mappings getBlockStateMappings() {
+        return blockStateMappings;
+    }
+
+    @Override
+    public @Nullable Mappings getSoundMappings() {
+        return soundMappings;
+    }
+
+    @Override
+    public @Nullable Mappings getStatisticsMappings() {
+        return statisticsMappings;
+    }
+
+    protected @Nullable Mappings loadFromArray(JsonObject oldMappings, JsonObject newMappings, @Nullable JsonObject diffMappings, String key) {
+        if (!oldMappings.has(key) || !newMappings.has(key)) return null;
+
+        JsonObject diff = diffMappings != null ? diffMappings.getAsJsonObject(key) : null;
+        return new IntArrayMappings(oldMappings.getAsJsonArray(key), newMappings.getAsJsonArray(key), diff);
+    }
+
+    protected @Nullable Mappings loadFromObject(JsonObject oldMappings, JsonObject newMappings, @Nullable JsonObject diffMappings, String key) {
+        if (!oldMappings.has(key) || !newMappings.has(key)) return null;
+
+        JsonObject diff = diffMappings != null ? diffMappings.getAsJsonObject(key) : null;
+        return new IntArrayMappings(oldMappings.getAsJsonObject(key), newMappings.getAsJsonObject(key), diff);
+    }
+
+    protected @Nullable JsonObject loadDiffFile() {
+        return MappingDataLoader.loadData("mappingdiff-" + oldVersion + "to" + newVersion + ".json");
+    }
+
+    protected Logger getLogger() {
+        return Via.getPlatform().getLogger();
+    }
+
+    /**
+     * Returns the given mapped id if valid, else 0 with a warning logged to the console.
+     *
+     * @param id       unmapped id
+     * @param mappedId mapped id
+     * @param type     mapping type (e.g. "item")
+     * @return the given mapped id if valid, else 0
+     */
+    protected int checkValidity(int id, int mappedId, String type) {
+        if (mappedId == -1) {
+            getLogger().warning(String.format("Missing %s %s for %s %s %d", newVersion, type, oldVersion, type, id));
+            return 0;
+        }
+        return mappedId;
+    }
+
+    /**
+     * To be overridden.
+     *
+     * @param oldMappings  old mappings
+     * @param newMappings  new mappings
+     * @param diffMappings diff mappings if present
+     */
+    protected void loadExtras(JsonObject oldMappings, JsonObject newMappings, @Nullable JsonObject diffMappings) {
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/data/MappingDataLoader.java

@@ -1,16 +1,38 @@
-package us.myles.ViaVersion.api.data;
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.data;
 
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonIOException;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonSyntaxException;
+import com.viaversion.viaversion.api.Via;
+import com.viaversion.viaversion.util.GsonUtil;
+import com.viaversion.viaversion.util.Int2IntBiMap;
 import it.unimi.dsi.fastutil.objects.Object2IntMap;
 import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
-import org.jetbrains.annotations.Nullable;
-import us.myles.ViaVersion.api.Via;
-import us.myles.ViaVersion.util.GsonUtil;
-import us.myles.ViaVersion.util.Int2IntBiMap;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.io.File;
 import java.io.FileReader;
@@ -40,8 +62,9 @@ public class MappingDataLoader {
     }
 
     /**
-     * Returns the cached mappings. Cleared after Via has been fully loaded.
+     * Returns the cached mappings. Cleared after ViaVersion has been fully loaded.
      *
+     * @return cached mapping file json objects
      * @see #isCacheJsonMappings()
      */
     public static Map<String, JsonObject> getMappingsCache() {
@@ -50,9 +73,10 @@ public class MappingDataLoader {
 
     /**
      * Loads the file from the plugin folder if present, else from the bundled resources.
+     *
+     * @return loaded json object, or null if not found or invalid
      */
-    @Nullable
-    public static JsonObject loadFromDataDir(String name) {
+    public static @Nullable JsonObject loadFromDataDir(String name) {
         File file = new File(Via.getPlatform().getDataFolder(), name);
         if (!file.exists()) return loadData(name);
 
@@ -71,9 +95,10 @@ public class MappingDataLoader {
 
     /**
      * Loads the file from the bundled resources. Uses the cache if enabled.
+     *
+     * @return loaded json object from bundled resources if present
      */
-    @Nullable
-    public static JsonObject loadData(String name) {
+    public static @Nullable JsonObject loadData(String name) {
         return loadData(name, false);
     }
 
@@ -81,9 +106,9 @@ public class MappingDataLoader {
      * Loads the file from the bundled resources. Uses the cache if enabled.
      *
      * @param cacheIfEnabled whether loaded files should be cached
+     * @return loaded json object from bundled resources if present
      */
-    @Nullable
-    public static JsonObject loadData(String name, boolean cacheIfEnabled) {
+    public static @Nullable JsonObject loadData(String name, boolean cacheIfEnabled) {
         if (cacheJsonMappings) {
             JsonObject cached = MAPPINGS_CACHE.get(name);
             if (cached != null) {
@@ -120,16 +145,16 @@ public class MappingDataLoader {
         }
     }
 
-    public static void mapIdentifiers(short[] output, JsonObject oldIdentifiers, JsonObject newIdentifiers) {
+    public static void mapIdentifiers(int[] output, JsonObject oldIdentifiers, JsonObject newIdentifiers) {
         MappingDataLoader.mapIdentifiers(output, oldIdentifiers, newIdentifiers, null);
     }
 
-    public static void mapIdentifiers(short[] output, JsonObject oldIdentifiers, JsonObject newIdentifiers, @Nullable JsonObject diffIdentifiers) {
-        Object2IntMap newIdentifierMap = MappingDataLoader.indexedObjectToMap(newIdentifiers);
+    public static void mapIdentifiers(int[] output, JsonObject oldIdentifiers, JsonObject newIdentifiers, @Nullable JsonObject diffIdentifiers) {
+        Object2IntMap<String> newIdentifierMap = MappingDataLoader.indexedObjectToMap(newIdentifiers);
         for (Map.Entry<String, JsonElement> entry : oldIdentifiers.entrySet()) {
             int value = mapIdentifierEntry(entry, newIdentifierMap, diffIdentifiers);
             if (value != -1) {
-                output[Integer.parseInt(entry.getKey())] = (short) value;
+                output[Integer.parseInt(entry.getKey())] = value;
             }
         }
     }
@@ -154,11 +179,11 @@ public class MappingDataLoader {
         return value;
     }
 
-    public static void mapIdentifiers(short[] output, JsonArray oldIdentifiers, JsonArray newIdentifiers, boolean warnOnMissing) {
+    public static void mapIdentifiers(int[] output, JsonArray oldIdentifiers, JsonArray newIdentifiers, boolean warnOnMissing) {
         mapIdentifiers(output, oldIdentifiers, newIdentifiers, null, warnOnMissing);
     }
 
-    public static void mapIdentifiers(short[] output, JsonArray oldIdentifiers, JsonArray newIdentifiers, @Nullable JsonObject diffIdentifiers, boolean warnOnMissing) {
+    public static void mapIdentifiers(int[] output, JsonArray oldIdentifiers, JsonArray newIdentifiers, @Nullable JsonObject diffIdentifiers, boolean warnOnMissing) {
         Object2IntMap<String> newIdentifierMap = MappingDataLoader.arrayToMap(newIdentifiers);
         for (int i = 0; i < oldIdentifiers.size(); i++) {
             JsonElement oldIdentifier = oldIdentifiers.get(i);
@@ -181,11 +206,13 @@ public class MappingDataLoader {
                     continue;
                 }
             }
-            output[i] = (short) mappedId;
+            output[i] = mappedId;
         }
     }
 
     /**
+     * Returns a map of the object entries hashed by their id value.
+     *
      * @param object json object
      * @return map with indexes hashed by their id value
      */
@@ -199,6 +226,8 @@ public class MappingDataLoader {
     }
 
     /**
+     * Returns a map of the array entries hashed by their id value.
+     *
      * @param array json array
      * @return map with indexes hashed by their id value
      */
@@ -211,8 +240,7 @@ public class MappingDataLoader {
         return map;
     }
 
-    @Nullable
-    public static InputStream getResource(String name) {
+    public static @Nullable InputStream getResource(String name) {
         return MappingDataLoader.class.getClassLoader().getResourceAsStream("assets/viaversion/data/" + name);
     }
 }

api/src/main/java/com/viaversion/viaversion/api/data/Mappings.java

@@ -0,0 +1,43 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.data;
+
+public interface Mappings {
+
+    /**
+     * Returns the mapped id from the given id, or -1 if invalid/out of bounds.
+     *
+     * @param id unmapped id
+     * @return mapped id, or -1 if invalid/out of bounds
+     */
+    int getNewId(int id);
+
+    /**
+     * Manually maps a specific id.
+     *
+     * @param id    unmapped id
+     * @param newId mapped id
+     * @throws IndexOutOfBoundsException if the unmapped id is invalid
+     */
+    void setNewId(int id, int newId);
+}

api/src/main/java/com/viaversion/viaversion/api/data/ParticleMappings.java

@@ -0,0 +1,58 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.data;
+
+import com.google.gson.JsonArray;
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+
+public class ParticleMappings {
+    private final Mappings mappings;
+    private final int blockId;
+    private final int fallingDustId;
+    private final int itemId;
+
+    public ParticleMappings(JsonArray oldMappings, Mappings mappings) {
+        this.mappings = mappings;
+
+        Object2IntMap<String> map = MappingDataLoader.arrayToMap(oldMappings);
+        blockId = map.getInt("block");
+        fallingDustId = map.getInt("falling_dust");
+        itemId = map.getInt("item");
+    }
+
+    public Mappings getMappings() {
+        return mappings;
+    }
+
+    public int getBlockId() {
+        return blockId;
+    }
+
+    public int getFallingDustId() {
+        return fallingDustId;
+    }
+
+    public int getItemId() {
+        return itemId;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/data/entity/ClientEntityIdChangeListener.java

@@ -0,0 +1,28 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.data.entity;
+
+public interface ClientEntityIdChangeListener {
+
+    void setClientEntityId(int entityId);
+}

api/src/main/java/com/viaversion/viaversion/api/data/entity/EntityTracker.java

@@ -0,0 +1,129 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.data.entity;
+
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.minecraft.entities.EntityType;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public interface EntityTracker {
+
+    /**
+     * User connection the tracker belongs to.
+     *
+     * @return user connection
+     */
+    UserConnection user();
+
+    /**
+     * Tracks an entity.
+     *
+     * @param id   entity id
+     * @param type entity type
+     */
+    void addEntity(int id, EntityType type);
+
+    /**
+     * Returns whether the entity is currently tracked.
+     *
+     * @param id entity id
+     * @return whether the entity is tracked
+     */
+    boolean hasEntity(int id);
+
+    /**
+     * Entity type of the entity if tracked.
+     * This returning null does not necessarily mean no entity by the id exists.
+     *
+     * @param id entity id
+     * @return entity type of the entity if tracked
+     */
+    @Nullable EntityType entityType(int id);
+
+    /**
+     * Untracks an entity.
+     *
+     * @param id entity id
+     */
+    void removeEntity(int id);
+
+    /**
+     * Returns the stored entity data if an entity with the id is tracked, else null.
+     * If no data has been initialized yet, it will be done and returned by this method.
+     *
+     * @param id entity id
+     * @return stored entity data if an entity with the id is tracked, else null
+     */
+    @Nullable StoredEntityData entityData(int id);
+
+    /**
+     * Returns stored entity data if it has previously been initialized by {@link #entityData(int)}, else null.
+     *
+     * @param id entity id
+     * @return stored entity data if it has previously been initialized by {@link #entityData(int)}
+     */
+    @Nullable StoredEntityData entityDataIfPresent(int id);
+
+    /**
+     * Returns the client entity id or -1 if unset.
+     *
+     * @return client entity id or -1 if unset
+     */
+    int clientEntityId();
+
+    /**
+     * Sets the client entity id.
+     *
+     * @param clientEntityId client entity id
+     */
+    void setClientEntityId(int clientEntityId);
+
+    /**
+     * Returns the current world section height.
+     * Always 16 for sub 1.17 worlds.
+     *
+     * @return current world section height
+     */
+    int currentWorldSectionHeight();
+
+    /**
+     * Sets the current world section height.
+     *
+     * @param currentWorldSectionHeight world section height
+     */
+    void setCurrentWorldSectionHeight(int currentWorldSectionHeight);
+
+    /**
+     * Returns the minimum y of the current player world.
+     *
+     * @return minimum y of the current world
+     */
+    int currentMinY();
+
+    /**
+     * Sets the minimum y of the current player world.
+     *
+     * @param currentMinY minimum y of the current world
+     */
+    void setCurrentMinY(int currentMinY);
+}

api/src/main/java/com/viaversion/viaversion/api/data/entity/StoredEntityData.java

@@ -0,0 +1,60 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.data.entity;
+
+import com.viaversion.viaversion.api.minecraft.entities.EntityType;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public interface StoredEntityData {
+
+    /**
+     * Returns the entity type of the stored entity.
+     *
+     * @return entity type
+     */
+    EntityType type();
+
+    /**
+     * Checks if the storage contains an object of the given type.
+     *
+     * @param objectClass object class to check
+     * @return whether an object of the given type is in the storage
+     */
+    boolean has(Class<?> objectClass);
+
+    /**
+     * Returns an object from the storage if present.
+     *
+     * @param objectClass class of the object to get
+     * @param <T>         object type
+     * @return object if present
+     */
+    @Nullable <T> T get(Class<T> objectClass);
+
+    /**
+     * Stores an object based on its class.
+     *
+     * @param object object to store
+     */
+    void put(Object object);
+}

api/src/main/java/com/viaversion/viaversion/api/legacy/LegacyViaAPI.java

@@ -0,0 +1,58 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.legacy;
+
+import com.viaversion.viaversion.api.legacy.bossbar.BossBar;
+import com.viaversion.viaversion.api.legacy.bossbar.BossColor;
+import com.viaversion.viaversion.api.legacy.bossbar.BossStyle;
+
+/**
+ * API only applicable on or to legacy versions of Minecraft.
+ *
+ * @param <T> player type
+ */
+public interface LegacyViaAPI<T> {
+
+    /**
+     * Creates a new bossbar instance. This only works on pre 1.9 servers for 1.9+ clients.
+     *
+     * @param title  title
+     * @param health health, between 0 and 1 (inclusive)
+     * @param color  color
+     * @param style  style
+     * @return new bossbar instance
+     */
+    BossBar createLegacyBossBar(String title, float health, BossColor color, BossStyle style);
+
+    /**
+     * Creates a new bossbar instance with full health. This only works on pre 1.9 servers for 1.9+ clients.
+     *
+     * @param title title
+     * @param color color
+     * @param style style
+     * @return new bossbar instance
+     */
+    default BossBar createLegacyBossBar(String title, BossColor color, BossStyle style) {
+        return createLegacyBossBar(title, 1F, color, style);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/legacy/bossbar/BossBar.java

@@ -1,19 +1,40 @@
-package us.myles.ViaVersion.api.boss;
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.legacy.bossbar;
 
-import us.myles.ViaVersion.api.Via;
-import us.myles.ViaVersion.api.data.UserConnection;
+import com.viaversion.viaversion.api.connection.UserConnection;
 
 import java.util.Set;
 import java.util.UUID;
 
-public abstract class BossBar<T> {
+public interface BossBar {
 
     /**
      * Get the current title
      *
      * @return the title
      */
-    public abstract String getTitle();
+    String getTitle();
 
     /**
      * Change the title
@@ -21,14 +42,14 @@ public abstract class BossBar<T> {
      * @param title Title can be in either JSON or just text
      * @return The BossBar object
      */
-    public abstract BossBar setTitle(String title);
+    BossBar setTitle(String title);
 
     /**
      * Get the health
      *
      * @return float between 0F - 1F
      */
-    public abstract float getHealth();
+    float getHealth();
 
     /**
      * Change the health
@@ -36,14 +57,14 @@ public abstract class BossBar<T> {
      * @param health this float has to be between 0F - 1F
      * @return The BossBar object
      */
-    public abstract BossBar setHealth(float health);
+    BossBar setHealth(float health);
 
     /**
      * Get the bossbar color
      *
      * @return The colour
      */
-    public abstract BossColor getColor();
+    BossColor getColor();
 
     /**
      * Yay colors!
@@ -51,14 +72,14 @@ public abstract class BossBar<T> {
      * @param color Whatever color you want!
      * @return The BossBar object
      */
-    public abstract BossBar setColor(BossColor color);
+    BossBar setColor(BossColor color);
 
     /**
      * Get the bosbar style
      *
      * @return BossStyle
      */
-    public abstract BossStyle getStyle();
+    BossStyle getStyle();
 
     /**
      * Change the bosbar style
@@ -66,19 +87,7 @@ public abstract class BossBar<T> {
      * @param style BossStyle
      * @return The BossBar object
      */
-    public abstract BossBar setStyle(BossStyle style);
-
-    /**
-     * Show the bossbar to a player.
-     *
-     * @param player The player
-     * @return The BossBar object
-     * @deprecated Deprecated use UUID's instead of Player objects {@link #addPlayer(UUID)}
-     */
-    @Deprecated
-    public BossBar addPlayer(T player) {
-        throw new UnsupportedOperationException("This method is not implemented for the platform " + Via.getPlatform().getPlatformName());
-    }
+    BossBar setStyle(BossStyle style);
 
     /**
      * Show the bossbar to a player (uuid). This only works for frontend connections. Use #addConnection(UserConnection) for other types.
@@ -86,7 +95,7 @@ public abstract class BossBar<T> {
      * @param player uuid of the player
      * @return The BossBar object
      */
-    public abstract BossBar addPlayer(UUID player);
+    BossBar addPlayer(UUID player);
 
     /**
      * Show the bossbar to a player connection.
@@ -94,31 +103,7 @@ public abstract class BossBar<T> {
      * @param conn UserConnection of the connection
      * @return The BossBar object
      */
-    public abstract BossBar addConnection(UserConnection conn);
-
-    /**
-     * add multiple players
-     *
-     * @param players list of players
-     * @return The BossBar object
-     * @deprecated Deprecated use UUID's instead of Player objects {@link #addPlayer(UUID)}
-     */
-    @Deprecated
-    public BossBar addPlayers(T... players) {
-        throw new UnsupportedOperationException("This method is not implemented for the platform " + Via.getPlatform().getPlatformName());
-    }
-
-    /**
-     * Remove the bossbar from a player
-     *
-     * @param player The player
-     * @return The BossBar object
-     * @deprecated Deprecated use UUID's instead of Player objects {@link #removePlayer(UUID)}
-     */
-    @Deprecated
-    public BossBar removePlayer(T player) {
-        throw new UnsupportedOperationException("This method is not implemented for the platform " + Via.getPlatform().getPlatformName());
-    }
+    BossBar addConnection(UserConnection conn);
 
     /**
      * Removes the bossbar from a player. This only works for frontend connections. For others types, use #removeConnection(UserConnection)
@@ -126,7 +111,7 @@ public abstract class BossBar<T> {
      * @param uuid The players UUID
      * @return The BossBar object
      */
-    public abstract BossBar removePlayer(UUID uuid);
+    BossBar removePlayer(UUID uuid);
 
     /**
      * Removes the bossbar from a player connection.
@@ -134,7 +119,7 @@ public abstract class BossBar<T> {
      * @param conn The UserConnection
      * @return The BossBar object
      */
-    public abstract BossBar removeConnection(UserConnection conn);
+    BossBar removeConnection(UserConnection conn);
 
     /**
      * Add flags
@@ -142,7 +127,7 @@ public abstract class BossBar<T> {
      * @param flag The flag to add
      * @return The BossBar object
      */
-    public abstract BossBar addFlag(BossFlag flag);
+    BossBar addFlag(BossFlag flag);
 
     /**
      * Remove flags.
@@ -150,53 +135,53 @@ public abstract class BossBar<T> {
      * @param flag The flag to remove
      * @return The BossBar object
      */
-    public abstract BossBar removeFlag(BossFlag flag);
+    BossBar removeFlag(BossFlag flag);
 
     /**
      * @param flag The flag to check against
      * @return True if it has the flag
      */
-    public abstract boolean hasFlag(BossFlag flag);
+    boolean hasFlag(BossFlag flag);
 
     /**
      * Get players. Only returns UUIDs which are front-end. For all connections, use #getConnections()
      *
      * @return UUIDS from players (sorry I lied)
      */
-    public abstract Set<UUID> getPlayers();
+    Set<UUID> getPlayers();
 
     /**
      * Get UserConnections.
      *
      * @return UserConnection from players
      */
-    public abstract Set<UserConnection> getConnections();
+    Set<UserConnection> getConnections();
 
     /**
      * Show the bossbar to everyone (In the getPlayer set)
      *
      * @return The BossBar object
      */
-    public abstract BossBar show();
+    BossBar show();
 
     /**
      * Hide the bossbar from everyone (In the getPlayer set)
      *
      * @return The BossBar object
      */
-    public abstract BossBar hide();
+    BossBar hide();
 
     /**
      * Is it visible?
      *
      * @return visibility changable with show() and hide()
      */
-    public abstract boolean isVisible();
+    boolean isVisible();
 
     /**
      * Get the UUID of this bossbar
      *
      * @return Unique Id for this bossbar
      */
-    public abstract UUID getId();
+    UUID getId();
 }

api/src/main/java/com/viaversion/viaversion/api/legacy/bossbar/BossColor.java

@@ -0,0 +1,44 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.legacy.bossbar;
+
+public enum BossColor {
+
+    PINK(0),
+    BLUE(1),
+    RED(2),
+    GREEN(3),
+    YELLOW(4),
+    PURPLE(5),
+    WHITE(6);
+
+    private final int id;
+
+    BossColor(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+        return id;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/legacy/bossbar/BossFlag.java

@@ -0,0 +1,39 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.legacy.bossbar;
+
+public enum BossFlag {
+
+    DARKEN_SKY(1),
+    PLAY_BOSS_MUSIC(2);
+
+    private final int id;
+
+    BossFlag(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+        return id;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/legacy/bossbar/BossStyle.java

@@ -0,0 +1,42 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.legacy.bossbar;
+
+public enum BossStyle {
+
+    SOLID(0),
+    SEGMENTED_6(1),
+    SEGMENTED_10(2),
+    SEGMENTED_12(3),
+    SEGMENTED_20(4);
+
+    private final int id;
+
+    BossStyle(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+        return id;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/BlockChangeRecord.java

@@ -0,0 +1,68 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
+
+public interface BlockChangeRecord {
+
+    /**
+     * Returns the relative x coordinate within the chunk section.
+     *
+     * @return relative x coordinate within the chunk section
+     */
+    byte getSectionX();
+
+    /**
+     * Returns the relative y coordinate within the chunk section.
+     *
+     * @return relative y coordinate within the chunk section
+     */
+    byte getSectionY();
+
+    /**
+     * Returns the relative z coordinate within the chunk section.
+     *
+     * @return relative z coordinate within the chunk section
+     */
+    byte getSectionZ();
+
+    /**
+     * Returns the absolute y coordinate based on the given chunk section y.
+     *
+     * @param chunkSectionY chunk section
+     * @return absolute y coordinate
+     */
+    short getY(int chunkSectionY);
+
+    /**
+     * @return absolute y coordinate
+     * @deprecated 1.16+ stores the relative y coordinate
+     */
+    @Deprecated
+    default short getY() {
+        return getY(-1);
+    }
+
+    int getBlockId();
+
+    void setBlockId(int blockId);
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/BlockChangeRecord1_16_2.java

@@ -1,4 +1,26 @@
-package us.myles.ViaVersion.api.minecraft;
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
 
 import com.google.common.base.Preconditions;
 

api/src/main/java/com/viaversion/viaversion/api/minecraft/BlockChangeRecord1_8.java

@@ -0,0 +1,76 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
+
+public class BlockChangeRecord1_8 implements BlockChangeRecord {
+    private final byte sectionX;
+    private final short y;
+    private final byte sectionZ;
+    private int blockId;
+
+    public BlockChangeRecord1_8(byte sectionX, short y, byte sectionZ, int blockId) {
+        this.sectionX = sectionX;
+        this.y = y;
+        this.sectionZ = sectionZ;
+        this.blockId = blockId;
+    }
+
+    public BlockChangeRecord1_8(int sectionX, int y, int sectionZ, int blockId) {
+        this((byte) sectionX, (short) y, (byte) sectionZ, blockId);
+    }
+
+    /**
+     * @return x coordinate within the chunk section
+     */
+    public byte getSectionX() {
+        return sectionX;
+    }
+
+    @Override
+    public byte getSectionY() {
+        return (byte) (y & 0xF);
+    }
+
+    /**
+     * @return y coordinate
+     */
+    @Override
+    public short getY(int chunkSectionY) {
+        return y;
+    }
+
+    /**
+     * @return z coordinate within the chunk section
+     */
+    public byte getSectionZ() {
+        return sectionZ;
+    }
+
+    public int getBlockId() {
+        return blockId;
+    }
+
+    public void setBlockId(int blockId) {
+        this.blockId = blockId;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/BlockFace.java

@@ -1,4 +1,26 @@
-package us.myles.ViaVersion.api.minecraft;
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
 
 import java.util.HashMap;
 import java.util.Map;

api/src/main/java/com/viaversion/viaversion/api/minecraft/Environment.java

@@ -0,0 +1,52 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
+
+public enum Environment {
+
+    NORMAL(0),
+    NETHER(-1),
+    END(1);
+
+    private final int id;
+
+    Environment(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public static Environment getEnvironmentById(int id) {
+        switch (id) {
+            default:
+            case -1:
+                return NETHER;
+            case 0:
+                return NORMAL;
+            case 1:
+                return END;
+        }
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/EulerAngle.java

@@ -0,0 +1,47 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
+
+public class EulerAngle {
+    private final float x;
+    private final float y;
+    private final float z;
+
+    public EulerAngle(final float x, final float y, final float z) {
+        this.x = x;
+        this.y = y;
+        this.z = z;
+    }
+
+    public float getX() {
+        return x;
+    }
+
+    public float getY() {
+        return y;
+    }
+
+    public float getZ() {
+        return z;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/Position.java

@@ -0,0 +1,88 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
+
+public class Position {
+    private final int x;
+    private final int y;
+    private final int z;
+
+    public Position(int x, int y, int z) {
+        this.x = x;
+        this.y = y;
+        this.z = z;
+    }
+
+    public Position(int x, short y, int z) {
+        this.x = x;
+        this.y = y;
+        this.z = z;
+    }
+
+    public Position(Position toCopy) {
+        this(toCopy.getX(), toCopy.getY(), toCopy.getZ());
+    }
+
+    public Position getRelative(BlockFace face) {
+        return new Position(x + face.getModX(), (short) (y + face.getModY()), z + face.getModZ());
+    }
+
+    public int getX() {
+        return x;
+    }
+
+    public int getY() {
+        return y;
+    }
+
+    public int getZ() {
+        return z;
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Position position = (Position) o;
+        if (x != position.x) return false;
+        if (y != position.y) return false;
+        return z == position.z;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = x;
+        result = 31 * result + y;
+        result = 31 * result + z;
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "Position{" +
+                "x=" + x +
+                ", y=" + y +
+                ", z=" + z +
+                '}';
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/RegistryType.java

@@ -0,0 +1,64 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public enum RegistryType {
+
+    BLOCK("block"),
+    ITEM("item"),
+    FLUID("fluid"),
+    ENTITY("entity_type"),
+    GAME_EVENT("game_event");
+
+    private static final Map<String, RegistryType> MAP = new HashMap<>();
+    private static final RegistryType[] VALUES = values();
+
+    static {
+        for (RegistryType type : getValues()) {
+            MAP.put(type.resourceLocation, type);
+        }
+    }
+
+    public static RegistryType[] getValues() {
+        return VALUES;
+    }
+
+    public static @Nullable RegistryType getByKey(String resourceKey) {
+        return MAP.get(resourceKey);
+    }
+
+    private final String resourceLocation;
+
+    RegistryType(final String resourceLocation) {
+        this.resourceLocation = resourceLocation;
+    }
+
+    public String getResourceLocation() {
+        return resourceLocation;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/TagData.java

@@ -0,0 +1,41 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
+
+public final class TagData {
+    private final String identifier;
+    private final int[] entries;
+
+    public TagData(String identifier, int[] entries) {
+        this.identifier = identifier;
+        this.entries = entries;
+    }
+
+    public String identifier() {
+        return identifier;
+    }
+
+    public int[] entries() {
+        return entries;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/Vector.java

@@ -0,0 +1,59 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
+
+public class Vector {
+    private int blockX;
+    private int blockY;
+    private int blockZ;
+
+    public Vector(int blockX, int blockY, int blockZ) {
+        this.blockX = blockX;
+        this.blockY = blockY;
+        this.blockZ = blockZ;
+    }
+
+    public int getBlockX() {
+        return blockX;
+    }
+
+    public void setBlockX(int blockX) {
+        this.blockX = blockX;
+    }
+
+    public int getBlockY() {
+        return blockY;
+    }
+
+    public void setBlockY(int blockY) {
+        this.blockY = blockY;
+    }
+
+    public int getBlockZ() {
+        return blockZ;
+    }
+
+    public void setBlockZ(int blockZ) {
+        this.blockZ = blockZ;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/VillagerData.java

@@ -0,0 +1,47 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft;
+
+public class VillagerData {
+    private final int type;
+    private final int profession;
+    private final int level;
+
+    public VillagerData(final int type, final int profession, final int level) {
+        this.type = type;
+        this.profession = profession;
+        this.level = level;
+    }
+
+    public int getType() {
+        return type;
+    }
+
+    public int getProfession() {
+        return profession;
+    }
+
+    public int getLevel() {
+        return level;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/BaseChunk.java

@@ -0,0 +1,150 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.chunks;
+
+import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.BitSet;
+import java.util.List;
+
+//TODO Move methods from distinctly different versions to different objects/interfaces
+public class BaseChunk implements Chunk {
+    protected final int x;
+    protected final int z;
+    protected final boolean fullChunk;
+    protected boolean ignoreOldLightData;
+    protected BitSet chunkSectionBitSet;
+    protected int bitmask;
+    protected ChunkSection[] sections;
+    protected int[] biomeData;
+    protected CompoundTag heightMap;
+    protected final List<CompoundTag> blockEntities;
+
+    public BaseChunk(int x, int z, boolean fullChunk, boolean ignoreOldLightData, @Nullable BitSet chunkSectionBitSet,
+                     ChunkSection[] sections, int @Nullable [] biomeData, @Nullable CompoundTag heightMap, List<CompoundTag> blockEntities) {
+        this.x = x;
+        this.z = z;
+        this.fullChunk = fullChunk;
+        this.ignoreOldLightData = ignoreOldLightData;
+        this.chunkSectionBitSet = chunkSectionBitSet;
+        this.sections = sections;
+        this.biomeData = biomeData;
+        this.heightMap = heightMap;
+        this.blockEntities = blockEntities;
+    }
+
+    public BaseChunk(int x, int z, boolean fullChunk, boolean ignoreOldLightData, int bitmask, ChunkSection[] sections, int[] biomeData, CompoundTag heightMap, List<CompoundTag> blockEntities) {
+        this(x, z, fullChunk, ignoreOldLightData, null, sections, biomeData, heightMap, blockEntities);
+        this.bitmask = bitmask;
+    }
+
+    public BaseChunk(int x, int z, boolean fullChunk, boolean ignoreOldLightData, int bitmask, ChunkSection[] sections, int[] biomeData, List<CompoundTag> blockEntities) {
+        this(x, z, fullChunk, ignoreOldLightData, bitmask, sections, biomeData, null, blockEntities);
+    }
+
+    @Override
+    public boolean isBiomeData() {
+        return biomeData != null;
+    }
+
+    @Override
+    public int getX() {
+        return x;
+    }
+
+    @Override
+    public int getZ() {
+        return z;
+    }
+
+    @Override
+    public boolean isFullChunk() {
+        return fullChunk;
+    }
+
+    @Override
+    public boolean isIgnoreOldLightData() {
+        return ignoreOldLightData;
+    }
+
+    @Override
+    public void setIgnoreOldLightData(boolean ignoreOldLightData) {
+        this.ignoreOldLightData = ignoreOldLightData;
+    }
+
+    @Override
+    public int getBitmask() {
+        return bitmask;
+    }
+
+    @Override
+    public void setBitmask(int bitmask) {
+        this.bitmask = bitmask;
+    }
+
+    @Override
+    public @Nullable BitSet getChunkMask() {
+        return chunkSectionBitSet;
+    }
+
+    @Override
+    public void setChunkMask(BitSet chunkSectionMask) {
+        this.chunkSectionBitSet = chunkSectionMask;
+    }
+
+    @Override
+    public ChunkSection[] getSections() {
+        return sections;
+    }
+
+    @Override
+    public void setSections(ChunkSection[] sections) {
+        this.sections = sections;
+    }
+
+    @Override
+    public int @Nullable [] getBiomeData() {
+        return biomeData;
+    }
+
+    @Override
+    public void setBiomeData(int @Nullable [] biomeData) {
+        this.biomeData = biomeData;
+    }
+
+    @Override
+    public @Nullable CompoundTag getHeightMap() {
+        return heightMap;
+    }
+
+    @Override
+    public void setHeightMap(final CompoundTag heightMap) {
+        this.heightMap = heightMap;
+    }
+
+    @Override
+    public List<CompoundTag> getBlockEntities() {
+        return blockEntities;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/Chunk.java

@@ -0,0 +1,118 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.chunks;
+
+import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.BitSet;
+import java.util.List;
+
+public interface Chunk {
+
+    /**
+     * Returns the chunk x coordinate.
+     *
+     * @return chunk x coordinate
+     */
+    int getX();
+
+    /**
+     * Returns the chunk z coordinate.
+     *
+     * @return chunk z coordinate
+     */
+    int getZ();
+
+    /**
+     * Returns whether this chunk holds biome data, always true for 1.17+ chunks.
+     *
+     * @return true if this chunk holds biome data
+     */
+    boolean isBiomeData();
+
+    /**
+     * Returns whether this is a full chunk, always true for 1.17+ chunks.
+     *
+     * @return true if this is a full chunk
+     */
+    boolean isFullChunk();
+
+    boolean isIgnoreOldLightData();
+
+    void setIgnoreOldLightData(boolean ignoreOldLightData);
+
+    /**
+     * Returns the chunk section bit mask for chunks < 1.17.
+     *
+     * @return chunk section bit mask for chunks < 1.17
+     * @see #getChunkMask()
+     */
+    int getBitmask();
+
+    void setBitmask(int bitmask);
+
+    /**
+     * Returns the chunk section bit mask, only non-null for 1.17+ chunks.
+     *
+     * @return chunk section bit mask, only non-null for 1.17+ chunks
+     * @see #getBitmask()
+     */
+    @Nullable BitSet getChunkMask();
+
+    void setChunkMask(BitSet chunkSectionMask);
+
+    /**
+     * Returns an array of nullable chunk section entries.
+     *
+     * @return array of nullable chunk sections
+     */
+    @Nullable ChunkSection[] getSections();
+
+    void setSections(ChunkSection[] sections);
+
+    /**
+     * Returns the chunk's raw biome data. The format the biomes are stored may vary.
+     *
+     * @return raw biome data
+     */
+    int @Nullable [] getBiomeData();
+
+    void setBiomeData(int @Nullable [] biomeData);
+
+    /**
+     * Returns a compoundtag containing the chunk's heightmaps if present.
+     *
+     * @return compoundtag containing heightmaps if present
+     */
+    @Nullable CompoundTag getHeightMap();
+
+    void setHeightMap(@Nullable CompoundTag heightMap);
+
+    /**
+     * Returns a list of block entities.
+     *
+     * @return list of block entities
+     */
+    List<CompoundTag> getBlockEntities();
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/Chunk1_8.java

@@ -0,0 +1,60 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.chunks;
+
+import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Chunk1_8 extends BaseChunk {
+    private boolean unloadPacket;
+
+    public Chunk1_8(int x, int z, boolean groundUp, int bitmask, ChunkSection[] sections, int[] biomeData, List<CompoundTag> blockEntities) {
+        super(x, z, groundUp, false, bitmask, sections, biomeData, blockEntities);
+    }
+
+    /**
+     * Chunk unload.
+     *
+     * @param x coord
+     * @param z coord
+     */
+    public Chunk1_8(int x, int z) {
+        this(x, z, true, 0, new ChunkSection[16], null, new ArrayList<>());
+        this.unloadPacket = true;
+    }
+
+    /**
+     * Does this chunks have biome data
+     *
+     * @return True if the chunks has biome data
+     */
+    public boolean hasBiomeData() {
+        return biomeData != null && fullChunk;
+    }
+
+    public boolean isUnloadPacket() {
+        return unloadPacket;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/ChunkSection.java

@@ -0,0 +1,201 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.chunks;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public interface ChunkSection {
+
+    /**
+     * Size (dimensions) of blocks in a chunks section.
+     */
+    int SIZE = 16 * 16 * 16; // width * depth * height
+
+    /**
+     * Returns the block index of the given coordinates within a section.
+     *
+     * @param x section x
+     * @param y section y
+     * @param z section z
+     * @return section block index
+     */
+    static int index(int x, int y, int z) {
+        return y << 8 | z << 4 | x;
+    }
+
+    /**
+     * Returns the block state of the given index.
+     *
+     * @param idx block index within the section
+     * @return block state of the given index
+     */
+    int getFlatBlock(int idx);
+
+    /**
+     * Returns the block state of the section coordinate.
+     *
+     * @param x section x
+     * @param y section y
+     * @param z section z
+     * @return block state of the given section coordinate
+     */
+    default int getFlatBlock(int x, int y, int z) {
+        return getFlatBlock(index(x, y, z));
+    }
+
+    /**
+     * Set a block state in the chunk section.
+     * This method will not update non-air blocks count.
+     *
+     * @param idx block index within the section
+     * @param id  raw or flat id of the block state
+     */
+    void setFlatBlock(int idx, int id);
+
+    /**
+     * Set a block state in the chunk section.
+     * This method will not update non-air blocks count.
+     *
+     * @param x  section x
+     * @param y  section y
+     * @param z  section z
+     * @param id raw or flat id of the block state
+     */
+    default void setFlatBlock(int x, int y, int z, int id) {
+        setFlatBlock(index(x, y, z), id);
+    }
+
+    default int getBlockWithoutData(int x, int y, int z) {
+        return getFlatBlock(x, y, z) >> 4;
+    }
+
+    default int getBlockData(int x, int y, int z) {
+        return getFlatBlock(x, y, z) & 0xF;
+    }
+
+    /**
+     * Set a block in the chunks.
+     * This method will not update non-air blocks count.
+     *
+     * @param x    Block X
+     * @param y    Block Y
+     * @param z    Block Z
+     * @param type The type of the block
+     * @param data The data value of the block
+     */
+    default void setBlockWithData(int x, int y, int z, int type, int data) {
+        setFlatBlock(index(x, y, z), type << 4 | (data & 0xF));
+    }
+
+    default void setBlockWithData(int idx, int type, int data) {
+        setFlatBlock(idx, type << 4 | (data & 0xF));
+    }
+
+    /**
+     * Sets a block to the given palette index.
+     *
+     * @param idx   block index
+     * @param index palette index
+     */
+    void setPaletteIndex(int idx, int index);
+
+    /**
+     * Returns the palette index of the given block index.
+     *
+     * @param idx block index
+     * @return palette index of the given block index
+     */
+    int getPaletteIndex(int idx);
+
+    /**
+     * Returns the size of the palette.
+     *
+     * @return palette size
+     */
+    int getPaletteSize();
+
+    /**
+     * Returns the block state assigned to the given palette index.
+     *
+     * @param index palette index
+     * @return block state assigned to the given palette index
+     */
+    int getPaletteEntry(int index);
+
+    /**
+     * Assigns a block state assigned to the given palette index.
+     *
+     * @param index palette index
+     * @param id    block state
+     */
+    void setPaletteEntry(int index, int id);
+
+    /**
+     * Replaces a block state in the palette.
+     *
+     * @param oldId old block state
+     * @param newId new block state
+     */
+    void replacePaletteEntry(int oldId, int newId);
+
+    /**
+     * Adds a new block state to the palette.
+     *
+     * @param id block state
+     */
+    void addPaletteEntry(int id);
+
+    /**
+     * Clears the palette.
+     */
+    void clearPalette();
+
+    /**
+     * Returns the number of non-air blocks in this section.
+     *
+     * @return non-air blocks in this section
+     */
+    int getNonAirBlocksCount();
+
+    void setNonAirBlocksCount(int nonAirBlocksCount);
+
+    /**
+     * Returns whether this section holds light data.
+     * Only true for &lt; 1.14 chunks.
+     *
+     * @return whether this section holds light data
+     */
+    default boolean hasLight() {
+        return getLight() != null;
+    }
+
+    /**
+     * Returns the light of the chunk section.
+     * Only present for &lt; 1.14 chunks, otherwise sent separately.
+     *
+     * @return chunk section light if present
+     */
+    @Nullable ChunkSectionLight getLight();
+
+    void setLight(@Nullable ChunkSectionLight light);
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/ChunkSectionImpl.java

@@ -0,0 +1,160 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.chunks;
+
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
+import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
+import it.unimi.dsi.fastutil.ints.IntArrayList;
+import it.unimi.dsi.fastutil.ints.IntList;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public class ChunkSectionImpl implements ChunkSection {
+
+    private final IntList palette;
+    private final Int2IntMap inversePalette;
+    private final int[] blocks;
+    private ChunkSectionLight light;
+    private int nonAirBlocksCount;
+
+    public ChunkSectionImpl(boolean holdsLight) {
+        this.blocks = new int[SIZE];
+        palette = new IntArrayList();
+        inversePalette = new Int2IntOpenHashMap();
+        inversePalette.defaultReturnValue(-1);
+        if (holdsLight) {
+            this.light = new ChunkSectionLightImpl();
+        }
+    }
+
+    public ChunkSectionImpl(boolean holdsLight, int expectedPaletteLength) {
+        this.blocks = new int[SIZE];
+        if (holdsLight) {
+            this.light = new ChunkSectionLightImpl();
+        }
+
+        // Pre-size the palette array/map
+        palette = new IntArrayList(expectedPaletteLength);
+        inversePalette = new Int2IntOpenHashMap(expectedPaletteLength);
+        inversePalette.defaultReturnValue(-1);
+    }
+
+    @Override
+    public int getFlatBlock(int idx) {
+        int index = blocks[idx];
+        return palette.getInt(index);
+    }
+
+    @Override
+    public void setFlatBlock(int idx, int id) {
+        int index = inversePalette.get(id);
+        if (index == -1) {
+            index = palette.size();
+            palette.add(id);
+            inversePalette.put(id, index);
+        }
+
+        blocks[idx] = index;
+    }
+
+    @Override
+    public int getPaletteIndex(int idx) {
+        return blocks[idx];
+    }
+
+    @Override
+    public void setPaletteIndex(int idx, int index) {
+        blocks[idx] = index;
+    }
+
+    @Override
+    public int getPaletteSize() {
+        return palette.size();
+    }
+
+    @Override
+    public int getPaletteEntry(int index) {
+        return palette.getInt(index);
+    }
+
+    @Override
+    public void setPaletteEntry(int index, int id) {
+        int oldId = palette.set(index, id);
+        if (oldId == id) return;
+
+        inversePalette.put(id, index);
+        if (inversePalette.get(oldId) == index) {
+            inversePalette.remove(oldId);
+            for (int i = 0; i < palette.size(); i++) {
+                if (palette.getInt(i) == oldId) {
+                    inversePalette.put(oldId, i);
+                    break;
+                }
+            }
+        }
+    }
+
+    @Override
+    public void replacePaletteEntry(int oldId, int newId) {
+        int index = inversePalette.remove(oldId);
+        if (index == -1) return;
+
+        inversePalette.put(newId, index);
+        for (int i = 0; i < palette.size(); i++) {
+            if (palette.getInt(i) == oldId) {
+                palette.set(i, newId);
+            }
+        }
+    }
+
+    @Override
+    public void addPaletteEntry(int id) {
+        inversePalette.put(id, palette.size());
+        palette.add(id);
+    }
+
+    @Override
+    public void clearPalette() {
+        palette.clear();
+        inversePalette.clear();
+    }
+
+    @Override
+    public int getNonAirBlocksCount() {
+        return nonAirBlocksCount;
+    }
+
+    @Override
+    public void setNonAirBlocksCount(int nonAirBlocksCount) {
+        this.nonAirBlocksCount = nonAirBlocksCount;
+    }
+
+    @Override
+    public @Nullable ChunkSectionLight getLight() {
+        return light;
+    }
+
+    @Override
+    public void setLight(@Nullable ChunkSectionLight light) {
+        this.light = light;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/ChunkSectionLight.java

@@ -0,0 +1,113 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.chunks;
+
+import io.netty.buffer.ByteBuf;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public interface ChunkSectionLight {
+
+    /**
+     * Length of the sky and block light nibble arrays.
+     */
+    int LIGHT_LENGTH = 16 * 16 * 16 / 2; // Dimensions / 2 (nibble bit count)
+
+    /**
+     * Returns whether the section has sky light.
+     *
+     * @return true if skylight is present
+     */
+    boolean hasSkyLight();
+
+    /**
+     * Returns whether the section has block light.
+     * This returns true unless specifically set to null.
+     *
+     * @return true if skylight is present
+     */
+    boolean hasBlockLight();
+
+    /**
+     * Returns the nibblearray's raw sky light byte array if present.
+     *
+     * @return the nibblearray's raw sky light byte array if present
+     * @see #hasSkyLight()
+     */
+    byte @Nullable [] getSkyLight();
+
+    /**
+     * Returns the nibblearray's raw block light byte array if present.
+     *
+     * @return the nibblearray's raw block light byte array if present
+     * @see #hasBlockLight()
+     */
+    byte @Nullable [] getBlockLight();
+
+    /**
+     * Set the sky light array.
+     *
+     * @param data raw sky light data
+     */
+    void setSkyLight(byte[] data);
+
+    /**
+     * Set the block light array.
+     *
+     * @param data raw block light data
+     */
+    void setBlockLight(byte[] data);
+
+    /**
+     * Returns the sky light nibblearray.
+     *
+     * @return sky light nibblearray
+     * @see #hasSkyLight()
+     */
+    @Nullable NibbleArray getSkyLightNibbleArray();
+
+    /**
+     * Returns the block light nibblearray.
+     *
+     * @return block light nibblearray
+     * @see #hasBlockLight()
+     */
+    @Nullable NibbleArray getBlockLightNibbleArray();
+
+    void readSkyLight(ByteBuf input);
+
+    void readBlockLight(ByteBuf input);
+
+    /**
+     * Write the sky light to a buffer.
+     *
+     * @param output buffer to write to
+     */
+    void writeSkyLight(ByteBuf output);
+
+    /**
+     * Write the block light to a buffer.
+     *
+     * @param output buffer to write to
+     */
+    void writeBlockLight(ByteBuf output);
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/ChunkSectionLightImpl.java

@@ -0,0 +1,113 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.chunks;
+
+import io.netty.buffer.ByteBuf;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public class ChunkSectionLightImpl implements ChunkSectionLight {
+
+    private NibbleArray blockLight;
+    private NibbleArray skyLight;
+
+    public ChunkSectionLightImpl() {
+        // Block light is always written
+        this.blockLight = new NibbleArray(ChunkSection.SIZE);
+    }
+
+    @Override
+    public void setBlockLight(byte[] data) {
+        if (data.length != LIGHT_LENGTH) throw new IllegalArgumentException("Data length != " + LIGHT_LENGTH);
+        if (this.blockLight == null) {
+            this.blockLight = new NibbleArray(data);
+        } else {
+            this.blockLight.setHandle(data);
+        }
+    }
+
+    @Override
+    public void setSkyLight(byte[] data) {
+        if (data.length != LIGHT_LENGTH) throw new IllegalArgumentException("Data length != " + LIGHT_LENGTH);
+        if (this.skyLight == null) {
+            this.skyLight = new NibbleArray(data);
+        } else {
+            this.skyLight.setHandle(data);
+        }
+    }
+
+    @Override
+    public byte @Nullable [] getBlockLight() {
+        return blockLight == null ? null : blockLight.getHandle();
+    }
+
+    @Override
+    public @Nullable NibbleArray getBlockLightNibbleArray() {
+        return blockLight;
+    }
+
+    @Override
+    public byte @Nullable [] getSkyLight() {
+        return skyLight == null ? null : skyLight.getHandle();
+    }
+
+    @Override
+    public @Nullable NibbleArray getSkyLightNibbleArray() {
+        return skyLight;
+    }
+
+    @Override
+    public void readBlockLight(ByteBuf input) {
+        if (this.blockLight == null) {
+            this.blockLight = new NibbleArray(LIGHT_LENGTH * 2);
+        }
+        input.readBytes(this.blockLight.getHandle());
+    }
+
+    @Override
+    public void readSkyLight(ByteBuf input) {
+        if (this.skyLight == null) {
+            this.skyLight = new NibbleArray(LIGHT_LENGTH * 2);
+        }
+        input.readBytes(this.skyLight.getHandle());
+    }
+
+    @Override
+    public void writeBlockLight(ByteBuf output) {
+        output.writeBytes(blockLight.getHandle());
+    }
+
+    @Override
+    public void writeSkyLight(ByteBuf output) {
+        output.writeBytes(skyLight.getHandle());
+    }
+
+    @Override
+    public boolean hasSkyLight() {
+        return skyLight != null;
+    }
+
+    @Override
+    public boolean hasBlockLight() {
+        return blockLight != null;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/chunks/NibbleArray.java

@@ -1,4 +1,26 @@
-package us.myles.ViaVersion.api.minecraft.chunks;
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.chunks;
 
 import java.util.Arrays;
 

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/Entity1_10Types.java

@@ -1,6 +1,28 @@
-package us.myles.ViaVersion.api.entities;
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.entities;
 
-import us.myles.ViaVersion.api.Via;
+import com.viaversion.viaversion.api.Via;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -25,7 +47,7 @@ public class Entity1_10Types {
         return type.get();
     }
 
-    public enum EntityType implements us.myles.ViaVersion.api.entities.EntityType {
+    public enum EntityType implements com.viaversion.viaversion.api.minecraft.entities.EntityType {
         ENTITY(-1),
         DROPPED_ITEM(1, ENTITY),
         EXPERIENCE_ORB(2, ENTITY),
@@ -150,7 +172,7 @@ public class Entity1_10Types {
         }
     }
 
-    public enum ObjectType implements us.myles.ViaVersion.api.entities.ObjectType {
+    public enum ObjectType implements com.viaversion.viaversion.api.minecraft.entities.ObjectType {
         BOAT(1, EntityType.BOAT),
         ITEM(2, EntityType.DROPPED_ITEM),
         AREA_EFFECT_CLOUD(3, EntityType.AREA_EFFECT_CLOUD),

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/Entity1_11Types.java

@@ -1,6 +1,28 @@
-package us.myles.ViaVersion.api.entities;
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.entities;
 
-import us.myles.ViaVersion.api.Via;
+import com.viaversion.viaversion.api.Via;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -25,7 +47,7 @@ public class Entity1_11Types {
         return type.get();
     }
 
-    public enum EntityType implements us.myles.ViaVersion.api.entities.EntityType {
+    public enum EntityType implements com.viaversion.viaversion.api.minecraft.entities.EntityType {
         ENTITY(-1),
         DROPPED_ITEM(1, ENTITY),
         EXPERIENCE_ORB(2, ENTITY),
@@ -178,7 +200,7 @@ public class Entity1_11Types {
         }
     }
 
-    public enum ObjectType implements us.myles.ViaVersion.api.entities.ObjectType {
+    public enum ObjectType implements com.viaversion.viaversion.api.minecraft.entities.ObjectType {
         BOAT(1, EntityType.BOAT),
         ITEM(2, EntityType.DROPPED_ITEM),
         AREA_EFFECT_CLOUD(3, EntityType.AREA_EFFECT_CLOUD),

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/Entity1_12Types.java

@@ -1,16 +1,29 @@
 /*
- * Copyright (c) 2016 Matsv
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
  *
- * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
  *
- * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
  *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
  */
 
-package us.myles.ViaVersion.api.entities;
+package com.viaversion.viaversion.api.minecraft.entities;
 
-import us.myles.ViaVersion.api.Via;
+import com.viaversion.viaversion.api.Via;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -35,7 +48,7 @@ public class Entity1_12Types {
         return type.get();
     }
 
-    public enum EntityType implements us.myles.ViaVersion.api.entities.EntityType {
+    public enum EntityType implements com.viaversion.viaversion.api.minecraft.entities.EntityType {
         ENTITY(-1),
         DROPPED_ITEM(1, ENTITY),
         EXPERIENCE_ORB(2, ENTITY),
@@ -191,7 +204,7 @@ public class Entity1_12Types {
         }
     }
 
-    public enum ObjectType implements us.myles.ViaVersion.api.entities.ObjectType {
+    public enum ObjectType implements com.viaversion.viaversion.api.minecraft.entities.ObjectType {
         BOAT(1, EntityType.BOAT),
         ITEM(2, EntityType.DROPPED_ITEM),
         AREA_EFFECT_CLOUD(3, EntityType.AREA_EFFECT_CLOUD),

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/Entity1_13Types.java

@@ -1,12 +1,33 @@
-package us.myles.ViaVersion.api.entities;
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.entities;
 
-import us.myles.ViaVersion.api.Via;
+import com.viaversion.viaversion.api.Via;
 
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
 
-// TODO auto generate 18w11a with PAaaS
 public class Entity1_13Types {
 
     public static EntityType getTypeFromId(int typeID, boolean isObject) {
@@ -25,7 +46,7 @@ public class Entity1_13Types {
         return type.get();
     }
 
-    public enum EntityType implements us.myles.ViaVersion.api.entities.EntityType {
+    public enum EntityType implements com.viaversion.viaversion.api.minecraft.entities.EntityType {
         // Auto generated
 
         ENTITY(-1), // abm
@@ -232,7 +253,7 @@ public class Entity1_13Types {
         }
     }
 
-    public enum ObjectType implements us.myles.ViaVersion.api.entities.ObjectType {
+    public enum ObjectType implements com.viaversion.viaversion.api.minecraft.entities.ObjectType {
         BOAT(1, EntityType.BOAT),
         ITEM(2, EntityType.ITEM),
         AREA_EFFECT_CLOUD(3, EntityType.AREA_EFFECT_CLOUD),

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/Entity1_14Types.java

@@ -0,0 +1,234 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.entities;
+
+import com.viaversion.viaversion.util.EntityTypeUtil;
+
+public enum Entity1_14Types implements EntityType {
+
+    ENTITY(-1),
+
+    AREA_EFFECT_CLOUD(0, ENTITY),
+    END_CRYSTAL(17, ENTITY),
+    EVOKER_FANGS(21, ENTITY),
+    EXPERIENCE_ORB(23, ENTITY),
+    EYE_OF_ENDER(24, ENTITY),
+    FALLING_BLOCK(25, ENTITY),
+    FIREWORK_ROCKET(26, ENTITY),
+    ITEM(34, ENTITY),
+    LLAMA_SPIT(39, ENTITY),
+    TNT(58, ENTITY),
+    SHULKER_BULLET(63, ENTITY),
+    FISHING_BOBBER(101, ENTITY),
+
+    LIVINGENTITY(-1, ENTITY),
+    ARMOR_STAND(1, LIVINGENTITY),
+    PLAYER(100, LIVINGENTITY),
+
+    ABSTRACT_INSENTIENT(-1, LIVINGENTITY),
+    ENDER_DRAGON(18, ABSTRACT_INSENTIENT),
+
+    ABSTRACT_CREATURE(-1, ABSTRACT_INSENTIENT),
+
+    ABSTRACT_AGEABLE(-1, ABSTRACT_CREATURE),
+    VILLAGER(84, ABSTRACT_AGEABLE),
+    WANDERING_TRADER(88, ABSTRACT_AGEABLE),
+
+    // Animals
+    ABSTRACT_ANIMAL(-1, ABSTRACT_AGEABLE),
+    DOLPHIN(13, ABSTRACT_INSENTIENT),
+    CHICKEN(8, ABSTRACT_ANIMAL),
+    COW(10, ABSTRACT_ANIMAL),
+    MOOSHROOM(49, COW),
+    PANDA(52, ABSTRACT_INSENTIENT),
+    PIG(54, ABSTRACT_ANIMAL),
+    POLAR_BEAR(57, ABSTRACT_ANIMAL),
+    RABBIT(59, ABSTRACT_ANIMAL),
+    SHEEP(61, ABSTRACT_ANIMAL),
+    TURTLE(77, ABSTRACT_ANIMAL),
+    FOX(27, ABSTRACT_ANIMAL),
+
+    ABSTRACT_TAMEABLE_ANIMAL(-1, ABSTRACT_ANIMAL),
+    CAT(6, ABSTRACT_TAMEABLE_ANIMAL),
+    OCELOT(50, ABSTRACT_TAMEABLE_ANIMAL),
+    WOLF(93, ABSTRACT_TAMEABLE_ANIMAL),
+
+    ABSTRACT_PARROT(-1, ABSTRACT_TAMEABLE_ANIMAL),
+    PARROT(53, ABSTRACT_PARROT),
+
+    // Horses
+    ABSTRACT_HORSE(-1, ABSTRACT_ANIMAL),
+    CHESTED_HORSE(-1, ABSTRACT_HORSE),
+    DONKEY(12, CHESTED_HORSE),
+    MULE(48, CHESTED_HORSE),
+    LLAMA(38, CHESTED_HORSE),
+    TRADER_LLAMA(75, CHESTED_HORSE),
+    HORSE(31, ABSTRACT_HORSE),
+    SKELETON_HORSE(66, ABSTRACT_HORSE),
+    ZOMBIE_HORSE(95, ABSTRACT_HORSE),
+
+    // Golem
+    ABSTRACT_GOLEM(-1, ABSTRACT_CREATURE),
+    SNOW_GOLEM(69, ABSTRACT_GOLEM),
+    IRON_GOLEM(85, ABSTRACT_GOLEM),
+    SHULKER(62, ABSTRACT_GOLEM),
+
+    // Fish
+    ABSTRACT_FISHES(-1, ABSTRACT_CREATURE),
+    COD(9, ABSTRACT_FISHES),
+    PUFFERFISH(55, ABSTRACT_FISHES),
+    SALMON(60, ABSTRACT_FISHES),
+    TROPICAL_FISH(76, ABSTRACT_FISHES),
+
+    // Monsters
+    ABSTRACT_MONSTER(-1, ABSTRACT_CREATURE),
+    BLAZE(4, ABSTRACT_MONSTER),
+    CREEPER(11, ABSTRACT_MONSTER),
+    ENDERMITE(20, ABSTRACT_MONSTER),
+    ENDERMAN(19, ABSTRACT_MONSTER),
+    GIANT(29, ABSTRACT_MONSTER),
+    SILVERFISH(64, ABSTRACT_MONSTER),
+    VEX(83, ABSTRACT_MONSTER),
+    WITCH(89, ABSTRACT_MONSTER),
+    WITHER(90, ABSTRACT_MONSTER),
+    RAVAGER(98, ABSTRACT_MONSTER),
+
+    // Illagers
+    ABSTRACT_ILLAGER_BASE(-1, ABSTRACT_MONSTER),
+    ABSTRACT_EVO_ILLU_ILLAGER(-1, ABSTRACT_ILLAGER_BASE),
+    EVOKER(22, ABSTRACT_EVO_ILLU_ILLAGER),
+    ILLUSIONER(33, ABSTRACT_EVO_ILLU_ILLAGER),
+    VINDICATOR(86, ABSTRACT_ILLAGER_BASE),
+    PILLAGER(87, ABSTRACT_ILLAGER_BASE),
+
+    // Skeletons
+    ABSTRACT_SKELETON(-1, ABSTRACT_MONSTER),
+    SKELETON(65, ABSTRACT_SKELETON),
+    STRAY(74, ABSTRACT_SKELETON),
+    WITHER_SKELETON(91, ABSTRACT_SKELETON),
+
+    // Guardians
+    GUARDIAN(30, ABSTRACT_MONSTER),
+    ELDER_GUARDIAN(16, GUARDIAN),
+
+    // Spiders
+    SPIDER(72, ABSTRACT_MONSTER),
+    CAVE_SPIDER(7, SPIDER),
+
+    // Zombies - META CHECKED
+    ZOMBIE(94, ABSTRACT_MONSTER),
+    DROWNED(15, ZOMBIE),
+    HUSK(32, ZOMBIE),
+    ZOMBIE_PIGMAN(56, ZOMBIE),
+    ZOMBIE_VILLAGER(96, ZOMBIE),
+
+    // Flying entities
+    ABSTRACT_FLYING(-1, ABSTRACT_INSENTIENT),
+    GHAST(28, ABSTRACT_FLYING),
+    PHANTOM(97, ABSTRACT_FLYING),
+
+    ABSTRACT_AMBIENT(-1, ABSTRACT_INSENTIENT),
+    BAT(3, ABSTRACT_AMBIENT),
+
+    ABSTRACT_WATERMOB(-1, ABSTRACT_INSENTIENT),
+    SQUID(73, ABSTRACT_WATERMOB),
+
+    // Slimes
+    SLIME(67, ABSTRACT_INSENTIENT),
+    MAGMA_CUBE(40, SLIME),
+
+    // Hangable objects
+    ABSTRACT_HANGING(-1, ENTITY),
+    LEASH_KNOT(37, ABSTRACT_HANGING),
+    ITEM_FRAME(35, ABSTRACT_HANGING),
+    PAINTING(51, ABSTRACT_HANGING),
+
+    ABSTRACT_LIGHTNING(-1, ENTITY),
+    LIGHTNING_BOLT(99, ABSTRACT_LIGHTNING),
+
+    // Arrows
+    ABSTRACT_ARROW(-1, ENTITY),
+    ARROW(2, ABSTRACT_ARROW),
+    SPECTRAL_ARROW(71, ABSTRACT_ARROW),
+    TRIDENT(82, ABSTRACT_ARROW),
+
+    // Fireballs
+    ABSTRACT_FIREBALL(-1, ENTITY),
+    DRAGON_FIREBALL(14, ABSTRACT_FIREBALL),
+    FIREBALL(36, ABSTRACT_FIREBALL),
+    SMALL_FIREBALL(68, ABSTRACT_FIREBALL),
+    WITHER_SKULL(92, ABSTRACT_FIREBALL),
+
+    // Projectiles
+    PROJECTILE_ABSTRACT(-1, ENTITY),
+    SNOWBALL(70, PROJECTILE_ABSTRACT),
+    ENDER_PEARL(79, PROJECTILE_ABSTRACT),
+    EGG(78, PROJECTILE_ABSTRACT),
+    POTION(81, PROJECTILE_ABSTRACT),
+    EXPERIENCE_BOTTLE(80, PROJECTILE_ABSTRACT),
+
+    // Vehicles
+    MINECART_ABSTRACT(-1, ENTITY),
+    CHESTED_MINECART_ABSTRACT(-1, MINECART_ABSTRACT),
+    CHEST_MINECART(42, CHESTED_MINECART_ABSTRACT),
+    HOPPER_MINECART(45, CHESTED_MINECART_ABSTRACT),
+    MINECART(41, MINECART_ABSTRACT),
+    FURNACE_MINECART(44, MINECART_ABSTRACT),
+    COMMAND_BLOCK_MINECART(43, MINECART_ABSTRACT),
+    TNT_MINECART(47, MINECART_ABSTRACT),
+    SPAWNER_MINECART(46, MINECART_ABSTRACT),
+    BOAT(5, ENTITY);
+
+    private static final EntityType[] TYPES;
+
+    private final int id;
+    private final EntityType parent;
+
+    Entity1_14Types(int id) {
+        this.id = id;
+        this.parent = null;
+    }
+
+    Entity1_14Types(int id, EntityType parent) {
+        this.id = id;
+        this.parent = parent;
+    }
+
+    @Override
+    public int getId() {
+        return id;
+    }
+
+    @Override
+    public EntityType getParent() {
+        return parent;
+    }
+
+    static {
+        TYPES = EntityTypeUtil.toOrderedArray(values());
+    }
+
+    public static EntityType getTypeFromId(int typeId) {
+        return EntityTypeUtil.getTypeFromId(TYPES, typeId, ENTITY);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/Entity1_15Types.java

@@ -0,0 +1,236 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.entities;
+
+import com.viaversion.viaversion.util.EntityTypeUtil;
+
+public enum Entity1_15Types implements EntityType {
+
+    ENTITY(-1),
+
+    AREA_EFFECT_CLOUD(0, ENTITY),
+    END_CRYSTAL(18, ENTITY),
+    EVOKER_FANGS(22, ENTITY),
+    EXPERIENCE_ORB(24, ENTITY),
+    EYE_OF_ENDER(25, ENTITY),
+    FALLING_BLOCK(26, ENTITY),
+    FIREWORK_ROCKET(27, ENTITY),
+    ITEM(35, ENTITY),
+    LLAMA_SPIT(40, ENTITY),
+    TNT(59, ENTITY),
+    SHULKER_BULLET(64, ENTITY),
+    FISHING_BOBBER(102, ENTITY),
+
+    LIVINGENTITY(-1, ENTITY),
+    ARMOR_STAND(1, LIVINGENTITY),
+    PLAYER(101, LIVINGENTITY),
+
+    ABSTRACT_INSENTIENT(-1, LIVINGENTITY),
+    ENDER_DRAGON(19, ABSTRACT_INSENTIENT),
+
+    BEE(4, ABSTRACT_INSENTIENT),
+
+    ABSTRACT_CREATURE(-1, ABSTRACT_INSENTIENT),
+
+    ABSTRACT_AGEABLE(-1, ABSTRACT_CREATURE),
+    VILLAGER(85, ABSTRACT_AGEABLE),
+    WANDERING_TRADER(89, ABSTRACT_AGEABLE),
+
+    // Animals
+    ABSTRACT_ANIMAL(-1, ABSTRACT_AGEABLE),
+    DOLPHIN(14, ABSTRACT_INSENTIENT),
+    CHICKEN(9, ABSTRACT_ANIMAL),
+    COW(11, ABSTRACT_ANIMAL),
+    MOOSHROOM(50, COW),
+    PANDA(53, ABSTRACT_INSENTIENT),
+    PIG(55, ABSTRACT_ANIMAL),
+    POLAR_BEAR(58, ABSTRACT_ANIMAL),
+    RABBIT(60, ABSTRACT_ANIMAL),
+    SHEEP(62, ABSTRACT_ANIMAL),
+    TURTLE(78, ABSTRACT_ANIMAL),
+    FOX(28, ABSTRACT_ANIMAL),
+
+    ABSTRACT_TAMEABLE_ANIMAL(-1, ABSTRACT_ANIMAL),
+    CAT(7, ABSTRACT_TAMEABLE_ANIMAL),
+    OCELOT(51, ABSTRACT_TAMEABLE_ANIMAL),
+    WOLF(94, ABSTRACT_TAMEABLE_ANIMAL),
+
+    ABSTRACT_PARROT(-1, ABSTRACT_TAMEABLE_ANIMAL),
+    PARROT(54, ABSTRACT_PARROT),
+
+    // Horses
+    ABSTRACT_HORSE(-1, ABSTRACT_ANIMAL),
+    CHESTED_HORSE(-1, ABSTRACT_HORSE),
+    DONKEY(13, CHESTED_HORSE),
+    MULE(49, CHESTED_HORSE),
+    LLAMA(39, CHESTED_HORSE),
+    TRADER_LLAMA(76, CHESTED_HORSE),
+    HORSE(32, ABSTRACT_HORSE),
+    SKELETON_HORSE(67, ABSTRACT_HORSE),
+    ZOMBIE_HORSE(96, ABSTRACT_HORSE),
+
+    // Golem
+    ABSTRACT_GOLEM(-1, ABSTRACT_CREATURE),
+    SNOW_GOLEM(70, ABSTRACT_GOLEM),
+    IRON_GOLEM(86, ABSTRACT_GOLEM),
+    SHULKER(63, ABSTRACT_GOLEM),
+
+    // Fish
+    ABSTRACT_FISHES(-1, ABSTRACT_CREATURE),
+    COD(10, ABSTRACT_FISHES),
+    PUFFERFISH(56, ABSTRACT_FISHES),
+    SALMON(61, ABSTRACT_FISHES),
+    TROPICAL_FISH(77, ABSTRACT_FISHES),
+
+    // Monsters
+    ABSTRACT_MONSTER(-1, ABSTRACT_CREATURE),
+    BLAZE(5, ABSTRACT_MONSTER),
+    CREEPER(12, ABSTRACT_MONSTER),
+    ENDERMITE(21, ABSTRACT_MONSTER),
+    ENDERMAN(20, ABSTRACT_MONSTER),
+    GIANT(30, ABSTRACT_MONSTER),
+    SILVERFISH(65, ABSTRACT_MONSTER),
+    VEX(84, ABSTRACT_MONSTER),
+    WITCH(90, ABSTRACT_MONSTER),
+    WITHER(91, ABSTRACT_MONSTER),
+    RAVAGER(99, ABSTRACT_MONSTER),
+
+    // Illagers
+    ABSTRACT_ILLAGER_BASE(-1, ABSTRACT_MONSTER),
+    ABSTRACT_EVO_ILLU_ILLAGER(-1, ABSTRACT_ILLAGER_BASE),
+    EVOKER(23, ABSTRACT_EVO_ILLU_ILLAGER),
+    ILLUSIONER(34, ABSTRACT_EVO_ILLU_ILLAGER),
+    VINDICATOR(87, ABSTRACT_ILLAGER_BASE),
+    PILLAGER(88, ABSTRACT_ILLAGER_BASE),
+
+    // Skeletons
+    ABSTRACT_SKELETON(-1, ABSTRACT_MONSTER),
+    SKELETON(66, ABSTRACT_SKELETON),
+    STRAY(75, ABSTRACT_SKELETON),
+    WITHER_SKELETON(92, ABSTRACT_SKELETON),
+
+    // Guardians
+    GUARDIAN(31, ABSTRACT_MONSTER),
+    ELDER_GUARDIAN(17, GUARDIAN),
+
+    // Spiders
+    SPIDER(73, ABSTRACT_MONSTER),
+    CAVE_SPIDER(8, SPIDER),
+
+    // Zombies
+    ZOMBIE(95, ABSTRACT_MONSTER),
+    DROWNED(16, ZOMBIE),
+    HUSK(33, ZOMBIE),
+    ZOMBIE_PIGMAN(57, ZOMBIE),
+    ZOMBIE_VILLAGER(97, ZOMBIE),
+
+    // Flying entities
+    ABSTRACT_FLYING(-1, ABSTRACT_INSENTIENT),
+    GHAST(29, ABSTRACT_FLYING),
+    PHANTOM(98, ABSTRACT_FLYING),
+
+    ABSTRACT_AMBIENT(-1, ABSTRACT_INSENTIENT),
+    BAT(3, ABSTRACT_AMBIENT),
+
+    ABSTRACT_WATERMOB(-1, ABSTRACT_INSENTIENT),
+    SQUID(74, ABSTRACT_WATERMOB),
+
+    // Slimes
+    SLIME(68, ABSTRACT_INSENTIENT),
+    MAGMA_CUBE(41, SLIME),
+
+    // Hangable objects
+    ABSTRACT_HANGING(-1, ENTITY),
+    LEASH_KNOT(38, ABSTRACT_HANGING),
+    ITEM_FRAME(36, ABSTRACT_HANGING),
+    PAINTING(52, ABSTRACT_HANGING),
+
+    ABSTRACT_LIGHTNING(-1, ENTITY),
+    LIGHTNING_BOLT(100, ABSTRACT_LIGHTNING),
+
+    // Arrows
+    ABSTRACT_ARROW(-1, ENTITY),
+    ARROW(2, ABSTRACT_ARROW),
+    SPECTRAL_ARROW(72, ABSTRACT_ARROW),
+    TRIDENT(83, ABSTRACT_ARROW),
+
+    // Fireballs
+    ABSTRACT_FIREBALL(-1, ENTITY),
+    DRAGON_FIREBALL(15, ABSTRACT_FIREBALL),
+    FIREBALL(37, ABSTRACT_FIREBALL),
+    SMALL_FIREBALL(69, ABSTRACT_FIREBALL),
+    WITHER_SKULL(93, ABSTRACT_FIREBALL),
+
+    // Projectiles
+    PROJECTILE_ABSTRACT(-1, ENTITY),
+    SNOWBALL(71, PROJECTILE_ABSTRACT),
+    ENDER_PEARL(80, PROJECTILE_ABSTRACT),
+    EGG(79, PROJECTILE_ABSTRACT),
+    POTION(82, PROJECTILE_ABSTRACT),
+    EXPERIENCE_BOTTLE(81, PROJECTILE_ABSTRACT),
+
+    // Vehicles
+    MINECART_ABSTRACT(-1, ENTITY),
+    CHESTED_MINECART_ABSTRACT(-1, MINECART_ABSTRACT),
+    CHEST_MINECART(43, CHESTED_MINECART_ABSTRACT),
+    HOPPER_MINECART(46, CHESTED_MINECART_ABSTRACT),
+    MINECART(42, MINECART_ABSTRACT),
+    FURNACE_MINECART(45, MINECART_ABSTRACT),
+    COMMAND_BLOCK_MINECART(44, MINECART_ABSTRACT),
+    TNT_MINECART(48, MINECART_ABSTRACT),
+    SPAWNER_MINECART(47, MINECART_ABSTRACT),
+    BOAT(6, ENTITY);
+
+    private static final EntityType[] TYPES;
+
+    private final int id;
+    private final EntityType parent;
+
+    Entity1_15Types(int id) {
+        this.id = id;
+        this.parent = null;
+    }
+
+    Entity1_15Types(int id, EntityType parent) {
+        this.id = id;
+        this.parent = parent;
+    }
+
+    @Override
+    public int getId() {
+        return id;
+    }
+
+    @Override
+    public EntityType getParent() {
+        return parent;
+    }
+
+    static {
+        TYPES = EntityTypeUtil.toOrderedArray(values());
+    }
+
+    public static EntityType getTypeFromId(int typeId) {
+        return EntityTypeUtil.getTypeFromId(TYPES, typeId, ENTITY);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/Entity1_16Types.java

@@ -0,0 +1,241 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.entities;
+
+import com.viaversion.viaversion.util.EntityTypeUtil;
+
+public enum Entity1_16Types implements EntityType {
+
+    ENTITY(-1),
+
+    AREA_EFFECT_CLOUD(0, ENTITY),
+    END_CRYSTAL(18, ENTITY),
+    EVOKER_FANGS(23, ENTITY),
+    EXPERIENCE_ORB(24, ENTITY),
+    EYE_OF_ENDER(25, ENTITY),
+    FALLING_BLOCK(26, ENTITY),
+    FIREWORK_ROCKET(27, ENTITY),
+    ITEM(37, ENTITY),
+    LLAMA_SPIT(43, ENTITY),
+    TNT(63, ENTITY),
+    SHULKER_BULLET(70, ENTITY),
+    FISHING_BOBBER(106, ENTITY),
+
+    LIVINGENTITY(-1, ENTITY),
+    ARMOR_STAND(1, LIVINGENTITY),
+    PLAYER(105, LIVINGENTITY),
+
+    ABSTRACT_INSENTIENT(-1, LIVINGENTITY),
+    ENDER_DRAGON(19, ABSTRACT_INSENTIENT),
+
+    BEE(4, ABSTRACT_INSENTIENT),
+
+    ABSTRACT_CREATURE(-1, ABSTRACT_INSENTIENT),
+
+    ABSTRACT_AGEABLE(-1, ABSTRACT_CREATURE),
+    VILLAGER(92, ABSTRACT_AGEABLE),
+    WANDERING_TRADER(94, ABSTRACT_AGEABLE),
+
+    // Animals
+    ABSTRACT_ANIMAL(-1, ABSTRACT_AGEABLE),
+    DOLPHIN(13, ABSTRACT_INSENTIENT),
+    CHICKEN(9, ABSTRACT_ANIMAL),
+    COW(11, ABSTRACT_ANIMAL),
+    MOOSHROOM(53, COW),
+    PANDA(56, ABSTRACT_INSENTIENT),
+    PIG(59, ABSTRACT_ANIMAL),
+    POLAR_BEAR(62, ABSTRACT_ANIMAL),
+    RABBIT(65, ABSTRACT_ANIMAL),
+    SHEEP(68, ABSTRACT_ANIMAL),
+    TURTLE(90, ABSTRACT_ANIMAL),
+    FOX(28, ABSTRACT_ANIMAL),
+
+    ABSTRACT_TAMEABLE_ANIMAL(-1, ABSTRACT_ANIMAL),
+    CAT(7, ABSTRACT_TAMEABLE_ANIMAL),
+    OCELOT(54, ABSTRACT_TAMEABLE_ANIMAL),
+    WOLF(99, ABSTRACT_TAMEABLE_ANIMAL),
+
+    ABSTRACT_PARROT(-1, ABSTRACT_TAMEABLE_ANIMAL),
+    PARROT(57, ABSTRACT_PARROT),
+
+    // Horses
+    ABSTRACT_HORSE(-1, ABSTRACT_ANIMAL),
+    CHESTED_HORSE(-1, ABSTRACT_HORSE),
+    DONKEY(14, CHESTED_HORSE),
+    MULE(52, CHESTED_HORSE),
+    LLAMA(42, CHESTED_HORSE),
+    TRADER_LLAMA(88, CHESTED_HORSE),
+    HORSE(33, ABSTRACT_HORSE),
+    SKELETON_HORSE(73, ABSTRACT_HORSE),
+    ZOMBIE_HORSE(102, ABSTRACT_HORSE),
+
+    // Golem
+    ABSTRACT_GOLEM(-1, ABSTRACT_CREATURE),
+    SNOW_GOLEM(76, ABSTRACT_GOLEM),
+    IRON_GOLEM(36, ABSTRACT_GOLEM),
+    SHULKER(69, ABSTRACT_GOLEM),
+
+    // Fish
+    ABSTRACT_FISHES(-1, ABSTRACT_CREATURE),
+    COD(10, ABSTRACT_FISHES),
+    PUFFERFISH(64, ABSTRACT_FISHES),
+    SALMON(67, ABSTRACT_FISHES),
+    TROPICAL_FISH(89, ABSTRACT_FISHES),
+
+    // Monsters
+    ABSTRACT_MONSTER(-1, ABSTRACT_CREATURE),
+    BLAZE(5, ABSTRACT_MONSTER),
+    CREEPER(12, ABSTRACT_MONSTER),
+    ENDERMITE(21, ABSTRACT_MONSTER),
+    ENDERMAN(20, ABSTRACT_MONSTER),
+    GIANT(30, ABSTRACT_MONSTER),
+    SILVERFISH(71, ABSTRACT_MONSTER),
+    VEX(91, ABSTRACT_MONSTER),
+    WITCH(95, ABSTRACT_MONSTER),
+    WITHER(96, ABSTRACT_MONSTER),
+    RAVAGER(66, ABSTRACT_MONSTER),
+    PIGLIN(60, ABSTRACT_MONSTER),
+
+    HOGLIN(32, ABSTRACT_ANIMAL),
+    STRIDER(82, ABSTRACT_ANIMAL),
+    ZOGLIN(100, ABSTRACT_MONSTER),
+
+    // Illagers
+    ABSTRACT_ILLAGER_BASE(-1, ABSTRACT_MONSTER),
+    ABSTRACT_EVO_ILLU_ILLAGER(-1, ABSTRACT_ILLAGER_BASE),
+    EVOKER(22, ABSTRACT_EVO_ILLU_ILLAGER),
+    ILLUSIONER(35, ABSTRACT_EVO_ILLU_ILLAGER),
+    VINDICATOR(93, ABSTRACT_ILLAGER_BASE),
+    PILLAGER(61, ABSTRACT_ILLAGER_BASE),
+
+    // Skeletons
+    ABSTRACT_SKELETON(-1, ABSTRACT_MONSTER),
+    SKELETON(72, ABSTRACT_SKELETON),
+    STRAY(81, ABSTRACT_SKELETON),
+    WITHER_SKELETON(97, ABSTRACT_SKELETON),
+
+    // Guardians
+    GUARDIAN(31, ABSTRACT_MONSTER),
+    ELDER_GUARDIAN(17, GUARDIAN),
+
+    // Spiders
+    SPIDER(79, ABSTRACT_MONSTER),
+    CAVE_SPIDER(8, SPIDER),
+
+    // Zombies
+    ZOMBIE(101, ABSTRACT_MONSTER),
+    DROWNED(16, ZOMBIE),
+    HUSK(34, ZOMBIE),
+    ZOMBIFIED_PIGLIN(104, ZOMBIE),
+    ZOMBIE_VILLAGER(103, ZOMBIE),
+
+    // Flying entities
+    ABSTRACT_FLYING(-1, ABSTRACT_INSENTIENT),
+    GHAST(29, ABSTRACT_FLYING),
+    PHANTOM(58, ABSTRACT_FLYING),
+
+    ABSTRACT_AMBIENT(-1, ABSTRACT_INSENTIENT),
+    BAT(3, ABSTRACT_AMBIENT),
+
+    ABSTRACT_WATERMOB(-1, ABSTRACT_INSENTIENT),
+    SQUID(80, ABSTRACT_WATERMOB),
+
+    // Slimes
+    SLIME(74, ABSTRACT_INSENTIENT),
+    MAGMA_CUBE(44, SLIME),
+
+    // Hangable objects
+    ABSTRACT_HANGING(-1, ENTITY),
+    LEASH_KNOT(40, ABSTRACT_HANGING),
+    ITEM_FRAME(38, ABSTRACT_HANGING),
+    PAINTING(55, ABSTRACT_HANGING),
+
+    ABSTRACT_LIGHTNING(-1, ENTITY),
+    LIGHTNING_BOLT(41, ABSTRACT_LIGHTNING),
+
+    // Arrows
+    ABSTRACT_ARROW(-1, ENTITY),
+    ARROW(2, ABSTRACT_ARROW),
+    SPECTRAL_ARROW(78, ABSTRACT_ARROW),
+    TRIDENT(87, ABSTRACT_ARROW),
+
+    // Fireballs
+    ABSTRACT_FIREBALL(-1, ENTITY),
+    DRAGON_FIREBALL(15, ABSTRACT_FIREBALL),
+    FIREBALL(39, ABSTRACT_FIREBALL),
+    SMALL_FIREBALL(75, ABSTRACT_FIREBALL),
+    WITHER_SKULL(98, ABSTRACT_FIREBALL),
+
+    // Projectiles
+    PROJECTILE_ABSTRACT(-1, ENTITY),
+    SNOWBALL(77, PROJECTILE_ABSTRACT),
+    ENDER_PEARL(84, PROJECTILE_ABSTRACT),
+    EGG(83, PROJECTILE_ABSTRACT),
+    POTION(86, PROJECTILE_ABSTRACT),
+    EXPERIENCE_BOTTLE(85, PROJECTILE_ABSTRACT),
+
+    // Vehicles
+    MINECART_ABSTRACT(-1, ENTITY),
+    CHESTED_MINECART_ABSTRACT(-1, MINECART_ABSTRACT),
+    CHEST_MINECART(46, CHESTED_MINECART_ABSTRACT),
+    HOPPER_MINECART(49, CHESTED_MINECART_ABSTRACT),
+    MINECART(45, MINECART_ABSTRACT),
+    FURNACE_MINECART(48, MINECART_ABSTRACT),
+    COMMAND_BLOCK_MINECART(47, MINECART_ABSTRACT),
+    TNT_MINECART(51, MINECART_ABSTRACT),
+    SPAWNER_MINECART(50, MINECART_ABSTRACT),
+    BOAT(6, ENTITY);
+
+    private static final EntityType[] TYPES;
+
+    private final int id;
+    private final EntityType parent;
+
+    Entity1_16Types(int id) {
+        this.id = id;
+        this.parent = null;
+    }
+
+    Entity1_16Types(int id, EntityType parent) {
+        this.id = id;
+        this.parent = parent;
+    }
+
+    @Override
+    public int getId() {
+        return id;
+    }
+
+    @Override
+    public EntityType getParent() {
+        return parent;
+    }
+
+    static {
+        TYPES = EntityTypeUtil.toOrderedArray(values());
+    }
+
+    public static EntityType getTypeFromId(int typeId) {
+        return EntityTypeUtil.getTypeFromId(TYPES, typeId, ENTITY);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/Entity1_16_2Types.java

@@ -0,0 +1,245 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.entities;
+
+import com.viaversion.viaversion.util.EntityTypeUtil;
+
+public enum Entity1_16_2Types implements EntityType {
+
+    ENTITY(-1),
+
+    AREA_EFFECT_CLOUD(0, ENTITY),
+    END_CRYSTAL(18, ENTITY),
+    EVOKER_FANGS(23, ENTITY),
+    EXPERIENCE_ORB(24, ENTITY),
+    EYE_OF_ENDER(25, ENTITY),
+    FALLING_BLOCK(26, ENTITY),
+    FIREWORK_ROCKET(27, ENTITY),
+    ITEM(37, ENTITY),
+    LLAMA_SPIT(43, ENTITY),
+    TNT(64, ENTITY),
+    SHULKER_BULLET(71, ENTITY),
+    FISHING_BOBBER(107, ENTITY),
+
+    LIVINGENTITY(-1, ENTITY),
+    ARMOR_STAND(1, LIVINGENTITY),
+    PLAYER(106, LIVINGENTITY),
+
+    ABSTRACT_INSENTIENT(-1, LIVINGENTITY),
+    ENDER_DRAGON(19, ABSTRACT_INSENTIENT),
+
+    BEE(4, ABSTRACT_INSENTIENT),
+
+    ABSTRACT_CREATURE(-1, ABSTRACT_INSENTIENT),
+
+    ABSTRACT_AGEABLE(-1, ABSTRACT_CREATURE),
+    VILLAGER(93, ABSTRACT_AGEABLE),
+    WANDERING_TRADER(95, ABSTRACT_AGEABLE),
+
+    // Animals
+    ABSTRACT_ANIMAL(-1, ABSTRACT_AGEABLE),
+    DOLPHIN(13, ABSTRACT_INSENTIENT),
+    CHICKEN(9, ABSTRACT_ANIMAL),
+    COW(11, ABSTRACT_ANIMAL),
+    MOOSHROOM(53, COW),
+    PANDA(56, ABSTRACT_INSENTIENT),
+    PIG(59, ABSTRACT_ANIMAL),
+    POLAR_BEAR(63, ABSTRACT_ANIMAL),
+    RABBIT(66, ABSTRACT_ANIMAL),
+    SHEEP(69, ABSTRACT_ANIMAL),
+    TURTLE(91, ABSTRACT_ANIMAL),
+    FOX(28, ABSTRACT_ANIMAL),
+
+    ABSTRACT_TAMEABLE_ANIMAL(-1, ABSTRACT_ANIMAL),
+    CAT(7, ABSTRACT_TAMEABLE_ANIMAL),
+    OCELOT(54, ABSTRACT_TAMEABLE_ANIMAL),
+    WOLF(100, ABSTRACT_TAMEABLE_ANIMAL),
+
+    ABSTRACT_PARROT(-1, ABSTRACT_TAMEABLE_ANIMAL),
+    PARROT(57, ABSTRACT_PARROT),
+
+    // Horses
+    ABSTRACT_HORSE(-1, ABSTRACT_ANIMAL),
+    CHESTED_HORSE(-1, ABSTRACT_HORSE),
+    DONKEY(14, CHESTED_HORSE),
+    MULE(52, CHESTED_HORSE),
+    LLAMA(42, CHESTED_HORSE),
+    TRADER_LLAMA(89, CHESTED_HORSE),
+    HORSE(33, ABSTRACT_HORSE),
+    SKELETON_HORSE(74, ABSTRACT_HORSE),
+    ZOMBIE_HORSE(103, ABSTRACT_HORSE),
+
+    // Golem
+    ABSTRACT_GOLEM(-1, ABSTRACT_CREATURE),
+    SNOW_GOLEM(77, ABSTRACT_GOLEM),
+    IRON_GOLEM(36, ABSTRACT_GOLEM),
+    SHULKER(70, ABSTRACT_GOLEM),
+
+    // Fish
+    ABSTRACT_FISHES(-1, ABSTRACT_CREATURE),
+    COD(10, ABSTRACT_FISHES),
+    PUFFERFISH(65, ABSTRACT_FISHES),
+    SALMON(68, ABSTRACT_FISHES),
+    TROPICAL_FISH(90, ABSTRACT_FISHES),
+
+    // Monsters
+    ABSTRACT_MONSTER(-1, ABSTRACT_CREATURE),
+    BLAZE(5, ABSTRACT_MONSTER),
+    CREEPER(12, ABSTRACT_MONSTER),
+    ENDERMITE(21, ABSTRACT_MONSTER),
+    ENDERMAN(20, ABSTRACT_MONSTER),
+    GIANT(30, ABSTRACT_MONSTER),
+    SILVERFISH(72, ABSTRACT_MONSTER),
+    VEX(92, ABSTRACT_MONSTER),
+    WITCH(96, ABSTRACT_MONSTER),
+    WITHER(97, ABSTRACT_MONSTER),
+    RAVAGER(67, ABSTRACT_MONSTER),
+
+    ABSTRACT_PIGLIN(-1, ABSTRACT_MONSTER),
+
+    PIGLIN(60, ABSTRACT_PIGLIN),
+    PIGLIN_BRUTE(61, ABSTRACT_PIGLIN),
+
+    HOGLIN(32, ABSTRACT_ANIMAL),
+    STRIDER(83, ABSTRACT_ANIMAL),
+    ZOGLIN(101, ABSTRACT_MONSTER),
+
+    // Illagers
+    ABSTRACT_ILLAGER_BASE(-1, ABSTRACT_MONSTER),
+    ABSTRACT_EVO_ILLU_ILLAGER(-1, ABSTRACT_ILLAGER_BASE),
+    EVOKER(22, ABSTRACT_EVO_ILLU_ILLAGER),
+    ILLUSIONER(35, ABSTRACT_EVO_ILLU_ILLAGER),
+    VINDICATOR(94, ABSTRACT_ILLAGER_BASE),
+    PILLAGER(62, ABSTRACT_ILLAGER_BASE),
+
+    // Skeletons
+    ABSTRACT_SKELETON(-1, ABSTRACT_MONSTER),
+    SKELETON(73, ABSTRACT_SKELETON),
+    STRAY(82, ABSTRACT_SKELETON),
+    WITHER_SKELETON(98, ABSTRACT_SKELETON),
+
+    // Guardians
+    GUARDIAN(31, ABSTRACT_MONSTER),
+    ELDER_GUARDIAN(17, GUARDIAN),
+
+    // Spiders
+    SPIDER(80, ABSTRACT_MONSTER),
+    CAVE_SPIDER(8, SPIDER),
+
+    // Zombies
+    ZOMBIE(102, ABSTRACT_MONSTER),
+    DROWNED(16, ZOMBIE),
+    HUSK(34, ZOMBIE),
+    ZOMBIFIED_PIGLIN(105, ZOMBIE),
+    ZOMBIE_VILLAGER(104, ZOMBIE),
+
+    // Flying entities
+    ABSTRACT_FLYING(-1, ABSTRACT_INSENTIENT),
+    GHAST(29, ABSTRACT_FLYING),
+    PHANTOM(58, ABSTRACT_FLYING),
+
+    ABSTRACT_AMBIENT(-1, ABSTRACT_INSENTIENT),
+    BAT(3, ABSTRACT_AMBIENT),
+
+    ABSTRACT_WATERMOB(-1, ABSTRACT_INSENTIENT),
+    SQUID(81, ABSTRACT_WATERMOB),
+
+    // Slimes
+    SLIME(75, ABSTRACT_INSENTIENT),
+    MAGMA_CUBE(44, SLIME),
+
+    // Hangable objects
+    ABSTRACT_HANGING(-1, ENTITY),
+    LEASH_KNOT(40, ABSTRACT_HANGING),
+    ITEM_FRAME(38, ABSTRACT_HANGING),
+    PAINTING(55, ABSTRACT_HANGING),
+
+    ABSTRACT_LIGHTNING(-1, ENTITY),
+    LIGHTNING_BOLT(41, ABSTRACT_LIGHTNING),
+
+    // Arrows
+    ABSTRACT_ARROW(-1, ENTITY),
+    ARROW(2, ABSTRACT_ARROW),
+    SPECTRAL_ARROW(79, ABSTRACT_ARROW),
+    TRIDENT(88, ABSTRACT_ARROW),
+
+    // Fireballs
+    ABSTRACT_FIREBALL(-1, ENTITY),
+    DRAGON_FIREBALL(15, ABSTRACT_FIREBALL),
+    FIREBALL(39, ABSTRACT_FIREBALL),
+    SMALL_FIREBALL(76, ABSTRACT_FIREBALL),
+    WITHER_SKULL(99, ABSTRACT_FIREBALL),
+
+    // Projectiles
+    PROJECTILE_ABSTRACT(-1, ENTITY),
+    SNOWBALL(78, PROJECTILE_ABSTRACT),
+    ENDER_PEARL(85, PROJECTILE_ABSTRACT),
+    EGG(84, PROJECTILE_ABSTRACT),
+    POTION(87, PROJECTILE_ABSTRACT),
+    EXPERIENCE_BOTTLE(86, PROJECTILE_ABSTRACT),
+
+    // Vehicles
+    MINECART_ABSTRACT(-1, ENTITY),
+    CHESTED_MINECART_ABSTRACT(-1, MINECART_ABSTRACT),
+    CHEST_MINECART(46, CHESTED_MINECART_ABSTRACT),
+    HOPPER_MINECART(49, CHESTED_MINECART_ABSTRACT),
+    MINECART(45, MINECART_ABSTRACT),
+    FURNACE_MINECART(48, MINECART_ABSTRACT),
+    COMMAND_BLOCK_MINECART(47, MINECART_ABSTRACT),
+    TNT_MINECART(51, MINECART_ABSTRACT),
+    SPAWNER_MINECART(50, MINECART_ABSTRACT),
+    BOAT(6, ENTITY);
+
+    private static final EntityType[] TYPES;
+
+    private final int id;
+    private final EntityType parent;
+
+    Entity1_16_2Types(int id) {
+        this.id = id;
+        this.parent = null;
+    }
+
+    Entity1_16_2Types(int id, EntityType parent) {
+        this.id = id;
+        this.parent = parent;
+    }
+
+    @Override
+    public int getId() {
+        return id;
+    }
+
+    @Override
+    public EntityType getParent() {
+        return parent;
+    }
+
+    static {
+        TYPES = EntityTypeUtil.toOrderedArray(values());
+    }
+
+    public static EntityType getTypeFromId(int typeId) {
+        return EntityTypeUtil.getTypeFromId(TYPES, typeId, ENTITY);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/Entity1_17Types.java

@@ -0,0 +1,250 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.entities;
+
+import com.viaversion.viaversion.util.EntityTypeUtil;
+
+public enum Entity1_17Types implements EntityType {
+
+    ENTITY(-1),
+
+    AREA_EFFECT_CLOUD(0, ENTITY),
+    END_CRYSTAL(19, ENTITY),
+    EVOKER_FANGS(24, ENTITY),
+    EXPERIENCE_ORB(25, ENTITY),
+    EYE_OF_ENDER(26, ENTITY),
+    FALLING_BLOCK(27, ENTITY),
+    FIREWORK_ROCKET(28, ENTITY),
+    ITEM(41, ENTITY),
+    LLAMA_SPIT(47, ENTITY),
+    TNT(69, ENTITY),
+    SHULKER_BULLET(76, ENTITY),
+    FISHING_BOBBER(112, ENTITY),
+
+    LIVINGENTITY(-1, ENTITY),
+    ARMOR_STAND(1, LIVINGENTITY),
+    MARKER(49, ENTITY),
+    PLAYER(111, LIVINGENTITY),
+
+    ABSTRACT_INSENTIENT(-1, LIVINGENTITY),
+    ENDER_DRAGON(20, ABSTRACT_INSENTIENT),
+
+    BEE(5, ABSTRACT_INSENTIENT),
+
+    ABSTRACT_CREATURE(-1, ABSTRACT_INSENTIENT),
+
+    ABSTRACT_AGEABLE(-1, ABSTRACT_CREATURE),
+    VILLAGER(98, ABSTRACT_AGEABLE),
+    WANDERING_TRADER(100, ABSTRACT_AGEABLE),
+
+    // Animals
+    ABSTRACT_ANIMAL(-1, ABSTRACT_AGEABLE),
+    AXOLOTL(3, ABSTRACT_ANIMAL),
+    DOLPHIN(14, ABSTRACT_INSENTIENT),
+    CHICKEN(10, ABSTRACT_ANIMAL),
+    COW(12, ABSTRACT_ANIMAL),
+    MOOSHROOM(58, COW),
+    PANDA(61, ABSTRACT_INSENTIENT),
+    PIG(64, ABSTRACT_ANIMAL),
+    POLAR_BEAR(68, ABSTRACT_ANIMAL),
+    RABBIT(71, ABSTRACT_ANIMAL),
+    SHEEP(74, ABSTRACT_ANIMAL),
+    TURTLE(96, ABSTRACT_ANIMAL),
+    FOX(29, ABSTRACT_ANIMAL),
+    GOAT(34, ABSTRACT_ANIMAL),
+
+    ABSTRACT_TAMEABLE_ANIMAL(-1, ABSTRACT_ANIMAL),
+    CAT(8, ABSTRACT_TAMEABLE_ANIMAL),
+    OCELOT(59, ABSTRACT_TAMEABLE_ANIMAL),
+    WOLF(105, ABSTRACT_TAMEABLE_ANIMAL),
+
+    ABSTRACT_PARROT(-1, ABSTRACT_TAMEABLE_ANIMAL),
+    PARROT(62, ABSTRACT_PARROT),
+
+    // Horses
+    ABSTRACT_HORSE(-1, ABSTRACT_ANIMAL),
+    CHESTED_HORSE(-1, ABSTRACT_HORSE),
+    DONKEY(15, CHESTED_HORSE),
+    MULE(57, CHESTED_HORSE),
+    LLAMA(46, CHESTED_HORSE),
+    TRADER_LLAMA(94, CHESTED_HORSE),
+    HORSE(37, ABSTRACT_HORSE),
+    SKELETON_HORSE(79, ABSTRACT_HORSE),
+    ZOMBIE_HORSE(108, ABSTRACT_HORSE),
+
+    // Golem
+    ABSTRACT_GOLEM(-1, ABSTRACT_CREATURE),
+    SNOW_GOLEM(82, ABSTRACT_GOLEM),
+    IRON_GOLEM(40, ABSTRACT_GOLEM),
+    SHULKER(75, ABSTRACT_GOLEM),
+
+    // Fish
+    ABSTRACT_FISHES(-1, ABSTRACT_CREATURE),
+    COD(11, ABSTRACT_FISHES),
+    PUFFERFISH(70, ABSTRACT_FISHES),
+    SALMON(73, ABSTRACT_FISHES),
+    TROPICAL_FISH(95, ABSTRACT_FISHES),
+
+    // Monsters
+    ABSTRACT_MONSTER(-1, ABSTRACT_CREATURE),
+    BLAZE(6, ABSTRACT_MONSTER),
+    CREEPER(13, ABSTRACT_MONSTER),
+    ENDERMITE(22, ABSTRACT_MONSTER),
+    ENDERMAN(21, ABSTRACT_MONSTER),
+    GIANT(31, ABSTRACT_MONSTER),
+    SILVERFISH(77, ABSTRACT_MONSTER),
+    VEX(97, ABSTRACT_MONSTER),
+    WITCH(101, ABSTRACT_MONSTER),
+    WITHER(102, ABSTRACT_MONSTER),
+    RAVAGER(72, ABSTRACT_MONSTER),
+
+    ABSTRACT_PIGLIN(-1, ABSTRACT_MONSTER),
+
+    PIGLIN(65, ABSTRACT_PIGLIN),
+    PIGLIN_BRUTE(66, ABSTRACT_PIGLIN),
+
+    HOGLIN(36, ABSTRACT_ANIMAL),
+    STRIDER(88, ABSTRACT_ANIMAL),
+    ZOGLIN(106, ABSTRACT_MONSTER),
+
+    // Illagers
+    ABSTRACT_ILLAGER_BASE(-1, ABSTRACT_MONSTER),
+    ABSTRACT_EVO_ILLU_ILLAGER(-1, ABSTRACT_ILLAGER_BASE),
+    EVOKER(23, ABSTRACT_EVO_ILLU_ILLAGER),
+    ILLUSIONER(39, ABSTRACT_EVO_ILLU_ILLAGER),
+    VINDICATOR(99, ABSTRACT_ILLAGER_BASE),
+    PILLAGER(67, ABSTRACT_ILLAGER_BASE),
+
+    // Skeletons
+    ABSTRACT_SKELETON(-1, ABSTRACT_MONSTER),
+    SKELETON(78, ABSTRACT_SKELETON),
+    STRAY(87, ABSTRACT_SKELETON),
+    WITHER_SKELETON(103, ABSTRACT_SKELETON),
+
+    // Guardians
+    GUARDIAN(35, ABSTRACT_MONSTER),
+    ELDER_GUARDIAN(18, GUARDIAN),
+
+    // Spiders
+    SPIDER(85, ABSTRACT_MONSTER),
+    CAVE_SPIDER(9, SPIDER),
+
+    // Zombies
+    ZOMBIE(107, ABSTRACT_MONSTER),
+    DROWNED(17, ZOMBIE),
+    HUSK(38, ZOMBIE),
+    ZOMBIFIED_PIGLIN(110, ZOMBIE),
+    ZOMBIE_VILLAGER(109, ZOMBIE),
+
+    // Flying entities
+    ABSTRACT_FLYING(-1, ABSTRACT_INSENTIENT),
+    GHAST(30, ABSTRACT_FLYING),
+    PHANTOM(63, ABSTRACT_FLYING),
+
+    ABSTRACT_AMBIENT(-1, ABSTRACT_INSENTIENT),
+    BAT(4, ABSTRACT_AMBIENT),
+
+    ABSTRACT_WATERMOB(-1, ABSTRACT_INSENTIENT),
+    SQUID(86, ABSTRACT_WATERMOB),
+    GLOW_SQUID(33, SQUID),
+
+    // Slimes
+    SLIME(80, ABSTRACT_INSENTIENT),
+    MAGMA_CUBE(48, SLIME),
+
+    // Hangable objects
+    ABSTRACT_HANGING(-1, ENTITY),
+    LEASH_KNOT(44, ABSTRACT_HANGING),
+    ITEM_FRAME(42, ABSTRACT_HANGING),
+    GLOW_ITEM_FRAME(32, ITEM_FRAME),
+    PAINTING(60, ABSTRACT_HANGING),
+
+    ABSTRACT_LIGHTNING(-1, ENTITY),
+    LIGHTNING_BOLT(45, ABSTRACT_LIGHTNING),
+
+    // Arrows
+    ABSTRACT_ARROW(-1, ENTITY),
+    ARROW(2, ABSTRACT_ARROW),
+    SPECTRAL_ARROW(84, ABSTRACT_ARROW),
+    TRIDENT(93, ABSTRACT_ARROW),
+
+    // Fireballs
+    ABSTRACT_FIREBALL(-1, ENTITY),
+    DRAGON_FIREBALL(16, ABSTRACT_FIREBALL),
+    FIREBALL(43, ABSTRACT_FIREBALL),
+    SMALL_FIREBALL(81, ABSTRACT_FIREBALL),
+    WITHER_SKULL(104, ABSTRACT_FIREBALL),
+
+    // Projectiles
+    PROJECTILE_ABSTRACT(-1, ENTITY),
+    SNOWBALL(83, PROJECTILE_ABSTRACT),
+    ENDER_PEARL(90, PROJECTILE_ABSTRACT),
+    EGG(89, PROJECTILE_ABSTRACT),
+    POTION(92, PROJECTILE_ABSTRACT),
+    EXPERIENCE_BOTTLE(91, PROJECTILE_ABSTRACT),
+
+    // Vehicles
+    MINECART_ABSTRACT(-1, ENTITY),
+    CHESTED_MINECART_ABSTRACT(-1, MINECART_ABSTRACT),
+    CHEST_MINECART(51, CHESTED_MINECART_ABSTRACT),
+    HOPPER_MINECART(54, CHESTED_MINECART_ABSTRACT),
+    MINECART(50, MINECART_ABSTRACT),
+    FURNACE_MINECART(53, MINECART_ABSTRACT),
+    COMMAND_BLOCK_MINECART(52, MINECART_ABSTRACT),
+    TNT_MINECART(56, MINECART_ABSTRACT),
+    SPAWNER_MINECART(55, MINECART_ABSTRACT),
+    BOAT(7, ENTITY);
+
+    private static final EntityType[] TYPES;
+
+    private final int id;
+    private final EntityType parent;
+
+    Entity1_17Types(int id) {
+        this.id = id;
+        this.parent = null;
+    }
+
+    Entity1_17Types(int id, EntityType parent) {
+        this.id = id;
+        this.parent = parent;
+    }
+
+    @Override
+    public int getId() {
+        return id;
+    }
+
+    @Override
+    public EntityType getParent() {
+        return parent;
+    }
+
+    static {
+        TYPES = EntityTypeUtil.toOrderedArray(values());
+    }
+
+    public static EntityType getTypeFromId(int typeId) {
+        return EntityTypeUtil.getTypeFromId(TYPES, typeId, ENTITY);
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/EntityType.java

@@ -0,0 +1,82 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.entities;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public interface EntityType {
+
+    /**
+     * Returns the entity id.
+     *
+     * @return entity id
+     */
+    int getId();
+
+    /**
+     * Returns the parent entity type if present.
+     *
+     * @return parent entity type if present
+     */
+    @Nullable EntityType getParent();
+
+    /**
+     * Returns the entity type name, not necessarily matching the Vanilla type name.
+     *
+     * @return entity type name
+     */
+    String name();
+
+    default boolean is(EntityType... types) {
+        for (EntityType type : types) {
+            if (this == type) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    default boolean is(EntityType type) {
+        return this == type;
+    }
+
+    /**
+     * Returns whether the current type is equal to the given type, or has it as a parent type.
+     *
+     * @param type entity type to check against
+     * @return true if the current type is equal to the given type, or has it as a parent type
+     */
+    default boolean isOrHasParent(EntityType type) {
+        EntityType parent = this;
+
+        do {
+            if (parent == type) {
+                return true;
+            }
+
+            parent = parent.getParent();
+        } while (parent != null);
+
+        return false;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/entities/ObjectType.java

@@ -0,0 +1,33 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.entities;
+
+/**
+ * Represents a legacy object entity type.
+ */
+public interface ObjectType {
+
+    int getId();
+
+    EntityType getType();
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/DataItem.java

@@ -0,0 +1,124 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.item;
+
+import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
+import com.google.gson.annotations.SerializedName;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.Objects;
+
+public class DataItem implements Item {
+    @SerializedName(value = "identifier", alternate = "id")
+    private int identifier;
+    private byte amount;
+    private short data;
+    private CompoundTag tag;
+
+    public DataItem() {
+    }
+
+    public DataItem(int identifier, byte amount, short data, @Nullable CompoundTag tag) {
+        this.identifier = identifier;
+        this.amount = amount;
+        this.data = data;
+        this.tag = tag;
+    }
+
+    public DataItem(Item toCopy) {
+        this(toCopy.identifier(), (byte) toCopy.amount(), toCopy.data(), toCopy.tag());
+    }
+
+    @Override
+    public int identifier() {
+        return identifier;
+    }
+
+    @Override
+    public void setIdentifier(int identifier) {
+        this.identifier = identifier;
+    }
+
+    @Override
+    public int amount() {
+        return amount;
+    }
+
+    @Override
+    public void setAmount(int amount) {
+        if (amount > Byte.MAX_VALUE || amount < Byte.MIN_VALUE) {
+            throw new IllegalArgumentException("Invalid item amount: " + amount);
+        }
+        this.amount = (byte) amount;
+    }
+
+    @Override
+    public short data() {
+        return data;
+    }
+
+    @Override
+    public void setData(short data) {
+        this.data = data;
+    }
+
+    @Override
+    public @Nullable CompoundTag tag() {
+        return tag;
+    }
+
+    @Override
+    public void setTag(@Nullable CompoundTag tag) {
+        this.tag = tag;
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        DataItem item = (DataItem) o;
+        if (identifier != item.identifier) return false;
+        if (amount != item.amount) return false;
+        if (data != item.data) return false;
+        return Objects.equals(tag, item.tag);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = identifier;
+        result = 31 * result + (int) amount;
+        result = 31 * result + (int) data;
+        result = 31 * result + (tag != null ? tag.hashCode() : 0);
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "Item{" +
+                "identifier=" + identifier +
+                ", amount=" + amount +
+                ", data=" + data +
+                ", tag=" + tag +
+                '}';
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/Item.java

@@ -0,0 +1,90 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.item;
+
+import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public interface Item {
+
+    /**
+     * Returns the item identifier.
+     *
+     * @return item identifier
+     */
+    int identifier();
+
+    /**
+     * Sets the item identifier.
+     *
+     * @param identifier item identifier
+     */
+    void setIdentifier(int identifier);
+
+    /**
+     * Returns the item amount.
+     *
+     * @return item amount
+     */
+    int amount();
+
+    /**
+     * Returns the item amount.
+     *
+     * @param amount item amount
+     */
+    void setAmount(int amount);
+
+    /**
+     * Returns the item data. Always 0 for 1.13+ items.
+     *
+     * @return item data
+     */
+    default short data() {
+        return 0;
+    }
+
+    /**
+     * Sets the item data used in versions before 1.13.
+     *
+     * @param data item data
+     * @throws UnsupportedOperationException if the item implementation does not store data
+     */
+    default void setData(short data) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Returns the item compound tag if present.
+     *
+     * @return item tag
+     */
+    @Nullable CompoundTag tag();
+
+    /**
+     * Sets the item compound tag.
+     *
+     * @param tag item tag
+     */
+    void setTag(@Nullable CompoundTag tag);
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/metadata/MetaType.java

@@ -0,0 +1,42 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.metadata;
+
+import com.viaversion.viaversion.api.type.Type;
+
+public interface MetaType {
+
+    /**
+     * Get the write/read type
+     *
+     * @return Type instance
+     */
+    Type type();
+
+    /**
+     * Get type id from the specific MetaDataType
+     *
+     * @return Type id as an integer
+     */
+    int typeId();
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/metadata/Metadata.java

@@ -0,0 +1,144 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.metadata;
+
+import com.google.common.base.Preconditions;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.util.Objects;
+
+public final class Metadata {
+    private int id;
+    private MetaType metaType;
+    private Object value;
+
+    /**
+     * Creates a new metadata instance.
+     *
+     * @param id       metadata index
+     * @param metaType metadata type
+     * @param value    value if present
+     * @throws IllegalArgumentException if the value and metaType are incompatible
+     */
+    public Metadata(int id, MetaType metaType, @Nullable Object value) {
+        this.id = id;
+        this.metaType = metaType;
+        this.value = checkValue(metaType, value);
+    }
+
+    public int id() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public MetaType metaType() {
+        return metaType;
+    }
+
+    /**
+     * Sets the metadata type if compatible with the current value.
+     *
+     * @param metaType metadata type
+     * @throws IllegalArgumentException if the metadata type and current value are incompatible
+     * @see #setTypeAndValue(MetaType, Object)
+     */
+    public void setMetaType(MetaType metaType) {
+        checkValue(metaType, this.value);
+        this.metaType = metaType;
+    }
+
+    public @Nullable <T> T value() {
+        return (T) value;
+    }
+
+    public @Nullable Object getValue() {
+        return value;
+    }
+
+    /**
+     * Sets the metadata value if compatible with the current meta type.
+     *
+     * @param value value
+     * @throws IllegalArgumentException if the value and current metaType are incompatible
+     * @see #setTypeAndValue(MetaType, Object)
+     */
+    public void setValue(@Nullable Object value) {
+        this.value = checkValue(this.metaType, value);
+    }
+
+    /**
+     * Sets metadata type and value.
+     *
+     * @param metaType metadata type
+     * @param value    value
+     * @throws IllegalArgumentException if the value and metaType are incompatible
+     */
+    public void setTypeAndValue(MetaType metaType, @Nullable Object value) {
+        this.value = checkValue(metaType, value);
+        this.metaType = metaType;
+    }
+
+    private Object checkValue(MetaType metaType, @Nullable Object value) {
+        Preconditions.checkNotNull(metaType);
+        if (value != null && !metaType.type().getOutputClass().isAssignableFrom(value.getClass())) {
+            throw new IllegalArgumentException("Metadata value and metaType are incompatible. Type=" + metaType
+                    + ", value=" + (value != null ? value + " (" + value.getClass().getSimpleName() + ")" : "null"));
+        }
+        return value;
+    }
+
+    @Deprecated
+    public void setMetaTypeUnsafe(MetaType type) {
+        this.metaType = type;
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Metadata metadata = (Metadata) o;
+        if (id != metadata.id) return false;
+        if (metaType != metaType) return false;
+        return Objects.equals(value, metadata.value);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = id;
+        result = 31 * result + metaType.hashCode();
+        result = 31 * result + (value != null ? value.hashCode() : 0);
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "Metadata{" +
+                "id=" + id +
+                ", metaType=" + metaType +
+                ", value=" + value +
+                '}';
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/metadata/types/MetaType1_12.java

@@ -0,0 +1,65 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.metadata.types;
+
+import com.viaversion.viaversion.api.minecraft.metadata.MetaType;
+import com.viaversion.viaversion.api.type.Type;
+
+public enum MetaType1_12 implements MetaType {
+    Byte(0, Type.BYTE),
+    VarInt(1, Type.VAR_INT),
+    Float(2, Type.FLOAT),
+    String(3, Type.STRING),
+    Chat(4, Type.COMPONENT),
+    Slot(5, Type.ITEM),
+    Boolean(6, Type.BOOLEAN),
+    Vector3F(7, Type.ROTATION),
+    Position(8, Type.POSITION),
+    OptPosition(9, Type.OPTIONAL_POSITION),
+    Direction(10, Type.VAR_INT),
+    OptUUID(11, Type.OPTIONAL_UUID),
+    BlockID(12, Type.VAR_INT),
+    NBTTag(13, Type.NBT);
+
+    private final int typeID;
+    private final Type type;
+
+    MetaType1_12(int typeID, Type type) {
+        this.typeID = typeID;
+        this.type = type;
+    }
+
+    public static MetaType1_12 byId(int id) {
+        return values()[id];
+    }
+
+    @Override
+    public int typeId() {
+        return typeID;
+    }
+
+    @Override
+    public Type type() {
+        return type;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/metadata/types/MetaType1_13.java

@@ -0,0 +1,68 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.metadata.types;
+
+import com.viaversion.viaversion.api.minecraft.metadata.MetaType;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.types.version.Types1_13;
+
+public enum MetaType1_13 implements MetaType {
+    Byte(0, Type.BYTE),
+    VarInt(1, Type.VAR_INT),
+    Float(2, Type.FLOAT),
+    String(3, Type.STRING),
+    Chat(4, Type.COMPONENT),
+    OptChat(5, Type.OPTIONAL_COMPONENT),
+    Slot(6, Type.FLAT_ITEM),
+    Boolean(7, Type.BOOLEAN),
+    Vector3F(8, Type.ROTATION),
+    Position(9, Type.POSITION),
+    OptPosition(10, Type.OPTIONAL_POSITION),
+    Direction(11, Type.VAR_INT),
+    OptUUID(12, Type.OPTIONAL_UUID),
+    BlockID(13, Type.VAR_INT),
+    NBTTag(14, Type.NBT),
+    PARTICLE(15, Types1_13.PARTICLE);
+
+    private final int typeID;
+    private final Type type;
+
+    MetaType1_13(int typeID, Type type) {
+        this.typeID = typeID;
+        this.type = type;
+    }
+
+    public static MetaType1_13 byId(int id) {
+        return values()[id];
+    }
+
+    @Override
+    public int typeId() {
+        return typeID;
+    }
+
+    @Override
+    public Type type() {
+        return type;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/metadata/types/MetaType1_13_2.java

@@ -0,0 +1,68 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.metadata.types;
+
+import com.viaversion.viaversion.api.minecraft.metadata.MetaType;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.types.version.Types1_13_2;
+
+public enum MetaType1_13_2 implements MetaType {
+    Byte(0, Type.BYTE),
+    VarInt(1, Type.VAR_INT),
+    Float(2, Type.FLOAT),
+    String(3, Type.STRING),
+    Chat(4, Type.COMPONENT),
+    OptChat(5, Type.OPTIONAL_COMPONENT),
+    Slot(6, Type.FLAT_VAR_INT_ITEM),
+    Boolean(7, Type.BOOLEAN),
+    Vector3F(8, Type.ROTATION),
+    Position(9, Type.POSITION),
+    OptPosition(10, Type.OPTIONAL_POSITION),
+    Direction(11, Type.VAR_INT),
+    OptUUID(12, Type.OPTIONAL_UUID),
+    BlockID(13, Type.VAR_INT),
+    NBTTag(14, Type.NBT),
+    PARTICLE(15, Types1_13_2.PARTICLE);
+
+    private final int typeID;
+    private final Type type;
+
+    MetaType1_13_2(int typeID, Type type) {
+        this.typeID = typeID;
+        this.type = type;
+    }
+
+    public static MetaType1_13_2 byId(int id) {
+        return values()[id];
+    }
+
+    @Override
+    public int typeId() {
+        return typeID;
+    }
+
+    @Override
+    public Type type() {
+        return type;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/metadata/types/MetaType1_14.java

@@ -0,0 +1,71 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.metadata.types;
+
+import com.viaversion.viaversion.api.minecraft.metadata.MetaType;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.types.version.Types1_14;
+
+public enum MetaType1_14 implements MetaType {
+    Byte(0, Type.BYTE),
+    VarInt(1, Type.VAR_INT),
+    Float(2, Type.FLOAT),
+    String(3, Type.STRING),
+    Chat(4, Type.COMPONENT),
+    OptChat(5, Type.OPTIONAL_COMPONENT),
+    Slot(6, Type.FLAT_VAR_INT_ITEM),
+    Boolean(7, Type.BOOLEAN),
+    Vector3F(8, Type.ROTATION),
+    Position(9, Type.POSITION1_14),
+    OptPosition(10, Type.OPTIONAL_POSITION_1_14),
+    Direction(11, Type.VAR_INT),
+    OptUUID(12, Type.OPTIONAL_UUID),
+    BlockID(13, Type.VAR_INT),
+    NBTTag(14, Type.NBT),
+    PARTICLE(15, Types1_14.PARTICLE),
+    VillagerData(16, Type.VILLAGER_DATA),
+    OptVarInt(17, Type.OPTIONAL_VAR_INT),
+    Pose(18, Type.VAR_INT);
+
+    private final int typeID;
+    private final Type type;
+
+    MetaType1_14(int typeID, Type type) {
+        this.typeID = typeID;
+        this.type = type;
+    }
+
+    public static MetaType1_14 byId(int id) {
+        return values()[id];
+    }
+
+    @Override
+    public int typeId() {
+        return typeID;
+    }
+
+    @Override
+    public Type type() {
+        return type;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/metadata/types/MetaType1_17.java

@@ -0,0 +1,72 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.metadata.types;
+
+import com.viaversion.viaversion.api.minecraft.metadata.MetaType;
+import com.viaversion.viaversion.api.type.Type;
+import com.viaversion.viaversion.api.type.types.version.Types1_17;
+
+public enum MetaType1_17 implements MetaType {
+    BYTE(0, Type.BYTE),
+    VAR_INT(1, Type.VAR_INT),
+    FLOAT(2, Type.FLOAT),
+    STRING(3, Type.STRING),
+    COMPONENT(4, Type.COMPONENT),
+    OPT_COMPONENT(5, Type.OPTIONAL_COMPONENT),
+    ITEM(6, Type.FLAT_VAR_INT_ITEM),
+    BOOLEAN(7, Type.BOOLEAN),
+    ROTATION(8, Type.ROTATION),
+    POSITION(9, Type.POSITION1_14),
+    OPT_POSITION(10, Type.OPTIONAL_POSITION_1_14),
+    DIRECTION(11, Type.VAR_INT),
+    OPT_UUID(12, Type.OPTIONAL_UUID),
+    BLOCK_STATE(13, Type.VAR_INT),
+    NBT(14, Type.NBT),
+    PARTICLE(15, Types1_17.PARTICLE),
+    VILLAGER_DATA(16, Type.VILLAGER_DATA),
+    OPT_VAR_INT(17, Type.OPTIONAL_VAR_INT),
+    POSE(18, Type.VAR_INT);
+
+    private static final MetaType1_17[] VALUES = values();
+    private final int typeId;
+    private final Type type;
+
+    MetaType1_17(int typeId, Type type) {
+        this.typeId = typeId;
+        this.type = type;
+    }
+
+    public static MetaType1_17 byId(int id) {
+        return VALUES[id];
+    }
+
+    @Override
+    public int typeId() {
+        return typeId;
+    }
+
+    @Override
+    public Type type() {
+        return type;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/metadata/types/MetaType1_8.java

@@ -0,0 +1,61 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.metadata.types;
+
+import com.viaversion.viaversion.api.minecraft.metadata.MetaType;
+import com.viaversion.viaversion.api.type.Type;
+
+public enum MetaType1_8 implements MetaType {
+    Byte(0, Type.BYTE),
+    Short(1, Type.SHORT),
+    Int(2, Type.INT),
+    Float(3, Type.FLOAT),
+    String(4, Type.STRING),
+    Slot(5, Type.ITEM),
+    Position(6, Type.VECTOR),
+    Rotation(7, Type.ROTATION),
+    @Deprecated
+    NonExistent(-1, Type.NOTHING);
+
+    private final int typeID;
+    private final Type type;
+
+    MetaType1_8(int typeID, Type type) {
+        this.typeID = typeID;
+        this.type = type;
+    }
+
+    public static MetaType1_8 byId(int id) {
+        return values()[id];
+    }
+
+    @Override
+    public int typeId() {
+        return typeID;
+    }
+
+    @Override
+    public Type type() {
+        return type;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/metadata/types/MetaType1_9.java

@@ -0,0 +1,64 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.minecraft.metadata.types;
+
+import com.viaversion.viaversion.api.minecraft.metadata.MetaType;
+import com.viaversion.viaversion.api.type.Type;
+
+public enum MetaType1_9 implements MetaType {
+    Byte(0, Type.BYTE),
+    VarInt(1, Type.VAR_INT),
+    Float(2, Type.FLOAT),
+    String(3, Type.STRING),
+    Chat(4, Type.COMPONENT),
+    Slot(5, Type.ITEM),
+    Boolean(6, Type.BOOLEAN),
+    Vector3F(7, Type.ROTATION),
+    Position(8, Type.POSITION),
+    OptPosition(9, Type.OPTIONAL_POSITION),
+    Direction(10, Type.VAR_INT),
+    OptUUID(11, Type.OPTIONAL_UUID),
+    BlockID(12, Type.VAR_INT);
+
+    private final int typeID;
+    private final Type type;
+
+    MetaType1_9(int typeID, Type type) {
+        this.typeID = typeID;
+        this.type = type;
+    }
+
+    public static MetaType1_9 byId(int id) {
+        return values()[id];
+    }
+
+    @Override
+    public int typeId() {
+        return typeID;
+    }
+
+    @Override
+    public Type type() {
+        return type;
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/nbt/BinaryTagIO.java

@@ -21,11 +21,10 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-package us.myles.ViaVersion.api.minecraft.nbt;
+package com.viaversion.viaversion.api.minecraft.nbt;
 
-import com.github.steveice10.opennbt.tag.TagRegistry;
 import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
-import org.jetbrains.annotations.NotNull;
+import org.checkerframework.checker.nullness.qual.NonNull;
 
 import java.io.BufferedInputStream;
 import java.io.DataInput;
@@ -54,8 +53,7 @@ public final class BinaryTagIO {
      * @return the compound tag
      * @throws IOException if an exception was encountered while reading a compound tag
      */
-    @NotNull
-    public static CompoundTag readPath(final @NotNull Path path) throws IOException {
+    public static @NonNull CompoundTag readPath(final @NonNull Path path) throws IOException {
         return readInputStream(Files.newInputStream(path));
     }
 
@@ -66,8 +64,7 @@ public final class BinaryTagIO {
      * @return the compound tag
      * @throws IOException if an exception was encountered while reading a compound tag
      */
-    @NotNull
-    public static CompoundTag readInputStream(final @NotNull InputStream input) throws IOException {
+    public static @NonNull CompoundTag readInputStream(final @NonNull InputStream input) throws IOException {
         try (final DataInputStream dis = new DataInputStream(input)) {
             return readDataInput(dis);
         }
@@ -80,8 +77,7 @@ public final class BinaryTagIO {
      * @return the compound tag
      * @throws IOException if an exception was encountered while reading a compound tag
      */
-    @NotNull
-    public static CompoundTag readCompressedPath(final @NotNull Path path) throws IOException {
+    public static @NonNull CompoundTag readCompressedPath(final @NonNull Path path) throws IOException {
         return readCompressedInputStream(Files.newInputStream(path));
     }
 
@@ -92,8 +88,7 @@ public final class BinaryTagIO {
      * @return the compound tag
      * @throws IOException if an exception was encountered while reading a compound tag
      */
-    @NotNull
-    public static CompoundTag readCompressedInputStream(final @NotNull InputStream input) throws IOException {
+    public static @NonNull CompoundTag readCompressedInputStream(final @NonNull InputStream input) throws IOException {
         try (final DataInputStream dis = new DataInputStream(new BufferedInputStream(new GZIPInputStream(input)))) {
             return readDataInput(dis);
         }
@@ -106,15 +101,14 @@ public final class BinaryTagIO {
      * @return the compound tag
      * @throws IOException if an exception was encountered while reading a compound tag
      */
-    @NotNull
-    public static CompoundTag readDataInput(final @NotNull DataInput input) throws IOException {
+    public static @NonNull CompoundTag readDataInput(final @NonNull DataInput input) throws IOException {
         byte type = input.readByte();
-        if (type != TagRegistry.getIdFor(CompoundTag.class)) {
+        if (type != CompoundTag.ID) {
             throw new IOException(String.format("Expected root tag to be a CompoundTag, was %s", type));
         }
         input.skipBytes(input.readUnsignedShort()); // read empty name
 
-        final CompoundTag compoundTag = new CompoundTag("");
+        final CompoundTag compoundTag = new CompoundTag();
         compoundTag.read(input);
         return compoundTag;
     }
@@ -126,7 +120,7 @@ public final class BinaryTagIO {
      * @param path the path
      * @throws IOException if an exception was encountered while writing the compound tag
      */
-    public static void writePath(final @NotNull CompoundTag tag, final @NotNull Path path) throws IOException {
+    public static void writePath(final @NonNull CompoundTag tag, final @NonNull Path path) throws IOException {
         writeOutputStream(tag, Files.newOutputStream(path));
     }
 
@@ -137,7 +131,7 @@ public final class BinaryTagIO {
      * @param output the output stream
      * @throws IOException if an exception was encountered while writing the compound tag
      */
-    public static void writeOutputStream(final @NotNull CompoundTag tag, final @NotNull OutputStream output) throws IOException {
+    public static void writeOutputStream(final @NonNull CompoundTag tag, final @NonNull OutputStream output) throws IOException {
         try (final DataOutputStream dos = new DataOutputStream(output)) {
             writeDataOutput(tag, dos);
         }
@@ -150,7 +144,7 @@ public final class BinaryTagIO {
      * @param path the path
      * @throws IOException if an exception was encountered while writing the compound tag
      */
-    public static void writeCompressedPath(final @NotNull CompoundTag tag, final @NotNull Path path) throws IOException {
+    public static void writeCompressedPath(final @NonNull CompoundTag tag, final @NonNull Path path) throws IOException {
         writeCompressedOutputStream(tag, Files.newOutputStream(path));
     }
 
@@ -161,7 +155,7 @@ public final class BinaryTagIO {
      * @param output the output stream
      * @throws IOException if an exception was encountered while writing the compound tag
      */
-    public static void writeCompressedOutputStream(final @NotNull CompoundTag tag, final @NotNull OutputStream output) throws IOException {
+    public static void writeCompressedOutputStream(final @NonNull CompoundTag tag, final @NonNull OutputStream output) throws IOException {
         try (final DataOutputStream dos = new DataOutputStream(new GZIPOutputStream(output))) {
             writeDataOutput(tag, dos);
         }
@@ -174,8 +168,8 @@ public final class BinaryTagIO {
      * @param output the output
      * @throws IOException if an exception was encountered while writing the compound tag
      */
-    public static void writeDataOutput(final @NotNull CompoundTag tag, final @NotNull DataOutput output) throws IOException {
-        output.writeByte(TagRegistry.getIdFor(CompoundTag.class));
+    public static void writeDataOutput(final @NonNull CompoundTag tag, final @NonNull DataOutput output) throws IOException {
+        output.writeByte(CompoundTag.ID);
         output.writeUTF(""); // write empty name
         tag.write(output);
     }
@@ -187,8 +181,7 @@ public final class BinaryTagIO {
      * @return the compound tag
      * @throws IOException if an exception was encountered while reading a compound tag
      */
-    @NotNull
-    public static CompoundTag readString(final @NotNull String input) throws IOException {
+    public static @NonNull CompoundTag readString(final @NonNull String input) throws IOException {
         try {
             final CharBuffer buffer = new CharBuffer(input);
             final TagStringReader parser = new TagStringReader(buffer);
@@ -209,8 +202,7 @@ public final class BinaryTagIO {
      * @return the string
      * @throws IOException if an exception was encountered while writing the compound tag
      */
-    @NotNull
-    public static String writeString(final @NotNull CompoundTag tag) throws IOException {
+    public static @NonNull String writeString(final @NonNull CompoundTag tag) throws IOException {
         final StringBuilder sb = new StringBuilder();
         try (final TagStringWriter emit = new TagStringWriter(sb)) {
             emit.writeTag(tag);

api/src/main/java/com/viaversion/viaversion/api/minecraft/nbt/CharBuffer.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-package us.myles.ViaVersion.api.minecraft.nbt;
+package com.viaversion.viaversion.api.minecraft.nbt;
 
 /* package */ final class CharBuffer {
     private final CharSequence sequence;

api/src/main/java/com/viaversion/viaversion/api/minecraft/nbt/StringTagParseException.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-package us.myles.ViaVersion.api.minecraft.nbt;
+package com.viaversion.viaversion.api.minecraft.nbt;
 
 import java.io.IOException;
 

api/src/main/java/com/viaversion/viaversion/api/minecraft/nbt/TagStringReader.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-package us.myles.ViaVersion.api.minecraft.nbt;
+package com.viaversion.viaversion.api.minecraft.nbt;
 
 import com.github.steveice10.opennbt.tag.builtin.ByteArrayTag;
 import com.github.steveice10.opennbt.tag.builtin.ByteTag;
@@ -33,11 +33,11 @@ import com.github.steveice10.opennbt.tag.builtin.IntTag;
 import com.github.steveice10.opennbt.tag.builtin.ListTag;
 import com.github.steveice10.opennbt.tag.builtin.LongArrayTag;
 import com.github.steveice10.opennbt.tag.builtin.LongTag;
+import com.github.steveice10.opennbt.tag.builtin.NumberTag;
 import com.github.steveice10.opennbt.tag.builtin.ShortTag;
 import com.github.steveice10.opennbt.tag.builtin.StringTag;
 import com.github.steveice10.opennbt.tag.builtin.Tag;
 
-import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.IntStream;
@@ -46,25 +46,15 @@ import java.util.stream.IntStream;
  * See https://github.com/KyoriPowered/adventure.
  */
 /* package */ final class TagStringReader {
-    private static final Field NAME_FIELD = getNameField();
     private final CharBuffer buffer;
 
-    private static Field getNameField() {
-        try {
-            return Tag.class.getDeclaredField("name");
-        } catch (NoSuchFieldException e) {
-            e.printStackTrace();
-            throw new IllegalArgumentException(e);
-        }
-    }
-
     public TagStringReader(final CharBuffer buffer) {
         this.buffer = buffer;
     }
 
     public CompoundTag compound() throws StringTagParseException {
         this.buffer.expect(Tokens.COMPOUND_BEGIN);
-        final CompoundTag compoundTag = new CompoundTag("");
+        final CompoundTag compoundTag = new CompoundTag();
         if (this.buffer.peek() == Tokens.COMPOUND_END) {
             this.buffer.take();
             return compoundTag;
@@ -73,17 +63,7 @@ import java.util.stream.IntStream;
         while (this.buffer.hasMore()) {
             final String key = this.key();
             final Tag tag = this.tag();
-            // Doesn't get around this with the steveice lib :/
-            try {
-                if (!NAME_FIELD.isAccessible()) {
-                    NAME_FIELD.setAccessible(true);
-                }
-                NAME_FIELD.set(tag, key);
-            } catch (IllegalAccessException e) {
-                throw new IllegalArgumentException(e);
-            }
-
-            compoundTag.put(tag);
+            compoundTag.put(key, tag);
             if (this.separatorOrCompleteWith(Tokens.COMPOUND_END)) {
                 return compoundTag;
             }
@@ -92,10 +72,15 @@ import java.util.stream.IntStream;
     }
 
     public ListTag list() throws StringTagParseException {
-        final ListTag listTag = new ListTag("");
+        final ListTag listTag = new ListTag();
         this.buffer.expect(Tokens.ARRAY_BEGIN);
         final boolean prefixedIndex = this.buffer.peek() == '0' && this.buffer.peek(1) == ':';
         while (this.buffer.hasMore()) {
+            if (this.buffer.peek() == Tokens.ARRAY_END) {
+                this.buffer.advance();
+                return listTag;
+            }
+
             if (prefixedIndex) {
                 this.buffer.takeUntil(':');
             }
@@ -121,11 +106,11 @@ import java.util.stream.IntStream;
                 .expect(Tokens.ARRAY_SIGNATURE_SEPARATOR);
 
         if (elementType == Tokens.TYPE_BYTE) {
-            return new ByteArrayTag("", this.byteArray());
+            return new ByteArrayTag(this.byteArray());
         } else if (elementType == Tokens.TYPE_INT) {
-            return new IntArrayTag("", this.intArray());
+            return new IntArrayTag(this.intArray());
         } else if (elementType == Tokens.TYPE_LONG) {
-            return new LongArrayTag("", this.longArray());
+            return new LongArrayTag(this.longArray());
         } else {
             throw this.buffer.makeError("Type " + elementType + " is not a valid element type in an array!");
         }
@@ -159,7 +144,7 @@ import java.util.stream.IntStream;
             if (!(value instanceof IntTag)) {
                 throw this.buffer.makeError("All elements of an int array must be ints!");
             }
-            builder.add(((IntTag) value).getValue());
+            builder.add(((NumberTag) value).asInt());
             if (this.separatorOrCompleteWith(Tokens.ARRAY_END)) {
                 return builder.build().toArray();
             }
@@ -221,7 +206,7 @@ import java.util.stream.IntStream;
             case Tokens.DOUBLE_QUOTE:
                 // definitely a string tag
                 this.buffer.advance();
-                return new StringTag("", unescape(this.buffer.takeUntil(startToken).toString()));
+                return new StringTag(unescape(this.buffer.takeUntil(startToken).toString()));
             default: // scalar
                 return this.scalar();
         }
@@ -246,19 +231,19 @@ import java.util.stream.IntStream;
                         switch (Character.toUpperCase(current)) { // try to read and return as a number
                             // case Tokens.TYPE_INTEGER: // handled below, ints are ~special~
                             case Tokens.TYPE_BYTE:
-                                result = new ByteTag("", Byte.parseByte(builder.toString()));
+                                result = new ByteTag(Byte.parseByte(builder.toString()));
                                 break;
                             case Tokens.TYPE_SHORT:
-                                result = new ShortTag("", (Short.parseShort(builder.toString())));
+                                result = new ShortTag(Short.parseShort(builder.toString()));
                                 break;
                             case Tokens.TYPE_LONG:
-                                result = new LongTag("", (Long.parseLong(builder.toString())));
+                                result = new LongTag(Long.parseLong(builder.toString()));
                                 break;
                             case Tokens.TYPE_FLOAT:
-                                result = new FloatTag("", (Float.parseFloat(builder.toString())));
+                                result = new FloatTag(Float.parseFloat(builder.toString()));
                                 break;
                             case Tokens.TYPE_DOUBLE:
-                                result = new DoubleTag("", (Double.parseDouble(builder.toString())));
+                                result = new DoubleTag(Double.parseDouble(builder.toString()));
                                 break;
                         }
                     } catch (final NumberFormatException ex) {
@@ -283,12 +268,12 @@ import java.util.stream.IntStream;
         final String built = builder.toString();
         if (possiblyNumeric) {
             try {
-                return new IntTag("", Integer.parseInt(built));
+                return new IntTag(Integer.parseInt(built));
             } catch (final NumberFormatException ex) {
                 // ignore
             }
         }
-        return new StringTag("", built);
+        return new StringTag(built);
 
     }
 
@@ -298,6 +283,10 @@ import java.util.stream.IntStream;
             return true;
         }
         this.buffer.expect(Tokens.VALUE_SEPARATOR);
+        if (this.buffer.skipWhitespace().peek() == endCharacter) {
+            this.buffer.take();
+            return true;
+        }
         return false;
     }
 

api/src/main/java/com/viaversion/viaversion/api/minecraft/nbt/TagStringWriter.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-package us.myles.ViaVersion.api.minecraft.nbt;
+package com.viaversion.viaversion.api.minecraft.nbt;
 
 import com.github.steveice10.opennbt.tag.builtin.ByteArrayTag;
 import com.github.steveice10.opennbt.tag.builtin.ByteTag;
@@ -39,6 +39,7 @@ import com.github.steveice10.opennbt.tag.builtin.Tag;
 
 import java.io.IOException;
 import java.io.Writer;
+import java.util.Map;
 
 /**
  * See https://github.com/KyoriPowered/adventure.
@@ -72,17 +73,17 @@ import java.io.Writer;
         } else if (tag instanceof StringTag) {
             return this.value(((StringTag) tag).getValue(), Tokens.EOF);
         } else if (tag instanceof ByteTag) {
-            return this.value(Byte.toString(((ByteTag) tag).getValue()), Tokens.TYPE_BYTE);
+            return this.value(Byte.toString(((ByteTag) tag).asByte()), Tokens.TYPE_BYTE);
         } else if (tag instanceof ShortTag) {
-            return this.value(Short.toString(((ShortTag) tag).getValue()), Tokens.TYPE_SHORT);
+            return this.value(Short.toString(((ShortTag) tag).asShort()), Tokens.TYPE_SHORT);
         } else if (tag instanceof IntTag) {
-            return this.value(Integer.toString(((IntTag) tag).getValue()), Tokens.TYPE_INT);
+            return this.value(Integer.toString(((IntTag) tag).asInt()), Tokens.TYPE_INT);
         } else if (tag instanceof LongTag) {
-            return this.value(Long.toString(((LongTag) tag).getValue()), Tokens.TYPE_LONG);
+            return this.value(Long.toString(((LongTag) tag).asLong()), Tokens.TYPE_LONG);
         } else if (tag instanceof FloatTag) {
-            return this.value(Float.toString(((FloatTag) tag).getValue()), Tokens.TYPE_FLOAT);
+            return this.value(Float.toString(((FloatTag) tag).asFloat()), Tokens.TYPE_FLOAT);
         } else if (tag instanceof DoubleTag) {
-            return this.value(Double.toString(((DoubleTag) tag).getValue()), Tokens.TYPE_DOUBLE);
+            return this.value(Double.toString(((DoubleTag) tag).asDouble()), Tokens.TYPE_DOUBLE);
         } else {
             throw new IOException("Unknown tag type: " + tag.getClass().getSimpleName());
             // unknown!
@@ -91,9 +92,9 @@ import java.io.Writer;
 
     private TagStringWriter writeCompound(final CompoundTag tag) throws IOException {
         this.beginCompound();
-        for (Tag t : tag) {
-            this.key(t.getName());
-            this.writeTag(t);
+        for (Map.Entry<String, Tag> entry : tag.entrySet()) {
+            this.key(entry.getKey());
+            this.writeTag(entry.getValue());
         }
         this.endCompound();
         return this;

api/src/main/java/com/viaversion/viaversion/api/minecraft/nbt/Tokens.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-package us.myles.ViaVersion.api.minecraft.nbt;
+package com.viaversion.viaversion.api.minecraft.nbt;
 
 /**
  * See https://github.com/KyoriPowered/adventure.

api/src/main/java/com/viaversion/viaversion/api/platform/PlatformTask.java

@@ -0,0 +1,46 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.platform;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/**
+ * @param <T> task type
+ */
+public interface PlatformTask<T> {
+
+    /**
+     * Returns the actual object represented by this task/task id.
+     * Null if task cannot be instantly tracked.
+     *
+     * @return platform based object, or null if not tracked/cancellable
+     */
+    @Nullable T getObject();
+
+    /**
+     * Cancels the task.
+     *
+     * @throws IllegalArgumentException if the task is not cancellable
+     */
+    void cancel();
+}

api/src/main/java/com/viaversion/viaversion/api/platform/UnsupportedSoftware.java

@@ -0,0 +1,47 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.platform;
+
+public interface UnsupportedSoftware {
+
+    /**
+     * Returns the software name.
+     *
+     * @return software name
+     */
+    String getName();
+
+    /**
+     * Returns the reason for being unsupported by Via.
+     *
+     * @return reason for being unsupported
+     */
+    String getReason();
+
+    /**
+     * Returns whether the unsupported software is present.
+     *
+     * @return true if the unsupported software is found
+     */
+    boolean findMatch();
+}

api/src/main/java/com/viaversion/viaversion/api/platform/ViaInjector.java

@@ -0,0 +1,96 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.platform;
+
+import com.google.gson.JsonObject;
+import it.unimi.dsi.fastutil.ints.IntSortedSet;
+import it.unimi.dsi.fastutil.ints.IntSortedSets;
+
+public interface ViaInjector {
+
+    /**
+     * Inject into the current Platform
+     *
+     * @throws Exception If there is an error with injecting
+     */
+    void inject() throws Exception;
+
+    /**
+     * Uninject into the current Platform
+     *
+     * @throws Exception If there is an error with uninjecting
+     */
+    void uninject() throws Exception;
+
+    /**
+     * Returns true if the protocol version cannot be used in the early init.
+     * Namely, this returns true for forks of Vanilla without extra API to get the protocol version.
+     *
+     * @return true if the protocol version cannot be used in the early init
+     */
+    default boolean lateProtocolVersionSetting() {
+        return false;
+    }
+
+    /**
+     * Returns the server protocol version.
+     * For proxies, this returns the lowest supported protocol version.
+     *
+     * @return server protocol version
+     * @throws Exception if there is an error with getting this info, eg. not binded
+     * @see ViaPlatform#isProxy()
+     */
+    int getServerProtocolVersion() throws Exception;
+
+    /**
+     * Returns the supported server protocol versions.
+     *
+     * @return server protocol versions
+     * @throws Exception if there is an error with getting this info, eg. not binded
+     * @see ViaPlatform#isProxy()
+     */
+    default IntSortedSet getServerProtocolVersions() throws Exception {
+        return IntSortedSets.singleton(getServerProtocolVersion());
+    }
+
+    /**
+     * Get the name of the encoder for then netty pipeline for this platform.
+     *
+     * @return The name
+     */
+    String getEncoderName();
+
+    /**
+     * Get the name of the decoder for then netty pipeline for this platform.
+     *
+     * @return The name
+     */
+    String getDecoderName();
+
+    /**
+     * Get any relevant data for debugging injection issues.
+     *
+     * @return JSONObject containing the data
+     */
+    JsonObject getDump();
+}

api/src/main/java/com/viaversion/viaversion/api/platform/ViaPlatform.java

@@ -1,15 +1,37 @@
-package us.myles.ViaVersion.api.platform;
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.platform;
 
 import com.google.gson.JsonObject;
-import us.myles.ViaVersion.api.Via;
-import us.myles.ViaVersion.api.ViaAPI;
-import us.myles.ViaVersion.api.ViaVersionConfig;
-import us.myles.ViaVersion.api.command.ViaCommandSender;
-import us.myles.ViaVersion.api.configuration.ConfigurationProvider;
-import us.myles.ViaVersion.api.data.UserConnection;
-import us.myles.ViaVersion.protocols.base.ProtocolInfo;
+import com.viaversion.viaversion.api.ViaAPI;
+import com.viaversion.viaversion.api.command.ViaCommandSender;
+import com.viaversion.viaversion.api.configuration.ConfigurationProvider;
+import com.viaversion.viaversion.api.configuration.ViaVersionConfig;
+import com.viaversion.viaversion.api.connection.UserConnection;
 
 import java.io.File;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.UUID;
 import java.util.logging.Logger;
 
@@ -63,7 +85,7 @@ public interface ViaPlatform<T> {
      * @param runnable The task to run
      * @return The Task ID
      */
-    TaskId runAsync(Runnable runnable);
+    PlatformTask runAsync(Runnable runnable);
 
     /**
      * Run a task Sync
@@ -71,7 +93,7 @@ public interface ViaPlatform<T> {
      * @param runnable The task to run
      * @return The Task ID
      */
-    TaskId runSync(Runnable runnable);
+    PlatformTask runSync(Runnable runnable);
 
     /**
      * Run a task Sync after a interval
@@ -81,7 +103,7 @@ public interface ViaPlatform<T> {
      * @param ticks    The interval to run it after
      * @return The Task ID
      */
-    TaskId runSync(Runnable runnable, Long ticks);
+    PlatformTask runSync(Runnable runnable, long ticks);
 
     /**
      * Run a task at a repeating interval.
@@ -91,14 +113,7 @@ public interface ViaPlatform<T> {
      * @param ticks    The interval to run it at
      * @return The Task ID
      */
-    TaskId runRepeatingSync(Runnable runnable, Long ticks);
-
-    /**
-     * Cancel a task
-     *
-     * @param taskId The task ID to cancel
-     */
-    void cancelTask(TaskId taskId);
+    PlatformTask runRepeatingSync(Runnable runnable, long ticks);
 
     /**
      * Get the online players
@@ -127,13 +142,13 @@ public interface ViaPlatform<T> {
     /**
      * Disconnects an UserConnection for a reason
      *
-     * @param connection    The UserConnection
-     * @param message The message to kick them with
+     * @param connection The UserConnection
+     * @param message    The message to kick them with
      * @return True if it was successful
      */
     default boolean disconnect(UserConnection connection, String message) {
         if (connection.isClientSide()) return false;
-        UUID uuid = connection.get(ProtocolInfo.class).getUuid();
+        UUID uuid = connection.getProtocolInfo().getUuid();
         if (uuid == null) return false;
         return kickPlayer(uuid, message);
     }
@@ -194,5 +209,13 @@ public interface ViaPlatform<T> {
      */
     boolean isOldClientsAllowed();
 
-    ViaConnectionManager getConnectionManager();
+    /**
+     * Returns an immutable collection of classes to be checked as unsupported software with their software name.
+     * If any of the classes exist at runtime, a warning about their potential instability will be given to the console.
+     *
+     * @return immutable collection of unsupported software to be checked
+     */
+    default Collection<UnsupportedSoftware> getUnsupportedSoftwareClasses() {
+        return Collections.emptyList();
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/platform/ViaPlatformLoader.java

@@ -0,0 +1,33 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.platform;
+
+public interface ViaPlatformLoader {
+
+    /**
+     * Initialise the loading for a platform, eg. registering listeners / providers / events etc.
+     */
+    void load();
+
+    void unload();
+}

api/src/main/java/com/viaversion/viaversion/api/platform/providers/Provider.java

@@ -0,0 +1,26 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package com.viaversion.viaversion.api.platform.providers;
+
+public interface Provider {
+}