Bump versions

Implement new chunk transformer

.gitignore

@@ -1,3 +1,116 @@
-target/
-.idea/
+### Java files ###
+*.class
+
+# Package Files
+#*.jar
+*.war
+*.ear
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+
+
+
+### Intellij ###
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm
+# Ignore project files
 *.iml
+
+# Ignore IDEA directory
+.idea/*
+
+# Include the project's code style settings file
+!.idea/codeStyleSettings.xml
+
+# Include the project's dictionary
+!.idea/dictionaries/
+!.idea/dictionaries/*
+
+# File-based project format:
+*.ipr
+*.iws
+
+### Plugin-specific files: ###
+# IntelliJ
+/out/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+
+
+
+### Eclipse ###
+*.pydevproject
+.metadata
+.gradle
+bin/
+tmp/
+*.tmp
+*.bak
+*.swp
+*~.nib
+local.properties
+.settings/
+.loadpath
+
+# Eclipse Core
+.project
+
+# External tool builders
+.externalToolBuilders/
+
+# Locally stored "Eclipse launch configurations"
+*.launch
+
+# CDT-specific
+.cproject
+
+# JDT-specific (Eclipse Java Development Tools)
+.classpath
+
+# PDT-specific
+.buildpath
+
+# sbteclipse plugin
+.target
+
+# TeXlipse plugin
+.texlipse
+
+
+
+### Maven ###
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+
+
+
+### NetBeans ###
+nbproject/private/
+build/
+nbbuild/
+dist/
+nbdist/
+nbactions.xml
+nb-configuration.xml
+.nb-gradle/
+
+
+
+### Git ###
+# Don't exclude the .gitignore itself
+!.gitignore

.travis.yml

@@ -0,0 +1,12 @@
+sudo: false
+
+language: java
+jdk: oraclejdk7
+
+cache:
+  directories:
+    - '$HOME/.m2/repository'
+
+script:
+  - mvn dependency:purge-local-repository -DactTransitively=false -DreResolve=false
+  - mvn clean install -B -U

ISSUE_TEMPLATE.md

@@ -0,0 +1,12 @@
+### What version of ViaVersion are you using? Type /ver viaversion
+
+### What version of Spigot are you using? Type /ver
+
+### What plugins are you using? Type /plugins
+
+### Are you using any additional software like BungeeCord? If so, what software and version? (Please list your plugins as well)
+
+### How does this error happen? login? Using an item? 
+
+### Is there an error in the console? Use pastebin.com. Is there a kick message?
+

LICENSE

@@ -0,0 +1,3 @@
+License:
+--------
+You may modify this work, all rights are still owned by myself excluding any files in the spacebase package as they belong to the respected contributors. Please credit the original author (myself) when forking etc. (or if it helped you understand the new protocol or netty!)

README.md

@@ -1,34 +1,64 @@
-# ViaVersion 0.3.1
-**Allows the connection of 1.8 clients to 1.9**
+# ViaVersion 0.6.4
+[![Build Status](https://travis-ci.org/MylesIsCool/ViaVersion.svg?branch=master)](https://travis-ci.org/MylesIsCool/ViaVersion)
+**Allows the connection of 1.9 clients to 1.8**
 
 This plugin modifies netty to allow connection of 1.9 clients to 1.8,
 
-**Don't use late bind nor ProtocolLib**
-
-**As of this point it doesn't have everything, I need to fix:**
-
-Attempt to make boats nicer when they don't work
-
-Remap spawn eggs
-
-Some EntityMetadata is incorrect, fix this.
-
+###*Don't use late bind*
 
 
 This took hours of work, so if you enjoy this consider looking into contacting me and supporting my projects.
 
+**Contributor Chat:** https://gitter.im/MylesIsCool/ViaVersion
 
-Credits:
+
+Sources:
 --------
 
 **wiki.vg** (Protocol info, though I did have to find a lot myself)
 
 **MCProtocolLib** (used for chunk reading & some of writing.)
 
+**OpenNBT** (used for slot rewriting)
+
+
+
+Contributors:
+--------
+
 **Myself** (harhar)
 
-**Matsv** (Movement Fix / Correcting my stupidity)
+**Matsv/StamBoom**
 
+**HugoDaBosss**
+
+**SanderGielisse**
+
+**Paulomart**
+
+**gigosaurus**
+
+**fillefilip8**
+
+**lenis0012**
+
+
+
+Releases / Dev Builds:
+--------
+You can find official releases here:
+
+https://www.spigotmc.org/resources/viaversion.19254/history
+
+
+----------
+
+You can find unofficial dev builds here:
+
+**fillefilip8's Build Server:** http://build.fillecraft.com:8080/job/ViaVersion
+
+**sgdc3's Build Server:** http://ci.xephi.fr/job/ViaVersion/
+**sgdc3's Maven:** http://ci.xephi.fr/plugin/repository/everything/
 
 License:
 --------
@@ -36,4 +66,5 @@ License:
 You may modify this work, all rights are still owned by myself excluding any files in the spacebase package as they belong to the respected contributors. Please credit the original author (myself) when forking etc. (or if it helped you understand the new protocol or netty!)
 
 
-Thanks!
+Thanks!
+

circle.yml

@@ -0,0 +1,11 @@
+machine:
+  java:
+    version: oraclejdk7
+general:
+  artifacts:
+    - "target/*.jar"
+test:
+  override:
+    - mvn clean install -B
+  post:
+    - cp ./target/*.jar $CIRCLE_ARTIFACTS

pom.xml

@@ -1,54 +1,181 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xmlns="http://maven.apache.org/POM/4.0.0"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
     <groupId>us.myles</groupId>
-    <artifactId>ViaVersion</artifactId>
-    <version>1.0-SNAPSHOT</version>
+    <artifactId>viaversion</artifactId>
+    <version>0.6.5-SNAPSHOT</version>
+    <packaging>jar</packaging>
+
+    <name>ViaVersion</name>
+    <description>Allow 1.8 clients to join 1.9 bukkit servers!</description>
+    <inceptionYear>2016</inceptionYear>
+    <url>https://www.spigotmc.org/resources/viaversion.19254/</url>
+
+    <prerequisites>
+        <maven>3.3.3</maven>
+    </prerequisites>
+
+    <properties>
+        <!-- Project Properties -->
+        <projectEncoding>UTF-8</projectEncoding>
+        <project.build.sourceEncoding>${projectEncoding}</project.build.sourceEncoding>
+        <project.build.outputEncoding>${projectEncoding}</project.build.outputEncoding>
+        <jdkVersion>1.7</jdkVersion>
+        <!-- <testJreVersion>1.7</testJreVersion> -->
+
+        <!-- Change Bukkit Version HERE! -->
+        <bukkitVersion>1.8.8-R0.1-SNAPSHOT</bukkitVersion>
+    </properties>
+
     <build>
+        <finalName>${project.name}-${project.version}</finalName>
+        <sourceDirectory>src/main/java</sourceDirectory>
+        <!-- <testSourceDirectory>src/test/java</testSourceDirectory> -->
+
+        <resources>
+            <resource>
+                <targetPath>.</targetPath>
+                <filtering>false</filtering>
+                <directory>.</directory>
+                <includes>
+                    <include>LICENSE</include>
+                </includes>
+            </resource>
+            <resource>
+                <targetPath>.</targetPath>
+                <filtering>true</filtering>
+                <directory>src/main/resources/</directory>
+                <includes>
+                    <include>*</include>
+                </includes>
+            </resource>
+        </resources>
+        <!--
+        <testResources>
+            <testResource>
+                <directory>src/test/resources</directory>
+            </testResource>
+        </testResources>
+        -->
+
         <plugins>
+            <!-- Maven Java Compiler -->
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.5.1</version>
                 <configuration>
-                    <source>1.7</source>
-                    <target>1.7</target>
+                    <source>${jdkVersion}</source>
+                    <target>${jdkVersion}</target>
+                    <!--
+                    <testSource>${testJreVersion}</testSource>
+                    <testTarget>${testJreVersion}</testTarget>
+                    -->
                 </configuration>
             </plugin>
+            <!-- Unit Test Plugin
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>2.19.1</version>
+                <configuration>
+                    <argLine>-Dfile.encoding=${projectEncoding} ${argLine}</argLine>
+                </configuration>
+            </plugin>
+			-->
+            <!-- Libs Shading and Relocation -->
+            <plugin>
+                <!--Relocate all lib we use in order to fix class loading errors if we use different versions
+                than already loaded libs (i.e. by Mojang -> gson)-->
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>2.4.3</version>
+                <configuration>
+                    <createDependencyReducedPom>false</createDependencyReducedPom>
+                    <minimizeJar>false</minimizeJar>
+                    <relocations>
+                        <relocation>
+                            <pattern>org.spacehq.opennbt</pattern>
+                            <shadedPattern>us.myles.viaversion.libs.opennbt</shadedPattern>
+                        </relocation>
+                    </relocations>
+                </configuration>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
+
+    <repositories>
+        <!-- SpigotMC Repo (Bukkit API) -->
+        <repository>
+            <id>spigot-repo</id>
+            <url>https://hub.spigotmc.org/nexus/content/repositories/snapshots</url>
+        </repository>
+
+        <!-- SpaceHQ Repo-->
+        <repository>
+            <id>spacehq-repo</id>
+            <url>https://repo.spacehq.org/content/repositories/releases/</url>
+        </repository>
+    </repositories>
+
     <dependencies>
+        <!-- Bukkit API, http://www.spigotmc.org/ or http://bukkit.org/ -->
         <dependency>
             <groupId>org.bukkit</groupId>
             <artifactId>bukkit</artifactId>
-            <version>1.8.8-R0.1-SNAPSHOT</version>
+            <version>${bukkitVersion}</version>
             <scope>provided</scope>
+            <optional>true</optional>
+            <exclusions>
+                <exclusion>
+                    <artifactId>junit</artifactId>
+                    <groupId>junit</groupId>
+                </exclusion>
+                <exclusion>
+                    <artifactId>gson</artifactId>
+                    <groupId>com.google.code.gson</groupId>
+                </exclusion>
+                <exclusion>
+                    <artifactId>persistence-api</artifactId>
+                    <groupId>javax.persistence</groupId>
+                </exclusion>
+            </exclusions>
         </dependency>
+
+        <!-- NBT Edit Library -->
+        <dependency>
+            <groupId>org.spacehq</groupId>
+            <artifactId>opennbt</artifactId>
+            <version>1.0</version>
+            <scope>compile</scope>
+            <optional>true</optional>
+        </dependency>
+
+        <!-- Netty (Network Library) -->
         <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-all</artifactId>
             <version>4.0.20.Final</version>
             <scope>provided</scope>
+            <optional>true</optional>
         </dependency>
+        <!-- Lombok -->
         <dependency>
-            <groupId>com.google.code.gson</groupId>
-            <artifactId>gson</artifactId>
-            <version>2.4</version>
-            <scope>provided</scope>
-        </dependency>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>18.0</version>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.16.6</version>
             <scope>provided</scope>
         </dependency>
     </dependencies>
-    <repositories>
-        <repository>
-            <id>spigot-repo</id>
-            <url>https://hub.spigotmc.org/nexus/content/repositories/snapshots/</url>
-        </repository>
-   </repositories>
 </project>

src/main/java/org/spacehq/mc/protocol/data/game/chunk/BlockStorage.java

@@ -1,7 +1,7 @@
 package org.spacehq.mc.protocol.data.game.chunk;
 
 import io.netty.buffer.ByteBuf;
-import us.myles.ViaVersion.PacketUtil;
+import us.myles.ViaVersion.util.PacketUtil;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -17,7 +17,7 @@ public class BlockStorage {
     public BlockStorage() {
         this.bitsPerEntry = 4;
 
-        this.states = new ArrayList<Integer>();
+        this.states = new ArrayList<>();
         this.states.add(0);
 
         this.storage = new FlexibleStorage(this.bitsPerEntry, 4096);
@@ -26,7 +26,7 @@ public class BlockStorage {
     public BlockStorage(ByteBuf in) throws IOException {
         this.bitsPerEntry = in.readUnsignedByte();
 
-        this.states = new ArrayList<Integer>();
+        this.states = new ArrayList<>();
         int stateCount = PacketUtil.readVarInt(in);
         for (int i = 0; i < stateCount; i++) {
             this.states.add(PacketUtil.readVarInt(in));
@@ -35,6 +35,10 @@ public class BlockStorage {
         this.storage = new FlexibleStorage(this.bitsPerEntry, PacketUtil.readLongs(PacketUtil.readVarInt(in), in));
     }
 
+    private static int index(int x, int y, int z) {
+        return y << 8 | z << 4 | x;
+    }
+
     public void write(ByteBuf out) throws IOException {
         out.writeByte(this.bitsPerEntry);
 
@@ -78,7 +82,7 @@ public class BlockStorage {
 
                 List<Integer> oldStates = this.states;
                 if (this.bitsPerEntry > 8) {
-                    oldStates = new ArrayList<Integer>(this.states);
+                    oldStates = new ArrayList<>(this.states);
                     this.states.clear();
                     this.bitsPerEntry = 13;
                 }
@@ -107,10 +111,6 @@ public class BlockStorage {
         return true;
     }
 
-    private static int index(int x, int y, int z) {
-        return y << 8 | z << 4 | x;
-    }
-
     @Override
     public boolean equals(Object o) {
         return this == o || (o instanceof BlockStorage && this.bitsPerEntry == ((BlockStorage) o).bitsPerEntry && this.states.equals(((BlockStorage) o).states) && this.storage.equals(((BlockStorage) o).storage));

src/main/java/org/spacehq/mc/protocol/data/game/chunk/Column.java

@@ -1,5 +1,10 @@
 package org.spacehq.mc.protocol.data.game.chunk;
 
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
 public class Column {
     private int x;
     private int z;
@@ -23,9 +28,9 @@ public class Column {
 
         this.skylight = false;
         boolean noSkylight = false;
-        for(int index = 0; index < chunks.length; index++) {
-            if(chunks[index] != null) {
-                if(chunks[index].getSkyLight() == null) {
+        for (Chunk chunk : chunks) {
+            if (chunk != null) {
+                if (chunk.getSkyLight() == null) {
                     noSkylight = true;
                 } else {
                     this.skylight = true;
@@ -43,26 +48,11 @@ public class Column {
         this.biomeData = biomeData;
     }
 
-    public int getX() {
-        return this.x;
-    }
-
-    public int getZ() {
-        return this.z;
-    }
-
-    public Chunk[] getChunks() {
-        return this.chunks;
-    }
 
     public boolean hasBiomeData() {
         return this.biomeData != null;
     }
 
-    public byte[] getBiomeData() {
-        return this.biomeData;
-    }
-
     public boolean hasSkylight() {
         return this.skylight;
     }

src/main/java/org/spacehq/mc/protocol/util/NetUtil.java

@@ -18,19 +18,19 @@ public class NetUtil {
     public static int writeNewColumn(ByteBuf out, Column column, boolean fullChunk, boolean hasSkylight) throws IOException {
         int mask = 0;
         Chunk chunks[] = column.getChunks();
-        for(int index = 0; index < chunks.length; index++) {
+        for (int index = 0; index < chunks.length; index++) {
             Chunk chunk = chunks[index];
-            if(chunk != null && (!fullChunk || !chunk.isEmpty())) {
+            if (chunk != null && (!fullChunk || !chunk.isEmpty())) {
                 mask |= 1 << index;
                 chunk.getBlocks().write(out);
                 chunk.getBlockLight().write(out);
-                if(hasSkylight || column.hasSkylight()) {
+                if (hasSkylight || column.hasSkylight()) {
                     chunk.getSkyLight().write(out); // TODO: Make a PR to original lib to correct this
                 }
             }
         }
 
-        if(fullChunk) {
+        if (fullChunk && column.getBiomeData() != null) {
             out.writeBytes(column.getBiomeData());
         }
 
@@ -39,7 +39,7 @@ public class NetUtil {
 
     public static Column readOldChunkData(int x, int z, boolean isFullChunk, int bitmask, byte[] input, boolean checkForSky, boolean hasSkyLight) {
         int pos = 0;
-        int expected = 0;
+        int expected = isFullChunk ? 256 : 0;
         boolean sky = false;
         ShortBuffer buf = ByteBuffer.wrap(input).order(ByteOrder.LITTLE_ENDIAN).asShortBuffer();
         // 0 = Calculate expected length and determine if the packet has skylight.
@@ -47,45 +47,47 @@ public class NetUtil {
         // 2 = Get block light.
         // 3 = Get sky light.
         Chunk[] chunks = new Chunk[16];
-
-        for(int pass = 0; pass < 4; pass++) {
-            for(int ind = 0; ind < 16; ind++) {
-                if((bitmask & 1 << ind) != 0) {
-                    if(pass == 0) {
+        int chunkCount = 0;
+        for (int pass = 0; pass < 4; pass++) {
+            if(pass == 1){
+                if(chunkCount == 0) return null;
+            }
+            for (int ind = 0; ind < 16; ind++) {
+                if ((bitmask & 1 << ind) != 0) {
+                    if (pass == 0) {
+                        chunkCount++;
                         // Block length + Blocklight length
                         expected += (4096 * 2) + 2048;
                     }
 
-                    if(pass == 1) {
+                    if (pass == 1) {
                         chunks[ind] = new Chunk(sky || hasSkyLight);
-
                         buf.position(pos / 2);
-                        short[] tempData = new short[4096];
-                        buf.get(tempData, 0, tempData.length);
+                        int buffPos = buf.position();
                         // convert short array to new one
-                        int index = 0;
-                        for(short ss:tempData){
+
+                        for (int index = 0; index < 4096; index++) {
+                            short ss = buf.get(buffPos + index);
                             // s is 16 bits, 12 bits id and 4 bits data
                             int data = ss & 0xF;
                             int id = (ss >> 4) << 4 | data;
 
-                            int newCombined = id ; // test
+                            int newCombined = id; // test
 
                             chunks[ind].getBlocks().set(index, newCombined);
-                            index++;
                         }
-                        pos += tempData.length * 2;
+                        pos += 4096 * 2;
 
                     }
 
-                    if(pass == 2) {
+                    if (pass == 2) {
                         NibbleArray3d blocklight = chunks[ind].getBlockLight();
                         System.arraycopy(input, pos, blocklight.getData(), 0, blocklight.getData().length);
                         pos += blocklight.getData().length;
                     }
 
-                    if(pass == 3) {
-                        if(chunks[ind].getSkyLight() != null) {
+                    if (pass == 3) {
+                        if (sky) {
                             NibbleArray3d skylight = chunks[ind].getSkyLight();
                             System.arraycopy(input, pos, skylight.getData(), 0, skylight.getData().length);
                             pos += skylight.getData().length;
@@ -94,16 +96,17 @@ public class NetUtil {
                 }
             }
 
-            if(pass == 0) {
+            if (pass == 0) {
                 // If we have more data than blocks and blocklight combined, there must be skylight data as well.
-                if(input.length > expected) {
+                if (input.length > expected) {
                     sky = checkForSky;
                 }
             }
         }
 
         byte biomeData[] = null;
-        if(isFullChunk) {
+        if (isFullChunk && (pos + 256 <= input.length)) {
+
             biomeData = new byte[256];
             System.arraycopy(input, pos, biomeData, 0, biomeData.length);
         }

src/main/java/us/myles/ViaVersion/CancelException.java

@@ -1,4 +1,4 @@
 package us.myles.ViaVersion;
 
-public class CancelException extends Exception{
+public class CancelException extends Exception {
 }

src/main/java/us/myles/ViaVersion/ConnectionInfo.java

@@ -1,59 +1,73 @@
 package us.myles.ViaVersion;
 
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandler;
+import io.netty.channel.socket.SocketChannel;
+import lombok.Getter;
+import lombok.Setter;
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
+import us.myles.ViaVersion.chunks.ChunkManager;
 import us.myles.ViaVersion.packets.State;
 
-import java.util.UUID;
-
+@Getter
+@Setter
 public class ConnectionInfo {
-    private int protocol = 0;
-    private State state = State.HANDSHAKE;
-    private int compression = 0;
+    private static final long IDLE_PACKET_DELAY = 50L; // Update every 50ms (20tps)
+    private static final long IDLE_PACKET_LIMIT = 20; // Max 20 ticks behind
+
+    private final SocketChannel channel;
+    private final ChunkManager chunkManager;
     private Object lastPacket;
     private java.util.UUID UUID;
+    private State state = State.HANDSHAKE;
+    private String openWindow;
+    private int protocol = 0;
+    private int compression = 0;
+    private int entityID;
+    private boolean active = true;
+    private String username;
+    private long nextIdlePacket = 0L;
 
-    public int getProtocol() {
-        return protocol;
-    }
-
-    public void setProtocol(int protocol) {
-        this.protocol = protocol;
-    }
-
-    public State getState() {
-        return state;
-    }
-
-    public void setState(State state) {
-        this.state = state;
-    }
-
-    public void setCompression(int compression) {
-        this.compression = compression;
-    }
-
-    public int getCompression() {
-        return compression;
-    }
-
-    public void setLastPacket(Object lastPacket) {
-        this.lastPacket = lastPacket;
-    }
-
-    public Object getLastPacket() {
-        return lastPacket;
-    }
-
-    public void setUUID(UUID UUID) {
-        this.UUID = UUID;
-    }
-
-    public java.util.UUID getUUID() {
-        return UUID;
+    public ConnectionInfo(SocketChannel socketChannel) {
+        this.channel = socketChannel;
+        this.chunkManager = new ChunkManager(this);
     }
 
     public Player getPlayer() {
         return UUID == null ? null : Bukkit.getPlayer(UUID);
     }
+
+    public void setActive(boolean active) {
+        this.active = active;
+        this.nextIdlePacket = System.currentTimeMillis() + IDLE_PACKET_DELAY; // Update every 50 ticks
+    }
+
+    public void sendRawPacket(final ByteBuf packet, boolean currentThread) {
+        final ChannelHandler handler = channel.pipeline().get("encoder");
+        if (currentThread) {
+            channel.pipeline().context(handler).writeAndFlush(packet);
+        } else {
+            channel.eventLoop().submit(new Runnable() {
+                @Override
+                public void run() {
+                    channel.pipeline().context(handler).writeAndFlush(packet);
+                }
+            });
+        }
+    }
+
+    public void sendRawPacket(final ByteBuf packet) {
+        sendRawPacket(packet, false);
+    }
+
+    public void closeWindow() {
+        this.openWindow = null;
+    }
+
+    public void incrementIdlePacket() {
+        // Notify of next update
+        // Allow a maximum lag spike of 1 second (20 ticks/updates)
+        this.nextIdlePacket = Math.max(nextIdlePacket + IDLE_PACKET_DELAY, System.currentTimeMillis() - IDLE_PACKET_DELAY * IDLE_PACKET_LIMIT);
+    }
 }

src/main/java/us/myles/ViaVersion/Core.java

@@ -1,94 +0,0 @@
-package us.myles.ViaVersion;
-
-import io.netty.channel.ChannelFuture;
-import io.netty.channel.ChannelHandler;
-import io.netty.channel.ChannelInitializer;
-import io.netty.channel.ChannelPipeline;
-import io.netty.channel.socket.SocketChannel;
-import org.bukkit.Bukkit;
-import org.bukkit.entity.Entity;
-import org.bukkit.entity.Player;
-import org.bukkit.inventory.ItemStack;
-import org.bukkit.plugin.java.JavaPlugin;
-import us.myles.ViaVersion.handlers.ViaVersionInitializer;
-
-import java.util.List;
-import java.util.UUID;
-import java.util.concurrent.Callable;
-import java.util.concurrent.TimeUnit;
-
-public class Core extends JavaPlugin {
-    @Override
-    public void onEnable() {
-        System.out.println("ViaVersion enabled, injecting. (Allows 1.8 to be accessed via 1.9)");
-        try {
-            injectPacketHandler();
-        } catch (Exception e) {
-            if(Bukkit.getPluginManager().getPlugin("ProtocolLib") != null){
-                System.out.println("This plugin is not compatible with protocol lib.");
-            }
-            System.out.println("Unable to inject handlers, are you on 1.8? ");
-            e.printStackTrace();
-        }
-    }
-
-    public void injectPacketHandler() throws Exception {
-        Class<?> serverClazz = ReflectionUtil.nms("MinecraftServer");
-        Object server = ReflectionUtil.invokeStatic(serverClazz, "getServer");
-        Object connection = serverClazz.getDeclaredMethod("getServerConnection").invoke(server);
-
-        List<ChannelFuture> futures = ReflectionUtil.get(connection, "g", List.class);
-        if (futures.size() == 0) {
-            throw new Exception("Could not find server to inject (late bind?)");
-        }
-
-        for (ChannelFuture future : futures) {
-            ChannelPipeline pipeline = future.channel().pipeline();
-            ChannelHandler bootstrapAcceptor = pipeline.first();
-            ChannelInitializer<SocketChannel> oldInit = ReflectionUtil.get(bootstrapAcceptor, "childHandler", ChannelInitializer.class);
-            ChannelInitializer newInit = new ViaVersionInitializer(oldInit);
-            ReflectionUtil.set(bootstrapAcceptor, "childHandler", newInit);
-        }
-    }
-
-
-    public static Entity getEntity(final UUID player, final int id) {
-        try {
-            return Bukkit.getScheduler().callSyncMethod(getPlugin(Core.class), new Callable<Entity>() {
-                @Override
-                public Entity call() throws Exception {
-                    Player p = Bukkit.getPlayer(player);
-                    if (p == null) return null;
-                    for (Entity e : p.getWorld().getEntities()) {
-                        if (e.getEntityId() == id) {
-                            return e;
-                        }
-                    }
-                    return null;
-                }
-            }).get(10, TimeUnit.SECONDS);
-        } catch (Exception e) {
-            System.out.println("Error fetching entity ");
-            e.printStackTrace();
-            return null;
-        }
-    }
-
-    public static ItemStack getHandItem(final ConnectionInfo info) {
-        try {
-            return Bukkit.getScheduler().callSyncMethod(getPlugin(Core.class), new Callable<ItemStack>() {
-                @Override
-                public ItemStack call() throws Exception {
-                    if (info.getPlayer() != null) {
-                        return info.getPlayer().getItemInHand();
-                    }
-                    return null;
-                }
-            }).get(10, TimeUnit.SECONDS);
-        } catch (Exception e) {
-            System.out.println("Error fetching hand item ");
-            e.printStackTrace();
-            return null;
-        }
-    }
-}

src/main/java/us/myles/ViaVersion/ReflectionUtil.java

@@ -1,41 +0,0 @@
-package us.myles.ViaVersion;
-
-import org.bukkit.Bukkit;
-
-import java.lang.reflect.Field;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-
-public class ReflectionUtil {
-    private static String BASE = Bukkit.getServer().getClass().getPackage().getName();
-    private static String NMS = BASE.replace("org.bukkit.craftbukkit", "net.minecraft.server");
-
-    public static Class<?> nms(String className) throws ClassNotFoundException {
-        return Class.forName(NMS + "." + className);
-    }
-    public static Class<?> obc(String className) throws ClassNotFoundException {
-        return Class.forName(BASE + "." + className);
-    }
-
-    public static Object invokeStatic(Class<?> clazz, String method) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
-        Method m = clazz.getDeclaredMethod(method);
-        return m.invoke(null);
-    }
-
-    public static Object invoke(Object o, String method) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
-        Method m = o.getClass().getDeclaredMethod(method);
-        return m.invoke(o);
-    }
-
-    public static <T> T get(Object o, String f, Class<T> t) throws NoSuchFieldException, IllegalAccessException {
-        Field field = o.getClass().getDeclaredField(f);
-        field.setAccessible(true);
-        return (T) field.get(o);
-    }
-
-    public static void set(Object o, String f, Object value) throws NoSuchFieldException, IllegalAccessException {
-        Field field = o.getClass().getDeclaredField(f);
-        field.setAccessible(true);
-        field.set(o, value);
-    }
-}

src/main/java/us/myles/ViaVersion/ViaIdleThread.java

@@ -0,0 +1,42 @@
+package us.myles.ViaVersion;
+
+import org.bukkit.scheduler.BukkitRunnable;
+import us.myles.ViaVersion.api.ViaVersion;
+import us.myles.ViaVersion.util.ReflectionUtil;
+
+import java.util.Map;
+import java.util.UUID;
+
+public class ViaIdleThread extends BukkitRunnable {
+    private final Map<UUID, ConnectionInfo> portedPlayers;
+    private final Class<?> idlePacketClass;
+
+    public ViaIdleThread(Map<UUID, ConnectionInfo> portedPlayers) {
+        this.portedPlayers = portedPlayers;
+        try {
+            this.idlePacketClass = ReflectionUtil.nms("PacketPlayInFlying");
+        } catch(ClassNotFoundException e) {
+            throw new RuntimeException("Couldn't find player idle packet, help!", e);
+        }
+    }
+
+    @Override
+    public void run() {
+        for(ConnectionInfo info : portedPlayers.values()) {
+            long nextIdleUpdate = info.getNextIdlePacket();
+            if(nextIdleUpdate <= System.currentTimeMillis()) {
+                try {
+                    Object packet = idlePacketClass.newInstance();
+                    info.getChannel().pipeline().fireChannelRead(packet);
+                } catch(InstantiationException | IllegalAccessException e) {
+                    System.out.println("Failed to create idle packet.");
+                    if(ViaVersion.getInstance().isDebug()) {
+                        e.printStackTrace();
+                    }
+                } finally {
+                    info.incrementIdlePacket();
+                }
+            }
+        }
+    }
+}

src/main/java/us/myles/ViaVersion/ViaVersionPlugin.java

@@ -0,0 +1,298 @@
+package us.myles.ViaVersion;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelHandler;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.socket.SocketChannel;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerQuitEvent;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.plugin.java.JavaPlugin;
+import us.myles.ViaVersion.api.ViaVersion;
+import us.myles.ViaVersion.api.ViaVersionAPI;
+import us.myles.ViaVersion.api.boss.BossBar;
+import us.myles.ViaVersion.api.boss.BossColor;
+import us.myles.ViaVersion.api.boss.BossStyle;
+import us.myles.ViaVersion.armor.ArmorListener;
+import us.myles.ViaVersion.boss.ViaBossBar;
+import us.myles.ViaVersion.commands.ViaVersionCommand;
+import us.myles.ViaVersion.handlers.ViaVersionInitializer;
+import us.myles.ViaVersion.listeners.CommandBlockListener;
+import us.myles.ViaVersion.update.UpdateListener;
+import us.myles.ViaVersion.update.UpdateUtil;
+import us.myles.ViaVersion.util.Configuration;
+import us.myles.ViaVersion.util.ListWrapper;
+import us.myles.ViaVersion.util.ReflectionUtil;
+
+import java.io.File;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+
+public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
+
+    private final Map<UUID, ConnectionInfo> portedPlayers = new ConcurrentHashMap<>();
+    private boolean debug = false;
+
+    public static ItemStack getHandItem(final ConnectionInfo info) {
+        try {
+            return Bukkit.getScheduler().callSyncMethod(Bukkit.getPluginManager().getPlugin("ViaVersion"), new Callable<ItemStack>() {
+                @Override
+                public ItemStack call() throws Exception {
+                    if (info.getPlayer() != null) {
+                        return info.getPlayer().getItemInHand();
+                    }
+                    return null;
+                }
+            }).get(10, TimeUnit.SECONDS);
+        } catch (Exception e) {
+            System.out.println("Error fetching hand item: " + e.getClass().getName());
+            if (ViaVersion.getInstance().isDebug())
+                e.printStackTrace();
+            return null;
+        }
+    }
+
+    @Override
+    public void onEnable() {
+        ViaVersion.setInstance(this);
+        generateConfig();
+        if (System.getProperty("ViaVersion") != null) {
+            getLogger().severe("ViaVersion is already loaded, we don't support reloads. Please reboot if you wish to update.");
+            getLogger().severe("Some features may not work.");
+            return;
+        }
+
+        getLogger().info("ViaVersion " + getDescription().getVersion() + " is now enabled, injecting. (Allows 1.8 to be accessed via 1.9)");
+        injectPacketHandler();
+        if (getConfig().getBoolean("simulate-pt", true))
+            new ViaIdleThread(portedPlayers).runTaskTimerAsynchronously(this, 1L, 1L); // Updates player's idle status
+
+        if (getConfig().getBoolean("checkforupdates"))
+            UpdateUtil.sendUpdateMessage(this);
+
+        Bukkit.getPluginManager().registerEvents(new Listener() {
+            @EventHandler
+            public void onPlayerQuit(PlayerQuitEvent e) {
+                removePortedClient(e.getPlayer().getUniqueId());
+            }
+        }, this);
+
+        Bukkit.getPluginManager().registerEvents(new ArmorListener(this), this);
+        Bukkit.getPluginManager().registerEvents(new CommandBlockListener(this), this);
+        Bukkit.getPluginManager().registerEvents(new UpdateListener(this), this);
+
+        getCommand("viaversion").setExecutor(new ViaVersionCommand(this));
+    }
+
+    public void generateConfig() {
+        File file = new File(getDataFolder(), "config.yml");
+        if (file.exists()) {
+            // Update config options
+            Configuration oldConfig = new Configuration(file);
+            oldConfig.reload(false); // Load current options from config
+            file.delete(); // Delete old config
+            saveDefaultConfig(); // Generate new config
+            Configuration newConfig = new Configuration(file);
+            newConfig.reload(true); // Load default options
+            for (String key : oldConfig.getKeys(false)) {
+                // Set option in new config if exists
+                if (newConfig.contains(key)) {
+                    newConfig.set(key, oldConfig.get(key));
+                }
+            }
+            newConfig.save();
+        } else {
+            saveDefaultConfig();
+        }
+    }
+
+    public void injectPacketHandler() {
+        try {
+            Class<?> serverClazz = ReflectionUtil.nms("MinecraftServer");
+            Object server = ReflectionUtil.invokeStatic(serverClazz, "getServer");
+            Object connection = null;
+            for (Method m : serverClazz.getDeclaredMethods()) {
+                if (m.getReturnType() != null) {
+                    if (m.getReturnType().getSimpleName().equals("ServerConnection")) {
+                        if (m.getParameterTypes().length == 0) {
+                            connection = m.invoke(server);
+                        }
+                    }
+                }
+            }
+            if (connection == null) {
+                getLogger().warning("We failed to find the ServerConnection? :( What server are you running?");
+                return;
+            }
+            if (connection != null) {
+                for (Field field : connection.getClass().getDeclaredFields()) {
+                    field.setAccessible(true);
+                    final Object value = field.get(connection);
+                    if (value instanceof List) {
+                        // Inject the list
+                        List wrapper = new ListWrapper((List) value) {
+                            @Override
+                            public synchronized void handleAdd(Object o) {
+                                synchronized (this) {
+                                    if (o instanceof ChannelFuture) {
+                                        inject((ChannelFuture) o);
+                                    }
+                                }
+                            }
+                        };
+                        field.set(connection, wrapper);
+                        // Iterate through current list
+                        synchronized (wrapper) {
+                            for (Object o : (List) value) {
+                                if (o instanceof ChannelFuture) {
+                                    inject((ChannelFuture) o);
+                                } else {
+                                    break; // not the right list.
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            System.setProperty("ViaVersion", getDescription().getVersion());
+        } catch (Exception e) {
+            getLogger().severe("Unable to inject handlers, are you on 1.8? ");
+            e.printStackTrace();
+        }
+    }
+
+    private void inject(ChannelFuture future) {
+        try {
+            ChannelHandler bootstrapAcceptor = future.channel().pipeline().first();
+            try {
+                ChannelInitializer<SocketChannel> oldInit = ReflectionUtil.get(bootstrapAcceptor, "childHandler", ChannelInitializer.class);
+                ChannelInitializer newInit = new ViaVersionInitializer(oldInit);
+
+                ReflectionUtil.set(bootstrapAcceptor, "childHandler", newInit);
+            } catch (NoSuchFieldException e) {
+                // field not found
+                throw new Exception("Unable to find childHandler, blame " + bootstrapAcceptor.getClass().getName());
+            }
+        } catch (Exception e) {
+            getLogger().severe("Have you got late-bind enabled with something else? (ProtocolLib?)");
+            e.printStackTrace();
+        }
+    }
+
+    @Override
+    public boolean isPorted(Player player) {
+        return isPorted(player.getUniqueId());
+    }
+
+    @Override
+    public boolean isPorted(UUID playerUUID) {
+        return portedPlayers.containsKey(playerUUID);
+    }
+
+    @Override
+    public String getVersion() {
+        return getDescription().getVersion();
+    }
+
+    public void sendRawPacket(Player player, ByteBuf packet) throws IllegalArgumentException {
+        sendRawPacket(player.getUniqueId(), packet);
+    }
+
+    @Override
+    public void sendRawPacket(UUID uuid, ByteBuf packet) throws IllegalArgumentException {
+        if (!isPorted(uuid)) throw new IllegalArgumentException("This player is not on 1.9");
+        ConnectionInfo ci = portedPlayers.get(uuid);
+        ci.sendRawPacket(packet);
+    }
+
+    @Override
+    public BossBar createBossBar(String title, BossColor color, BossStyle style) {
+        return new ViaBossBar(title, 1F, color, style);
+    }
+
+    @Override
+    public BossBar createBossBar(String title, float health, BossColor color, BossStyle style) {
+        return new ViaBossBar(title, health, color, style);
+    }
+
+    @Override
+    public boolean isDebug() {
+        return this.debug;
+    }
+
+    public void setDebug(boolean value) {
+        this.debug = value;
+    }
+
+    public boolean isPreventCollision() {
+        return getConfig().getBoolean("prevent-collision", true);
+    }
+
+    public boolean isSuppressMetadataErrors() {
+        return getConfig().getBoolean("suppress-metadata-errors", false);
+    }
+
+    public boolean isShieldBlocking() {
+        return getConfig().getBoolean("shield-blocking", true);
+    }
+
+    public boolean isHologramPatch() {
+        return getConfig().getBoolean("hologram-patch", false);
+    }
+
+    public boolean isBossbarPatch() {
+        return getConfig().getBoolean("bossbar-patch", true);
+    }
+
+    public boolean isBossbarAntiflicker() {
+        return getConfig().getBoolean("bossbar-anti-flicker", false);
+    }
+
+    public double getHologramYOffset() {
+        return getConfig().getDouble("hologram-y", -1D);
+    }
+
+    public boolean isAutoTeam() {
+        // Collision has to be enabled first
+        if (!isPreventCollision()) return false;
+        return getConfig().getBoolean("auto-team", true);
+    }
+
+    public void addPortedClient(ConnectionInfo info) {
+        portedPlayers.put(info.getUUID(), info);
+    }
+
+    public void removePortedClient(UUID clientID) {
+        portedPlayers.remove(clientID);
+    }
+
+    public void run(final Runnable runnable, boolean wait) {
+        try {
+            Future f = Bukkit.getScheduler().callSyncMethod(Bukkit.getPluginManager().getPlugin("ViaVersion"), new Callable<Boolean>() {
+                @Override
+                public Boolean call() throws Exception {
+                    runnable.run();
+                    return true;
+                }
+            });
+            if (wait) {
+                f.get(10, TimeUnit.SECONDS);
+            }
+        } catch (Exception e) {
+            System.out.println("Failed to run task: " + e.getClass().getName());
+            if (ViaVersion.getInstance().isDebug())
+                e.printStackTrace();
+        }
+    }
+}

src/main/java/us/myles/ViaVersion/api/ViaVersion.java

@@ -0,0 +1,11 @@
+package us.myles.ViaVersion.api;
+
+import lombok.Getter;
+import lombok.Setter;
+
+public class ViaVersion {
+
+    @Getter
+    @Setter
+    private static ViaVersionAPI instance;
+}

src/main/java/us/myles/ViaVersion/api/ViaVersionAPI.java

@@ -0,0 +1,80 @@
+package us.myles.ViaVersion.api;
+
+import io.netty.buffer.ByteBuf;
+import org.bukkit.entity.Player;
+import us.myles.ViaVersion.api.boss.BossBar;
+import us.myles.ViaVersion.api.boss.BossColor;
+import us.myles.ViaVersion.api.boss.BossStyle;
+
+import java.util.UUID;
+
+public interface ViaVersionAPI {
+    /**
+     * Is player using 1.9?
+     *
+     * @param player
+     * @return True if the client is on 1.9
+     */
+    boolean isPorted(Player player);
+
+    /**
+     * Is player using 1.9?
+     *
+     * @param playerUUID
+     * @return True if the client is on 1.9
+     */
+    boolean isPorted(UUID playerUUID);
+
+    /**
+     * Get the version of the plugin
+     *
+     * @return Plugin version
+     */
+    String getVersion();
+
+    /**
+     * Send a raw packet to the player (Use new IDs)
+     *
+     * @param player The player to send packet
+     * @param packet The packet, you need a VarInt ID then the packet contents.
+     * @throws IllegalArgumentException If not on 1.9 throws IllegalArg
+     */
+    void sendRawPacket(Player player, ByteBuf packet) throws IllegalArgumentException;
+
+    /**
+     * Send a raw packet to the player (Use new IDs)
+     *
+     * @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 not on 1.9 throws IllegalArg
+     */
+    void sendRawPacket(UUID uuid, ByteBuf packet) throws IllegalArgumentException;
+
+    /**
+     * Create a new bossbar instance
+     *
+     * @param title The title
+     * @param color The color
+     * @param style The style
+     * @return Bossbar instance
+     */
+    BossBar createBossBar(String title, BossColor color, BossStyle style);
+
+    /**
+     * Create a new bossbar instance
+     *
+     * @param title  The title
+     * @param health Number between 0 and 1
+     * @param color  The color
+     * @param style  The style
+     * @return Bossbar instance
+     */
+    BossBar createBossBar(String title, float health, BossColor color, BossStyle style);
+
+    /**
+     * Obtain if global debug is enabled
+     *
+     * @return true if debug is enabled
+     */
+    boolean isDebug();
+}

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

@@ -0,0 +1,122 @@
+package us.myles.ViaVersion.api.boss;
+
+import org.bukkit.entity.Player;
+
+import java.util.Set;
+import java.util.UUID;
+
+public interface BossBar {
+    /**
+     * Change the title
+     *
+     * @param title Title can be in either JSON or just text
+     */
+    void setTitle(String title);
+
+    /**
+     * Get the current title
+     *
+     * @return the title
+     */
+    String getTitle();
+
+    /**
+     * Change the health
+     *
+     * @param health this float has to be between 0F - 1F
+     */
+    void setHealth(float health);
+
+    /**
+     * Get the health
+     *
+     * @return float between 0F - 1F
+     */
+    float getHealth();
+
+    /**
+     * Yay colors!
+     *
+     * @param color Whatever color you want!
+     */
+    void setColor(BossColor color);
+
+    /**
+     * Get the bossbar color
+     *
+     * @return
+     */
+    BossColor getColor();
+
+    /**
+     * Change the bosbar style
+     *
+     * @param style BossStyle
+     */
+    void setStyle(BossStyle style);
+
+    /**
+     * Get the bosbar style
+     *
+     * @return BossStyle
+     */
+    BossStyle getStyle();
+
+    /**
+     * Show the bossbar to a player.
+     *
+     * @param player
+     */
+    void addPlayer(Player player);
+
+    /**
+     * Remove the bossbar from a player
+     *
+     * @param player
+     */
+    void removePlayer(Player player);
+
+    /**
+     * Add flags
+     *
+     * @param flag
+     */
+    void addFlag(BossFlag flag);
+
+    /**
+     * Remove flags.
+     *
+     * @param flag
+     */
+    void removeFlag(BossFlag flag);
+
+    /**
+     * @param flag
+     * @return
+     */
+    boolean hasFlag(BossFlag flag);
+
+    /**
+     * Get players
+     *
+     * @return UUIDS from players (sorry I lied)
+     */
+    Set<UUID> getPlayers();
+
+    /**
+     * Show the bossbar to everyone (In the getPlayer set)
+     */
+    void show();
+
+    /**
+     * Hide the bossbar from everyone (In the getPlayer set)
+     */
+    void hide();
+
+    /**
+     * Is it visible?
+     *
+     * @return visibility changable with show() and hide()
+     */
+    boolean isVisible();
+}

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

@@ -0,0 +1,18 @@
+package us.myles.ViaVersion.api.boss;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+@Getter
+public enum BossColor {
+    PINK(0),
+    BLUE(1),
+    RED(2),
+    GREEN(3),
+    YELLOW(4),
+    PURPLE(5),
+    WHITE(6);
+
+    private final int id;
+}

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

@@ -0,0 +1,13 @@
+package us.myles.ViaVersion.api.boss;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+@Getter
+public enum BossFlag {
+    DARKEN_SKY(1),
+    PLAY_BOSS_MUSIC(2);
+
+    private final int id;
+}

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

@@ -0,0 +1,16 @@
+package us.myles.ViaVersion.api.boss;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+@Getter
+public enum BossStyle {
+    SOLID(0),
+    SEGMENTED_6(1),
+    SEGMENTED_10(2),
+    SEGMENTED_12(3),
+    SEGMENTED_20(4);
+
+    private final int id;
+}

src/main/java/us/myles/ViaVersion/armor/ArmorListener.java

@@ -0,0 +1,102 @@
+package us.myles.ViaVersion.armor;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import lombok.RequiredArgsConstructor;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.HumanEntity;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.block.Action;
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.bukkit.event.player.PlayerInteractEvent;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.inventory.CraftingInventory;
+import us.myles.ViaVersion.ViaVersionPlugin;
+import us.myles.ViaVersion.api.ViaVersion;
+import us.myles.ViaVersion.packets.PacketType;
+
+import java.util.UUID;
+
+import static us.myles.ViaVersion.util.PacketUtil.*;
+
+@RequiredArgsConstructor
+public class ArmorListener implements Listener {
+
+    private static final UUID ARMOR_ATTRIBUTE = UUID.fromString("2AD3F246-FEE1-4E67-B886-69FD380BB150");
+    private final ViaVersionPlugin plugin;
+
+    public static void sendArmorUpdate(Player player) {
+        int armor = ArmorType.calculateArmorPoints(player.getInventory().getArmorContents());
+
+        ByteBuf buf = Unpooled.buffer();
+        writeVarInt(PacketType.PLAY_ENTITY_PROPERTIES.getNewPacketID(), buf);
+        writeVarInt(player.getEntityId(), buf);
+        buf.writeInt(1); // only 1 property
+        writeString("generic.armor", buf);
+        buf.writeDouble(0); //default 0 armor
+        writeVarInt(1, buf); // 1 modifier
+        writeUUID(ARMOR_ATTRIBUTE, buf); // armor modifier uuid
+        buf.writeDouble((double) armor); // the modifier value
+        buf.writeByte(0); // the modifier operation, 0 is add number
+
+        ViaVersion.getInstance().sendRawPacket(player, buf);
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onInventoryClick(InventoryClickEvent e) {
+        HumanEntity human = e.getWhoClicked();
+        if (human instanceof Player && e.getInventory() instanceof CraftingInventory) {
+            final Player player = (Player) human;
+            if (ViaVersion.getInstance().isPorted(player)) {
+                if (e.getCurrentItem() != null) {
+                    if (ArmorType.isArmor(e.getCurrentItem().getType())) {
+                        sendDelayedArmorUpdate(player);
+                        return;
+                    }
+                }
+                if (e.getRawSlot() >= 5 && e.getRawSlot() <= 8) {
+                    sendDelayedArmorUpdate(player);
+                }
+            }
+        }
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onInteract(PlayerInteractEvent e) {
+        if (e.getItem() != null) {
+            if (e.getAction() == Action.RIGHT_CLICK_AIR || e.getAction() == Action.RIGHT_CLICK_BLOCK) {
+                if (ArmorType.isArmor(e.getMaterial())) {
+                    final Player player = e.getPlayer();
+                    // Due to odd bugs it's 3 ticks later
+                    Bukkit.getScheduler().scheduleSyncDelayedTask(plugin, new Runnable() {
+                        @Override
+                        public void run() {
+                            if (ViaVersion.getInstance().isPorted(player)) {
+                                sendArmorUpdate(player);
+                            }
+                        }
+                    }, 3L);
+                }
+            }
+        }
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onJoin(PlayerJoinEvent e) {
+        sendDelayedArmorUpdate(e.getPlayer());
+    }
+
+    public void sendDelayedArmorUpdate(final Player player) {
+        Bukkit.getScheduler().scheduleSyncDelayedTask(plugin, new Runnable() {
+            @Override
+            public void run() {
+                if (ViaVersion.getInstance().isPorted(player)) {
+                    sendArmorUpdate(player);
+                }
+            }
+        });
+    }
+}

src/main/java/us/myles/ViaVersion/armor/ArmorType.java

@@ -0,0 +1,81 @@
+package us.myles.ViaVersion.armor;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import org.bukkit.Material;
+import org.bukkit.inventory.ItemStack;
+
+@RequiredArgsConstructor
+@Getter
+public enum ArmorType {
+
+    LEATHER_HELMET(1, 298, Material.LEATHER_HELMET),
+    LEATHER_CHESTPLATE(3, 299, Material.LEATHER_CHESTPLATE),
+    LEATHER_LEGGINGS(2, 300, Material.LEATHER_LEGGINGS),
+    LEATHER_BOOTS(1, 301, Material.LEATHER_BOOTS),
+    CHAINMAIL_HELMET(2, 302, Material.CHAINMAIL_HELMET),
+    CHAINMAIL_CHESTPLATE(5, 303, Material.CHAINMAIL_CHESTPLATE),
+    CHAINMAIL_LEGGINGS(4, 304, Material.CHAINMAIL_LEGGINGS),
+    CHAINMAIL_BOOTS(1, 305, Material.CHAINMAIL_BOOTS),
+    IRON_HELMET(2, 306, Material.IRON_HELMET),
+    IRON_CHESTPLATE(6, 307, Material.IRON_CHESTPLATE),
+    IRON_LEGGINGS(5, 308, Material.IRON_LEGGINGS),
+    IRON_BOOTS(2, 309, Material.IRON_BOOTS),
+    DIAMOND_HELMET(3, 310, Material.DIAMOND_HELMET),
+    DIAMOND_CHESTPLATE(8, 311, Material.DIAMOND_CHESTPLATE),
+    DIAMOND_LEGGINGS(6, 312, Material.DIAMOND_LEGGINGS),
+    DIAMOND_BOOTS(3, 313, Material.DIAMOND_BOOTS),
+    GOLD_HELMET(2, 314, Material.GOLD_HELMET),
+    GOLD_CHESTPLATE(5, 315, Material.GOLD_CHESTPLATE),
+    GOLD_LEGGINGS(3, 316, Material.GOLD_LEGGINGS),
+    GOLD_BOOTS(1, 317, Material.GOLD_BOOTS),
+    NONE(0, 0, Material.AIR);
+
+    private final int armorPoints;
+    private final int id;
+    private final Material type;
+
+    public static ArmorType findByType(Material type) {
+        for(ArmorType a : ArmorType.values())
+            if(a.getType() == type)
+                return a;
+        return ArmorType.NONE;
+    }
+
+    public static int calculateArmorPoints(ItemStack[] armor) {
+        int total = 0;
+        for (ItemStack anArmor : armor) {
+            if (anArmor != null)
+                total += findByType(anArmor.getType()).getArmorPoints();
+        }
+        return total;
+    }
+
+    public static ArmorType findById(int id) {
+        for(ArmorType a : ArmorType.values())
+            if(a.getId() == id)
+                return a;
+        return ArmorType.NONE;
+    }
+
+    public static boolean isArmor(Material material){
+        for(ArmorType a : ArmorType.values())
+            if(a.getType() == material)
+                return true;
+        return false;
+    }
+
+    public static int calculateArmorPoints(int[] armor) {
+        int total = 0;
+        for (int anArmor : armor) {
+            if (anArmor != -1)
+                total += findById(anArmor).getArmorPoints();
+        }
+        return total;
+    }
+
+    public Material getType() {
+        return this.type;
+    }
+
+}

src/main/java/us/myles/ViaVersion/boss/ViaBossBar.java

@@ -0,0 +1,213 @@
+package us.myles.ViaVersion.boss;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import org.apache.commons.lang.Validate;
+import org.bukkit.entity.Player;
+import us.myles.ViaVersion.api.ViaVersion;
+import us.myles.ViaVersion.api.boss.BossBar;
+import us.myles.ViaVersion.api.boss.BossColor;
+import us.myles.ViaVersion.api.boss.BossFlag;
+import us.myles.ViaVersion.api.boss.BossStyle;
+import us.myles.ViaVersion.packets.PacketType;
+import us.myles.ViaVersion.transformers.OutgoingTransformer;
+import us.myles.ViaVersion.util.PacketUtil;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+
+@Getter
+public class ViaBossBar implements BossBar {
+    private UUID uuid;
+    private String title;
+    private float health;
+    private BossColor color;
+    private BossStyle style;
+    private Set<UUID> players;
+    private boolean visible;
+    private Set<BossFlag> flags;
+
+    public ViaBossBar(String title, float health, BossColor color, BossStyle style) {
+        Validate.notNull(title, "Title cannot be null");
+        Validate.isTrue((health >= 0 && health <= 1), "Health must be between 0 and 1");
+        this.uuid = UUID.randomUUID();
+        this.title = title;
+        this.health = health;
+        this.color = color == null ? BossColor.PURPLE : color;
+        this.style = style == null ? BossStyle.SOLID : style;
+        this.players = new HashSet<>();
+        this.flags = new HashSet<>();
+        visible = true;
+    }
+
+    @Override
+    public void setTitle(String title) {
+        Validate.notNull(title, "Title cannot be null");
+        this.title = title;
+        sendPacket(UpdateAction.UPDATE_TITLE);
+    }
+
+    @Override
+    public void setHealth(float health) {
+        Validate.isTrue((health >= 0 && health <= 1), "Health must be between 0 and 1");
+        this.health = health;
+        sendPacket(UpdateAction.UPDATE_HEALTH);
+    }
+
+    @Override
+    public BossColor getColor() {
+        return color;
+    }
+
+    @Override
+    public void setColor(BossColor color) {
+        Validate.notNull(color, "Color cannot be null");
+        this.color = color;
+        sendPacket(UpdateAction.UPDATE_STYLE);
+    }
+
+    @Override
+    public void setStyle(BossStyle style) {
+        Validate.notNull(style, "Style cannot be null");
+        this.style = style;
+        sendPacket(UpdateAction.UPDATE_STYLE);
+    }
+
+    @Override
+    public void addPlayer(Player player) {
+        if (player != null && !players.contains(player.getUniqueId())) {
+            players.add(player.getUniqueId());
+            if (visible)
+                sendPacket(player.getUniqueId(), getPacket(UpdateAction.ADD));
+        }
+    }
+
+    @Override
+    public void removePlayer(Player player) {
+        if (player != null && players.contains(player.getUniqueId())) {
+            players.remove(player.getUniqueId());
+            sendPacket(player.getUniqueId(), getPacket(UpdateAction.REMOVE));
+        }
+    }
+
+    @Override
+    public void addFlag(BossFlag flag) {
+        if (!hasFlag(flag))
+            flags.add(flag);
+        sendPacket(UpdateAction.UPDATE_FLAGS);
+    }
+
+    @Override
+    public void removeFlag(BossFlag flag) {
+        if (hasFlag(flag))
+            flags.remove(flag);
+        sendPacket(UpdateAction.UPDATE_FLAGS);
+    }
+
+    @Override
+    public boolean hasFlag(BossFlag flag) {
+        return flags.contains(flag);
+    }
+
+    @Override
+    public Set<UUID> getPlayers() {
+        return Collections.unmodifiableSet(players);
+    }
+
+    @Override
+    public void show() {
+        setVisible(true);
+    }
+
+    @Override
+    public void hide() {
+        setVisible(false);
+    }
+
+    @Override
+    public boolean isVisible() {
+        return visible;
+    }
+
+    private void setVisible(boolean value) {
+        if (visible != value) {
+            visible = value;
+            sendPacket(value ? UpdateAction.ADD : UpdateAction.REMOVE);
+        }
+    }
+
+    private void sendPacket(UpdateAction action) {
+        ByteBuf buf = getPacket(action);
+        for (UUID uuid : players)
+            sendPacket(uuid, buf);
+    }
+
+    private void sendPacket(UUID uuid, ByteBuf buf) {
+        if (!ViaVersion.getInstance().isPorted(uuid)) {
+            players.remove(uuid);
+            return;
+        }
+        ViaVersion.getInstance().sendRawPacket(uuid, buf);
+    }
+
+    private ByteBuf getPacket(UpdateAction action) {
+        ByteBuf buf = Unpooled.buffer();
+        PacketUtil.writeVarInt(PacketType.PLAY_BOSS_BAR.getNewPacketID(), buf);
+        PacketUtil.writeUUID(uuid, buf);
+        PacketUtil.writeVarInt(action.getId(), buf);
+        switch (action) {
+            case ADD:
+                PacketUtil.writeString(fixJson(title), buf);
+                buf.writeFloat(health);
+                PacketUtil.writeVarInt(color.getId(), buf);
+                PacketUtil.writeVarInt(style.getId(), buf);
+                buf.writeByte(flagToBytes());
+                break;
+            case REMOVE:
+                break;
+            case UPDATE_HEALTH:
+                buf.writeFloat(health);
+                break;
+            case UPDATE_TITLE:
+                PacketUtil.writeString(fixJson(title), buf);
+                break;
+            case UPDATE_STYLE:
+                PacketUtil.writeVarInt(color.getId(), buf);
+                PacketUtil.writeVarInt(style.getId(), buf);
+                break;
+            case UPDATE_FLAGS:
+                buf.writeByte(flagToBytes());
+                break;
+        }
+
+        return buf;
+    }
+
+    private int flagToBytes() {
+        int bitmask = 0;
+        for (BossFlag flag : flags)
+            bitmask |= flag.getId();
+        return bitmask;
+    }
+
+    private String fixJson(String text) {
+        return OutgoingTransformer.fixJson(text);
+    }
+
+    @RequiredArgsConstructor
+    @Getter
+    private enum UpdateAction {
+        ADD(0),
+        REMOVE(1),
+        UPDATE_HEALTH(2),
+        UPDATE_TITLE(3),
+        UPDATE_STYLE(4),
+        UPDATE_FLAGS(5);
+
+        private final int id;
+    }
+}

src/main/java/us/myles/ViaVersion/chunks/ByteWriter.java

@@ -1,52 +0,0 @@
-package us.myles.ViaVersion.chunks;
-
-public class ByteWriter {
-    private final byte[] bytes;
-    private int byteIndex;
-    private int bitIndex;
-
-    public ByteWriter(int size) {
-        this.bytes = new byte[size];
-        this.byteIndex = 0;
-        this.bitIndex = 0;
-    }
-
-    public byte[] getOutput() {
-        return this.bytes;
-    }
-
-    public void writeFullByte(int b){
-        writeByte(b, 8);
-    }
-
-    public void writeByte(int b, int length) {
-        byte current = getCurrentByte();
-        byte byteB = (byte)(int)((b) & 0xff);
-        System.out.println("Input: " + byteB);
-        System.out.println(Integer.toBinaryString(byteB));
-
-        int space = (8 - bitIndex);
-        int written = space > length ? length : space;
-        System.out.println("Written is " + written);
-        bytes[byteIndex] = (byte) (current | (extractRange(byteB, 0, written) >> (bitIndex - 1)));
-        System.out.println("output value: " + bytes[byteIndex]);
-        this.bitIndex += length;
-        if(this.bitIndex >= 8) {
-            this.byteIndex += 1;
-            this.bitIndex = bitIndex - 8;
-            // write remaining into this
-            System.out.println("Writing from " + written + " to " + (written + bitIndex));
-            System.out.println("Value: " + extractRange(byteB, written, written + bitIndex));
-            bytes[byteIndex] = (byte) (extractRange(byteB, written, written + bitIndex) << written);
-        }
-    }
-
-    private byte extractRange(int in, int begin, int end){
-        return (byte) ((in >> begin) & ((1 << (end - begin)) - 1));
-    }
-    public byte getCurrentByte() {
-        if(byteIndex == bytes.length) throw new RuntimeException("ByteWriter overflow!");
-
-        return bytes[byteIndex];
-    }
-}

src/main/java/us/myles/ViaVersion/chunks/Chunk.java

@@ -0,0 +1,32 @@
+package us.myles.ViaVersion.chunks;
+
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor(access = AccessLevel.PROTECTED)
+@Getter
+public class Chunk {
+    private final int x;
+    private final int z;
+    private final boolean groundUp;
+    private final int primaryBitmask;
+    private final ChunkSection[] sections;
+    private final byte[] biomeData;
+    private boolean unloadPacket = false;
+
+    /**
+     * Chunk unload.
+     *
+     * @param x coord
+     * @param z coord
+     */
+    protected Chunk(int x, int z) {
+        this(x, z, true, 0, new ChunkSection[16], null);
+        this.unloadPacket = true;
+    }
+
+    public boolean hasBiomeData() {
+        return biomeData != null && groundUp;
+    }
+}

src/main/java/us/myles/ViaVersion/chunks/ChunkManager.java

@@ -0,0 +1,224 @@
+package us.myles.ViaVersion.chunks;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import org.bukkit.Bukkit;
+import us.myles.ViaVersion.ConnectionInfo;
+import us.myles.ViaVersion.util.PacketUtil;
+import us.myles.ViaVersion.util.ReflectionUtil;
+import us.myles.ViaVersion.util.ReflectionUtil.ClassReflection;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.ShortBuffer;
+import java.util.BitSet;
+import java.util.List;
+import java.util.Set;
+import java.util.logging.Level;
+
+public class ChunkManager {
+    /**
+     * Amount of sections in a chunk.
+     */
+    private static final int SECTION_COUNT = 16;
+    /**
+     * size of each chunk section (16x16x16).
+     */
+    private static final int SECTION_SIZE = 16;
+    /**
+     * Length of biome data.
+     */
+    private static final int BIOME_DATA_LENGTH = 256;
+
+    private final ConnectionInfo info;
+    private final Set<Long> loadedChunks = Sets.newConcurrentHashSet();
+    private final Set<Long> bulkChunks = Sets.newConcurrentHashSet();
+
+    // Reflection
+    private static ClassReflection mapChunkBulkRef;
+    private static ClassReflection mapChunkRef;
+
+    static {
+        try {
+            mapChunkBulkRef = new ClassReflection(ReflectionUtil.nms("PacketPlayOutMapChunkBulk"));
+            mapChunkRef = new ClassReflection(ReflectionUtil.nms("PacketPlayOutMapChunk"));
+        } catch(Exception e) {
+            Bukkit.getLogger().log(Level.WARNING, "Failed to initialise chunk reflection", e);
+        }
+    }
+
+    public ChunkManager(ConnectionInfo info) {
+        this.info = info;
+    }
+
+    /**
+     * Transform a map chunk bulk in to separate map chunk packets.
+     * These packets are registered  so that they will never be seen as unload packets.
+     *
+     * @param packet to transform
+     * @return List of chunk data packets
+     */
+    public List<Object> transformMapChunkBulk(Object packet) {
+        List<Object> list = Lists.newArrayList();
+        try {
+            int[] xcoords = mapChunkBulkRef.getFieldValue("a", packet, int[].class);
+            int[] zcoords = mapChunkBulkRef.getFieldValue("b", packet, int[].class);
+            Object[] chunkMaps = mapChunkBulkRef.getFieldValue("c", packet, Object[].class);
+            for(int i = 0; i < chunkMaps.length; i++) {
+                int x = xcoords[i];
+                int z = zcoords[i];
+                Object chunkMap = chunkMaps[i];
+                Object chunkPacket = mapChunkRef.newInstance();
+                mapChunkRef.setFieldValue("a", chunkPacket, x);
+                mapChunkRef.setFieldValue("b", chunkPacket, z);
+                mapChunkRef.setFieldValue("c", chunkPacket, chunkMap);
+                mapChunkRef.setFieldValue("d", chunkPacket, true); // Chunk bulk chunks are always ground-up
+                bulkChunks.add(toLong(x, z)); // Store for later
+                list.add(chunkPacket);
+            }
+        } catch(Exception e) {
+            Bukkit.getLogger().log(Level.WARNING, "Failed to transform chunk bulk", e);
+        }
+        return list;
+    }
+
+    /**
+     * Read chunk from 1.8 chunk data.
+     *
+     * @param input data
+     * @return Chunk
+     */
+    public Chunk readChunk(ByteBuf input) {
+        // Primary data
+        int chunkX = input.readInt();
+        int chunkZ = input.readInt();
+        long chunkHash = toLong(chunkX, chunkZ);
+        boolean groundUp = input.readByte() != 0;
+        int bitmask = input.readUnsignedShort();
+        int dataLength = PacketUtil.readVarInt(input);
+
+        // Data to be read
+        BitSet usedSections = new BitSet(16);
+        ChunkSection[] sections = new ChunkSection[16];
+        byte[] biomeData = null;
+
+        // Calculate section count from bitmask
+        for(int i = 0; i < 16; i++) {
+            if((bitmask & (1 << i)) != 0) {
+                usedSections.set(i);
+            }
+        }
+        int sectionCount = usedSections.cardinality(); // the amount of sections set
+
+        // If the chunk is from a chunk bulk, it is never an unload packet
+        // Other wise, if it has no data, it is :)
+        boolean isBulkPacket = bulkChunks.remove(chunkHash);
+        if(sectionCount == 0 && groundUp && !isBulkPacket && loadedChunks.contains(chunkHash)) {
+            // This is a chunk unload packet
+            loadedChunks.remove(chunkHash);
+            return new Chunk(chunkX, chunkZ);
+        }
+
+        int startIndex = input.readerIndex();
+        loadedChunks.add(chunkHash); // mark chunk as loaded
+
+        // Read blocks
+        for(int i = 0; i < SECTION_COUNT; i++) {
+            if(!usedSections.get(i)) continue; // Section not set
+            ChunkSection section = new ChunkSection();
+            sections[i] = section;
+
+            // Read block data and convert to short buffer
+            byte[] blockData = new byte[ChunkSection.SIZE * 2];
+            input.readBytes(blockData);
+            ShortBuffer blockBuf = ByteBuffer.wrap(blockData).order(ByteOrder.LITTLE_ENDIAN).asShortBuffer();
+
+            for(int j = 0; j < ChunkSection.SIZE; j++) {
+                int mask = blockBuf.get();
+                int type = mask >> 4;
+                int data = mask & 0xF;
+                section.setBlock(j, type, data);
+            }
+        }
+
+        // Read block light
+        for(int i = 0; i < SECTION_COUNT; i++) {
+            if(!usedSections.get(i)) continue; // Section not set, has no light
+            byte[] blockLightArray = new byte[ChunkSection.LIGHT_LENGTH];
+            input.readBytes(blockLightArray);
+            sections[i].setBlockLight(blockLightArray);
+        }
+
+        // Read sky light
+        int bytesLeft = dataLength - (input.readerIndex() - startIndex);
+        if(bytesLeft >= ChunkSection.LIGHT_LENGTH) {
+            for(int i = 0; i < SECTION_COUNT; i++) {
+                if(!usedSections.get(i)) continue; // Section not set, has no light
+                byte[] skyLightArray = new byte[ChunkSection.LIGHT_LENGTH];
+                input.readBytes(skyLightArray);
+                sections[i].setSkyLight(skyLightArray);
+                bytesLeft -= ChunkSection.LIGHT_LENGTH;
+            }
+        }
+
+        // Read biome data
+        if(bytesLeft >= BIOME_DATA_LENGTH) {
+            biomeData = new byte[BIOME_DATA_LENGTH];
+            input.readBytes(biomeData);
+            bytesLeft -= BIOME_DATA_LENGTH;
+        }
+
+        // Check remaining bytes
+        if(bytesLeft > 0) {
+            Bukkit.getLogger().log(Level.WARNING, bytesLeft + " Bytes left after reading chunk! (" + groundUp + ")");
+        }
+
+        // Return chunk
+        return new Chunk(chunkX, chunkZ, groundUp, bitmask, sections, biomeData);
+    }
+
+    /**
+     * Write chunk over 1.9 protocol.
+     *
+     * @param chunk chunk
+     * @param output output
+     */
+    public void writeChunk(Chunk chunk, ByteBuf output) {
+        if(chunk.isUnloadPacket()) {
+            output.clear();
+            PacketUtil.writeVarInt(0x1D, output);
+        }
+
+        // Write primary info
+        output.writeInt(chunk.getX());
+        output.writeInt(chunk.getZ());
+        if(chunk.isUnloadPacket()) return;
+        output.writeByte(chunk.isGroundUp() ? 0x01 : 0x00);
+        PacketUtil.writeVarInt(chunk.getPrimaryBitmask(), output);
+
+        ByteBuf buf = Unpooled.buffer();
+        for(int i = 0; i < SECTION_COUNT; i++) {
+            ChunkSection section = chunk.getSections()[i];
+            if(section == null) continue; // Section not set
+            section.writeBlocks(buf);
+            section.writeBlockLight(buf);
+            if(!section.hasSkyLight()) continue; // No sky light, we're done here.
+            section.writeSkyLight(buf);
+        }
+        buf.readerIndex(0);
+        PacketUtil.writeVarInt(buf.readableBytes() + (chunk.hasBiomeData() ? 256 : 0), output);
+        output.writeBytes(buf);
+        buf.release(); // release buffer
+
+        // Write biome data
+        if(chunk.hasBiomeData()) {
+            output.writeBytes(chunk.getBiomeData());
+        }
+    }
+
+    private static long toLong(int msw, int lsw)  {
+        return ((long) msw << 32) + lsw - -2147483648L;
+    }
+}

src/main/java/us/myles/ViaVersion/chunks/ChunkSection.java

@@ -0,0 +1,143 @@
+package us.myles.ViaVersion.chunks;
+
+import com.google.common.collect.Lists;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import org.bukkit.Material;
+import us.myles.ViaVersion.util.PacketUtil;
+
+import java.util.List;
+
+public class ChunkSection {
+    /**
+     * Size (dimensions) of blocks in a chunk section.
+     */
+    public static final int SIZE = 16 * 16 * 16; // width * depth * height
+    /**
+     * Length of the sky and block light nibble arrays.
+     */
+    public static final int LIGHT_LENGTH = 16 * 16 * 16 / 2; // size * size * size / 2 (nibble bit count)
+    /**
+     * Length of the block data array.
+     */
+//    public static final int BLOCK_LENGTH = 16 * 16 * 16 * 2; // size * size * size * 2 (char bit count)
+
+    private final List<Integer> palette = Lists.newArrayList();
+    private final int[] blocks;
+    private final NibbleArray blockLight;
+    private NibbleArray skyLight;
+
+    public ChunkSection() {
+        this.blocks = new int[SIZE];
+        this.blockLight = new NibbleArray(SIZE);
+        palette.add(0); // AIR
+    }
+
+    public void setBlock(int x, int y, int z, int type, int data) {
+        setBlock(index(x, y, z), type, data);
+    }
+
+    public void setBlock(int idx, int type, int data) {
+        int hash = type << 4 | (data & 0xF);
+        int index = palette.indexOf(hash);
+        if(index == -1) {
+            index = palette.size();
+            palette.add(hash);
+        }
+
+        blocks[idx] = index;
+    }
+
+    public void setBlockLight(byte[] data) {
+        blockLight.setHandle(data);
+    }
+
+    public void setSkyLight(byte[] data) {
+        if(data.length != LIGHT_LENGTH) throw new IllegalArgumentException("Data length != " + LIGHT_LENGTH);
+        this.skyLight = new NibbleArray(data);
+    }
+
+    private int index(int x, int y, int z) {
+        return z << 8 | y << 4 | x;
+    }
+
+    public void writeBlocks(ByteBuf output) {
+        // Write bits per block
+        int bitsPerBlock = 4;
+        while(palette.size() > 1 << bitsPerBlock) {
+            bitsPerBlock += 1;
+        }
+        long maxEntryValue = (1L << bitsPerBlock) - 1;
+        output.writeByte(bitsPerBlock);
+
+        // Write pallet (or not)
+        PacketUtil.writeVarInt(palette.size(), output);
+        for(int mappedId : palette) {
+            PacketUtil.writeVarInt(mappedId, output);
+        }
+
+        int length = (int) Math.ceil(SIZE * bitsPerBlock / 64.0);
+        PacketUtil.writeVarInt(length, output);
+        long[] data = new long[length];
+        for(int index = 0; index < blocks.length; index++) {
+            int value = blocks[index];
+            int bitIndex = index * bitsPerBlock;
+            int startIndex = bitIndex / 64;
+            int endIndex = ((index + 1) * bitsPerBlock - 1) / 64;
+            int startBitSubIndex = bitIndex % 64;
+            data[startIndex] = data[startIndex] & ~(maxEntryValue << startBitSubIndex) | ((long) value & maxEntryValue) << startBitSubIndex;
+            if(startIndex != endIndex) {
+                int endBitSubIndex = 64 - startBitSubIndex;
+                data[endIndex] = data[endIndex] >>> endBitSubIndex << endBitSubIndex | ((long) value & maxEntryValue) >> endBitSubIndex;
+            }
+        }
+        PacketUtil.writeLongs(data, output);
+    }
+
+    public void writeBlockLight(ByteBuf output) {
+        output.writeBytes(blockLight.getHandle());
+    }
+
+    public void writeSkyLight(ByteBuf output) {
+        output.writeBytes(skyLight.getHandle());
+    }
+
+    public boolean hasSkyLight() {
+        return skyLight != null;
+    }
+
+    /**
+     * Get expected size of this chunk section.
+     *
+     * @return Amount of bytes sent by this section
+     */
+    public int getExpectedSize() {
+        int bitsPerBlock = palette.size() > 255 ? 16 : 8;
+        int bytes = 1; // bits per block
+        bytes += paletteBytes(); // palette
+        bytes += countBytes(bitsPerBlock == 16 ? SIZE * 2 : SIZE); // block data length
+        bytes += (palette.size() > 255 ? 2 : 1) * SIZE; // block data
+        bytes += LIGHT_LENGTH; // block light
+        bytes += hasSkyLight() ? LIGHT_LENGTH : 0; // sky light
+        return bytes;
+    }
+
+    private int paletteBytes() {
+        // Count bytes used by pallet
+        int bytes = countBytes(palette.size());
+        for(int mappedId : palette) {
+            bytes += countBytes(mappedId);
+        }
+        return bytes;
+    }
+
+    private int countBytes(int value) {
+        // Count amount of bytes that would be sent if the value were sent as a VarInt
+        ByteBuf buf = Unpooled.buffer();
+        PacketUtil.writeVarInt(value, buf);
+        buf.readerIndex(0);
+        int bitCount = buf.readableBytes();
+        buf.release();
+        return bitCount;
+    }
+}

src/main/java/us/myles/ViaVersion/chunks/MagicBitSet.java

@@ -1,16 +0,0 @@
-package us.myles.ViaVersion.chunks;
-
-import java.util.BitSet;
-
-public class MagicBitSet extends BitSet{
-    private final int initLength;
-
-    public MagicBitSet(int nbits) {
-        super(nbits);
-        this.initLength = nbits;
-    }
-
-    public int getTrueLength() {
-        return length() == 0 ? initLength : length();
-    }
-}

src/main/java/us/myles/ViaVersion/chunks/NibbleArray.java

@@ -0,0 +1,74 @@
+package us.myles.ViaVersion.chunks;
+
+import java.util.Arrays;
+
+public class NibbleArray {
+    private final byte[] handle;
+
+    public NibbleArray(int length) {
+        if(length == 0 || length % 2 != 0) {
+            throw new IllegalArgumentException("Length of nibble array must be a positive number dividable by 2!");
+        }
+
+        this.handle = new byte[length / 2];
+    }
+
+    public NibbleArray(byte[] handle) {
+        if(handle.length == 0 || handle.length % 2 != 0) {
+            throw new IllegalArgumentException("Length of nibble array must be a positive number dividable by 2!");
+        }
+
+        this.handle = handle;
+    }
+
+    public byte get(int x, int y, int z) {
+        return get(y << 8 | z << 4 | x);
+    }
+
+    public byte get(int index) {
+        byte value = handle[index / 2];
+        if(index % 2 == 0) {
+            return (byte) (value & 0xF);
+        } else {
+            return (byte) ((value >> 4) & 0xF);
+        }
+    }
+
+    public void set(int x, int y, int z, int value) {
+        set(y << 8 | z << 4 | x, value);
+    }
+
+    public void set(int index, int value) {
+        index /= 2;
+        if(index % 2 == 0) {
+            handle[index] = (byte) (handle[index] & 0xF0 | value & 0xF);
+        } else {
+            handle[index] = (byte) (handle[index] & 0xF | (value & 0xF) << 4);
+        }
+    }
+
+    public int size() {
+        return handle.length * 2;
+    }
+
+    public int actualSize() {
+        return handle.length;
+    }
+
+    public void fill(byte value) {
+        value &= 0xF; // Max nibble size (= 16)
+        Arrays.fill(handle, (byte) ((value << 4) | value));
+    }
+
+    public void setHandle(byte[] handle) {
+        if(handle.length != this.handle.length) {
+            throw new IllegalArgumentException("Length of handle must equal to size of nibble array!");
+        }
+
+        System.arraycopy(handle, 0, this.handle, 0, handle.length);
+    }
+
+    public byte[] getHandle() {
+        return handle;
+    }
+}

src/main/java/us/myles/ViaVersion/chunks/PacketChunk.java

@@ -1,19 +0,0 @@
-package us.myles.ViaVersion.chunks;
-
-public class PacketChunk {
-    private PacketChunkData[] chunkData;
-    private byte[] biomeData;
-
-    public PacketChunk(PacketChunkData[] chunkData, byte[] biomeData) {
-        this.chunkData = chunkData;
-        this.biomeData = biomeData;
-    }
-
-    public PacketChunkData[] getChunkData() {
-        return chunkData;
-    }
-
-    public byte[] getBiomeData() {
-        return biomeData;
-    }
-}

src/main/java/us/myles/ViaVersion/chunks/PacketChunkData.java

@@ -1,25 +0,0 @@
-package us.myles.ViaVersion.chunks;
-
-public class PacketChunkData {
-    private short[] blocks = new short[4096];
-    private byte[] blockLight = new byte[2048];
-    private byte[] skyLight;
-
-    public PacketChunkData(boolean isSkyLightData) {
-        if(isSkyLightData){
-            skyLight = new byte[2048];
-        }
-    }
-
-    public short[] getBlocks() {
-        return this.blocks;
-    }
-
-    public byte[] getBlockLight() {
-        return this.blockLight;
-    }
-
-    public byte[] getSkyLight() {
-        return this.skyLight;
-    }
-}

src/main/java/us/myles/ViaVersion/commands/ViaVersionCommand.java

@@ -0,0 +1,77 @@
+package us.myles.ViaVersion.commands;
+
+import lombok.RequiredArgsConstructor;
+import org.bukkit.Bukkit;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+import us.myles.ViaVersion.ViaVersionPlugin;
+import us.myles.ViaVersion.api.ViaVersion;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Created by fillefilip8 on 2016-03-03.
+ */
+@RequiredArgsConstructor
+public class ViaVersionCommand implements CommandExecutor {
+
+    private final ViaVersionPlugin plugin;
+
+    @Override
+    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
+        if (sender.hasPermission("viaversion.admin")) {
+            if (args.length == 0) {
+                sendHelp(sender);
+            } else if (args.length == 1) {
+                if (args[0].equalsIgnoreCase("list")) {
+                    List<String> portedPlayers = new ArrayList<>();
+                    List<String> normalPlayers = new ArrayList<>();
+                    for (Player p : Bukkit.getOnlinePlayers()) {
+                        if (ViaVersion.getInstance().isPorted(p)) {
+                            portedPlayers.add(p.getName());
+                        } else {
+                            normalPlayers.add(p.getName());
+                        }
+                    }
+
+                    sender.sendMessage(color("&8[&61.9&8]: &b" + portedPlayers.toString()));
+                    sender.sendMessage(color("&8[&61.8&8]: &b" + normalPlayers.toString()));
+                } else if (args[0].equalsIgnoreCase("debug")) {
+                    plugin.setDebug(!plugin.isDebug());
+                    sender.sendMessage(color("&6Debug mode is now " + (plugin.isDebug() ? "&aenabled" : "&cdisabled")));
+                } else if (args[0].equalsIgnoreCase("dontbugme")) {
+                    boolean newValue = !plugin.getConfig().getBoolean("checkforupdates", true);
+                    plugin.getConfig().set("checkforupdates", newValue);
+                    plugin.saveConfig();
+                    sender.sendMessage(color("&6We will " + (newValue ? "&anotify you about updates." : "&cnot tell you about updates.")));
+                } else if (args[0].equalsIgnoreCase("autoteam")) {
+                    boolean newValue = !plugin.getConfig().getBoolean("auto-team", true);
+                    plugin.getConfig().set("auto-team", newValue);
+                    plugin.saveConfig();
+                    sender.sendMessage(color("&6We will " + (newValue ? "&aautomatically team players" : "&cno longer auto team players")));
+                    sender.sendMessage(color("&6All players will need to re-login for the change to take place."));
+                } else {
+                    sendHelp(sender);
+                }
+            }
+
+        }
+        return false;
+    }
+
+    public void sendHelp(CommandSender sender){
+        sender.sendMessage(color("&aViaVersion &c" + ViaVersion.getInstance().getVersion()));
+        sender.sendMessage(color("&6Commands:"));
+        sender.sendMessage(color("&2/viaversion list &7- &6Shows lists of all 1.9 clients and 1.8 clients."));
+        sender.sendMessage(color("&2/viaversion debug &7- &6Toggle debug mode"));
+        sender.sendMessage(color("&2/viaversion autoteam &7- &6Toggle automatically teaming to prevent colliding."));
+        sender.sendMessage(color("&2/viaversion dontbugme &7- &6Toggle checking for updates."));
+    }
+
+    public String color(String string) {
+        return string.replace("&", "§");
+    }
+}

src/main/java/us/myles/ViaVersion/handlers/ViaChunkHandler.java

@@ -0,0 +1,36 @@
+package us.myles.ViaVersion.handlers;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.MessageToMessageEncoder;
+import us.myles.ViaVersion.ConnectionInfo;
+import us.myles.ViaVersion.util.ReflectionUtil;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.List;
+
+public class ViaChunkHandler extends MessageToMessageEncoder {
+    private final ConnectionInfo info;
+
+    public ViaChunkHandler(ConnectionInfo info) {
+        this.info = info;
+    }
+
+    @Override
+    protected void encode(ChannelHandlerContext ctx, Object o, List list) throws Exception {
+        // Split chunk bulk packet up in to single chunk packets before it reached the encoder.
+        // This will prevent issues with several plugins and other protocol handlers due to the chunk being sent twice.
+        // It also sends the chunk in the right order possible resolving some issues with added chunk/block/entity data.
+        if (!(o instanceof ByteBuf)) {
+            info.setLastPacket(o);
+            /* This transformer is more for fixing issues which we find hard at packet level :) */
+            if(o.getClass().getName().endsWith("PacketPlayOutMapChunkBulk") && info.isActive()) {
+                list.addAll(info.getChunkManager().transformMapChunkBulk(o));
+                return;
+            }
+        }
+
+        list.add(o);
+    }
+}

src/main/java/us/myles/ViaVersion/handlers/ViaDecodeHandler.java

@@ -0,0 +1,52 @@
+package us.myles.ViaVersion.handlers;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.ByteToMessageDecoder;
+import us.myles.ViaVersion.CancelException;
+import us.myles.ViaVersion.ConnectionInfo;
+import us.myles.ViaVersion.transformers.IncomingTransformer;
+import us.myles.ViaVersion.util.PacketUtil;
+
+import java.util.List;
+
+public class ViaDecodeHandler extends ByteToMessageDecoder {
+
+    private final IncomingTransformer incomingTransformer;
+    private final ByteToMessageDecoder minecraftDecoder;
+    private final ConnectionInfo info;
+
+    public ViaDecodeHandler(ConnectionInfo info, ByteToMessageDecoder minecraftDecoder) {
+        this.info = info;
+        this.minecraftDecoder = minecraftDecoder;
+        this.incomingTransformer = new IncomingTransformer(info);
+    }
+
+    @Override
+    protected void decode(ChannelHandlerContext ctx, ByteBuf bytebuf, List<Object> list) throws Exception {
+        // use transformers
+        if (bytebuf.readableBytes() > 0) {
+            if (info.isActive()) {
+                int id = PacketUtil.readVarInt(bytebuf);
+                // Transform
+                ByteBuf newPacket = ctx.alloc().buffer();
+                try {
+                    incomingTransformer.transform(id, bytebuf, newPacket);
+                    bytebuf.clear();
+                    bytebuf = newPacket;
+                } catch (Exception e) {
+                    bytebuf.clear();
+                    throw e;
+                }
+            }
+            // call minecraft decoder
+            list.addAll(PacketUtil.callDecode(this.minecraftDecoder, ctx, bytebuf));
+        }
+    }
+
+    @Override
+    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+        if (PacketUtil.containsCause(cause, CancelException.class)) return;
+        super.exceptionCaught(ctx, cause);
+    }
+}

src/main/java/us/myles/ViaVersion/handlers/ViaEncodeHandler.java

@@ -0,0 +1,58 @@
+package us.myles.ViaVersion.handlers;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.MessageToByteEncoder;
+import us.myles.ViaVersion.CancelException;
+import us.myles.ViaVersion.ConnectionInfo;
+import us.myles.ViaVersion.transformers.OutgoingTransformer;
+import us.myles.ViaVersion.util.PacketUtil;
+import us.myles.ViaVersion.util.ReflectionUtil;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+public class ViaEncodeHandler extends MessageToByteEncoder {
+    private final ConnectionInfo info;
+    private final MessageToByteEncoder minecraftEncoder;
+    private final OutgoingTransformer outgoingTransformer;
+
+    public ViaEncodeHandler(ConnectionInfo info, MessageToByteEncoder minecraftEncoder) {
+        this.info = info;
+        this.minecraftEncoder = minecraftEncoder;
+        this.outgoingTransformer = new OutgoingTransformer(info);
+    }
+
+
+    @Override
+    protected void encode(final ChannelHandlerContext ctx, Object o, final ByteBuf bytebuf) throws Exception {
+        // handle the packet type
+        if (!(o instanceof ByteBuf)) {
+            // call minecraft encoder
+            PacketUtil.callEncode(this.minecraftEncoder, ctx, o, bytebuf);
+        }
+        if (bytebuf.readableBytes() == 0) {
+            throw new CancelException();
+        }
+        if (info.isActive()) {
+            int id = PacketUtil.readVarInt(bytebuf);
+            // Transform
+            ByteBuf oldPacket = bytebuf.copy();
+            bytebuf.clear();
+            try {
+                outgoingTransformer.transform(id, oldPacket, bytebuf);
+            } catch (Exception e) {
+                bytebuf.clear();
+                throw e;
+            } finally {
+                oldPacket.release();
+            }
+        }
+    }
+
+    @Override
+    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+        if (PacketUtil.containsCause(cause, CancelException.class)) return;
+        super.exceptionCaught(ctx, cause);
+    }
+}

src/main/java/us/myles/ViaVersion/handlers/ViaInboundHandler.java

@@ -1,53 +0,0 @@
-package us.myles.ViaVersion.handlers;
-
-import io.netty.buffer.ByteBuf;
-import io.netty.channel.Channel;
-import io.netty.channel.ChannelHandler;
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
-import us.myles.ViaVersion.CancelException;
-import us.myles.ViaVersion.ConnectionInfo;
-import us.myles.ViaVersion.PacketUtil;
-import us.myles.ViaVersion.transformers.IncomingTransformer;
-
-@ChannelHandler.Sharable
-public class ViaInboundHandler extends ChannelInboundHandlerAdapter {
-    private final IncomingTransformer incomingTransformer;
-    private final ViaVersionInitializer init;
-
-    public ViaInboundHandler(Channel c, ConnectionInfo info, ViaVersionInitializer init) {
-        this.init = init;
-        this.incomingTransformer = new IncomingTransformer(c, info, init);
-    }
-
-    @Override
-    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
-        boolean compression = ctx.pipeline().get("compress") != null;
-
-        if (msg instanceof ByteBuf) {
-            ByteBuf bytebuf = (ByteBuf) msg;
-            if (compression) {
-                // decompress :)
-                bytebuf = PacketUtil.decompress(ctx, bytebuf);
-            }
-            int id = PacketUtil.readVarInt(bytebuf);
-            // Transform
-            ByteBuf newPacket = ctx.alloc().buffer();
-            try {
-                incomingTransformer.transform(id, bytebuf, newPacket);
-            } catch (CancelException e) {
-                return;
-            } finally {
-                bytebuf.release();
-            }
-            if (compression) {
-                // recompress :)
-                newPacket = PacketUtil.compress(ctx, newPacket);
-            }
-            msg = newPacket;
-        }
-        super.channelRead(ctx, msg);
-    }
-
-
-}

src/main/java/us/myles/ViaVersion/handlers/ViaOutboundHandler.java

@@ -1,53 +0,0 @@
-package us.myles.ViaVersion.handlers;
-
-import io.netty.buffer.ByteBuf;
-import io.netty.channel.*;
-import us.myles.ViaVersion.CancelException;
-import us.myles.ViaVersion.ConnectionInfo;
-import us.myles.ViaVersion.PacketUtil;
-import us.myles.ViaVersion.transformers.OutgoingTransformer;
-
-@ChannelHandler.Sharable
-public class ViaOutboundHandler extends ChannelOutboundHandlerAdapter {
-    private final OutgoingTransformer outgoingTransformer;
-    private final ViaVersionInitializer init;
-
-    public ViaOutboundHandler(Channel c, ConnectionInfo info, ViaVersionInitializer init) {
-        this.init = init;
-        this.outgoingTransformer = new OutgoingTransformer(c, info, init);
-    }
-
-    @Override
-    public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise channelPromise) throws Exception {
-        try {
-            if (channelPromise.isDone()) return; // don't break any <3s
-            boolean compression = ctx.pipeline().get("compress") != null;
-            if (msg instanceof ByteBuf) {
-                ByteBuf bytebuf = (ByteBuf) msg;
-                if (compression) {
-                    // decompress :)
-                    bytebuf = PacketUtil.decompress(ctx, bytebuf);
-                }
-                int id = PacketUtil.readVarInt(bytebuf);
-                // Transform
-                ByteBuf newPacket = ctx.alloc().buffer();
-                try {
-                    outgoingTransformer.transform(id, bytebuf, newPacket);
-                } catch (CancelException e) {
-                    return;
-                } finally {
-                    bytebuf.release();
-                }
-                if (compression) {
-                    // recompress :)
-                    newPacket = PacketUtil.compress(ctx, newPacket);
-                }
-                msg = newPacket;
-            }
-            super.write(ctx, msg, channelPromise);
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-    }
-
-}

src/main/java/us/myles/ViaVersion/handlers/ViaOutboundPacketHandler.java

@@ -1,43 +0,0 @@
-package us.myles.ViaVersion.handlers;
-
-import io.netty.buffer.ByteBuf;
-import io.netty.channel.*;
-import us.myles.ViaVersion.ConnectionInfo;
-import us.myles.ViaVersion.ReflectionUtil;
-
-import java.lang.reflect.Constructor;
-
-@ChannelHandler.Sharable
-public class ViaOutboundPacketHandler extends ChannelOutboundHandlerAdapter {
-    private final ConnectionInfo info;
-
-    public ViaOutboundPacketHandler(Channel c, ConnectionInfo info) {
-        this.info = info;
-    }
-
-    @Override
-    public void write(ChannelHandlerContext channelHandlerContext, Object o, ChannelPromise channelPromise) throws Exception {
-        if (!(o instanceof ByteBuf)) {
-            info.setLastPacket(o);
-            /* This transformer is more for fixing issues which we find hard at byte level :) */
-            if (o.getClass().getName().endsWith("PacketPlayOutMapChunkBulk")) {
-                int[] locX = ReflectionUtil.get(o, "a", int[].class);
-                int[] locZ = ReflectionUtil.get(o, "b", int[].class);
-
-                Object world = ReflectionUtil.get(o, "world", ReflectionUtil.nms("World"));
-                Class<?> mapChunk = ReflectionUtil.nms("PacketPlayOutMapChunk");
-                Constructor constructor = mapChunk.getDeclaredConstructor(ReflectionUtil.nms("Chunk"), boolean.class, int.class);
-                for (int i = 0; i < locX.length; i++) {
-                    int x = locX[i];
-                    int z = locZ[i];
-                    // world invoke function
-                    Object chunk = ReflectionUtil.nms("World").getDeclaredMethod("getChunkAt", int.class, int.class).invoke(world, x, z);
-                    Object packet = constructor.newInstance(chunk, true, 65535);
-                    channelHandlerContext.write(packet);
-                }
-                return;
-            }
-        }
-        super.write(channelHandlerContext, o, channelPromise);
-    }
-}

src/main/java/us/myles/ViaVersion/handlers/ViaVersionInitializer.java

@@ -3,18 +3,16 @@ package us.myles.ViaVersion.handlers;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.socket.SocketChannel;
+import io.netty.handler.codec.ByteToMessageDecoder;
+import io.netty.handler.codec.MessageToByteEncoder;
 import us.myles.ViaVersion.ConnectionInfo;
 
 import java.lang.reflect.Method;
 
 public class ViaVersionInitializer extends ChannelInitializer<SocketChannel> {
+
     private final ChannelInitializer<SocketChannel> oldInit;
     private Method method;
-    private ConnectionInfo info;
-    private ViaInboundHandler inbound;
-    private ViaOutboundHandler outbound;
-    private SocketChannel socketChannel;
-    private ViaOutboundPacketHandler outbound2;
 
     public ViaVersionInitializer(ChannelInitializer<SocketChannel> oldInit) {
         this.oldInit = oldInit;
@@ -28,24 +26,16 @@ public class ViaVersionInitializer extends ChannelInitializer<SocketChannel> {
 
     @Override
     protected void initChannel(SocketChannel socketChannel) throws Exception {
-        info = new ConnectionInfo();
+        ConnectionInfo info = new ConnectionInfo(socketChannel);
         // Add originals
         this.method.invoke(this.oldInit, socketChannel);
         // Add our transformers
-        this.socketChannel = socketChannel;
-        this.inbound = new ViaInboundHandler(socketChannel, info, this);
-        this.outbound = new ViaOutboundHandler(socketChannel, info, this);
-        this.outbound2 = new ViaOutboundPacketHandler(socketChannel, info);
-        socketChannel.pipeline().addBefore("decoder", "via_incoming", this.inbound);
-        socketChannel.pipeline().addBefore("packet_handler", "via_outgoing2", this.outbound2);
-        socketChannel.pipeline().addBefore("encoder", "via_outgoing", this.outbound);
+        ViaEncodeHandler encoder = new ViaEncodeHandler(info, (MessageToByteEncoder) socketChannel.pipeline().get("encoder"));
+        ViaDecodeHandler decoder = new ViaDecodeHandler(info, (ByteToMessageDecoder) socketChannel.pipeline().get("decoder"));
+        ViaChunkHandler chunkHandler = new ViaChunkHandler(info);
 
+        socketChannel.pipeline().replace("encoder", "encoder", encoder);
+        socketChannel.pipeline().replace("decoder", "decoder", decoder);
+        socketChannel.pipeline().addAfter("packet_handler", "viaversion_chunk_handler", chunkHandler);
     }
-
-    public void remove(){
-        socketChannel.pipeline().remove("via_incoming");
-        socketChannel.pipeline().remove("via_outgoing");
-        socketChannel.pipeline().remove("via_outgoing2");
-    }
-
 }

src/main/java/us/myles/ViaVersion/listeners/CommandBlockListener.java

@@ -0,0 +1,62 @@
+package us.myles.ViaVersion.listeners;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import lombok.RequiredArgsConstructor;
+import org.bukkit.block.Block;
+import org.bukkit.block.CommandBlock;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.block.Action;
+import org.bukkit.event.player.PlayerInteractEvent;
+import org.bukkit.event.player.PlayerJoinEvent;
+import us.myles.ViaVersion.ViaVersionPlugin;
+import us.myles.ViaVersion.packets.PacketType;
+import us.myles.ViaVersion.util.PacketUtil;
+import us.myles.ViaVersion.util.ReflectionUtil;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+@RequiredArgsConstructor
+public class CommandBlockListener implements Listener {
+
+    private final ViaVersionPlugin plugin;
+
+    @EventHandler(ignoreCancelled = true, priority = EventPriority.MONITOR)
+    public void onJoin(final PlayerJoinEvent e) {
+        if (e.getPlayer().isOp() && plugin.isPorted(e.getPlayer())) {
+            ByteBuf buf = Unpooled.buffer();
+            PacketUtil.writeVarInt(PacketType.PLAY_ENTITY_STATUS.getNewPacketID(), buf);
+            buf.writeInt(e.getPlayer().getEntityId());
+            buf.writeByte(26);
+            plugin.sendRawPacket(e.getPlayer(), buf);
+        }
+    }
+
+    @EventHandler(ignoreCancelled = true)
+    public void onInteract(PlayerInteractEvent e) {
+        if (e.getAction() == Action.RIGHT_CLICK_BLOCK && plugin.isPorted(e.getPlayer()) && e.getPlayer().isOp()) {
+            try {
+                sendCommandBlockPacket(e.getClickedBlock(), e.getPlayer());
+            } catch (NoSuchFieldException | IllegalAccessException | InvocationTargetException | NoSuchMethodException | ClassNotFoundException e1) {
+                e1.printStackTrace();
+            }
+        }
+    }
+
+    private void sendCommandBlockPacket(Block b, Player player) throws NoSuchFieldException, IllegalAccessException, NoSuchMethodException, InvocationTargetException, ClassNotFoundException {
+        if (!(b.getState() instanceof CommandBlock))
+            return;
+        CommandBlock cmd = (CommandBlock) b.getState();
+
+        Object tileEntityCommand = ReflectionUtil.get(cmd, "commandBlock", ReflectionUtil.nms("TileEntityCommand"));
+        Object updatePacket = ReflectionUtil.invoke(tileEntityCommand, "getUpdatePacket");
+        Object nmsPlayer = ReflectionUtil.invoke(player, "getHandle");
+        Object playerConnection = ReflectionUtil.get(nmsPlayer, "playerConnection", ReflectionUtil.nms("PlayerConnection"));
+        Method sendPacket = playerConnection.getClass().getMethod("sendPacket", ReflectionUtil.nms("Packet"));
+        sendPacket.invoke(playerConnection, updatePacket); //Let the transformer do the work
+    }
+}

src/main/java/us/myles/ViaVersion/metadata/MetaIndex.java

@@ -1,198 +1,191 @@
-package us.myles.ViaVersion.metadata;
-
-import org.bukkit.entity.*;
-
-public enum MetaIndex {
-
-    // entity
-    ENTITY_STATUS(org.bukkit.entity.Entity.class, 0, Type.Byte, NewType.Byte),
-    ENTITY_AIR(org.bukkit.entity.Entity.class, 1, Type.Short, NewType.VarInt),
-    ENTITY_SILENT(org.bukkit.entity.Entity.class, 4, Type.Byte, NewType.Boolean),
-    // living entity
-    LIVINGENTITY_NAMETAG(LivingEntity.class, 2, Type.String, NewType.String),
-    LIVINGENTITY_ALWAYS_SHOW_NAMETAG(LivingEntity.class, 3, Type.Byte, NewType.Boolean),
-    LIVINGENTITY_HEALTH(LivingEntity.class, 6, Type.Float, NewType.Float),
-    LIVINGENTITY_POTION_EFFECT_COLOR(LivingEntity.class, 7, Type.Int, NewType.VarInt),
-    LIVINGENTITY_IS_POTION_AMBIENT(LivingEntity.class, 8, Type.Byte, NewType.Boolean),
-    LIVINGENTITY_NUMBER_OF_ARROWS_IN(LivingEntity.class, 9, Type.Byte, NewType.VarInt),
-    LIVINGENTITY_NO_AI(LivingEntity.class, 15, Type.Byte, 10, NewType.Byte), // in 1.9 this is combined with Left handed, oh.
-    // ageable
-    AGEABLE_AGE(Ageable.class, 12, Type.Byte, 11, NewType.Boolean),
-    // armour stand
-    STAND_INFO(ArmorStand.class, 10, Type.Byte, NewType.Byte),
-    STAND_HEAD_POS(ArmorStand.class, 11, Type.Rotation, NewType.Vector3F),
-    STAND_BODY_POS(ArmorStand.class, 12, Type.Rotation, NewType.Vector3F),
-    STAND_LA_POS(ArmorStand.class, 13, Type.Rotation, NewType.Vector3F),
-    STAND_RA_POS(ArmorStand.class, 14, Type.Rotation, NewType.Vector3F),
-    STAND_LL_POS(ArmorStand.class, 15, Type.Rotation, NewType.Vector3F),
-    STAND_RL_POS(ArmorStand.class, 16, Type.Rotation, NewType.Vector3F),
-    // human, discountined?
-    PLAYER_SKIN_FLAGS(HumanEntity.class, 10, Type.Byte, NewType.Discontinued), // unsigned on 1.8
-    PLAYER_HUMAN_BYTE(HumanEntity.class, 16, Type.Byte, NewType.Discontinued), // unused on 1.8
-    PLAYER_ADDITIONAL_HEARTS(HumanEntity.class, 17, Type.Float, NewType.Discontinued),
-    PLAYER_SCORE(HumanEntity.class, 18, Type.Int, NewType.Discontinued),
-    // horse
-    HORSE_INFO(Horse.class, 16, Type.Int, 12, NewType.Byte),
-    HORSE_TYPE(Horse.class, 19, Type.Byte, 13, NewType.VarInt),
-    HORSE_SUBTYPE(Horse.class, 20, Type.Int, 14, NewType.VarInt),
-    HORSE_OWNER(Horse.class, 21, Type.String, 15, NewType.OptUUID),
-    HORSE_ARMOR(Horse.class, 22, Type.Int, 16, NewType.VarInt),
-    // bat
-    BAT_ISHANGING(Bat.class, 16, Type.Byte, 11, NewType.Byte),
-    // tameable
-    TAMING_INFO(Tameable.class, 16, Type.Byte, 12, NewType.Byte),
-    TAMING_OWNER(Tameable.class, 17, Type.String, 13, NewType.OptUUID),
-    // ocelot
-    OCELOT_TYPE(Ocelot.class, 18, Type.Byte, 14, NewType.VarInt),
-    // wolf
-    WOLF_HEALTH(Wolf.class, 18, Type.Float, 14, NewType.Float),
-    WOLF_BEGGING(Wolf.class, 19, Type.Byte, 15, NewType.Boolean),
-    WOLF_COLLAR(Wolf.class, 20, Type.Byte, 16, NewType.VarInt),
-    // pig
-    PIG_SADDLE(Pig.class, 16, Type.Byte, 12, NewType.Boolean),
-    // rabbit
-    RABBIT_TYPE(Rabbit.class, 18, Type.Byte, 12, NewType.VarInt),
-    // sheep
-    SHEEP_COLOR(Sheep.class, 16, Type.Byte, 12, NewType.Byte),
-    // villager
-    VILLAGER_PROFESSION(Villager.class, 16, Type.Int, 12, NewType.VarInt), // TODO write this to wiki.vg
-    // enderman
-    ENDERMAN_BLOCK(Enderman.class, 16, Type.Short, 11, NewType.BlockID), // special case
-    ENDERMAN_BLOCKDATA(Enderman.class, 17, Type.Byte, 11, NewType.BlockID), // special case
-    ENDERMAN_ISSCREAMING(Enderman.class, 18, Type.Byte, 12, NewType.Boolean),
-    // zombie
-    ZOMBIE_ISCHILD(Zombie.class, 12, Type.Byte, 11, NewType.Boolean),
-    ZOMBIE_ISVILLAGER(Zombie.class, 13, Type.Byte, 12, NewType.VarInt),
-    ZOMBIE_ISCONVERTING(Zombie.class, 14, Type.Byte, 13, NewType.Boolean),
-    // ZOMBIE_RISINGHANDS added in 1.9
-    // blaze
-    BLAZE_ONFIRE(Blaze.class, 16, Type.Byte, 11, NewType.Byte),
-    // spider
-    SPIDER_CIMBING(Spider.class, 16, Type.Byte, 11, NewType.Byte),
-    // creeper
-    CREEPER_FUSE(Creeper.class, 16, Type.Byte, 11, NewType.VarInt), // -1 idle, 1 is fuse
-    CREEPER_ISPOWERED(Creeper.class, 17, Type.Byte, 12, NewType.Boolean),
-    CREEPER_ISIGNITED(Creeper.class, 18, Type.Byte, 13, NewType.Boolean), // TODO: Write on wiki.vg for current prot
-    // ghast
-    GHAST_ISATTACKING(Ghast.class, 16, Type.Byte, 11, NewType.Boolean),
-    // slime
-    SLIME_SIZE(Slime.class, 16, Type.Byte, 11, NewType.VarInt),
-    // skeleton
-    SKELETON_TYPE(Skeleton.class, 13, Type.Byte, 11, NewType.VarInt),
-    // witch
-    WITCH_AGGRO(Witch.class, 21, Type.Byte, 11, NewType.Boolean),
-    // iron golem
-    IRON_PLAYERMADE(IronGolem.class, 16, Type.Byte, 11, NewType.Byte),
-    // wither
-    WITHER_TARGET1(Wither.class, 17, Type.Int, 11, NewType.VarInt),
-    WITHER_TARGET2(Wither.class, 18, Type.Int, 12, NewType.VarInt),
-    WITHER_TARGET3(Wither.class, 19, Type.Int, 13, NewType.VarInt),
-    WITHER_INVULN_TIME(Wither.class, 20, Type.Int, 14, NewType.VarInt),
-    // guardian
-    GUARDIAN_INFO(Guardian.class, 16, Type.Byte, 11, NewType.Byte),
-    GUARDIAN_TARGET(Guardian.class, 17, Type.Int, 12, NewType.VarInt),
-    // boat
-    BOAT_SINCEHIT(Boat.class, 17, Type.Int, 5, NewType.VarInt),
-    BOAT_FORWARDDIR(Boat.class, 18, Type.Int, 6, NewType.VarInt),
-    BOAT_DMGTAKEN(Boat.class, 19, Type.Float, 7, NewType.Float),
-    // BOAT_TYPE in 1.9
-    // minecart
-    MINECART_SHAKINGPOWER(Minecart.class, 17, Type.Int, 5, NewType.VarInt),
-    MINECART_SHAKINGDIRECTION(Minecart.class, 18, Type.Int, 6, NewType.VarInt),
-    MINECART_DAMAGETAKEN(Minecart.class, 19, Type.Float, 7, NewType.Float), // also shaking modifier :P
-    MINECART_BLOCK(Minecart.class, 20, Type.Int, 8, NewType.VarInt),
-    MINECART_BLOCK_Y(Minecart.class, 21, Type.Int, 9, NewType.VarInt),
-    MINECART_SHOWBLOCK(Minecart.class, 22, Type.Byte, 10, NewType.Boolean),
-    // furnace cart
-    FURNACECART_ISPOWERED(org.bukkit.entity.minecart.PoweredMinecart.class, 16, Type.Byte, 11, NewType.Boolean),
-    // item drop
-    ITEM_ITEM(Item.class, 10, Type.Slot, 5, NewType.Slot),
-    // arrow
-    ARROW_ISCRIT(Arrow.class, 16, Type.Byte, 5, NewType.Byte),
-    // firework
-    FIREWORK_INFO(Firework.class, 8, Type.Slot, 5, NewType.Slot),
-    // item frame
-    ITEMFRAME_ITEM(ItemFrame.class, 8, Type.Slot, 5, NewType.Slot),
-    ITEMFRAME_ROTATION(ItemFrame.class, 9, Type.Byte, 5, NewType.VarInt),
-    // ender crystal
-    ENDERCRYSTAL_HEALTH(EnderCrystal.class, 8, Type.Int, NewType.Discontinued),;
-
-    private Class<?> clazz;
-    private int newIndex;
-    private NewType newType;
-    private Type oldType;
-    private int index;
-
-    MetaIndex(Class<?> type, int index, Type oldType, NewType newType) {
-        this.clazz = type;
-        this.index = index;
-        this.newIndex = index;
-        this.oldType = oldType;
-        this.newType = newType;
-    }
-
-    MetaIndex(Class<?> type, int index, Type oldType, int newIndex, NewType newType) {
-        this.clazz = type;
-        this.index = index;
-        this.oldType = oldType;
-        this.newIndex = newIndex;
-        this.newType = newType;
-    }
-
-    public int getNewIndex() {
-        return newIndex;
-    }
-
-    public NewType getNewType() {
-        return newType;
-    }
-
-    public Type getOldType() {
-        return oldType;
-    }
-
-    public int getIndex() {
-        return index;
-    }
-
-    public Class<?> getApplicableClass() {
-        return this.clazz;
-    }
-
-    public static MetaIndex getIndex(Entity entity, int index) {
-        EntityType type;
-        if (entity instanceof Player) {
-            type = EntityType.PLAYER;
-        } else {
-            type = entity.getType();
-        }
-        return getIndex(type, index);
-    }
-
-    public static MetaIndex getIndex(EntityType type, int index) {
-        Class<? extends org.bukkit.entity.Entity> entityClass = type.getEntityClass();
-        if(entityClass == null){
-            System.out.println("Could not get entity class for " + type);
-            return null;
-        }
-        for (MetaIndex mi : MetaIndex.values()) {
-            if (mi.getIndex() == index) {
-                if (mi.getApplicableClass().isAssignableFrom(entityClass) ||
-                        mi.getApplicableClass().equals(entityClass)) {
-                    return mi;
-                }
-            }
-        }
-        // fall back to living entity
-        for (MetaIndex mi : MetaIndex.values()) {
-            if (mi.getIndex() == index) {
-                if (mi.getApplicableClass().isAssignableFrom(LivingEntity.class) ||
-                        mi.getApplicableClass().equals(LivingEntity.class)) {
-                    return mi;
-                }
-            }
-        }
-        return null;
-    }
-}
-
+package us.myles.ViaVersion.metadata;
+
+import lombok.Getter;
+import org.bukkit.entity.*;
+
+@Getter
+public enum MetaIndex {
+
+    // entity
+    ENTITY_STATUS(org.bukkit.entity.Entity.class, 0, Type.Byte, NewType.Byte),
+    ENTITY_AIR(org.bukkit.entity.Entity.class, 1, Type.Short, NewType.VarInt),
+    ENTITY_SILENT(org.bukkit.entity.Entity.class, 4, Type.Byte, NewType.Boolean),
+    // living entity
+    LIVINGENTITY_NAMETAG(LivingEntity.class, 2, Type.String, NewType.String),
+    LIVINGENTITY_ALWAYS_SHOW_NAMETAG(LivingEntity.class, 3, Type.Byte, NewType.Boolean),
+    LIVINGENTITY_HEALTH(LivingEntity.class, 6, Type.Float, NewType.Float),
+    LIVINGENTITY_POTION_EFFECT_COLOR(LivingEntity.class, 7, Type.Int, NewType.VarInt),
+    LIVINGENTITY_IS_POTION_AMBIENT(LivingEntity.class, 8, Type.Byte, NewType.Boolean),
+    LIVINGENTITY_NUMBER_OF_ARROWS_IN(LivingEntity.class, 9, Type.Byte, NewType.VarInt),
+    LIVINGENTITY_NO_AI(LivingEntity.class, 15, Type.Byte, 10, NewType.Byte), // in 1.9 this is combined with Left handed, oh.
+    // ageable
+    AGEABLE_AGE(Ageable.class, 12, Type.Byte, 11, NewType.Boolean),
+    // armour stand
+    STAND_INFO(ArmorStand.class, 10, Type.Byte, NewType.Byte),
+    STAND_HEAD_POS(ArmorStand.class, 11, Type.Rotation, NewType.Vector3F),
+    STAND_BODY_POS(ArmorStand.class, 12, Type.Rotation, NewType.Vector3F),
+    STAND_LA_POS(ArmorStand.class, 13, Type.Rotation, NewType.Vector3F),
+    STAND_RA_POS(ArmorStand.class, 14, Type.Rotation, NewType.Vector3F),
+    STAND_LL_POS(ArmorStand.class, 15, Type.Rotation, NewType.Vector3F),
+    STAND_RL_POS(ArmorStand.class, 16, Type.Rotation, NewType.Vector3F),
+    // human, discountined?
+    PLAYER_SKIN_FLAGS(HumanEntity.class, 10, Type.Byte, 12, NewType.Byte), // unsigned on 1.8
+    PLAYER_HUMAN_BYTE(HumanEntity.class, 16, Type.Byte, NewType.Discontinued), // unused on 1.8
+    PLAYER_ADDITIONAL_HEARTS(HumanEntity.class, 17, Type.Float, 10, NewType.Float),
+    PLAYER_SCORE(HumanEntity.class, 18, Type.Int, 11, NewType.VarInt),
+    PLAYER_HAND(HumanEntity.class, -1, Type.NonExistent, 5, NewType.Byte), // new in 1.9
+    // horse
+    HORSE_INFO(Horse.class, 16, Type.Int, 12, NewType.Byte),
+    HORSE_TYPE(Horse.class, 19, Type.Byte, 13, NewType.VarInt),
+    HORSE_SUBTYPE(Horse.class, 20, Type.Int, 14, NewType.VarInt),
+    HORSE_OWNER(Horse.class, 21, Type.String, 15, NewType.OptUUID),
+    HORSE_ARMOR(Horse.class, 22, Type.Int, 16, NewType.VarInt),
+    // bat
+    BAT_ISHANGING(Bat.class, 16, Type.Byte, 11, NewType.Byte),
+    // tameable
+    TAMING_INFO(Tameable.class, 16, Type.Byte, 12, NewType.Byte),
+    TAMING_OWNER(Tameable.class, 17, Type.String, 13, NewType.OptUUID),
+    // ocelot
+    OCELOT_TYPE(Ocelot.class, 18, Type.Byte, 14, NewType.VarInt),
+    // wolf
+    WOLF_HEALTH(Wolf.class, 18, Type.Float, 14, NewType.Float),
+    WOLF_BEGGING(Wolf.class, 19, Type.Byte, 15, NewType.Boolean),
+    WOLF_COLLAR(Wolf.class, 20, Type.Byte, 16, NewType.VarInt),
+    // pig
+    PIG_SADDLE(Pig.class, 16, Type.Byte, 12, NewType.Boolean),
+    // rabbit
+    RABBIT_TYPE(Rabbit.class, 18, Type.Byte, 12, NewType.VarInt),
+    // sheep
+    SHEEP_COLOR(Sheep.class, 16, Type.Byte, 12, NewType.Byte),
+    // villager
+    VILLAGER_PROFESSION(Villager.class, 16, Type.Int, 12, NewType.VarInt), // TODO write this to wiki.vg
+    // enderman
+    ENDERMAN_BLOCK(Enderman.class, 16, Type.Short, 11, NewType.BlockID), // special case
+    ENDERMAN_BLOCKDATA(Enderman.class, 17, Type.Byte, 11, NewType.BlockID), // special case
+    ENDERMAN_ISSCREAMING(Enderman.class, 18, Type.Byte, 12, NewType.Boolean),
+    // zombie
+    ZOMBIE_ISCHILD(Zombie.class, 12, Type.Byte, 11, NewType.Boolean),
+    ZOMBIE_ISVILLAGER(Zombie.class, 13, Type.Byte, 12, NewType.VarInt),
+    ZOMBIE_ISCONVERTING(Zombie.class, 14, Type.Byte, 13, NewType.Boolean),
+    // ZOMBIE_RISINGHANDS added in 1.9
+    // blaze
+    BLAZE_ONFIRE(Blaze.class, 16, Type.Byte, 11, NewType.Byte),
+    // spider
+    SPIDER_CIMBING(Spider.class, 16, Type.Byte, 11, NewType.Byte),
+    // creeper
+    CREEPER_FUSE(Creeper.class, 16, Type.Byte, 11, NewType.VarInt), // -1 idle, 1 is fuse
+    CREEPER_ISPOWERED(Creeper.class, 17, Type.Byte, 12, NewType.Boolean),
+    CREEPER_ISIGNITED(Creeper.class, 18, Type.Byte, 13, NewType.Boolean),
+    // ghast
+    GHAST_ISATTACKING(Ghast.class, 16, Type.Byte, 11, NewType.Boolean),
+    // slime
+    SLIME_SIZE(Slime.class, 16, Type.Byte, 11, NewType.VarInt),
+    // skeleton
+    SKELETON_TYPE(Skeleton.class, 13, Type.Byte, 11, NewType.VarInt),
+    // witch
+    WITCH_AGGRO(Witch.class, 21, Type.Byte, 11, NewType.Boolean),
+    // iron golem
+    IRON_PLAYERMADE(IronGolem.class, 16, Type.Byte, 11, NewType.Byte),
+    // wither
+    WITHER_TARGET1(Wither.class, 17, Type.Int, 11, NewType.VarInt),
+    WITHER_TARGET2(Wither.class, 18, Type.Int, 12, NewType.VarInt),
+    WITHER_TARGET3(Wither.class, 19, Type.Int, 13, NewType.VarInt),
+    WITHER_INVULN_TIME(Wither.class, 20, Type.Int, 14, NewType.VarInt),
+    WITHER_PROPERTIES(Wither.class, 10, Type.Byte, NewType.Byte),
+    WITHER_UNKNOWN(Wither.class, 11, Type.Byte, NewType.Discontinued),
+    // wither skull
+    WITHERSKULL_INVULN(WitherSkull.class, 10, Type.Byte, 5, NewType.Boolean),
+    // guardian
+    GUARDIAN_INFO(Guardian.class, 16, Type.Int, 11, NewType.Byte),
+    GUARDIAN_TARGET(Guardian.class, 17, Type.Int, 12, NewType.VarInt),
+    // boat
+    BOAT_SINCEHIT(Boat.class, 17, Type.Int, 5, NewType.VarInt),
+    BOAT_FORWARDDIR(Boat.class, 18, Type.Int, 6, NewType.VarInt),
+    BOAT_DMGTAKEN(Boat.class, 19, Type.Float, 7, NewType.Float),
+    // BOAT_TYPE in 1.9
+    // minecart
+    MINECART_SHAKINGPOWER(Minecart.class, 17, Type.Int, 5, NewType.VarInt),
+    MINECART_SHAKINGDIRECTION(Minecart.class, 18, Type.Int, 6, NewType.VarInt),
+    MINECART_DAMAGETAKEN(Minecart.class, 19, Type.Float, 7, NewType.Float), // also shaking modifier :P
+    MINECART_BLOCK(Minecart.class, 20, Type.Int, 8, NewType.VarInt),
+    MINECART_BLOCK_Y(Minecart.class, 21, Type.Int, 9, NewType.VarInt),
+    MINECART_SHOWBLOCK(Minecart.class, 22, Type.Byte, 10, NewType.Boolean),
+    // Command minecart (they are still broken)
+    MINECART_COMMANDBLOCK_COMMAND(Minecart.class, 23, Type.String, 11, NewType.String),
+    MINECART_COMMANDBLOCK_OUTPUT(Minecart.class, 24, Type.String, 12, NewType.Chat),
+    // furnace cart
+    FURNACECART_ISPOWERED(Minecart.class, 16, Type.Byte, 11, NewType.Boolean),
+    // item drop
+    ITEM_ITEM(Item.class, 10, Type.Slot, 5, NewType.Slot),
+    // arrow
+    ARROW_ISCRIT(Arrow.class, 16, Type.Byte, 5, NewType.Byte),
+    // firework
+    FIREWORK_INFO(Firework.class, 8, Type.Slot, 5, NewType.Slot),
+    // item frame
+    ITEMFRAME_ITEM(ItemFrame.class, 8, Type.Slot, 5, NewType.Slot),
+    ITEMFRAME_ROTATION(ItemFrame.class, 9, Type.Byte, 6, NewType.VarInt),
+    // ender crystal
+    ENDERCRYSTAL_HEALTH(EnderCrystal.class, 8, Type.Int, NewType.Discontinued),
+    // Ender dragon boss bar issues
+    ENDERDRAGON_UNKNOWN(EnderDragon.class, 5, Type.Byte, NewType.Discontinued),
+    ENDERDRAGON_NAME(EnderDragon.class, 10, Type.String, NewType.Discontinued),
+    // Normal Ender dragon
+    ENDERDRAGON_FLAG(EnderDragon.class, 15, Type.Byte, NewType.Discontinued),
+    ENDERDRAGON_PHASE(EnderDragon.class, 11, Type.Byte, NewType.VarInt);
+
+    private Class<?> clazz;
+    private int newIndex;
+    private NewType newType;
+    private Type oldType;
+    private int index;
+
+    MetaIndex(Class<?> type, int index, Type oldType, NewType newType) {
+        this.clazz = type;
+        this.index = index;
+        this.newIndex = index;
+        this.oldType = oldType;
+        this.newType = newType;
+    }
+
+    MetaIndex(Class<?> type, int index, Type oldType, int newIndex, NewType newType) {
+        this.clazz = type;
+        this.index = index;
+        this.oldType = oldType;
+        this.newIndex = newIndex;
+        this.newType = newType;
+    }
+
+    public static MetaIndex getIndex(EntityType type, int index) {
+        Class<? extends org.bukkit.entity.Entity> entityClass = type.getEntityClass();
+        if (entityClass == null) {
+            System.out.println("Could not get entity class for " + type);
+            return null;
+        }
+        for (MetaIndex mi : MetaIndex.values()) {
+            if (mi.getIndex() == index) {
+                // To fix issue with armour stands colliding with new values
+                if (mi.getApplicableClass().equals(LivingEntity.class)) continue;
+
+                if ((mi.getApplicableClass().isAssignableFrom(entityClass) ||
+                        mi.getApplicableClass().equals(entityClass))) {
+                    return mi;
+                }
+            }
+        }
+        // fall back to living entity
+        for (MetaIndex mi : MetaIndex.values()) {
+            if (mi.getIndex() == index) {
+                if (mi.getApplicableClass().isAssignableFrom(LivingEntity.class) ||
+                        mi.getApplicableClass().equals(LivingEntity.class)) {
+                    return mi;
+                }
+            }
+        }
+        return null;
+    }
+
+    public Class<?> getApplicableClass() {
+        return this.clazz;
+    }
+}
+

src/main/java/us/myles/ViaVersion/metadata/MetadataRewriter.java

@@ -0,0 +1,216 @@
+package us.myles.ViaVersion.metadata;
+
+import io.netty.buffer.ByteBuf;
+import lombok.Getter;
+import lombok.Setter;
+import org.bukkit.entity.EntityType;
+import org.bukkit.util.EulerAngle;
+import org.bukkit.util.Vector;
+import us.myles.ViaVersion.ViaVersionPlugin;
+import us.myles.ViaVersion.api.ViaVersion;
+import us.myles.ViaVersion.slot.ItemSlotRewriter;
+import us.myles.ViaVersion.slot.ItemSlotRewriter.ItemStack;
+import us.myles.ViaVersion.transformers.OutgoingTransformer;
+import us.myles.ViaVersion.util.PacketUtil;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+public class MetadataRewriter {
+
+    public static void writeMetadata1_9(EntityType type, List<Entry> list, ByteBuf output) {
+        short id = -1;
+        int data = -1;
+        for (Entry entry : list) {
+            MetaIndex metaIndex = entry.index;
+            try {
+                if (metaIndex.getNewType() != NewType.Discontinued) {
+                    if (metaIndex.getNewType() != NewType.BlockID || id != -1 && data == -1 || id == -1 && data != -1) { // block ID is only written if we have both parts
+                        output.writeByte(metaIndex.getNewIndex());
+                        output.writeByte(metaIndex.getNewType().getTypeID());
+                    }
+                    Object value = entry.value;
+                    switch (metaIndex.getNewType()) {
+                        case Byte:
+                            // convert from int, byte
+                            if (metaIndex.getOldType() == Type.Byte) {
+                                output.writeByte((Byte) value);
+                            }
+                            if (metaIndex.getOldType() == Type.Int) {
+                                output.writeByte(((Integer) value).byteValue());
+                            }
+                            // After writing the last one
+                            if (metaIndex == MetaIndex.ENTITY_STATUS && type == EntityType.PLAYER) {
+                                output.writeByte(MetaIndex.PLAYER_HAND.getNewIndex());
+                                output.writeByte(MetaIndex.PLAYER_HAND.getNewType().getTypeID());
+                                if ((((Byte) value) & 0x10) == 0x10) { // Player eating/aiming/drinking
+                                    output.writeByte(1); // Using main hand
+                                } else {
+                                    output.writeByte(0); // Not using any hand to stop animation
+                                }
+                            }
+                            break;
+                        case OptUUID:
+                            String owner = (String) value;
+                            UUID toWrite = null;
+                            if (owner.length() != 0) {
+                                try {
+                                    toWrite = UUID.fromString(owner);
+                                } catch (Exception ignored) {
+                                }
+                            }
+                            output.writeBoolean(toWrite != null);
+                            if (toWrite != null)
+                                PacketUtil.writeUUID(toWrite, output);
+                            break;
+                        case BlockID:
+                            // if we have both sources :))
+                            if (metaIndex.getOldType() == Type.Byte) {
+                                data = (Byte) value;
+                            }
+                            if (metaIndex.getOldType() == Type.Short) {
+                                id = (Short) value;
+                            }
+                            if (id != -1 && data != -1) {
+                                int combined = id << 4 | data;
+                                data = -1;
+                                id = -1;
+                                PacketUtil.writeVarInt(combined, output);
+                            }
+                            break;
+                        case VarInt:
+                            // convert from int, short, byte
+                            if (metaIndex.getOldType() == Type.Byte) {
+                                PacketUtil.writeVarInt(((Byte) value).intValue(), output);
+                            }
+                            if (metaIndex.getOldType() == Type.Short) {
+                                PacketUtil.writeVarInt(((Short) value).intValue(), output);
+                            }
+                            if (metaIndex.getOldType() == Type.Int) {
+                                PacketUtil.writeVarInt((Integer) value, output);
+                            }
+                            break;
+                        case Float:
+                            output.writeFloat((Float) value);
+                            break;
+                        case String:
+                            PacketUtil.writeString((String) value, output);
+                            break;
+                        case Boolean:
+                            if (metaIndex == MetaIndex.AGEABLE_AGE)
+                                output.writeBoolean((Byte) value < 0);
+                            else
+                                output.writeBoolean((Byte) value != 0);
+                            break;
+                        case Slot:
+                            ItemStack item = (ItemStack) value;
+                            ItemSlotRewriter.fixIdsFrom1_8To1_9(item);
+                            ItemSlotRewriter.writeItemStack(item, output);
+                            break;
+                        case Position:
+                            Vector vector = (Vector) value;
+                            output.writeInt((int) vector.getX());
+                            output.writeInt((int) vector.getY());
+                            output.writeInt((int) vector.getZ());
+                            break;
+                        case Vector3F:
+                            EulerAngle angle = (EulerAngle) value;
+                            output.writeFloat((float) angle.getX());
+                            output.writeFloat((float) angle.getY());
+                            output.writeFloat((float) angle.getZ());
+                            break;
+                        case Chat:
+                            PacketUtil.writeString(OutgoingTransformer.fixJson((String) value), output);
+                            break;
+                        default:
+                            System.out.println("[Out] Unhandled MetaDataType: " + metaIndex.getNewType());
+                            break;
+                    }
+                }
+            } catch (Exception e) {
+                if (!((ViaVersionPlugin) ViaVersion.getInstance()).isSuppressMetadataErrors()) {
+                    System.out.println("INCLUDE THIS IN YOUR ERROR LOG!");
+                    if (type != null)
+                        System.out.println("An error occurred with entity meta data for " + type + " OldID: " + entry.oldID);
+                    else
+                        System.out.println("An error occurred with entity meta data for UNKNOWN_ENTITY OldID: " + entry.oldID);
+                    if (metaIndex != null) {
+                        System.out.println("Old ID: " + metaIndex.getIndex() + " New ID: " + metaIndex.getNewIndex());
+                        System.out.println("Old Type: " + metaIndex.getOldType() + " New Type: " + metaIndex.getNewType());
+                    }
+                    e.printStackTrace();
+                }
+            }
+        }
+        output.writeByte(255);
+    }
+
+    public static List<Entry> readMetadata1_8(EntityType entityType, ByteBuf buf) {
+        List<Entry> entries = new ArrayList<>();
+        byte item;
+        while ((item = buf.readByte()) != 127) {
+            Type type = Type.byId((item & 0xE0) >> 5);
+            int id = item & 0x1F;
+            MetaIndex index = MetaIndex.getIndex(entityType, id);
+            switch (type) {
+                case Byte:
+                    entries.add(new Entry(index, buf.readByte(), id));
+                    break;
+                case Short:
+                    entries.add(new Entry(index, buf.readShort(), id));
+                    break;
+                case Int:
+                    entries.add(new Entry(index, buf.readInt(), id));
+                    break;
+                case Float:
+                    entries.add(new Entry(index, buf.readFloat(), id));
+                    break;
+                case String:
+                    entries.add(new Entry(index, PacketUtil.readString(buf), id));
+                    break;
+                case Slot: {
+                    try {
+                        entries.add(new Entry(index, ItemSlotRewriter.readItemStack(buf), id));
+                    } catch (Exception e) {
+                        e.printStackTrace();
+                    }
+                }
+                break;
+                case Position: {
+                    int x = buf.readInt();
+                    int y = buf.readInt();
+                    int z = buf.readInt();
+                    entries.add(new Entry(index, new Vector(x, y, z), id));
+                    break;
+                }
+                case Rotation: {
+                    float x = buf.readFloat();
+                    float y = buf.readFloat();
+                    float z = buf.readFloat();
+                    entries.add(new Entry(index, new EulerAngle(x, y, z), id));
+                    break;
+                }
+                default:
+                    System.out.println("[Out] Unhandled MetaDataType: " + type);
+                    break;
+            }
+        }
+        return entries;
+    }
+
+    @Getter
+    @Setter
+    public static final class Entry {
+
+        private final int oldID;
+        private MetaIndex index;
+        private Object value;
+
+        public Entry(MetaIndex index, Object value, int id) {
+            this.index = index;
+            this.value = value;
+            this.oldID = id;
+        }
+    }
+}

src/main/java/us/myles/ViaVersion/metadata/NewType.java

@@ -1,5 +1,10 @@
 package us.myles.ViaVersion.metadata;
 
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+@Getter
 public enum NewType {
     Byte(0),
     VarInt(1),
@@ -15,13 +20,7 @@ public enum NewType {
     OptUUID(11),
     BlockID(12),
     Discontinued(99);
+
     private final int typeID;
 
-    NewType(int typeID){
-        this.typeID = typeID;
-    }
-
-    public int getTypeID() {
-        return typeID;
-    }
 }

src/main/java/us/myles/ViaVersion/metadata/Type.java

@@ -1,5 +1,10 @@
 package us.myles.ViaVersion.metadata;
 
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+@Getter
 public enum Type {
     Byte(0),
     Short(1),
@@ -8,14 +13,11 @@ public enum Type {
     String(4),
     Slot(5),
     Position(6),
-    Rotation(7);
+    Rotation(7),
+    NonExistent(-1);
     private final int typeID;
 
-    Type(int typeID){
-        this.typeID = typeID;
-    }
-
-    public int getTypeID() {
-        return typeID;
+    public static Type byId(int id) {
+        return values()[id];
     }
 }

src/main/java/us/myles/ViaVersion/packets/PacketType.java

@@ -1,196 +1,203 @@
-package us.myles.ViaVersion.packets;
-
-public enum PacketType {
-    /* Handshake serverbound */
-    HANDSHAKE(State.HANDSHAKE, Direction.INCOMING, 0x00),
-    /* Login serverbound */
-    LOGIN_START(State.LOGIN, Direction.INCOMING, 0x00),
-    LOGIN_ENCRYPTION_RESPONSE(State.LOGIN, Direction.INCOMING, 0x01),
-    /* Login clientbound */
-    LOGIN_DISCONNECT(State.LOGIN, Direction.OUTGOING, 0x00),
-    LOGIN_ENCRYPTION_REQUEST(State.LOGIN, Direction.OUTGOING, 0x01),
-    LOGIN_SUCCESS(State.LOGIN, Direction.OUTGOING, 0x02),
-    LOGIN_SETCOMPRESSION(State.LOGIN, Direction.OUTGOING, 0x03),
-    /* Status serverbound */
-    STATUS_REQUEST(State.STATUS, Direction.INCOMING, 0x00),
-    STATUS_PING(State.STATUS, Direction.INCOMING, 0x01),
-    /* Status clientbound */
-    STATUS_RESPONSE(State.STATUS, Direction.OUTGOING, 0x00),
-    STATUS_PONG(State.STATUS, Direction.OUTGOING, 0x01),
-    /* Play serverbound */
-    PLAY_TP_CONFIRM(State.PLAY, Direction.INCOMING, -1, 0x00),
-    PLAY_TAB_COMPLETE_REQUEST(State.PLAY, Direction.INCOMING, 0x14, 0x01),
-    PLAY_CLICHAT_MESSAGE_CLIENT(State.PLAY, Direction.INCOMING, 0x01, 0x02),
-    PLAY_CLIENT_STATUS(State.PLAY, Direction.INCOMING, 0x16, 0x03),
-    PLAY_CLIENT_SETTINGS(State.PLAY, Direction.INCOMING, 0x15, 0x04),
-    PLAY_CONFIRM_TRANS(State.PLAY, Direction.INCOMING, 0x0F, 0x05),
-    PLAY_ENCHANT_ITEM(State.PLAY, Direction.INCOMING, 0x11, 0x06),
-    PLAY_CLICK_WINDOW(State.PLAY, Direction.INCOMING, 0x0E, 0x07),
-    PLAY_CLOSE_WINDOW_REQUEST(State.PLAY, Direction.INCOMING, 0x0D, 0x08),
-    PLAY_PLUGIN_MESSAGE_REQUEST(State.PLAY, Direction.INCOMING, 0x17, 0x09),
-    PLAY_USE_ENTITY(State.PLAY, Direction.INCOMING, 0x02, 0x0A),
-    PLAY_KEEP_ALIVE_REQUEST(State.PLAY, Direction.INCOMING, 0x00, 0x0B),
-    PLAY_PLAYER_POSITION_REQUEST(State.PLAY, Direction.INCOMING, 0x04, 0x0C),
-    PLAY_PLAYER_POSITION_LOOK_REQUEST(State.PLAY, Direction.INCOMING, 0x06, 0x0D),
-    PLAY_PLAYER_LOOK_REQUEST(State.PLAY, Direction.INCOMING, 0x05, 0x0E),
-    PLAY_PLAYER(State.PLAY, Direction.INCOMING, 0x03, 0x0F),
-    PLAY_VEHICLE_MOVE_REQUEST(State.PLAY, Direction.INCOMING, -1, 0x10),
-    PLAY_STEER_BOAT(State.PLAY, Direction.INCOMING, -1, 0x11),
-    PLAY_PLAYER_ABILITIES_REQUEST(State.PLAY, Direction.INCOMING, 0x13, 0x12),
-    PLAY_PLAYER_DIGGING(State.PLAY, Direction.INCOMING, 0x07, 0x13),
-    PLAY_ENTITY_ACTION(State.PLAY, Direction.INCOMING, 0x0B, 0x14),
-    PLAY_STEER_VEHICLE(State.PLAY, Direction.INCOMING, 0x0C, 0x15),
-    PLAY_RESOURCE_PACK_STATUS(State.PLAY, Direction.INCOMING, 0x19, 0x16),
-    PLAY_HELD_ITEM_CHANGE_REQUEST(State.PLAY, Direction.INCOMING, 0x09, 0x17),
-    PLAY_CREATIVE_INVENTORY_ACTION(State.PLAY, Direction.INCOMING, 0x10, 0x18),
-    PLAY_UPDATE_SIGN_REQUEST(State.PLAY, Direction.INCOMING, 0x12, 0x19),
-    PLAY_ANIMATION_REQUEST(State.PLAY, Direction.INCOMING, 0x0A, 0x1A),
-    PLAY_SPECTATE(State.PLAY, Direction.INCOMING, 0x18, 0x1B),
-    PLAY_PLAYER_BLOCK_PLACEMENT(State.PLAY, Direction.INCOMING, 0x08, 0x1C),
-    PLAY_USE_ITEM(State.PLAY, Direction.INCOMING, -1, 0x1D),
-    /* Play clientbound */
-    PLAY_SPAWN_OBJECT(State.PLAY, Direction.OUTGOING, 0x0E, 0x00),
-    PLAY_SPAWN_XP_ORB(State.PLAY, Direction.OUTGOING, 0x11, 0x01),
-    PLAY_SPAWN_GLOBAL_ENTITY(State.PLAY, Direction.OUTGOING, 0x2C, 0x02),
-    PLAY_SPAWN_MOB(State.PLAY, Direction.OUTGOING, 0x0F, 0x03),
-    PLAY_SPAWN_PAINTING(State.PLAY, Direction.OUTGOING, 0x10, 0x04),
-    PLAY_SPAWN_PLAYER(State.PLAY, Direction.OUTGOING, 0x0C, 0x05),
-    PLAY_ANIMATION(State.PLAY, Direction.OUTGOING, 0x0B, 0x06),
-    PLAY_STATS(State.PLAY, Direction.OUTGOING, 0x37, 0x07),
-    PLAY_BLOCK_BREAK_ANIMATION(State.PLAY, Direction.OUTGOING, 0x25, 0x08),
-    PLAY_UPDATE_BLOCK_ENTITY(State.PLAY, Direction.OUTGOING, 0x35, 0x09),
-    PLAY_BLOCK_ACTION(State.PLAY, Direction.OUTGOING, 0x24, 0x0A),
-    PLAY_BLOCK_CHANGE(State.PLAY, Direction.OUTGOING, 0x23, 0x0B),
-    PLAY_BOSS_BAR(State.PLAY, Direction.OUTGOING, -1, 0x0C),
-    PLAY_SERVER_DIFFICULTY(State.PLAY, Direction.OUTGOING, 0x41, 0x0D),
-    PLAY_TAB_COMPLETE(State.PLAY, Direction.OUTGOING, 0x3A, 0x0E),
-    PLAY_CHAT_MESSAGE(State.PLAY, Direction.OUTGOING, 0x02, 0x0F),
-    PLAY_MULTI_BLOCK_CHANGE(State.PLAY, Direction.OUTGOING, 0x22, 0x10),
-    PLAY_CONFIRM_TRANSACTION(State.PLAY, Direction.OUTGOING, 0x32, 0x11),
-    PLAY_CLOSE_WINDOW(State.PLAY, Direction.OUTGOING, 0x2E, 0x12),
-    PLAY_OPEN_WINDOW(State.PLAY, Direction.OUTGOING, 0x2D, 0x13),
-    PLAY_WINDOW_ITEMS(State.PLAY, Direction.OUTGOING, 0x30, 0x14),
-    PLAY_WINDOW_PROPERTY(State.PLAY, Direction.OUTGOING, 0x31, 0x15),
-    PLAY_SET_SLOT(State.PLAY, Direction.OUTGOING, 0x2F, 0x16),
-    PLAY_SET_COOLDOWN(State.PLAY, Direction.OUTGOING, -1, 0x17),
-    PLAY_PLUGIN_MESSAGE(State.PLAY, Direction.OUTGOING, 0x3F, 0x18),
-    PLAY_NAMED_SOUND_EFFECT(State.PLAY, Direction.OUTGOING, 0x29, 0x19),
-    PLAY_DISCONNECT(State.PLAY, Direction.OUTGOING, 0x40, 0x1A),
-    PLAY_ENTITY_STATUS(State.PLAY, Direction.OUTGOING, 0x1A, 0x1B),
-    PLAY_EXPLOSION(State.PLAY, Direction.OUTGOING, 0x27, 0x1C),
-    PLAY_UNLOAD_CHUNK(State.PLAY, Direction.OUTGOING, -1, 0x1D),
-    PLAY_CHANGE_GAME_STATE(State.PLAY, Direction.OUTGOING, 0x2B, 0x1E),
-    PLAY_KEEP_ALIVE(State.PLAY, Direction.OUTGOING, 0x00, 0x1F),
-    PLAY_CHUNK_DATA(State.PLAY, Direction.OUTGOING, 0x21, 0x20),
-    PLAY_EFFECT(State.PLAY, Direction.OUTGOING, 0x28, 0x21),
-    PLAY_PARTICLE(State.PLAY, Direction.OUTGOING, 0x2A, 0x22),
-    PLAY_JOIN_GAME(State.PLAY, Direction.OUTGOING, 0x01, 0x23),
-    PLAY_MAP(State.PLAY, Direction.OUTGOING, 0x34, 0x24),
-    PLAY_ENTITY_RELATIVE_MOVE(State.PLAY, Direction.OUTGOING, 0x15, 0x25),
-    PLAY_ENTITY_LOOK_MOVE(State.PLAY, Direction.OUTGOING, 0x17, 0x26),
-    PLAY_ENTITY_LOOK(State.PLAY, Direction.OUTGOING, 0x16, 0x27),
-    PLAY_ENTITY(State.PLAY, Direction.OUTGOING, 0x14, 0x28),
-    PLAY_VEHICLE_MOVE(State.PLAY, Direction.OUTGOING, -1, 0x29),
-    PLAY_OPEN_SIGN_EDITOR(State.PLAY, Direction.OUTGOING, 0x36, 0x2A),
-    PLAY_PLAYER_ABILITIES(State.PLAY, Direction.OUTGOING, 0x39, 0x2B),
-    PLAY_COMBAT_EVENT(State.PLAY, Direction.OUTGOING, 0x42, 0x2C),
-    PLAY_PLAYER_LIST_ITEM(State.PLAY, Direction.OUTGOING, 0x38, 0x2D),
-    PLAY_PLAYER_POSITION_LOOK(State.PLAY, Direction.OUTGOING, 0x08, 0x2E),
-    PLAY_USE_BED(State.PLAY, Direction.OUTGOING, 0x2F, 0x2F),
-    PLAY_DESTROY_ENTITIES(State.PLAY, Direction.OUTGOING, 0x13, 0x30),
-    PLAY_REMOVE_ENTITY_EFFECT(State.PLAY, Direction.OUTGOING, 0x1E, 0x31),
-    PLAY_RESOURCE_PACK_SEND(State.PLAY, Direction.OUTGOING, 0x48, 0x32),
-    PLAY_RESPAWN(State.PLAY, Direction.OUTGOING, 0x07, 0x33),
-    PLAY_ENTITY_HEAD_LOOK(State.PLAY, Direction.OUTGOING, 0x19, 0x34),
-    PLAY_WORLD_BORDER(State.PLAY, Direction.OUTGOING, 0x44, 0x35),
-    PLAY_CAMERA(State.PLAY, Direction.OUTGOING, 0x43, 0x36),
-    PLAY_HELD_ITEM_CHANGE(State.PLAY, Direction.OUTGOING, 0x09, 0x37),
-    PLAY_DISPLAY_SCOREBOARD(State.PLAY, Direction.OUTGOING, 0x3D, 0x38),
-    PLAY_ENTITY_METADATA(State.PLAY, Direction.OUTGOING, 0x1C, 0x39),
-    PLAY_ATTACH_ENTITY(State.PLAY, Direction.OUTGOING, 0x1B, 0x3A),
-    PLAY_ENTITY_VELOCITY(State.PLAY, Direction.OUTGOING, 0x12, 0x3B),
-    PLAY_ENTITY_EQUIPMENT(State.PLAY, Direction.OUTGOING, 0x04, 0x3C),
-    PLAY_SET_XP(State.PLAY, Direction.OUTGOING, 0x1F, 0x3D),
-    PLAY_UPDATE_HEALTH(State.PLAY, Direction.OUTGOING, 0x06, 0x3E),
-    PLAY_SCOREBOARD_OBJ(State.PLAY, Direction.OUTGOING, 0x3B, 0x3F),
-    PLAY_SET_PASSENGERS(State.PLAY, Direction.OUTGOING, -1, 0x40),
-    PLAY_TEAM(State.PLAY, Direction.OUTGOING, 0x3E, 0x41),
-    PLAY_UPDATE_SCORE(State.PLAY, Direction.OUTGOING, 0x3C, 0x42),
-    PLAY_SPAWN_POSITION(State.PLAY, Direction.OUTGOING, 0x05, 0x43),
-    PLAY_TIME_UPDATE(State.PLAY, Direction.OUTGOING, 0x03, 0x44),
-    PLAY_TITLE(State.PLAY, Direction.OUTGOING, 0x45, 0x45),
-    PLAY_UPDATE_SIGN(State.PLAY, Direction.OUTGOING, 0x33, 0x46),
-    PLAY_SOUND_EFFECT(State.PLAY, Direction.OUTGOING, -1, 0x47),
-    PLAY_PLAYER_LIST_HEADER_FOOTER(State.PLAY, Direction.OUTGOING, 0x47, 0x48),
-    PLAY_COLLECT_ITEM(State.PLAY, Direction.OUTGOING, 0x0D, 0x49),
-    PLAY_ENTITY_TELEPORT(State.PLAY, Direction.OUTGOING, 0x18, 0x4A),
-    PLAY_ENTITY_PROPERTIES(State.PLAY, Direction.OUTGOING, 0x20, 0x4B),
-    PLAY_ENTITY_EFFECT(State.PLAY, Direction.OUTGOING, 0x1D, 0x4C),
-
-    PLAY_MAP_CHUNK_BULK(State.PLAY, Direction.OUTGOING, 0x26, -1),
-    PLAY_SET_COMPRESSION(State.PLAY, Direction.OUTGOING, 0x46, -1),
-    PLAY_UPDATE_ENTITY_NBT(State.PLAY, Direction.OUTGOING, 0x49, -1),;
-
-    private State state;
-    private Direction direction;
-    private int packetID;
-    private int newPacketID = -1;
-
-    PacketType(State state, Direction direction, int packetID) {
-        this.state = state;
-        this.direction = direction;
-        this.packetID = packetID;
-        this.newPacketID = packetID;
-    }
-
-    PacketType(State state, Direction direction, int packetID, int newPacketID) {
-        this.state = state;
-        this.direction = direction;
-        this.packetID = packetID;
-        this.newPacketID = newPacketID;
-    }
-
-    public State getState() {
-        return state;
-    }
-
-    public Direction getDirection() {
-        return direction;
-    }
-
-    public int getPacketID() {
-        return packetID;
-    }
-
-    public int getNewPacketID() {
-        return newPacketID;
-    }
-
-    public static PacketType findNewPacket(State state, Direction direction, int id) {
-        for (PacketType pt : values()) {
-            if (pt.getNewPacketID() == id && id != -1
-                    && pt.getState() == state
-                    && pt.getDirection() == direction)
-                return pt;
-        }
-        return null;
-    }
-
-    public static PacketType findOldPacket(State state, Direction direction, int id) {
-        for (PacketType pt : values()) {
-            if (pt.getPacketID() == id && id != -1
-                    && pt.getState() == state
-                    && pt.getDirection() == direction)
-                return pt;
-        }
-        return null;
-    }
-
-    public static PacketType getIncomingPacket(State state, int id) {
-        return findNewPacket(state, Direction.INCOMING, id);
-    }
-
-    public static PacketType getOutgoingPacket(State state, int id) {
-        return findOldPacket(state, Direction.OUTGOING, id);
-    }
-}
+package us.myles.ViaVersion.packets;
+
+import java.util.HashMap;
+
+import com.google.common.collect.HashBasedTable;
+import com.google.common.collect.Table;
+
+public enum PacketType {
+    /* Handshake serverbound */
+    HANDSHAKE(State.HANDSHAKE, Direction.INCOMING, 0x00),
+    /* Login serverbound */
+    LOGIN_START(State.LOGIN, Direction.INCOMING, 0x00),
+    LOGIN_ENCRYPTION_RESPONSE(State.LOGIN, Direction.INCOMING, 0x01),
+    /* Login clientbound */
+    LOGIN_DISCONNECT(State.LOGIN, Direction.OUTGOING, 0x00),
+    LOGIN_ENCRYPTION_REQUEST(State.LOGIN, Direction.OUTGOING, 0x01),
+    LOGIN_SUCCESS(State.LOGIN, Direction.OUTGOING, 0x02),
+    LOGIN_SETCOMPRESSION(State.LOGIN, Direction.OUTGOING, 0x03),
+    /* Status serverbound */
+    STATUS_REQUEST(State.STATUS, Direction.INCOMING, 0x00),
+    STATUS_PING(State.STATUS, Direction.INCOMING, 0x01),
+    /* Status clientbound */
+    STATUS_RESPONSE(State.STATUS, Direction.OUTGOING, 0x00),
+    STATUS_PONG(State.STATUS, Direction.OUTGOING, 0x01),
+    /* Play serverbound */
+    PLAY_TP_CONFIRM(State.PLAY, Direction.INCOMING, -1, 0x00),
+    PLAY_TAB_COMPLETE_REQUEST(State.PLAY, Direction.INCOMING, 0x14, 0x01),
+    PLAY_CHAT_MESSAGE_CLIENT(State.PLAY, Direction.INCOMING, 0x01, 0x02),
+    PLAY_CLIENT_STATUS(State.PLAY, Direction.INCOMING, 0x16, 0x03),
+    PLAY_CLIENT_SETTINGS(State.PLAY, Direction.INCOMING, 0x15, 0x04),
+    PLAY_CONFIRM_TRANS(State.PLAY, Direction.INCOMING, 0x0F, 0x05),
+    PLAY_ENCHANT_ITEM(State.PLAY, Direction.INCOMING, 0x11, 0x06),
+    PLAY_CLICK_WINDOW(State.PLAY, Direction.INCOMING, 0x0E, 0x07),
+    PLAY_CLOSE_WINDOW_REQUEST(State.PLAY, Direction.INCOMING, 0x0D, 0x08),
+    PLAY_PLUGIN_MESSAGE_REQUEST(State.PLAY, Direction.INCOMING, 0x17, 0x09),
+    PLAY_USE_ENTITY(State.PLAY, Direction.INCOMING, 0x02, 0x0A),
+    PLAY_KEEP_ALIVE_REQUEST(State.PLAY, Direction.INCOMING, 0x00, 0x0B),
+    PLAY_PLAYER_POSITION_REQUEST(State.PLAY, Direction.INCOMING, 0x04, 0x0C),
+    PLAY_PLAYER_POSITION_LOOK_REQUEST(State.PLAY, Direction.INCOMING, 0x06, 0x0D),
+    PLAY_PLAYER_LOOK_REQUEST(State.PLAY, Direction.INCOMING, 0x05, 0x0E),
+    PLAY_PLAYER(State.PLAY, Direction.INCOMING, 0x03, 0x0F),
+    PLAY_VEHICLE_MOVE_REQUEST(State.PLAY, Direction.INCOMING, -1, 0x10),
+    PLAY_STEER_BOAT(State.PLAY, Direction.INCOMING, -1, 0x11),
+    PLAY_PLAYER_ABILITIES_REQUEST(State.PLAY, Direction.INCOMING, 0x13, 0x12),
+    PLAY_PLAYER_DIGGING(State.PLAY, Direction.INCOMING, 0x07, 0x13),
+    PLAY_ENTITY_ACTION(State.PLAY, Direction.INCOMING, 0x0B, 0x14),
+    PLAY_STEER_VEHICLE(State.PLAY, Direction.INCOMING, 0x0C, 0x15),
+    PLAY_RESOURCE_PACK_STATUS(State.PLAY, Direction.INCOMING, 0x19, 0x16),
+    PLAY_HELD_ITEM_CHANGE_REQUEST(State.PLAY, Direction.INCOMING, 0x09, 0x17),
+    PLAY_CREATIVE_INVENTORY_ACTION(State.PLAY, Direction.INCOMING, 0x10, 0x18),
+    PLAY_UPDATE_SIGN_REQUEST(State.PLAY, Direction.INCOMING, 0x12, 0x19),
+    PLAY_ANIMATION_REQUEST(State.PLAY, Direction.INCOMING, 0x0A, 0x1A),
+    PLAY_SPECTATE(State.PLAY, Direction.INCOMING, 0x18, 0x1B),
+    PLAY_PLAYER_BLOCK_PLACEMENT(State.PLAY, Direction.INCOMING, 0x08, 0x1C),
+    PLAY_USE_ITEM(State.PLAY, Direction.INCOMING, -1, 0x1D),
+    /* Play clientbound */
+    PLAY_SPAWN_OBJECT(State.PLAY, Direction.OUTGOING, 0x0E, 0x00),
+    PLAY_SPAWN_XP_ORB(State.PLAY, Direction.OUTGOING, 0x11, 0x01),
+    PLAY_SPAWN_GLOBAL_ENTITY(State.PLAY, Direction.OUTGOING, 0x2C, 0x02),
+    PLAY_SPAWN_MOB(State.PLAY, Direction.OUTGOING, 0x0F, 0x03),
+    PLAY_SPAWN_PAINTING(State.PLAY, Direction.OUTGOING, 0x10, 0x04),
+    PLAY_SPAWN_PLAYER(State.PLAY, Direction.OUTGOING, 0x0C, 0x05),
+    PLAY_ANIMATION(State.PLAY, Direction.OUTGOING, 0x0B, 0x06),
+    PLAY_STATS(State.PLAY, Direction.OUTGOING, 0x37, 0x07),
+    PLAY_BLOCK_BREAK_ANIMATION(State.PLAY, Direction.OUTGOING, 0x25, 0x08),
+    PLAY_UPDATE_BLOCK_ENTITY(State.PLAY, Direction.OUTGOING, 0x35, 0x09),
+    PLAY_BLOCK_ACTION(State.PLAY, Direction.OUTGOING, 0x24, 0x0A),
+    PLAY_BLOCK_CHANGE(State.PLAY, Direction.OUTGOING, 0x23, 0x0B),
+    PLAY_BOSS_BAR(State.PLAY, Direction.OUTGOING, -1, 0x0C),
+    PLAY_SERVER_DIFFICULTY(State.PLAY, Direction.OUTGOING, 0x41, 0x0D),
+    PLAY_TAB_COMPLETE(State.PLAY, Direction.OUTGOING, 0x3A, 0x0E),
+    PLAY_CHAT_MESSAGE(State.PLAY, Direction.OUTGOING, 0x02, 0x0F),
+    PLAY_MULTI_BLOCK_CHANGE(State.PLAY, Direction.OUTGOING, 0x22, 0x10),
+    PLAY_CONFIRM_TRANSACTION(State.PLAY, Direction.OUTGOING, 0x32, 0x11),
+    PLAY_CLOSE_WINDOW(State.PLAY, Direction.OUTGOING, 0x2E, 0x12),
+    PLAY_OPEN_WINDOW(State.PLAY, Direction.OUTGOING, 0x2D, 0x13),
+    PLAY_WINDOW_ITEMS(State.PLAY, Direction.OUTGOING, 0x30, 0x14),
+    PLAY_WINDOW_PROPERTY(State.PLAY, Direction.OUTGOING, 0x31, 0x15),
+    PLAY_SET_SLOT(State.PLAY, Direction.OUTGOING, 0x2F, 0x16),
+    PLAY_SET_COOLDOWN(State.PLAY, Direction.OUTGOING, -1, 0x17),
+    PLAY_PLUGIN_MESSAGE(State.PLAY, Direction.OUTGOING, 0x3F, 0x18),
+    PLAY_NAMED_SOUND_EFFECT(State.PLAY, Direction.OUTGOING, 0x29, 0x19),
+    PLAY_DISCONNECT(State.PLAY, Direction.OUTGOING, 0x40, 0x1A),
+    PLAY_ENTITY_STATUS(State.PLAY, Direction.OUTGOING, 0x1A, 0x1B),
+    PLAY_EXPLOSION(State.PLAY, Direction.OUTGOING, 0x27, 0x1C),
+    PLAY_UNLOAD_CHUNK(State.PLAY, Direction.OUTGOING, -1, 0x1D),
+    PLAY_CHANGE_GAME_STATE(State.PLAY, Direction.OUTGOING, 0x2B, 0x1E),
+    PLAY_KEEP_ALIVE(State.PLAY, Direction.OUTGOING, 0x00, 0x1F),
+    PLAY_CHUNK_DATA(State.PLAY, Direction.OUTGOING, 0x21, 0x20),
+    PLAY_EFFECT(State.PLAY, Direction.OUTGOING, 0x28, 0x21),
+    PLAY_PARTICLE(State.PLAY, Direction.OUTGOING, 0x2A, 0x22),
+    PLAY_JOIN_GAME(State.PLAY, Direction.OUTGOING, 0x01, 0x23),
+    PLAY_MAP(State.PLAY, Direction.OUTGOING, 0x34, 0x24),
+    PLAY_ENTITY_RELATIVE_MOVE(State.PLAY, Direction.OUTGOING, 0x15, 0x25),
+    PLAY_ENTITY_LOOK_MOVE(State.PLAY, Direction.OUTGOING, 0x17, 0x26),
+    PLAY_ENTITY_LOOK(State.PLAY, Direction.OUTGOING, 0x16, 0x27),
+    PLAY_ENTITY(State.PLAY, Direction.OUTGOING, 0x14, 0x28),
+    PLAY_VEHICLE_MOVE(State.PLAY, Direction.OUTGOING, -1, 0x29),
+    PLAY_OPEN_SIGN_EDITOR(State.PLAY, Direction.OUTGOING, 0x36, 0x2A),
+    PLAY_PLAYER_ABILITIES(State.PLAY, Direction.OUTGOING, 0x39, 0x2B),
+    PLAY_COMBAT_EVENT(State.PLAY, Direction.OUTGOING, 0x42, 0x2C),
+    PLAY_PLAYER_LIST_ITEM(State.PLAY, Direction.OUTGOING, 0x38, 0x2D),
+    PLAY_PLAYER_POSITION_LOOK(State.PLAY, Direction.OUTGOING, 0x08, 0x2E),
+    PLAY_USE_BED(State.PLAY, Direction.OUTGOING, 0x0A, 0x2F),
+    PLAY_DESTROY_ENTITIES(State.PLAY, Direction.OUTGOING, 0x13, 0x30),
+    PLAY_REMOVE_ENTITY_EFFECT(State.PLAY, Direction.OUTGOING, 0x1E, 0x31),
+    PLAY_RESOURCE_PACK_SEND(State.PLAY, Direction.OUTGOING, 0x48, 0x32),
+    PLAY_RESPAWN(State.PLAY, Direction.OUTGOING, 0x07, 0x33),
+    PLAY_ENTITY_HEAD_LOOK(State.PLAY, Direction.OUTGOING, 0x19, 0x34),
+    PLAY_WORLD_BORDER(State.PLAY, Direction.OUTGOING, 0x44, 0x35),
+    PLAY_CAMERA(State.PLAY, Direction.OUTGOING, 0x43, 0x36),
+    PLAY_HELD_ITEM_CHANGE(State.PLAY, Direction.OUTGOING, 0x09, 0x37),
+    PLAY_DISPLAY_SCOREBOARD(State.PLAY, Direction.OUTGOING, 0x3D, 0x38),
+    PLAY_ENTITY_METADATA(State.PLAY, Direction.OUTGOING, 0x1C, 0x39),
+    PLAY_ATTACH_ENTITY(State.PLAY, Direction.OUTGOING, 0x1B, 0x3A),
+    PLAY_ENTITY_VELOCITY(State.PLAY, Direction.OUTGOING, 0x12, 0x3B),
+    PLAY_ENTITY_EQUIPMENT(State.PLAY, Direction.OUTGOING, 0x04, 0x3C),
+    PLAY_SET_XP(State.PLAY, Direction.OUTGOING, 0x1F, 0x3D),
+    PLAY_UPDATE_HEALTH(State.PLAY, Direction.OUTGOING, 0x06, 0x3E),
+    PLAY_SCOREBOARD_OBJ(State.PLAY, Direction.OUTGOING, 0x3B, 0x3F),
+    PLAY_SET_PASSENGERS(State.PLAY, Direction.OUTGOING, -1, 0x40),
+    PLAY_TEAM(State.PLAY, Direction.OUTGOING, 0x3E, 0x41),
+    PLAY_UPDATE_SCORE(State.PLAY, Direction.OUTGOING, 0x3C, 0x42),
+    PLAY_SPAWN_POSITION(State.PLAY, Direction.OUTGOING, 0x05, 0x43),
+    PLAY_TIME_UPDATE(State.PLAY, Direction.OUTGOING, 0x03, 0x44),
+    PLAY_TITLE(State.PLAY, Direction.OUTGOING, 0x45, 0x45),
+    PLAY_UPDATE_SIGN(State.PLAY, Direction.OUTGOING, 0x33, 0x46),
+    PLAY_SOUND_EFFECT(State.PLAY, Direction.OUTGOING, -1, 0x47),
+    PLAY_PLAYER_LIST_HEADER_FOOTER(State.PLAY, Direction.OUTGOING, 0x47, 0x48),
+    PLAY_COLLECT_ITEM(State.PLAY, Direction.OUTGOING, 0x0D, 0x49),
+    PLAY_ENTITY_TELEPORT(State.PLAY, Direction.OUTGOING, 0x18, 0x4A),
+    PLAY_ENTITY_PROPERTIES(State.PLAY, Direction.OUTGOING, 0x20, 0x4B),
+    PLAY_ENTITY_EFFECT(State.PLAY, Direction.OUTGOING, 0x1D, 0x4C),
+
+    PLAY_MAP_CHUNK_BULK(State.PLAY, Direction.OUTGOING, 0x26, -1),
+    PLAY_SET_COMPRESSION(State.PLAY, Direction.OUTGOING, 0x46, -1),
+    PLAY_UPDATE_ENTITY_NBT(State.PLAY, Direction.OUTGOING, 0x49, -1),;
+
+    private State state;
+    private Direction direction;
+    private int packetID;
+    private int newPacketID = -1;
+
+    PacketType(State state, Direction direction, int packetID) {
+        this.state = state;
+        this.direction = direction;
+        this.packetID = packetID;
+        this.newPacketID = packetID;
+    }
+
+    PacketType(State state, Direction direction, int packetID, int newPacketID) {
+        this.state = state;
+        this.direction = direction;
+        this.packetID = packetID;
+        this.newPacketID = newPacketID;
+    }
+
+    public State getState() {
+        return state;
+    }
+
+    public Direction getDirection() {
+        return direction;
+    }
+
+    public int getPacketID() {
+        return packetID;
+    }
+
+    public int getNewPacketID() {
+        return newPacketID;
+    }
+
+    public static PacketType findNewPacket(State state, Direction direction, int id) {
+    	return newids.get(toShort((short) id, (short)direction.ordinal(), (short) state.ordinal()));
+    }
+
+    public static PacketType findOldPacket(State state, Direction direction, int id) {
+    	return oldids.get(toShort((short) id, (short)direction.ordinal(), (short) state.ordinal()));
+    }
+
+    public static PacketType getIncomingPacket(State state, int id) {
+        return findNewPacket(state, Direction.INCOMING, id);
+    }
+
+    public static PacketType getOutgoingPacket(State state, int id) {
+        return findOldPacket(state, Direction.OUTGOING, id);
+    }
+	
+	private static short toShort(short id, short direction, short state) {
+		return (short) ((id & 0x00FF) | (direction<<8) & 0x0F00 | (state << 12) & 0xF000);
+	}
+
+    private static HashMap<Short, PacketType> oldids = new HashMap<Short, PacketType>();
+    private static HashMap<Short, PacketType> newids = new HashMap<Short, PacketType>();
+    static {
+    	for(PacketType pt : PacketType.values()) {
+    		oldids.put(toShort((short) pt.getPacketID(), (short)pt.getDirection().ordinal(), (short)pt.getState().ordinal()), pt);
+    		newids.put(toShort((short) pt.getNewPacketID(), (short)pt.getDirection().ordinal(), (short)pt.getState().ordinal()), pt);
+    	}
+    }
+    
+}

src/main/java/us/myles/ViaVersion/slot/ItemSlotRewriter.java

@@ -0,0 +1,322 @@
+package us.myles.ViaVersion.slot;
+
+import io.netty.buffer.ByteBuf;
+import org.bukkit.Material;
+import org.spacehq.opennbt.tag.builtin.CompoundTag;
+import org.spacehq.opennbt.tag.builtin.ListTag;
+import org.spacehq.opennbt.tag.builtin.StringTag;
+import org.spacehq.opennbt.tag.builtin.Tag;
+import us.myles.ViaVersion.CancelException;
+import us.myles.ViaVersion.transformers.OutgoingTransformer;
+import us.myles.ViaVersion.util.PacketUtil;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+public class ItemSlotRewriter {
+
+    private static final Map<String, Integer> ENTTIY_NAME_TO_ID = new HashMap<>();
+    private static final Map<Integer, String> ENTTIY_ID_TO_NAME = new HashMap<>();
+    private static final Map<String, Integer> POTION_NAME_TO_ID = new HashMap<>();
+    private static final Map<Integer, String> POTION_ID_TO_NAME = new HashMap<>();
+
+    static {
+        /* Entities */
+        registerEntity(1, "Item");
+        registerEntity(2, "XPOrb");
+        registerEntity(7, "ThrownEgg");
+        registerEntity(8, "LeashKnot");
+        registerEntity(9, "Painting");
+        registerEntity(10, "Arrow");
+        registerEntity(11, "Snowball");
+        registerEntity(12, "Fireball");
+        registerEntity(13, "SmallFireball");
+        registerEntity(14, "ThrownEnderpearl");
+        registerEntity(15, "EyeOfEnderSignal");
+        registerEntity(16, "ThrownPotion");
+        registerEntity(17, "ThrownExpBottle");
+        registerEntity(18, "ItemFrame");
+        registerEntity(19, "WitherSkull");
+        registerEntity(20, "PrimedTnt");
+        registerEntity(21, "FallingSand");
+        registerEntity(22, "FireworksRocketEntity");
+        registerEntity(30, "ArmorStand");
+        registerEntity(40, "MinecartCommandBlock");
+        registerEntity(41, "Boat");
+        registerEntity(42, "MinecartRideable");
+        registerEntity(43, "MinecartChest");
+        registerEntity(44, "MinecartFurnace");
+        registerEntity(45, "MinecartTNT");
+        registerEntity(46, "MinecartHopper");
+        registerEntity(47, "MinecartSpawner");
+        registerEntity(48, "Mob");
+        registerEntity(49, "Monster");
+        registerEntity(50, "Creeper");
+        registerEntity(51, "Skeleton");
+        registerEntity(52, "Spider");
+        registerEntity(53, "Giant");
+        registerEntity(54, "Zombie");
+        registerEntity(55, "Slime");
+        registerEntity(56, "Ghast");
+        registerEntity(57, "PigZombie");
+        registerEntity(58, "Enderman");
+        registerEntity(59, "CaveSpider");
+        registerEntity(60, "Silverfish");
+        registerEntity(61, "Blaze");
+        registerEntity(62, "LavaSlime");
+        registerEntity(63, "EnderDragon");
+        registerEntity(64, "WitherBoss");
+        registerEntity(65, "Bat");
+        registerEntity(66, "Witch");
+        registerEntity(67, "Endermite");
+        registerEntity(68, "Guardian");
+        registerEntity(90, "Pig");
+        registerEntity(91, "Sheep");
+        registerEntity(92, "Cow");
+        registerEntity(93, "Chicken");
+        registerEntity(94, "Squid");
+        registerEntity(95, "Wolf");
+        registerEntity(96, "MushroomCow");
+        registerEntity(97, "SnowMan");
+        registerEntity(98, "Ozelot");
+        registerEntity(99, "VillagerGolem");
+        registerEntity(100, "EntityHorse");
+        registerEntity(101, "Rabbit");
+        registerEntity(120, "Villager");
+        registerEntity(200, "EnderCrystal");
+
+        /* Potions */
+        registerPotion(0, "water");
+        registerPotion(64, "mundane");
+        registerPotion(32, "thick");
+        registerPotion(16, "awkward");
+
+        registerPotion(8198, "night_vision");
+        registerPotion(8262, "long_night_vision");
+
+        registerPotion(8206, "invisibility");
+        registerPotion(8270, "long_invisibility");
+
+        registerPotion(8203, "leaping");
+        registerPotion(8267, "long_leaping");
+        registerPotion(8235, "strong_leaping");
+
+        registerPotion(8195, "fire_resistance");
+        registerPotion(8259, "long_fire_resistance");
+
+        registerPotion(8194, "swiftness");
+        registerPotion(8258, "long_swiftness");
+        registerPotion(8226, "strong_swiftness");
+
+        registerPotion(8202, "slowness");
+        registerPotion(8266, "long_slowness");
+
+        registerPotion(8205, "water_breathing");
+        registerPotion(8269, "long_water_breathing");
+
+        registerPotion(8197, "healing");
+        registerPotion(8229, "strong_healing");
+
+        registerPotion(8204, "harming");
+        registerPotion(8236, "strong_harming");
+
+        registerPotion(8196, "poison");
+        registerPotion(8260, "long_poison");
+        registerPotion(8228, "strong_poison");
+
+        registerPotion(8193, "regeneration");
+        registerPotion(8257, "long_regeneration");
+        registerPotion(8225, "strong_regeneration");
+
+        registerPotion(8201, "strength");
+        registerPotion(8265, "long_strength");
+        registerPotion(8233, "strong_strength");
+
+        registerPotion(8200, "weakness");
+        registerPotion(8264, "long_weakness");
+
+    }
+
+    public static void rewrite1_9To1_8(ByteBuf input, ByteBuf output) throws CancelException {
+        try {
+            ItemStack item = readItemStack(input);
+            fixIdsFrom1_9To1_8(item);
+            writeItemStack(item, output);
+        } catch (Exception e) {
+            System.out.println("Error while rewriting an item slot.");
+            e.printStackTrace();
+            throw new CancelException();
+        }
+    }
+
+    public static void rewrite1_8To1_9(ByteBuf input, ByteBuf output) throws CancelException {
+        try {
+            ItemStack item = readItemStack(input);
+            fixIdsFrom1_8To1_9(item);
+            writeItemStack(item, output);
+        } catch (Exception e) {
+            System.out.println("Error while rewriting an item slot.");
+            e.printStackTrace();
+            throw new CancelException();
+        }
+    }
+
+    public static void fixIdsFrom1_9To1_8(ItemStack item) {
+        if (item != null) {
+            if (item.id == Material.MONSTER_EGG.getId() && item.data == 0) {
+                CompoundTag tag = item.tag;
+                int data = 0;
+                if (tag != null && tag.get("EntityTag") instanceof CompoundTag) {
+                    CompoundTag entityTag = tag.get("EntityTag");
+                    if (entityTag.get("id") instanceof StringTag) {
+                        StringTag id = entityTag.get("id");
+                        if (ENTTIY_NAME_TO_ID.containsKey(id.getValue()))
+                            data = ENTTIY_NAME_TO_ID.get(id.getValue());
+                    }
+                }
+                item.tag = null;
+                item.data = (short) data;
+            }
+            if (item.id == Material.POTION.getId()) {
+                CompoundTag tag = item.tag;
+                int data = 0;
+                if (tag != null && tag.get("Potion") instanceof StringTag) {
+                    StringTag potion = tag.get("Potion");
+                    String potionName = potion.getValue().replace("minecraft:", "");
+                    if (POTION_NAME_TO_ID.containsKey(potionName)) {
+                        data = POTION_NAME_TO_ID.get(potionName);
+                    }
+                }
+                item.tag = null;
+                item.data = (short) data;
+            }
+            if (item.id == 438) {
+                CompoundTag tag = item.tag;
+                int data = 0;
+                item.id = (short) Material.POTION.getId();
+                if (tag != null && tag.get("Potion") instanceof StringTag) {
+                    StringTag potion = tag.get("Potion");
+                    String potionName = potion.getValue().replace("minecraft:", "");
+                    if (POTION_NAME_TO_ID.containsKey(potionName)) {
+                        data = POTION_NAME_TO_ID.get(potionName) + 8192;
+                    }
+                }
+                item.tag = null;
+                item.data = (short) data;
+            }
+        }
+    }
+
+    public static void fixIdsFrom1_8To1_9(ItemStack item) {
+        if (item != null) {
+            if (item.id == Material.MONSTER_EGG.getId() && item.data != 0) {
+                CompoundTag tag = item.tag;
+                if (tag == null) {
+                    tag = new CompoundTag("tag");
+                }
+                CompoundTag entityTag = new CompoundTag("EntityTag");
+                if (ENTTIY_ID_TO_NAME.containsKey((int) item.data)) {
+                    StringTag id = new StringTag("id", ENTTIY_ID_TO_NAME.get((int) item.data));
+                    entityTag.put(id);
+                    tag.put(entityTag);
+                }
+                item.tag = tag;
+                item.data = 0;
+            }
+            if (item.id == Material.POTION.getId()) {
+                CompoundTag tag = item.tag;
+                if (tag == null) {
+                    tag = new CompoundTag("tag");
+                }
+                if (item.data >= 16384) {
+                    item.id = 438; // splash id
+                    item.data = (short) (item.data - 8192);
+                }
+                if (POTION_ID_TO_NAME.containsKey((int) item.data)) {
+                    String name = POTION_ID_TO_NAME.get((int) item.data);
+                    StringTag potion = new StringTag("Potion", "minecraft:" + name);
+                    tag.put(potion);
+                }
+                item.tag = tag;
+                item.data = 0;
+            }
+            if (item.id == Material.WRITTEN_BOOK.getId()) {
+                CompoundTag tag = item.tag;
+                if (tag == null) {
+                    tag = new CompoundTag("tag");
+                }
+                ListTag pages = tag.get("pages");
+                if (pages == null) {
+                    pages = new ListTag("pages", Collections.<Tag>singletonList(new StringTag(OutgoingTransformer.fixJson(""))));
+                    tag.put(pages);
+                    item.tag = tag;
+                    return;
+                }
+
+                for (int i = 0; i < pages.size(); i++) {
+                    if (!(pages.get(i) instanceof StringTag))
+                        continue;
+                    StringTag page = pages.get(i);
+                    page.setValue(OutgoingTransformer.fixJson(page.getValue()));
+                }
+                item.tag = tag;
+            }
+        }
+    }
+
+    public static ItemStack readItemStack(ByteBuf input) throws IOException {
+        short id = input.readShort();
+        if (id < 0) {
+
+            return null;
+        } else {
+            ItemStack item = new ItemStack();
+            item.id = id;
+            item.amount = input.readByte();
+            item.data = input.readShort();
+            item.tag = PacketUtil.readNBT(input);
+            return item;
+        }
+    }
+
+    public static void writeItemStack(ItemStack item, ByteBuf output) throws IOException {
+        if (item == null) {
+            output.writeShort(-1);
+        } else {
+            output.writeShort(item.id);
+            output.writeByte(item.amount);
+            output.writeShort(item.data);
+            PacketUtil.writeNBT(output, item.tag);
+        }
+    }
+
+    private static void registerEntity(Integer id, String name) {
+        ENTTIY_ID_TO_NAME.put(id, name);
+        ENTTIY_NAME_TO_ID.put(name, id);
+    }
+
+    private static void registerPotion(Integer id, String name) {
+        POTION_ID_TO_NAME.put(id, name);
+        POTION_NAME_TO_ID.put(name, id);
+    }
+
+    public static class ItemStack {
+
+        public short id;
+        public byte amount;
+        public short data;
+        public CompoundTag tag;
+
+        public static ItemStack fromBukkit(org.bukkit.inventory.ItemStack stack) {
+            if(stack == null) return null;
+            ItemStack item = new ItemStack();
+            item.id = (short) stack.getTypeId();
+            item.amount = (byte) stack.getAmount();
+            item.data = stack.getData().getData();
+            // TODO: nbt
+            return item;
+        }
+    }
+}

src/main/java/us/myles/ViaVersion/sounds/SoundCategory.java

@@ -0,0 +1,25 @@
+package us.myles.ViaVersion.sounds;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+@Getter
+public enum SoundCategory {
+
+
+    MASTER("master", 0),
+    MUSIC("music", 1),
+    RECORD("record", 2),
+    WEATHER("weather", 3),
+    BLOCK("block", 4),
+    HOSTILE("hostile", 5),
+    NEUTRAL("neutral", 6),
+    PLAYER("player", 7),
+    AMBIENT("ambient", 8),
+    VOICE("voice", 9);
+
+    private final String name;
+    private final int id;
+
+}

src/main/java/us/myles/ViaVersion/sounds/SoundEffect.java

@@ -0,0 +1,283 @@
+package us.myles.ViaVersion.sounds;
+
+import lombok.Getter;
+
+@Getter
+public enum SoundEffect {
+
+    MOB_HORSE_ZOMBIE_IDLE("mob.horse.zombie.idle", "entity.zombie_horse.ambient", SoundCategory.NEUTRAL),
+    NOTE_SNARE("note.snare", "block.note.snare", SoundCategory.RECORD),
+    RANDOM_WOOD_CLICK("random.wood_click", "block.wood_button.click_on", SoundCategory.BLOCK),
+    DIG_GRAVEL("dig.gravel", "block.gravel.place", SoundCategory.BLOCK),
+    RANDOM_BOWHIT("random.bowhit", "block.tripwire.detach", SoundCategory.NEUTRAL),
+    DIG_GLASS("dig.glass", "block.glass.break", SoundCategory.BLOCK),
+    MOB_ZOMBIE_SAY("mob.zombie.say", "entity.zombie_villager.ambient", SoundCategory.HOSTILE),
+    MOB_PIG_DEATH("mob.pig.death", "entity.pig.death", SoundCategory.NEUTRAL),
+    MOB_HORSE_DONKEY_HIT("mob.horse.donkey.hit", "entity.donkey.hurt", SoundCategory.NEUTRAL),
+    GAME_NEUTRAL_SWIM("game.neutral.swim", "entity.player.swim", SoundCategory.NEUTRAL),
+    GAME_PLAYER_SWIM("game.player.swim", "entity.player.swim", SoundCategory.PLAYER),
+    MOB_ENDERMEN_IDLE("mob.endermen.idle", "entity.endermen.ambient", SoundCategory.HOSTILE),
+    PORTAL_PORTAL("portal.portal", "block.portal.ambient", SoundCategory.BLOCK),
+    RANDOM_FIZZ("random.fizz", "entity.generic.extinguish_fire", SoundCategory.BLOCK),
+    NOTE_HARP("note.harp", "block.note.harp", SoundCategory.RECORD),
+    STEP_SNOW("step.snow", "block.snow.step", SoundCategory.NEUTRAL),
+    RANDOM_SUCCESSFUL_HIT("random.successful_hit", "entity.arrow.hit_player", SoundCategory.PLAYER),
+    MOB_ZOMBIEPIG_ZPIGHURT("mob.zombiepig.zpighurt", "entity.zombie_pig.hurt", SoundCategory.HOSTILE),
+    MOB_WOLF_HOWL("mob.wolf.howl", "entity.wolf.howl", SoundCategory.NEUTRAL),
+    FIREWORKS_LAUNCH("fireworks.launch", "entity.firework.launch", SoundCategory.AMBIENT),
+    MOB_COW_HURT("mob.cow.hurt", "entity.cow.death", SoundCategory.NEUTRAL),
+    FIREWORKS_LARGEBLAST("fireworks.largeBlast", "entity.firework.large_blast", SoundCategory.AMBIENT),
+    MOB_BLAZE_HIT("mob.blaze.hit", "entity.blaze.hurt", SoundCategory.HOSTILE),
+    MOB_VILLAGER_DEATH("mob.villager.death", "entity.villager.death", SoundCategory.NEUTRAL),
+    MOB_BLAZE_DEATH("mob.blaze.death", "entity.blaze.death", SoundCategory.HOSTILE),
+    MOB_HORSE_ZOMBIE_DEATH("mob.horse.zombie.death", "entity.zombie_horse.death", SoundCategory.NEUTRAL),
+    MOB_SILVERFISH_KILL("mob.silverfish.kill", "entity.endermite.death", SoundCategory.HOSTILE),
+    MOB_WOLF_PANTING("mob.wolf.panting", "entity.wolf.pant", SoundCategory.NEUTRAL),
+    NOTE_BASS("note.bass", "null", SoundCategory.RECORD),
+    DIG_STONE("dig.stone", "block.glass.place", SoundCategory.BLOCK),
+    MOB_ENDERMEN_STARE("mob.endermen.stare", "entity.endermen.stare", SoundCategory.HOSTILE),
+    GAME_PLAYER_SWIM_SPLASH("game.player.swim.splash", "entity.generic.splash", SoundCategory.BLOCK),
+    MOB_SLIME_SMALL("mob.slime.small", "block.slime.hit", SoundCategory.HOSTILE),
+    MOB_GHAST_DEATH("mob.ghast.death", "entity.ghast.death", SoundCategory.HOSTILE),
+    MOB_GUARDIAN_ATTACK("mob.guardian.attack", "entity.guardian.attack", SoundCategory.HOSTILE),
+    RANDOM_CLICK("random.click", "block.wood_pressureplate.click_on", SoundCategory.BLOCK),
+    MOB_ZOMBIEPIG_ZPIG("mob.zombiepig.zpig", "entity.zombie_pig.ambient", SoundCategory.HOSTILE),
+    GAME_PLAYER_DIE("game.player.die", "entity.player.death", SoundCategory.PLAYER),
+    FIREWORKS_TWINKLE_FAR("fireworks.twinkle_far", "entity.firework.twinkle_far", SoundCategory.AMBIENT),
+    MOB_GUARDIAN_LAND_IDLE("mob.guardian.land.idle", "entity.guardian.ambient_land", SoundCategory.HOSTILE),
+    DIG_GRASS("dig.grass", "block.grass.place", SoundCategory.BLOCK),
+    MOB_SKELETON_STEP("mob.skeleton.step", "entity.skeleton.step", SoundCategory.HOSTILE),
+    MOB_WITHER_DEATH("mob.wither.death", "entity.wither.death", SoundCategory.HOSTILE),
+    MOB_WOLF_HURT("mob.wolf.hurt", "entity.wolf.hurt", SoundCategory.NEUTRAL),
+    MOB_HORSE_LEATHER("mob.horse.leather", "entity.horse.saddle", SoundCategory.NEUTRAL),
+    MOB_BAT_LOOP("mob.bat.loop", "entity.bat.loop", SoundCategory.NEUTRAL),
+    MOB_GHAST_SCREAM("mob.ghast.scream", "entity.ghast.hurt", SoundCategory.HOSTILE),
+    GAME_PLAYER_HURT("game.player.hurt", "entity.player.death", SoundCategory.PLAYER),
+    GAME_NEUTRAL_DIE("game.neutral.die", "entity.player.death", SoundCategory.NEUTRAL),
+    MOB_CREEPER_DEATH("mob.creeper.death", "entity.creeper.death", SoundCategory.HOSTILE),
+    MOB_HORSE_GALLOP("mob.horse.gallop", "entity.horse.gallop", SoundCategory.NEUTRAL),
+    MOB_WITHER_SPAWN("mob.wither.spawn", "entity.wither.spawn", SoundCategory.HOSTILE),
+    MOB_ENDERMEN_HIT("mob.endermen.hit", "entity.endermen.hurt", SoundCategory.HOSTILE),
+    MOB_CREEPER_SAY("mob.creeper.say", "entity.creeper.hurt", SoundCategory.HOSTILE),
+    MOB_HORSE_WOOD("mob.horse.wood", "entity.horse.step_wood", SoundCategory.NEUTRAL),
+    MOB_ZOMBIE_UNFECT("mob.zombie.unfect", "entity.zombie_villager.converted", SoundCategory.HOSTILE),
+    RANDOM_ANVIL_USE("random.anvil_use", "block.anvil.use", SoundCategory.BLOCK),
+    RANDOM_CHESTCLOSED("random.chestclosed", "block.enderchest.close", SoundCategory.BLOCK),
+    MOB_SHEEP_SHEAR("mob.sheep.shear", "entity.sheep.shear", SoundCategory.NEUTRAL),
+    RANDOM_POP("random.pop", "entity.item.pickup", SoundCategory.PLAYER),
+    MOB_BAT_DEATH("mob.bat.death", "entity.bat.death", SoundCategory.NEUTRAL),
+    DIG_WOOD("dig.wood", "block.ladder.break", SoundCategory.BLOCK),
+    MOB_HORSE_DONKEY_DEATH("mob.horse.donkey.death", "entity.donkey.death", SoundCategory.NEUTRAL),
+    FIREWORKS_BLAST("fireworks.blast", "entity.firework.blast", SoundCategory.AMBIENT),
+    MOB_ZOMBIEPIG_ZPIGANGRY("mob.zombiepig.zpigangry", "entity.zombie_pig.angry", SoundCategory.HOSTILE),
+    GAME_HOSTILE_SWIM("game.hostile.swim", "entity.player.swim", SoundCategory.HOSTILE),
+    MOB_GUARDIAN_FLOP("mob.guardian.flop", "entity.guardian.flop", SoundCategory.HOSTILE),
+    MOB_VILLAGER_YES("mob.villager.yes", "entity.villager.yes", SoundCategory.NEUTRAL),
+    MOB_GHAST_CHARGE("mob.ghast.charge", "entity.ghast.warn", SoundCategory.HOSTILE),
+    CREEPER_PRIMED("creeper.primed", "entity.creeper.primed", SoundCategory.HOSTILE),
+    DIG_SAND("dig.sand", "block.sand.break", SoundCategory.BLOCK),
+    MOB_CHICKEN_SAY("mob.chicken.say", "entity.chicken.ambient", SoundCategory.NEUTRAL),
+    RANDOM_DOOR_CLOSE("random.door_close", "null", SoundCategory.BLOCK),
+    MOB_GUARDIAN_ELDER_DEATH("mob.guardian.elder.death", "entity.elder_guardian.death", SoundCategory.HOSTILE),
+    FIREWORKS_TWINKLE("fireworks.twinkle", "entity.firework.twinkle", SoundCategory.AMBIENT),
+    MOB_HORSE_SKELETON_DEATH("mob.horse.skeleton.death", "entity.skeleton_horse.death", SoundCategory.NEUTRAL),
+    AMBIENT_WEATHER_RAIN("ambient.weather.rain", "weather.rain.above", SoundCategory.WEATHER),
+    PORTAL_TRIGGER("portal.trigger", "block.portal.trigger", SoundCategory.BLOCK),
+    RANDOM_CHESTOPEN("random.chestopen", "block.enderchest.open", SoundCategory.BLOCK),
+    MOB_HORSE_LAND("mob.horse.land", "entity.horse.land", SoundCategory.NEUTRAL),
+    MOB_SILVERFISH_STEP("mob.silverfish.step", "entity.silverfish.step", SoundCategory.HOSTILE),
+    MOB_BAT_TAKEOFF("mob.bat.takeoff", "entity.bat.takeoff", SoundCategory.NEUTRAL),
+    MOB_VILLAGER_NO("mob.villager.no", "entity.villager.no", SoundCategory.NEUTRAL),
+    GAME_HOSTILE_HURT_FALL_BIG("game.hostile.hurt.fall.big", "entity.hostile.big_fall", SoundCategory.HOSTILE),
+    MOB_IRONGOLEM_WALK("mob.irongolem.walk", "entity.irongolem.step", SoundCategory.NEUTRAL),
+    NOTE_HAT("note.hat", "block.note.hat", SoundCategory.RECORD),
+    MOB_ZOMBIE_METAL("mob.zombie.metal", "entity.zombie.attack_iron_door", SoundCategory.HOSTILE),
+    MOB_VILLAGER_HAGGLE("mob.villager.haggle", "entity.villager.trading", SoundCategory.NEUTRAL),
+    MOB_GHAST_FIREBALL("mob.ghast.fireball", "entity.blaze.shoot", SoundCategory.HOSTILE),
+    MOB_IRONGOLEM_DEATH("mob.irongolem.death", "entity.irongolem.death", SoundCategory.NEUTRAL),
+    RANDOM_BREAK("random.break", "item.shield.break", SoundCategory.PLAYER),
+    MOB_ZOMBIE_REMEDY("mob.zombie.remedy", "entity.zombie_villager.cure", SoundCategory.HOSTILE),
+    RANDOM_BOW("random.bow", "entity.splash_potion.throw", SoundCategory.NEUTRAL),
+    MOB_VILLAGER_IDLE("mob.villager.idle", "entity.villager.ambient", SoundCategory.NEUTRAL),
+    STEP_CLOTH("step.cloth", "block.cloth.fall", SoundCategory.NEUTRAL),
+    MOB_SILVERFISH_HIT("mob.silverfish.hit", "entity.endermite.hurt", SoundCategory.HOSTILE),
+    LIQUID_LAVA("liquid.lava", "block.lava.ambient", SoundCategory.BLOCK),
+    GAME_NEUTRAL_HURT_FALL_BIG("game.neutral.hurt.fall.big", "entity.hostile.big_fall", SoundCategory.NEUTRAL),
+    FIRE_FIRE("fire.fire", "block.fire.ambient", SoundCategory.BLOCK),
+    MOB_ZOMBIE_WOOD("mob.zombie.wood", "entity.zombie.attack_door_wood", SoundCategory.HOSTILE),
+    MOB_CHICKEN_STEP("mob.chicken.step", "entity.chicken.step", SoundCategory.NEUTRAL),
+    MOB_GUARDIAN_LAND_HIT("mob.guardian.land.hit", "entity.guardian.hurt_land", SoundCategory.HOSTILE),
+    MOB_CHICKEN_PLOP("mob.chicken.plop", "entity.donkey.chest", SoundCategory.NEUTRAL),
+    MOB_ENDERDRAGON_WINGS("mob.enderdragon.wings", "entity.enderdragon.flap", SoundCategory.HOSTILE),
+    STEP_GRASS("step.grass", "block.grass.hit", SoundCategory.NEUTRAL),
+    MOB_HORSE_BREATHE("mob.horse.breathe", "entity.horse.breathe", SoundCategory.NEUTRAL),
+    GAME_PLAYER_HURT_FALL_BIG("game.player.hurt.fall.big", "entity.hostile.big_fall", SoundCategory.PLAYER),
+    MOB_HORSE_DONKEY_IDLE("mob.horse.donkey.idle", "entity.donkey.ambient", SoundCategory.NEUTRAL),
+    MOB_SPIDER_STEP("mob.spider.step", "entity.spider.step", SoundCategory.HOSTILE),
+    GAME_NEUTRAL_HURT("game.neutral.hurt", "entity.player.death", SoundCategory.NEUTRAL),
+    MOB_COW_SAY("mob.cow.say", "entity.cow.ambient", SoundCategory.NEUTRAL),
+    MOB_HORSE_JUMP("mob.horse.jump", "entity.horse.jump", SoundCategory.NEUTRAL),
+    MOB_HORSE_SOFT("mob.horse.soft", "entity.horse.step", SoundCategory.NEUTRAL),
+    GAME_NEUTRAL_SWIM_SPLASH("game.neutral.swim.splash", "entity.generic.splash", SoundCategory.NEUTRAL),
+    MOB_GUARDIAN_HIT("mob.guardian.hit", "entity.guardian.hurt", SoundCategory.HOSTILE),
+    MOB_ENDERDRAGON_END("mob.enderdragon.end", "entity.enderdragon.death", SoundCategory.HOSTILE),
+    MOB_ZOMBIE_STEP("mob.zombie.step", "entity.zombie.step", SoundCategory.HOSTILE),
+    MOB_ENDERDRAGON_GROWL("mob.enderdragon.growl", "entity.enderdragon.growl", SoundCategory.HOSTILE),
+    MOB_WOLF_SHAKE("mob.wolf.shake", "entity.wolf.shake", SoundCategory.NEUTRAL),
+    MOB_ENDERMEN_DEATH("mob.endermen.death", "entity.endermen.death", SoundCategory.HOSTILE),
+    RANDOM_ANVIL_LAND("random.anvil_land", "block.anvil.land", SoundCategory.BLOCK),
+    GAME_HOSTILE_HURT("game.hostile.hurt", "entity.player.death", SoundCategory.HOSTILE),
+    MINECART_INSIDE("minecart.inside", "entity.minecart.inside", SoundCategory.PLAYER),
+    MOB_SLIME_BIG("mob.slime.big", "entity.slime.death", SoundCategory.HOSTILE),
+    LIQUID_WATER("liquid.water", "block.water.ambient", SoundCategory.BLOCK),
+    MOB_PIG_SAY("mob.pig.say", "entity.pig.ambient", SoundCategory.NEUTRAL),
+    MOB_WITHER_SHOOT("mob.wither.shoot", "entity.wither.shoot", SoundCategory.HOSTILE),
+    ITEM_FIRECHARGE_USE("item.fireCharge.use", "entity.blaze.shoot", SoundCategory.BLOCK),
+    STEP_SAND("step.sand", "block.sand.fall", SoundCategory.NEUTRAL),
+    MOB_IRONGOLEM_HIT("mob.irongolem.hit", "entity.irongolem.hurt", SoundCategory.NEUTRAL),
+    MOB_HORSE_DEATH("mob.horse.death", "entity.horse.death", SoundCategory.NEUTRAL),
+    MOB_BAT_HURT("mob.bat.hurt", "entity.bat.hurt", SoundCategory.NEUTRAL),
+    MOB_GHAST_AFFECTIONATE_SCREAM("mob.ghast.affectionate_scream", "entity.ghast.scream", SoundCategory.HOSTILE),
+    MOB_GUARDIAN_ELDER_IDLE("mob.guardian.elder.idle", "entity.elder_guardian.ambient", SoundCategory.HOSTILE),
+    MOB_ZOMBIEPIG_ZPIGDEATH("mob.zombiepig.zpigdeath", "entity.zombie_pig.death", SoundCategory.HOSTILE),
+    AMBIENT_WEATHER_THUNDER("ambient.weather.thunder", "entity.lightning.thunder", SoundCategory.WEATHER),
+    MINECART_BASE("minecart.base", "entity.minecart.riding", SoundCategory.NEUTRAL),
+    STEP_LADDER("step.ladder", "block.ladder.hit", SoundCategory.NEUTRAL),
+    MOB_HORSE_DONKEY_ANGRY("mob.horse.donkey.angry", "entity.donkey.angry", SoundCategory.NEUTRAL),
+    AMBIENT_CAVE_CAVE("ambient.cave.cave", "ambient.cave", SoundCategory.AMBIENT),
+    FIREWORKS_BLAST_FAR("fireworks.blast_far", "entity.firework.blast_far", SoundCategory.AMBIENT),
+    GAME_NEUTRAL_HURT_FALL_SMALL("game.neutral.hurt.fall.small", "entity.generic.small_fall", SoundCategory.NEUTRAL),
+    GAME_HOSTILE_SWIM_SPLASH("game.hostile.swim.splash", "entity.generic.splash", SoundCategory.HOSTILE),
+    RANDOM_DRINK("random.drink", "entity.generic.drink", SoundCategory.PLAYER),
+    GAME_HOSTILE_DIE("game.hostile.die", "entity.player.death", SoundCategory.HOSTILE),
+    MOB_CAT_HISS("mob.cat.hiss", "entity.cat.hiss", SoundCategory.NEUTRAL),
+    NOTE_BD("note.bd", "block.note.basedrum", SoundCategory.RECORD),
+    MOB_SPIDER_SAY("mob.spider.say", "entity.spider.hurt", SoundCategory.HOSTILE),
+    STEP_STONE("step.stone", "block.anvil.hit", SoundCategory.NEUTRAL),
+    RANDOM_LEVELUP("random.levelup", "entity.player.levelup", SoundCategory.PLAYER),
+    LIQUID_LAVAPOP("liquid.lavapop", "block.lava.pop", SoundCategory.BLOCK),
+    MOB_SHEEP_SAY("mob.sheep.say", "entity.sheep.ambient", SoundCategory.NEUTRAL),
+    MOB_SKELETON_SAY("mob.skeleton.say", "entity.skeleton.ambient", SoundCategory.HOSTILE),
+    MOB_BLAZE_BREATHE("mob.blaze.breathe", "entity.blaze.ambient", SoundCategory.HOSTILE),
+    MOB_BAT_IDLE("mob.bat.idle", "entity.bat.ambient", SoundCategory.NEUTRAL),
+    MOB_MAGMACUBE_BIG("mob.magmacube.big", "entity.magmacube.squish", SoundCategory.HOSTILE),
+    MOB_HORSE_IDLE("mob.horse.idle", "entity.horse.ambient", SoundCategory.NEUTRAL),
+    GAME_HOSTILE_HURT_FALL_SMALL("game.hostile.hurt.fall.small", "entity.generic.small_fall", SoundCategory.HOSTILE),
+    MOB_HORSE_ZOMBIE_HIT("mob.horse.zombie.hit", "entity.zombie_horse.hurt", SoundCategory.NEUTRAL),
+    MOB_IRONGOLEM_THROW("mob.irongolem.throw", "entity.irongolem.attack", SoundCategory.NEUTRAL),
+    DIG_CLOTH("dig.cloth", "block.cloth.place", SoundCategory.BLOCK),
+    STEP_GRAVEL("step.gravel", "block.gravel.hit", SoundCategory.NEUTRAL),
+    MOB_SILVERFISH_SAY("mob.silverfish.say", "entity.silverfish.ambient", SoundCategory.HOSTILE),
+    MOB_CAT_PURR("mob.cat.purr", "entity.cat.purr", SoundCategory.NEUTRAL),
+    MOB_ZOMBIE_INFECT("mob.zombie.infect", "entity.zombie.infect", SoundCategory.HOSTILE),
+    RANDOM_EAT("random.eat", "entity.generic.eat", SoundCategory.PLAYER),
+    MOB_WOLF_BARK("mob.wolf.bark", "entity.wolf.ambient", SoundCategory.NEUTRAL),
+    GAME_TNT_PRIMED("game.tnt.primed", "entity.creeper.primed", SoundCategory.BLOCK),
+    MOB_SHEEP_STEP("mob.sheep.step", "entity.sheep.step", SoundCategory.NEUTRAL),
+    MOB_ZOMBIE_DEATH("mob.zombie.death", "entity.zombie.death", SoundCategory.HOSTILE),
+    RANDOM_DOOR_OPEN("random.door_open", "null", SoundCategory.BLOCK),
+    MOB_ENDERMEN_PORTAL("mob.endermen.portal", "entity.endermen.teleport", SoundCategory.HOSTILE),
+    MOB_HORSE_ANGRY("mob.horse.angry", "entity.horse.angry", SoundCategory.NEUTRAL),
+    MOB_WOLF_GROWL("mob.wolf.growl", "entity.wolf.growl", SoundCategory.NEUTRAL),
+    DIG_SNOW("dig.snow", "block.snow.place", SoundCategory.BLOCK),
+    TILE_PISTON_OUT("tile.piston.out", "block.piston.extend", SoundCategory.BLOCK),
+    RANDOM_BURP("random.burp", "entity.player.burp", SoundCategory.PLAYER),
+    MOB_COW_STEP("mob.cow.step", "entity.cow.step", SoundCategory.NEUTRAL),
+    MOB_WITHER_HURT("mob.wither.hurt", "entity.wither.hurt", SoundCategory.HOSTILE),
+    MOB_GUARDIAN_LAND_DEATH("mob.guardian.land.death", "entity.elder_guardian.death_land", SoundCategory.HOSTILE),
+    MOB_CHICKEN_HURT("mob.chicken.hurt", "entity.chicken.death", SoundCategory.NEUTRAL),
+    MOB_WOLF_STEP("mob.wolf.step", "entity.wolf.step", SoundCategory.NEUTRAL),
+    MOB_WOLF_DEATH("mob.wolf.death", "entity.wolf.death", SoundCategory.NEUTRAL),
+    MOB_WOLF_WHINE("mob.wolf.whine", "entity.wolf.whine", SoundCategory.NEUTRAL),
+    NOTE_PLING("note.pling", "block.note.pling", SoundCategory.RECORD),
+    GAME_PLAYER_HURT_FALL_SMALL("game.player.hurt.fall.small", "entity.generic.small_fall", SoundCategory.PLAYER),
+    MOB_CAT_PURREOW("mob.cat.purreow", "entity.cat.purreow", SoundCategory.NEUTRAL),
+    FIREWORKS_LARGEBLAST_FAR("fireworks.largeBlast_far", "entity.firework.large_blast_far", SoundCategory.AMBIENT),
+    MOB_SKELETON_HURT("mob.skeleton.hurt", "entity.skeleton.hurt", SoundCategory.HOSTILE),
+    MOB_SPIDER_DEATH("mob.spider.death", "entity.spider.death", SoundCategory.HOSTILE),
+    RANDOM_ANVIL_BREAK("random.anvil_break", "block.anvil.destroy", SoundCategory.BLOCK),
+    MOB_WITHER_IDLE("mob.wither.idle", "entity.wither.ambient", SoundCategory.HOSTILE),
+    MOB_GUARDIAN_ELDER_HIT("mob.guardian.elder.hit", "entity.elder_guardian.hurt", SoundCategory.HOSTILE),
+    MOB_ENDERMEN_SCREAM("mob.endermen.scream", "entity.endermen.scream", SoundCategory.HOSTILE),
+    MOB_CAT_HITT("mob.cat.hitt", "entity.cat.hurt", SoundCategory.NEUTRAL),
+    MOB_MAGMACUBE_SMALL("mob.magmacube.small", "entity.small_magmacube.squish", SoundCategory.HOSTILE),
+    FIRE_IGNITE("fire.ignite", "item.flintandsteel.use", SoundCategory.BLOCK, true),
+    MOB_ENDERDRAGON_HIT("mob.enderdragon.hit", "entity.enderdragon.hurt", SoundCategory.HOSTILE),
+    MOB_ZOMBIE_HURT("mob.zombie.hurt", "entity.zombie_villager.hurt", SoundCategory.HOSTILE),
+    RANDOM_EXPLODE("random.explode", "block.end_gateway.spawn", SoundCategory.BLOCK),
+    MOB_SLIME_ATTACK("mob.slime.attack", "entity.slime.attack", SoundCategory.HOSTILE),
+    MOB_MAGMACUBE_JUMP("mob.magmacube.jump", "entity.magmacube.jump", SoundCategory.HOSTILE),
+    RANDOM_SPLASH("random.splash", "entity.bobber.splash", SoundCategory.PLAYER),
+    MOB_HORSE_SKELETON_HIT("mob.horse.skeleton.hit", "entity.skeleton_horse.hurt", SoundCategory.NEUTRAL),
+    MOB_GHAST_MOAN("mob.ghast.moan", "entity.ghast.ambient", SoundCategory.HOSTILE),
+    MOB_GUARDIAN_CURSE("mob.guardian.curse", "entity.elder_guardian.curse", SoundCategory.HOSTILE),
+    GAME_POTION_SMASH("game.potion.smash", "block.glass.break", SoundCategory.NEUTRAL),
+    NOTE_BASSATTACK("note.bassattack", "block.note.bass", SoundCategory.RECORD),
+    GUI_BUTTON_PRESS("gui.button.press", "block.wood_pressureplate.click_on", SoundCategory.MASTER),
+    RANDOM_ORB("random.orb", "entity.experience_orb.pickup", SoundCategory.PLAYER),
+    MOB_ZOMBIE_WOODBREAK("mob.zombie.woodbreak", "entity.zombie.break_door_wood", SoundCategory.HOSTILE),
+    MOB_HORSE_ARMOR("mob.horse.armor", "entity.horse.armor", SoundCategory.NEUTRAL),
+    TILE_PISTON_IN("tile.piston.in", "block.piston.contract", SoundCategory.BLOCK),
+    MOB_CAT_MEOW("mob.cat.meow", "entity.cat.ambient", SoundCategory.NEUTRAL),
+    MOB_PIG_STEP("mob.pig.step", "entity.pig.step", SoundCategory.NEUTRAL),
+    STEP_WOOD("step.wood", "block.wood.step", SoundCategory.NEUTRAL),
+    PORTAL_TRAVEL("portal.travel", "block.portal.travel", SoundCategory.PLAYER),
+    MOB_GUARDIAN_DEATH("mob.guardian.death", "entity.guardian.death", SoundCategory.HOSTILE),
+    MOB_SKELETON_DEATH("mob.skeleton.death", "entity.skeleton.death", SoundCategory.HOSTILE),
+    MOB_HORSE_HIT("mob.horse.hit", "entity.horse.hurt", SoundCategory.NEUTRAL),
+    MOB_VILLAGER_HIT("mob.villager.hit", "entity.villager.hurt", SoundCategory.NEUTRAL),
+    MOB_HORSE_SKELETON_IDLE("mob.horse.skeleton.idle", "entity.skeleton_horse.ambient", SoundCategory.NEUTRAL),
+    RECORDS_CHIRP("records.chirp", "record.chirp", SoundCategory.RECORD),
+    MOB_RABBIT_HURT("mob.rabbit.hurt", "entity.rabbit.hurt", SoundCategory.NEUTRAL),
+    RECORDS_STAL("records.stal", "record.stal", SoundCategory.RECORD),
+    MUSIC_GAME_NETHER("music.game.nether", "music.nether", SoundCategory.MUSIC),
+    MUSIC_MENU("music.menu", "music.menu", SoundCategory.MUSIC),
+    RECORDS_MELLOHI("records.mellohi", "record.mellohi", SoundCategory.RECORD),
+    RECORDS_CAT("records.cat", "record.cat", SoundCategory.RECORD),
+    RECORDS_FAR("records.far", "record.far", SoundCategory.RECORD),
+    MUSIC_GAME_END_DRAGON("music.game.end.dragon", "music.dragon", SoundCategory.MUSIC),
+    MOB_RABBIT_DEATH("mob.rabbit.death", "entity.rabbit.death", SoundCategory.NEUTRAL),
+    MOB_RABBIT_IDLE("mob.rabbit.idle", "entity.rabbit.ambient", SoundCategory.NEUTRAL),
+    MUSIC_GAME_END("music.game.end", "music.end", SoundCategory.MUSIC),
+    MUSIC_GAME("music.game", "music.game", SoundCategory.MUSIC),
+    MOB_GUARDIAN_IDLE("mob.guardian.idle", "null", SoundCategory.HOSTILE),
+    RECORDS_WARD("records.ward", "record.ward", SoundCategory.RECORD),
+    RECORDS_13("records.13", "record.13", SoundCategory.RECORD),
+    MOB_RABBIT_HOP("mob.rabbit.hop", "entity.rabbit.jump", SoundCategory.NEUTRAL),
+    RECORDS_STRAD("records.strad", "record.strad", SoundCategory.RECORD),
+    RECORDS_11("records.11", "record.11", SoundCategory.RECORD),
+    RECORDS_MALL("records.mall", "record.mall", SoundCategory.RECORD),
+    RECORDS_BLOCKS("records.blocks", "record.blocks", SoundCategory.RECORD),
+    RECORDS_WAIT("records.wait", "record.wait", SoundCategory.RECORD),
+    MUSIC_GAME_END_CREDITS("music.game.end.credits", "music.credits", SoundCategory.MUSIC),
+    MUSIC_GAME_CREATIVE("music.game.creative", "music.creative", SoundCategory.MUSIC);
+
+    private final String name;
+    private final String newName;
+    private final SoundCategory category;
+    private final boolean breaksound;
+
+    SoundEffect(String name, String newname, SoundCategory cat) {
+        this.category = cat;
+        this.newName = newname;
+        this.name = name;
+        this.breaksound = name.startsWith("dig.");
+    }
+    
+    SoundEffect(String name, String newname, SoundCategory cat, boolean shouldIgnore) {
+        this.category = cat;
+        this.newName = newname;
+        this.name = name;
+        this.breaksound = name.startsWith("dig.") || shouldIgnore;
+    }
+
+    public static SoundEffect getByName(String name) {
+        name = name.toLowerCase();
+        for (SoundEffect e : SoundEffect.values()) {
+            if (e.getName().equals(name))
+                return e;
+        }
+        return null;
+    }
+
+}

src/main/java/us/myles/ViaVersion/transformers/IncomingTransformer.java

@@ -1,25 +1,27 @@
 package us.myles.ViaVersion.transformers;
 
 import io.netty.buffer.ByteBuf;
-import io.netty.channel.Channel;
+import io.netty.buffer.Unpooled;
+import org.bukkit.Material;
 import org.bukkit.inventory.ItemStack;
-import us.myles.ViaVersion.*;
-import us.myles.ViaVersion.handlers.ViaVersionInitializer;
+import us.myles.ViaVersion.CancelException;
+import us.myles.ViaVersion.ConnectionInfo;
+import us.myles.ViaVersion.ViaVersionPlugin;
+import us.myles.ViaVersion.api.ViaVersion;
 import us.myles.ViaVersion.packets.PacketType;
 import us.myles.ViaVersion.packets.State;
+import us.myles.ViaVersion.slot.ItemSlotRewriter;
+import us.myles.ViaVersion.util.PacketUtil;
 
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
+import java.io.IOException;
 
 public class IncomingTransformer {
-    private final Channel channel;
+    private final ViaVersionPlugin plugin = (ViaVersionPlugin) ViaVersion.getInstance();
     private final ConnectionInfo info;
-    private final ViaVersionInitializer init;
+    private boolean startedBlocking = false;
 
-    public IncomingTransformer(Channel channel, ConnectionInfo info, ViaVersionInitializer init) {
-        this.channel = channel;
+    public IncomingTransformer(ConnectionInfo info) {
         this.info = info;
-        this.init = init;
     }
 
     public void transform(int packetID, ByteBuf input, ByteBuf output) throws CancelException {
@@ -33,12 +35,19 @@ public class IncomingTransformer {
         if (packet.getPacketID() != -1) {
             packetID = packet.getPacketID();
         }
-//        if (packet != PacketType.PLAY_PLAYER_POSITION_LOOK_REQUEST && packet != PacketType.PLAY_KEEP_ALIVE_REQUEST && packet != PacketType.PLAY_PLAYER_POSITION_REQUEST && packet != PacketType.PLAY_PLAYER_LOOK_REQUEST) {
-//            System.out.println("Packet Type: " + packet + " New ID: " + packetID + " Original: " + original);
-//        }
-        if (packet == PacketType.PLAY_TP_CONFIRM) {
+        if (plugin.isDebug()) {
+            if (packet != PacketType.PLAY_PLAYER_POSITION_LOOK_REQUEST && packet != PacketType.PLAY_KEEP_ALIVE_REQUEST && packet != PacketType.PLAY_PLAYER_POSITION_REQUEST && packet != PacketType.PLAY_PLAYER_LOOK_REQUEST) {
+                System.out.println("Direction " + packet.getDirection().name() + " Packet Type: " + packet + " New ID: " + packetID + " Original: " + original + " Size: " + input.readableBytes());
+            }
+        }
+        if (packet == PacketType.PLAY_TP_CONFIRM || packet == PacketType.PLAY_VEHICLE_MOVE_REQUEST) { //TODO handle client-sided horse riding
             throw new CancelException();
         }
+        // Handle movement increment
+        // Update idle status (player, position, look, positionandlook)
+        if(packet == PacketType.PLAY_PLAYER || packet == PacketType.PLAY_PLAYER_POSITION_REQUEST || packet == PacketType.PLAY_PLAYER_LOOK_REQUEST || packet == PacketType.PLAY_PLAYER_POSITION_LOOK_REQUEST) {
+            info.incrementIdlePacket();
+        }
         PacketUtil.writeVarInt(packetID, output);
         if (packet == PacketType.HANDSHAKE) {
             int protVer = PacketUtil.readVarInt(input);
@@ -46,8 +55,8 @@ public class IncomingTransformer {
             PacketUtil.writeVarInt(protVer <= 102 ? protVer : 47, output); // pretend to be older
 
             if (protVer <= 102) {
-                // Not 1.9 remove pipes
-                this.init.remove();
+                // not 1.9, remove pipes
+                info.setActive(false);
             }
             String serverAddress = PacketUtil.readString(input);
             PacketUtil.writeString(serverAddress, output);
@@ -71,7 +80,7 @@ public class IncomingTransformer {
             output.writeLong(location);
             for (int i = 0; i < 4; i++) {
                 String line = PacketUtil.readString(input);
-                line = "{\"text\":\"" + line + "\"}";
+                line = OutgoingTransformer.fixJson(line);
                 PacketUtil.writeString(line, output);
             }
             return;
@@ -84,18 +93,31 @@ public class IncomingTransformer {
             return;
         }
         if (packet == PacketType.PLAY_PLAYER_DIGGING) {
-            byte status = input.readByte();
+            int status = input.readByte() & 0xFF; // unsign
+            if (status == 5 && startedBlocking) {
+                // stopped blocking
+                startedBlocking = false;
+                sendSecondHandItem(null);
+            }
             if (status == 6) { // item swap
                 throw new CancelException();
             }
             output.writeByte(status);
-            // read position
-            Long pos = input.readLong();
-            output.writeLong(pos);
-            short face = input.readUnsignedByte();
+            // write remaining bytes
+            Long position = input.readLong();
+            output.writeLong(position);
+
+            int face = input.readUnsignedByte();
             output.writeByte(face);
             return;
         }
+        if (packet == PacketType.PLAY_HELD_ITEM_CHANGE_REQUEST) {
+            if (startedBlocking) {
+                // stopped blocking
+                startedBlocking = false;
+                sendSecondHandItem(null);
+            }
+        }
         if (packet == PacketType.PLAY_CLICK_WINDOW) {
             // if placed in new slot, reject :)
             int windowID = input.readUnsignedByte();
@@ -103,32 +125,44 @@ public class IncomingTransformer {
 
             byte button = input.readByte();
             short action = input.readShort();
-            byte mode = input.readByte();
-            if (slot == 45 && windowID == 0) {
-                try {
-                    Class<?> setSlot = ReflectionUtil.nms("PacketPlayOutSetSlot");
-                    Object setSlotPacket = setSlot.getConstructors()[1].newInstance(windowID, slot, null);
-                    channel.writeAndFlush(setSlotPacket); // slot is empty
-                    slot = -999; // we're evil, they'll throw item on the ground
-                } catch (ClassNotFoundException e) {
-                    e.printStackTrace();
-                } catch (IllegalAccessException e) {
-                    e.printStackTrace();
-                } catch (InstantiationException e) {
-                    e.printStackTrace();
-                } catch (InvocationTargetException e) {
-                    e.printStackTrace();
-                }
+            int mode = input.readByte();
 
+            // if the action is on an elytra armour slot
+            boolean throwItem = (slot == 45 && windowID == 0);
+
+            if (info.getOpenWindow() != null && windowID > 0) {
+                if (info.getOpenWindow().equals("minecraft:brewing_stand")) {
+                    if (slot == 4) {
+                        // throw
+                        throwItem = true;
+                    }
+                    if (slot > 4)
+                        slot = (short) (slot - 1);
+                }
+            }
+            if (throwItem) {
+                ByteBuf buf = info.getChannel().alloc().buffer();
+                PacketUtil.writeVarInt(PacketType.PLAY_SET_SLOT.getNewPacketID(), buf);
+                buf.writeByte(windowID);
+                buf.writeShort(slot);
+                buf.writeShort(-1); // empty
+                info.sendRawPacket(buf);
+                // Continue the packet simulating throw
+                mode = 0;
+                button = 0;
+                slot = -999;
             }
             output.writeByte(windowID);
             output.writeShort(slot);
             output.writeByte(button);
             output.writeShort(action);
             output.writeByte(mode);
-            output.writeBytes(input);
+            ItemSlotRewriter.rewrite1_9To1_8(input, output);
             return;
         }
+        if (packet == PacketType.PLAY_CLOSE_WINDOW_REQUEST) {
+            info.closeWindow();
+        }
         if (packet == PacketType.PLAY_CLIENT_SETTINGS) {
             String locale = PacketUtil.readString(input);
             PacketUtil.writeString(locale, output);
@@ -152,6 +186,19 @@ public class IncomingTransformer {
             PacketUtil.readVarInt(input);
             return;
         }
+        if (packet == PacketType.PLAY_ENTITY_ACTION) {
+            int playerId = PacketUtil.readVarInt(input);
+            int action = PacketUtil.readVarInt(input);
+            int jump = PacketUtil.readVarInt(input);
+            if (action == 6 || action == 8) //Ignore stop jumping / start elytra flying
+                throw new CancelException();
+            if (action == 7) //Change open horse inventory to the 1.8 value
+                action = 6;
+            PacketUtil.writeVarInt(playerId, output);
+            PacketUtil.writeVarInt(action, output);
+            PacketUtil.writeVarInt(jump, output);
+            return;
+        }
         if (packet == PacketType.PLAY_USE_ENTITY) {
             int target = PacketUtil.readVarInt(input);
             PacketUtil.writeVarInt(target, output);
@@ -171,52 +218,135 @@ public class IncomingTransformer {
             }
             return;
         }
+        if (packet == PacketType.PLAY_PLUGIN_MESSAGE_REQUEST) {
+            String name = PacketUtil.readString(input);
+            PacketUtil.writeString(name, output);
+            byte[] b = new byte[input.readableBytes()];
+            input.readBytes(b);
+            // patch books
+            switch (name) {
+                case "MC|BSign": {
+                    ByteBuf in = Unpooled.wrappedBuffer(b);
+                    try {
+                        ItemSlotRewriter.ItemStack stack = ItemSlotRewriter.readItemStack(in);
+                        if (stack != null)
+                            stack.id = (short) Material.WRITTEN_BOOK.getId();
+                        // write
+                        ItemSlotRewriter.writeItemStack(stack, output);
+                    } catch (IOException e) {
+                        e.printStackTrace();
+                    }
+                    return;
+                }
+                case "MC|AutoCmd": {
+                    ByteBuf in = Unpooled.wrappedBuffer(b);
+                    int x = in.readInt();
+                    int y = in.readInt();
+                    int z = in.readInt();
+                    String command = PacketUtil.readString(in);
+                    boolean flag = in.readBoolean();
+
+                    output.clear();
+                    PacketUtil.writeVarInt(PacketType.PLAY_PLUGIN_MESSAGE_REQUEST.getPacketID(), output);
+                    PacketUtil.writeString("MC|AdvCdm", output);
+                    output.writeByte(0);
+                    output.writeInt(x);
+                    output.writeInt(y);
+                    output.writeInt(z);
+                    PacketUtil.writeString(command, output);
+                    output.writeBoolean(flag);
+                    return;
+                }
+                case "MC|AdvCmd":
+                    output.clear();
+                    PacketUtil.writeVarInt(PacketType.PLAY_PLUGIN_MESSAGE_REQUEST.getPacketID(), output);
+                    PacketUtil.writeString("MC|AdvCdm", output);
+                    output.writeBytes(b);
+                    break;
+            }
+            output.writeBytes(b);
+        }
         if (packet == PacketType.PLAY_PLAYER_BLOCK_PLACEMENT) {
             Long position = input.readLong();
             output.writeLong(position);
             int face = PacketUtil.readVarInt(input);
             output.writeByte(face);
-            int hand = PacketUtil.readVarInt(input);
+            PacketUtil.readVarInt(input);
 
-            ItemStack inHand = Core.getHandItem(info);
-            Object item = null;
+            ItemStack inHand = plugin.getHandItem(info);
             try {
-                Method m = ReflectionUtil.obc("inventory.CraftItemStack").getDeclaredMethod("asNMSCopy", ItemStack.class);
-                item = m.invoke(null, inHand);
-            } catch (NoSuchMethodException e) {
-                e.printStackTrace();
-            } catch (ClassNotFoundException e) {
-                e.printStackTrace();
-            } catch (InvocationTargetException e) {
-                e.printStackTrace();
-            } catch (IllegalAccessException e) {
+                ItemSlotRewriter.ItemStack item = ItemSlotRewriter.ItemStack.fromBukkit(inHand);
+                ItemSlotRewriter.fixIdsFrom1_9To1_8(item);
+                ItemSlotRewriter.writeItemStack(item, output);
+            } catch (Exception e) {
                 e.printStackTrace();
             }
-
-            PacketUtil.writeItem(item, output);
-
-            short curX = input.readUnsignedByte();
-            output.writeByte(curX);
-            short curY = input.readUnsignedByte();
-            output.writeByte(curY);
-            short curZ = input.readUnsignedByte();
-            output.writeByte(curZ);
-            return;
+	        short curX = input.readUnsignedByte();
+	        output.writeByte(curX);
+	        short curY = input.readUnsignedByte();
+	        output.writeByte(curY);
+	        short curZ = input.readUnsignedByte();
+	        output.writeByte(curZ);
+	        return;
         }
         if (packet == PacketType.PLAY_USE_ITEM) {
+            int hand = PacketUtil.readVarInt(input);
             output.clear();
             PacketUtil.writeVarInt(PacketType.PLAY_PLAYER_BLOCK_PLACEMENT.getPacketID(), output);
             // Simulate using item :)
             output.writeLong(-1L);
-            output.writeByte(-1);
+            output.writeByte(255);
             // write item in hand
-            output.writeShort(-1);
+            ItemStack inHand = plugin.getHandItem(info);
+            if (inHand != null && plugin.isShieldBlocking()) {
+                if (inHand.getType().name().endsWith("SWORD")) {
+                    // blocking?
+                    if (hand == 0) {
+                        if (!startedBlocking) {
+                            startedBlocking = true;
+                            ItemSlotRewriter.ItemStack shield = new ItemSlotRewriter.ItemStack();
+                            shield.id = 442;
+                            shield.amount = 1;
+                            shield.data = 0;
+                            sendSecondHandItem(shield);
+                        }
+                        throw new CancelException();
+                    }
+                }
+            }
+            try {
+                ItemSlotRewriter.ItemStack item = ItemSlotRewriter.ItemStack.fromBukkit(inHand);
+                ItemSlotRewriter.fixIdsFrom1_9To1_8(item);
+                ItemSlotRewriter.writeItemStack(item, output);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
 
-            output.writeByte(-1);
-            output.writeByte(-1);
-            output.writeByte(-1);
+            output.writeByte(0); //Is zero in 1.8, not -1
+            output.writeByte(0);
+            output.writeByte(0);
             return;
         }
+        if (packet == PacketType.PLAY_CREATIVE_INVENTORY_ACTION) {
+            short slot = input.readShort();
+            output.writeShort(slot);
+
+            ItemSlotRewriter.rewrite1_9To1_8(input, output);
+        }
         output.writeBytes(input);
     }
+
+    private void sendSecondHandItem(ItemSlotRewriter.ItemStack o) {
+        ByteBuf buf = info.getChannel().alloc().buffer();
+        PacketUtil.writeVarInt(PacketType.PLAY_ENTITY_EQUIPMENT.getNewPacketID(), buf);
+        PacketUtil.writeVarInt(info.getEntityID(), buf);
+        PacketUtil.writeVarInt(1, buf); // slot
+        // write shield
+        try {
+            ItemSlotRewriter.writeItemStack(o, buf);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        info.sendRawPacket(buf);
+    }
 }

src/main/java/us/myles/ViaVersion/update/UpdateListener.java

@@ -0,0 +1,22 @@
+package us.myles.ViaVersion.update;
+
+import lombok.RequiredArgsConstructor;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.plugin.Plugin;
+
+@RequiredArgsConstructor
+public class UpdateListener implements Listener {
+
+	private final Plugin plugin;
+	
+	@EventHandler
+	public void onJoin(PlayerJoinEvent e) {
+		if(e.getPlayer().hasPermission("viaversion.update")
+				&& plugin.getConfig().getBoolean("checkforupdates", true)) {
+			UpdateUtil.sendUpdateMessage(e.getPlayer().getUniqueId(), plugin);
+		}
+	}
+
+}

src/main/java/us/myles/ViaVersion/update/UpdateUtil.java

@@ -0,0 +1,125 @@
+package us.myles.ViaVersion.update;
+
+import org.bukkit.Bukkit;
+import org.bukkit.ChatColor;
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.scheduler.BukkitRunnable;
+import org.json.simple.JSONObject;
+import org.json.simple.parser.JSONParser;
+import org.json.simple.parser.ParseException;
+import us.myles.ViaVersion.api.ViaVersion;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.UUID;
+
+public class UpdateUtil {
+
+    private final static String URL = "http://api.spiget.org/v1/resources/";
+    private final static int PLUGIN = 19254;
+
+    public final static String PREFIX = ChatColor.GREEN + "" + ChatColor.BOLD + "[ViaVersion] " + ChatColor.GREEN;
+
+    public static void sendUpdateMessage(final UUID uuid, final Plugin plugin) {
+        new BukkitRunnable() {
+
+            @Override
+            public void run() {
+                final String message = getUpdateMessage(false);
+                if (message != null) {
+                    new BukkitRunnable() {
+
+                        @Override
+                        public void run() {
+                            Player p = Bukkit.getPlayer(uuid);
+                            if (p != null) {
+                                p.sendMessage(PREFIX + message);
+                            }
+                        }
+                    }.runTask(plugin);
+                }
+            }
+        }.runTaskAsynchronously(plugin);
+    }
+
+    public static void sendUpdateMessage(final Plugin plugin) {
+        new BukkitRunnable() {
+
+            @Override
+            public void run() {
+                final String message = getUpdateMessage(true);
+                if (message != null) {
+                    new BukkitRunnable() {
+
+                        @Override
+                        public void run() {
+                            plugin.getLogger().warning(message);
+                        }
+                    }.runTask(plugin);
+                }
+            }
+        }.runTaskAsynchronously(plugin);
+    }
+
+    private static String getUpdateMessage(boolean console) {
+        if (ViaVersion.getInstance().getVersion().equals("${project.version}")) {
+            return "You are using a debug/custom version, consider updating.";
+        }
+        String newestString = getNewestVersion();
+        if (newestString == null) {
+            if (console) {
+                return "Could not check for updates, check your connection.";
+            } else {
+                return null;
+            }
+        }
+        Version current;
+        try {
+            current = new Version(ViaVersion.getInstance().getVersion());
+        } catch (IllegalArgumentException e) {
+            return "You are using a debug/custom version, consider updating.";
+        }
+        Version newest = new Version(newestString);
+        if (current.compareTo(newest) < 0)
+            return "There is a newer version available: " + newest.toString();
+        else if (console && current.compareTo(newest) != 0) {
+            return "You are running a newer version than is released!";
+        }
+        return null;
+    }
+
+    private static String getNewestVersion() {
+        try {
+            URL url = new URL(URL + PLUGIN + "?" + System.currentTimeMillis());
+            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+            connection.setUseCaches(true);
+            connection.addRequestProperty("User-Agent", "ViaVersion " + ViaVersion.getInstance().getVersion());
+            connection.setDoOutput(true);
+            BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
+            String input;
+            String content = "";
+            while ((input = br.readLine()) != null) {
+                content = content + input;
+            }
+            br.close();
+            JSONParser parser = new JSONParser();
+            JSONObject statistics;
+            try {
+                statistics = (JSONObject) parser.parse(content);
+            } catch (ParseException e) {
+                e.printStackTrace();
+                return null;
+            }
+            return (String) statistics.get("version");
+        } catch (MalformedURLException e) {
+            return null;
+        } catch (IOException e) {
+            return null;
+        }
+    }
+}

src/main/java/us/myles/ViaVersion/update/Version.java

@@ -0,0 +1,62 @@
+package us.myles.ViaVersion.update;
+
+import org.apache.commons.lang.StringUtils;
+
+public class Version implements Comparable<Version> {
+    private int[] parts;
+
+    public Version(String value) {
+        if (value == null)
+            throw new IllegalArgumentException("Version can not be null");
+
+        if (!value.matches("^[0-9]+(\\.[0-9]+)*$"))
+            throw new IllegalArgumentException("Invalid version format");
+
+        String[] split = value.split("\\.");
+        parts = new int[split.length];
+
+        for (int i = 0; i < split.length; i += 1)
+            parts[i] = Integer.parseInt(split[i]);
+    }
+
+    public static int compare(Version verA, Version verB) {
+        if (verA == verB) return 0;
+        if (verA == null) return -1;
+        if (verB == null) return 1;
+
+        int max = Math.max(verA.parts.length, verB.parts.length);
+
+        for (int i = 0; i < max; i += 1) {
+            int partA = i < verA.parts.length ? verA.parts[i] : 0;
+            int partB = i < verB.parts.length ? verB.parts[i] : 0;
+            if (partA < partB) return -1;
+            if (partA > partB) return 1;
+        }
+
+        return 0;
+    }
+
+    public static boolean equals(Version verA, Version verB) {
+        return verA == verB || verA != null && verB != null && compare(verA, verB) == 0;
+    }
+
+    @Override
+    public String toString() {
+        String[] split = new String[parts.length];
+
+        for (int i = 0; i < parts.length; i += 1)
+            split[i] = String.valueOf(parts[i]);
+
+        return StringUtils.join(split, ".");
+    }
+
+    @Override
+    public int compareTo(Version that) {
+        return compare(this, that);
+    }
+
+    @Override
+    public boolean equals(Object that) {
+        return that instanceof Version && equals(this, (Version) that);
+    }
+}

src/main/java/us/myles/ViaVersion/util/Configuration.java

@@ -0,0 +1,246 @@
+package us.myles.ViaVersion.util;
+
+import com.google.common.base.Joiner;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import org.bukkit.Bukkit;
+import org.bukkit.configuration.InvalidConfigurationException;
+import org.bukkit.configuration.file.YamlConfiguration;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Level;
+import java.util.regex.Pattern;
+
+public class Configuration extends YamlConfiguration {
+    private List<String> mainHeader = Lists.newArrayList();
+    private final Map<String, List<String>> headers = Maps.newConcurrentMap();
+    private final File file;
+    private boolean loadHeaders;
+
+    public Configuration(File file) {
+        this.file = file;
+    }
+
+    /**
+     * Set the main header displayed at top of config.
+     *
+     * @param header header
+     */
+    public void mainHeader(String... header) {
+        mainHeader = Arrays.asList(header);
+    }
+
+    /**
+     * Get main header displayed at top of config.
+     *
+     * @return header
+     */
+    public List<String> mainHeader() {
+        return mainHeader;
+    }
+
+    /**
+     * Set option header.
+     *
+     * @param key of option (or section)
+     * @param header of option (or section)
+     */
+    public void header(String key, String... header) {
+//        String value = Joiner.on('\n').join(header);
+        headers.put(key, Arrays.asList(header));
+    }
+
+    /**
+     * Get header of option
+     *
+     * @param key of option (or section)
+     * @return Header
+     */
+    public List<String> header(String key) {
+        return headers.get(key);
+    }
+
+    public <T> T get(String key, Class<T> type) {
+        return type.cast(get(key));
+    }
+
+    /**
+     * Reload config from file.
+     */
+    public void reload() {
+        reload(headers.isEmpty());
+    }
+
+    /**
+     * Reload config from file.
+     *
+     * @param loadHeaders Whether or not to load headers.
+     */
+    public void reload(boolean loadHeaders) {
+        this.loadHeaders = loadHeaders;
+        try {
+            load(file);
+        } catch(Exception e) {
+            Bukkit.getLogger().log(Level.WARNING, "failed to reload file", e);
+        }
+    }
+
+    @Override
+    public void loadFromString(String contents) throws InvalidConfigurationException {
+        if(!loadHeaders) {
+            super.loadFromString(contents);
+            return;
+        }
+
+        StringBuilder memoryData = new StringBuilder();
+
+        // Parse headers
+        final int indentLength = options().indent();
+        final String pathSeparator = Character.toString(options().pathSeparator());
+        int currentIndents = 0;
+        String key = "";
+        List<String> headers = Lists.newArrayList();
+        for(String line : contents.split("\n")) {
+            if(line.isEmpty()) continue; // Skip empty lines
+            int indent = getSuccessiveCharCount(line, ' ');
+            String subline = indent > 0 ? line.substring(indent) : line;
+            if(subline.startsWith("#")) {
+                if(subline.startsWith("#>")) {
+                    String txt = subline.startsWith("#> ") ? subline.substring(3) : subline.substring(2);
+                    mainHeader.add(txt);
+                    continue; // Main header, handled by bukkit
+                }
+
+                // Add header to list
+                String txt = subline.startsWith("# ") ? subline.substring(2) : subline.substring(1);
+                headers.add(txt);
+                continue;
+            }
+
+            int indents = indent / indentLength;
+            if(indents <= currentIndents) {
+                // Remove last section of key
+                String[] array = key.split(Pattern.quote(pathSeparator));
+                int backspace = currentIndents - indents + 1;
+                key = join(array, options().pathSeparator(), 0, array.length - backspace);
+            }
+
+            // Add new section to key
+            String separator = key.length() > 0 ? pathSeparator : "";
+            String lineKey = line.contains(":") ? line.split(Pattern.quote(":"))[0] : line;
+            key += separator + lineKey.substring(indent);
+
+            currentIndents = indents;
+
+            memoryData.append(line).append('\n');
+            if(!headers.isEmpty()) {
+                this.headers.put(key, headers);
+                headers = Lists.newArrayList();
+            }
+        }
+
+        // Parse remaining text
+        super.loadFromString(memoryData.toString());
+
+        // Clear bukkit header
+        options().header(null);
+    }
+
+    /**
+     * Save config to file
+     */
+    public void save() {
+        if(headers.isEmpty() && mainHeader.isEmpty()) {
+            try {
+                super.save(file);
+            } catch(IOException e) {
+                Bukkit.getLogger().log(Level.WARNING, "Failed to save file", e);
+            }
+            return;
+        }
+
+        // Custom save
+        final int indentLength = options().indent();
+        final String pathSeparator = Character.toString(options().pathSeparator());
+        String content = saveToString();
+        StringBuilder fileData = new StringBuilder(buildHeader());
+        int currentIndents = 0;
+        String key = "";
+        for(String h : mainHeader) {
+            // Append main header to top of file
+            fileData.append("#> ").append(h).append('\n');
+        }
+
+        for(String line : content.split("\n")) {
+            if(line.isEmpty()) continue; // Skip empty lines
+            int indent = getSuccessiveCharCount(line, ' ');
+            int indents = indent / indentLength;
+            String indentText = indent > 0 ? line.substring(0, indent) : "";
+            if(indents <= currentIndents) {
+                // Remove last section of key
+                String[] array = key.split(Pattern.quote(pathSeparator));
+                int backspace = currentIndents - indents + 1;
+                key = join(array, options().pathSeparator(), 0, array.length - backspace);
+            }
+
+            // Add new section to key
+            String separator = key.length() > 0 ? pathSeparator : "";
+            String lineKey = line.contains(":") ? line.split(Pattern.quote(":"))[0] : line;
+            key += separator + lineKey.substring(indent);
+
+            currentIndents = indents;
+
+            List<String> header = headers.get(key);
+            String headerText = header != null ? addHeaderTags(header, indentText) : "";
+            fileData.append(headerText).append(line).append('\n');
+        }
+
+        // Write data to file
+        FileWriter writer = null;
+        try {
+            writer = new FileWriter(file);
+            writer.write(fileData.toString());
+            writer.flush();
+        } catch(IOException e) {
+            Bukkit.getLogger().log(Level.WARNING, "Failed to save file", e);
+        } finally {
+            if(writer != null) {
+                try {
+                    writer.close();
+                } catch(IOException e) {
+                }
+            }
+        }
+    }
+
+    private String addHeaderTags(List<String> header, String indent) {
+        StringBuilder builder = new StringBuilder();
+        for(String line : header) {
+            builder.append(indent).append("# ").append(line).append('\n');
+        }
+        return builder.toString();
+    }
+
+    private String join(String[] array, char joinChar, int start, int length) {
+        String[] copy = new String[length - start];
+        System.arraycopy(array, start, copy, 0, length - start);
+        return Joiner.on(joinChar).join(copy);
+    }
+
+    private int getSuccessiveCharCount(String text, char key) {
+        int count = 0;
+        for(int i = 0; i < text.length(); i++) {
+            if(text.charAt(i) == key) {
+                count += 1;
+            } else {
+                break;
+            }
+        }
+        return count;
+    }
+}

src/main/java/us/myles/ViaVersion/util/EntityUtil.java

@@ -0,0 +1,92 @@
+package us.myles.ViaVersion.util;
+
+import org.bukkit.entity.EntityType;
+
+public class EntityUtil {
+
+    public static EntityType getTypeFromID(int typeID, boolean isObject) {
+        if (isObject) {
+            return getObjectFromID(typeID);
+        } else {
+            return EntityType.fromId(typeID);
+        }
+    }
+
+    // based on http://wiki.vg/index.php?title=Entities
+    public static EntityType getObjectFromID(int objectID) {
+        EntityType type;
+        switch (objectID) {
+            case 2:
+                type = EntityType.DROPPED_ITEM;
+                break;
+            case 77:
+                type = EntityType.LEASH_HITCH;
+                break;
+            case 60:
+                type = EntityType.ARROW;
+                break;
+            case 61:
+                type = EntityType.SNOWBALL;
+                break;
+            case 63:
+                type = EntityType.FIREBALL;
+                break;
+            case 64:
+                type = EntityType.SMALL_FIREBALL;
+                break;
+            case 65:
+                type = EntityType.ENDER_PEARL;
+                break;
+            case 72:
+                type = EntityType.ENDER_SIGNAL;
+                break;
+            case 75:
+                type = EntityType.THROWN_EXP_BOTTLE;
+                break;
+            case 71:
+                type = EntityType.ITEM_FRAME;
+                break;
+            case 66:
+                type = EntityType.WITHER_SKULL;
+                break;
+            case 50:
+                type = EntityType.PRIMED_TNT;
+                break;
+            case 70:
+                type = EntityType.FALLING_BLOCK;
+                break;
+            case 76:
+                type = EntityType.FIREWORK;
+                break;
+            case 78:
+                type = EntityType.ARMOR_STAND;
+                break;
+            case 1:
+                type = EntityType.BOAT;
+                break;
+            case 10:
+                type = EntityType.MINECART;
+                break;
+            case 51:
+                type = EntityType.ENDER_CRYSTAL;
+                break;
+            case 73:
+                type = EntityType.SPLASH_POTION;
+                break;
+            case 62:
+                type = EntityType.EGG;
+                break;
+            case 90:
+                type = EntityType.FISHING_HOOK;
+                break;
+            default:
+                type = EntityType.fromId(objectID);
+                if (type == null) {
+                    System.out.println("Unable to find entity type for " + objectID);
+                    type = EntityType.UNKNOWN;
+                }
+                break;
+        }
+        return type;
+    }
+}

src/main/java/us/myles/ViaVersion/util/ListWrapper.java

@@ -0,0 +1,138 @@
+package us.myles.ViaVersion.util;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+import java.util.ListIterator;
+
+public abstract class ListWrapper implements List {
+    private final List list;
+
+    public ListWrapper(List inputList) {
+        this.list = inputList;
+    }
+
+    public abstract void handleAdd(Object o);
+
+    @Override
+    public synchronized int size() {
+        return this.list.size();
+    }
+
+    @Override
+    public synchronized boolean isEmpty() {
+        return this.list.isEmpty();
+    }
+
+    @Override
+    public synchronized boolean contains(Object o) {
+        return this.list.contains(o);
+    }
+
+    @Override
+    public synchronized Iterator iterator() {
+        return this.list.iterator();
+    }
+
+    @Override
+    public synchronized Object[] toArray() {
+        return this.list.toArray();
+    }
+
+    @Override
+    public synchronized boolean add(Object o) {
+        handleAdd(o);
+        return this.list.add(o);
+    }
+
+    @Override
+    public synchronized boolean remove(Object o) {
+        return this.list.remove(o);
+    }
+
+    @Override
+    public synchronized boolean addAll(Collection c) {
+        for (Object o : c) {
+            handleAdd(o);
+        }
+        return this.list.addAll(c);
+    }
+
+    @Override
+    public synchronized boolean addAll(int index, Collection c) {
+        for (Object o : c) {
+            handleAdd(o);
+        }
+        return this.list.addAll(index, c);
+    }
+
+    @Override
+    public synchronized void clear() {
+        this.list.clear();
+    }
+
+    @Override
+    public synchronized Object get(int index) {
+        return this.list.get(index);
+    }
+
+    @Override
+    public synchronized Object set(int index, Object element) {
+        return this.list.set(index, element);
+    }
+
+    @Override
+    public synchronized void add(int index, Object element) {
+        this.list.add(index, element);
+    }
+
+    @Override
+    public synchronized Object remove(int index) {
+        return this.list.remove(index);
+    }
+
+    @Override
+    public synchronized int indexOf(Object o) {
+        return this.list.indexOf(o);
+    }
+
+    @Override
+    public synchronized int lastIndexOf(Object o) {
+        return this.list.lastIndexOf(o);
+    }
+
+    @Override
+    public synchronized ListIterator listIterator() {
+        return this.list.listIterator();
+    }
+
+    @Override
+    public synchronized ListIterator listIterator(int index) {
+        return this.list.listIterator(index);
+    }
+
+    @Override
+    public synchronized List subList(int fromIndex, int toIndex) {
+        return this.list.subList(fromIndex, toIndex);
+    }
+
+    @Override
+    public synchronized boolean retainAll(Collection c) {
+        return this.list.retainAll(c);
+    }
+
+    @Override
+    public synchronized boolean removeAll(Collection c) {
+        return this.list.removeAll(c);
+    }
+
+    @Override
+    public synchronized boolean containsAll(Collection c) {
+        return this.list.containsAll(c);
+    }
+
+    @Override
+    public synchronized Object[] toArray(Object[] a) {
+        return this.list.toArray(a);
+    }
+}

src/main/java/us/myles/ViaVersion/util/PacketUtil.java

@@ -1,23 +1,22 @@
-package us.myles.ViaVersion;
+package us.myles.ViaVersion.util;
 
 import com.google.common.base.Charsets;
 import com.google.common.base.Preconditions;
 import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufInputStream;
+import io.netty.buffer.ByteBufOutputStream;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.ByteToMessageDecoder;
 import io.netty.handler.codec.MessageToByteEncoder;
-import us.myles.ViaVersion.chunks.MagicBitSet;
-import us.myles.ViaVersion.chunks.PacketChunk;
-import us.myles.ViaVersion.chunks.PacketChunkData;
+import org.spacehq.opennbt.NBTIO;
+import org.spacehq.opennbt.tag.builtin.CompoundTag;
 
-import java.io.ByteArrayOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
-import java.nio.ShortBuffer;
 import java.util.ArrayList;
-import java.util.BitSet;
 import java.util.List;
 import java.util.UUID;
 
@@ -42,29 +41,67 @@ public class PacketUtil {
         }
     }
 
-    public static ByteBuf decompress(ChannelHandlerContext ctx, ByteBuf msg) {
-        ByteToMessageDecoder x = (ByteToMessageDecoder) ctx.pipeline().get("decompress");
-        List<Object> output = new ArrayList<Object>();
+    public static CompoundTag readNBT(ByteBuf input) throws IOException {
+        // Default client is limited to 2097152 bytes. (2.09mb)
+        Preconditions.checkArgument(input.readableBytes() <= 2097152, "Cannot read NBT (got %s bytes)", input.readableBytes());
+
+        int readerIndex = input.readerIndex();
+        byte b = input.readByte();
+        if (b == 0) {
+            return null;
+        } else {
+            input.readerIndex(readerIndex);
+            ByteBufInputStream bytebufStream = new ByteBufInputStream(input);
+            DataInputStream dataInputStream = new DataInputStream(bytebufStream);
+            try {
+                return (CompoundTag) NBTIO.readTag(dataInputStream);
+            } finally {
+                dataInputStream.close();
+            }
+        }
+    }
+
+    public static void writeNBT(ByteBuf output, CompoundTag tag) throws IOException {
+        if (tag == null) {
+            output.writeByte(0);
+        } else {
+            ByteBufOutputStream bytebufStream = new ByteBufOutputStream(output);
+            DataOutputStream dataOutputStream = new DataOutputStream(bytebufStream);
+
+            NBTIO.writeTag(dataOutputStream, tag);
+
+            dataOutputStream.close();
+        }
+    }
+
+    public static List<Object> callDecode(ByteToMessageDecoder decoder, ChannelHandlerContext ctx, Object input) {
+        List<Object> output = new ArrayList<>();
         try {
-            PacketUtil.DECODE_METHOD.invoke(x, ctx, msg, output);
-        } catch (IllegalAccessException e) {
-            e.printStackTrace();
-        } catch (InvocationTargetException e) {
+            PacketUtil.DECODE_METHOD.invoke(decoder, ctx, input, output);
+        } catch (IllegalAccessException | InvocationTargetException e) {
             e.printStackTrace();
         }
+        return output;
+    }
+
+    public static void callEncode(MessageToByteEncoder encoder, ChannelHandlerContext ctx, Object msg, ByteBuf output) {
+        try {
+            PacketUtil.ENCODE_METHOD.invoke(encoder, ctx, msg, output);
+        } catch (IllegalAccessException | InvocationTargetException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static ByteBuf decompress(ChannelHandlerContext ctx, ByteBuf msg) {
+        ByteToMessageDecoder x = (ByteToMessageDecoder) ctx.pipeline().get("decompress");
+        List<Object> output = callDecode(x, ctx, msg);
         return output.size() == 0 ? null : (ByteBuf) output.get(0);
     }
 
     public static ByteBuf compress(ChannelHandlerContext ctx, ByteBuf msg) {
         MessageToByteEncoder x = (MessageToByteEncoder) ctx.pipeline().get("compress");
         ByteBuf output = ctx.alloc().buffer();
-        try {
-            PacketUtil.ENCODE_METHOD.invoke(x, ctx, msg, output);
-        } catch (IllegalAccessException e) {
-            e.printStackTrace();
-        } catch (InvocationTargetException e) {
-            e.printStackTrace();
-        }
+        callEncode(x, ctx, msg, output);
         return output;
     }
 
@@ -134,7 +171,7 @@ public class PacketUtil {
 
     public static List<String> readStringArray(ByteBuf buf) {
         int len = readVarInt(buf);
-        List<String> ret = new ArrayList<String>(len);
+        List<String> ret = new ArrayList<>(len);
         for (int i = 0; i < len; i++) {
             ret.add(readString(buf));
         }
@@ -184,6 +221,13 @@ public class PacketUtil {
         }
     }
 
+    public static void writeVarIntArray(List<Integer> integers, ByteBuf output) {
+        writeVarInt(integers.size(), output);
+        for (Integer i : integers) {
+            writeVarInt(i, output);
+        }
+    }
+
     public static int readVarShort(ByteBuf buf) {
         int low = buf.readUnsignedShort();
         int high = 0;
@@ -216,8 +260,8 @@ public class PacketUtil {
     }
 
     public static void writeLongs(long[] data, ByteBuf output) {
-        for (int index = 0; index < data.length; index++) {
-            output.writeLong(data[index]);
+        for (long aData : data) {
+            output.writeLong(aData);
         }
     }
 
@@ -230,130 +274,34 @@ public class PacketUtil {
         return data;
     }
 
-    // This method is based on one from here
-    // https://github.com/Steveice10/MCProtocolLib/blob/master/src/main/java/org/spacehq/mc/protocol/util/NetUtil.java
-    public static PacketChunk readChunkData(boolean isFullChunk, int bitmask, byte[] input) {
-        PacketChunkData[] chunks = new PacketChunkData[16];
-        boolean sky = false;
-        int expected = 0;
-        int position = 0;
-        ShortBuffer blockData = ByteBuffer.wrap(input).order(ByteOrder.LITTLE_ENDIAN).asShortBuffer();
-
-        for (int i = 0; i < chunks.length; i++) {
-            if ((bitmask & 1 << i) != 0) {
-                expected += (4096 * 2) + 2048;
-            }
-        }
-        // If there is more data, then there must be skylights :D
-        if (input.length > expected) {
-            sky = true;
-        }
-
-        // Read block data
-        for (int i = 0; i < chunks.length; i++) {
-            if ((bitmask & 1 << i) != 0) {
-                chunks[i] = new PacketChunkData(sky);
-                blockData.position(position / 2);
-                blockData.get(chunks[i].getBlocks(), 0, 4096);
-                position = position + (4096 * 2);
-            } else {
-                chunks[i] = new PacketChunkData(sky);
-            }
-        }
-        // Read blocklight data
-        for (int i = 0; i < chunks.length; i++) {
-            if ((bitmask & 1 << i) != 0) {
-                System.arraycopy(input, position, chunks[i].getBlockLight(), 0, 2048);
-                position = position + 2048;
-            }
-        }
-        // Read skylight data
-        if (sky) {
-            for (int i = 0; i < chunks.length; i++) {
-                if ((bitmask & 1 << i) != 0) {
-                    System.arraycopy(input, position, chunks[i].getSkyLight(), 0, 2048);
-                    position = position + 2048;
-                }
-            }
-        }
-
-        byte[] biomeData = null;
-
-        if (isFullChunk) {
-            // yay im a full chunk meaning i know my biomes, mommy get the camera!
-            biomeData = new byte[256];
-            System.arraycopy(input, position, biomeData, 0, 256);
-        }
-        return new PacketChunk(chunks, biomeData);
+    public static long[] readBlockPosition(ByteBuf buf) {
+        long val = buf.readLong();
+        long x = (val >> 38); // signed
+        long y = (val >> 26) & 0xfff; // unsigned
+        // this shifting madness is used to preserve sign
+        long z = (val << 38) >> 38; // signed
+        return new long[]{x, y, z};
     }
 
-    public static void writeNewChunk(ByteBuf buffer, PacketChunkData chunk) {
-        // Bits Per Block (We use 0, cause we're not gonna write a palette ;) )
-        buffer.writeByte(0);
-        // No Palette nor length :D
-
-        // Data Array Length
-        byte[] blockData = convertBlockArray(chunk.getBlocks());
-        writeVarInt(blockData.length / 8, buffer); // Notchian is divide by 8
-
-        buffer.writeBytes(blockData);
-        // Block Light
-        buffer.writeBytes(chunk.getBlockLight());
-        // If has skylight, write it
-        if (chunk.getSkyLight() != null) {
-            buffer.writeBytes(chunk.getSkyLight());
-        }
+    public static void writeBlockPosition(ByteBuf buf, long x, long y, long z) {
+        buf.writeLong(((x & 0x3ffffff) << 38) | ((y & 0xfff) << 26) | (z & 0x3ffffff));
     }
 
-    private static byte[] convertBlockArray(short[] blocks) {
-        //  block ID for the first 9 bits, and the block damage value for the last 4 bits
-        byte[] output = new byte[6664]; // (16 * 16 * 16 * 13) / 8 :) (plus some for padding ...)
-        ByteArrayOutputStream out = new ByteArrayOutputStream();
-        for (short block : blocks) {
-            int blockID = block >> 4; // (Needs to be to 9 bits)
-            int data = block & 0xF; // 8 bits
-
+    public static int[] readVarInts(int amount, ByteBuf input) {
+        int data[] = new int[amount];
+        for (int index = 0; index < amount; index++) {
+            data[index] = PacketUtil.readVarInt(input);
         }
-        return null; // todo: finish
+
+        return data;
     }
 
-    private static BitSet append(BitSet base, int index, MagicBitSet toAdd) {
-        int length = index;
-        for (int i = 0; i < toAdd.getTrueLength(); i++) {
-            base.set(length + i, toAdd.get(i));
-        }
-        return base;
-    }
-
-    private static MagicBitSet getPaddedBitSet(int value, int bitSize) {
-        MagicBitSet output = new MagicBitSet(bitSize);
-        BitSet temp = BitSet.valueOf(new long[]{value});
-        for (int i = 0; i < bitSize; i++) {
-            output.set(i, false);
-        }
-        int toShift = bitSize - temp.length();
-        for (int i = 0; i < temp.length(); i++) {
-            output.set(toShift + i, temp.get(i));
-        }
-        return output;
-    }
-
-    public static void writeItem(Object value, ByteBuf output) {
-        try {
-            Class<?> serializer = ReflectionUtil.nms("PacketDataSerializer");
-            Object init = serializer.getDeclaredConstructor(ByteBuf.class).newInstance(output);
-            Method toCall = init.getClass().getDeclaredMethod("a", ReflectionUtil.nms("ItemStack"));
-            toCall.invoke(init, value);
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
-        } catch (NoSuchMethodException e) {
-            e.printStackTrace();
-        } catch (InstantiationException e) {
-            e.printStackTrace();
-        } catch (IllegalAccessException e) {
-            e.printStackTrace();
-        } catch (InvocationTargetException e) {
-            e.printStackTrace();
+    public static boolean containsCause(Throwable t, Class<? extends Throwable> c) {
+        while (t != null) {
+            t = t.getCause();
+            if (t != null)
+                if (c.isAssignableFrom(t.getClass())) return true;
         }
+        return false;
     }
 }

src/main/java/us/myles/ViaVersion/util/ReflectionUtil.java

@@ -0,0 +1,127 @@
+package us.myles.ViaVersion.util;
+
+import com.google.common.collect.Maps;
+import org.bukkit.Bukkit;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+
+public class ReflectionUtil {
+    private static String BASE = Bukkit.getServer().getClass().getPackage().getName();
+    private static String NMS = BASE.replace("org.bukkit.craftbukkit", "net.minecraft.server");
+
+    public static Class<?> nms(String className) throws ClassNotFoundException {
+        return Class.forName(NMS + "." + className);
+    }
+    public static Class<?> obc(String className) throws ClassNotFoundException {
+        return Class.forName(BASE + "." + className);
+    }
+
+    public static Object invokeStatic(Class<?> clazz, String method) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
+        Method m = clazz.getDeclaredMethod(method);
+        return m.invoke(null);
+    }
+
+    public static Object invoke(Object o, String method) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
+        Method m = o.getClass().getDeclaredMethod(method);
+        return m.invoke(o);
+    }
+
+    public static <T> T getStatic(Class<?> clazz, String f, Class<T> t) throws NoSuchFieldException, IllegalAccessException {
+        Field field = clazz.getDeclaredField(f);
+        field.setAccessible(true);
+        return (T) field.get(null);
+    }
+
+    public static <T> T get(Object instance, Class<?> clazz, String f, Class<T> t) throws NoSuchFieldException, IllegalAccessException {
+        Field field = clazz.getDeclaredField(f);
+        field.setAccessible(true);
+        return (T) field.get(instance);
+    }
+
+    public static <T> T get(Object o, String f, Class<T> t) throws NoSuchFieldException, IllegalAccessException {
+        Field field = o.getClass().getDeclaredField(f);
+        field.setAccessible(true);
+        return (T) field.get(o);
+    }
+
+    public static void set(Object o, String f, Object value) throws NoSuchFieldException, IllegalAccessException {
+        Field field = o.getClass().getDeclaredField(f);
+        field.setAccessible(true);
+        field.set(o, value);
+    }
+
+    public static final class ClassReflection {
+        private final Class<?> handle;
+        private final Map<String, Field> fields = Maps.newConcurrentMap();
+        private final Map<String, Method> methods = Maps.newConcurrentMap();
+
+        public ClassReflection(Class<?> handle) {
+            this(handle, true);
+        }
+
+        public ClassReflection(Class<?> handle, boolean recursive) {
+            this.handle = handle;
+            scanFields(handle, recursive);
+            scanMethods(handle, recursive);
+        }
+
+        private void scanFields(Class<?> host, boolean recursive) {
+            if(host.getSuperclass() != null && recursive) {
+                scanFields(host.getSuperclass(), true);
+            }
+
+            for(Field field : host.getDeclaredFields()) {
+                field.setAccessible(true);
+                fields.put(field.getName(), field);
+            }
+        }
+
+        private void scanMethods(Class<?> host, boolean recursive) {
+            if(host.getSuperclass() != null && recursive) {
+                scanMethods(host.getSuperclass(), true);
+            }
+
+            for(Method method : host.getDeclaredMethods()) {
+                method.setAccessible(true);
+                methods.put(method.getName(), method);
+            }
+        }
+
+        public Object newInstance() throws IllegalAccessException, InstantiationException {
+            return handle.newInstance();
+        }
+
+        public Field getField(String name) {
+            return fields.get(name);
+        }
+
+        public void setFieldValue(String fieldName, Object instance, Object value) throws IllegalAccessException {
+            getField(fieldName).set(instance, value);
+        }
+
+        public <T> T getFieldValue(String fieldName, Object instance, Class<T> type) throws IllegalAccessException {
+            return type.cast(getField(fieldName).get(instance));
+        }
+
+        public <T> T invokeMethod(Class<T> type, String methodName, Object instance, Object... args) throws InvocationTargetException, IllegalAccessException {
+            return type.cast(getMethod(methodName).invoke(instance, args));
+        }
+
+        public Method getMethod(String name) {
+            return methods.get(name);
+        }
+
+        public Collection<Field> getFields() {
+            return Collections.unmodifiableCollection(fields.values());
+        }
+
+        public Collection<Method> getMethods() {
+            return Collections.unmodifiableCollection(methods.values());
+        }
+    }
+}

src/main/resources/config.yml

@@ -0,0 +1,22 @@
+# Should ViaVersion check for updates?
+checkforupdates: true
+# No collide options, these allow you to configure how collision works.
+# Do you want us to prevent collision?
+prevent-collision: true
+# If the above is true, should we automatically team players until you do?
+auto-team: true
+# When enabled if certain metadata can't be read we won't tell you about it
+suppress-metadata-errors: false
+# When enabled 1.9 will be able to block by using shields
+shield-blocking: true
+# Should we enable our hologram patch?
+# If they're in the wrong place enable this
+hologram-patch: false
+# This is the offset, should work as default when enabled.
+hologram-y: -1
+# Enable player tick simulation, this fixes eating, drinking, nether portals.
+simulate-pt: true
+# Should we patch boss bars so they work? (Default: true, disable if you're having issues)
+bossbar-patch: true
+# If your boss bar flickers on 1.9, set this to 'true'. It will keep all boss bars on 100% (not recommended)
+bossbar-anti-flicker: false

src/main/resources/plugin.yml

@@ -1,4 +1,11 @@
 name: ViaVersion
-main: us.myles.ViaVersion.Core
+main: us.myles.ViaVersion.ViaVersionPlugin
 author: _MylesC
-version: 0.3.1
+version: ${project.version}
+load: startup
+loadbefore: [ProtocolLib, ProxyPipe]
+commands:
+  viaversion:
+    description: Shows ViaVersion Version and more.
+    permission: viaversion.admin
+    aliases: [viaver]