Implement new queue command system.

Fix cannot remove block currency with mvm set command.

pom.xml

@@ -215,7 +215,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-shade-plugin</artifactId>
-                <version>3.1.1</version>
+                <version>3.2.4</version>
                 <executions>
                     <execution>
                         <phase>package</phase>
@@ -264,13 +264,19 @@
             <plugin>
                 <groupId>se.eris</groupId>
                 <artifactId>notnull-instrumenter-maven-plugin</artifactId>
-                <version>0.6.8</version>
+                <version>1.0.0</version>
                 <executions>
                     <execution>
                         <goals>
                             <goal>instrument</goal>
                             <goal>tests-instrument</goal>
                         </goals>
+                        <configuration>
+                            <notNull>
+                                <param>org.jetbrains.annotations.NotNull</param>
+                                <param>javax.validation.constraints.NotNull</param>
+                            </notNull>
+                        </configuration>
                     </execution>
                 </executions>
             </plugin>
@@ -353,21 +359,21 @@
         <dependency>
             <groupId>org.powermock</groupId>
             <artifactId>powermock-module-junit4</artifactId>
-            <version>2.0.0</version>
+            <version>2.0.9</version>
             <type>jar</type>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>org.powermock</groupId>
             <artifactId>powermock-api-easymock</artifactId>
-            <version>2.0.0</version>
+            <version>2.0.9</version>
             <type>jar</type>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>org.powermock</groupId>
             <artifactId>powermock-api-mockito2</artifactId>
-            <version>2.0.0</version>
+            <version>2.0.9</version>
             <type>jar</type>
             <scope>test</scope>
         </dependency>

src/main/java/com/onarandombox/MultiverseCore/MultiverseCore.java

@@ -68,6 +68,7 @@ import com.onarandombox.MultiverseCore.commands.TeleportCommand;
 import com.onarandombox.MultiverseCore.commands.UnloadCommand;
 import com.onarandombox.MultiverseCore.commands.VersionCommand;
 import com.onarandombox.MultiverseCore.commands.WhoCommand;
+import com.onarandombox.MultiverseCore.commandtools.queue.CommandQueueManager;
 import com.onarandombox.MultiverseCore.destination.AnchorDestination;
 import com.onarandombox.MultiverseCore.destination.BedDestination;
 import com.onarandombox.MultiverseCore.destination.CannonDestination;
@@ -88,6 +89,7 @@ import com.onarandombox.MultiverseCore.listeners.MVWeatherListener;
 import com.onarandombox.MultiverseCore.listeners.MVWorldInitListener;
 import com.onarandombox.MultiverseCore.listeners.MVWorldListener;
 import com.onarandombox.MultiverseCore.utils.AnchorManager;
+import com.onarandombox.MultiverseCore.utils.CompatibilityLayer;
 import com.onarandombox.MultiverseCore.utils.MVEconomist;
 import com.onarandombox.MultiverseCore.utils.MVMessaging;
 import com.onarandombox.MultiverseCore.utils.MVPermissions;
@@ -203,6 +205,7 @@ public class MultiverseCore extends JavaPlugin implements MVPlugin, Core {
 
     // Setup our Map for our Commands using the CommandHandler.
     private CommandHandler commandHandler;
+    private CommandQueueManager commandQueueManager;
 
     private static final String LOG_TAG = "[Multiverse-Core]";
 
@@ -254,6 +257,8 @@ public class MultiverseCore extends JavaPlugin implements MVPlugin, Core {
         // Setup our SafeTTeleporter
         this.safeTTeleporter = new SimpleSafeTTeleporter(this);
         this.unsafeCallWrapper = new UnsafeCallWrapper(this);
+        // Setup our CompatibilityLayer
+        CompatibilityLayer.init();
     }
 
 
@@ -285,6 +290,7 @@ public class MultiverseCore extends JavaPlugin implements MVPlugin, Core {
 
         // Setup the command manager
         this.commandHandler = new CommandHandler(this, this.ph);
+        this.commandQueueManager = new CommandQueueManager(this);
         // Call the Function to assign all the Commands to their Class.
         this.registerCommands();
 
@@ -353,13 +359,16 @@ public class MultiverseCore extends JavaPlugin implements MVPlugin, Core {
      * Initializes the buscript javascript library.
      */
     private void initializeBuscript() {
-        try {
-            buscript = new Buscript(this);
-            // Add global variable "multiverse" to javascript environment
-            buscript.setScriptVariable("multiverse", this);
-        } catch (NullPointerException e) {
-            buscript = null;
-            Logging.warning("Buscript failed to load! The script command will be disabled!");
+        buscript = null;
+
+        if (this.getMVConfig().getEnableBuscript()) {
+            try {
+                buscript = new Buscript(this);
+                // Add global variable "multiverse" to javascript environment
+                buscript.setScriptVariable("multiverse", this);
+            } catch (NullPointerException e) {
+                Logging.warning("Buscript failed to load! The script command will be disabled!");
+            }
         }
     }
 
@@ -911,6 +920,15 @@ public class MultiverseCore extends JavaPlugin implements MVPlugin, Core {
         return this.commandHandler;
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    @Deprecated
+    public CommandQueueManager getCommandQueueManager() {
+        return commandQueueManager;
+    }
+
     /**
      * Gets the log-tag.
      *

src/main/java/com/onarandombox/MultiverseCore/MultiverseCoreConfiguration.java

@@ -56,6 +56,8 @@ public class MultiverseCoreConfiguration extends SerializationConfig implements
     @Property
     private volatile boolean displaypermerrors;
     @Property
+    private volatile boolean enablebuscript;
+    @Property
     private volatile int globaldebug;
     @Property
     private volatile boolean silentstart;
@@ -99,6 +101,7 @@ public class MultiverseCoreConfiguration extends SerializationConfig implements
         teleportintercept = true;
         firstspawnoverride = true;
         displaypermerrors = true;
+        enablebuscript = true;
         globaldebug = 0;
         messagecooldown = 5000;
         teleportcooldown = 1000;
@@ -213,6 +216,22 @@ public class MultiverseCoreConfiguration extends SerializationConfig implements
         return this.displaypermerrors;
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public boolean getEnableBuscript() {
+        return this.enablebuscript;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void setEnableBuscript(boolean enableBuscript) {
+        this.enablebuscript = enableBuscript;
+    }
+
     /**
      * {@inheritDoc}
      */

src/main/java/com/onarandombox/MultiverseCore/api/Core.java

@@ -8,6 +8,7 @@
 package com.onarandombox.MultiverseCore.api;
 
 import buscript.Buscript;
+import com.onarandombox.MultiverseCore.commandtools.queue.CommandQueueManager;
 import com.onarandombox.MultiverseCore.destination.DestinationFactory;
 import com.onarandombox.MultiverseCore.utils.AnchorManager;
 import com.onarandombox.MultiverseCore.utils.MVEconomist;
@@ -86,6 +87,15 @@ public interface Core {
      */
     CommandHandler getCommandHandler();
 
+    /**
+     * Manager for command that requires /mv confirm before execution.
+     *
+     * @return A non-null {@link CommandQueueManager}.
+     * @deprecated To be moved to new command manager in 5.0.0
+     */
+    @Deprecated
+    CommandQueueManager getCommandQueueManager();
+
     /**
      * Gets the factory class responsible for loading many different destinations
      * on demand.

src/main/java/com/onarandombox/MultiverseCore/api/MultiverseCoreConfig.java

@@ -86,6 +86,18 @@ public interface MultiverseCoreConfig extends ConfigurationSerializable {
      */
     boolean getDisplayPermErrors();
 
+    /**
+     * Sets enableBuscript.
+     * @param enableBuscript The new value.
+     */
+    void setEnableBuscript(boolean enableBuscript);
+
+    /**
+     * Gets enableBuscript.
+     * @return enableBuscript.
+     */
+    boolean getEnableBuscript();
+
     /**
      * Sets firstSpawnOverride.
      * @param firstSpawnOverride The new value.

src/main/java/com/onarandombox/MultiverseCore/commands/ConfirmCommand.java

@@ -33,7 +33,7 @@ public class ConfirmCommand extends MultiverseCommand {
 
     @Override
     public void runCommand(CommandSender sender, List<String> args) {
-        this.plugin.getCommandHandler().confirmQueuedCommand(sender);
+        this.plugin.getCommandQueueManager().runQueuedCommand(sender);
     }
 
 }

src/main/java/com/onarandombox/MultiverseCore/commands/DeleteCommand.java

@@ -8,9 +8,11 @@
 package com.onarandombox.MultiverseCore.commands;
 
 import com.onarandombox.MultiverseCore.MultiverseCore;
+import com.onarandombox.MultiverseCore.commandtools.queue.QueuedCommand;
 import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.permissions.PermissionDefault;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -35,11 +37,24 @@ public class DeleteCommand extends MultiverseCommand {
     public void runCommand(CommandSender sender, List<String> args) {
         String worldName = args.get(0);
 
-        Class<?>[] paramTypes = {String.class};
-        List<Object> objectArgs = new ArrayList<Object>(args);
-        this.plugin.getCommandHandler()
-                   .queueCommand(sender, "mvdelete", "deleteWorld", objectArgs,
-                                 paramTypes, ChatColor.GREEN + "World '" + worldName + "' Deleted!",
-                                 ChatColor.RED + "World '" + worldName + "' could NOT be deleted!");
+        this.plugin.getCommandQueueManager().addToQueue(new QueuedCommand(
+                sender,
+                deleteRunnable(sender, worldName),
+                String.format("Are you sure you want to delete world '%s'? You cannot undo this action.", worldName)
+        ));
+    }
+
+    private Runnable deleteRunnable(@NotNull CommandSender sender,
+                                    @NotNull String worldName) {
+
+        return () -> {
+            sender.sendMessage(String.format("Deleting world '%s'...", worldName));
+            if (this.plugin.getMVWorldManager().deleteWorld(worldName)) {
+                sender.sendMessage(String.format("%sWorld %s was deleted!", ChatColor.GREEN, worldName));
+                return;
+            }
+            sender.sendMessage(String.format("%sThere was an issue deleting '%s'! Please check console for errors.",
+                    ChatColor.RED, worldName));
+        };
     }
 }

src/main/java/com/onarandombox/MultiverseCore/commands/InfoCommand.java

@@ -115,6 +115,7 @@ public class InfoCommand extends MultiverseCommand {
         FancyColorScheme colors = new FancyColorScheme(ChatColor.AQUA, ChatColor.AQUA, ChatColor.GOLD, ChatColor.WHITE);
         message.add(new FancyHeader("General Info", colors));
         message.add(new FancyMessage("World Name: ", world.getName(), colors));
+        message.add(new FancyMessage("World UID: ", world.getCBWorld().getUID().toString(), colors));
         message.add(new FancyMessage("World Alias: ", world.getColoredWorldString(), colors));
         message.add(new FancyMessage("Game Mode: ", world.getGameMode().toString(), colors));
         message.add(new FancyMessage("Difficulty: ", world.getDifficulty().toString(), colors));
@@ -151,6 +152,7 @@ public class InfoCommand extends MultiverseCommand {
         message = new ArrayList<FancyText>();
         message.add(new FancyHeader("More World Settings", colors));
         message.add(new FancyMessage("World Type: ", world.getWorldType().toString(), colors));
+        message.add(new FancyMessage("Generator: ", world.getGenerator(), colors));
         message.add(new FancyMessage("Structures: ", world.getCBWorld().canGenerateStructures() + "", colors));
         message.add(new FancyMessage("Weather: ", world.isWeatherEnabled() + "", colors));
         message.add(new FancyMessage("Players will get hungry: ", world.getHunger() + "", colors));

src/main/java/com/onarandombox/MultiverseCore/commands/RegenCommand.java

@@ -8,9 +8,11 @@
 package com.onarandombox.MultiverseCore.commands;
 
 import com.onarandombox.MultiverseCore.MultiverseCore;
+import com.onarandombox.MultiverseCore.commandtools.queue.QueuedCommand;
 import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.permissions.PermissionDefault;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -37,17 +39,30 @@ public class RegenCommand extends MultiverseCommand {
 
     @Override
     public void runCommand(CommandSender sender, List<String> args) {
-        Boolean useseed = (!(args.size() == 1));
-        Boolean randomseed = (args.size() == 2 && args.get(1).equalsIgnoreCase("-s"));
+        String worldName = args.get(0);
+        boolean useseed = (!(args.size() == 1));
+        boolean randomseed = (args.size() == 2 && args.get(1).equalsIgnoreCase("-s"));
         String seed = (args.size() == 3) ? args.get(2) : "";
 
-        Class<?>[] paramTypes = {String.class, Boolean.class, Boolean.class, String.class};
-        List<Object> objectArgs = new ArrayList<Object>();
-        objectArgs.add(args.get(0));
-        objectArgs.add(useseed);
-        objectArgs.add(randomseed);
-        objectArgs.add(seed);
-        this.plugin.getCommandHandler().queueCommand(sender, "mvregen", "regenWorld", objectArgs,
-                paramTypes, ChatColor.GREEN + "World Regenerated!", ChatColor.RED + "World could NOT be regenerated!");
+        this.plugin.getCommandQueueManager().addToQueue(new QueuedCommand(
+                sender,
+                doWorldRegen(sender, worldName, useseed, randomseed, seed),
+                String.format("Are you sure you want to regen '%s'? You cannot undo this action.", worldName)
+        ));
+    }
+
+    private Runnable doWorldRegen(@NotNull CommandSender sender,
+                                  @NotNull String worldName,
+                                  boolean useSeed,
+                                  boolean randomSeed,
+                                  @NotNull String seed) {
+
+        return () -> {
+            if (this.plugin.getMVWorldManager().regenWorld(worldName, useSeed, randomSeed, seed)) {
+                sender.sendMessage(ChatColor.GREEN + "World Regenerated!");
+                return;
+            }
+            sender.sendMessage(ChatColor.RED + "World could NOT be regenerated!");
+        };
     }
 }

src/main/java/com/onarandombox/MultiverseCore/commands/TeleportCommand.java

@@ -11,6 +11,7 @@ import com.dumptruckman.minecraft.util.Logging;
 import com.onarandombox.MultiverseCore.MultiverseCore;
 import com.onarandombox.MultiverseCore.api.Teleporter;
 import com.onarandombox.MultiverseCore.api.MVDestination;
+import com.onarandombox.MultiverseCore.commandtools.queue.QueuedCommand;
 import com.onarandombox.MultiverseCore.destination.CustomTeleporterDestination;
 import com.onarandombox.MultiverseCore.destination.DestinationFactory;
 import com.onarandombox.MultiverseCore.destination.InvalidDestination;
@@ -165,24 +166,27 @@ public class TeleportCommand extends MultiverseCommand {
         if (result == TeleportResult.FAIL_UNSAFE) {
             Logging.fine("Could not teleport " + teleportee.getName()
                     + " to " + plugin.getLocationManipulation().strCoordsRaw(d.getLocation(teleportee)));
-            Logging.fine("Queueing Command");
-            Class<?>[] paramTypes = { CommandSender.class, Player.class, Location.class };
-            List<Object> items = new ArrayList<Object>();
-            items.add(teleporter);
-            items.add(teleportee);
-            items.add(d.getLocation(teleportee));
+
             String player = "you";
             if (!teleportee.equals(teleporter)) {
                 player = teleportee.getName();
             }
-            String message = String.format("%sMultiverse %sdid not teleport %s%s %sto %s%s %sbecause it was unsafe.",
-                    ChatColor.GREEN, ChatColor.WHITE, ChatColor.AQUA, player, ChatColor.WHITE, ChatColor.DARK_AQUA, d.getName(), ChatColor.WHITE);
-            this.plugin.getCommandHandler().queueCommand(sender, "mvteleport", "teleportPlayer", items,
-                    paramTypes, message, "Would you like to try anyway?", "", "", UNSAFE_TELEPORT_EXPIRE_DELAY);
+
+            this.plugin.getCommandQueueManager().addToQueue(new QueuedCommand(
+                    sender,
+                    doUnsafeTeleport(teleporter, teleportee, d.getLocation(teleportee)),
+                    String.format("%sMultiverse %sdid not teleport %s%s %sto %s%s %sbecause it was unsafe. Would you like to try anyway?",
+                            ChatColor.GREEN, ChatColor.WHITE, ChatColor.AQUA, player, ChatColor.WHITE, ChatColor.DARK_AQUA, d.getName(), ChatColor.WHITE),
+                    UNSAFE_TELEPORT_EXPIRE_DELAY
+            ));
         }
         // else: Player was teleported successfully (or the tp event was fired I should say)
     }
 
+    private Runnable doUnsafeTeleport(CommandSender teleporter, Player player, Location location) {
+        return () -> this.plugin.getSafeTTeleporter().safelyTeleport(teleporter, player, location, false);
+    }
+
     private boolean checkSendPermissions(CommandSender teleporter, Player teleportee, MVDestination destination) {
         if (teleporter.equals(teleportee)) {
             if (!this.plugin.getMVPerms().hasPermission(teleporter, "multiverse.teleport.self." + destination.getIdentifier(), true)) {

src/main/java/com/onarandombox/MultiverseCore/commands/VersionCommand.java

@@ -64,6 +64,7 @@ public class VersionCommand extends MultiverseCommand {
                 + "[Multiverse-Core]   teleportintercept: " + plugin.getMVConfig().getTeleportIntercept() + '\n'
                 + "[Multiverse-Core]   firstspawnoverride: " + plugin.getMVConfig().getFirstSpawnOverride() + '\n'
                 + "[Multiverse-Core]   displaypermerrors: " + plugin.getMVConfig().getDisplayPermErrors() + '\n'
+                + "[Multiverse-Core]   enablebuscript: " + plugin.getMVConfig().getEnableBuscript() + '\n'
                 + "[Multiverse-Core]   globaldebug: " + plugin.getMVConfig().getGlobalDebug() + '\n'
                 + "[Multiverse-Core]   silentstart: " + plugin.getMVConfig().getSilentStart() + '\n'
                 + "[Multiverse-Core]   messagecooldown: " + plugin.getMessaging().getCooldown() + '\n'

src/main/java/com/onarandombox/MultiverseCore/commandtools/queue/CommandQueueManager.java

@@ -0,0 +1,158 @@
+/******************************************************************************
+ * Multiverse 2 Copyright (c) the Multiverse Team 2020.                       *
+ * Multiverse 2 is licensed under the BSD License.                            *
+ * For more information please check the README.md file included              *
+ * with this project.                                                         *
+ ******************************************************************************/
+
+package com.onarandombox.MultiverseCore.commandtools.queue;
+
+import com.dumptruckman.minecraft.util.Logging;
+import com.onarandombox.MultiverseCore.MultiverseCore;
+import org.bukkit.Bukkit;
+import org.bukkit.ChatColor;
+import org.bukkit.block.data.type.CommandBlock;
+import org.bukkit.command.BlockCommandSender;
+import org.bukkit.command.CommandSender;
+import org.bukkit.scheduler.BukkitTask;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Map;
+import java.util.WeakHashMap;
+
+/**
+ * Managers the queuing of dangerous commands that needs to use '/mv confirm' before executing.
+ */
+public class CommandQueueManager {
+
+    private static final long TICKS_PER_SECOND = 20;
+    private static final DummyCommandBlockSender COMMAND_BLOCK = new DummyCommandBlockSender();
+
+    private final MultiverseCore plugin;
+    private final Map<CommandSender, QueuedCommand> queuedCommandMap;
+
+    public CommandQueueManager(@NotNull MultiverseCore plugin) {
+        this.plugin = plugin;
+        this.queuedCommandMap = new WeakHashMap<>();
+    }
+
+    /**
+     * Adds a queue command into queue.
+     *
+     * @param queuedCommand The queue command to add.
+     */
+    public void addToQueue(QueuedCommand queuedCommand) {
+        CommandSender targetSender = parseSender(queuedCommand.getSender());
+
+        // Since only one command is stored in queue per sender, we remove the old one.
+        this.removeFromQueue(targetSender);
+
+        Logging.finer("Add new command to queue for sender %s.", targetSender);
+        this.queuedCommandMap.put(targetSender, queuedCommand);
+        queuedCommand.setExpireTask(runExpireLater(queuedCommand));
+
+        queuedCommand.getSender().sendMessage(queuedCommand.getPrompt());
+        queuedCommand.getSender().sendMessage(String.format("Run %s/mv confirm %sto continue. This will expire in %s seconds.",
+                ChatColor.GREEN, ChatColor.WHITE, queuedCommand.getValidDuration()));
+    }
+
+    /**
+     * Expire task that remove {@link QueuedCommand} from queue after valid duration defined.
+     *
+     * @param queuedCommand Command to run the expire task on.
+     * @return The expire {@link BukkitTask}.
+     */
+    @NotNull
+    private BukkitTask runExpireLater(@NotNull QueuedCommand queuedCommand) {
+        return Bukkit.getScheduler().runTaskLater(
+                this.plugin,
+                expireRunnable(queuedCommand),
+                queuedCommand.getValidDuration() * TICKS_PER_SECOND
+        );
+    }
+
+    /**
+     * Runnable responsible for expiring the queued command.
+     *
+     * @param queuedCommand Command to create the expire task on.
+     * @return The expire runnable.
+     */
+    @NotNull
+    private Runnable expireRunnable(@NotNull QueuedCommand queuedCommand) {
+        return () -> {
+            CommandSender targetSender = parseSender(queuedCommand.getSender());
+            QueuedCommand matchingQueuedCommand = this.queuedCommandMap.get(targetSender);
+            if (!queuedCommand.equals(matchingQueuedCommand) || queuedCommand.getExpireTask().isCancelled()) {
+                // To be safe, but this shouldn't happen since we cancel old commands before add new once.
+                Logging.finer("This is an old queue command already.");
+                return;
+            }
+            queuedCommand.getSender().sendMessage("Your queued command has expired.");
+            this.queuedCommandMap.remove(queuedCommand.getSender());
+        };
+    }
+
+    /**
+     * Runs the command in queue for the given sender, if any.
+     *
+     * @param sender    {@link CommandSender} that confirmed the command.
+     * @return True if queued command ran successfully, else false.
+     */
+    public boolean runQueuedCommand(@NotNull CommandSender sender) {
+        CommandSender targetSender = parseSender(sender);
+        QueuedCommand queuedCommand = this.queuedCommandMap.get(targetSender);
+        if (queuedCommand == null) {
+            sender.sendMessage(ChatColor.RED + "You do not have any commands in queue.");
+            return false;
+        }
+        Logging.finer("Running queued command...");
+        queuedCommand.getAction().run();
+        return removeFromQueue(targetSender);
+    }
+
+    /**
+     * Since only one command is stored in queue per sender, we remove the old one.
+     *
+     * @param sender    The {@link CommandSender} that executed the command.
+     * @return True if queue command is removed from sender successfully, else false.
+     */
+    public boolean removeFromQueue(@NotNull CommandSender sender) {
+        CommandSender targetSender = parseSender(sender);
+        QueuedCommand previousCommand = this.queuedCommandMap.remove(targetSender);
+        if (previousCommand == null) {
+            Logging.finer("No queue command to remove for sender %s.", targetSender.getName());
+            return false;
+        }
+        previousCommand.getExpireTask().cancel();
+        Logging.finer("Removed queue command for sender %s.", targetSender.getName());
+        return true;
+    }
+
+    /**
+     * To allow all CommandBlocks to be a common sender with use of {@link DummyCommandBlockSender}.
+     * So confirm command can be used for a queue command on another command block.
+     *
+     * @param sender    The sender to parse.
+     * @return The sender, or if its a command block, a {@link DummyCommandBlockSender}.
+     */
+    @NotNull
+    private CommandSender parseSender(@NotNull CommandSender sender) {
+        Logging.fine(sender.getClass().getName());
+        if (isCommandBlock(sender)) {
+            Logging.finer("Is command block.");
+            return COMMAND_BLOCK;
+        }
+        return sender;
+    }
+
+    /**
+     * Check if sender is a command block.
+     *
+     * @param sender    The sender to check on.
+     * @return True if sender is a command block, else false.
+     */
+    private boolean isCommandBlock(@NotNull CommandSender sender) {
+        return sender instanceof BlockCommandSender
+                && ((BlockCommandSender) sender).getBlock().getBlockData() instanceof CommandBlock;
+    }
+}

src/main/java/com/onarandombox/MultiverseCore/commandtools/queue/DummyCommandBlockSender.java

@@ -0,0 +1,104 @@
+package com.onarandombox.MultiverseCore.commandtools.queue;
+
+import org.bukkit.Bukkit;
+import org.bukkit.Server;
+import org.bukkit.command.CommandSender;
+import org.bukkit.permissions.Permission;
+import org.bukkit.permissions.PermissionAttachment;
+import org.bukkit.permissions.PermissionAttachmentInfo;
+import org.bukkit.plugin.Plugin;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Set;
+
+/**
+ * Used by {@link CommandQueueManager}, so different commands block can be recognised as one.
+ */
+class DummyCommandBlockSender implements CommandSender {
+
+    @Override
+    public void sendMessage(@NotNull String message) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void sendMessage(@NotNull String[] messages) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public @NotNull Server getServer() {
+        return Bukkit.getServer();
+    }
+
+    @Override
+    public @NotNull String getName() {
+        return "DummyCommandBlockSender";
+    }
+
+    @Override
+    public boolean isPermissionSet(@NotNull String name) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean isPermissionSet(@NotNull Permission perm) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean hasPermission(@NotNull String name) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean hasPermission(@NotNull Permission perm) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public @NotNull PermissionAttachment addAttachment(@NotNull Plugin plugin, @NotNull String name, boolean value) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public @NotNull PermissionAttachment addAttachment(@NotNull Plugin plugin) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public @Nullable PermissionAttachment addAttachment(@NotNull Plugin plugin, @NotNull String name, boolean value, int ticks) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public @Nullable PermissionAttachment addAttachment(@NotNull Plugin plugin, int ticks) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void removeAttachment(@NotNull PermissionAttachment attachment) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void recalculatePermissions() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public @NotNull Set<PermissionAttachmentInfo> getEffectivePermissions() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean isOp() {
+        return true;
+    }
+
+    @Override
+    public void setOp(boolean value) {
+        throw new UnsupportedOperationException();
+    }
+}

src/main/java/com/onarandombox/MultiverseCore/commandtools/queue/QueuedCommand.java

@@ -0,0 +1,86 @@
+/******************************************************************************
+ * Multiverse 2 Copyright (c) the Multiverse Team 2020.                       *
+ * Multiverse 2 is licensed under the BSD License.                            *
+ * For more information please check the README.md file included              *
+ * with this project.                                                         *
+ ******************************************************************************/
+
+package com.onarandombox.MultiverseCore.commandtools.queue;
+
+import org.bukkit.command.CommandSender;
+import org.bukkit.scheduler.BukkitTask;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Represents a single command used in {@link CommandQueueManager} for confirming before running potentially
+ * dangerous action.
+ */
+public class QueuedCommand {
+
+    private static final String DEFAULT_PROMPT_MESSAGE = "The command you are trying to run is deemed dangerous.";
+    private static final int DEFAULT_VALID_TIME = 10;
+
+    private final CommandSender sender;
+    private final Runnable action;
+    private final String prompt;
+    private final int validDuration;
+    private BukkitTask expireTask;
+
+    public QueuedCommand(CommandSender sender, Runnable action) {
+        this(sender, action, DEFAULT_PROMPT_MESSAGE, DEFAULT_VALID_TIME);
+    }
+
+    public QueuedCommand(CommandSender sender, Runnable action, String prompt) {
+        this(sender, action, prompt, DEFAULT_VALID_TIME);
+    }
+
+    public QueuedCommand(CommandSender sender, Runnable action, int validDuration) {
+        this(sender, action, DEFAULT_PROMPT_MESSAGE, validDuration);
+    }
+
+    /**
+     * Creates a new queue command, to be registered at {@link CommandQueueManager#addToQueue(QueuedCommand)}.
+     *
+     * @param sender        The sender that ran the command needed for confirmation.
+     * @param action        The logic to execute upon confirming.
+     * @param prompt        Question to ask sender to confirm.
+     * @param validDuration Duration in which the command is valid for confirm in seconds.
+     */
+    public QueuedCommand(CommandSender sender, Runnable action, String prompt, int validDuration) {
+        this.sender = sender;
+        this.action = action;
+        this.prompt = prompt;
+        this.validDuration = validDuration;
+    }
+
+    @NotNull
+    CommandSender getSender() {
+        return sender;
+    }
+
+    @NotNull
+    String getPrompt() {
+        return prompt;
+    }
+
+    int getValidDuration() {
+        return validDuration;
+    }
+
+    @NotNull
+    Runnable getAction() {
+        return action;
+    }
+
+    @NotNull
+    BukkitTask getExpireTask() {
+        return expireTask;
+    }
+
+    void setExpireTask(@NotNull BukkitTask expireTask) {
+        if (this.expireTask != null) {
+            throw new IllegalStateException("This queue command already has an expire task. You can't register twice!");
+        }
+        this.expireTask = expireTask;
+    }
+}

src/main/java/com/onarandombox/MultiverseCore/commandtools/queue/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Manager queuing of dangerous commands in need of confirmation.
+ */
+package com.onarandombox.MultiverseCore.commandtools.queue;

src/main/java/com/onarandombox/MultiverseCore/configuration/EntryFee.java

@@ -22,6 +22,8 @@ public class EntryFee extends SerializationConfig {
     @Nullable
     private Material currency;
 
+    private final Material DISABLED_MATERIAL = Material.AIR;
+
     public EntryFee() {
         super();
     }
@@ -51,6 +53,9 @@ public class EntryFee extends SerializationConfig {
      */
     @Nullable
     public Material getCurrency() {
+        if (currency == null || currency.equals(DISABLED_MATERIAL)) {
+            return null;
+        }
         return currency;
     }
 

src/main/java/com/onarandombox/MultiverseCore/enums/RespawnType.java

@@ -0,0 +1,7 @@
+package com.onarandombox.MultiverseCore.enums;
+
+public enum RespawnType {
+    BED,
+    ANCHOR,
+    OTHER
+}

src/main/java/com/onarandombox/MultiverseCore/listeners/MVPlayerListener.java

@@ -15,7 +15,9 @@ import com.dumptruckman.minecraft.util.Logging;
 import com.onarandombox.MultiverseCore.MultiverseCore;
 import com.onarandombox.MultiverseCore.api.MVWorldManager;
 import com.onarandombox.MultiverseCore.api.MultiverseWorld;
+import com.onarandombox.MultiverseCore.enums.RespawnType;
 import com.onarandombox.MultiverseCore.event.MVRespawnEvent;
+import com.onarandombox.MultiverseCore.utils.CompatibilityLayer;
 import com.onarandombox.MultiverseCore.utils.PermissionTools;
 import org.bukkit.GameMode;
 import org.bukkit.Location;
@@ -69,9 +71,16 @@ public class MVPlayerListener implements Listener {
             return;
         }
 
+        RespawnType respawnType = RespawnType.OTHER;
+        if (event.isBedSpawn()) {
+            respawnType = RespawnType.BED;
+        }
+        if (CompatibilityLayer.isAnchorSpawn(event)) {
+            respawnType = RespawnType.ANCHOR;
+        }
 
-        if (mvWorld.getBedRespawn() && event.isBedSpawn()) {
-            Logging.fine("Spawning " + event.getPlayer().getName() + " at their bed");
+        if (mvWorld.getBedRespawn() && (respawnType == RespawnType.BED || respawnType == RespawnType.ANCHOR)) {
+            Logging.fine("Spawning %s at their %s", event.getPlayer().getName(), respawnType);
             return;
         }
 

src/main/java/com/onarandombox/MultiverseCore/utils/CompatibilityLayer.java

@@ -0,0 +1,46 @@
+package com.onarandombox.MultiverseCore.utils;
+
+import com.dumptruckman.minecraft.util.Logging;
+import org.bukkit.Bukkit;
+import org.bukkit.event.player.PlayerRespawnEvent;
+
+import java.lang.reflect.Method;
+
+/**
+ * A utility class to enable version specific minecraft features.
+ */
+public class CompatibilityLayer {
+
+    private static Method checkAnchorSpawn;
+
+    /**
+     * Initialise the reflection methods.
+     */
+    public static void init() {
+        try {
+            checkAnchorSpawn = PlayerRespawnEvent.class.getDeclaredMethod("isAnchorSpawn");
+        } catch (NoSuchMethodException e) {
+            Logging.fine("%s does not support respawn anchors.", Bukkit.getVersion());
+        }
+    }
+
+    /**
+     * Check if the respawn point is of respawn anchor type.
+     * Introduced in minecraft 1.16
+     *
+     * @param event A player respawn event.
+     * @return If the respawn location is an anchor point.
+     */
+    public static boolean isAnchorSpawn(PlayerRespawnEvent event) {
+        if (checkAnchorSpawn == null) {
+            return false;
+        }
+        try {
+            return (boolean) checkAnchorSpawn.invoke(event);
+        } catch (Exception e) {
+            Logging.warning("Error checking for: %s", checkAnchorSpawn);
+            e.printStackTrace();
+        }
+        return false;
+    }
+}

src/main/java/com/onarandombox/MultiverseCore/utils/SimpleLocationManipulation.java

@@ -40,6 +40,15 @@ public class SimpleLocationManipulation implements LocationManipulation {
         orientationInts.put("w", 90);
         orientationInts.put("nw", 135);
 
+        orientationInts.put("north", 180);
+        orientationInts.put("northeast", 225);
+        orientationInts.put("east", 270);
+        orientationInts.put("southeast", 315);
+        orientationInts.put("south", 0);
+        orientationInts.put("southwest", 45);
+        orientationInts.put("west", 90);
+        orientationInts.put("northwest", 135);
+
         // "freeze" the map:
         ORIENTATION_INTS = Collections.unmodifiableMap(orientationInts);
         // END CHECKSTYLE-SUPPRESSION: MagicNumberCheck

src/test/java/com/onarandombox/MultiverseCore/TestEntryFeeConversion.java

@@ -50,6 +50,10 @@ public class TestEntryFeeConversion {
         WorldProperties props = new WorldProperties(config);
         assertNull(props.entryfee.getCurrency());
 
+        entryFee.put("currency", 0);
+        props = new WorldProperties(config);
+        assertNull(props.entryfee.getCurrency());
+
         entryFee.put("currency", 1);
         props = new WorldProperties(config);
         assertEquals(Material.STONE, props.entryfee.getCurrency());

src/test/java/com/onarandombox/MultiverseCore/utils/TestInstanceCreator.java

@@ -214,11 +214,18 @@ public class TestInstanceCreator {
             serverfield.set(core, mockServer);
 
             // Set buscript
-            Buscript buscript = PowerMockito.spy(new Buscript(core));
+            Buscript buscript;
             Field buscriptfield = MultiverseCore.class.getDeclaredField("buscript");
             buscriptfield.setAccessible(true);
+
+            try {
+                buscript = PowerMockito.spy(new Buscript(core));
+                when(buscript.getPlugin()).thenReturn(core);
+            } catch (NullPointerException e) {
+                buscript = null;
+            }
+
             buscriptfield.set(core, buscript);
-            when(buscript.getPlugin()).thenReturn(core);
 
             // Set worldManager
             WorldManager wm = PowerMockito.spy(new WorldManager(core));