Use reflection for VanillaCommandListener

Moved error handling to the wrapper
Fixed commands on Discord getting executed even if the preprocess event got cancelled

src/main/java/buttondevteam/discordplugin/DiscordConnectedPlayer.java

@@ -67,13 +67,7 @@ public abstract class DiscordConnectedPlayer extends DiscordSenderBase implement
 		this.module = module;
 		uniqueId = uuid;
 		displayName = mcname;
-		try {
 		vanillaCmdListener = new VCMDWrapper(VCMDWrapper.createListener(this));
-			if (vanillaCmdListener.getListener() == null)
-				DPUtils.getLogger().warning("Vanilla commands won't be available from Discord due to a compatibility error.");
-		} catch (NoClassDefFoundError e) {
-			DPUtils.getLogger().warning("Vanilla commands won't be available from Discord due to a compatibility error.");
-		}
 	}
 
 	/**

src/main/java/buttondevteam/discordplugin/DiscordPlayerSender.java

@@ -17,13 +17,7 @@ public abstract class DiscordPlayerSender extends DiscordSenderBase implements I
 	public DiscordPlayerSender(User user, MessageChannel channel, Player player) {
 		super(user, channel);
 		this.player = player;
-		try {
 		vanillaCmdListener = new VCMDWrapper(VCMDWrapper.createListener(this, player));
-			if (vanillaCmdListener.getListener() == null)
-				DPUtils.getLogger().warning("Vanilla commands won't be available from Discord due to a compatibility error.");
-		} catch (NoClassDefFoundError e) {
-			DPUtils.getLogger().warning("Vanilla commands won't be available from Discord due to a compatibility error.");
-		}
 	}
 
 	@Override

src/main/java/buttondevteam/discordplugin/mcchat/MCChatListener.java

@@ -6,6 +6,7 @@ import buttondevteam.discordplugin.listeners.CommandListener;
 import buttondevteam.discordplugin.listeners.CommonListeners;
 import buttondevteam.discordplugin.playerfaker.VanillaCommandListener;
 import buttondevteam.discordplugin.playerfaker.VanillaCommandListener14;
+import buttondevteam.discordplugin.playerfaker.VanillaCommandListener15;
 import buttondevteam.discordplugin.util.Timings;
 import buttondevteam.lib.*;
 import buttondevteam.lib.chat.ChatMessage;
@@ -361,27 +362,31 @@ public class MCChatListener implements Listener {
 				+ "ou can access all of your regular commands (even offline) in private chat: DM me `mcchat`!");
 			return true;
 		}
+		Bukkit.getLogger().info(dsender.getName() + " issued command from Discord: /" + cmd);
 		val channel = clmd == null ? user.channel().get() : clmd.mcchannel;
 		val ev = new TBMCCommandPreprocessEvent(dsender, channel, dmessage, clmd == null ? dsender : clmd.dcp);
-		Bukkit.getScheduler().runTask(DiscordPlugin.plugin, () -> Bukkit.getPluginManager().callEvent(ev));
-		if (ev.isCancelled())
-			return true;
 		Bukkit.getScheduler().runTask(DiscordPlugin.plugin, //Commands need to be run sync
 			() -> {
+				Bukkit.getPluginManager().callEvent(ev);
+				if (ev.isCancelled())
+					return;
 				try {
 					String mcpackage = Bukkit.getServer().getClass().getPackage().getName();
 					if (mcpackage.contains("1_12"))
 						VanillaCommandListener.runBukkitOrVanillaCommand(dsender, cmd);
-					else if (mcpackage.contains("1_14") || mcpackage.contains("1_15"))
+					else if (mcpackage.contains("1_14"))
 						VanillaCommandListener14.runBukkitOrVanillaCommand(dsender, cmd);
+					else if (mcpackage.contains("1_15"))
+						VanillaCommandListener15.runBukkitOrVanillaCommand(dsender, cmd);
 					else
 						Bukkit.dispatchCommand(dsender, cmd);
 				} catch (NoClassDefFoundError e) {
 					TBMCCoreAPI.SendException("A class is not found when trying to run command " + cmd + "!", e);
+				} catch (Exception e) {
+					TBMCCoreAPI.SendException("An error occurred when trying to run command " + cmd + "!", e);
 				}
-				Bukkit.getLogger().info(dsender.getName() + " issued command from Discord: /" + cmd);
 			});
-		return false;
+		return true;
 	}
 
 	@FunctionalInterface

src/main/java/buttondevteam/discordplugin/playerfaker/VCMDWrapper.java

@@ -1,5 +1,6 @@
 package buttondevteam.discordplugin.playerfaker;
 
+import buttondevteam.discordplugin.DPUtils;
 import buttondevteam.discordplugin.DiscordSenderBase;
 import buttondevteam.discordplugin.IMCPlayer;
 import lombok.Getter;
@@ -28,12 +29,29 @@ public class VCMDWrapper {
 	 * @param bukkitplayer The Bukkit player to send the raw message to
 	 */
 	public static <T extends DiscordSenderBase & IMCPlayer<T>> Object createListener(T player, Player bukkitplayer) {
+		try {
+			Object ret;
 			String mcpackage = Bukkit.getServer().getClass().getPackage().getName();
 			if (mcpackage.contains("1_12"))
-			return bukkitplayer == null ? new VanillaCommandListener<>(player) : new VanillaCommandListener<>(player, bukkitplayer);
+				ret = new VanillaCommandListener<>(player, bukkitplayer);
-		else if (mcpackage.contains("1_14") || mcpackage.contains("1_15"))
+			else if (mcpackage.contains("1_14"))
-			return bukkitplayer == null ? new VanillaCommandListener14<>(player) : new VanillaCommandListener14<>(player, bukkitplayer);
+				ret = new VanillaCommandListener14<>(player, bukkitplayer);
+			else if (mcpackage.contains("1_15"))
+				ret = VanillaCommandListener15.create(player, bukkitplayer); //bukkitplayer may be null but that's fine
 			else
+				ret = null;
+			if (ret == null)
+				compatWarning();
+			return ret;
+		} catch (NoClassDefFoundError | Exception e) {
+			compatWarning();
+			if (!(e instanceof NoClassDefFoundError))
+				e.printStackTrace();
 			return null;
 		}
 	}
+
+	private static void compatWarning() {
+		DPUtils.getLogger().warning("Vanilla commands won't be available from Discord due to a compatibility error.");
+	}
+}

src/main/java/buttondevteam/discordplugin/playerfaker/VanillaCommandListener15.java

@@ -0,0 +1,136 @@
+package buttondevteam.discordplugin.playerfaker;
+
+import buttondevteam.discordplugin.DiscordSenderBase;
+import buttondevteam.discordplugin.IMCPlayer;
+import lombok.Getter;
+import lombok.val;
+import org.bukkit.Bukkit;
+import org.bukkit.command.CommandSender;
+import org.bukkit.command.SimpleCommandMap;
+import org.bukkit.entity.Player;
+import org.mockito.Answers;
+import org.mockito.Mockito;
+
+import java.lang.reflect.Modifier;
+import java.util.Arrays;
+
+/**
+ * Same as {@link VanillaCommandListener14} but with reflection
+ */
+public class VanillaCommandListener15<T extends DiscordSenderBase & IMCPlayer<T>> {
+	private @Getter T player;
+	private static Class<?> vcwcl;
+	private static String nms;
+
+	protected VanillaCommandListener15(T player, Player bukkitplayer) {
+		this.player = player;
+		if (bukkitplayer != null && !bukkitplayer.getClass().getSimpleName().endsWith("CraftPlayer"))
+			throw new ClassCastException("bukkitplayer must be a Bukkit player!");
+	}
+
+	/**
+	 * This method will only send raw vanilla messages to the sender in plain text.
+	 *
+	 * @param player The Discord sender player (the wrapper)
+	 */
+	public static <T extends DiscordSenderBase & IMCPlayer<T>> VanillaCommandListener15<T> create(T player) throws Exception {
+		return create(player, null);
+	}
+
+	/**
+	 * This method will send both raw vanilla messages to the sender in plain text and forward the raw message to the provided player.
+	 *
+	 * @param player       The Discord sender player (the wrapper)
+	 * @param bukkitplayer The Bukkit player to send the raw message to
+	 */
+	@SuppressWarnings("unchecked")
+	public static <T extends DiscordSenderBase & IMCPlayer<T>> VanillaCommandListener15<T> create(T player, Player bukkitplayer) throws Exception {
+		if (vcwcl == null) {
+			String pkg = Bukkit.getServer().getClass().getPackage().getName();
+			vcwcl = Class.forName(pkg + ".command.VanillaCommandWrapper");
+		}
+		if (nms == null) {
+			var server = Bukkit.getServer();
+			nms = server.getClass().getMethod("getServer").invoke(server).getClass().getPackage().getName(); //org.mockito.codegen
+		}
+		var iclcl = Class.forName(nms + ".ICommandListener");
+		return Mockito.mock(VanillaCommandListener15.class, Mockito.withSettings().stubOnly()
+			.useConstructor(player, bukkitplayer).extraInterfaces(iclcl).defaultAnswer(invocation -> {
+				if (invocation.getMethod().getName().equals("sendMessage")) {
+					var icbc = invocation.getArgument(0);
+					player.sendMessage((String) icbc.getClass().getMethod("getString").invoke(icbc));
+					if (bukkitplayer != null) {
+						var handle = bukkitplayer.getClass().getMethod("getHandle").invoke(bukkitplayer);
+						handle.getClass().getMethod("sendMessage", icbc.getClass()).invoke(handle, icbc);
+					}
+					return null;
+				}
+				if (!Modifier.isAbstract(invocation.getMethod().getModifiers()))
+					return invocation.callRealMethod();
+				if (invocation.getMethod().getReturnType() == boolean.class)
+					return true; //shouldSend... shouldBroadcast...
+				if (invocation.getMethod().getReturnType() == CommandSender.class)
+					return player;
+				return Answers.RETURNS_DEFAULTS.answer(invocation);
+			}));
+	}
+
+	public static boolean runBukkitOrVanillaCommand(DiscordSenderBase dsender, String cmdstr) throws Exception {
+		var server = Bukkit.getServer();
+		var cmap = (SimpleCommandMap) server.getClass().getMethod("getCommandMap").invoke(server);
+		val cmd = cmap.getCommand(cmdstr.split(" ")[0].toLowerCase());
+		if (!(dsender instanceof Player) || !vcwcl.isAssignableFrom(dsender.getClass()))
+			return Bukkit.dispatchCommand(dsender, cmdstr); // Unconnected users are treated well in vanilla cmds
+
+		if (!(dsender instanceof IMCPlayer))
+			throw new ClassCastException(
+				"dsender needs to implement IMCPlayer to use vanilla commands as it implements Player.");
+
+		IMCPlayer<?> sender = (IMCPlayer<?>) dsender; // Don't use val on recursive interfaces :P
+
+		if (!(Boolean) vcwcl.getMethod("testPermission", CommandSender.class).invoke(cmd, sender))
+			return true;
+
+		var cworld = Bukkit.getWorlds().get(0);
+		val world = cworld.getClass().getMethod("getHandle").invoke(cworld);
+		var icommandlistener = sender.getVanillaCmdListener().getListener();
+		var nms = icommandlistener.getClass().getPackage().getName();
+		var clwcl = Class.forName(nms + ".CommandListenerWrapper");
+		var v3dcl = Class.forName(nms + ".Vec3D");
+		var v2fcl = Class.forName(nms + ".Vec2F");
+		var icbcl = Class.forName(nms + ".IChatBaseComponent");
+		var mcscl = Class.forName(nms + ".MinecraftServer");
+		var ecl = Class.forName(nms + ".Entity");
+		var cctcl = Class.forName(nms + ".ChatComponentText");
+		Object wrapper = clwcl.getConstructor(icommandlistener.getClass(), v3dcl, v2fcl, world.getClass(), int.class, String.class, icbcl, mcscl, ecl)
+			.newInstance(icommandlistener,
+				v3dcl.getConstructor(double.class, double.class, double.class).newInstance(0, 0, 0),
+				v2fcl.getConstructor(float.class, float.class).newInstance(0, 0),
+				world, 0, sender.getName(), cctcl.getConstructor(String.class).newInstance(sender.getName()),
+				world.getClass().getMethod("getMinecraftServer").invoke(world), null);
+		/*val wrapper = new CommandListenerWrapper(icommandlistener, new Vec3D(0, 0, 0),
+			new Vec2F(0, 0), world, 0, sender.getName(),
+			new ChatComponentText(sender.getName()), world.getMinecraftServer(), null);*/
+		var pncscl = Class.forName(vcwcl.getPackage().getName() + ".ProxiedNativeCommandSender");
+		Object pncs = pncscl.getConstructor(clwcl, sender.getClass(), sender.getClass())
+			.newInstance(wrapper, sender, sender);
+		String[] args = cmdstr.split(" ");
+		args = Arrays.copyOfRange(args, 1, args.length);
+		try {
+			return cmd.execute((CommandSender) pncs, cmd.getLabel(), args);
+		} catch (Exception commandexception) {
+			if (!commandexception.getClass().getSimpleName().equals("CommandException"))
+				throw commandexception;
+			// Taken from CommandHandler
+			var cmcl = Class.forName(nms + ".ChatMessage");
+			var chatmessage = cmcl.getConstructor(String.class, Object[].class)
+				.newInstance(commandexception.getMessage(),
+					new Object[]{commandexception.getClass().getMethod("a").invoke(commandexception)});
+			var modifier = cmcl.getMethod("getChatModifier").invoke(chatmessage);
+			var ecfcl = Class.forName(nms + ".EnumChatFormat");
+			modifier.getClass().getMethod("setColor", ecfcl).invoke(modifier, ecfcl.getField("RED").get(null));
+			icommandlistener.getClass().getMethod("sendMessage", icbcl).invoke(icommandlistener, chatmessage);
+		}
+		return true;
+	}
+}