Fix tabcompletion: use custom suggestion provider

It looks like we can't have custom argument types
Checking for permission for each offered option
Suggesting the argument's name as well
#82

TODO:
Handle annotations
Remove test command

Chroma-Core/src/main/java/buttondevteam/core/ChromaCommand.java

@@ -26,7 +26,7 @@ public class ChromaCommand extends ICommand2MC {
 		sender.sendMessage(ButtonPlugin.getCommand2MC().getCommandsText());
 	}
 
-	@Command2.Subcommand
+	@Command2.Subcommand //TODO: Remove
 	public void test(CommandSender sender, char test) {
 		sender.sendMessage(test + "");
 	}

Chroma-Core/src/main/java/buttondevteam/core/ComponentCommand.java

@@ -6,13 +6,17 @@ import buttondevteam.lib.architecture.Component;
 import buttondevteam.lib.chat.Command2;
 import buttondevteam.lib.chat.Command2.Subcommand;
 import buttondevteam.lib.chat.CommandClass;
+import buttondevteam.lib.chat.CustomTabCompleteMethod;
 import buttondevteam.lib.chat.ICommand2MC;
 import lombok.val;
 import org.bukkit.Bukkit;
 import org.bukkit.command.CommandSender;
 import org.bukkit.plugin.Plugin;
+import org.bukkit.plugin.java.JavaPlugin;
 
+import java.util.Arrays;
 import java.util.Optional;
+import java.util.stream.Stream;
 
 @CommandClass(modOnly = true, helpText = {
 	"Component command",
@@ -20,7 +24,8 @@ import java.util.Optional;
 })
 public class ComponentCommand extends ICommand2MC {
 	public ComponentCommand() {
-		getManager().addParamConverter(Plugin.class, arg -> Bukkit.getPluginManager().getPlugin(arg), "Plugin not found!");
+		getManager().addParamConverter(Plugin.class, arg -> Bukkit.getPluginManager().getPlugin(arg), "Plugin not found!",
+			() -> Arrays.stream(Bukkit.getPluginManager().getPlugins()).map(Plugin::getName)::iterator);
 	}
 
 	@Subcommand(helpText = {
@@ -57,6 +62,11 @@ public class ComponentCommand extends ICommand2MC {
 		return true;
 	}
 
+	@CustomTabCompleteMethod(param = "component", subcommand = {"enable", "disable"})
+	public Iterable<String> componentTabcomplete(Plugin plugin) {
+		return getPluginComponents(plugin).map(c -> c.getClass().getSimpleName())::iterator;
+	}
+
 	private boolean enable_disable(CommandSender sender, Plugin plugin, String component, boolean enable, boolean permanent) {
 		try {
 			val oc = getComponentOrError(plugin, component, sender);
@@ -72,10 +82,13 @@ public class ComponentCommand extends ICommand2MC {
 		return true;
 	}
 
+	private Stream<Component<? extends JavaPlugin>> getPluginComponents(Plugin plugin) {
+		return Component.getComponents().values().stream()
+			.filter(c -> plugin.getName().equals(c.getPlugin().getName()));
+	}
+
 	private Optional<Component<?>> getComponentOrError(Plugin plugin, String arg, CommandSender sender) {
-		val oc = Component.getComponents().values().stream()
+		val oc = getPluginComponents(plugin).filter(c -> c.getClass().getSimpleName().equalsIgnoreCase(arg)).findAny();
-			.filter(c -> plugin.getName().equals(c.getPlugin().getName()))
-			.filter(c -> c.getClass().getSimpleName().equalsIgnoreCase(arg)).findAny();
 		if (!oc.isPresent())
 			sender.sendMessage("§cComponent not found!"); //^ Much simpler to solve in the new command system
 		return oc;

Chroma-Core/src/main/java/buttondevteam/core/component/members/MemberCommand.java

@@ -7,6 +7,7 @@ import buttondevteam.lib.chat.ICommand2MC;
 import org.bukkit.Bukkit;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.command.CommandSender;
+import org.bukkit.entity.HumanEntity;
 import org.bukkit.entity.Player;
 
 import java.util.concurrent.TimeUnit;
@@ -19,7 +20,8 @@ public class MemberCommand extends ICommand2MC {
 	private final MemberComponent component;
 
 	public MemberCommand(MemberComponent component) {
-		getManager().addParamConverter(OfflinePlayer.class, Bukkit::getOfflinePlayer, "Player not found!");
+		getManager().addParamConverter(OfflinePlayer.class, Bukkit::getOfflinePlayer, "Player not found!",
+			() -> Bukkit.getOnlinePlayers().stream().map(HumanEntity::getName)::iterator);
 		this.component = component;
 	}
 

Chroma-Core/src/main/java/buttondevteam/core/component/towny/RemoveResidentsCommand.java

@@ -2,6 +2,7 @@ package buttondevteam.core.component.towny;
 
 import buttondevteam.lib.chat.Command2;
 import buttondevteam.lib.chat.CommandClass;
+import buttondevteam.lib.chat.CustomTabComplete;
 import buttondevteam.lib.chat.ICommand2MC;
 import com.palmergames.bukkit.towny.TownySettings;
 import com.palmergames.bukkit.towny.TownyUniverse;
@@ -20,7 +21,7 @@ import java.util.stream.Stream;
 })
 public class RemoveResidentsCommand extends ICommand2MC {
 	@Command2.Subcommand
-	public void def(CommandSender sender, @Command2.OptionalArg String remove) {
+	public void def(CommandSender sender, @Command2.OptionalArg @CustomTabComplete("remove") String remove) {
 		Bukkit.getScheduler().runTaskAsynchronously(getPlugin(), () -> {
 			sender.sendMessage("Starting...");
 			var ds = TownyUniverse.getInstance().getDataSource();

Chroma-Core/src/main/java/buttondevteam/lib/chat/Command2.java

@@ -27,6 +27,7 @@ import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.function.Function;
+import java.util.function.Supplier;
 
 /**
  * The method name is the subcommand, use underlines (_) to add further subcommands.
@@ -110,10 +111,11 @@ public abstract class Command2<TC extends ICommand2<TP>, TP extends Command2Send
 	protected static class ParamConverter<T> {
 		public final Function<String, T> converter;
 		public final String errormsg;
+		public final Supplier<Iterable<String>> allSupplier;
 	}
 
-	protected HashMap<String, SubcommandData<TC>> subcommands = new HashMap<>();
+	protected final HashMap<String, SubcommandData<TC>> subcommands = new HashMap<>();
-	private HashMap<Class<?>, ParamConverter<?>> paramConverters = new HashMap<>();
+	protected final HashMap<Class<?>, ParamConverter<?>> paramConverters = new HashMap<>();
 
 	private ArrayList<String> commandHelp = new ArrayList<>(); //Mainly needed by Discord
 
@@ -123,12 +125,14 @@ public abstract class Command2<TC extends ICommand2<TP>, TP extends Command2Send
 	 * Adds a param converter that obtains a specific object from a string parameter.
 	 * The converter may return null.
 	 *
+	 * @param <T>         The type of the result
 	 * @param cl          The class of the result object
 	 * @param converter   The converter to use
-	 * @param <T>       The type of the result
+	 * @param allSupplier The supplier of all possible values (ideally)
 	 */
-	public <T> void addParamConverter(Class<T> cl, Function<String, T> converter, String errormsg) {
+	public <T> void addParamConverter(Class<T> cl, Function<String, T> converter, String errormsg,
-		paramConverters.put(cl, new ParamConverter<>(converter, errormsg));
+	                                  Supplier<Iterable<String>> allSupplier) {
+		paramConverters.put(cl, new ParamConverter<>(converter, errormsg, allSupplier));
 	}
 
 	public boolean handleCommand(TP sender, String commandline) {

Chroma-Core/src/main/java/buttondevteam/lib/chat/Command2MC.java

@@ -4,11 +4,12 @@ import buttondevteam.core.MainPlugin;
 import buttondevteam.lib.TBMCCoreAPI;
 import buttondevteam.lib.architecture.ButtonPlugin;
 import buttondevteam.lib.architecture.Component;
-import buttondevteam.lib.chat.commandargs.BetterStringArgumentType;
 import com.mojang.brigadier.arguments.*;
 import com.mojang.brigadier.builder.LiteralArgumentBuilder;
 import com.mojang.brigadier.builder.RequiredArgumentBuilder;
+import com.mojang.brigadier.suggestion.SuggestionProvider;
 import com.mojang.brigadier.tree.CommandNode;
+import com.mojang.brigadier.tree.LiteralCommandNode;
 import lombok.val;
 import me.lucko.commodore.Commodore;
 import me.lucko.commodore.CommodoreProvider;
@@ -20,7 +21,9 @@ import org.bukkit.command.CommandSender;
 import org.bukkit.command.ConsoleCommandSender;
 import org.bukkit.command.SimpleCommandMap;
 import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
+import org.bukkit.event.server.TabCompleteEvent;
 import org.bukkit.permissions.Permission;
 import org.bukkit.permissions.PermissionDefault;
 
@@ -31,6 +34,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
 import java.util.function.Function;
+import java.util.function.Supplier;
 
 public class Command2MC extends Command2<ICommand2MC, Command2MCSender> implements Listener {
 	/**
@@ -139,8 +143,8 @@ public class Command2MC extends Command2<ICommand2MC, Command2MCSender> implemen
 	 * {@see super#addParamConverter}
 	 */
 	@Override
-	public <T> void addParamConverter(Class<T> cl, Function<String, T> converter, String errormsg) {
+	public <T> void addParamConverter(Class<T> cl, Function<String, T> converter, String errormsg, Supplier<Iterable<String>> allSupplier) {
-		super.addParamConverter(cl, converter, "§c" + errormsg);
+		super.addParamConverter(cl, converter, "§c" + errormsg, allSupplier);
 	}
 
 	public void unregisterCommands(ButtonPlugin plugin) {
@@ -158,6 +162,13 @@ public class Command2MC extends Command2<ICommand2MC, Command2MCSender> implemen
 			.map(comp -> component.getClass().getSimpleName().equals(comp.getClass().getSimpleName())).orElse(false));
 	}
 
+	@EventHandler
+	public void onTabComplete(TabCompleteEvent event) {
+		//System.out.println("Tabcomplete: " + event.getBuffer());
+		//System.out.println("First completion: " + event.getCompletions().stream().findFirst().orElse("no completions"));
+		event.getCompletions().clear();
+	}
+
 	private boolean shouldRegisterOfficially = true;
 
 	private void registerOfficially(ICommand2MC command, List<SubcommandData<ICommand2MC>> subcmds) {
@@ -202,6 +213,19 @@ public class Command2MC extends Command2<ICommand2MC, Command2MCSender> implemen
 	private static class TabcompleteHelper {
 		private static Commodore commodore;
 
+		private static LiteralCommandNode<Object> appendSubcommand(String path, CommandNode<Object> parent,
+		                                                           SubcommandData<ICommand2MC> subcommand) {
+			var scmdBuilder = LiteralArgumentBuilder.literal(path);
+			if (subcommand != null)
+				scmdBuilder.requires(o -> {
+					var sender = commodore.getBukkitSender(o);
+					return ButtonPlugin.getCommand2MC().hasPermission(sender, subcommand.command, subcommand.method);
+				});
+			var scmd = scmdBuilder.build();
+			parent.addChild(scmd);
+			return scmd;
+		}
+
 		private static void registerTabcomplete(ICommand2MC command2MC, List<SubcommandData<ICommand2MC>> subcmds, Command bukkitCommand) {
 			if (commodore == null)
 				commodore = CommodoreProvider.getCommodore(MainPlugin.Instance); //Register all to the Core, it's easier
@@ -209,18 +233,15 @@ public class Command2MC extends Command2<ICommand2MC, Command2MCSender> implemen
 			var maincmd = LiteralArgumentBuilder.literal(path[0]).build();
 			var cmd = maincmd;
 			for (int i = 1; i < path.length; i++) {
-				var subcmd = LiteralArgumentBuilder.literal(path[i]).build();
+				var scmd = subcmds.stream().filter(sd -> sd.method.getName().equals("def")).findAny().orElse(null);
-				cmd.addChild(subcmd);
+				cmd = appendSubcommand(path[i], cmd, scmd);  //Add each part of the path as a child of the previous one
-				cmd = subcmd; //Add each part of the path as a child of the previous one
 			}
 			for (SubcommandData<ICommand2MC> subcmd : subcmds) {
 				String[] subpath = ButtonPlugin.getCommand2MC().getCommandPath(subcmd.method.getName(), ' ').trim().split(" ");
 				CommandNode<Object> scmd = cmd;
 				if (subpath[0].length() > 0) { //If the method is def, it will contain one empty string
 					for (String s : subpath) {
-						var subsubcmd = LiteralArgumentBuilder.literal(s).build();
+						scmd = appendSubcommand(s, scmd, subcmd); //Add method name part of the path (could_be_multiple())
-						scmd.addChild(subsubcmd);
-						scmd = subsubcmd; //Add method name part of the path (could_be_multiple())
 					}
 				}
 				Parameter[] parameters = subcmd.method.getParameters();
@@ -232,7 +253,7 @@ public class Command2MC extends Command2<ICommand2MC, Command2MCSender> implemen
 						if (parameter.isAnnotationPresent(TextArg.class))
 							type = StringArgumentType.greedyString();
 						else
-							type = BetterStringArgumentType.word();
+							type = StringArgumentType.word();
 					else if (ptype == int.class || ptype == Integer.class
 						|| ptype == byte.class || ptype == Byte.class
 						|| ptype == short.class || ptype == Short.class)
@@ -244,12 +265,18 @@ public class Command2MC extends Command2<ICommand2MC, Command2MCSender> implemen
 					else if (ptype == double.class || ptype == Double.class)
 						type = DoubleArgumentType.doubleArg();
 					else if (ptype == char.class || ptype == Character.class)
-						type = BetterStringArgumentType.word(1);
+						type = StringArgumentType.word();
 					else if (ptype == boolean.class || ptype == Boolean.class)
 						type = BoolArgumentType.bool();
 					else  //TODO: Custom parameter types
-						type = BetterStringArgumentType.word();
+						type = StringArgumentType.word();
-					var arg = RequiredArgumentBuilder.argument(subcmd.parameters[i - 1], type).build();
+					val param = subcmd.parameters[i - 1];
+					var argb = RequiredArgumentBuilder.argument(param, type)
+						.suggests((SuggestionProvider<Object>) (context, builder) -> {
+							//TODO
+							return builder.suggest(param).buildFuture();
+						});
+					var arg = argb.build();
 					scmd.addChild(arg);
 					scmd = arg;
 				}
@@ -263,7 +290,7 @@ public class Command2MC extends Command2<ICommand2MC, Command2MCSender> implemen
 			} catch (Exception e) { - Client log: Could not deserialize chroma:string
 				e.printStackTrace();
 			}*/
-			commodore.register(bukkitCommand, maincmd);
+			commodore.register(maincmd);
 		}
 	}
 }

Chroma-Core/src/main/java/buttondevteam/lib/chat/CustomTabComplete.java

@@ -0,0 +1,15 @@
+package buttondevteam.lib.chat;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Can be used if an argument should be completed with predefined strings.
+ */
+@Target(ElementType.PARAMETER)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface CustomTabComplete {
+	String[] value();
+}

Chroma-Core/src/main/java/buttondevteam/lib/chat/CustomTabCompleteMethod.java

@@ -0,0 +1,23 @@
+package buttondevteam.lib.chat;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * The method must return with {@link String}[] or {@link Iterable}<{@link String}> and may have the sender and preceding arguments as parameters.
+ */
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface CustomTabCompleteMethod {
+	/**
+	 * The parameter's name where we want to give completion
+	 */
+	String param();
+
+	/**
+	 * The subcommand(s) which have the parameter, by default the method's name
+	 */
+	String[] subcommand() default "";
+}

Chroma-Core/src/main/java/buttondevteam/lib/chat/commandargs/BetterStringArgumentType.java

@@ -1,42 +0,0 @@
-package buttondevteam.lib.chat.commandargs;
-
-import com.mojang.brigadier.LiteralMessage;
-import com.mojang.brigadier.StringReader;
-import com.mojang.brigadier.arguments.ArgumentType;
-import com.mojang.brigadier.arguments.StringArgumentType;
-import com.mojang.brigadier.exceptions.CommandSyntaxException;
-import com.mojang.brigadier.exceptions.SimpleCommandExceptionType;
-import lombok.RequiredArgsConstructor;
-
-import java.util.Collection;
-
-@RequiredArgsConstructor
-public class BetterStringArgumentType implements ArgumentType<String> {
-	private final int len;
-
-	public static BetterStringArgumentType word() {
-		return new BetterStringArgumentType(-1);
-	}
-
-	public static BetterStringArgumentType word(int maxlen) {
-		return new BetterStringArgumentType(maxlen);
-	}
-
-	@Override
-	public String parse(StringReader reader) throws CommandSyntaxException {
-		if (len < 1)
-			return reader.readStringUntil(' ');
-
-		final int start = reader.getCursor();
-		if (reader.canRead(len + 1) && reader.peek(len) != ' ')
-			throw new SimpleCommandExceptionType(new LiteralMessage("String too long")).createWithContext(reader);
-		for (int i = 0; i < len; i++)
-			reader.skip();
-		return reader.getString().substring(start, reader.getCursor());
-	}
-
-	@Override
-	public Collection<String> getExamples() {
-		return StringArgumentType.StringType.SINGLE_WORD.getExamples();
-	}
-}