Add tab completion

bukkit/src/main/java/me/lucko/luckperms/CommandManagerBukkit.java

@@ -5,19 +5,32 @@ import me.lucko.luckperms.commands.Sender;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
+import org.bukkit.command.TabExecutor;
 
 import java.lang.ref.WeakReference;
 import java.util.Arrays;
+import java.util.List;
 
-class CommandManagerBukkit extends CommandManager implements CommandExecutor {
+class CommandManagerBukkit extends CommandManager implements CommandExecutor, TabExecutor {
     CommandManagerBukkit(LuckPermsPlugin plugin) {
         super(plugin);
     }
 
     @Override
     public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
-        final WeakReference<CommandSender> cs = new WeakReference<>(sender);
-        return onCommand(new Sender() {
+        return onCommand(makeSender(sender), Arrays.asList(args));
+    }
+
+
+    @Override
+    public List<String> onTabComplete(CommandSender sender, Command command, String label, String[] args) {
+        return onTabComplete(makeSender(sender), Arrays.asList(args));
+    }
+
+    private static Sender makeSender(CommandSender sender) {
+        return new Sender() {
+            final WeakReference<CommandSender> cs = new WeakReference<>(sender);
+
             @Override
             public void sendMessage(String s) {
                 final CommandSender c = cs.get();
@@ -31,6 +44,6 @@ class CommandManagerBukkit extends CommandManager implements CommandExecutor {
                 final CommandSender c = cs.get();
                 return c != null && c.hasPermission(node);
             }
-        }, Arrays.asList(args));
+        };
     }
 }

bukkit/src/main/java/me/lucko/luckperms/LPBukkitPlugin.java

@@ -16,12 +16,15 @@ import me.lucko.luckperms.utils.LPConfiguration;
 import me.lucko.luckperms.vaulthooks.VaultHook;
 import org.bukkit.Bukkit;
 import org.bukkit.command.PluginCommand;
+import org.bukkit.entity.Player;
 import org.bukkit.plugin.PluginManager;
 import org.bukkit.plugin.java.JavaPlugin;
 
 import java.io.File;
 import java.util.Arrays;
+import java.util.List;
 import java.util.UUID;
+import java.util.stream.Collectors;
 
 @Getter
 public class LPBukkitPlugin extends JavaPlugin implements LuckPermsPlugin {
@@ -45,6 +48,7 @@ public class LPBukkitPlugin extends JavaPlugin implements LuckPermsPlugin {
         CommandManagerBukkit commandManager = new CommandManagerBukkit(this);
         PluginCommand main = getServer().getPluginCommand("luckperms");
         main.setExecutor(commandManager);
+        main.setTabCompleter(commandManager);
         main.setAliases(Arrays.asList("perms", "lp", "permissions", "p", "perm"));
 
         final String storageMethod = configuration.getStorageMethod();
@@ -123,6 +127,11 @@ public class LPBukkitPlugin extends JavaPlugin implements LuckPermsPlugin {
         return getServer().getOnlinePlayers().size();
     }
 
+    @Override
+    public List<String> getPlayerList() {
+        return getServer().getOnlinePlayers().stream().map(Player::getName).collect(Collectors.toList());
+    }
+
     @Override
     public void runUpdateTask() {
         getServer().getScheduler().runTaskAsynchronously(this, new UpdateTask(this));