Command.java

/**
 *   Copyright 2015 Alexander Sagen <alexmsagen@gmail.com> and Thomas Strømmen <thomasstrommen@hotmail.com>
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
package org.pzyko.sh.command;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;

import org.bukkit.Bukkit;
import org.bukkit.command.CommandMap;
import org.bukkit.command.CommandSender;
import org.bukkit.command.TabExecutor;
import org.bukkit.entity.Player;
import org.bukkit.permissions.Permission;

public abstract class Command implements TabExecutor {

    private class ReflectCommand extends org.bukkit.command.Command {

        private TabExecutor exe = null;

        protected ReflectCommand(String command) {
            super(command);
        }

        @Override
        public boolean execute(CommandSender sender, String commandLabel, String[] args) {
            if (exe != null) {
                exe.onCommand(sender, this, commandLabel, args);
            }
            return false;
        }

        public void setExecutor(TabExecutor exe) {
            this.exe = exe;
        }

        @Override
        public List<String> tabComplete(CommandSender sender, String alias, String[] args) {
            if (exe != null)
                return exe.onTabComplete(sender, this, alias, args);
            return null;
        }
    }

    protected String command;
    protected String description;
    protected List<String> alias;
    protected String usage;
    protected String permMessage;

    protected static CommandMap cmap;

    public Command(String command) {
        this(command, null, null, null, null);
    }

    public Command(String command, String usage) {
        this(command, usage, null, null, null);
    }

    public Command(String command, String usage, String description) {
        this(command, usage, description, null, null);
    }

    public Command(String command, String usage, String description, List<String> aliases) {
        this(command, usage, description, null, aliases);
    }

    public Command(String command, String usage, String description, String permissionMessage) {
        this(command, usage, description, permissionMessage, null);
    }

    public Command(String command, String usage, String description, String permissionMessage, List<String> aliases) {
        this.command = command.toLowerCase();
        this.usage = usage;
        this.description = description;
        this.permMessage = permissionMessage;
        this.alias = aliases;
        register();
    }

    CommandMap getCommandMap() {
        if (cmap == null) {
            try {
                Field f = Bukkit.getServer().getClass().getDeclaredField("commandMap");
                f.setAccessible(true);
                cmap = (CommandMap) f.get(Bukkit.getServer());
                return getCommandMap();
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else if (cmap != null) {
            return cmap;
        }
        return getCommandMap();
    }

    public boolean isAuthorized(CommandSender sender,
            Permission perm) {
        return sender.hasPermission(perm);
    }

    public boolean isAuthorized(CommandSender sender,
            String permission) {
        return sender.hasPermission(permission);
    }

    public boolean isAuthorized(Player player, Permission perm) {
        return player.hasPermission(perm);
    }

    public boolean isAuthorized(Player player, String permission) {
        return player.hasPermission(permission);
    }

    public boolean isPlayer(CommandSender sender) {
        return (sender instanceof Player);
    }

    @Override
    public abstract boolean onCommand(CommandSender sender, org.bukkit.command.Command command, String label, String[] args);

    @Override
    public List<String> onTabComplete(CommandSender sender, org.bukkit.command.Command command, String label, String[] args) {
     ArrayList<String> players = new ArrayList<String>();
        for (Player o : Bukkit.getOnlinePlayers()) {
            if (o.getName().toUpperCase().startsWith(args[args.length - 1].toUpperCase())) {
                players.add(o.getName());
            }
        }
        return players;
    }

    public void register() {
        ReflectCommand cmd = new ReflectCommand(this.command);
        if (this.alias != null) {
            cmd.setAliases(this.alias);
        }
        if (this.description != null) {
            cmd.setDescription(this.description);
        }
        if (this.usage != null) {
            cmd.setUsage(this.usage);
        }
        if (this.permMessage != null) {
            cmd.setPermissionMessage(this.permMessage);
        }
        String fallback = "";
        if(alias != null && !alias.isEmpty()) fallback = alias.get(0);
        getCommandMap().register(fallback, cmd);
        cmd.setExecutor(this);
    };

}