package org.bukkit.command.defaults;

import com.google.common.collect.ImmutableList;
import org.apache.commons.lang.Validate;
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.World;
import org.bukkit.command.BlockCommandSender;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.HumanEntity;
import org.bukkit.util.StringUtil;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class GameRuleCommand extends VanillaCommand
{
	private static final List<String> GAMERULE_STATES = ImmutableList.of("true", "false");

	public GameRuleCommand()
	{
		super("gamerule");
		this.description = "Sets a server's game rules";
		this.usageMessage = "/gamerule <rule name> <value> OR /gamerule <rule name>";
		this.setPermission("bukkit.command.gamerule");
	}

	@Override
	public boolean execute(CommandSender sender, String currentAlias, String[] args)
	{
		if(!testPermission(sender)) return true;

		if(args.length > 0)
		{
			String rule = args[0];
			World world = getGameWorld(sender);

			if(world.isGameRule(rule))
			{
				if(args.length > 1)
				{
					String value = args[1];

					world.setGameRuleValue(rule, value);
					Command.broadcastCommandMessage(sender, "Game rule " + rule + " has been set to: " + value);
				}
				else
				{
					String value = world.getGameRuleValue(rule);
					sender.sendMessage(rule + " = " + value);
				}
			}
			else
			{
				sender.sendMessage(ChatColor.RED + "No game rule called " + rule + " is available");
			}

			return true;
		}
		else
		{
			sender.sendMessage(ChatColor.RED + "Usage: " + usageMessage);
			sender.sendMessage("Rules: " + this.createString(getGameWorld(sender).getGameRules(), 0, ", "));

			return true;
		}
	}

	private World getGameWorld(CommandSender sender)
	{
		if(sender instanceof HumanEntity)
		{
			World world = ((HumanEntity) sender).getWorld();
			if(world != null)
			{
				return world;
			}
		}
		else if(sender instanceof BlockCommandSender)
		{
			return ((BlockCommandSender) sender).getBlock().getWorld();
		}

		return Bukkit.getWorlds().get(0);
	}

	@Override
	public List<String> tabComplete(CommandSender sender, String alias, String[] args) throws IllegalArgumentException
	{
		Validate.notNull(sender, "Sender cannot be null");
		Validate.notNull(args, "Arguments cannot be null");
		Validate.notNull(alias, "Alias cannot be null");

		if(args.length == 1)
		{
			return StringUtil.copyPartialMatches(args[0], Arrays.asList(getGameWorld(sender).getGameRules()), new ArrayList<String>());
		}

		if(args.length == 2)
		{
			return StringUtil.copyPartialMatches(args[1], GAMERULE_STATES, new ArrayList<String>(GAMERULE_STATES.size()));
		}

		return ImmutableList.of();
	}
}