BlockEventHandler.java

/*
    PopulationDensity Server Plugin for Minecraft
    Copyright (C) 2011 Ryan Hamshire

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package me.ryanhamshire.PopulationDensity;

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

import org.bukkit.ChatColor;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.block.Block;
import org.bukkit.block.BlockFace;
import org.bukkit.block.BlockState;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.EventPriority;
import org.bukkit.event.Listener;
import org.bukkit.event.block.BlockBreakEvent;
import org.bukkit.event.block.BlockDamageEvent;
import org.bukkit.event.block.BlockFromToEvent;
import org.bukkit.event.block.BlockPistonExtendEvent;
import org.bukkit.event.block.BlockPistonRetractEvent;
import org.bukkit.event.block.BlockPlaceEvent;

public class BlockEventHandler implements Listener 
{
    private static List<Material> alwaysBreakableMaterials = Arrays.asList(
        Material.LONG_GRASS,
        Material.DOUBLE_PLANT,
        Material.LOG,
        Material.LOG_2,
        Material.LEAVES,
        Material.LEAVES_2,
        Material.RED_ROSE,
        Material.YELLOW_FLOWER,
        Material.SNOW_BLOCK
    );
    
	//when a player breaks a block...
	@EventHandler(ignoreCancelled = true)
	public void onBlockBreak(BlockBreakEvent breakEvent)
	{
		Player player = breakEvent.getPlayer();
		
		PopulationDensity.instance.resetIdleTimer(player);
		
		Block block = breakEvent.getBlock();
		
		//if the player is not in managed world, do nothing (let vanilla code and other plugins do whatever)
		if(!player.getWorld().equals(PopulationDensity.ManagedWorld)) return;
		
		//otherwise figure out which region that block is in
		Location blockLocation = block.getLocation();
		
		//region posts are at sea level at the lowest, so no need to check build permissions under that
		if(blockLocation.getBlockY() < PopulationDensity.instance.minimumRegionPostY) return;
		
		//whitelist for blocks which can always be broken (grass cutting, tree chopping)
		if(BlockEventHandler.alwaysBreakableMaterials.contains(block.getType())) return;
		
		RegionCoordinates blockRegion = RegionCoordinates.fromLocation(blockLocation); 
		
		//if too close to (or above) region post, send an error message
		//note the ONLY way to edit around a region post is to have special permission
		if(!player.hasPermission("populationdensity.buildbreakanywhere") && this.nearRegionPost(blockLocation, blockRegion, PopulationDensity.instance.postProtectionRadius))
		{
			if(PopulationDensity.instance.buildRegionPosts)
			    PopulationDensity.sendMessage(player, TextMode.Err, Messages.NoBreakPost);
			else
			    PopulationDensity.sendMessage(player, TextMode.Err, Messages.NoBreakSpawn);
			breakEvent.setCancelled(true);
			return;
		}
	}
	
	private Location lastLocation = null;
	private Boolean lastResult = null;
	@EventHandler(ignoreCancelled = true, priority = EventPriority.HIGHEST)
	public void onBlockFromTo(BlockFromToEvent event)
	{
	    if(event.getFace() == BlockFace.DOWN) return;
	    
	    Location from = event.getBlock().getLocation();
	    if(lastLocation != null && from.equals(lastLocation))
	    {
	        event.setCancelled(lastResult);
	        return;
	    }
	    
	    //if not in managed world, do nothing
        if(!from.getWorld().equals(PopulationDensity.ManagedWorld)) return;
        
        //region posts are at sea level at the lowest, so no need to check build permissions under that
        if(from.getY() < PopulationDensity.instance.minimumRegionPostY) return;
        
        RegionCoordinates blockRegion = RegionCoordinates.fromLocation(from);
        if(this.nearRegionPost(from, blockRegion, PopulationDensity.instance.postProtectionRadius + 1))
        {
            event.setCancelled(true);
            lastResult = true;
        }
        else
        {
            lastResult = false;
        }
        
        lastLocation = from;
	}
	
	//when a player places a block
	@EventHandler(ignoreCancelled = true)
	public void onBlockPlace(BlockPlaceEvent placeEvent)
	{
		Player player = placeEvent.getPlayer();
		
		PopulationDensity.instance.resetIdleTimer(player);
		
		Block block = placeEvent.getBlock();
		
		//if not in managed world, do nothing
		if(!player.getWorld().equals(PopulationDensity.ManagedWorld)) return;
		
		Location blockLocation = block.getLocation();
		
		//region posts are at sea level at the lowest, so no need to check build permissions under that
		if(blockLocation.getBlockY() < PopulationDensity.instance.minimumRegionPostY) return;
		
		RegionCoordinates blockRegion = RegionCoordinates.fromLocation(blockLocation); 
		
		//if too close to (or above) region post, send an error message
		if(!player.hasPermission("populationdensity.buildbreakanywhere") && this.nearRegionPost(blockLocation, blockRegion, PopulationDensity.instance.postProtectionRadius))
		{
			if(PopulationDensity.instance.buildRegionPosts)
				PopulationDensity.sendMessage(player, TextMode.Err, Messages.NoBuildPost);
			else
			    PopulationDensity.sendMessage(player, TextMode.Err, Messages.NoBuildSpawn);
			placeEvent.setCancelled(true);
			return;
		}
		
		//if over hopper limit for chunk, send error message
		Material type = null;
		if(!player.hasPermission("populationdensity.unlimitedhoppers"))
		{
		    type = block.getType();
		    if(type == Material.HOPPER)
		    {
		        int hopperCount = 0;
		        BlockState [] tiles = block.getChunk().getTileEntities();
		        for(BlockState tile : tiles)
		        {
		            if(tile.getType() == Material.HOPPER && ++hopperCount >= PopulationDensity.instance.config_maximumHoppersPerChunk)
		            {
		                placeEvent.setCancelled(true);
		                PopulationDensity.sendMessage(player, TextMode.Err, Messages.HopperLimitReached, String.valueOf(PopulationDensity.instance.config_maximumHoppersPerChunk));
		                return;
		            }
		        }
		    }
		}
		
		//if bed or chest and player has not been reminded about /movein this play session
		if(type == null) type = block.getType();
		if(type == Material.BED || type == Material.CHEST)
		{
			PlayerData playerData = PopulationDensity.instance.dataStore.getPlayerData(player);
			if(playerData.advertisedMoveInThisSession) return;
			
			if(!playerData.homeRegion.equals(blockRegion))
			{
				PopulationDensity.sendMessage(player, TextMode.Warn, Messages.BuildingAwayFromHome);
				playerData.advertisedMoveInThisSession = true;
			}
		}
	}
	
	//when a player damages a block...
    @EventHandler(ignoreCancelled = true)
    public void onBlockDamage(BlockDamageEvent damageEvent)
    {
        Player player = damageEvent.getPlayer();
        
        Block block = damageEvent.getBlock();
        if(player == null || (block.getType() != Material.WALL_SIGN && block.getType() != Material.SIGN_POST)) return;
        
        //if the player is not in managed world, do nothing
        if(!player.getWorld().equals(PopulationDensity.ManagedWorld)) return;
        
        if(!this.nearRegionPost(block.getLocation(), RegionCoordinates.fromLocation(block.getLocation()), 1)) return;
        
        PopulationDensity.sendMessage(player, TextMode.Instr, Messages.HelpMessage1, ChatColor.UNDERLINE + "" + ChatColor.AQUA + "http://bit.ly/mcregions");
    }
    
    @EventHandler(ignoreCancelled = true, priority = EventPriority.LOWEST)
    public void onBlockPistonExtend (BlockPistonExtendEvent event)
    {       
        Block pistonBlock = event.getBlock();
        
        if(!pistonBlock.getWorld().equals(PopulationDensity.ManagedWorld)) return;
        
        RegionCoordinates pistonRegion = RegionCoordinates.fromLocation(pistonBlock.getLocation());
        if(this.nearRegionPost(pistonBlock.getLocation(), pistonRegion, PopulationDensity.instance.postProtectionRadius + 6))
        {
            List<Block> blocks = event.getBlocks();
            for(Block block : blocks)
            {
                if(this.nearRegionPost(block.getLocation(), pistonRegion, PopulationDensity.instance.postProtectionRadius + 1))
                {
                    event.setCancelled(true);
                    return;
                }
            }
        }
    }
    
    @EventHandler(ignoreCancelled = true, priority = EventPriority.LOWEST)
    public void onBlockPistonRetract (BlockPistonRetractEvent event)
    {
        Block pistonBlock = event.getBlock();
        
        if(!pistonBlock.getWorld().equals(PopulationDensity.ManagedWorld)) return;
        
        RegionCoordinates pistonRegion = RegionCoordinates.fromLocation(pistonBlock.getLocation());
        if(this.nearRegionPost(pistonBlock.getLocation(), pistonRegion, PopulationDensity.instance.postProtectionRadius + 2))
        {
            List<Block> blocks = event.getBlocks();
            for(Block block : blocks)
            {
                if(this.nearRegionPost(block.getLocation(), pistonRegion, PopulationDensity.instance.postProtectionRadius))
                {
                    event.setCancelled(true);
                    return;
                }
            }
        }
    }
	
	//determines whether or not you're "near" a region post
	private boolean nearRegionPost(Location location, RegionCoordinates region, int howClose)
	{
		Location postLocation = PopulationDensity.getRegionCenter(region, false);
		
		//NOTE!  Why not use distance?  Because I want a box to the sky, not a sphere.
		//Why not round?  Below calculation is cheaper than distance (needed for a cylinder or sphere).
		//Why to the sky?  Because if somebody builds a platform above the post, folks will teleport onto that platform by mistake.
		//Also...  lava from above would be bad.
		//Why not below?  Because I can't imagine mining beneath a post as an avenue for griefing. 
		
		return (	location.getBlockX() >= postLocation.getBlockX() - howClose &&
					location.getBlockX() <= postLocation.getBlockX() + howClose &&
					location.getBlockZ() >= postLocation.getBlockZ() - howClose &&
					location.getBlockZ() <= postLocation.getBlockZ() + howClose &&
					location.getBlockY() >= PopulationDensity.ManagedWorld.getHighestBlockYAt(postLocation) - 4
				);
	}
}