Factions/src/com/massivecraft/factions/engine/EngineExploit.java

package com.massivecraft.factions.engine;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.UUID;

import org.bukkit.block.Block;
import org.bukkit.entity.Player;
import org.bukkit.entity.TNTPrimed;
import org.bukkit.event.block.BlockFromToEvent;
import org.bukkit.event.entity.EntityExplodeEvent;
import org.bukkit.event.player.PlayerMoveEvent;
import org.bukkit.event.player.PlayerTeleportEvent;
import org.bukkit.event.player.PlayerTeleportEvent.TeleportCause;
import org.bukkit.event.EventHandler;
import org.bukkit.event.EventPriority; 
import org.bukkit.Location;
import org.bukkit.Material;

import com.massivecraft.factions.entity.MConf;
import com.massivecraft.massivecore.Engine;
import com.massivecraft.massivecore.ps.PS;
import com.massivecraft.massivecore.util.MUtil;


public class EngineExploit extends Engine
{
	// -------------------------------------------- //
	// INSTANCE & CONSTRUCT
	// -------------------------------------------- //
	
	private static EngineExploit i = new EngineExploit();
	public static EngineExploit get() { return i; }
	
	// -------------------------------------------- //
	// OBSIDIAN GENERATORS
	// -------------------------------------------- //
	
	@SuppressWarnings("deprecation")
	@EventHandler(priority = EventPriority.NORMAL, ignoreCancelled = true)
	public void obsidianGenerators(BlockFromToEvent event)
	{
		if (!MConf.get().handleExploitObsidianGenerators) return;

		// thanks to ObGenBlocker and WorldGuard for this method
		Block block = event.getToBlock();
		int source = event.getBlock().getTypeId();
		int target = block.getTypeId();
		if ((target == 55 || target == 132) && (source == 0 || source == 10 || source == 11))
		{
			block.setType(Material.AIR);
		}
	}

	// -------------------------------------------- //
	// ENDER PEARL CLIPPING
	// -------------------------------------------- //
	
	@EventHandler(priority = EventPriority.NORMAL, ignoreCancelled = true)
	public void enderPearlClipping(PlayerTeleportEvent event)
	{
		if (!MConf.get().handleExploitEnderPearlClipping) return;
		if (event.getCause() != PlayerTeleportEvent.TeleportCause.ENDER_PEARL) return;

		// this exploit works when the target location is within 0.31 blocks or so of a door or glass block or similar...
		Location target = event.getTo();
		Location from = event.getFrom();

		// blocks who occupy less than 1 block width or length wise need to be handled differently
		Material mat = event.getTo().getBlock().getType();
		if (
				((mat == Material.THIN_GLASS || mat == Material.IRON_FENCE) && clippingThrough(target, from, 0.65))
			 || ((mat == Material.FENCE || mat == Material.NETHER_FENCE) && clippingThrough(target, from, 0.45))
			)
		{            
			event.setTo(from);
			return;
		}

		// simple fix otherwise: ender pearl target locations are standardized to be in the center (X/Z) of the target block, not at the edges
		target.setX(target.getBlockX() + 0.5);
		target.setZ(target.getBlockZ() + 0.5);
		event.setTo(target);
		
	}

	public static boolean clippingThrough(Location target, Location from, double thickness)
	{
		return
		(
			(from.getX() > target.getX() && (from.getX() - target.getX() < thickness))
		 || (target.getX() > from.getX() && (target.getX() - from.getX() < thickness))
		 || (from.getZ() > target.getZ() && (from.getZ() - target.getZ() < thickness))
		 || (target.getZ() > from.getZ() && (target.getZ() - from.getZ() < thickness))
		);
	}
	
	// -------------------------------------------- //
	// TNT WATERLOG
	// -------------------------------------------- //
	// TNT in water/lava doesn't normally destroy any surrounding blocks, which is usually desired behavior.
	// But this optional change below provides workaround for waterwalling providing perfect protection,
	// and makes cheap (non-obsidian) TNT cannons require minor maintenance between shots.
	
	@SuppressWarnings("deprecation")
	@EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
	public void tntWaterlog(EntityExplodeEvent event)
	{
		if (!MConf.get().handleExploitTNTWaterlog) return;
		if (!(event.getEntity() instanceof TNTPrimed)) return;
		
		Block center = event.getLocation().getBlock();
		if (!center.isLiquid()) return;
		
		// a single surrounding block in all 6 directions is broken if the material is weak enough
		List<Block> targets = new ArrayList<Block>();
		targets.add(center.getRelative(0, 0, 1));
		targets.add(center.getRelative(0, 0, -1));
		targets.add(center.getRelative(0, 1, 0));
		targets.add(center.getRelative(0, -1, 0));
		targets.add(center.getRelative(1, 0, 0));
		targets.add(center.getRelative(-1, 0, 0));
		for (Block target : targets)
		{
			int id = target.getTypeId();
			// ignore air, bedrock, water, lava, obsidian, enchanting table, etc.... too bad we can't get a blast resistance value through Bukkit yet
			if (id != 0 && (id < 7 || id > 11) && id != 49 && id != 90 && id != 116 && id != 119 && id != 120 && id != 130)
			{
				target.breakNaturally();
			}
		}
	}
	

	// -------------------------------------------- //
	// NETHER PORTAL TRAP 
	// -------------------------------------------- //
	// A nether portal trap can be created by the destination portal being enclosed (trapped) - resulting in the player not being able to run commands.
	// This fix removes the portal blocks (client side) from the destination until they are away from the portal.
	
	private int NETHER_TRAP_RADIUS_CHECK = 5;
	private int NETHER_TRAP_RESET_RADIUS = 3;
	
	private HashMap<UUID, List<Block>> netherTrapBlockSet = new HashMap<UUID, List<Block>>();
	
	// Detect teleport from a nether portal and remove animation if required 
	@EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
	public void netherportalTrapRemoveAnimation(PlayerTeleportEvent event)
	{
		if ( ! MConf.get().handleNetherPortalTrap) return;

		if (event.getCause() != TeleportCause.NETHER_PORTAL) return;

		// If they can build at the target destination then we will not do any further checks 
		if (EngineMain.canPlayerBuildAt(event.getPlayer(), PS.valueOf(event.getTo()), false)) return;
				
		final Player player = event.getPlayer();
		final UUID uuid = player.getUniqueId();
		
		Block from = event.getTo().getBlock();
				
		// If a list exists, then we're dealing with a new portal - so revert the old portal blocks
		this.netherportalReset(player);
		
		// Store some temporary data 
		this.netherTrapBlockSet.put(uuid, this.getPortalBlocks(from));
		
		// Send the air update
		this.netherportalSendAir(player);

	}
	
	// When they leave the portal we will update it, otherwise send the updates again
	@EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
	public void netherportalTrapUpdate(PlayerMoveEvent event)
	{
		if ( ! MConf.get().handleNetherPortalTrap) return;
		
		// Only check if we're changing blocks
		if (MUtil.isSameBlock(event)) return;
		
		Player player = event.getPlayer();
		UUID uuid = player.getUniqueId();
		
		// Check if we're sending updates to this player
		if ( ! this.netherTrapBlockSet.containsKey(uuid)) return;
		
		// If they've changed worlds we don't bother checking this
		if (event.getTo().getWorld() != this.netherTrapBlockSet.get(uuid).get(0).getWorld())
		{
			this.netherportalReset(player);
			return;
		}
			
		// When the player moves away from the portal, we put it back to normal
		if (event.getTo().distance(this.netherTrapBlockSet.get(uuid).get(0).getLocation()) > NETHER_TRAP_RESET_RADIUS)
		{
			this.netherportalReset(player);
		}
		else
		{
			// Send updates as air
			this.netherportalSendAir(player);
		}
	}
	
	// Sends block update to player with original blocks (if required) 
	@SuppressWarnings("deprecation")
	public void netherportalReset(Player player)
	{
		UUID uuid = player.getUniqueId();
		
		if ( ! this.netherTrapBlockSet.containsKey(uuid)) return;
		
		// Only send updates if they're in the same world
		if (this.netherTrapBlockSet.get(uuid).get(0).getWorld() == player.getWorld()) for (Block block : this.netherTrapBlockSet.get(uuid)) player.sendBlockChange(block.getLocation(), block.getType(), block.getData());
		
		// Remove the block set 
		this.netherTrapBlockSet.remove(uuid);
	}
	
	// Send air block updates to player 
	@SuppressWarnings("deprecation")
	public void netherportalSendAir(Player player) 
	{
		for (Block block : this.netherTrapBlockSet.get(player.getUniqueId())) player.sendBlockChange(block.getLocation(), Material.AIR, (byte) 0);
	}
	
	// Get portal blocks near a block 
	public List<Block> getPortalBlocks(Block from) {
		List<Block> blocks = new ArrayList<Block>();
		
		// Check in a radius of the block to find the portal blocks
		for (int x = -(NETHER_TRAP_RADIUS_CHECK); x <= NETHER_TRAP_RADIUS_CHECK; x ++)
		{
			for (int y = -(NETHER_TRAP_RADIUS_CHECK); y <= NETHER_TRAP_RADIUS_CHECK; y ++)
			{
				for (int z = -(NETHER_TRAP_RADIUS_CHECK); z <= NETHER_TRAP_RADIUS_CHECK; z ++)
				{
					if (from.getRelative(x, y, z).getType() == Material.PORTAL)
					{
						// Store block
						blocks.add(from.getRelative(x, y, z));
					}
				}
			}
		}
		
		return blocks;
	}
}