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

package com.massivecraft.factions.engine;

import com.massivecraft.factions.entity.MConf;
import com.massivecraft.massivecore.Engine;
import com.massivecraft.massivecore.collections.MassiveList;
import com.massivecraft.massivecore.ps.PS;
import com.massivecraft.massivecore.util.MUtil;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.World;
import org.bukkit.block.Block;
import org.bukkit.entity.Player;
import org.bukkit.entity.TNTPrimed;
import org.bukkit.event.EventHandler;
import org.bukkit.event.EventPriority;
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 java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.UUID;

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 static final int NETHER_TRAP_RADIUS_CHECK = 5;
	private static final int NETHER_TRAP_RESET_RADIUS_SQUARED = 9;
	
	private HashMap<UUID, List<Block>> portalTraps = new HashMap<UUID, List<Block>>();
	
	@EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
	public void portalTrapRemoveAnimation(PlayerTeleportEvent event)
	{
		// If there is a teleport caused by a nether portal ...
		if ( ! MConf.get().handleNetherPortalTrap || event.getCause() != TeleportCause.NETHER_PORTAL) return;

		Player player = event.getPlayer();
		Block from = event.getTo().getBlock();

		// ... and the player can't build at the destination ...
		if (EnginePermBuild.canPlayerBuildAt(player, PS.valueOf(from), false)) return;
				
		// ... reset the old portal blocks stored ...
		this.portalReset(player);
		
		// ... get all the portal blocks belonging to the new portal at the destination ...
		List<Block> portalTrap = getPortal(from);
		if (portalTrap.isEmpty()) return;

		// ... and then store those blocks and send an update as if they were air.
		this.portalTraps.put(player.getUniqueId(), portalTrap);
		portalUpdateAir(player, portalTrap);
	}
	
	@EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
	public void portalUpdate(PlayerMoveEvent event)
	{
		// If a player moves ...
		if ( ! MConf.get().handleNetherPortalTrap || MUtil.isSameBlock(event)) return;
		
		Player player = event.getPlayer();
		UUID uuid = player.getUniqueId();
		
		// ... and he recently used a portal ...
		List<Block> portalTrap = this.portalTraps.get(uuid);
		if (portalTrap == null) return;

		Location locationTo = event.getTo();
		Location locationFrom = portalTrap.get(0).getLocation();

		World worldTo = locationTo.getWorld();
		World worldFrom = locationFrom.getWorld();

		// ... update reset the portal near them, if they have moved away too far ...
		if ( ! worldTo.equals(worldFrom) || locationTo.distanceSquared(locationFrom) > NETHER_TRAP_RESET_RADIUS_SQUARED)
		{
			portalUpdateReset(player, portalTrap);
			return;
		}

		// ... or send an update as if the portal blocks were air.
		portalUpdateAir(player, portalTrap);
	}
	
	public void portalReset(Player player)
	{
		UUID uuid = player.getUniqueId();

		// If a player has already a portal registered to him ...
		List<Block> portalTrap = this.portalTraps.get(uuid);
		if (portalTrap == null) return;

		// ... remove them from the registry ...
		this.portalTraps.remove(uuid);
		
		// ... and send updates if the player and portal are in the same world.
		if ( ! player.getWorld().equals(portalTrap.get(0).getWorld())) return;
		portalUpdateReset(player, portalTrap);
	}

	public static void portalUpdateReset(Player player, List<Block> portal) { portalUpdate(player, portal, null, null); }
	public static void portalUpdateAir(Player player, List<Block> portal) { portalUpdate(player, portal, Material.AIR, (byte) 0); }

	@SuppressWarnings("deprecation")
	private static void portalUpdate(Player player, List<Block> portal, Material material, Byte data)
	{
		boolean usingDefault = material == null && data == null;
		for (Block block : portal)
		{
			Material updateMaterial = usingDefault ? block.getType() : material;
			byte updateData = usingDefault ? block.getData() : data;
			player.sendBlockChange(block.getLocation(), updateMaterial, updateData);
		}
	}

	public static List<Block> getPortal(Block from)
	{
		// Create
		List<Block> ret = new MassiveList<>();
		
		// Fill - 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) ret.add(from.getRelative(x, y, z));
				}
			}
		}

		// Return
		return ret;
	}

}