Factions3/src/main/java/net/knarcraft/factions/engine/EngineExploit.java

package net.knarcraft.factions.engine;

import com.massivecraft.massivecore.Engine;
import com.massivecraft.massivecore.collections.MassiveList;
import com.massivecraft.massivecore.ps.PS;
import com.massivecraft.massivecore.util.MUtil;
import net.knarcraft.factions.entity.MConf;
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.event.EventHandler;
import org.bukkit.event.EventPriority;
import org.bukkit.event.block.BlockFromToEvent;
import org.bukkit.event.player.PlayerMoveEvent;
import org.bukkit.event.player.PlayerTeleportEvent;
import org.bukkit.event.player.PlayerTeleportEvent.TeleportCause;

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

public class EngineExploit extends Engine {
    // -------------------------------------------- //
    // INSTANCE & CONSTRUCT
    // -------------------------------------------- //

    private static final EngineExploit i = new EngineExploit();

    public static EngineExploit get() {
        return i;
    }

    // -------------------------------------------- //
    // OBSIDIAN GENERATORS
    // -------------------------------------------- //

    @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();
        Material source = event.getBlock().getType();
        Material target = block.getType();
        if ((target == Material.REDSTONE_WIRE || target == Material.TRIPWIRE) && (source == Material.AIR || source == Material.LAVA)) {
            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.GLASS_PANE || mat == Material.IRON_BARS) && clippingThrough(target, from, 0.65))
                        || ((MUtil.list(Material.ACACIA_FENCE, Material.BIRCH_FENCE, Material.DARK_OAK_FENCE, Material.JUNGLE_FENCE, Material.NETHER_BRICK_FENCE, Material.OAK_FENCE, Material.SPRUCE_FENCE).contains(mat)) && 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))
                );
    }

    // -------------------------------------------- //
    // 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 final HashMap<UUID, List<Block>> portalTraps = new HashMap<>();

    @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.NETHER_PORTAL) {
                        ret.add(from.getRelative(x, y, z));
                    }
                }
            }
        }

        // Return
        return ret;
    }

}