BauSystem/src/de/warking/bausystem/world/TNTTracer.java

package de.warking.bausystem.world;

import de.warking.bausystem.BauSystem;
import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.World;
import org.bukkit.block.Block;
import org.bukkit.entity.Entity;
import org.bukkit.entity.Player;
import org.bukkit.entity.TNTPrimed;
import org.bukkit.event.EventHandler;
import org.bukkit.event.HandlerList;
import org.bukkit.event.Listener;
import org.bukkit.event.world.WorldUnloadEvent;
import org.bukkit.scheduler.BukkitTask;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

public class TNTTracer implements Listener, Runnable {

    private static final Map<World, TNTTracer> allTracer = new HashMap<>();

    private final World world;
    private final BukkitTask task;
    private final Set<Location> locations;
    private boolean printed;

    private TNTTracer(World world){
        this.world = world;
        this.locations = new HashSet<>();
        this.printed = false;
        this.task = Bukkit.getScheduler().runTaskTimer(BauSystem.getInstance(), this, 1, 1);
        Bukkit.getPluginManager().registerEvents(this, BauSystem.getInstance());
        allTracer.put(world, this);
    }

    private void stop(){
        task.cancel();
        HandlerList.unregisterAll(this);
    }

    public void end(){
        stop();
        locations.clear();
        allTracer.remove(world);
    }

    public void show(){
        stop();
        printed = true;
        Set<Location> unsetLoc = new HashSet<>();
        for(Location l : locations){
            Block b = world.getBlockAt(l);
            if(b.getType() != Material.AIR){
                unsetLoc.add(l);
                continue;
            }
            b.setType(Material.STAINED_GLASS);
            b.setData((byte) 1);
        }
        locations.removeAll(unsetLoc);
    }

    public void hide(){
        if(!printed)
            return;
        for(Location l : locations){
            Block b = world.getBlockAt(l);
            if(b.getType() != Material.STAINED_GLASS || b.getData() != 1)
                continue;
            b.setType(Material.AIR);
        }
        end();
    }

    @EventHandler
    public void onUnloadWorld(WorldUnloadEvent e){
        if(e.getWorld().equals(world)){
            end();
        }
    }

    @Override
    public void run() {
        if(locations.size() < 20000){
            for(Entity e : world.getEntitiesByClass(TNTPrimed.class)){
                locations.add(e.getLocation());
            }
            if(locations.size() >= 20000){
                for(Player p : world.getPlayers()){
                    p.sendMessage(BauSystem.PREFIX + "§cEs werden keine weiteren Positionen mehr erfasst (20.000 Block Limit)");
                }
            }
        }
    }

    public static void newTracer(World w){
        if(allTracer.containsKey(w)){
            TNTTracer existing = allTracer.get(w);
            existing.end();
        }
        new TNTTracer(w);
    }

    public static TNTTracer get(World w){
        return allTracer.get(w);
    }
}