FightSystem/src/me/yaruma/fightsystem/fight/WaterRemover.java

package me.yaruma.fightsystem.fight;

import me.yaruma.fightsystem.FightSystem;
import me.yaruma.fightsystem.winconditions.WinconditionTechKO;
import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.block.Block;
import org.bukkit.block.BlockFace;
import org.bukkit.plugin.Plugin;
import org.bukkit.scheduler.BukkitTask;

import java.util.AbstractMap;
import java.util.ArrayList;
import java.util.List;

public class WaterRemover {

    private List<AbstractMap.SimpleEntry<Location, Integer>> explodedBlocks = new ArrayList<>();
    private List<Block> waterList = new ArrayList<>();
    private BukkitTask task;

    public void start() {
        this.stop();
        this.explodedBlocks = new ArrayList<>();
        this.waterList = new ArrayList<>();
        this.task = Bukkit.getScheduler().runTaskTimerAsynchronously((Plugin)FightSystem.getPlugin(), () -> {
            try {
                WaterRemover.this.wateredCheck();
                WaterRemover.this.removeWater();
            }
            catch (Exception e) {
                e.printStackTrace();
            }
        }, 0L, 20L);
    }

    private void stop() {
        if (this.task != null) {
            this.task.cancel();
        }
    }

    public void add(Location loc) {
        this.explodedBlocks.add(new AbstractMap.SimpleEntry<>(loc, 0));
    }

    private void wateredCheck() {
        for (int i = this.explodedBlocks.size() - 1; i >= 0; i--) {
            if (this.explodedBlocks.get(i).getValue() >= 15) {
                Block b = this.explodedBlocks.get(i).getKey().getBlock();
                if (b.getType() == Material.WATER || b.getType() == Material.STATIONARY_WATER) {
                    this.waterList.add(b);
                }
                this.explodedBlocks.remove(i);
                continue;
            }
            this.explodedBlocks.get(i).setValue(this.explodedBlocks.get(i).getValue() + 1);
        }
    }

    private void removeWater() {
        ArrayList<Block> blocksToRemove = new ArrayList<>();
        for (int i = this.waterList.size() - 1; i > -1; --i) {
            Block current = this.waterList.get(i);
            blocksToRemove.addAll(this.getSourceBlocksOfWater(current));
            if (current.getType() != Material.AIR) continue;
            this.waterList.remove(i);
        }
        Bukkit.getScheduler().runTask((Plugin)FightSystem.getPlugin(), () -> {
            for (Block block : blocksToRemove) {
                block.setType(Material.AIR);
                WinconditionTechKO.removeWater(block.getLocation());
            }
        });
    }

    private List<Block> getSourceBlocksOfWater(Block startBlock) {
        ArrayList<Block> water = new ArrayList<>();
        this.collectBlocks(startBlock, water, new ArrayList<>());
        return water;
    }

    private void collectBlocks(Block anchor, List<Block> collected, List<Block> visitedBlocks) {
        if (anchor.getType() != Material.WATER && anchor.getType() != Material.STATIONARY_WATER) {
            return;
        }
        if (visitedBlocks.contains((Object)anchor)) {
            return;
        }
        visitedBlocks.add(anchor);
        if (anchor.getType() == Material.STATIONARY_WATER) {
            collected.add(anchor);
        }
        this.collectBlocks(anchor.getRelative(BlockFace.UP), collected, visitedBlocks);
        this.collectBlocks(anchor.getRelative(BlockFace.NORTH), collected, visitedBlocks);
        this.collectBlocks(anchor.getRelative(BlockFace.EAST), collected, visitedBlocks);
        this.collectBlocks(anchor.getRelative(BlockFace.SOUTH), collected, visitedBlocks);
        this.collectBlocks(anchor.getRelative(BlockFace.WEST), collected, visitedBlocks);
    }

}