/*
 * This file is part of Limbo.
 *
 * Copyright (C) 2022. LoohpJames <jamesloohp@gmail.com>
 * Copyright (C) 2022. Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.loohp.limbo.scheduler;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;

import com.loohp.limbo.Limbo;
import com.loohp.limbo.scheduler.LimboScheduler.CurrentSchedulerTask;
import com.loohp.limbo.scheduler.LimboScheduler.LimboSchedulerTask;

public class Tick {
	
	private int tickingInterval;
	private AtomicLong tick = new AtomicLong(0);
	
	private List<Thread> threads = new ArrayList<>();
	private Queue<LimboSchedulerTask> asyncTasksQueue = new ConcurrentLinkedQueue<>();
	
	public Tick(Limbo instance) {
		new Thread(() -> {
			tickingInterval = (int) Math.round(1000.0 / Limbo.getInstance().getServerProperties().getDefinedTicksPerSecond());

			for (int i = 0; i < 4; i++) {
				Thread thread = new Thread(() -> {
					while (instance.isRunning()) {
						LimboSchedulerTask task = asyncTasksQueue.poll();
						if (task == null) {
							try {
								TimeUnit.NANOSECONDS.sleep(10000);
							} catch (InterruptedException e) {
								e.printStackTrace();
							}
						} else {
							LimboTask limboTask = task.getTask();
							try {
								limboTask.run();
							} catch (Throwable e) {
								System.err.println("Task " + task.getTaskId() + " threw an exception: " + e.getLocalizedMessage());
								e.printStackTrace();
							}
						}
					}
				});
				thread.start();
				threads.add(thread);
			}

			while (instance.isRunning()) {
				long start = System.currentTimeMillis();
				tick.incrementAndGet();
				instance.getPlayers().forEach(each -> {
					if (each.clientConnection.isReady()) {
						try {
							each.playerInteractManager.update();
						} catch (IOException e) {
							e.printStackTrace();
						}
						/*
						try {
							each.getDataWatcher().update();
						} catch (IllegalArgumentException | IllegalAccessException e) {
							e.printStackTrace();
						}
						*/
					}
				});
				instance.getWorlds().forEach(each -> {
					try {
						each.update();
					} catch (IllegalArgumentException | IllegalAccessException e) {
						e.printStackTrace();
					}
				});

				CurrentSchedulerTask tasks = instance.getScheduler().collectTasks(getCurrentTick());
				if (tasks != null) {
					asyncTasksQueue.addAll(tasks.getAsyncTasks());

					tasks.getSyncedTasks().forEach(task -> {
						LimboTask limboTask = task.getTask();
						try {
							limboTask.run();
						} catch (Throwable e) {
							System.err.println("Task " + task.getTaskId() + " threw an exception: " + e.getLocalizedMessage());
							e.printStackTrace();
						}
					});
				}

				long end = System.currentTimeMillis();
				try {
					TimeUnit.MILLISECONDS.sleep(tickingInterval - (end - start));
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
		}).start();
	}
	
	public long getCurrentTick() {
		return tick.get();
	}
	
	@SuppressWarnings("deprecation")
	public void waitAndKillThreads(long waitTime) {
		long end = System.currentTimeMillis() + waitTime;
		for (Thread thread : threads) {
			try {
				thread.join(Math.max(end - System.currentTimeMillis(), 1));
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			if (thread.isAlive()) {
				thread.stop();
			}
		}
	}
	
}