/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * http://www.gnu.org/copyleft/gpl.html
 */
package net.sf.l2j.gameserver;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.ScheduledFuture;
import java.util.logging.Logger;

import javolution.util.FastList;
import net.sf.l2j.gameserver.ai.CtrlEvent;
import net.sf.l2j.gameserver.instancemanager.DayNightSpawnManager;
import net.sf.l2j.gameserver.model.L2Character;
import java.util.concurrent.locks.*;

/**
 * This class ...
 * 
 * @version $Revision: 1.1.4.8 $ $Date: 2005/04/06 16:13:24 $
 */
public class GameTimeController
{
	static final Logger _log = Logger.getLogger(GameTimeController.class.getName());

	public static final int TICKS_PER_SECOND = 10;
	public static final int MILLIS_IN_TICK = 1000 / TICKS_PER_SECOND;

	private static GameTimeController _instance = new GameTimeController();

	protected static int _gameTicks;
	protected static long _gameStartTime;
	protected static boolean _isNight = false;

	private static FastList<L2Character> _movingObjects = new FastList<L2Character>();

	protected static TimerThread _timer;
	protected static MoveObjectsThread _mover;
	private ScheduledFuture _timerWatcher;

	public final Lock lock = new ReentrantLock();
	public final Condition tickCondition  = lock.newCondition(); 

	/**
	 * one ingame day is 240 real minutes
	 */
	public static GameTimeController getInstance()
	{
		return _instance;
	}

	private GameTimeController()
	{
		_gameStartTime = System.currentTimeMillis() - 3600000; // offset so that the server starts a day begin
		_gameTicks = 3600000 / MILLIS_IN_TICK; // offset so that the server starts a day begin

		_timer = new TimerThread();
		_timer.start();

		_mover = new MoveObjectsThread(_movingObjects);
		_mover.start();
		
		_timerWatcher = ThreadPoolManager.getInstance().scheduleGeneralAtFixedRate(new TimerWatcher(), 0, 1000);
        ThreadPoolManager.getInstance().scheduleGeneralAtFixedRate(new BroadcastSunState(), 0, 600000);

	}

	public boolean isNowNight()
	{
		return _isNight;
	}

	public int getGameTime()
	{
		return (_gameTicks / (TICKS_PER_SECOND * 10));
	}

	public static int getGameTicks()
	{
		return _gameTicks;
	}

	/**
	 * Add a L2Character to movingObjects of GameTimeController.<BR><BR>
	 * 
	 * <B><U> Concept</U> :</B><BR><BR>
	 * All L2Character in movement are identified in <B>movingObjects</B> of GameTimeController.<BR><BR>
	 * 
	 * @param cha The L2Character to add to movingObjects of GameTimeController
	 * 
	 */
	public void registerMovingObject(L2Character cha)
	{
		if(cha == null) return;
		synchronized(_movingObjects) {
			if (!_movingObjects.contains(cha)) _movingObjects.add(cha);
		}
	}

	/**
	 * Move all L2Characters contained in movingObjects of GameTimeController.<BR><BR>
	 * 
	 * <B><U> Concept</U> :</B><BR><BR>
	 * All L2Character in movement are identified in <B>movingObjects</B> of GameTimeController.<BR><BR>
	 * 
	 * <B><U> Actions</U> :</B><BR><BR>
	 * <li>Update the position of each L2Character </li>
	 * <li>If movement is finished, the L2Character is removed from movingObjects </li>
	 * <li>Create a task to update the _knownObject and _knowPlayers of each L2Character that finished its movement and of their already known L2Object then notify AI with EVT_ARRIVED </li><BR><BR>
	 * 
	 */
	   
	class MoveObjectsThread extends Thread {
		private final FastList<L2Character> chars;
		private int oldticks;
		public MoveObjectsThread(FastList<L2Character> _chars)
		{
			chars = _chars;
		}
		public void run()
		{
			L2Character cha;
			for (;;) {
				
				lock.lock();
				try
				{
					while (oldticks == _gameTicks || chars.isEmpty()) 
					{
						if (oldticks != _gameTicks) oldticks = _gameTicks;
						tickCondition.await();
					}
				} catch (InterruptedException e) { return; }
				finally {lock.unlock();}
					
				for (FastList.Node<L2Character> e = chars.head(), end = chars.tail(); e!=end; e = e.getNext())
				{
					cha = e.getValue();
					if (cha.updatePosition(_gameTicks))
					{
						synchronized (chars) { chars.remove(cha); }
						ThreadPoolManager.getInstance().executeTask(new MovingObjectArrived(cha));
					}
				}
				oldticks = _gameTicks;
			}
		}
	}
	
	public void stopTimer()
	{
		_timerWatcher.cancel(true);
		_timer.interrupt();
		_mover.interrupt();
	}

	class TimerThread extends Thread
	{
		protected Exception _error;

		public TimerThread()
		{
			super("GameTimeController");
			setDaemon(true);
			setPriority(MAX_PRIORITY);
			_error = null;
		}

		@Override
		public void run()
		{
			try
			{				
				for (;;)
				{
					lock.lock();
					int _oldTicks=_gameTicks; // save old ticks value to avoid moving objects 2x in same tick	
					long runtime = System.currentTimeMillis() - _gameStartTime; // from server boot to now

					_gameTicks = (int) (runtime / MILLIS_IN_TICK); // new ticks value (ticks now) 

					if (_oldTicks != _gameTicks) tickCondition.signalAll();

					runtime = (System.currentTimeMillis() - _gameStartTime) - runtime;

					// calculate sleep time... time needed to next tick minus time it takes to call moveObjects() 
					int sleepTime = 1 + MILLIS_IN_TICK - ((int) runtime) % MILLIS_IN_TICK;

					lock.unlock();
					sleep(sleepTime);
				}
			}
			catch (Exception e)
			{
				lock.unlock();
				_error = e;
			}
		}
	}

	class TimerWatcher implements Runnable
	{
		public void run()
		{
			if (!_timer.isAlive())
			{
				String time = (new SimpleDateFormat("HH:mm:ss")).format(new Date());
				_log.warning(time + " TimerThread stop with following error. restart it.");
				if (_timer._error != null) _timer._error.printStackTrace();

				_timer = new TimerThread();
				_timer.start();
			}
		}
	}

	/**
	 * Update the _knownObject and _knowPlayers of each L2Character that finished its movement and of their already known L2Object then notify AI with EVT_ARRIVED.<BR><BR>
	 */
	class MovingObjectArrived implements Runnable
	{
		private final L2Character _ended;

		MovingObjectArrived(L2Character ended)
		{
			_ended = ended;
		}

		public void run()
		{
			_ended.getKnownList().updateKnownObjects();
			if (_ended.hasAI())
				_ended.getAI().notifyEvent(CtrlEvent.EVT_ARRIVED);
		}
	}

	/**
	 * @param rise
	 */
	class BroadcastSunState implements Runnable
	{
		public void run()
		{
			int h = (getGameTime() / 60) % 24; // Time in hour
			boolean tempIsNight = (h < 6);
            
			if (tempIsNight != _isNight) { // If diff day/night state
                _isNight = tempIsNight; // Set current day/night varible to value of temp varible
                
                DayNightSpawnManager.getInstance().notifyChangeMode();
            }
		}
	}
}