/***********************************************************************************
* Copyright (c) 2015 /// Project SWG /// www.projectswg.com                        *
*                                                                                  *
* ProjectSWG is the first NGE emulator for Star Wars Galaxies founded on           *
* July 7th, 2011 after SOE announced the official shutdown of Star Wars Galaxies.  *
* Our goal is to create an emulator which will provide a server for players to     *
* continue playing a game similar to the one they used to play. We are basing      *
* it on the final publish of the game prior to end-game events.                    *
*                                                                                  *
* This file is part of Holocore.                                                   *
*                                                                                  *
* -------------------------------------------------------------------------------- *
*                                                                                  *
* Holocore is free software: you can redistribute it and/or modify                 *
* it under the terms of the GNU Affero General Public License as                   *
* published by the Free Software Foundation, either version 3 of the               *
* License, or (at your option) any later version.                                  *
*                                                                                  *
* Holocore 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 Affero General Public License for more details.                              *
*                                                                                  *
* You should have received a copy of the GNU Affero General Public License         *
* along with Holocore.  If not, see <http://www.gnu.org/licenses/>.                *
*                                                                                  *
***********************************************************************************/
package services.galaxy;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import network.packets.soe.Disconnect;
import network.packets.soe.Disconnect.DisconnectReason;
import network.packets.swg.zone.HeartBeatMessage;
import intents.CloseConnectionIntent;
import intents.GalacticPacketIntent;
import intents.PlayerEventIntent;
import resources.control.Intent;
import resources.control.Service;
import resources.player.Player;
import resources.player.PlayerEvent;
import resources.player.PlayerState;

public class ConnectionService extends Service {
	
	private static final double LD_THRESHOLD = TimeUnit.MINUTES.toMillis(3); // Time since last packet
	private static final double DISAPPEAR_THRESHOLD = TimeUnit.MINUTES.toMillis(2); // Time after the LD
	
	private final ScheduledExecutorService updateService;
	private final Runnable updateRunnable;
	private final Runnable disappearRunnable;
	private final Queue <Player> disappearPlayers;
	private final List <Player> zonedInPlayers;
	
	public ConnectionService() {
		updateService = Executors.newSingleThreadScheduledExecutor();
		zonedInPlayers = new LinkedList<Player>();
		disappearPlayers = new LinkedList<Player>();
		updateRunnable = new Runnable() {
			public void run() {
				synchronized (zonedInPlayers) {
					for (Player p : zonedInPlayers) {
						if (p.getTimeSinceLastPacket() > LD_THRESHOLD) {
							logOut(p);
							disconnect(p, DisconnectReason.TIMEOUT);
						}
					}
				}
			}
		};
		disappearRunnable = new Runnable() {
			public void run() {
				Player p = disappearPlayers.poll();
				synchronized (zonedInPlayers) {
					if (p != null && zonedInPlayers.contains(p))
						disappear(p);
				}
			}
		};
	}
	
	@Override
	public boolean initialize() {
		registerForIntent(PlayerEventIntent.TYPE);
		registerForIntent(GalacticPacketIntent.TYPE);
		return super.initialize();
	}
	
	@Override
	public boolean start() {
		updateService.scheduleAtFixedRate(updateRunnable, 10, 10, TimeUnit.SECONDS);
		return super.start();
	}
	
	@Override
	public boolean terminate() {
		updateService.shutdownNow();
		boolean success = false;
		try {
			success = updateService.awaitTermination(5, TimeUnit.SECONDS);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		return super.terminate() && success;
	}
	
	@Override
	public void onIntentReceived(Intent i) {
		if (i instanceof PlayerEventIntent) {
			if (((PlayerEventIntent)i).getEvent() == PlayerEvent.PE_ZONE_IN) {
				Player p = ((PlayerEventIntent)i).getPlayer();
				synchronized (zonedInPlayers) {
					removeOld(p);
					zonedInPlayers.add(p);
				}
			} else if (((PlayerEventIntent)i).getEvent() == PlayerEvent.PE_DISAPPEAR) {
				synchronized (zonedInPlayers) {
					zonedInPlayers.remove(((PlayerEventIntent)i).getPlayer());
				}
			}
		} else if (i instanceof GalacticPacketIntent) {
			if (((GalacticPacketIntent)i).getPacket() instanceof HeartBeatMessage) {
				GalacticPacketIntent gpi = (GalacticPacketIntent) i;
				Player p = gpi.getPlayerManager().getPlayerFromNetworkId(gpi.getNetworkId());
				if (p != null)
					p.sendPacket(gpi.getPacket());
			} else if (((GalacticPacketIntent)i).getPacket() instanceof Disconnect) {
				GalacticPacketIntent gpi = (GalacticPacketIntent) i;
				Player p = gpi.getPlayerManager().getPlayerFromNetworkId(gpi.getNetworkId());
				if (p != null) {
					logOut(p);
					disconnect(p, DisconnectReason.OTHER_SIDE_TERMINATED);
				}
			}
		}
	}
	
	private void removeOld(Player nPlayer) {
		synchronized (zonedInPlayers) {
			Iterator <Player> zonedIterator = zonedInPlayers.iterator();
			while (zonedIterator.hasNext()) {
				Player old = zonedIterator.next();
				if (old.equals(nPlayer)) {
					zonedIterator.remove();
					disconnect(old, DisconnectReason.NEW_CONNECTION_ATTEMPT);
				}
			}
		}
	}
	
	private void logOut(Player p) {
		if (p.getPlayerState() != PlayerState.LOGGED_OUT)
			System.out.println("[" + p.getUsername() +"] Logged out " + p.getCharacterName());
		p.setPlayerState(PlayerState.LOGGED_OUT);
		disappearPlayers.add(p);
		updateService.schedule(disappearRunnable, (long) DISAPPEAR_THRESHOLD, TimeUnit.MILLISECONDS);
	}
	
	private void disappear(Player p) {
		p.setPlayerState(PlayerState.DISCONNECTED);
		System.out.println("[" + p.getUsername() +"] " + p.getCharacterName() + " disappeared");
		new PlayerEventIntent(p, PlayerEvent.PE_DISAPPEAR).broadcast();
	}
	
	private void disconnect(Player player, DisconnectReason reason) {
		new CloseConnectionIntent(player.getConnectionId(), player.getNetworkId(), reason).broadcast();
	}
	
}