//package server;

import java.util.Hashtable;
import java.net.ServerSocket;
import java.net.Socket;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;

import java.io.IOException;

import java.util.Vector;

public class CWIcqServerEngine extends CConnectionKeeper{

	// Ther can be only one serve, though, variuos server interfaces.
	// So I choosed to MakeIt a Singleton !
	private static CWIcqServerEngine instance = null;

	// User Manager Class to Control All users
	protected CUserManager	userManager	= null;

	// Default contructor
	// But also it Can not be instanciated by others
	// so It is protected !! can only be instanciated by the GetInstance Method
	// As you see my dear teacher a DO know a lot of things about OO : ) !!
	// REMARK:: it can be private but in this case, it will not be Instanciated by Derivated Calasses !!
	protected CWIcqServerEngine() {
		// ..
		super(); // Call CConnection Keeper
		userManager = CUserManager.getInstance();
	}

	public static CWIcqServerEngine getInstance() {
		if ( instance == null ) {
			instance = new CWIcqServerEngine();
		}
		return instance;
	}

	// Start Socket Service
	public boolean startServer() {
		checkConnection ();
		try
		{
			System.out.println("Starting Server: " + getHostName() + ": " + getPort() );

			// Raise Servaer Tracking system ..
			new CServerStatusTracker	().start();

			while (listening) {
				// accept pass to Server Listener ..
				new CServerListener( accept() ).start(); // So here a thread stay listening ...
			}
			// Close Server Connection
			socketServer.close();
			return true;
		} catch (IOException ex) {
			System.out.println("deu merda no Start Server" + ex.getMessage());
			ex.printStackTrace();
			if (listening) {
				startServer();
			}
		}
		return false;
	}

	public synchronized boolean requestLogin(int userId) {
		sendMessage(CServerMessageManager.getServerRequestLoginMessage(userId));
		return true;
	}

	// this is used to Server to send a message to a given user or store the massage on his message queue
	public synchronized boolean sendMessage(CMessage msg) {
		try {
			CUser user = null;
			user = userManager.getUser( msg.getUserTo() );
			if (user == null) return false;
			if ( user.isUserOnline() ) {
				user.getOutputStream().writeObject(new CMessage(msg));
				user.getOutputStream().flush();
				return true;
			} else {
				// if was the server trying to send message ..
				if (msg.getUserFrom() == CServerMessageManager.MESSAGE_FROM_SERVER ) {
					return false;
				}
				user = userManager.getUser(msg.getUserFrom());
				if (user == null) { 
					return false; 
				}
				if (user.isUserOnline()) {
					user.getOutputStream().writeObject( CServerMessageManager.getOfflineMessage(user.getId()) );
					user.getOutputStream().flush();
				}
				userManager.saveOfflineMessage(msg.getUserFrom(),msg.getUserTo(),msg.getContent());
				return true;
			}
		} catch(IOException  ex) {
			ex.printStackTrace();
		} catch (Exception ex){
			ex.printStackTrace();
		}
		return false;
	}

	public synchronized boolean sendGlobalMessage(CMessage msg) {
		try {
			CUser user = null;
			System.out.println("GLOBAL MESSAGE");
			Vector temp = userManager.getAllUsers();
			for (int i=0; i < temp.size();i++) {
				user = (CUser)temp.elementAt(i) ;
				if (user != null) {
					if (user.isUserOnline()) {
						user.getOutputStream().writeObject(msg);
						user.getOutputStream().flush();
					}
				} else {
					return false;
				}
			}
			return true;
		} catch(IOException  ex) {
			ex.printStackTrace();
		} catch (Exception ex){
			ex.printStackTrace();
		}
		return false;
	}

	public synchronized CUser loginUser(CMessage msg , CUser client) {
		try {
			ObjectOutputStream userOutput = client.getOutputStream();
			ObjectInputStream userInput   = client.getInputStream();
			CUser aRegUSer  = userManager.getUser(msg.getUserFrom());
			if (aRegUSer == null) {
				System.out.println("[Server]:Invalid USer");
				userOutput.writeObject( CServerMessageManager.getLoginFailedMessage( client.getId() ));
				userOutput.flush();
				userOutput.writeObject( CServerMessageManager.getServerRequestLoginMessage( client.getId() ));
				userOutput.flush();
				return null; 
			}
			aRegUSer.setUserOnline();
			aRegUSer.setOutputStream(userOutput);
			aRegUSer.setInputStream(userInput);
			aRegUSer.setSocket(client.getSocket());
			aRegUSer.getOutputStream().writeObject(CServerMessageManager.getLoginSuccessfulMessage( aRegUSer.getId() ));
			aRegUSer.getOutputStream().flush();
			System.out.println("user logged (id):" + aRegUSer.getId() );
			return aRegUSer;
		} catch (IOException ex) {
			ex.printStackTrace();
		}
		return null;
	}
	public synchronized void logoutUser(CMessage msg) {
		try {
			CUser aRegUSer  = userManager.getUser(msg.getUserFrom());
			aRegUSer.setUserOffLine();
			aRegUSer.getOutputStream().writeObject(CServerMessageManager.getCloseConnectionMessage( aRegUSer.getId() ));
			aRegUSer.getOutputStream().flush();
			aRegUSer.getOutputStream().close();
			aRegUSer.getInputStream().close();
			aRegUSer.getSocket().close();
		} catch(IOException ex){
			//ex.printStackTrace();
			System.out.println("User Id: " + msg.getUserFrom() + "  has gone offline" );
		}
	}
	public synchronized void logoutUser(CUser client) {
		try {
			client.setUserOffLine();
			client.getOutputStream().writeObject(CServerMessageManager.getCloseConnectionMessage( client.getId() ));
			client.getOutputStream().close();
			client.getInputStream().close();
			client.getSocket().close();
		} catch(IOException ex) {
			//ex.printStackTrace();
			System.out.println("User Id: " + client.getId() + "  has gone offline" );
		}
	}

	public synchronized CUser createNewLogin(CUser user) {
		CUser p_user = null;
		if (CUserManager.getInstance().isUserExists(user.getId())) {
			p_user = userManager.createUser(user);
		}
		return p_user;
	}

	public synchronized Vector getOnlineFriends (int clientId ){
		CUserManager p_UserManager = CUserManager.getInstance();
		CUser user = null;
		// OBS friends is comming only with a valid Id for a while
		Vector friends = p_UserManager.getUserFriends(clientId);
		Vector onlineFriends = new Vector();
		for (int offset =0 ; offset < friends.size() ;offset++){
			user = p_UserManager.getUser( ((CUser)friends.elementAt(offset)).getId() );
			if (user.isUserOnline() ) {
				onlineFriends.addElement(user);
			}
		}
		return onlineFriends;
	}	
}