package grafikchat.model;

import grafikchat.ohmlogger.OhmLogger;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Observable;
import java.util.Observer;
import java.util.logging.Logger;

/**
 * TCP Server
 * 
 * @author marian
 */
public class Server extends Observable implements Runnable, Transceiver
{
    private int port;
    private ServerSocket server;
    private Socket client;
    private static Logger logger = OhmLogger.getLogger();
    private ObjectInputStream reader;
    private ObjectOutputStream writer;
    private volatile boolean ready;
    private Thread thd;
    
    /**
     * Constructor, initialize variables
     * @param port Port to listen on
     */
    public Server(int port)
    {
        this.port = port;
        this.server = null;
        this.client = null;
        this.reader = null;
        this.writer = null;
        this.ready = false;
        this.thd = null;
    }
    
    /**
     * Init server if not already done
     */
    @Override
    public void init()
    {
        if (thd == null) {
            thd = new Thread(this);
            thd.start();
        }
    }

    /**
     * Add observer to server
     * @param o Observer to add
     */
    @Override
    public void registerObserver(Observer o)
    {
        this.addObserver(o);
    }
    
    /**
     * Run server in thread
     */
    @Override
    public void run()
    {
        logger.info("Running server...");
        
        while (true)
        {
            if (server == null) {
                try {
                    server = new ServerSocket(port);  
                } catch (IOException e) {
                    logger.severe(e.toString());
                    return;
                }
                
                logger.info("Waiting for client to connect");
                try {
                    client = server.accept();
                } catch (IOException e) {
                    logger.severe(e.toString());
                    return;
                }
                logger.info("Client connected");
                
                try {
                    writer = new ObjectOutputStream(client.getOutputStream());
                } catch (IOException e) {
                    logger.severe(e.toString());
                    return;
                }
                
                try {
                    reader = new ObjectInputStream(client.getInputStream());
                } catch (IOException e) {
                    logger.severe(e.toString());
                    return;
                }
                
                ready = true;
                
            }
            
            if (ready) {
                try {
                    //logger.info("Waiting for message");
                    
                    Object o = reader.readObject();
                    
                    if (o == null) {
                        logger.warning("Reached end of stream");
                        ready = false;
                        continue;
                    }
                    
                    this.setChanged();
                    this.notifyObservers(o);
                } catch (ClassNotFoundException | IOException e) {
                    logger.severe(e.toString());
                    return;
                }
            }
        }
    }
    
    /**
     * Send message to client
     * @param d TransceiverData to transmit
     */
    @Override
    public void sendMessage(TransceiverData d)
    {
        if (ready) {
            try {
                writer.writeObject(d);
            } catch (IOException e) {
                logger.severe(e.toString());
            }
        } else {
            logger.warning("Server not ready to send message. Connect first");
        }
    }
    
}