/**
 * PacketReceivingThread.java
 */

package boondock.holdem.Network;

import java.io.*;
import java.net.*;
import java.util.*;
/**
 * Listens for DatagramPackets containing messages.
 *
 * @author  Jonathan O'Keefe
 * @author  Scott Semonian
 * @author  Matt Brinza
 * @author  Hamid R. Tahsildoost
 *
 * @author	The Boondock Saints
 * @author No Limit Texas Holdem
 */
public class PacketReceivingThread extends Thread {

  private MessageListener messageListener;
  private MulticastSocket multicastSocket;
  private InetAddress multicastGroup;
  private boolean keepListening = true;

 /**
  * PacketReceivingThread constructor.
  *
  * @param listener Sets the MessageListener to whom message should be delivered
  */
  public PacketReceivingThread( MessageListener listener ){
    super( "PacketReceivingThread" );

    messageListener = listener;

    try {
      multicastSocket = new MulticastSocket(constants.MULTICAST_LISTENING_PORT );
      multicastGroup = InetAddress.getByName(constants.MULTICAST_ADDRESS );
      multicastSocket.joinGroup( multicastGroup );
      multicastSocket.setSoTimeout( 5000 );
    }

    catch ( IOException ioException ) {
      System.out.println("IO Exception Occured in PacketReceivingThread");
      //ioException.printStackTrace();
    }

  } // end PacketReceivingThread constructor

 /**
  * Listen for new messages from the mutlicast group and fwd them to the MessageListener.
  * This function is NOT synchronized; causes hang on disconnect.
  */
  public void run(){
    while ( keepListening ) {
      byte[] buffer = new byte[ constants.MESSAGE_SIZE ];

      DatagramPacket packet = new DatagramPacket( buffer,constants.MESSAGE_SIZE );

      try {
        multicastSocket.receive( packet );
      }

      catch ( InterruptedIOException interruptedIOException ) {
		//System.out.println("InterruptedIOException Occured while running PacketReceivingThread");
        continue;
      }

      catch ( IOException ioException ) {
		System.out.println("IOException Occured while running PacketReceivingThread");
        //ioException.printStackTrace();
        break;
      }

      String message = new String( packet.getData() );

      message = message.trim();

      StringTokenizer tokenizer = new StringTokenizer(message, constants.MESSAGE_SEPARATOR );

      if ( tokenizer.countTokens() == 2 )

        messageListener.messageReceived(tokenizer.nextToken(),tokenizer.nextToken() ); // message body

    } // end while

    try {
		multicastSocket.leaveGroup( multicastGroup );
		multicastSocket.close();
    }

    catch ( IOException ioException ) {
		System.out.println("IOException Occured while running PacketReceivingThread (Multicast Socket)");
		//ioException.printStackTrace();
    }

  } // end method run

 /**
  * Stop listening for new messages.
  * This function is synchronized.
  */
  public synchronized void stopListening(){
    keepListening = false;
  }

} // end class PacketReceivingThread