/**

 * Java RTP Library (jlibrtp)

 * Copyright (C) 2006 Arne Kepp

 * 

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 * 

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 */

package jlibrtp;

import java.io.IOException;

import java.net.DatagramPacket;

import java.net.InetSocketAddress;

/**

 * The RTP receiver thread waits on the designated UDP socket for new packets.

 * 

 * Once one arrives, it is parsed and tested. We also check the ip-address of the sender. 

 * If accepted, the packet is added onto the packet buffer of the participant.

 * 

 * A separate thread moves the packet from the packet buffer to the application.

 * 

 * @author Arne Kepp

 */

public class RTPReceiverThread extends Thread {

	/** Parent RTP Session */

	RTPSession rtpSession = null;

	RTPReceiverThread(RTPSession session) {

		rtpSession = session;

		if(RTPSession.rtpDebugLevel > 1) {

			System.out.println("<-> RTPReceiverThread created");

		} 

	}

	public void run() {

		if(RTPSession.rtpDebugLevel > 1) {

			if(rtpSession.mcSession) {

				System.out.println("-> RTPReceiverThread.run() starting on MC " + rtpSession.rtpMCSock.getLocalPort() );

			} else {

				System.out.println("-> RTPReceiverThread.run() starting on " + rtpSession.rtpSock.getLocalPort() );

			}

		}

		while(!rtpSession.endSession) {

			if(RTPSession.rtpDebugLevel > 6) {

				if(rtpSession.mcSession) {

					System.out.println("-> RTPReceiverThread.run() waiting for MC packet on " + rtpSession.rtpMCSock.getLocalPort() );

				} else {

					System.out.println("-> RTPReceiverThread.run() waiting for packet on " + rtpSession.rtpSock.getLocalPort() );

				}

			}

			// Prepare a packet

			byte[] rawPkt = new byte[1500];

			DatagramPacket packet = new DatagramPacket(rawPkt, rawPkt.length);

			// Wait for it to arrive

			if(! rtpSession.mcSession) {

				//Unicast

				try {

					rtpSession.rtpSock.receive(packet);

				} catch (IOException e) {

					if(!rtpSession.endSession) {

						e.printStackTrace();

					} else {

						continue;

					}

				}

			} else {

				//Multicast 

				try {

					rtpSession.rtpMCSock.receive(packet);

				} catch (IOException e) {

					if(!rtpSession.endSession) {

						e.printStackTrace();

					} else {

						continue;

					}

				}

			}

			// Parse the received RTP (?) packet

			RtpPkt pkt = new RtpPkt(rawPkt, packet.getLength());

			// Check whether it was valid.

			if(pkt == null) {

				System.out.println("Received invalid RTP packet. Ignoring");

				continue;

			}

			long pktSsrc = pkt.getSsrc();

			// Check for loops and SSRC collisions

			if( rtpSession.ssrc == pktSsrc )

				rtpSession.resolveSsrcConflict();

			long[] csrcArray = pkt.getCsrcArray();

			if( csrcArray != null) {

				for(int i=0; i< csrcArray.length; i++) {

					if(csrcArray[i] == rtpSession.ssrc);

						rtpSession.resolveSsrcConflict();

				}

			}

			if(RTPSession.rtpDebugLevel > 17) {

				System.out.println("-> RTPReceiverThread.run() rcvd packet, seqNum " + pktSsrc );

				if(RTPSession.rtpDebugLevel > 10) {

					String str = new String(pkt.getPayload());

					System.out.println("-> RTPReceiverThread.run() payload is " + str );

				}

			}

			//Find the participant in the database based on SSRC

			Participant part = rtpSession.partDb.getParticipant(pktSsrc);

			if(part == null) {

				InetSocketAddress nullSocket = null;

				part = new Participant((InetSocketAddress) packet.getSocketAddress(), nullSocket, pkt.getSsrc());

				part.unexpected = true;

				rtpSession.partDb.addParticipant(1,part);

			}

			// Do checks on whether the datagram came from the expected source for that SSRC.

			if(part.rtpAddress == null || packet.getAddress().equals(part.rtpAddress.getAddress())) {

				PktBuffer pktBuffer = part.pktBuffer;

				if(pktBuffer != null) {

					//A buffer already exists, append to it

					pktBuffer.addPkt(pkt);

				} else {

					// Create a new packet/frame buffer

					pktBuffer = new PktBuffer(this.rtpSession, part,pkt);

					part.pktBuffer = pktBuffer;

				}

			} else {

				System.out.println("RTPReceiverThread: Got an unexpected packet from " + pkt.getSsrc() 

						+ " the sending ip-address was " + packet.getAddress().toString() 

						+ ", we expected from " + part.rtpAddress.toString());

			}

			// Statistics for receiver report.

			part.updateRRStats(packet.getLength(), pkt);

			// Upate liveness

			part.lastRtpPkt = System.currentTimeMillis();

			if(RTPSession.rtpDebugLevel > 5) {

				System.out.println("<-> RTPReceiverThread signalling pktBufDataReady");

			}

			// Signal the thread that pushes data to application

			rtpSession.pktBufLock.lock();

			try { rtpSession.pktBufDataReady.signalAll(); } finally {

				rtpSession.pktBufLock.unlock();

			}

		}

	}

}