/**

 * 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.util.*;

import java.net.InetSocketAddress;

/**

 * Compound RTCP packet class.

 * 

 * It basically holds a list of packets. This list can either be constructed

 * by providing a byte[] of a compound packet, or by adding individual packets.

 * 

 * Upon encode(), the packet will call encode on all the added packets.

 * 

 * problem == 0 indicates the parsing succeeded.

 * 

 * 

 * @author Arne Kepp

 */

public class CompRtcpPkt {

	/** Problem indicator, negative values denote packet type that cause problem */

	protected int problem = 0;

	/** Stores the different subclasses of RtcpPkt that make up the compound packet */

	protected LinkedList<RtcpPkt> rtcpPkts = new LinkedList<RtcpPkt>();

	/**

	 * Instantiates an empty Compound RTCP packet to which you can add RTCP packets

	 */

	protected CompRtcpPkt() {

		// Will have to add packets directly to rtcpPkts.

		if(RTPSession.rtpDebugLevel > 7) {

			System.out.println("<-> CompRtcpPkt()");

		}

	}

	/**

	 * Add a RTCP packet to the compound packet. Pakcets are added in order,

	 * so you have to ensure that a Sender Report or Receiver Report is 

	 * added first.

	 * 

	 * @param aPkt the packet to be added

	 */

	protected void addPacket(RtcpPkt aPkt) {

		if(RTPSession.rtpDebugLevel > 11) {

			System.out.println("  <-> CompRtcpPkt.addPacket( "+ aPkt.getClass() + " )");

		}

		if(aPkt.problem == 0) {

			rtcpPkts.add(aPkt);

		} else {

			this.problem = aPkt.problem;

		}

	}

	/**

	 * Picks a received Compound RTCP packet apart.

	 * 

	 * Only SDES packets are processed directly, other packets are

	 * parsed and put into aComptRtcpPkt.rtcpPkts, but not 

	 * 

	 * Check the aComptRtcpPkt.problem , if the value is non-zero

	 * the packets should probably be discarded.

	 * 

	 * @param rawPkt the byte array received from the socket

	 * @param packetSize the actual number of used bytes

	 * @param adr the socket address from which the packet was received

	 * @param rtpSession the RTPSession with the participant database

	 */

	protected CompRtcpPkt(byte[] rawPkt, int packetSize, InetSocketAddress adr, RTPSession rtpSession) {

		if(RTPSession.rtcpDebugLevel > 7) {

			System.out.println("-> CompRtcpPkt(" + rawPkt.getClass() + ", size " + packetSize + ", from " + adr.toString() + ", " + rtpSession.getClass() + ")");

		}

		//System.out.println("rawPkt.length:" + rawPkt.length + " packetSize:" + packetSize);

		// Chop it up

		int start = 0;

		while(start < packetSize && problem == 0) {

			int length = (StaticProcs.bytesToUIntInt(rawPkt, start + 2)) + 1;

			if(length*4 + start > rawPkt.length) {

				System.out.println("!!!! CompRtcpPkt.(rawPkt,..,..) length ("+ (length*4+start)

						+ ") exceeds size of raw packet ("+rawPkt.length+") !");

				this.problem = -3;

			}

			int pktType = (int) rawPkt[start + 1];

			if(pktType < 0) {

				pktType += 256;

			}

			if(start == 0) {

				// Compound packets need to start with SR or RR

				if(pktType != 200 && pktType != 201 ) {

					if(RTPSession.rtcpDebugLevel > 3) {

						System.out.println("!!!! CompRtcpPkt(rawPkt...) packet did not start with SR or RR");

					}

					this.problem = -1;

				}

				// Padding bit should be zero for the first packet

				if(((rawPkt[start] & 0x20) >>> 5) == 1) {

					if(RTPSession.rtcpDebugLevel > 3) {

						System.out.println("!!!! CompRtcpPkt(rawPkt...) first packet was padded");

					}

					this.problem = -2;

				}

			}

			//System.out.println("start: " + start + "   pktType: " + pktType + "  length:" + length );			

			if(pktType == 200) {

				addPacket(new RtcpPktSR(rawPkt,start,length*4));

			} else if(pktType == 201 ) {

				addPacket(new RtcpPktRR(rawPkt,start, -1));

			} else if(pktType == 202) {

				addPacket(new RtcpPktSDES(rawPkt,start, adr, rtpSession.partDb));

			} else if(pktType == 203 ) {

				addPacket(new RtcpPktBYE(rawPkt,start));

			} else if(pktType == 204) {

				addPacket(new RtcpPktAPP(rawPkt,start));

			} else if(pktType == 205) {

				addPacket(new RtcpPktRTPFB(rawPkt,start, rtpSession));

			} else if(pktType == 206) {

				addPacket(new RtcpPktPSFB(rawPkt,start,rtpSession));

			} else {

				System.out.println("!!!! CompRtcpPkt(byte[] rawPkt, int packetSize...) "

						+"UNKNOWN RTCP PACKET TYPE:" + pktType);

			}

			//System.out.println(" start:" + start + "  pktType:" + pktType + " length:" + length);

			start += length*4;

			if(RTPSession.rtcpDebugLevel > 12) {

				System.out.println(" start:"+start+"  parsing pktType "+pktType+" length: "+length);

			}

		}

		if(RTPSession.rtcpDebugLevel > 7) {

			System.out.println("<- CompRtcpPkt(rawPkt....)");

		}

	}

	/**

	 * Encode combines the RTCP packets in this.rtcpPkts into a byte[]

	 * by calling the encode() function on each of them individually.

	 * 

	 * The order of rtcpPkts is preserved, so a RR or SR packet must be first.

	 * 

	 * @return the trimmed byte[] representation of the packet, ready to go into a UDP packet.

	 */

	protected byte[] encode() {

		if(RTPSession.rtpDebugLevel > 9) {

			System.out.println(" <- CompRtcpPkt.encode()");

		}

		ListIterator<RtcpPkt>  iter = rtcpPkts.listIterator();

		byte[] rawPkt = new byte[1500];

		int index = 0;

		while(iter.hasNext()) {

			RtcpPkt aPkt = (RtcpPkt) iter.next();

			if(aPkt.packetType == 200) {

				RtcpPktSR pkt = (RtcpPktSR) aPkt;

				pkt.encode();

				System.arraycopy(pkt.rawPkt, 0, rawPkt, index, pkt.rawPkt.length);

				index += pkt.rawPkt.length;

			} else if(aPkt.packetType == 201 ) {

				RtcpPktRR pkt = (RtcpPktRR) aPkt;

				pkt.encode();

				System.arraycopy(pkt.rawPkt, 0, rawPkt, index, pkt.rawPkt.length);

				index += pkt.rawPkt.length;

			} else if(aPkt.packetType == 202) {

				RtcpPktSDES pkt = (RtcpPktSDES) aPkt;

				pkt.encode();

				//System.out.println(" ENCODE SIZE: " + pkt.rawPkt.length);

				System.arraycopy(pkt.rawPkt, 0, rawPkt, index, pkt.rawPkt.length);

				index += pkt.rawPkt.length;

			} else if(aPkt.packetType == 203) {

				RtcpPktBYE pkt = (RtcpPktBYE) aPkt;

				pkt.encode();

				System.arraycopy(pkt.rawPkt, 0, rawPkt, index, pkt.rawPkt.length);

				index += pkt.rawPkt.length;

			} else if(aPkt.packetType == 204) {

				RtcpPktAPP pkt = (RtcpPktAPP) aPkt;

				pkt.encode();

				System.arraycopy(pkt.rawPkt, 0, rawPkt, index, pkt.rawPkt.length);

				index += pkt.rawPkt.length;

			} else if(aPkt.packetType == 205) {

				RtcpPktRTPFB pkt = (RtcpPktRTPFB) aPkt;

				pkt.encode();

				System.arraycopy(pkt.rawPkt, 0, rawPkt, index, pkt.rawPkt.length);

				index += pkt.rawPkt.length;

			} else if(aPkt.packetType == 206) {

				RtcpPktPSFB pkt = (RtcpPktPSFB) aPkt;

				pkt.encode();

				System.arraycopy(pkt.rawPkt, 0, rawPkt, index, pkt.rawPkt.length);

				index += pkt.rawPkt.length;

			} else {

				System.out.println("CompRtcpPkt aPkt.packetType:" + aPkt.packetType);

			}

			//System.out.println(" packetType:" + aPkt.packetType + " length:" + aPkt.rawPkt.length + " index:" + index);

		} 

		byte[] output = new byte[index];

		System.arraycopy(rawPkt, 0, output, 0, index);

		if(RTPSession.rtpDebugLevel > 9) {

			System.out.println(" -> CompRtcpPkt.encode()");

		}

		return output;

	}

}