/**
 * 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;

/**
 * RTCP packets for Receiver Reports
 * 
 * @author Arne Kepp
 */
public class RtcpPktRR extends RtcpPkt {
	/** Array of participants to send Receiver Reports to */
	protected Participant[] reportees = null;
	/** SSRC of participants the reports are for */
	protected long[] reporteeSsrc = null;// -1; //32 bits
	/** Fraction (over 256) of packets lost */
	protected int[] lossFraction = null;// -1; //8 bits
	/** Number of lost packets */
	protected int[] lostPktCount = null;// -1; //24 bits
	/** Extended highest sequence received */
	protected long[] extHighSeqRecv = null;// -1; //32 bits
	/** Interarrival jitter */
	protected long[] interArvJitter = null;// -1; //32 bits
	/** Middle 32 bits of NTP when last SR was received */
	protected long[] timeStampLSR = null;// -1; //32 bits
	/** Delay on last SRC */
	protected long[] delaySR = null;// -1; //32 bits

	/**
	 * Constructor for a packet with receiver reports
	 * 
	 * @param reportees
	 *            the participants on which to generate reports
	 * @param ssrc
	 *            the SSRC of the sender, from the RTPSession
	 */
	protected RtcpPktRR(Participant[] reportees, long ssrc) {
		super.packetType = 201;
		// Fetch all the right stuff from the database
		super.ssrc = ssrc;
		this.reportees = reportees;
	}

	/**
	 * 
	 * 
	 * If rcount < 0 we assume we have to parse the entire packet, otherwise
	 * we'll just parse the receiver report blocks (ie. the data came from a
	 * Sender Report packet)
	 * 
	 * @param aRawPkt
	 *            the byte[] with the report(s)
	 * @param start
	 *            where in the raw packet to start reading
	 * @param rrCount
	 *            the number of receiver reports, -1 if this does not come from
	 *            an SR
	 */
	protected RtcpPktRR(byte[] aRawPkt, int start, int rrCount) {
		// System.out.println("RtcpPktRR: " + rrCount + "  start: " + start);
		super.rawPkt = aRawPkt;

		if (rrCount < 0
				&& (!super.parseHeaders(start) || packetType != 201 || super.length < 1)) {
			if (RTPSession.rtpDebugLevel > 2) {
				System.out
						.println(" <-> RtcpPktRR.parseHeaders() etc. problem: "
								+ (!super.parseHeaders(start)) + " "
								+ packetType + " " + super.length);
			}
			super.problem = -201;
		}

		int base;
		if (rrCount > 0) {
			base = start + 28;
		} else {
			base = start + 8;
			rrCount = super.itemCount;
			super.ssrc = StaticProcs.bytesToUIntLong(aRawPkt, start + 4);
		}

		if (rrCount > 0) {
			reporteeSsrc = new long[rrCount];
			lossFraction = new int[rrCount];
			lostPktCount = new int[rrCount];
			extHighSeqRecv = new long[rrCount];
			interArvJitter = new long[rrCount];
			timeStampLSR = new long[rrCount];
			delaySR = new long[rrCount];

			for (int i = 0; i < rrCount; i++) {
				int pos = base + i * 24;
				reporteeSsrc[i] = StaticProcs.bytesToUIntLong(aRawPkt, pos);
				lossFraction[i] = (int) aRawPkt[pos + 4];
				aRawPkt[pos + 4] = (byte) 0;
				lostPktCount[i] = (int) StaticProcs.bytesToUIntLong(aRawPkt,
						pos + 4);
				extHighSeqRecv[i] = StaticProcs.bytesToUIntLong(aRawPkt,
						pos + 8);
				interArvJitter[i] = StaticProcs.bytesToUIntLong(aRawPkt,
						pos + 12);
				timeStampLSR[i] = StaticProcs
						.bytesToUIntLong(aRawPkt, pos + 16);
				delaySR[i] = StaticProcs.bytesToUIntLong(aRawPkt, pos + 20);
			}
		}
	}

	/**
	 * Encode the packet into a byte[], saved in .rawPkt
	 * 
	 * CompRtcpPkt will call this automatically
	 */
	protected void encode() {
		if (RTPSession.rtpDebugLevel > 9) {
			System.out.println("  -> RtcpPktRR.encode()");
		}

		byte[] rRs = null;
		// Gather up the actual receiver reports
		if (this.reportees != null) {
			rRs = this.encodeRR();
			super.rawPkt = new byte[rRs.length + 8];
			System.arraycopy(rRs, 0, super.rawPkt, 8, rRs.length);
			super.itemCount = reportees.length;
		} else {
			super.rawPkt = new byte[8];
			super.itemCount = 0;
		}

		// Write the common header
		super.writeHeaders();

		// Add our SSRC (as sender)
		StaticProcs.uIntLongToByteWord(super.ssrc, super.rawPkt, 4);

		if (RTPSession.rtpDebugLevel > 9) {
			System.out.println("  <- RtcpPktRR.encode()");
		}

	}

	/**
	 * Encodes the individual Receiver Report blocks,
	 * 
	 * so they can be used either in RR packets or appended to SR
	 * 
	 * @return the encoded packets
	 */
	protected byte[] encodeRR() {
		if (RTPSession.rtpDebugLevel > 10) {
			System.out.println("   -> RtcpPktRR.encodeRR()");
		}
		// assuming we will always create complete reports:
		byte[] ret = new byte[24 * reportees.length];

		// Write SR stuff
		for (int i = 0; i < reportees.length; i++) {
			int offset = 24 * i;
			StaticProcs.uIntLongToByteWord(reportees[i].ssrc, ret, offset);

			// Cumulative number of packets lost
			StaticProcs.uIntLongToByteWord(reportees[i]
					.getLostPktCount(), ret, 4 + offset);

			// Write Cumulative number of packets lost and loss fraction to
			// packet:
			System.arraycopy(reportees[i].getFractionLost(), 0, ret, 4 + offset, 1);

			// Extended highest sequence received
			StaticProcs.uIntLongToByteWord(reportees[i]
					.getExtHighSeqRecv(), ret, 8 + offset);

			// Interarrival jitter
			if (reportees[i].interArrivalJitter >= 0) {
				StaticProcs
						.uIntLongToByteWord((long) reportees[i].interArrivalJitter, ret, 12 + offset);
			} else {
				StaticProcs.uIntLongToByteWord(0, ret, 12 + offset);
			}

			// Timestamp last sender report received
			StaticProcs
					.uIntLongToByteWord(reportees[i].timeStampLSR, ret, 16 + offset);

			// Delay since last sender report received, in terms of 1/655536 s =
			// 0.02 ms
			if (reportees[i].timeReceivedLSR > 0) {
				StaticProcs.uIntLongToByteWord(reportees[i]
						.delaySinceLastSR(), ret, 20 + offset);
			} else {
				StaticProcs.uIntLongToByteWord(0,ret, 20 + offset);
			}
		}
		if (RTPSession.rtpDebugLevel > 10) {
			System.out.println("   <- RtcpPktRR.encodeRR()");
		}
		return ret;
	}

	/**
	 * Debug purposes only
	 */
	public void debugPrint() {
		System.out.println("RtcpPktRR.debugPrint() ");
		if (reportees != null) {
			for (int i = 0; i < reportees.length; i++) {
				Participant part = reportees[i];
				System.out.println("     part.ssrc: " + part.ssrc
						+ "  part.cname: " + part.cname);
			}
		} else {
			for (int i = 0; i < reporteeSsrc.length; i++) {
				System.out.println("     reporteeSSRC: " + reporteeSsrc[i]
						+ "  timeStampLSR: " + timeStampLSR[i]);
			}
		}
	}
}