/**
 * 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 Sender Reports 
 * 
 * @author Arne Kepp
 */
public class RtcpPktSR extends RtcpPkt {
	/** NTP timestamp, MSB */
	protected long ntpTs1 = -1; //32 bits
	/** NTP timestamp, LSB */
	protected long ntpTs2 = -1; //32 bits
	/** RTP timestamp */
	protected long rtpTs = -1; //32 bits
	/** Senders packet count */
	protected long sendersPktCount = -1; //32 bits
	/** Senders octet count */
	protected long sendersOctCount = -1; //32 bits
	/** RR packet with receiver reports that we can append */
	protected RtcpPktRR rReports = null;
	
	/**
	 * Constructor for a new Sender Report packet
	 * 
	 * @param ssrc the senders SSRC, presumably from RTPSession
	 * @param pktCount packets sent in this session
	 * @param octCount octets sent in this session
	 * @param rReports receiver reports, as RR packets, to be included in this packet
	 */
	protected RtcpPktSR(long ssrc, long pktCount, long octCount, RtcpPktRR rReports) {
		// Fetch all the right stuff from the database
		super.ssrc = ssrc;
		super.packetType = 200;
		sendersPktCount = pktCount;
		sendersOctCount = octCount;
		this.rReports = rReports;
	}
	
	/**
	 * Constructor that parses a received packet
	 * 
	 * @param aRawPkt the raw packet
	 * @param start the position at which SR starts
	 * @param length used to determine number of included receiver reports
	 */
	protected RtcpPktSR(byte[] aRawPkt, int start, int length) {
		if(RTPSession.rtpDebugLevel > 9) {
				System.out.println("  -> RtcpPktSR(rawPkt)");
		}
		
		super.rawPkt = aRawPkt;

		if(!super.parseHeaders(start) || packetType != 200 ) {
			if(RTPSession.rtpDebugLevel > 2) {
				System.out.println(" <-> RtcpPktSR.parseHeaders() etc. problem: "+ (!super.parseHeaders(start) ) + " " + packetType + " " + super.length);
			}
			super.problem = -200;
		} else {
			super.ssrc = StaticProcs.bytesToUIntLong(aRawPkt,4+start);
			if(length > 11)
				ntpTs1 = StaticProcs.bytesToUIntLong(aRawPkt,8+start);
			if(length > 15)
				ntpTs2 = StaticProcs.bytesToUIntLong(aRawPkt,12+start);
			if(length > 19)
				rtpTs = StaticProcs.bytesToUIntLong(aRawPkt,16+start);
			if(length > 23)
				sendersPktCount = StaticProcs.bytesToUIntLong(aRawPkt,20+start);
			if(length > 27)
				sendersOctCount = StaticProcs.bytesToUIntLong(aRawPkt,24+start);
			
			// RRs attached?
			if(itemCount > 0) {
				rReports = new RtcpPktRR(rawPkt,start,itemCount);
			}
		}
		
		if(RTPSession.rtpDebugLevel > 9) {
			System.out.println("  <- RtcpPktSR(rawPkt)");
		}
	}
	
	/**
	 * Encode the packet into a byte[], saved in .rawPkt
	 * 
	 * CompRtcpPkt will call this automatically
	 */
	protected void encode() {		
		if(RTPSession.rtpDebugLevel > 9) {
			if(this.rReports != null) {
				System.out.println("  -> RtcpPktSR.encode() receptionReports.length: " + this.rReports.length );
			} else {
				System.out.println("  -> RtcpPktSR.encode() receptionReports: null");
			}
		}
		
		if(this.rReports != null) {
			super.itemCount = this.rReports.reportees.length;
						
			byte[] tmp = this.rReports.encodeRR();
			super.rawPkt = new byte[tmp.length+28];
			//super.length = (super.rawPkt.length / 4) - 1;
			
			System.arraycopy(tmp, 0, super.rawPkt, 28, tmp.length);
			
		} else {
			super.itemCount = 0;
			super.rawPkt = new byte[28];
			//super.length = 6;
		}
		//Write the common header
		super.writeHeaders();
		
		// Convert to NTP and chop up
		long timeNow = System.currentTimeMillis();
		ntpTs1 = 2208988800L + (timeNow/1000);
		long ms = timeNow % 1000;
		double tmp = ((double)ms) / 1000.0;
		tmp = tmp * (double)4294967295L;
		ntpTs2 = (long) tmp;
		rtpTs = System.currentTimeMillis();
		
		//Write SR stuff
		byte[] someBytes;
		someBytes = StaticProcs.uIntLongToByteWord(super.ssrc);
		System.arraycopy(someBytes, 0, super.rawPkt, 4, 4);
		someBytes = StaticProcs.uIntLongToByteWord(ntpTs1);
		System.arraycopy(someBytes, 0, super.rawPkt, 8, 4);
		someBytes = StaticProcs.uIntLongToByteWord(ntpTs2);
		System.arraycopy(someBytes, 0, super.rawPkt, 12, 4);
		someBytes = StaticProcs.uIntLongToByteWord(rtpTs);
		System.arraycopy(someBytes, 0, super.rawPkt, 16, 4);
		someBytes = StaticProcs.uIntLongToByteWord(sendersPktCount);
		System.arraycopy(someBytes, 0, super.rawPkt, 20, 4);
		someBytes = StaticProcs.uIntLongToByteWord(sendersOctCount);
		System.arraycopy(someBytes, 0, super.rawPkt, 24, 4);
		
		if(RTPSession.rtpDebugLevel > 9) {
			System.out.println("  <- RtcpPktSR.encode() ntpTs1: "
					+ Long.toString(ntpTs1) + " ntpTs2: " + Long.toString(ntpTs2));
		}
	}

	/**
	 * Debug purposes only
	 */
	public void debugPrint() {
		System.out.println("RtcpPktSR.debugPrint() ");
		System.out.println("  SSRC:"+Long.toString(super.ssrc) +" ntpTs1:"+Long.toString(ntpTs1)
				+" ntpTS2:"+Long.toString(ntpTs2)+" rtpTS:"+Long.toString(rtpTs)
				+" senderPktCount:"+Long.toString(sendersPktCount)+" sendersOctetCount:"
				+Long.toString(sendersOctCount));
		if(this.rReports != null) {
			System.out.print("  Part of Sender Report: ");	
			this.rReports.debugPrint();
			System.out.println("  End Sender Report");
		} else {
			System.out.println("No Receiver Reports associated with this Sender Report.");
		}
	}
}