/**
 * 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.Enumeration;

/**
 * The purpose of this thread is to check whether there are packets ready from
 * any participants.
 * 
 * It should sleep when not in use, and be woken up by a condition variable.
 * 
 * Optionally, if we do jitter-control, the condition variable should have a max
 * waiting period equal to how often we need to push data.
 * 
 * @author Arne Kepp
 */
public class AppCallerThread extends Thread {
	/** The parent RTP Session */
	RTPSession rtpSession;
	/** The applications interface, where the callback methods are called */
	RTPAppIntf appl;

	/**
	 * Instatiates the AppCallerThread
	 * 
	 * @param session
	 *            the RTPSession with participants etc
	 * @param rtpApp
	 *            the interface to which data is given
	 */
	protected AppCallerThread(RTPSession session, RTPAppIntf rtpApp) {
		rtpSession = session;
		appl = rtpApp;
		if (RTPSession.rtpDebugLevel > 1) {
			System.out.println("<-> AppCallerThread created");
		}
	}

	/**
	 * The AppCallerThread will run in this loop until the RTPSession is
	 * terminated.
	 * 
	 * Whenever an RTP packet is received it will loop over the participants to
	 * check for packet buffers that have available frame.
	 */
	public void run() {
		if (RTPSession.rtpDebugLevel > 3) {
			System.out.println("-> AppCallerThread.run()");
		}

		while (rtpSession.endSession == false) {

			rtpSession.pktBufLock.lock();
			try {
				if (RTPSession.rtpDebugLevel > 4) {
					System.out.println("<-> AppCallerThread going to Sleep");
				}

				try {
					rtpSession.pktBufDataReady.await();
				} catch (Exception e) {
					System.out.println("AppCallerThread:" + e.getMessage());
				}

				// Next loop over all participants and check whether they have
				// anything for us.
				Enumeration<Participant> enu = rtpSession.partDb
				.getParticipants();

				while (enu.hasMoreElements()) {
					Participant p = enu.nextElement();

					boolean done = false;
					// System.out.println(p.ssrc + " " + !done +" " +
					// p.rtpAddress
					// + " " + rtpSession.naiveReception + " " + p.pktBuffer);
					// System.out.println("done: " + done + "  p.unexpected: " +
					// p.unexpected);
					while (!done
							&& (!p.unexpected || rtpSession.naiveReception)
							&& p.pktBuffer != null && p.pktBuffer.length > 0) {

						DataFrame aFrame = p.pktBuffer.popOldestFrame();
						if (aFrame == null) {
							done = true;
						} else {
							appl.receiveData(aFrame, p);
						}
					}
				}

			} finally {
				rtpSession.pktBufLock.unlock();
			}
		}
		if (RTPSession.rtpDebugLevel > 3) {
			System.out.println("<- AppCallerThread.run() terminating");
		}
	}

	public DataFrame getNextDataFrame() {
		if (RTPSession.rtpDebugLevel > 3) {
			System.out.println("-> AppCallerThread.run()");
		}
		//rtpSession.pktBufLock.lock();
		try {
			if (RTPSession.rtpDebugLevel > 4) {
				System.out.println("<-> AppCallerThread going to Sleep");
			}

			/*try {
				rtpSession.pktBufDataReady.await();
			} catch (Exception e) {
				System.out.println("AppCallerThread:" + e.getMessage());
			}*/

			// Next loop over all participants and check whether they have
			// anything for us.
			/*Enumeration<Participant> enu = rtpSession.partDb
			.getParticipants();

			while (enu.hasMoreElements()) {*/
				Participant p = rtpSession.firstPart;

				boolean done = false;
				// System.out.println(p.ssrc + " " + !done +" " +
				// p.rtpAddress
				// + " " + rtpSession.naiveReception + " " + p.pktBuffer);
				// System.out.println("done: " + done + "  p.unexpected: " +
				// p.unexpected);
				while (!done
						&& (!p.unexpected || rtpSession.naiveReception)
						&& p.pktBuffer != null && p.pktBuffer.length > 0) {

					DataFrame aFrame = p.pktBuffer.popOldestFrame();
					if (aFrame == null) {
						done = true;
					} else {
						return aFrame;
					}
				}
			//}

		} finally {
			//rtpSession.pktBufLock.unlock();
		}
		if (RTPSession.rtpDebugLevel > 3) {
			System.out.println("<- AppCallerThread.run() terminating");
		}
		return null;
	}

}