import java.io.IOException;
import java.net.InetAddress;
import java.net.DatagramSocket;
import java.net.MulticastSocket;
import java.net.DatagramPacket;
import java.net.SocketException;

import javax.media.protocol.DataSource;
import javax.media.protocol.PushSourceStream;
import javax.media.protocol.ContentDescriptor;
import javax.media.protocol.SourceTransferHandler;
import javax.media.rtp.RTPConnector;
import javax.media.rtp.OutputDataStream;


/**
 * An implementation of RTPConnector based on UDP sockets.
 */
public class RTPSocketAdapter implements RTPConnector {

    DatagramSocket dataSock;
    DatagramSocket ctrlSock;

    InetAddress addr;
    int port;

    SockInputStream dataInStrm = null, ctrlInStrm = null;
    SockOutputStream dataOutStrm = null, ctrlOutStrm = null;


    public RTPSocketAdapter(InetAddress addr, int port) throws IOException {
    this(addr, port, 1);
    }

    public RTPSocketAdapter(InetAddress addr, int port, int ttl) throws IOException {

    try {

        if (addr.isMulticastAddress()) {
        dataSock = new MulticastSocket(port);
        ctrlSock = new MulticastSocket(port+1);
        ((MulticastSocket)dataSock).joinGroup(addr);
        ((MulticastSocket)dataSock).setTimeToLive(ttl);
        ((MulticastSocket)ctrlSock).joinGroup(addr);
        ((MulticastSocket)ctrlSock).setTimeToLive(ttl);
        } else {
        dataSock = new DatagramSocket(port, InetAddress.getLocalHost());
        ctrlSock = new DatagramSocket(port+1, InetAddress.getLocalHost());
        }


    } catch (SocketException e) {
        throw new IOException(e.getMessage());
    }

    this.addr = addr;
    this.port = port;
    }

    /**
     * Returns an input stream to receive the RTP data. 
     */
    public PushSourceStream getDataInputStream() throws IOException {
    if (dataInStrm == null) {
        dataInStrm = new SockInputStream(dataSock, addr, port);
        dataInStrm.start();
    }
    return dataInStrm;
    }

    /**
     * Returns an output stream to send the RTP data.
     */
    public OutputDataStream getDataOutputStream() throws IOException {
    if (dataOutStrm == null)
        dataOutStrm = new SockOutputStream(dataSock, addr, port);
    return dataOutStrm;
    }

    /**
     * Returns an input stream to receive the RTCP data.
     */
    public PushSourceStream getControlInputStream() throws IOException {
    if (ctrlInStrm == null) {
        ctrlInStrm = new SockInputStream(ctrlSock, addr, port+1);
        ctrlInStrm.start();
    }
    return ctrlInStrm;
    }

    /**
     * Returns an output stream to send the RTCP data.
     */
    public OutputDataStream getControlOutputStream() throws IOException {
    if (ctrlOutStrm == null)
        ctrlOutStrm = new SockOutputStream(ctrlSock, addr, port+1);
    return ctrlOutStrm;
    }

    /**
     * Close all the RTP, RTCP streams.
     */
    public void close() {
    if (dataInStrm != null)
        dataInStrm.kill();
    if (ctrlInStrm != null)
        ctrlInStrm.kill();
    dataSock.close();
    ctrlSock.close();
    }

    /**
     * Set the receive buffer size of the RTP data channel.
     * This is only a hint to the implementation.  The actual implementation
     * may not be able to do anything to this.
     */
    public void setReceiveBufferSize( int size) throws IOException {
    dataSock.setReceiveBufferSize(size);
    }

    /**
     * Get the receive buffer size set on the RTP data channel.
     * Return -1 if the receive buffer size is not applicable for 
     * the implementation.
     */
    public int getReceiveBufferSize() {
    try {
        return dataSock.getReceiveBufferSize();
    } catch (Exception e) {
        return -1;
    }
    }

    /**
     * Set the send buffer size of the RTP data channel.
     * This is only a hint to the implementation.  The actual implementation
     * may not be able to do anything to this.
     */
    public void setSendBufferSize( int size) throws IOException {
    dataSock.setSendBufferSize(size);
    }

    /**
     * Get the send buffer size set on the RTP data channel.
     * Return -1 if the send buffer size is not applicable for 
     * the implementation.
     */
    public int getSendBufferSize() {
    try {
        return dataSock.getSendBufferSize();
    } catch (Exception e) {
        return -1;
    }
    }

    /**
     * Return the RTCP bandwidth fraction.  This value is used to
     * initialize the RTPManager.  Check RTPManager for more detauls.
     * Return -1 to use the default values.
     */
    public double getRTCPBandwidthFraction() {
    return -1;
    }

    /**
     * Return the RTCP sender bandwidth fraction.  This value is used to
     * initialize the RTPManager.  Check RTPManager for more detauls.
     * Return -1 to use the default values.
     */
    public double getRTCPSenderBandwidthFraction() {
    return -1;
    }


    /**
     * An inner class to implement an OutputDataStream based on UDP sockets.
     */
    class SockOutputStream implements OutputDataStream {

    DatagramSocket sock;
    InetAddress addr;
    int port;

    public SockOutputStream(DatagramSocket sock, InetAddress addr, int port) {
        this.sock = sock;
        this.addr = addr;
        this.port = port;
    }

    public int write(byte data[], int offset, int len) {
        try {
        sock.send(new DatagramPacket(data, offset, len, addr, port));
        } catch (Exception e) {
        return -1;
        }
        return len;
    }
    }


    /**
     * An inner class to implement an PushSourceStream based on UDP sockets.
     */
    class SockInputStream extends Thread implements PushSourceStream {

    DatagramSocket sock;
    InetAddress addr;
    int port;
    boolean done = false;
    boolean dataRead = false;

    SourceTransferHandler sth = null;

    public SockInputStream(DatagramSocket sock, InetAddress addr, int port) {
        this.sock = sock;
        this.addr = addr;
        this.port = port;
    }

    public int read(byte buffer[], int offset, int length) {
        DatagramPacket p = new DatagramPacket(buffer, offset, length, addr, port);
        try {
        sock.receive(p);
        } catch (IOException e) {
        return -1;
        }
        synchronized (this) {
        dataRead = true;
        notify();
        }
        return p.getLength();
    }

    public synchronized void start() {
        super.start();
        if (sth != null) {
        dataRead = true;
        notify();
        }
    }

    public synchronized void kill() {
        done = true;
        notify();
    }

    public int getMinimumTransferSize() {
        return 2 * 1024;    // twice the MTU size, just to be safe.
    }

    public synchronized void setTransferHandler(SourceTransferHandler sth) {
        this.sth = sth;
        dataRead = true;
        notify();
    }

    // Not applicable.
    public ContentDescriptor getContentDescriptor() {
        return null;
    }

    // Not applicable.
    public long getContentLength() {
        return LENGTH_UNKNOWN;
    }

    // Not applicable.
    public boolean endOfStream() {
        return false;
    }

    // Not applicable.
    public Object[] getControls() {
        return new Object[0];
    }

    // Not applicable.
    public Object getControl(String type) {
        return null;
    }

    /**
     * Loop and notify the transfer handler of new data.
     */
    public void run() {
        while (!done) {

        synchronized (this) {
            while (!dataRead && !done) {
            try {
                wait();
            } catch (InterruptedException e) { }
            }
            dataRead = false;
        }

        if (sth != null && !done) {
            sth.transferData(this);
        }
        }
    }
    }
}