/*
 * Copyright (C) 2005 Luca Veltri - University of Parma - Italy
 * Copyright (C) 2009 The Sipdroid Open Source Project
 * 
 * This file is part of MjSip (http://www.mjsip.org)
 * 
 * MjSip is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * MjSip 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with MjSip; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * 
 * Author(s):
 * Luca Veltri (luca.veltri@unipr.it)
 */

package org.zoolu.sip.provider;

import org.zoolu.net.*;
import org.zoolu.sip.message.Message;
import java.io.IOException;

/**
 * UdpTransport provides an UDP transport service for SIP.
 */
class UdpTransport implements Transport, UdpProviderListener {
	/** UDP protocol type */
	public static final String PROTO_UDP = "udp";

	/** UDP provider */
	UdpProvider udp_provider;

	/** The protocol type */
	String proto;

	/** Transport listener */
	TransportListener listener;
	int port; // modified
	
	/** Creates a new UdpTransport */
	public UdpTransport(int port, TransportListener listener)
			throws IOException {
		this.listener = listener;
		UdpSocket socket = new UdpSocket(port);
		udp_provider = new UdpProvider(socket, this);
		this.port = socket.getLocalPort();
	}

	/** Creates a new UdpTransport */
	public UdpTransport(int port, IpAddress ipaddr, TransportListener listener)
			throws IOException {
		this.listener = listener;
		UdpSocket socket = new UdpSocket(port, ipaddr);
		udp_provider = new UdpProvider(socket, this);
		this.port = socket.getLocalPort();
	}

	/** Creates a new UdpTransport */
	public UdpTransport(UdpSocket socket, TransportListener listener) {
		this.listener = listener;
		udp_provider = new UdpProvider(socket, this);
		this.port = socket.getLocalPort();
	}

	/** Gets protocol type */
	public String getProtocol() {
		return PROTO_UDP;
	}

	public int getPort() {
		return port;
	}
	
	/** Sends a Message to a destination address and port */
	public void sendMessage(Message msg, IpAddress dest_ipaddr, int dest_port)
			throws IOException {
		if (udp_provider != null) {
			byte[] data = msg.toString().getBytes();
			UdpPacket packet = new UdpPacket(data, data.length);
			packet.setIpAddress(dest_ipaddr);
			packet.setPort(dest_port);
			udp_provider.send(packet);
		}
	}

	/** Stops running */
	public void halt() {
		if (udp_provider != null)
			udp_provider.halt();
	}

	/** Gets a String representation of the Object */
	public String toString() {
		if (udp_provider != null)
			return udp_provider.toString();
		else
			return null;
	}

	// ************************* Callback methods *************************

	/** When a new UDP datagram is received. */
	public void onReceivedPacket(UdpProvider udp, UdpPacket packet) {
		Message msg = new Message(packet);
		msg.setRemoteAddress(packet.getIpAddress().toString());
		msg.setRemotePort(packet.getPort());
		msg.setTransport(PROTO_UDP);
		if (listener != null)
			listener.onReceivedMessage(this, msg);
	}

	/** When DatagramService stops receiving UDP datagrams. */
	public void onServiceTerminated(UdpProvider udp, Exception error) {
		if (listener != null)
			listener.onTransportTerminated(this, error);
		UdpSocket socket = udp.getUdpSocket();
		if (socket != null)
			try {
				socket.close();
			} catch (Exception e) {
			}
		this.udp_provider = null;
		this.listener = null;
	}

}
