/*
 * 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.transaction;

import org.zoolu.sip.provider.*;
import org.zoolu.sip.message.*;
import org.zoolu.tools.Timer;
import org.zoolu.tools.LogLevel;

/**
 * Generic client transaction as defined in RFC 3261 (Section 17.1.2). A
 * TransactionClient is responsable to create a new SIP transaction, starting
 * with a request message sent through the SipProvider and ending with a final
 * response.<BR>
 * The changes of the internal status and the received messages are fired to the
 * TransactionListener passed to the TransactionClient object.<BR>
 */

public class TransactionClient extends Transaction {
	/**
	 * the TransactionClientListener that captures the events fired by the
	 * TransactionClient
	 */
	TransactionClientListener transaction_listener;

	/** retransmission timeout ("Timer E" in RFC 3261) */
	Timer retransmission_to;
	/** transaction timeout ("Timer F" in RFC 3261) */
	Timer transaction_to;
	/** clearing timeout ("Timer K" in RFC 3261) */
	Timer clearing_to;

	/** Costructs a new TransactionClient. */
	protected TransactionClient(SipProvider sip_provider) {
		super(sip_provider);
		transaction_listener = null;
	}

	/** Creates a new TransactionClient */
	public TransactionClient(SipProvider sip_provider, Message req,
			TransactionClientListener listener) {
		super(sip_provider);
		request = new Message(req);
		init(listener, request.getTransactionId());
	}

	public TransactionClient(SipProvider sip_provider, Message req,
			TransactionClientListener listener, int timeout) {
		super(sip_provider);
		request = new Message(req);
		init(listener, request.getTransactionId());
		transaction_to = new Timer(timeout, "Transaction", this);
	}

	/** Initializes timeouts and listener. */
	void init(TransactionClientListener listener,
			TransactionIdentifier transaction_id) {
		this.transaction_listener = listener;
		this.transaction_id = transaction_id;
		retransmission_to = new Timer(SipStack.retransmission_timeout,
				"Retransmission", this);
		transaction_to = new Timer(SipStack.transaction_timeout, "Transaction",
				this);
		clearing_to = new Timer(SipStack.clearing_timeout, "Clearing", this);
		printLog("id: " + String.valueOf(transaction_id), LogLevel.HIGH);
		printLog("created", LogLevel.HIGH);
	}

	/** Starts the TransactionClient and sends the transaction request. */
	public void request() {
		printLog("start", LogLevel.LOW);
		changeStatus(STATE_TRYING);
		retransmission_to.start();
		transaction_to.start();

		sip_provider.addSipProviderListener(transaction_id, this);
		connection_id = sip_provider.sendMessage(request);
	}

	/**
	 * Method derived from interface SipListener. It's fired from the
	 * SipProvider when a new message is received for to the present
	 * TransactionClient.
	 */
	public void onReceivedMessage(SipProvider provider, Message msg) {
		if (msg.isResponse()) 
		{
			int code = msg.getStatusLine().getCode();
			if (code >= 100 && code < 200
					&& (statusIs(STATE_TRYING) || statusIs(STATE_PROCEEDING))) {
				if (statusIs(STATE_TRYING))
					changeStatus(STATE_PROCEEDING);
				if (transaction_listener != null)
					transaction_listener.onTransProvisionalResponse(this, msg);
				return;
			}
			if (code >= 200 && code < 700 && (statusIs(STATE_TRYING) || statusIs(STATE_PROCEEDING))) 
			{
				retransmission_to.halt();
				transaction_to.halt();
				changeStatus(STATE_COMPLETED);
				if (code < 300) {
					if (transaction_listener != null)
						transaction_listener.onTransSuccessResponse(this, msg);
				} else {
					if (transaction_listener != null)
						transaction_listener.onTransFailureResponse(this, msg);
				}
				transaction_listener = null;
				if (true || connection_id == null) // modified
					clearing_to.start();
				else {
					printLog("clearing_to=0 for reliable transport",
							LogLevel.LOW);
					onTimeout(clearing_to);
				}
				return;
			}
		}
	}

	/**
	 * Method derived from interface TimerListener. It's fired from an active
	 * Timer.
	 */
	public void onTimeout(Timer to) {
		try {
			if (to.equals(retransmission_to)
					&& (statusIs(STATE_TRYING) || statusIs(STATE_PROCEEDING))) {
				printLog("Retransmission timeout expired", LogLevel.HIGH);
				// retransmission only for unreliable transport
				if (true || connection_id == null) { // modified
					sip_provider.sendMessage(request);
					long timeout = 2 * retransmission_to.getTime();
					if (timeout > SipStack.max_retransmission_timeout
							|| statusIs(STATE_PROCEEDING))
						timeout = SipStack.max_retransmission_timeout;
					retransmission_to = new Timer(timeout, retransmission_to
							.getLabel(), this);
					retransmission_to.start();
				} else
					printLog("No retransmissions for reliable transport ("
							+ connection_id + ")", LogLevel.LOW);
			}
			if (to.equals(transaction_to)) {
				printLog("Transaction timeout expired", LogLevel.HIGH);
				retransmission_to.halt();
				clearing_to.halt();
				sip_provider.removeSipProviderListener(transaction_id);
				changeStatus(STATE_TERMINATED);
				if (transaction_listener != null)
					transaction_listener.onTransTimeout(this);
				transaction_listener = null;
			}
			if (to.equals(clearing_to)) {
				printLog("Clearing timeout expired", LogLevel.HIGH);
				retransmission_to.halt();
				transaction_to.halt();
				sip_provider.removeSipProviderListener(transaction_id);
				changeStatus(STATE_TERMINATED);
			}
		} catch (Exception e) {
			printException(e, LogLevel.HIGH);
		}
	}

	/** Terminates the transaction. */
	public void terminate() {
		if (!statusIs(STATE_TERMINATED)) {
			retransmission_to.halt();
			transaction_to.halt();
			clearing_to.halt();
			sip_provider.removeSipProviderListener(transaction_id);
			changeStatus(STATE_TERMINATED);
			transaction_listener = null;
		}
	}

	// **************************** Logs ****************************/

	/** Adds a new string to the default Log */
	protected void printLog(String str, int level) {
		if (log != null)
			log.println("TransactionClient#" + transaction_sqn + ": " + str,
					level + SipStack.LOG_LEVEL_TRANSACTION);
	}

}
