/*
 * 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;
import org.zoolu.sip.header.ContactHeader;

/**
 * INVITE server transaction as defined in RFC 3261 (Section 17.2.1). <BR>
 * An InviteTransactionServer is responsable to create a new SIP invite
 * transaction that starts with a INVITE message received by the SipProvider and
 * ends sending a final response. <BR>
 * The changes of the internal status and the received messages are fired to the
 * TransactionListener passed to the InviteTransactionServer object. <BR>
 * This implementation of InviteTransactionServer automatically generates a "100
 * Trying" response when the INVITE message is received (as suggested by
 * RFC3261)
 */
public class InviteTransactionServer extends TransactionServer {
	/** Default behavior for automatically sending 100 Trying on INVITE. */
	public static boolean AUTO_TRYING = true;

	/**
	 * the TransactionServerListener that captures the events fired by the
	 * InviteTransactionServer
	 */
	InviteTransactionServerListener transaction_listener;

	/** last response message */
	// Message response=null;
	/** retransmission timeout ("Timer G" in RFC 3261) */
	Timer retransmission_to;
	/** end timeout ("Timer H" in RFC 3261) */
	Timer end_to;
	/** clearing timeout ("Timer I" in RFC 3261) */
	// Timer clearing_to;
	/** Whether automatically sending 100 Trying on INVITE. */
	boolean auto_trying;

	/** Creates a new InviteTransactionServer. */
	public InviteTransactionServer(SipProvider sip_provider,
			InviteTransactionServerListener listener) {
		super(sip_provider);
		init(listener, new TransactionIdentifier(SipMethods.INVITE), null);
	}

	/**
	 * Creates a new InviteTransactionServer for the already received INVITE
	 * request <i>invite</i>.
	 */
	public InviteTransactionServer(SipProvider sip_provider, Message invite,
			InviteTransactionServerListener listener) {
		super(sip_provider);
		request = new Message(invite);
		init(listener, request.getTransactionId(), request.getConnectionId());

		changeStatus(STATE_TRYING);
		sip_provider.addSipProviderListener(transaction_id, this);
		// automatically send "100 Tryng" response and go to STATE_PROCEEDING
		if (auto_trying) {
			Message trying100 = MessageFactory.createResponse(request, 100,
					SipResponses.reasonOf(100), null);
			respondWith(trying100); // this method makes it going automatically
			// to STATE_PROCEEDING
		}
	}

	/**
	 * Creates a new InviteTransactionServer for the already received INVITE
	 * request <i>invite</i>.
	 */
	public InviteTransactionServer(SipProvider sip_provider, Message invite,
			boolean auto_trying, InviteTransactionServerListener listener) {
		super(sip_provider);
		request = new Message(invite);
		init(listener, request.getTransactionId(), request.getConnectionId());
		this.auto_trying = auto_trying;

		changeStatus(STATE_TRYING);
		sip_provider.addSipProviderListener(transaction_id, this);
		// automatically send "100 Tryng" response and go to STATE_PROCEEDING
		if (auto_trying) {
			Message trying100 = MessageFactory.createResponse(request, 100,
					SipResponses.reasonOf(100), null);
			respondWith(trying100); // this method makes it going automatically
			// to STATE_PROCEEDING
		}
	}

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

	/** Whether automatically sending 100 Trying on INVITE. */
	public void setAutoTrying(boolean auto_trying) {
		this.auto_trying = auto_trying;
	}

	/** Starts the InviteTransactionServer. */
	public void listen() {
		printLog("start", LogLevel.LOW);
		if (statusIs(STATE_IDLE)) {
			changeStatus(STATE_WAITING);
			sip_provider.addSipProviderListener(new TransactionIdentifier(
					SipMethods.INVITE), this);
			sip_provider.addSipProviderListener(new TransactionIdentifier(
			        SipMethods.OPTIONS), this);

		}
	}

	/** Sends a response message */
	public void respondWith(Message resp) {
		response = resp;
		int code = response.getStatusLine().getCode();
		if (statusIs(STATE_TRYING) || statusIs(STATE_PROCEEDING))
			sip_provider.sendMessage(response, connection_id);
		if (code >= 100 && code < 200 && statusIs(STATE_TRYING)) {
			changeStatus(STATE_PROCEEDING);
			return;
		}
		if (code >= 200 && code < 300
				&& (statusIs(STATE_TRYING) || statusIs(STATE_PROCEEDING))) {
			sip_provider.removeSipProviderListener(transaction_id);
			changeStatus(STATE_TERMINATED);
			transaction_listener = null;
			return;
		}
		if (code >= 300 && code < 700
				&& (statusIs(STATE_TRYING) || statusIs(STATE_PROCEEDING))) {
			changeStatus(STATE_COMPLETED);
			// retransmission only in case of unreliable transport
			if (connection_id == null) {
				retransmission_to.start();
				end_to.start();
			} else {
				printLog("No retransmissions for reliable transport ("
						+ connection_id + ")", LogLevel.LOW);
				onTimeout(end_to);
			}
		}
	}

	/**
	 * Method derived from interface SipListener. It's fired from the
	 * SipProvider when a new message is catch for to the present
	 * ServerTransaction.
	 */
	public void onReceivedMessage(SipProvider provider, Message msg) {
		if (msg.isRequest()) {
			String req_method = msg.getRequestLine().getMethod();

			// invite received
			if (req_method.equals(SipMethods.INVITE)) {
				if (statusIs(STATE_WAITING)) {
					request = new Message(msg);
					connection_id = request.getConnectionId();
					transaction_id = request.getTransactionId();
					sip_provider.addSipProviderListener(transaction_id, this);
					sip_provider
							.removeSipProviderListener(new TransactionIdentifier(
									SipMethods.INVITE));
					changeStatus(STATE_TRYING);
					// automatically send "100 Tryng" response and go to
					// STATE_PROCEEDING
					if (auto_trying) {
						Message trying100 = MessageFactory.createResponse(
								request, 100, SipResponses.reasonOf(100), null);
						respondWith(trying100); // this method makes it going
						// automatically to
						// STATE_PROCEEDING
					}
					if (transaction_listener != null)
						transaction_listener.onTransRequest(this, msg);
					return;
				}
				if (statusIs(STATE_PROCEEDING) || statusIs(STATE_COMPLETED)) { // retransmission
					// of
					// the
					// last
					// response
					sip_provider.sendMessage(response, connection_id);
					return;
				}
			}
			
			if (req_method.equals(SipMethods.OPTIONS)) {
				Message ok200 = MessageFactory.createResponse(msg, 200, SipResponses.reasonOf(200), null);
				ok200.removeServerHeader();
				ok200.addContactHeader(new ContactHeader(ok200.getToHeader().getNameAddress()), false);
				sip_provider.sendMessage(ok200, connection_id);
				return;
			}
			
			// ack received
			if (req_method.equals(SipMethods.ACK) && statusIs(STATE_COMPLETED)) {
				retransmission_to.halt();
				end_to.halt();
				changeStatus(STATE_CONFIRMED);
				if (transaction_listener != null)
					transaction_listener.onTransFailureAck(this, msg);
				clearing_to.start();
				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_COMPLETED)) {
				printLog("Retransmission timeout expired", LogLevel.HIGH);
				long timeout = 2 * retransmission_to.getTime();
				if (timeout > SipStack.max_retransmission_timeout)
					timeout = SipStack.max_retransmission_timeout;
				retransmission_to = new Timer(timeout, retransmission_to
						.getLabel(), this);
				retransmission_to.start();
				sip_provider.sendMessage(response, connection_id);
			}
			if (to.equals(end_to) && statusIs(STATE_COMPLETED)) {
				printLog("End timeout expired", LogLevel.HIGH);
				retransmission_to.halt();
				sip_provider.removeSipProviderListener(transaction_id);
				changeStatus(STATE_TERMINATED);
				transaction_listener = null;
			}
			if (to.equals(clearing_to) && statusIs(STATE_CONFIRMED)) {
				printLog("Clearing timeout expired", LogLevel.HIGH);
				sip_provider.removeSipProviderListener(transaction_id);
				changeStatus(STATE_TERMINATED);
				transaction_listener = null;
			}
		} catch (Exception e) {
			printException(e, LogLevel.HIGH);
		}
	}

	/** Method used to drop an active transaction */
	public void terminate() {
		retransmission_to.halt();
		clearing_to.halt();
		end_to.halt();
		if (statusIs(STATE_TRYING))
			sip_provider.removeSipProviderListener(new TransactionIdentifier(
					SipMethods.INVITE));
		else
			sip_provider.removeSipProviderListener(transaction_id);
		changeStatus(STATE_TERMINATED);
		transaction_listener = null;
	}

}
