/*
 * Copyright (C) 2010 AVM GmbH <info@avm.de>
 * 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.dialog;

import org.zoolu.sip.address.*;
import org.zoolu.sip.transaction.*;
import org.zoolu.sip.message.*;
import org.zoolu.sip.header.*;
import org.zoolu.sip.provider.*;
import org.zoolu.tools.LogLevel;

/**
 * Class InviteDialog can be used to manage invite dialogs. An InviteDialog can
 * be both client or server. (i.e. generating an INVITE request or responding to
 * an incoming INVITE request).
 * <p>
 * An InviteDialog can be in state inviting/waiting/invited, accepted/refused,
 * call, byed/byeing, and close.
 * <p>
 * InviteDialog supports the offer/answer model for the sip body, with the
 * following rules: <br> - both INVITE-offer/2xx-answer and 2xx-offer/ACK-answer
 * modes for incoming calls <br> - INVITE-offer/2xx-answer mode for outgoing
 * calls.
 */
public class InviteDialog extends Dialog implements TransactionClientListener,
		InviteTransactionServerListener, AckTransactionServerListener,
		SipProviderListener {
	/** The last invite message */
	Message invite_req;
	
	/** fix/hack: last invite message as class variable necessary for missing ACKs 4xx responses. */
	protected static Message last_invite_req;
	
	/** The last ack message */
	Message ack_req;

	/** The InviteTransactionServer. */
	InviteTransactionServer invite_ts;
	/** The AckTransactionServer. */
	AckTransactionServer ack_ts;
	/** The BYE TransactionServer. */
	TransactionServer bye_ts;

	/** The InviteDialog listener */
	InviteDialogListener listener;

	/** Whether offer/answer are in INVITE/200_OK */
	boolean invite_offer;

	private boolean invited;
	private boolean provisional;
	private boolean cancelled_too_early;
	
	protected static final int D_INIT = 0;
	protected static final int D_WAITING = 1;
	protected static final int D_INVITING = 2;
	protected static final int D_INVITED = 3;
	protected static final int D_REFUSED = 4;
	protected static final int D_ACCEPTED = 5;
	protected static final int D_CALL = 6;

	protected static final int D_ReWAITING = 11;
	protected static final int D_ReINVITING = 12;
	protected static final int D_ReINVITED = 13;
	protected static final int D_ReREFUSED = 14;
	protected static final int D_ReACCEPTED = 15;

	protected static final int D_BYEING = 7;
	protected static final int D_BYED = 8;
	protected static final int D_CLOSE = 9;

	/** Gets the dialog state */
	protected String getStatusDescription() {
		switch (status) {
		case D_INIT:
			return "D_INIT";
		case D_WAITING:
			return "D_WAITING";
		case D_INVITING:
			return "D_INVITING";
		case D_INVITED:
			return "D_INVITED";
		case D_REFUSED:
			return "D_REFUSED";
		case D_ACCEPTED:
			return "D_ACCEPTED";
		case D_CALL:
			return "D_CALL";
		case D_ReWAITING:
			return "D_ReWAITING";
		case D_ReINVITING:
			return "D_ReINVITING";
		case D_ReINVITED:
			return "D_ReINVITED";
		case D_ReREFUSED:
			return "D_ReREFUSED";
		case D_ReACCEPTED:
			return "D_ReACCEPTED";
		case D_BYEING:
			return "D_BYEING";
		case D_BYED:
			return "D_BYED";
		case D_CLOSE:
			return "D_CLOSE";
		default:
			return null;
		}
	}
	
	protected int getStatus() 
	{
		return status;
	}

	// ************************** Public methods **************************

	/** Whether the dialog is in "early" state. */
	public boolean isEarly() {
		return status < D_ACCEPTED;
	}

	/** Whether the dialog is in "confirmed" state. */
	public boolean isConfirmed() {
		return status >= D_ACCEPTED && status < D_CLOSE;
	}

	/** Whether the dialog is in "terminated" state. */
	public boolean isTerminated() {
		return status == D_CLOSE;
	}

	/** Whether the session is "active". */
	public boolean isSessionActive() {
		return (status == D_CALL);
	}

	/** Gets the invite message */
	public Message getInviteMessage() {
		return invite_req;
	}

	/** Creates a new InviteDialog. */
	public InviteDialog(SipProvider sip_provider, InviteDialogListener listener) {
		super(sip_provider);
		init(listener);
	}

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

		changeStatus(D_INVITED);
		invite_req = invite;
		invite_ts = new InviteTransactionServer(sip_provider, invite_req, this);
		update(Dialog.UAS, invite_req);
	}

	/** Inits the InviteDialog. */
	private void init(InviteDialogListener listener) {
		log = sip_provider.getLog();
		this.listener = listener;
		this.invite_req = null;
		this.ack_req = null;
		this.invite_offer = true;
		this.invited = false;
		this.cancelled_too_early = false;
		this.provisional = false;
		changeStatus(D_INIT);
	}

	/** Starts a new InviteTransactionServer. */
	public void listen() {
		if (!statusIs(D_INIT))
			return;
		// else
		changeStatus(D_WAITING);
		invite_ts = new InviteTransactionServer(sip_provider, this);
		invite_ts.listen();
	}

	/**
	 * Starts a new InviteTransactionClient and initializes the dialog state
	 * information.
	 * 
	 * @param callee
	 *            the callee url (and display name)
	 * @param caller
	 *            the caller url (and display name)
	 * @param contact
	 *            the contact url OR the contact username
	 * @param session_descriptor
	 *            SDP body
	 */
	public void invite(String callee, String caller, String contact,
			String session_descriptor) {
		printLog("inside invite(callee,caller,contact,sdp)", LogLevel.MEDIUM);
		if (!statusIs(D_INIT))
			return;
		// else
		NameAddress to_url = new NameAddress(callee);
		NameAddress from_url = new NameAddress(caller);
		SipURL request_uri = to_url.getAddress();

		NameAddress contact_url = null;
		if (contact != null) {
			if (contact.indexOf("sip:") >= 0)
				contact_url = new NameAddress(contact);
			else
				contact_url = new NameAddress(new SipURL(contact, sip_provider
						.getViaAddress(), sip_provider.getPort()));
		} else
			contact_url = from_url;

		Message invite = MessageFactory.createInviteRequest(sip_provider,
				request_uri, to_url, from_url, contact_url, session_descriptor);
		last_invite_req = invite;
		
		// do invite
		invite(invite);
	}

	/**
	 * Starts a new InviteTransactionClient and initializes the dialog state
	 * information
	 * 
	 * @param invite
	 *            the INVITE message
	 */
	public void invite(Message invite) {
		printLog("inside invite(invite)", LogLevel.MEDIUM);
		if (!statusIs(D_INIT))
			return;
		// else
		changeStatus(D_INVITING);
		invite_req = invite;
		update(Dialog.UAC, invite_req);
		InviteTransactionClient invite_tc = new InviteTransactionClient(
				sip_provider, invite_req, this);
		provisional = false;
		invited = true;
		invite_tc.request();
	}

	/**
	 * Starts a new InviteTransactionClient with offer/answer in 2xx/ack and
	 * initializes the dialog state information
	 */
	public void inviteWithoutOffer(String callee, String caller, String contact) {
		invite_offer = false;
		invite(callee, caller, contact, null);
	}

	/**
	 * Starts a new InviteTransactionClient with offer/answer in 2xx/ack and
	 * initializes the dialog state information
	 */
	public void inviteWithoutOffer(Message invite) {
		invite_offer = false;
		invite(invite);
	}

	/**
	 * Re-invites the remote user.
	 * <p>
	 * Starts a new InviteTransactionClient and changes the dialog state
	 * information
	 * <p>
	 * Parameters: <br>- contact : the contact url OR the contact username; if
	 * null, the previous contact is used <br>- session_descriptor : the
	 * message body
	 */
	public void reInvite(String contact, String session_descriptor) {
		printLog("inside reInvite(contact,sdp)", LogLevel.MEDIUM);
		if (!statusIs(D_CALL))
			return;
		// else
		Message invite = MessageFactory.createInviteRequest(this,
				session_descriptor);
		if (contact != null) {
			NameAddress contact_url;
			if (contact.indexOf("sip:") >= 0)
				contact_url = new NameAddress(contact);
			else
				contact_url = new NameAddress(new SipURL(contact, sip_provider
						.getViaAddress(), sip_provider.getPort()));
			invite.setContactHeader(new ContactHeader(contact_url));
		}
		reInvite(invite);
	}

	/**
	 * Re-invites the remote user.
	 * <p>
	 * Starts a new InviteTransactionClient and changes the dialog state
	 * information
	 */
	public void reInvite(Message invite) {
		printLog("inside reInvite(invite)", LogLevel.MEDIUM);
		if (!statusIs(D_CALL))
			return;
		// else
		changeStatus(D_ReINVITING);
		invite_req = invite;
		update(Dialog.UAC, invite_req);
		InviteTransactionClient invite_tc = new InviteTransactionClient(
				sip_provider, invite_req, this);
		invite_tc.request();
	}

	/**
	 * Re-invites the remote user with offer/answer in 2xx/ack
	 * <p>
	 * Starts a new InviteTransactionClient and changes the dialog state
	 * information
	 */
	public void reInviteWithoutOffer(Message invite) {
		invite_offer = false;
		reInvite(invite);
	}

	/**
	 * Re-invites the remote user with offer/answer in 2xx/ack
	 * <p>
	 * Starts a new InviteTransactionClient and changes the dialog state
	 * information
	 */
	public void reInviteWithoutOffer(String contact, String session_descriptor) {
		invite_offer = false;
		reInvite(contact, session_descriptor);
	}

	/** Sends the ack when offer/answer is in 2xx/ack */
	public void ackWithAnswer(String contact, String session_descriptor) {
		if (contact != null)
			setLocalContact(new NameAddress(contact));
		Message ack = MessageFactory.create2xxAckRequest(this,
				session_descriptor);
		ackWithAnswer(ack);
	}

	/** Sends the ack when offer/answer is in 2xx/ack */
	public void ackWithAnswer(Message ack) {
		ack_req = ack;
		// reset the offer/answer flag to the default value
		invite_offer = true;
		AckTransactionClient ack_tc = new AckTransactionClient(sip_provider,
				ack, null);
		ack_tc.request();
	}

	/**
	 * Responds with <i>resp</i>. This method can be called when the
	 * InviteDialog is in D_INVITED or D_BYED states.
	 * <p>
	 * If the CSeq method is INVITE and the response is 2xx, it moves to state
	 * D_ACCEPTED, adds a new listener to the SipProviderListener, and creates
	 * new AckTransactionServer
	 * <p>
	 * If the CSeq method is INVITE and the response is not 2xx, it moves to
	 * state D_REFUSED, and sends the response.
	 */
	public void respond(Message resp)
	// private void respond(Message resp)
	{
		printLog("inside respond(resp)", LogLevel.MEDIUM);
		String method = resp.getCSeqHeader().getMethod();
		if (method.equals(SipMethods.INVITE)) {
			if (!verifyStatus(statusIs(D_INVITED) || statusIs(D_ReINVITED))) {
				printLog(
						"respond(): InviteDialog not in (re)invited state: No response now",
						LogLevel.HIGH);
				return;
			}

			int code = resp.getStatusLine().getCode();
			// 1xx provisional responses
			if (code >= 100 && code < 200) {
				invite_ts.respondWith(resp);
				return;
			}
			// For all final responses establish the dialog
			if (code >= 200) { // changeStatus(D_ACCEPTED);
				update(Dialog.UAS, resp);
			}
			// 2xx success responses
			if (code >= 200 && code < 300) {
				if (statusIs(D_INVITED))
					changeStatus(D_ACCEPTED);
				else
					changeStatus(D_ReACCEPTED);
				// terminates the INVITE Transaction server and activates an ACK
				// Transaction server
				invite_ts.terminate();
				ConnectionIdentifier conn_id = invite_ts.getConnectionId();
				ack_ts = new AckTransactionServer(sip_provider, conn_id, resp,
						this);
				ack_ts.respond();
				// if (statusIs(D_ReACCEPTED))
				// listener.onDlgReInviteAccepted(this);
				// else listener.onDlgAccepted(this);
				return;
			} else
			// 300-699 failure responses
			// if (code>=300)
			{
				if (statusIs(D_INVITED))
					changeStatus(D_REFUSED);
				else
					changeStatus(D_ReREFUSED);
				invite_ts.respondWith(resp);
				// if (statusIs(D_ReREFUSED))
				// listener.onDlgReInviteRefused(this);
				// else listener.onDlgRefused(this);
				return;
			}
		}
		if (method.equals(SipMethods.BYE)) {
			if (!verifyStatus(statusIs(D_BYED)))
				return;
			bye_ts.respondWith(resp);
		}
	}

	/**
	 * Responds with <i>code</i> and <i>reason</i>. This method can be called
	 * when the InviteDialog is in D_INVITED, D_ReINVITED states
	 */
	public void respond(int code, String reason, String contact, String sdp) {
		printLog("inside respond(" + code + "," + reason + ")", LogLevel.MEDIUM);
		if (statusIs(D_INVITED) || statusIs(D_ReINVITED)) {
			NameAddress contact_address = null;
			if (contact != null)
				contact_address = new NameAddress(contact);
			Message resp = MessageFactory.createResponse(invite_req, code,
					reason, contact_address);
			resp.setBody(sdp);
			respond(resp);
		} else
			printWarning("Dialog isn't in \"invited\" state: cannot respond ("
					+ code + "/" + getStatus() + "/" + getDialogID() + ")",
					LogLevel.MEDIUM);
	}

	/**
	 * Signals that the phone is ringing. This method should be called when the
	 * InviteDialog is in D_INVITED or D_ReINVITED state
	 */
	public void ring(String sdp) { // modified
		printLog("inside ring()", LogLevel.MEDIUM);
		respond(180, SipResponses.reasonOf(180), null, sdp);
	}

	/**
	 * Accepts the incoming call. This method should be called when the
	 * InviteDialog is in D_INVITED or D_ReINVITED state
	 */
	public void accept(String contact, String sdp) {
		printLog("inside accept(sdp)", LogLevel.MEDIUM);
		respond(200, SipResponses.reasonOf(200), contact, sdp);
	}

	/**
	 * Refuses the incoming call. This method should be called when the
	 * InviteDialog is in D_INVITED or D_ReINVITED state
	 */
	public void refuse(int code, String reason) {
		printLog("inside refuse(" + code + "," + reason + ")", LogLevel.MEDIUM);
		respond(code, reason, null, null);
	}

	/**
	 * Refuses the incoming call. This method should be called when the
	 * InviteDialog is in D_INVITED or D_ReINVITED state
	 */
	public void refuse() {
		printLog("inside refuse()", LogLevel.MEDIUM);
		// refuse(480,"Temporarily Unavailable");
		// refuse(603,"Decline");
		refuse(403, SipResponses.reasonOf(403));
	}

	public void busy() {
		refuse(486, SipResponses.reasonOf(486)); // modified		
	}
	
	/**
	 * Termiante the call. This method should be called when the InviteDialog is
	 * in D_CALL state
	 * <p>
	 * Increments the Cseq, moves to state D_BYEING, and creates new BYE
	 * TransactionClient
	 */
	public void bye() {
		printLog("inside bye()", LogLevel.MEDIUM);
		if (statusIs(D_CALL)) {
			Message bye = MessageFactory.createByeRequest(this);
			bye(bye);
		}
	}

	/**
	 * Termiante the call. This method should be called when the InviteDialog is
	 * in D_CALL state
	 * <p>
	 * Increments the Cseq, moves to state D_BYEING, and creates new BYE
	 * TransactionClient
	 */
	public void bye(Message bye) {
		printLog("inside bye(bye)", LogLevel.MEDIUM);
		if (statusIs(D_CALL)) {
			changeStatus(D_BYEING);
			// dialog_state.incLocalCSeq(); // done by
			// MessageFactory.createRequest()
			TransactionClient tc = new TransactionClient(sip_provider, bye,
					this);
			tc.request();
			// listener.onDlgByeing(this);
		}
	}

	// NB: we have to prevent cancel requests when there is no authorized invite transaction pending.
	// Instead we send cancel requests belated after receiving the provisional response.
	public boolean provisional_cancel() {
		provisional = true;
		if(cancelled_too_early) {
			cancelled_too_early = false;
			cancel();
			return true;
		}
		return false;
	}

	/**
	 * Cancel the ongoing call request or a call listening. This method should
	 * be called when the InviteDialog is in D_INVITING or D_ReINVITING state or
	 * in the D_WAITING state
	 */
	public void cancel() {
		printLog("inside cancel()", LogLevel.MEDIUM);
		if (statusIs(D_INVITING) || statusIs(D_ReINVITING)) {
			if(invited && !provisional) {
				cancelled_too_early = true;
				return;
			}
			cancelled_too_early = false;
			Message cancel = MessageFactory.createCancelRequest(last_invite_req, this); // modified // NB: invite_req
			cancel(cancel);
		} else if (statusIs(D_WAITING) || statusIs(D_ReWAITING)) {
			cancelled_too_early = false;
			if (invite_ts != null) invite_ts.terminate(); // NB: that's the reason why we send no "486 busy here" on incoming INVITE when we have an active call.
		}
	}

	/**
	 * Cancel the ongoing call request or a call listening. This method should
	 * be called when the InviteDialog is in D_INVITING or D_ReINVITING state or
	 * in the D_WAITING state
	 */
	public void cancel(Message cancel) {
		printLog("inside cancel(cancel)", LogLevel.MEDIUM);
		if (statusIs(D_INVITING) || statusIs(D_ReINVITING)) { // changeStatus(D_CANCELING);
			TransactionClient tc = new TransactionClient(sip_provider, cancel, null);
			tc.request();
		} else if (statusIs(D_WAITING) || statusIs(D_ReWAITING)) {
			invite_ts.terminate();
		}
	}

	/**
	 * Redirects the incoming call , specifing the <i>code</i> and <i>reason</i>.
	 * This method can be called when the InviteDialog is in D_INVITED or
	 * D_ReINVITED state
	 */
	public void redirect(int code, String reason, String contact) {
		printLog(
				"inside redirect(" + code + "," + reason + "," + contact + ")",
				LogLevel.MEDIUM);
		respond(code, reason, contact, null);
	}

	// ************** Inherited from SipProviderListener **************

	/**
	 * Inherited from class SipProviderListener. Called when a new message is
	 * received (out of any ongoing transaction) for the current InviteDialog.
	 * Always checks for out-of-date methods (CSeq header sequence number).
	 * <p>
	 * If the message is ACK(2xx/INVITE) request, it moves to D_CALL state, and
	 * fires <i>onDlgAck(this,body,msg)</i>.
	 * <p>
	 * If the message is 2xx(INVITE) response, it create a new
	 * AckTransactionClient
	 * <p>
	 * If the message is BYE, it moves to D_BYED state, removes the listener
	 * from SipProvider, fires onDlgBye(this,msg) then it responds with 200 OK,
	 * moves to D_CLOSE state and fires onDlgClose(this)
	 */
	public void onReceivedMessage(SipProvider sip_provider, Message msg) {
		printLog("inside onReceivedMessage(sip_provider,message)",
				LogLevel.MEDIUM);
		if (msg.isRequest() && !(msg.isAck() || msg.isCancel())
				&& msg.getCSeqHeader().getSequenceNumber() <= getRemoteCSeq()) {
			printLog(
					"Request message is too late (CSeq too small): Message discarded",
					LogLevel.HIGH);
			return;
		}
		// invite received
		if (msg.isRequest() && msg.isInvite()) {
			verifyStatus(statusIs(D_INIT) || statusIs(D_CALL));
			// NOTE: if the invite_ts.listen() is used, you should not arrive
			// here with the D_INIT state..
			// however state D_INIT has been included for robustness against
			// further changes.
			if (statusIs(D_INIT))
				changeStatus(D_INVITED);
			else
				changeStatus(D_ReINVITED);
			invite_req = msg;
			invite_ts = new InviteTransactionServer(sip_provider, invite_req,
					this);
			// ((TransactionServer)transaction).listen();
			update(Dialog.UAS, invite_req);
			if (statusIs(D_INVITED))
				listener.onDlgInvite(this, invite_req.getToHeader()
						.getNameAddress(), invite_req.getFromHeader()
						.getNameAddress(), invite_req.getBody(), invite_req);
			else
				listener.onDlgReInvite(this, invite_req.getBody(), invite_req);
		} else
		// ack (of 2xx of INVITE)
		if (msg.isRequest() && msg.isAck()) {
			if (!verifyStatus(statusIs(D_ACCEPTED) || statusIs(D_ReACCEPTED)))
				return;
			changeStatus(D_CALL);
			// terminates the AckTransactionServer
			ack_ts.terminate();
			listener.onDlgAck(this, msg.getBody(), msg);
			listener.onDlgCall(this);
		} else
		// keep sending ACK (if already sent) for any "200 OK" received
		if (msg.isResponse()) {
			if (!verifyStatus(statusIs(D_CALL)))
				return;
			int code = msg.getStatusLine().getCode();
			verifyThat(code >= 200 && code < 300, "code 2xx was expected");
			if (ack_req != null) {
				AckTransactionClient ack_tc = new AckTransactionClient(
						sip_provider, ack_req, null);
				ack_tc.request();
			}
		} else
		// bye received
		if (msg.isRequest() && msg.isBye()) {
			if (!verifyStatus(statusIs(D_CALL) || statusIs(D_BYEING)))
				return;
			changeStatus(D_BYED);
			bye_ts = new TransactionServer(sip_provider, msg, this);
			// automatically sends a 200 OK
			Message resp = MessageFactory.createResponse(msg, 200, SipResponses
					.reasonOf(200), null);
			respond(resp);
			listener.onDlgBye(this, msg);
			changeStatus(D_CLOSE);
			listener.onDlgClose(this);
		} else
		// cancel received
		if (msg.isRequest() && msg.isCancel()) {
			if (!verifyStatus(statusIs(D_INVITED) || statusIs(D_ReINVITED)))
				return;
			// create a CANCEL TransactionServer and send a 200 OK (CANCEL)
			TransactionServer ts = new TransactionServer(sip_provider, msg,
					null);
			// ts.listen();
			ts.respondWith(MessageFactory.createResponse(msg, 200, SipResponses
					.reasonOf(200), null));
			// automatically sends a 487 Cancelled
			Message resp = MessageFactory.createResponse(invite_req, 487,
					SipResponses.reasonOf(487), null);
			respond(resp);
			listener.onDlgCancel(this, msg);
		} else
		// any other request received
		if (msg.isRequest()) {
			TransactionServer ts = new TransactionServer(sip_provider, msg,
					null);
			// ts.listen();
			ts.respondWith(MessageFactory.createResponse(msg, 405, SipResponses
					.reasonOf(405), null));
		}
	}

	// ************** Inherited from InviteTransactionClientListener
	// **************

	/**
	 * Inherited from TransactionClientListener. When the
	 * TransactionClientListener is in "Proceeding" state and receives a new 1xx
	 * response
	 * <p>
	 * For INVITE transaction it fires
	 * <i>onFailureResponse(this,code,reason,body,msg)</i>.
	 */
	public void onTransProvisionalResponse(TransactionClient tc, Message msg) {
		printLog("inside onTransProvisionalResponse(tc,mdg)", LogLevel.LOW);
		if (tc.getTransactionMethod().equals(SipMethods.INVITE)) {
			StatusLine statusline = msg.getStatusLine();
			listener.onDlgInviteProvisionalResponse(this, statusline.getCode(),
					statusline.getReason(), msg.getBody(), msg);
		}
	}

	/**
	 * Inherited from TransactionClientListener. When the
	 * TransactionClientListener goes into the "Completed" state, receiving a
	 * failure response
	 * <p>
	 * If called for a INVITE transaction, it moves to D_CLOSE state, removes
	 * the listener from SipProvider.
	 * <p>
	 * If called for a BYE transaction, it moves to D_CLOSE state, removes the
	 * listener from SipProvider, and fires <i>onClose(this,msg)</i>.
	 */
	public void onTransFailureResponse(TransactionClient tc, Message msg) {
		printLog("inside onTransFailureResponse(" + tc.getTransactionId()
				+ ",msg)", LogLevel.LOW);
		if (tc.getTransactionMethod().equals(SipMethods.INVITE)) {
			if (!verifyStatus(statusIs(D_INVITING) || statusIs(D_ReINVITING)))
				return;
			StatusLine statusline = msg.getStatusLine();
			int code = statusline.getCode();
			verifyThat(code >= 300 && code < 700, "error code was expected");
			if (statusIs(D_ReINVITING)) {
				changeStatus(D_CALL);
				listener.onDlgReInviteFailureResponse(this, code, statusline
						.getReason(), msg);
			} else {
				changeStatus(D_CLOSE);
				if (code >= 300 && code < 400)
					listener.onDlgInviteRedirectResponse(this, code, statusline
							.getReason(), msg.getContacts(), msg);
				else {
					// Fix: ACK is needed after reception of 487 - this fixes endless
					// ringing on remote side after cancelling an outgoing call. NB
					this.sendAckOnTransFailureResponse(msg); 

					listener.onDlgInviteFailureResponse(this, code, statusline
							.getReason(), msg);
				}
				listener.onDlgClose(this);
			}
		} else if (tc.getTransactionMethod().equals(SipMethods.BYE)) {
			if (!verifyStatus(statusIs(D_BYEING)))
				return;
			StatusLine statusline = msg.getStatusLine();
			int code = statusline.getCode();
			verifyThat(code >= 300 && code < 700, "error code was expected");
			changeStatus(InviteDialog.D_CALL);
			listener.onDlgByeFailureResponse(this, code,
					statusline.getReason(), msg);
		}
	}

	/**
	 * Inherited from TransactionClientListener. When an
	 * TransactionClientListener goes into the "Terminated" state, receiving a
	 * 2xx response
	 * <p>
	 * If called for a INVITE transaction, it updates the dialog information,
	 * moves to D_CALL state, add a listener to the SipProvider, creates a new
	 * AckTransactionClient(ack,this), and fires
	 * <i>onSuccessResponse(this,code,body,msg)</i>.
	 * <p>
	 * If called for a BYE transaction, it moves to D_CLOSE state, removes the
	 * listener from SipProvider, and fires <i>onClose(this,msg)</i>.
	 */
	public void onTransSuccessResponse(TransactionClient tc, Message msg) {
		printLog("inside onTransSuccessResponse(tc,msg)", LogLevel.LOW);
		if (tc.getTransactionMethod().equals(SipMethods.INVITE)) {
			if (!verifyStatus(statusIs(D_INVITING) || statusIs(D_ReINVITING)))
				return;
			StatusLine statusline = msg.getStatusLine();
			int code = statusline.getCode();
			if (!verifyThat(code >= 200 && code < 300
					&& msg.getTransactionMethod().equals(SipMethods.INVITE),
					"2xx for invite was expected"))
				return;
			boolean re_inviting = statusIs(D_ReINVITING);
			changeStatus(D_CALL);
			update(Dialog.UAC, msg);
			if (invite_offer) { // invite_req=MessageFactory.createRequest(SipMethods.ACK,dialog_state,sdp.toString());
				// ack=MessageFactory.createRequest(this,SipMethods.ACK,null);
				ack_req = MessageFactory.create2xxAckRequest(this, null);
				AckTransactionClient ack_tc = new AckTransactionClient(
						sip_provider, ack_req, null);
				ack_tc.request();
			}
			if (!re_inviting) {
				listener.onDlgInviteSuccessResponse(this, code, statusline
						.getReason(), msg.getBody(), msg);
				listener.onDlgCall(this);
			} else
				listener.onDlgReInviteSuccessResponse(this, code, statusline
						.getReason(), msg.getBody(), msg);
		} else if (tc.getTransactionMethod().equals(SipMethods.BYE)) {
			if (!verifyStatus(statusIs(D_BYEING)))
				return;
			StatusLine statusline = msg.getStatusLine();
			int code = statusline.getCode();
			verifyThat(code >= 200 && code < 300, "2xx for bye was expected");
			changeStatus(D_CLOSE);
			listener.onDlgByeSuccessResponse(this, code,
					statusline.getReason(), msg);
			listener.onDlgClose(this);
		}
	}

	/**
	 * Inherited from TransactionClientListener. When the TransactionClient goes
	 * into the "Terminated" state, caused by transaction timeout
	 */
	public void onTransTimeout(TransactionClient tc) {
		printLog("inside onTransTimeout(tc,msg)", LogLevel.LOW);
		if (tc.getTransactionMethod().equals(SipMethods.INVITE)) {
			if (!verifyStatus(statusIs(D_INVITING) || statusIs(D_ReINVITING)))
				return;
			changeStatus(D_CLOSE);
			listener.onDlgTimeout(this);
			listener.onDlgClose(this);
		} else if (tc.getTransactionMethod().equals(SipMethods.BYE)) {
			if (!verifyStatus(statusIs(D_BYEING)))
				return;
			changeStatus(D_CLOSE);
			listener.onDlgClose(this);
		}
	}

	// ************** Inherited from InviteTransactionServerListener
	// **************

	/** Fix for missing ACK after 4xx responses in INVITE transaction. */
	private void sendAckOnTransFailureResponse(Message resp) {
		if(last_invite_req != null) {
			Message ack = MessageFactory.createNon2xxAckRequest(sip_provider, last_invite_req, resp);
			sip_provider.sendMessage(ack);
		}
	}		

	/**
	 * Inherited from TransactionServerListener. When the TransactionServer goes
	 * into the "Trying" state receiving a request
	 * <p>
	 * If called for a INVITE transaction, it initializes the dialog
	 * information, <br>
	 * moves to D_INVITED state, and add a listener to the SipProvider, <br>
	 * and fires <i>onInvite(caller,body,msg)</i>.
	 */
	public void onTransRequest(TransactionServer ts, Message req) {
		printLog("inside onTransRequest(ts,msg)", LogLevel.LOW);
		if (ts.getTransactionMethod().equals(SipMethods.INVITE)) {
			if (!verifyStatus(statusIs(D_WAITING)))
				return;
			changeStatus(D_INVITED);
			invite_req = req;
			update(Dialog.UAS, invite_req);
			listener.onDlgInvite(this, invite_req.getToHeader()
					.getNameAddress(), invite_req.getFromHeader()
					.getNameAddress(), invite_req.getBody(), invite_req);
		}
	}

	/**
	 * Inherited from InviteTransactionServerListener. When an
	 * InviteTransactionServer goes into the "Confirmed" state receining an ACK
	 * for NON-2xx response
	 * <p>
	 * It moves to D_CLOSE state and removes the listener from SipProvider.
	 */
	public void onTransFailureAck(InviteTransactionServer ts, Message msg) {
		printLog("inside onTransFailureAck(ts,msg)", LogLevel.LOW);
		if (!verifyStatus(statusIs(D_REFUSED) || statusIs(D_ReREFUSED)))
			return;
		if (statusIs(D_ReREFUSED)) {
			changeStatus(D_CALL);
		} else {
			changeStatus(D_CLOSE);
			listener.onDlgClose(this);
		}
	}

	// ************ Inherited from AckTransactionServerListener ************

	/**
	 * When the AckTransactionServer goes into the "Terminated" state, caused by
	 * transaction timeout
	 */
	public void onTransAckTimeout(AckTransactionServer ts) {
		printLog("inside onAckSrvTimeout(ts)", LogLevel.LOW);
		if (!verifyStatus(statusIs(D_ACCEPTED) || statusIs(D_ReACCEPTED)
				|| statusIs(D_REFUSED) || statusIs(D_ReREFUSED)))
			return;
		printLog("No ACK received..", LogLevel.HIGH);
		changeStatus(D_CLOSE);
		listener.onDlgClose(this);
	}
	
	// **************************** Logs ****************************/

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

}
