/**
   * Populates a specific <tt>Request</tt> instance with the headers common to dialog-creating
   * <tt>Request</tt>s and ones sent inside existing dialogs and specific to the general event
   * package subscription functionality that this instance and a specific <tt>Subscription</tt>
   * represent.
   *
   * @param req the <tt>Request</tt> instance to be populated with common headers and ones specific
   *     to the event package of a specific <tt>Subscription</tt>
   * @param subscription the <tt>Subscription</tt> which is to be described in the specified
   *     <tt>Request</tt> i.e. its properties are to be used to populate the specified
   *     <tt>Request</tt>
   * @param expires the subscription duration to be set into the Expires header of the specified
   *     SUBSCRIBE <tt>Request</tt>
   * @throws OperationFailedException if we fail parsing or populating the subscription request.
   */
  protected void populateSubscribeRequest(Request req, Subscription subscription, int expires)
      throws OperationFailedException {
    HeaderFactory headerFactory = protocolProvider.getHeaderFactory();

    // Event
    EventHeader evHeader;
    try {
      evHeader = headerFactory.createEventHeader(eventPackage);

      String eventId = subscription.getEventId();
      if (eventId != null) evHeader.setEventId(eventId);
    } catch (ParseException e) {
      // these two should never happen.
      logger.error("An unexpected error occurred while" + "constructing the EventHeader", e);
      throw new OperationFailedException(
          "An unexpected error occurred while" + "constructing the EventHeader",
          OperationFailedException.INTERNAL_ERROR,
          e);
    }
    req.setHeader(evHeader);

    // Accept
    AcceptHeader accept;
    try {
      accept = headerFactory.createAcceptHeader("application", contentSubType);
    } catch (ParseException e) {
      logger.error("wrong accept header", e);
      throw new OperationFailedException(
          "An unexpected error occurred while" + "constructing the AcceptHeader",
          OperationFailedException.INTERNAL_ERROR,
          e);
    }
    req.setHeader(accept);

    // Expires
    ExpiresHeader expHeader;
    try {
      expHeader = headerFactory.createExpiresHeader(expires);
    } catch (InvalidArgumentException e) {
      logger.error("Invalid expires value: " + expires, e);
      throw new OperationFailedException(
          "An unexpected error occurred while" + "constructing the ExpiresHeader",
          OperationFailedException.INTERNAL_ERROR,
          e);
    }
    req.setHeader(expHeader);
  }
  /**
   * Implements {@link MethodProcessor#processResponse(ResponseEvent)}. Handles only responses to
   * SUBSCRIBE requests because they are the only requests concerning event package subscribers (and
   * the only requests sent by them, for that matter) and if the processing of a given response
   * requires event package-specific handling, delivers the response to the matching
   * <tt>Subscription</tt> instance. Examples of such event package-specific handling include
   * letting the respective <tt>Subscription</tt> handle the success or failure in the establishment
   * of a subscription.
   *
   * @param responseEvent a <tt>ResponseEvent</tt> specifying the SIP <tt>Response</tt> to be
   *     processed
   * @return <tt>true</tt> if the SIP <tt>Response</tt> specified by <tt>responseEvent</tt> was
   *     processed; otherwise, <tt>false</tt>
   */
  @Override
  public boolean processResponse(ResponseEvent responseEvent) {
    Response response = responseEvent.getResponse();

    CSeqHeader cseqHeader = (CSeqHeader) response.getHeader(CSeqHeader.NAME);
    if (cseqHeader == null) {
      logger.error("An incoming response did not contain a CSeq header");
      return false;
    }
    if (!Request.SUBSCRIBE.equals(cseqHeader.getMethod())) return false;

    ClientTransaction clientTransaction = responseEvent.getClientTransaction();
    Request request = clientTransaction.getRequest();

    /*
     * Don't handle responses to requests not coming from this event
     * package.
     */
    if (request != null) {
      EventHeader eventHeader = (EventHeader) request.getHeader(EventHeader.NAME);
      if ((eventHeader == null) || !eventPackage.equalsIgnoreCase(eventHeader.getEventType()))
        return false;
    }

    // Find the subscription.
    CallIdHeader callIdHeader = (CallIdHeader) response.getHeader(CallIdHeader.NAME);
    String callId = callIdHeader.getCallId();
    Subscription subscription = getSubscription(callId);

    // if it's the response to an unsubscribe message, we just ignore it
    // whatever the response is however if we need to handle a
    // challenge, we do it
    ExpiresHeader expHeader = response.getExpires();
    int statusCode = response.getStatusCode();
    SipProvider sourceProvider = (SipProvider) responseEvent.getSource();
    if (((expHeader != null) && (expHeader.getExpires() == 0))
        || (subscription == null)) // this handle the unsubscription
    // case where we removed the contact
    // from subscribedContacts
    {
      boolean processed = false;

      if ((statusCode == Response.UNAUTHORIZED)
          || (statusCode == Response.PROXY_AUTHENTICATION_REQUIRED)) {
        try {
          processAuthenticationChallenge(clientTransaction, response, sourceProvider);
          processed = true;
        } catch (OperationFailedException e) {
          logger.error("can't handle the challenge", e);
        }
      } else if ((statusCode != Response.OK) && (statusCode != Response.ACCEPTED)) processed = true;

      // any other cases (200/202) will imply a NOTIFY, so we will
      // handle the end of a subscription there
      return processed;
    }

    if ((statusCode >= Response.OK) && (statusCode < Response.MULTIPLE_CHOICES)) {
      // OK (200/202)
      if ((statusCode == Response.OK) || (statusCode == Response.ACCEPTED)) {
        if (expHeader == null) {
          // not conform to rfc3265
          logger.error("no Expires header in this response");
          return false;
        }

        SubscriptionRefreshTask refreshTask = new SubscriptionRefreshTask(subscription);
        subscription.setTimerTask(refreshTask);

        int refreshDelay = expHeader.getExpires();
        // try to keep a margin if the refresh delay allows it
        if (refreshDelay >= (2 * refreshMargin)) refreshDelay -= refreshMargin;
        timer.schedule(refreshTask, refreshDelay * 1000);

        // do it to remember the dialog in case of a polling
        // subscription (which means no call to finalizeSubscription)
        subscription.setDialog(clientTransaction.getDialog());

        subscription.processSuccessResponse(responseEvent, statusCode);
      }
    } else if ((statusCode >= Response.MULTIPLE_CHOICES) && (statusCode < Response.BAD_REQUEST)) {
      if (logger.isInfoEnabled())
        logger.info(
            "Response to subscribe to "
                + subscription.getAddress()
                + ": "
                + response.getReasonPhrase());
    } else if (statusCode >= Response.BAD_REQUEST) {
      // if the response is a 423 response, just re-send the request
      // with a valid expires value
      if (statusCode == Response.INTERVAL_TOO_BRIEF) {
        MinExpiresHeader min = (MinExpiresHeader) response.getHeader(MinExpiresHeader.NAME);

        if (min == null) {
          logger.error("no minimal expires value in this 423 " + "response");
          return false;
        }

        ExpiresHeader exp = request.getExpires();

        try {
          exp.setExpires(min.getExpires());
        } catch (InvalidArgumentException e) {
          logger.error("can't set the new expires value", e);
          return false;
        }

        ClientTransaction transac = null;
        try {
          transac = protocolProvider.getDefaultJainSipProvider().getNewClientTransaction(request);
        } catch (TransactionUnavailableException e) {
          logger.error("can't create the client transaction", e);
          return false;
        }

        try {
          transac.sendRequest();
        } catch (SipException e) {
          logger.error("can't send the new request", e);
          return false;
        }

        return true;
        // UNAUTHORIZED (401/407)
      } else if ((statusCode == Response.UNAUTHORIZED)
          || (statusCode == Response.PROXY_AUTHENTICATION_REQUIRED)) {
        try {
          processAuthenticationChallenge(clientTransaction, response, sourceProvider);
        } catch (OperationFailedException e) {
          logger.error("can't handle the challenge", e);

          removeSubscription(callId, subscription);
          subscription.processFailureResponse(responseEvent, statusCode);
        }
        // 408 480 486 600 603 : non definitive reject
        // others: definitive reject (or not implemented)
      } else {
        if (logger.isDebugEnabled()) logger.debug("error received from the network:\n" + response);

        removeSubscription(callId, subscription);
        subscription.processFailureResponse(responseEvent, statusCode);
      }
    }

    return true;
  }
  /**
   * Implements {@link MethodProcessor#processRequest(RequestEvent)}. Handles only NOTIFY requests
   * because they are the only requests concerning event package subscribers and if the processing
   * of a given request requires event package-specific handling, delivers the request to the
   * matching Subscription instance. Examples of such event package-specific handling include
   * handling the termination of an existing Subscription and processing the bodies of the NOTIFY
   * requests for active Subscriptions.
   *
   * @param requestEvent a <tt>RequestEvent</tt> specifying the SIP <tt>Request</tt> to be processed
   * @return <tt>true</tt> if the SIP <tt>Request</tt> specified by <tt>requestEvent</tt> was
   *     processed; otherwise, <tt>false</tt>
   */
  @Override
  public boolean processRequest(RequestEvent requestEvent) {
    Request request = requestEvent.getRequest();

    EventHeader eventHeader = (EventHeader) request.getHeader(EventHeader.NAME);
    if ((eventHeader == null) || !eventPackage.equalsIgnoreCase(eventHeader.getEventType())) {
      /*
       * We are not concerned by this request, perhaps another listener
       * is. So don't send a 489 / Bad event answer here.
       */
      return false;
    }

    if (!Request.NOTIFY.equals(request.getMethod())) return false;

    if (logger.isDebugEnabled()) logger.debug("notify received");

    SubscriptionStateHeader sstateHeader =
        (SubscriptionStateHeader) request.getHeader(SubscriptionStateHeader.NAME);
    // notify must contain one (rfc3265)
    if (sstateHeader == null) {
      logger.error("no subscription state in this request");
      return false;
    }
    String sstate = sstateHeader.getState();

    ServerTransaction serverTransaction = getOrCreateServerTransaction(requestEvent);

    // first handle the case of a contact still pending
    // it's possible if the NOTIFY arrives before the OK
    CallIdHeader callIdHeader = (CallIdHeader) request.getHeader(CallIdHeader.NAME);
    String callId = callIdHeader.getCallId();
    Subscription subscription = getSubscription(callId);

    // see if the notify correspond to an existing subscription
    if ((subscription == null) && !SubscriptionStateHeader.TERMINATED.equalsIgnoreCase(sstate)) {
      if (logger.isDebugEnabled()) logger.debug("subscription not found for callId " + callId);

      // send a 481 response (rfc3625)
      Response response;
      try {
        response =
            protocolProvider
                .getMessageFactory()
                .createResponse(Response.CALL_OR_TRANSACTION_DOES_NOT_EXIST, request);
      } catch (ParseException e) {
        logger.error("failed to create the 481 response", e);
        return false;
      }

      try {
        serverTransaction.sendResponse(response);
      } catch (SipException e) {
        logger.error("failed to send the response", e);
      } catch (InvalidArgumentException e) {
        // should not happen
        logger.error("invalid argument provided while trying to send the response", e);
      }
      return true;
    }

    // if we don't understand the content
    ContentTypeHeader ctheader = (ContentTypeHeader) request.getHeader(ContentTypeHeader.NAME);
    if ((ctheader != null) && !ctheader.getContentSubType().equalsIgnoreCase(contentSubType)) {
      // send a 415 response (rfc3261)
      Response response;
      try {
        response =
            protocolProvider
                .getMessageFactory()
                .createResponse(Response.UNSUPPORTED_MEDIA_TYPE, request);
      } catch (ParseException e) {
        logger.error("failed to create the OK response", e);
        return false;
      }

      // we want PIDF
      AcceptHeader acceptHeader;
      try {
        acceptHeader =
            protocolProvider.getHeaderFactory().createAcceptHeader("application", contentSubType);
      } catch (ParseException e) {
        // should not happen
        logger.error("failed to create the accept header", e);
        return false;
      }
      response.setHeader(acceptHeader);

      try {
        serverTransaction.sendResponse(response);
      } catch (SipException e) {
        logger.error("failed to send the response", e);
      } catch (InvalidArgumentException e) {
        // should not happen
        logger.error("invalid argument provided while trying" + " to send the response", e);
      }
    }

    // if the presentity doesn't want of us anymore
    if (SubscriptionStateHeader.TERMINATED.equalsIgnoreCase(sstate)) {
      // if we requested this end of subscription, subscription == null
      if (subscription != null) {
        removeSubscription(callId, subscription);
        subscription.processTerminatedRequest(requestEvent, sstateHeader.getReasonCode());
      }
    }

    // send an OK response
    Response response;
    try {
      response = protocolProvider.getMessageFactory().createResponse(Response.OK, request);
    } catch (ParseException e) {
      logger.error("failed to create the OK response", e);
      return false;
    }

    try {
      serverTransaction.sendResponse(response);
    } catch (SipException e) {
      logger.error("failed to send the response", e);
    } catch (InvalidArgumentException e) {
      // should not happen
      logger.error("invalid argument provided while trying to send the response", e);
    }

    // transform the presence document in new presence status
    if (subscription != null)
      subscription.processActiveRequest(requestEvent, request.getRawContent());

    return true;
  }