/**
     * Process a response from a distant contact.
     *
     * @param responseEvent the <tt>ResponseEvent</tt> containing the newly received SIP response.
     * @return <tt>true</tt> if the specified event has been handled by this processor and shouldn't
     *     be offered to other processors registered for the same method; <tt>false</tt>, otherwise
     */
    @Override
    public boolean processResponse(ResponseEvent responseEvent) {
      synchronized (messageProcessors) {
        for (SipMessageProcessor listener : messageProcessors)
          if (!listener.processResponse(responseEvent, sentMsg)) return true;
      }

      Request req = responseEvent.getClientTransaction().getRequest();
      int status = responseEvent.getResponse().getStatusCode();
      // content of the response
      String content = null;

      try {
        content = new String(req.getRawContent(), getCharset(req));
      } catch (UnsupportedEncodingException exc) {
        if (logger.isDebugEnabled()) logger.debug("failed to convert the message charset", exc);
        content = new String(req.getRawContent());
      }

      // to who did we send the original message ?
      ToHeader toHeader = (ToHeader) req.getHeader(ToHeader.NAME);

      if (toHeader == null) {
        // should never happen
        logger.error("send a request without a to header");
        return false;
      }

      Contact to = opSetPersPresence.resolveContactID(toHeader.getAddress().getURI().toString());

      if (to == null) {
        logger.error(
            "Error received a response from an unknown contact : "
                + toHeader.getAddress().getURI().toString()
                + " : "
                + responseEvent.getResponse().getStatusCode()
                + " "
                + responseEvent.getResponse().getReasonPhrase());

        // error for delivering the message
        fireMessageDeliveryFailed(
            // we don't know what message it concerns
            createMessage(content), to, MessageDeliveryFailedEvent.INTERNAL_ERROR);
        return false;
      }

      // we retrieve the original message
      String key = ((CallIdHeader) req.getHeader(CallIdHeader.NAME)).getCallId();

      Message newMessage = sentMsg.get(key);

      if (newMessage == null) {
        // should never happen
        logger.error("Couldn't find the message sent");

        // error for delivering the message
        fireMessageDeliveryFailed(
            // we don't know what message it is
            createMessage(content), to, MessageDeliveryFailedEvent.INTERNAL_ERROR);
        return true;
      }

      // status 401/407 = proxy authentification
      if (status >= 400 && status != 401 && status != 407) {
        if (logger.isInfoEnabled())
          logger.info(
              responseEvent.getResponse().getStatusCode()
                  + " "
                  + responseEvent.getResponse().getReasonPhrase());

        // error for delivering the message
        MessageDeliveryFailedEvent evt =
            new MessageDeliveryFailedEvent(
                newMessage,
                to,
                MessageDeliveryFailedEvent.NETWORK_FAILURE,
                System.currentTimeMillis(),
                responseEvent.getResponse().getStatusCode()
                    + " "
                    + responseEvent.getResponse().getReasonPhrase());
        fireMessageEvent(evt);
        sentMsg.remove(key);
      } else if (status == 401 || status == 407) {
        // proxy ask for authentification
        if (logger.isDebugEnabled())
          logger.debug(
              "proxy asks authentication : "
                  + responseEvent.getResponse().getStatusCode()
                  + " "
                  + responseEvent.getResponse().getReasonPhrase());

        ClientTransaction clientTransaction = responseEvent.getClientTransaction();
        SipProvider sourceProvider = (SipProvider) responseEvent.getSource();

        try {
          processAuthenticationChallenge(
              clientTransaction, responseEvent.getResponse(), sourceProvider);
        } catch (OperationFailedException ex) {
          logger.error("can't solve the challenge", ex);

          // error for delivering the message
          MessageDeliveryFailedEvent evt =
              new MessageDeliveryFailedEvent(
                  newMessage,
                  to,
                  MessageDeliveryFailedEvent.NETWORK_FAILURE,
                  System.currentTimeMillis(),
                  ex.getMessage());
          fireMessageEvent(evt);
          sentMsg.remove(key);
        }
      } else if (status >= 200) {
        if (logger.isDebugEnabled())
          logger.debug(
              "Ack received from the network : "
                  + responseEvent.getResponse().getStatusCode()
                  + " "
                  + responseEvent.getResponse().getReasonPhrase());

        // we delivered the message
        MessageDeliveredEvent msgDeliveredEvt =
            new MessageDeliveredEvent(newMessage, to, System.currentTimeMillis());

        fireMessageEvent(msgDeliveredEvt);

        // we don't need this message anymore
        sentMsg.remove(key);
      }

      return true;
    }
  /**
   * 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;
  }