/**
   * Subscribes this provider as interested in receiving notifications for new mail messages from
   * Google mail services such as Gmail or Google Apps.
   */
  private void subscribeForGmailNotifications() {
    // first check support for the notification service
    String accountIDService = jabberProvider.getAccountID().getService();
    boolean notificationsAreSupported =
        jabberProvider.isFeatureSupported(accountIDService, NewMailNotificationIQ.NAMESPACE);

    if (!notificationsAreSupported) {
      if (logger.isDebugEnabled())
        logger.debug(
            accountIDService
                + " does not seem to provide a Gmail notification "
                + " service so we won't be trying to subscribe for it");
      return;
    }

    if (logger.isDebugEnabled())
      logger.debug(
          accountIDService
              + " seems to provide a Gmail notification "
              + " service so we will try to subscribe for it");

    ProviderManager providerManager = ProviderManager.getInstance();

    providerManager.addIQProvider(
        MailboxIQ.ELEMENT_NAME, MailboxIQ.NAMESPACE, new MailboxIQProvider());
    providerManager.addIQProvider(
        NewMailNotificationIQ.ELEMENT_NAME,
        NewMailNotificationIQ.NAMESPACE,
        new NewMailNotificationProvider());

    Connection connection = jabberProvider.getConnection();

    connection.addPacketListener(new MailboxIQListener(), new PacketTypeFilter(MailboxIQ.class));
    connection.addPacketListener(
        new NewMailNotificationListener(), new PacketTypeFilter(NewMailNotificationIQ.class));

    if (opSetPersPresence.getCurrentStatusMessage().equals(JabberStatusEnum.OFFLINE)) return;

    // create a query with -1 values for newer-than-tid and
    // newer-than-time attributes
    MailboxQueryIQ mailboxQuery = new MailboxQueryIQ();

    if (logger.isTraceEnabled())
      logger.trace(
          "sending mailNotification for acc: "
              + jabberProvider.getAccountID().getAccountUniqueID());
    jabberProvider.getConnection().sendPacket(mailboxQuery);
  }
 /**
  * Checks whether the carbon is supported by the server or not.
  *
  * @return <tt>true</tt> if carbon is supported by the server and <tt>false</tt> if not.
  */
 private boolean isCarbonSupported() {
   try {
     return jabberProvider
         .getDiscoveryManager()
         .discoverInfo(jabberProvider.getAccountID().getService())
         .containsFeature(CarbonPacketExtension.NAMESPACE);
   } catch (XMPPException e) {
     logger.warn("Failed to retrieve carbon support." + e.getMessage());
   }
   return false;
 }
  /** Initialize additional services, like gmail notifications and message carbons. */
  private void initAdditionalServices() {
    // subscribe for Google (Gmail or Google Apps) notifications
    // for new mail messages.
    boolean enableGmailNotifications =
        jabberProvider
            .getAccountID()
            .getAccountPropertyBoolean("GMAIL_NOTIFICATIONS_ENABLED", false);

    if (enableGmailNotifications) subscribeForGmailNotifications();

    boolean enableCarbon =
        isCarbonSupported()
            && !jabberProvider
                .getAccountID()
                .getAccountPropertyBoolean(ProtocolProviderFactory.IS_CARBON_DISABLED, false);
    if (enableCarbon) {
      enableDisableCarbon(true);
    } else {
      isCarbonEnabled = false;
    }
  }
  /**
   * Creates an html description of the specified mailbox.
   *
   * @param mailboxIQ the mailboxIQ that we are to describe.
   * @return an html description of <tt>mailboxIQ</tt>
   */
  private String createMailboxDescription(MailboxIQ mailboxIQ) {
    int threadCount = mailboxIQ.getThreadCount();

    String resourceHeaderKey =
        threadCount > 1 ? "service.gui.NEW_GMAIL_MANY_HEADER" : "service.gui.NEW_GMAIL_HEADER";

    String resourceFooterKey =
        threadCount > 1 ? "service.gui.NEW_GMAIL_MANY_FOOTER" : "service.gui.NEW_GMAIL_FOOTER";

    // FIXME Escape HTML!
    String newMailHeader =
        JabberActivator.getResources()
            .getI18NString(
                resourceHeaderKey,
                new String[] {
                  jabberProvider.getAccountID().getService(), // {0} - service name
                  mailboxIQ.getUrl(), // {1} - inbox URI
                  Integer.toString(threadCount) // {2} - thread count
                });

    StringBuilder message = new StringBuilder(newMailHeader);

    // we now start an html table for the threads.
    message.append("<table width=100% cellpadding=2 cellspacing=0 ");
    message.append("border=0 bgcolor=#e8eef7>");

    Iterator<MailThreadInfo> threads = mailboxIQ.threads();

    String maxThreadsStr =
        (String)
            JabberActivator.getConfigurationService()
                .getProperty(PNAME_MAX_GMAIL_THREADS_PER_NOTIFICATION);

    int maxThreads = 5;

    try {
      if (maxThreadsStr != null) maxThreads = Integer.parseInt(maxThreadsStr);
    } catch (NumberFormatException e) {
      if (logger.isDebugEnabled())
        logger.debug("Failed to parse max threads count: " + maxThreads + ". Going for default.");
    }

    // print a maximum of MAX_THREADS
    for (int i = 0; i < maxThreads && threads.hasNext(); i++) {
      message.append(threads.next().createHtmlDescription());
    }
    message.append("</table><br/>");

    if (threadCount > maxThreads) {
      String messageFooter =
          JabberActivator.getResources()
              .getI18NString(
                  resourceFooterKey,
                  new String[] {
                    mailboxIQ.getUrl(), // {0} - inbox URI
                    Integer.toString(threadCount - maxThreads) // {1} - thread count
                  });
      message.append(messageFooter);
    }

    return message.toString();
  }