/**
   * {@inheritDoc}
   *
   * <p>Implements {@link RegistrationStateChangeListener}. Notifies this instance that there has
   * been a change in the <tt>RegistrationState</tt> of {@link #protocolProvider}. Subscribes this
   * instance to {@link ColibriConferenceIQ}s as soon as <tt>protocolProvider</tt> is registered and
   * unsubscribes it as soon as <tt>protocolProvider</tt> is unregistered.
   */
  public void registrationStateChanged(RegistrationStateChangeEvent ev) {
    RegistrationState registrationState = ev.getNewState();

    if (RegistrationState.REGISTERED.equals(registrationState)) {
      protocolProvider.getConnection().addPacketListener(this, this);
    } else if (RegistrationState.UNREGISTERED.equals(registrationState)) {
      XMPPConnection connection = protocolProvider.getConnection();

      if (connection != null) connection.removePacketListener(this);
    }
  }
  /**
   * 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);
  }
  /**
   * Sends enable or disable carbon packet to the server.
   *
   * @param enable if <tt>true</tt> sends enable packet otherwise sends disable packet.
   */
  private void enableDisableCarbon(final boolean enable) {
    IQ iq =
        new IQ() {

          @Override
          public String getChildElementXML() {
            return "<" + (enable ? "enable" : "disable") + " xmlns='urn:xmpp:carbons:2' />";
          }
        };

    Packet response = null;
    try {
      PacketCollector packetCollector =
          jabberProvider
              .getConnection()
              .createPacketCollector(new PacketIDFilter(iq.getPacketID()));
      iq.setFrom(jabberProvider.getOurJID());
      iq.setType(IQ.Type.SET);
      jabberProvider.getConnection().sendPacket(iq);
      response = packetCollector.nextResult(SmackConfiguration.getPacketReplyTimeout());

      packetCollector.cancel();
    } catch (Exception e) {
      logger.error("Failed to enable carbon.", e);
    }

    isCarbonEnabled = false;

    if (response == null) {
      logger.error("Failed to enable carbon. No response is received.");
    } else if (response.getError() != null) {
      logger.error("Failed to enable carbon: " + response.getError());
    } else if (!(response instanceof IQ) || !((IQ) response).getType().equals(IQ.Type.RESULT)) {
      logger.error("Failed to enable carbon. The response is not correct.");
    } else {
      isCarbonEnabled = true;
    }
  }
  /**
   * Implements {@link PacketListener}. Notifies this instance that a specific {@link Packet} (which
   * this instance has already expressed interest into by returning <tt>true</tt> from {@link
   * #accept(Packet)}) has been received.
   *
   * @param packet the <tt>Packet</tt> which has been received and which this instance is given a
   *     chance to process
   */
  public void processPacket(Packet packet) {
    /*
     * As we do elsewhere, acknowledge the receipt of the Packet first and
     * then go about our business with it.
     */
    IQ iq = (IQ) packet;

    if (iq.getType() == IQ.Type.SET)
      protocolProvider.getConnection().sendPacket(IQ.createResultIQ(iq));

    /*
     * Now that the acknowledging is out of the way, do go about our
     * business with the Packet.
     */
    ColibriConferenceIQ conferenceIQ = (ColibriConferenceIQ) iq;
    boolean interrupted = false;

    try {
      processColibriConferenceIQ(conferenceIQ);
    } catch (Throwable t) {
      logger.error(
          "An error occurred during the processing of a " + packet.getClass().getName() + " packet",
          t);

      if (t instanceof InterruptedException) {
        /*
         * We cleared the interrupted state of the current Thread by
         * catching the InterruptedException. However, we do not really
         * care whether the current Thread has been interrupted - we
         * caught the InterruptedException because we want to swallow
         * any Throwable. Consequently, we should better restore the
         * interrupted state.
         */
        interrupted = true;
      } else if (t instanceof ThreadDeath) throw (ThreadDeath) t;
    }
    if (interrupted) Thread.currentThread().interrupt();
  }
  /**
   * Sends a file transfer request to the given <tt>toContact</tt>.
   *
   * @return the transfer object
   * @param toContact the contact that should receive the file
   * @param file file to send
   * @param gw special gateway to be used for receiver if its jid misses the domain part
   */
  FileTransfer sendFile(Contact toContact, File file, String gw)
      throws IllegalStateException, IllegalArgumentException, OperationNotSupportedException {
    OutgoingFileTransferJabberImpl outgoingTransfer = null;

    try {
      assertConnected();

      if (file.length() > getMaximumFileLength())
        throw new IllegalArgumentException("File length exceeds the allowed one for this protocol");

      String fullJid = null;
      // Find the jid of the contact which support file transfer
      // and is with highest priority if more than one found
      // if we have equals priorities
      // choose the one that is more available
      OperationSetMultiUserChat mucOpSet =
          jabberProvider.getOperationSet(OperationSetMultiUserChat.class);
      if (mucOpSet != null && mucOpSet.isPrivateMessagingContact(toContact.getAddress())) {
        fullJid = toContact.getAddress();
      } else {
        Iterator<Presence> iter =
            jabberProvider.getConnection().getRoster().getPresences(toContact.getAddress());
        int bestPriority = -1;

        PresenceStatus jabberStatus = null;

        while (iter.hasNext()) {
          Presence presence = iter.next();

          if (jabberProvider.isFeatureListSupported(
              presence.getFrom(),
              new String[] {
                "http://jabber.org/protocol/si",
                "http://jabber.org/protocol/si/profile/file-transfer"
              })) {

            int priority =
                (presence.getPriority() == Integer.MIN_VALUE) ? 0 : presence.getPriority();

            if (priority > bestPriority) {
              bestPriority = priority;
              fullJid = presence.getFrom();
              jabberStatus =
                  OperationSetPersistentPresenceJabberImpl.jabberStatusToPresenceStatus(
                      presence, jabberProvider);
            } else if (priority == bestPriority && jabberStatus != null) {
              PresenceStatus tempStatus =
                  OperationSetPersistentPresenceJabberImpl.jabberStatusToPresenceStatus(
                      presence, jabberProvider);
              if (tempStatus.compareTo(jabberStatus) > 0) {
                fullJid = presence.getFrom();
                jabberStatus = tempStatus;
              }
            }
          }
        }
      }

      // First we check if file transfer is at all supported for this
      // contact.
      if (fullJid == null) {
        throw new OperationNotSupportedException(
            "Contact client or server does not support file transfers.");
      }

      if (gw != null && !fullJid.contains("@") && !fullJid.endsWith(gw)) {
        fullJid = fullJid + "@" + gw;
      }

      OutgoingFileTransfer transfer = manager.createOutgoingFileTransfer(fullJid);

      outgoingTransfer =
          new OutgoingFileTransferJabberImpl(toContact, file, transfer, jabberProvider);

      // Notify all interested listeners that a file transfer has been
      // created.
      FileTransferCreatedEvent event = new FileTransferCreatedEvent(outgoingTransfer, new Date());

      fireFileTransferCreated(event);

      // Send the file through the Jabber file transfer.
      transfer.sendFile(file, "Sending file");

      // Start the status and progress thread.
      new FileTransferProgressThread(transfer, outgoingTransfer).start();
    } catch (XMPPException e) {
      logger.error("Failed to send file.", e);
    }

    return outgoingTransfer;
  }
  /**
   * Helper function used to send a message to a contact, with the given extensions attached.
   *
   * @param to The contact to send the message to.
   * @param toResource The resource to send the message to or null if no resource has been specified
   * @param message The message to send.
   * @param extensions The XMPP extensions that should be attached to the message before sending.
   * @return The MessageDeliveryEvent that resulted after attempting to send this message, so the
   *     calling function can modify it if needed.
   */
  private MessageDeliveredEvent sendMessage(
      Contact to, ContactResource toResource, Message message, PacketExtension[] extensions) {
    if (!(to instanceof ContactJabberImpl))
      throw new IllegalArgumentException("The specified contact is not a Jabber contact." + to);

    assertConnected();

    org.jivesoftware.smack.packet.Message msg = new org.jivesoftware.smack.packet.Message();

    String toJID = null;

    if (toResource != null) {
      if (toResource.equals(ContactResource.BASE_RESOURCE)) {
        toJID = to.getAddress();
      } else toJID = ((ContactResourceJabberImpl) toResource).getFullJid();
    }

    if (toJID == null) {
      toJID = to.getAddress();
    }

    msg.setPacketID(message.getMessageUID());
    msg.setTo(toJID);

    for (PacketExtension ext : extensions) {
      msg.addExtension(ext);
    }

    if (logger.isTraceEnabled())
      logger.trace("Will send a message to:" + toJID + " chat.jid=" + toJID);

    MessageDeliveredEvent msgDeliveryPendingEvt =
        new MessageDeliveredEvent(message, to, toResource);

    MessageDeliveredEvent[] transformedEvents =
        messageDeliveryPendingTransform(msgDeliveryPendingEvt);

    if (transformedEvents == null || transformedEvents.length == 0) return null;

    for (MessageDeliveredEvent event : transformedEvents) {
      String content = event.getSourceMessage().getContent();

      if (message.getContentType().equals(HTML_MIME_TYPE)) {
        msg.setBody(Html2Text.extractText(content));

        // Check if the other user supports XHTML messages
        // make sure we use our discovery manager as it caches calls
        if (jabberProvider.isFeatureListSupported(toJID, HTML_NAMESPACE)) {
          // Add the XHTML text to the message
          XHTMLManager.addBody(msg, OPEN_BODY_TAG + content + CLOSE_BODY_TAG);
        }
      } else {
        // this is plain text so keep it as it is.
        msg.setBody(content);
      }

      // msg.addExtension(new Version());

      if (event.isMessageEncrypted() && isCarbonEnabled) {
        msg.addExtension(new CarbonPacketExtension.PrivateExtension());
      }

      MessageEventManager.addNotificationsRequests(msg, true, false, false, true);

      String threadID = getThreadIDForAddress(toJID);
      if (threadID == null) threadID = nextThreadID();

      msg.setThread(threadID);
      msg.setType(org.jivesoftware.smack.packet.Message.Type.chat);
      msg.setFrom(jabberProvider.getConnection().getUser());

      jabberProvider.getConnection().sendPacket(msg);

      putJidForAddress(toJID, threadID);
    }

    return new MessageDeliveredEvent(message, to, toResource);
  }