/**
   * Updates an <tt>Endpoint</tt> of this <tt>Conference</tt> with the information contained in
   * <tt>colibriEndpoint</tt>. The ID of <tt>colibriEndpoint</tt> is used to select the
   * <tt>Endpoint</tt> to update.
   *
   * @param colibriEndpoint a <tt>ColibriConferenceIQ.Endpoint</tt> instance that contains
   *     information to be set on an <tt>Endpoint</tt> instance of this <tt>Conference</tt>.
   */
  void updateEndpoint(ColibriConferenceIQ.Endpoint colibriEndpoint) {
    String id = colibriEndpoint.getId();

    if (id != null) {
      Endpoint endpoint = getEndpoint(id);

      if (endpoint != null) {
        String oldDisplayName = endpoint.getDisplayName();
        String newDisplayName = colibriEndpoint.getDisplayName();

        if ((oldDisplayName == null && newDisplayName != null)
            || (oldDisplayName != null && !oldDisplayName.equals(newDisplayName))) {
          endpoint.setDisplayName(newDisplayName);

          if (isRecording() && endpointRecorder != null) endpointRecorder.updateEndpoint(endpoint);

          EventAdmin eventAdmin = getVideobridge().getEventAdmin();
          if (eventAdmin != null) {
            eventAdmin.sendEvent(EventFactory.endpointDisplayNameChanged(endpoint));
          }
        }
      }
    }
  }
  /**
   * Handles presence stanzas
   *
   * @param presence
   */
  private void handlePresence(Presence presence) {
    // unavailable is sent when user leaves the room
    if (!presence.isAvailable()) {
      return;
    }

    String from = presence.getFrom();
    JitsiMeetConference conference = getConferenceForMucJid(from);

    if (conference == null) {
      if (logger.isDebugEnabled()) {
        logger.debug("Room not found for JID: " + from);
      }
      return;
    }

    ChatRoomMemberRole role = conference.getRoleForMucJid(from);

    if (role != null && role.compareTo(ChatRoomMemberRole.MODERATOR) < 0) {
      StartMutedPacketExtension ext =
          (StartMutedPacketExtension)
              presence.getExtension(
                  StartMutedPacketExtension.ELEMENT_NAME, StartMutedPacketExtension.NAMESPACE);

      if (ext != null) {
        boolean[] startMuted = {ext.getAudioMuted(), ext.getVideoMuted()};

        conference.setStartMuted(startMuted);
      }
    }

    Participant participant = conference.findParticipantForRoomJid(from);
    ColibriConference colibriConference = conference.getColibriConference();

    if (participant != null && colibriConference != null) {
      // Check if this conference is valid
      String conferenceId = colibriConference.getConferenceId();
      if (StringUtils.isNullOrEmpty(conferenceId)) {
        logger.error("Unable to send DisplayNameChanged event" + " - no conference id");
        return;
      }

      // Check for changes to the display name
      String oldDisplayName = participant.getDisplayName();
      String newDisplayName = null;
      for (PacketExtension pe : presence.getExtensions()) {
        if (pe instanceof Nick) {
          newDisplayName = ((Nick) pe).getName();
          break;
        }
      }

      if (!Objects.equals(oldDisplayName, newDisplayName)) {
        participant.setDisplayName(newDisplayName);

        EventAdmin eventAdmin = FocusBundleActivator.getEventAdmin();
        if (eventAdmin != null) {
          // Prevent NPE when adding to event hashtable
          if (newDisplayName == null) {
            newDisplayName = "";
          }
          eventAdmin.sendEvent(
              EventFactory.endpointDisplayNameChanged(
                  conferenceId, participant.getEndpointId(), newDisplayName));
        }
      }
    }
  }