/**
  * Utility method throwing an exception if the stack is not properly initialized.
  *
  * @throws java.lang.IllegalStateException if the underlying stack is not registered and
  *     initialized.
  */
 private void assertConnected() throws IllegalStateException {
   if (icqProvider == null)
     throw new IllegalStateException(
         "The provider must be non-null and signed on the "
             + "service before being able to send a file.");
   else if (!icqProvider.isRegistered())
     throw new IllegalStateException(
         "The provider must be signed on the service before " + "being able to send a file.");
 }
  /**
   * Sends a file transfer request to the given <tt>toContact</tt> by specifying the local and
   * remote file path and the <tt>fromContact</tt>, sending the file.
   *
   * @param toContact the contact that should receive the file
   * @param file the file to send
   * @return the transfer object
   * @throws IllegalStateException if the protocol provider is not registered or connected
   * @throws IllegalArgumentException if some of the arguments doesn't fit the protocol requirements
   */
  public FileTransfer sendFile(Contact toContact, File file)
      throws IllegalStateException, IllegalArgumentException {
    assertConnected();

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

    // Get the aim connection
    AimConnection aimConnection = icqProvider.getAimConnection();

    // Create an outgoing file transfer instance
    OutgoingFileTransfer outgoingFileTransfer =
        aimConnection
            .getIcbmService()
            .getRvConnectionManager()
            .createOutgoingFileTransfer(new Screenname(toContact.getAddress()));

    String id =
        String.valueOf(outgoingFileTransfer.getRvSessionInfo().getRvSession().getRvSessionId());

    FileTransferImpl outFileTransfer =
        new FileTransferImpl(outgoingFileTransfer, id, toContact, file, FileTransfer.OUT);

    // Adding the file to the outgoing file transfer
    try {
      outgoingFileTransfer.setSingleFile(new File(file.getPath()));
    } catch (IOException e) {
      if (logger.isDebugEnabled()) logger.debug("Error sending file", e);
      return null;
    }

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

    fireFileTransferCreated(event);

    // Sending the file
    outgoingFileTransfer.sendRequest(new InvitationMessage(""));

    outFileTransfer.fireStatusChangeEvent(FileTransferStatusChangeEvent.PREPARING);

    return outFileTransfer;
  }
  /**
   * Function called when a icq file transfer request arrive
   *
   * @param manager the joustsim manager
   * @param transfer the incoming transfer
   */
  public void handleNewIncomingConnection(
      RvConnectionManager manager, IncomingRvConnection transfer) {
    if (transfer instanceof IncomingFileTransfer) {
      if (logger.isTraceEnabled())
        logger.trace("Incoming Icq file transfer request " + transfer.getClass());

      if (!(transfer instanceof IncomingFileTransfer)) {
        logger.warn("Wrong file transfer.");
        return;
      }

      OperationSetPersistentPresenceIcqImpl opSetPersPresence =
          (OperationSetPersistentPresenceIcqImpl)
              icqProvider.getOperationSet(OperationSetPersistentPresence.class);

      Contact sender =
          opSetPersPresence.findContactByID(transfer.getBuddyScreenname().getFormatted());

      IncomingFileTransfer incomingFileTransfer = (IncomingFileTransfer) transfer;

      final Date newDate = new Date();
      final IncomingFileTransferRequest req =
          new IncomingFileTransferRequestIcqImpl(
              icqProvider, this, incomingFileTransfer, sender, newDate);

      // this handels when we receive request and before accept or decline
      // it we receive cancel
      transfer.addEventListener(
          new RvConnectionEventListener() {
            public void handleEventWithStateChange(
                RvConnection transfer, RvConnectionState state, RvConnectionEvent event) {
              if (state == FileTransferState.FAILED && event instanceof BuddyCancelledEvent) {
                fireFileTransferRequestCanceled(
                    new FileTransferRequestEvent(
                        OperationSetFileTransferIcqImpl.this, req, newDate));
              }
            }

            public void handleEvent(RvConnection arg0, RvConnectionEvent arg1) {}
          });

      fireFileTransferRequest(new FileTransferRequestEvent(this, req, newDate));
    }
  }
  /**
   * Create a new FileTransfer OperationSet over the specified Icq provider
   *
   * @param icqProvider ICQ protocol provider service
   */
  public OperationSetFileTransferIcqImpl(ProtocolProviderServiceIcqImpl icqProvider) {
    this.icqProvider = icqProvider;

    icqProvider.addRegistrationStateChangeListener(new RegistrationStateListener());
  }