/**
   * Insert paragraph REST API
   *
   * @param message - JSON containing paragraph's information
   * @return JSON with status.OK
   * @throws IOException
   */
  @POST
  @Path("{notebookId}/paragraph")
  @ZeppelinApi
  public Response insertParagraph(@PathParam("notebookId") String notebookId, String message)
      throws IOException {
    LOG.info("insert paragraph {} {}", notebookId, message);

    Note note = notebook.getNote(notebookId);
    if (note == null) {
      return new JsonResponse(Status.NOT_FOUND, "note not found.").build();
    }

    NewParagraphRequest request = gson.fromJson(message, NewParagraphRequest.class);

    Paragraph p;
    Double indexDouble = request.getIndex();
    if (indexDouble == null) {
      p = note.addParagraph();
    } else {
      p = note.insertParagraph(indexDouble.intValue());
    }
    p.setTitle(request.getTitle());
    p.setText(request.getText());

    AuthenticationInfo subject = new AuthenticationInfo(SecurityUtils.getPrincipal());
    note.persist(subject);
    notebookServer.broadcastNote(note);
    return new JsonResponse(Status.CREATED, "", p.getId()).build();
  }
  /**
   * Create new note REST API
   *
   * @param message - JSON with new note name
   * @return JSON with new note ID
   * @throws IOException
   */
  @POST
  @Path("/")
  @ZeppelinApi
  public Response createNote(String message) throws IOException {
    LOG.info("Create new notebook by JSON {}", message);
    NewNotebookRequest request = gson.fromJson(message, NewNotebookRequest.class);
    AuthenticationInfo subject = new AuthenticationInfo(SecurityUtils.getPrincipal());
    Note note = notebook.createNote(subject);
    List<NewParagraphRequest> initialParagraphs = request.getParagraphs();
    if (initialParagraphs != null) {
      for (NewParagraphRequest paragraphRequest : initialParagraphs) {
        Paragraph p = note.addParagraph();
        p.setTitle(paragraphRequest.getTitle());
        p.setText(paragraphRequest.getText());
      }
    }
    note.addParagraph(); // add one paragraph to the last
    String noteName = request.getName();
    if (noteName.isEmpty()) {
      noteName = "Note " + note.getId();
    }

    note.setName(noteName);
    note.persist(subject);
    notebookServer.broadcastNote(note);
    notebookServer.broadcastNoteList(subject);
    return new JsonResponse<>(Status.CREATED, "", note.getId()).build();
  }