public ResponseEntity receiveMessage()

in sessions/next24/books-genai-vertex-langchain4j/src/main/java/services/web/ImageProcessingController.java [105:147]
27 lines of code
3 McCabe index (conditional complexity)

    public ResponseEntity<String> receiveMessage(
            @RequestBody Map<String, Object> body, @RequestHeader Map<String, String> headers) throws IOException, InterruptedException, ExecutionException {
        String errorMsg = RequestValidationUtility.validateRequest(body,headers);
        if (!errorMsg.isBlank()) {
            return new ResponseEntity<>(errorMsg, HttpStatus.BAD_REQUEST);
        }

        String fileName = (String)body.get("name");
        String bucketName = (String)body.get("bucket");

        logger.info("New picture uploaded " + fileName);

        // multi-modal call to retrieve text from the uploaded image
        String response = vertexAIClient.promptOnImage(promptImage, bucketName, fileName);

        // parse the response and extract the data
        Map<String, Object> jsonMap = JsonUtility.parseJsonToMap(response);

        // get book details
        String title = (String) jsonMap.get("title");
        String author = (String) jsonMap.get("author");
        logger.info(String.format("Result: Author %s, Title %s", author, title));

        // retrieve the book summary from the database
        String summary = booksService.getBookSummary(title);
        logger.info("The summary of the book:"+ title+ " is: " + summary);

        // Function calling BookStoreService
        UserMessage userMessage = new UserMessage(
                String.format("Write a nice note including book author, book title and availability. Find out if the book with the title %s by author %s is available in the University bookstore.Please add also this book summary to the response, with the text available after the column, prefix it with My Book Summary:  %s",
                        title, author, summary));

        String bookStoreResponse = vertexAIClient.promptModelwithFunctionCalls(userMessage,
                new BookStoreService());

        // Saving result to Firestore
        if (bookStoreResponse != null) {
            ApiFuture<WriteResult> writeResult = eventService.storeBookInfo(fileName, title, author, summary, bookStoreResponse);
            logger.info("Picture metadata saved in Firestore at " + writeResult.get().getUpdateTime());
        }

        return new ResponseEntity<String>(HttpStatus.OK);
    }