Receiving the rating of a pharmacy against an order with feedback (Java)

In this use case, the user rates the pharmacy that created the order. The rating is usually between 1 to 5. The pharmacy sometimes asks for a reason why the user has provided a particular rating.

Code snippets

BPP receives protocol rating

/*
Example Request JSON:
{
    "context": {
        "domain": "nic2004:52311",
        "country": "IND",
        "city": "std:080",
        "action": "rating",
        "core_version": "0.9.2",
        "bap_id": "https://mock_bap.com/",
        "bap_uri": "https://mock_bap.com/beckn/",
        "transaction_id": "1239890342",
        "message_id": "123793824",
        "timestamp": "2021-03-23T10:00:40.065Z"
    },
    "message": {
        "id": "order_1",
        "value": 5
    }
}
*/
    // BPP Rating Endpoint
    @PostMapping("/bpp/rating")
    public ResponseEntity rating(
            @RequestHeader HttpHeaders headers,
            @RequestBody RatingRequest request) {
        var response = bppApplicationService.rating(request, headers);
        return ResponseEntity.ok(response);
    }

BPP processes the rating

    public Response rating(RatingRequest request, HttpHeaders headers) {
        var onRatingRequest = new OnRatingRequest();
        // Validate the headers
        var isHeadersValid = validateHeaders(headers);
        // Construct and return error
        if (!isHeadersValid) return null;

        // Rate the given order
        var rateOrder = request.getMessage().getId();

        // Execute business logic here

        // Generate the response
        onRatingRequest = rateStore(rateOrder);

        //invoke on_rate api
        return invokeOnRating(onRatingRequest, headers);
    }
}

BPP generates response

/*
Example Response JSON:
{
    "context": {
        "domain": "nic2004:52311",
        "country": "IND",
        "city": "std:080",
        "action": "on_rating",
        "core_version": "0.9.2",
        "bap_id": "https://mock_bap.com/",
        "bap_uri": "https://mock_bap.com/beckn/",
        "transaction_id": "1239890342",
        "message_id": "123793824",
        "timestamp": "2021-03-23T10:00:40.065Z"
    },
    "message": {
        "feedback": {
            "id": "rating_1",
            "descriptor": "https://feedback.bpp.com/provider/good-health-pharma/2839",
            "parent_id": "order_1"
        }
    }
}
*/
    public OnRatingRequest rateStore(OrderRating orderRating) {
        var ratingResult = RatingResponseBuilder.builder.result(orderRating).build();
        // Convert response into protocol object similar to example above
        return ratingResult;
    }

BPP calls protocol on_rating

    public Response invokeOnRating(OnRatingRequest ratingResponse, HttpHeaders headers) {
        if(ratingResponse.getError() == null) {
            // Call BAP on_rating api with the order response

            // Call to look up function which returns the the public key and BAP Endpoint to be called 
            var url = lookUp(headers);

            // Call BAP on_rating api with the rating order object
            var response = apiClient.post(url[0] + Context.ActionEnum.on_rating,
                constructResponseHeaders(),
                ratingResponse,
                OnRatingRequest.class);
            return Response.of("ACK", null);
        } else {
            return Response.of("NACK", null);
        }
    }