protected RestChannelConsumer prepareRequest()

in src/main/java/org/opensearch/performanceanalyzer/http_action/config/PerformanceAnalyzerResourceProvider.java [158:217]
53 lines of code
8 McCabe index (conditional complexity)

    protected RestChannelConsumer prepareRequest(RestRequest request, NodeClient client)
            throws IOException {
        StringBuilder response = new StringBuilder();
        String inputLine;
        int responseCode;

        URL url = getAgentUri(request);
        // 'url' is null if no correct mapping for input uri is found
        if (url == null) {
            return channel -> {
                RestResponse finalResponse = new BytesRestResponse(RestStatus.NOT_FOUND, "");
                channel.sendResponse(finalResponse);
            };
        } else {
            HttpURLConnection httpURLConnection =
                    isHttpsEnabled ? createHttpsURLConnection(url) : createHttpURLConnection(url);
            // Build Response in buffer
            responseCode = httpURLConnection.getResponseCode();
            InputStream inputStream =
                    (responseCode == HttpsURLConnection.HTTP_OK)
                            ? httpURLConnection.getInputStream()
                            : httpURLConnection.getErrorStream();

            try (BufferedReader in = new BufferedReader(new InputStreamReader(inputStream))) {
                while ((inputLine = in.readLine()) != null) {
                    response.append(inputLine);
                }
                LOG.debug("Response received - {}", response);
            } catch (Exception ex) {
                LOG.error("Error receiving response for Request Uri {} - {}", request.uri(), ex);
                return channel -> {
                    channel.sendResponse(
                            new BytesRestResponse(
                                    RestStatus.INTERNAL_SERVER_ERROR,
                                    "Encountered error possibly with downstream APIs"));
                };
            }

            RestResponse finalResponse =
                    new BytesRestResponse(
                            RestStatus.fromCode(responseCode), String.valueOf(response));
            LOG.debug("finalResponse: {}", finalResponse);

            return channel -> {
                try {
                    Map<String, List<String>> map = httpURLConnection.getHeaderFields();
                    for (Map.Entry<String, List<String>> entry : map.entrySet()) {
                        finalResponse.addHeader(entry.getKey(), entry.getValue().toString());
                    }
                    // Send Response back to callee
                    channel.sendResponse(finalResponse);
                } catch (Exception ex) {
                    LOG.error("Error sending response", ex);
                    channel.sendResponse(
                            new BytesRestResponse(
                                    RestStatus.INTERNAL_SERVER_ERROR, "Something went wrong"));
                }
            };
        }
    }