From 7e0752956b65ac9828f910f4613b1cd039094ec1 Mon Sep 17 00:00:00 2001
From: Nipuna Marcus <nipunac@wso2.com>
Date: Sat, 16 Nov 2019 13:19:13 +0530
Subject: [PATCH] Add requested changes

---
 .../RecommendationService_sample_service.bal  | 57 ++++++++++---------
 1 file changed, 30 insertions(+), 27 deletions(-)

diff --git a/src/recommendationservice_ballerina/src/recommendationservice/RecommendationService_sample_service.bal b/src/recommendationservice_ballerina/src/recommendationservice/RecommendationService_sample_service.bal
index a24d422..f206de9 100644
--- a/src/recommendationservice_ballerina/src/recommendationservice/RecommendationService_sample_service.bal
+++ b/src/recommendationservice_ballerina/src/recommendationservice/RecommendationService_sample_service.bal
@@ -1,9 +1,10 @@
 import ballerina/grpc;
-import ballerina/io;
+import ballerina/log;
 import ballerina/kubernetes;
 
 // Product catalog client.
-ProductCatalogServiceBlockingClient productCat = new ("http://productcatalogservice:3550");
+ProductCatalogServiceBlockingClient catalogClient = new ("http://productcatalogservice:3550");
+final Empty req = {};
 
 @kubernetes:Service {
     serviceType: "ClusterIP",
@@ -12,59 +13,61 @@ ProductCatalogServiceBlockingClient productCat = new ("http://productcatalogserv
 service RecommendationService on new grpc:Listener(8080) {
 
     resource function ListRecommendations(grpc:Caller caller, ListRecommendationsRequest value) {
-        Empty req = {};
         // Fetch list of products from product catalog stub
-        var products = productCat->ListProducts(req);
+        var products = catalogClient->ListProducts(req);
         if (products is grpc:Error) {
-            io:println("Error from Connector: " + products.reason() + " - "
+            log:printError("Error when retrieving products: " + products.reason() + " - "
             + <string>products.detail()["message"]);
 
-            // You should return a ListRecommendationsResponse
-            ListRecommendationsRequest resp = {
+            // Return a fixed set of recommendations on error.
+            ListRecommendationsRequest response = {
                 user_id: value.user_id,
                 product_ids: ["9SIQT8TOJO", "6E92ZMYYFZ", "LS4PSXUNUM"]
             };
-            io:println(resp);
-            var e = caller->send(resp);
+            var e = caller->send(response);
             e = caller->complete();
+
+            if (e is error) {
+                log:printError("Error when sending recommendations: " + e.reason() + " - "
+                + <string>e.detail()["message"]);
+            }
         } else {
-            ListProductsResponse listProductResponse;
-            grpc:Headers headers;
-            [listProductResponse, headers] = products;
+            // Get the ListProductResponse from the union typed value.
+            ListProductsResponse listProductResponse = products[0];
             Product[] productList = listProductResponse.products;
             
             // Extract product id from the product list.
             string[] productIds = [];
-            int i = 0;
-            foreach Product v in productList {
-                productIds[i] = v.id;
-                i += 1;
+            foreach Product product in productList {
+                productIds.push(product.id);
             }
 
             // Filter products which already available in the request.
-            string[] filtered_products = [];
-            int j = 0;
-            foreach string item in productIds {
+            string[] filteredProducts = [];
+            foreach string productId in productIds {
                 boolean isExist = false;
-                foreach string v in value.product_ids {
-                    if (item == v) {
+                foreach string availableId in value.product_ids {
+                    if (productId == availableId) {
                         isExist = true;
                     }
                 }
                 if (!isExist) {
-                    filtered_products[j] = item;
-                    j += 1;
+                    filteredProducts.push(productId);
                 }
             }
 
             // Send the list of recommentations
-            ListRecommendationsRequest resp = {
+            ListRecommendationsRequest response = {
                 user_id: value.user_id,
-                product_ids: filtered_products.reverse()
+                product_ids: filteredProducts.reverse()
             };
-            io:println(resp);
-            var e = caller->send(resp);
+            var e = caller->send(response);
             e = caller->complete();
+
+            if (e is error) {
+                log:printError("Error when sending recommendations: " + e.reason() + " - "
+                + <string>e.detail()["message"]);
+            }
         }
     }
 }