Update the instructions and the answer of the Ballerina billionare exercise

exercises/practice/http-billion-dollar-question/.docs/instructions.md

@@ -4,19 +4,20 @@
 
 You have been asked to find the top `x` billionaires by net worth in a given set of countries (number of countries = `N`). To implement that, you have been given access to an API that returns the details of the billionaires by country.
 
-To simplify accessing the API, you can use the [`ims/billionairehub` client](https://lib.ballerina.io/ims/billionairehub/1.0.0/clients/Client) connector to connect to the API which returns details of the billionaires by country.
+To simplify accessing the API, you can use a predefined client connector to connect to the API which returns details of the billionaires by country.
 
 
 ```ballerina
-import ims/billionairehub;
+import ballerina_exercism/http_billion_dollar_question.billionarehub_server as _;
+import ballerina_exercism/http_billion_dollar_question.billionarehub_client as billionarehubClient;
 
-# Client ID and Client Secret to connect to the billionaire API
-configurable string clientId = ?;
-configurable string clientSecret = ?;
+type Billionaire record {
+    string name;
+    float netWorth;
+};
 
 public function getTopXBillionaires(string[] countries, int x) returns string[]|error {
-    // Create the client connector
-    billionairehub:Client cl = check new ({auth: {clientId, clientSecret}});
+    billionarehubClient:BillionareClient cl = check new();
 
     // TODO Write your logic here
     return [];
@@ -55,16 +56,15 @@ Limit: 5
 Output
 
 ```
-["Mukesh Ambani", "Gautam Adani & family", "Zhong Shanshan", "Zhang Yiming", "Ma Huateng"]
+["Mukesh Ambani","Zhong Shanshan","Ma Huateng","Colin Huang","Pony Ma"]
 ```
 
 ## Test Environment
 
-* Client ID and Client Secret to connect to the billionaire API have been provided to you in the `tests/Config.toml`. You can use them to initialize the client.
 * Use `bal test` to run and test your implementation.
 
 ## Hints
 
-* `ims/billionairehub` package's [client](https://lib.ballerina.io/ims/billionairehub/1.0.0/clients/Client) can be used to invoke the get billionaires by country API. You can use the `getBillionaires("<country>")` remote method specifically.
+* `http_billion_dollar_question` package's `billionarehub_client` module can be used to invoke the get billionaires by country API. You can use the `getBillionaires("<country>")` remote method specifically.
 * You can find the richest people per country first and then combine them to find the top `x`
 * [Query expressions](https://ballerina.io/learn/by-example/query-expressions/) will be convenient for filtering and sorting

exercises/practice/http-billion-dollar-question/.meta/config.json

@@ -19,5 +19,5 @@
   "icon": "elons-toys",
   "blurb": "Can you find the top billionaires by net worth in a given set of countries?",
   "source": "This is an exercise to introduce users to using Ballerina HTTP service data binding",
-  "source_url": "https://ballerina.io/learn/by-example/http-data-binding"
+  "source_url": "https://ballerina.io/learn/by-example/http-service-data-binding/"
 }

exercises/practice/http-billion-dollar-question/.meta/reference/main.bal

@@ -1,24 +1,13 @@
-import ballerina/io;
-import ims/billionairehub;
+import ballerina_exercism/http_billion_dollar_question.billionarehub_server as _;
+import ballerina_exercism/http_billion_dollar_question.billionarehub_client as billionarehubClient;
 
-configurable string clientId = ?;
-configurable string clientSecret = ?;
-
-public function main() returns error? {
-    billionairehub:Client cl = check new ({auth: {clientId, clientSecret}});
-    billionairehub:Billionaire[] billionaires = check cl->getBillionaires("France");
-    io:println(billionaires);
-
-    map<boolean> industries = {};
-    check from var b in billionaires
-        do {
-            industries[b.industry] = true;
-        };
-    io:println(industries.keys());
-}
+type Billionaire record {
+    string name;
+    float netWorth;
+};
 
 public function getTopXBillionaires(string[] countries, int x) returns string[]|error {
-    billionairehub:Billionaire[] billionaires = [];
+    Billionaire[] billionaires = [];
     foreach string country in countries {
         billionaires.push(...check getTopXBillionairesByCountry(country, x));
     }
@@ -29,11 +18,11 @@ public function getTopXBillionaires(string[] countries, int x) returns string[]|
         select b.name;
 }
 
-function getTopXBillionairesByCountry(string country, int x) returns billionairehub:Billionaire[]|error {
-    billionairehub:Client cl = check new ({auth: {clientId, clientSecret}});
-    billionairehub:Billionaire[] billionaires = check cl->getBillionaires(country);
+function getTopXBillionairesByCountry(string country, int x) returns Billionaire[]|error {
+    billionarehubClient:BillionareClient cl = check new();
+    Billionaire[] billionaires = check cl->getBillionaires(country);
     return from var b in billionaires
         order by b.netWorth descending
         limit x
         select b;
-}
+}

exercises/practice/http-billion-dollar-question/main.bal

@@ -1,12 +1,18 @@
-import ims/billionairehub;
+import ballerina_exercism/http_billion_dollar_question.billionarehub_server as _;
+import ballerina_exercism/http_billion_dollar_question.billionarehub_client as billionarehubClient;
 
-# Client ID and Client Secret to connect to the billionaire API
-configurable string clientId = ?;
-configurable string clientSecret = ?;
+type Billionaire record {
+    string name;
+    float netWorth;
+};
 
+# Returns the top billionares of the given countries.
+#
+# + countries - countries to search for billionares
+# + x - number of billionares to return
+# + return - list of billionares
 public function getTopXBillionaires(string[] countries, int x) returns string[]|error {
-    // Create the client connector
-    billionairehub:Client cl = check new ({auth: {clientId, clientSecret}});
+    billionarehubClient:BillionareClient cl = check new();
 
     // TODO Write your logic here
     return [];

exercises/practice/http-billion-dollar-question/modules/billionarehub_client/client.bal

@@ -0,0 +1,20 @@
+import ballerina/http;
+
+type Billionaire record {
+    string name;
+    float netWorth;
+};
+
+const string clientUrl = "http://localhost:9090";
+
+public client class BillionareClient {
+    private final http:Client httpClient;
+
+    public function init() returns error? {
+        self.httpClient = check new (clientUrl);
+    }
+
+    remote function getBillionaires(string country) returns Billionaire[]|error {
+        return self.httpClient->/getBillionaires(country=country);
+    }
+}