feat(tiered-pricing): [outside-in] move fake to use case

Author: santakadev

exercises/tiered_pricing/solutions/codely_outside-in/src/main/java/tv/codely/checkout/CalculateSubscriptionsPrice.java

@@ -0,0 +1,7 @@
+package tv.codely.checkout;
+
+public class CalculateSubscriptionsPrice {
+    public int execute(String subscriptions) {
+        return 199;
+    }
+}

exercises/tiered_pricing/solutions/codely_outside-in/src/main/java/tv/codely/checkout/api/Controller/SubscriptionTotalGetController.java

@@ -6,6 +6,7 @@
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
+import tv.codely.checkout.CalculateSubscriptionsPrice;
 
 import javax.servlet.http.HttpServletResponse;
 
@@ -16,6 +17,10 @@ public class SubscriptionTotalGetController {
     public ResponseEntity<String> response(@RequestParam String subscriptions, HttpServletResponse response) throws JSONException {
         response.addHeader("content-type", "application/json");
 
-        return ResponseEntity.ok(new JSONObject().put("total", 199).toString());
+        var calculateSubscriptionsPrice = new CalculateSubscriptionsPrice();
+
+        int total = calculateSubscriptionsPrice.execute(subscriptions);
+
+        return ResponseEntity.ok(new JSONObject().put("total", total).toString());
     }
 }