Separated laravel app to its own folder (#540)

api/app/Service/BillingHelper.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace App\Service;
+
+use Illuminate\Support\Facades\App;
+use Stripe\SubscriptionItem;
+
+class BillingHelper
+{
+    public static function getPricing($productName = 'default')
+    {
+        return App::environment() == 'production' ?
+            config('pricing.production.' . $productName . '.pricing') :
+            config('pricing.test.' . $productName . '.pricing');
+    }
+
+    public static function getProductId($productName = 'default')
+    {
+        return App::environment() == 'production' ?
+            config('pricing.production.' . $productName . '.product_id') :
+            config('pricing.test.' . $productName . '.product_id');
+    }
+
+    public static function getLineItemInterval(SubscriptionItem $item)
+    {
+        return $item->price->recurring->interval === 'year' ? 'yearly' : 'monthly';
+        ;
+    }
+}