Product add method present

src/pay_center/Product.php

@@ -53,4 +53,20 @@ class Product implements IAssignable {
     public static function hasBought(string $name, int $userId): bool {
         return array_key_exists($name, self::userBought($userId));
     }
+
+    /**
+     * @param int    $userId
+     * @param string $comment
+     *
+     * @return Order
+     */
+    public function present(int $userId, string $comment = '') {
+        $purpose = new Purpose();
+        $purpose->productName = $this->name;
+        $purpose->payMethod = Order::PAY_PRESENT;
+        $purpose->userId = $userId;
+        $purpose->comment = $comment;
+        $purpose->money = 0;
+        return RPCWrapper::rpc('pay_center')->call('buy', $purpose);
+    }
 }
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