evshop_api/app/common/payment/Payment.php

<?php
namespace app\common\payment;

use app\common\payment\PaymentFactory;

class Payment
{
    private $paymentGateway;

    public function __construct($pay_code){
        $this->paymentGateway = PaymentFactory::createPaymentService($pay_code);
    }

    public function pay($order){
        return $this->paymentGateway->pay($order);
    }

    public function response($data){
        return $this->paymentGateway->response($data);
    }

    public function callback($data){
        return $this->paymentGateway->callback($data);
    }
}