common interface that all payment gateway clients will implement

payment-service/src/main/java/com/finpay/payment_service/gateways/PaymentGateway.java

@@ -0,0 +1,25 @@
+package com.finpay.payment_service.gateways;
+
+import com.finpay.payment_service.dtos.PaymentRequest;
+import com.finpay.payment_service.dtos.PaymentGatewayResponse;
+import com.finpay.payment_service.dtos.RefundRequest;
+import com.finpay.payment_service.dtos.RefundGatewayResponse;
+
+public interface PaymentGateway {
+
+    /**
+     * Processes a payment through the specific gateway.
+     *
+     * @param paymentRequest The payment details.
+     * @return The response from the payment gateway.
+     */
+    PaymentGatewayResponse processPayment(PaymentRequest paymentRequest);
+
+    /**
+     * Processes a refund through the specific gateway.
+     *
+     * @param refundRequest The refund details.
+     * @return The response from the refund gateway.
+     */
+    RefundGatewayResponse processRefund(RefundRequest refundRequest);
+}