refactor(subscription): tighten payment flow boundaries

src/app/subscription/components/subscription-checkout-button.tsx

@@ -6,12 +6,17 @@
  */
 import { useEffect, useRef, useState } from "react";
 
-import { savePendingEzpayOrder } from "@/lib/payment/pending_payment_order";
+import {
+  getPaymentUrl,
+  getStripeClientSecret,
+  isEzpayPayment,
+  launchEzpayRedirect,
+} from "@/lib/payment/payment_launch";
 import {
   usePaymentDispatch,
   usePaymentState,
 } from "@/stores/payment/payment-context";
-import { AppEnvUtil, Logger, Result } from "@/utils";
+import { AppEnvUtil, Logger } from "@/utils";
 
 import { StripePaymentDialog } from "./stripe-payment-dialog";
 import dialogStyles from "./stripe-payment-dialog.module.css";
@@ -69,7 +74,7 @@ export function SubscriptionCheckoutButton({
           orderId: payment.currentOrderId,
           paymentUrl,
           subscriptionType,
-          returnTo,
+          returnTo: returnTo ?? undefined,
           onFailed: (errorMessage) =>
             paymentDispatch({ type: "PaymentLaunchFailed", errorMessage }),
         });
@@ -159,7 +164,7 @@ export function SubscriptionCheckoutButton({
       orderId: payment.currentOrderId,
       paymentUrl: ezpayPaymentUrl,
       subscriptionType,
-      returnTo,
+      returnTo: returnTo ?? undefined,
       onFailed: (errorMessage) => {
         setIsConfirmingEzpay(false);
         paymentDispatch({ type: "PaymentLaunchFailed", errorMessage });
@@ -219,97 +224,6 @@ export function SubscriptionCheckoutButton({
   );
 }
 
-function getPaymentUrl(payParams: Record<string, unknown>): string | null {
-  const keys = [
-    "cashierUrl",
-    "cashier_url",
-    "checkoutUrl",
-    "checkout_url",
-    "paymentUrl",
-    "payment_url",
-    "approvalUrl",
-    "approval_url",
-    "redirectUrl",
-    "redirect_url",
-    "url",
-  ];
-
-  for (const key of keys) {
-    const value = payParams[key];
-    if (typeof value === "string" && value.length > 0) return value;
-  }
-
-  return null;
-}
-
-function isEzpayPayment(payParams: Record<string, unknown>): boolean {
-  const provider = payParams.provider;
-  return typeof provider === "string" && provider.toLowerCase() === "ezpay";
-}
-
-interface RedirectToEzpayInput {
-  orderId: string | null;
-  paymentUrl: string;
-  subscriptionType: "vip" | "topup";
-  returnTo?: "chat" | null;
-  onFailed: (errorMessage: string) => void;
-}
-
-async function launchEzpayRedirect({
-  orderId,
-  paymentUrl,
-  subscriptionType,
-  returnTo,
-  onFailed,
-}: RedirectToEzpayInput): Promise<void> {
-  log.debug("[subscription-checkout] launchEzpayRedirect START", {
-    hasOrderId: Boolean(orderId),
-    orderId,
-    subscriptionType,
-    paymentUrl,
-  });
-
-  if (!orderId) {
-    const errorMessage = "Missing order id before opening Ezpay.";
-    log.error("[subscription-checkout] pending ezpay order save skipped", {
-      subscriptionType,
-      paymentUrl,
-      errorMessage,
-    });
-    onFailed(errorMessage);
-    return;
-  }
-
-  const saveResult = await savePendingEzpayOrder({
-    orderId,
-    subscriptionType,
-    ...(returnTo ? { returnTo } : {}),
-  });
-  if (Result.isErr(saveResult)) {
-    const errorMessage =
-      "Could not save payment order before opening Ezpay. Please try again.";
-    log.error("[subscription-checkout] pending ezpay order save failed", {
-      orderId,
-      subscriptionType,
-      error: saveResult.error,
-    });
-    onFailed(errorMessage);
-    return;
-  }
-
-  log.debug("[subscription-checkout] pending ezpay order saved", {
-    orderId,
-    subscriptionType,
-  });
-
-  log.debug("[subscription-checkout] launchEzpayRedirect NOW", {
-    orderId,
-    subscriptionType,
-    paymentUrl,
-  });
-  window.location.href = paymentUrl;
-}
-
 interface EzpayRedirectConfirmDialogProps {
   orderId: string;
   isConfirming: boolean;
@@ -363,22 +277,3 @@ function EzpayRedirectConfirmDialog({
     </div>
   );
 }
-
-function getStripeClientSecret(
-  payParams: Record<string, unknown>,
-): string | null {
-  const provider = payParams.provider;
-  const clientSecret = payParams.clientSecret ?? payParams.client_secret;
-  const isStripeProvider =
-    typeof provider !== "string" || provider.toLowerCase() === "stripe";
-
-  if (
-    isStripeProvider &&
-    typeof clientSecret === "string" &&
-    clientSecret.length > 0
-  ) {
-    return clientSecret;
-  }
-
-  return null;
-}