feat(sca): return 202 + 3ds redirect token when checkout requires auth

api/handlers/cart.go

@@ -24,11 +24,12 @@ import (
 
 type CartHandler struct {
 	stripeKey string
+	appURL    string
 }
 
 // NewCartHandler creates a new cart handler with the Stripe secret key
-func NewCartHandler(stripeSecretKey string) *CartHandler {
-	return &CartHandler{stripeKey: stripeSecretKey}
+func NewCartHandler(stripeSecretKey, appURL string) *CartHandler {
+	return &CartHandler{stripeKey: stripeSecretKey, appURL: appURL}
 }
 
 // getOrCreateCart finds the users cart or creates one.
@@ -424,8 +425,12 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 	stripeDur := time.Since(stripeStart).Seconds()
 	if err != nil {
 		middleware.ObserveStripeRequest("payment_intent_create", "error", stripeDur)
-		db.Model(&order).Update("status", models.OrderStatusFailed)
 		if stripeErr, ok := err.(*stripe.Error); ok {
+			if stripeErr.Code == stripe.ErrorCodeAuthenticationRequired && stripeErr.PaymentIntent != nil {
+				h.respondRequiresAction(w, &order, stripeErr.PaymentIntent)
+				return
+			}
+			db.Model(&order).Update("status", models.OrderStatusFailed)
 			switch stripeErr.Type {
 			case stripe.ErrorTypeCard:
 				middleware.RecordCartConversion("card_declined")
@@ -442,6 +447,7 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 			}
 			return
 		}
+		db.Model(&order).Update("status", models.OrderStatusFailed)
 		middleware.RecordCartConversion("stripe_error")
 		audit.OrderFailed(userID, order.ID, total, err.Error())
 		utils.RespondError(w, http.StatusInternalServerError, "PAYMENT_FAILED", "payment failed", nil)
@@ -449,6 +455,11 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 	}
 	middleware.ObserveStripeRequest("payment_intent_create", "success", stripeDur)
 
+	if pi.Status == stripe.PaymentIntentStatusRequiresAction {
+		h.respondRequiresAction(w, &order, pi)
+		return
+	}
+
 	// Commit payment ID and clear cart in a single transaction.
 	txErr := db.Transaction(func(tx *gorm.DB) error {
 		order.StripePaymentID = pi.ID
@@ -491,6 +502,46 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+// respondRequiresAction handles a PaymentIntent that needs 3DS auth
+// The order stays pending. the webhook flips it to paid once the customer
+// completes the bank-hosted challenge, the tui polls /api/v1/orders/{id}/status
+func (h *CartHandler) respondRequiresAction(w http.ResponseWriter, order *models.Order, pi *stripe.PaymentIntent) {
+	db := database.GetDB()
+
+	if pi.NextAction == nil || pi.NextAction.RedirectToURL == nil || pi.NextAction.RedirectToURL.URL == "" {
+		middleware.RecordCartConversion("sca_missing_next_action")
+		db.Model(order).Update("status", models.OrderStatusFailed)
+		audit.OrderFailed(order.UserID, order.ID, order.Total, "stripe returned requires_action without redirect url")
+		utils.RespondError(w, http.StatusBadGateway, "PAYMENT_FAILED", "stripe did not return a 3ds url", nil)
+		return
+	}
+
+	// persist the paymentIntent id before responding so the reconciliation jon
+	// and webhook can match the eventual succeeded/failed event to this order
+	// even if the customer drops off mid-auth
+	if err := db.Model(order).Update("stripe_payment_id", pi.ID).Error; err != nil {
+		utils.RespondError(w, http.StatusInternalServerError, "DATABASE_ERROR", "failed to save payment id", nil)
+		return
+	}
+
+	token, err := storeRedirect(pi.NextAction.RedirectToURL.URL)
+	if err != nil {
+		utils.RespondError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "failed to allocate redirect token", nil)
+		return
+	}
+
+	middleware.RecordCartConversion("requires_action")
+	audit.OrderRequiresAction(order.UserID, order.ID, pi.ID)
+
+	utils.RespondSuccess(w, http.StatusAccepted, map[string]any{
+		"order_id":          order.ID,
+		"payment_intent_id": pi.ID,
+		"status":            "requires_action",
+		"redirect_token":    token,
+		"redirect_url":      fmt.Sprintf("%s/pay/%s", h.appURL, token),
+	})
+}
+
 func mapStripeCardErrCode(code stripe.ErrorCode) string {
 	switch code {
 	case stripe.ErrorCodeAuthenticationRequired:

api/handlers/cart_test.go

@@ -65,7 +65,7 @@ func TestGetCartEmpty(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	req := authRequest("GET", "/api/v1/cart", nil, user.ID)
 	w := httptest.NewRecorder()
@@ -104,7 +104,7 @@ func TestSetItemAndGetCart(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	// Add item (CoffeeID=1, Quantity=2)
 	body, _ := json.Marshal(map[string]interface{}{
@@ -160,7 +160,7 @@ func TestSetItemUpdateQuantity(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	// Add item
 	body, _ := json.Marshal(map[string]interface{}{"coffee_id": 1, "quantity": 2})
@@ -205,7 +205,7 @@ func TestSetItemRemove(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	// Add item
 	body, _ := json.Marshal(map[string]interface{}{"coffee_id": 1, "quantity": 3})
@@ -244,7 +244,7 @@ func TestSetItemInvalidProduct(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	body, _ := json.Marshal(map[string]interface{}{"coffee_id": 999, "quantity": 1})
 	req := authRequest("PUT", "/api/v1/cart/item", body, user.ID)
@@ -261,7 +261,7 @@ func TestSetItemMissingCoffeeID(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	body, _ := json.Marshal(map[string]interface{}{"quantity": 1})
 	req := authRequest("PUT", "/api/v1/cart/item", body, user.ID)
@@ -278,7 +278,7 @@ func TestClearCart(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	// Add two items
 	for _, coffeeID := range []uint{1, 2} {
@@ -334,7 +334,7 @@ func TestSetAddress(t *testing.T) {
 	}
 	db.Create(&addr)
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	body, _ := json.Marshal(map[string]interface{}{"address_id": addr.ID})
 	req := authRequest("PUT", "/api/v1/cart/address", body, user.ID)
@@ -388,7 +388,7 @@ func TestSetAddressWrongUser(t *testing.T) {
 	}
 	db.Create(&addr)
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	body, _ := json.Marshal(map[string]interface{}{"address_id": addr.ID})
 	req := authRequest("PUT", "/api/v1/cart/address", body, user.ID)
@@ -416,7 +416,7 @@ func TestSetCard(t *testing.T) {
 	}
 	db.Create(&card)
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	body, _ := json.Marshal(map[string]interface{}{"card_id": card.ID})
 	req := authRequest("PUT", "/api/v1/cart/card", body, user.ID)
@@ -468,7 +468,7 @@ func TestSetCardWrongUser(t *testing.T) {
 	}
 	db.Create(&card)
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	body, _ := json.Marshal(map[string]interface{}{"card_id": card.ID})
 	req := authRequest("PUT", "/api/v1/cart/card", body, user.ID)
@@ -485,7 +485,7 @@ func TestConvertCartMissingAddress(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	// Add item but no address or card
 	body, _ := json.Marshal(map[string]interface{}{"coffee_id": 1, "quantity": 1})
@@ -508,7 +508,7 @@ func TestConvertCartMissingCard(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 	db := database.GetDB()
 
 	// Add item and address
@@ -539,7 +539,7 @@ func TestConvertCartEmpty(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	// Empty cart convert
 	req := authRequest("POST", "/api/v1/cart/convert", nil, user.ID)
@@ -556,7 +556,7 @@ func TestMultipleItems(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 
 	// Add three different items
 	for i := uint(1); i <= 3; i++ {
@@ -605,7 +605,7 @@ func TestCartIsolation(t *testing.T) {
 	}
 	db.Create(&user2)
 
-	handler := NewCartHandler("")
+	handler := NewCartHandler("", "")
 	r := chi.NewRouter()
 	r.Put("/cart/item", handler.SetItem)
 	r.Get("/cart", handler.GetCart)

api/routes/routes.go

@@ -46,7 +46,7 @@ func SetupRoutes(
 	healthHandler := handlers.NewHealthHandler(version)
 	productHandler := handlers.NewProductHandler()
 	authHandler := handlers.NewAuthHandler(jwtManager, authFingerprintKey)
-	cartHandler := handlers.NewCartHandler(stripeSecretKey)
+	cartHandler := handlers.NewCartHandler(stripeSecretKey, appURL)
 	cardHandler := handlers.NewCardHandler(stripeSecretKey, appURL)
 	orderHandler := handlers.NewOrderHandler(stripeSecretKey, bringAPIUID, bringAPIKey, bringCustomerNumber)
 	addressHandler := handlers.NewAddressHandler(shippoAPIKey, bringAPIUID, bringAPIKey)