From 9b38e44e1d084b93ada34bc29583983e430dc7d9 Mon Sep 17 00:00:00 2001
From: erio <asakifeng@gmail.com>
Date: Fri, 10 Apr 2026 14:27:44 +0800
Subject: [PATCH] fix(payment): restore double URL decode for EasyPay webhook
 values

EasyPay callbacks arrive with double-encoded query values (e.g. %25E5 instead
of %E5) due to redirect chains. url.ParseQuery decodes once; decodeURLValue
applies a second safe decode so the sign matches what EasyPay computed.
Also removes temporary debug logging.
---
 backend/internal/handler/payment_webhook_handler.go | 3 ++-
 backend/internal/payment/provider/easypay.go        | 9 ++++-----
 backend/internal/service/payment_service.go         | 7 +------
 3 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/backend/internal/handler/payment_webhook_handler.go b/backend/internal/handler/payment_webhook_handler.go
index b923a2a9a2..6d8540d80b 100644
--- a/backend/internal/handler/payment_webhook_handler.go
+++ b/backend/internal/handler/payment_webhook_handler.go
@@ -95,7 +95,8 @@ func (h *PaymentWebhookHandler) handleNotify(c *gin.Context, providerKey string)
 		if len(truncatedBody) > webhookLogTruncateLen {
 			truncatedBody = truncatedBody[:webhookLogTruncateLen] + "...(truncated)"
 		}
-		slog.Error("[Payment Webhook] verify failed", "provider", providerKey, "error", err, "method", c.Request.Method, "bodyLen", len(rawBody), "rawBody", truncatedBody)
+		slog.Error("[Payment Webhook] verify failed", "provider", providerKey, "error", err, "method", c.Request.Method, "bodyLen", len(rawBody))
+		slog.Debug("[Payment Webhook] verify failed body", "provider", providerKey, "rawBody", truncatedBody)
 		c.String(http.StatusBadRequest, "verify failed")
 		return
 	}
diff --git a/backend/internal/payment/provider/easypay.go b/backend/internal/payment/provider/easypay.go
index a203aaf615..5d3c4b8bfb 100644
--- a/backend/internal/payment/provider/easypay.go
+++ b/backend/internal/payment/provider/easypay.go
@@ -9,7 +9,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"log/slog"
 	"net/http"
 	"net/url"
 	"sort"
@@ -177,18 +176,18 @@ func (e *EasyPay) VerifyNotification(_ context.Context, rawBody string, _ map[st
 	if err != nil {
 		return nil, fmt.Errorf("parse notify: %w", err)
 	}
-	// url.ParseQuery already decodes values — no additional decode needed.
+	// EasyPay callbacks may arrive with double-encoded values (e.g. via redirect
+	// chains), so url.ParseQuery decodes once, then decodeURLValue decodes again.
+	// If a value is NOT double-encoded, QueryUnescape returns it unchanged.
 	params := make(map[string]string)
 	for k := range values {
-		params[k] = values.Get(k)
+		params[k] = decodeURLValue(values.Get(k))
 	}
 	sign := params["sign"]
 	if sign == "" {
 		return nil, fmt.Errorf("missing sign")
 	}
 	if !easyPayVerifySign(params, e.config["pkey"], sign) {
-		expected := easyPaySign(params, e.config["pkey"])
-		slog.Error("[EasyPay] sign mismatch", "expected", expected, "got", sign, "pkeyLen", len(e.config["pkey"]), "instanceID", e.instanceID, "paramCount", len(params))
 		return nil, fmt.Errorf("invalid signature")
 	}
 	status := payment.ProviderStatusFailed
diff --git a/backend/internal/service/payment_service.go b/backend/internal/service/payment_service.go
index cb78111790..25ec15f748 100644
--- a/backend/internal/service/payment_service.go
+++ b/backend/internal/service/payment_service.go
@@ -229,15 +229,10 @@ func (s *PaymentService) GetWebhookProvider(ctx context.Context, providerKey, ou
 		if err == nil {
 			p, pErr := s.getOrderProvider(ctx, order)
 			if pErr == nil {
-				slog.Info("[Webhook] using order's provider instance", "outTradeNo", outTradeNo, "instanceID", order.ProviderInstanceID, "providerKey", p.ProviderKey())
 				return p, nil
 			}
-			slog.Warn("[Webhook] order provider creation failed, falling back to registry", "outTradeNo", outTradeNo, "instanceID", order.ProviderInstanceID, "error", pErr)
-		} else {
-			slog.Warn("[Webhook] order lookup failed", "outTradeNo", outTradeNo, "error", err)
+			slog.Warn("[Webhook] order provider creation failed, falling back to registry", "outTradeNo", outTradeNo, "error", pErr)
 		}
-	} else {
-		slog.Info("[Webhook] no out_trade_no extracted, using registry", "providerKey", providerKey)
 	}
 	s.EnsureProviders(ctx)
 	return s.registry.GetProviderByKey(providerKey)