修复优惠券足额抵扣报名费后出现的流程问题

YD_Event.Application/Event/UnifiedRegistrationService.cs

@@ -156,11 +156,17 @@ public class UnifiedRegistrationService : ITransient
         registration.TotalPersonCount = totalPersonCount;
         await _registrationRepository.UpdateAsync(registration);
 
-        // 5. 如果是免费赛事，直接完成支付
+        // 5. 如果是免费赛事，直接完成支付（无优惠券，原价即0）
         if (totalAmount <= 0)
         {
             _logger.LogInformation("免费赛事，直接完成支付，报名ID: {RegistrationId}", registration.Id);
-            await HandleFreePaymentAsync(registration, null, input.CreatedUserId);
+            var eventInfo = await _eventRepository.GetByIdAsync(registration.EventId);
+            if (eventInfo == null)
+            {
+                throw Oops.Bah("赛事信息不存在");
+            }
+            await HandleFreePaymentAsync(registration, eventInfo, totalAmount, 0,
+                null, null, null, input.CreatedUserId);
         }
 
         _logger.LogInformation("统一报名处理完成，报名ID: {RegistrationId}", registration.Id);
@@ -286,6 +292,28 @@ public class UnifiedRegistrationService : ITransient
             throw Oops.Bah("赛事信息不存在");
         }
 
+        // 2.1 幂等短路：已成交（含 0 元券全额抵扣）直接返回。
+        // 关键：必须在重新计算金额之前短路。0 元成交时优惠券已被核销(Status=1)，
+        // 若重入再走 CalculateFinalAmountAsync，会因查不到可用券而把 finalAmount 回退为原价，
+        // 从而落入付费分支：覆盖 PaymentStatus(1→0)、重复建单、重复调起微信支付 → 重复扣款/列表不显示。
+        if (registration.PaymentStatus == 1)
+        {
+            _logger.LogInformation("报名已成交，幂等返回，报名ID: {RegistrationId}", registration.Id);
+            var paidOrder = await _orderRepository.GetFirstAsync(o =>
+                o.RegistrationId == registration.Id && !o.DeleteMark);
+            var paidAmount = paidOrder?.ActualAmount ?? 0;
+            return new UnifiedPaymentOutput
+            {
+                RegistrationId = registration.Id,
+                OrderNo = registration.OrderNo,
+                OriginalAmount = paidOrder?.OriginalAmount ?? registration.TotalAmount,
+                DiscountAmount = paidOrder?.DiscountAmount ?? 0,
+                ActualAmount = paidAmount,
+                PaymentStatus = 1,
+                IsFree = paidAmount <= 0
+            };
+        }
+
         // 3. 计算优惠后金额（每次都重新计算，确保金额正确）
         var calculateResult = await CalculateFinalAmountAsync(
             registration.TotalAmount, input.CouponId, input.OperatorUserId);
@@ -308,13 +336,15 @@ public class UnifiedRegistrationService : ITransient
             CouponRuleNote = usedCoupon != null ? "优惠券使用后不予退还" : null
         };
 
-        // 6. 处理免费情况
+        // 6. 处理免费情况（0 元券全额抵扣等）：与付费成交对齐——生成订单+支付流水并完成核销，避免状态孤岛
         if (finalAmount <= 0)
         {
             if (registration.PaymentStatus != 1)
             {
-                await HandleFreePaymentAsync(registration, usedUserCoupon, input.OperatorUserId);
+                await HandleFreePaymentAsync(registration, eventInfo, originalAmount, discountAmount,
+                    input.CouponId, usedCoupon, usedUserCoupon, input.OperatorUserId);
             }
+            output.OrderNo = registration.OrderNo;
             output.PaymentStatus = 1;
             return output;
         }
@@ -954,24 +984,98 @@ public class UnifiedRegistrationService : ITransient
     }
 
     /// <summary>
-    /// 处理免费支付
+    /// 处理免费支付（0 元券全额抵扣 / 免费赛事成交）
+    /// 与线上支付回调 <see cref="HandlePaymentSuccessAsync"/> 对齐：
+    /// 生成订单(已支付)+支付流水(金额0)，并完整核销优惠券，避免“付了钱但查不到”的状态孤岛。
     /// </summary>
-    private async Task HandleFreePaymentAsync(EventRegistration registration, YD_Event.Core.Entities.UserCoupon? userCoupon, long operatorUserId)
+    private async Task HandleFreePaymentAsync(
+        EventRegistration registration, EventInfo eventInfo,
+        decimal originalAmount, decimal discountAmount,
+        long? couponId, YD_Event.Core.Entities.Coupon? coupon,
+        YD_Event.Core.Entities.UserCoupon? userCoupon, long operatorUserId)
     {
+        var now = DateTime.Now;
+
+        // 1. 确保有订单号（预报名创建时 OrderNo 为空字符串）
+        if (string.IsNullOrEmpty(registration.OrderNo))
+        {
+            registration.OrderNo = await _orderNoGeneratorService.GenerateOrderNoAsync();
+        }
+
+        // 2. 报名记录置为已支付（免费成交）
+        registration.PaymentStatus = 1;
+        registration.PaymentMethod = 2; // 免费赛事统一按线上支付方式，满足小程序列表放行条件
+        registration.PaymentMethodType = PaymentMethodType.WeChatPay;
+        registration.PaymentTime = now;
+        registration.UpdatedTime = now;
+        registration.UpdatedUserId = operatorUserId;
+        await _registrationRepository.UpdateAsync(registration);
+
+        // 3. 生成订单并标记为已支付（实付 0），消除状态孤岛
+        var order = await CreateOrderAsync(registration, eventInfo, originalAmount, discountAmount,
+            0, couponId, operatorUserId);
+        order.OrderStatus = OrderStatus.Paid;
+        order.PaymentTime = now;
+        order.UpdatedTime = now;
+        await _orderRepository.UpdateAsync(order);
+
+        // 4. 写支付流水（金额 0），与微信回调路径保持一致
+        var payment = new EventRegistrationPayment
+        {
+            Id = _idGenerator.NewLong(),
+            RegistrationId = registration.Id,
+            TransactionNo = "",
+            PaymentChannel = 1,
+            PaymentAmount = 0,
+            PaymentTime = now,
+            PaymentStatus = 1,
+            RefundStatus = 0,
+            PayeeAccount = "",
+            CreatedUserId = registration.CreatedUserId,
+            CreatedTime = now
+        };
+        await _paymentRepository.InsertAsync(payment);
+
+        // 5. 完整核销优惠券（补齐 OrderId / UsedQuantity / 兑换码，与银行转账、微信回调路径一致）
         if (userCoupon != null)
         {
             userCoupon.Status = 1;
-            userCoupon.UseTime = DateTime.Now;
+            userCoupon.UseTime = now;
+            userCoupon.OrderId = order.Id;
+            userCoupon.UpdatedTime = now;
+            userCoupon.UpdatedUserId = operatorUserId;
             await _userCouponRepository.UpdateAsync(userCoupon);
+
+            // 兑换码标记已使用
+            if (userCoupon.RedemptionCodeId.HasValue)
+            {
+                var redemptionCode = await _redemptionCodeRepository.GetFirstAsync(rc =>
+                    rc.Id == userCoupon.RedemptionCodeId.Value && rc.Status == 0 && !rc.DeleteMark);
+                if (redemptionCode != null)
+                {
+                    redemptionCode.Status = 1;
+                    redemptionCode.UsedTime = now;
+                    redemptionCode.UpdatedTime = now;
+                    redemptionCode.UpdatedUserId = operatorUserId;
+                    await _redemptionCodeRepository.UpdateAsync(redemptionCode);
+                }
+            }
+
+            // 优惠券已使用数量 +1
+            var couponEntity = coupon ?? (couponId.HasValue
+                ? await _couponRepository.GetByIdAsync(couponId.Value)
+                : null);
+            if (couponEntity != null)
+            {
+                couponEntity.UsedQuantity++;
+                couponEntity.UpdatedTime = now;
+                couponEntity.UpdatedUserId = operatorUserId;
+                await _couponRepository.UpdateAsync(couponEntity);
+            }
         }
 
-        registration.PaymentStatus = 1;
-        registration.PaymentMethod = 2; // 免费赛事设置为线上支付方式
-        registration.PaymentMethodType = PaymentMethodType.WeChatPay; // 默认微信支付
-        registration.PaymentTime = DateTime.Now;
-        registration.UpdatedTime = DateTime.Now;
-        registration.UpdatedUserId = operatorUserId;
-        await _registrationRepository.UpdateAsync(registration);
+        _logger.LogInformation("免费成交处理完成（0元/券全额抵扣），报名ID: {RegistrationId}, 订单号: {OrderNo}",
+            registration.Id, registration.OrderNo);
     }
 
     /// <summary>