From c796623148fcb3cd142a369f27edd70cbdcb886f Mon Sep 17 00:00:00 2001
From: Cursor Agent <cursoragent@cursor.com>
Date: Tue, 8 Jul 2025 15:18:11 +0000
Subject: [PATCH] Improve coupon template take count with stock validation
 logic

Co-authored-by: zhijiantianya <zhijiantianya@gmail.com>
---
 .../dal/mysql/coupon/CouponTemplateMapper.java   | 16 ++++++++++++----
 .../service/coupon/CouponServiceImpl.java        |  8 ++------
 .../coupon/CouponTemplateServiceImpl.java        |  7 ++++++-
 3 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/dal/mysql/coupon/CouponTemplateMapper.java b/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/dal/mysql/coupon/CouponTemplateMapper.java
index 3096a49f3c..01d079a0e5 100755
--- a/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/dal/mysql/coupon/CouponTemplateMapper.java
+++ b/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/dal/mysql/coupon/CouponTemplateMapper.java
@@ -40,10 +40,18 @@ public interface CouponTemplateMapper extends BaseMapperX<CouponTemplateDO> {
                 .orderByDesc(CouponTemplateDO::getId));
     }
 
-    default void updateTakeCount(Long id, Integer incrCount) {
-        update(null, new LambdaUpdateWrapper<CouponTemplateDO>()
-                .eq(CouponTemplateDO::getId, id)
-                .setSql("take_count = take_count + " + incrCount));
+    default int updateTakeCount(Long id, Integer incrCount) {
+        LambdaUpdateWrapper<CouponTemplateDO> wrapper = new LambdaUpdateWrapper<CouponTemplateDO>()
+                .eq(CouponTemplateDO::getId, id);
+        
+        // 只在增加数量时检查库存（incrCount > 0）
+        if (incrCount > 0) {
+            // 添加库存判断：剩余数量 >= 领取的数量，或者总数量为-1（无限库存）
+            wrapper.and(w -> w.apply("total_count = -1 OR (total_count - take_count) >= {0}", incrCount));
+        }
+        
+        wrapper.setSql("take_count = take_count + " + incrCount);
+        return update(null, wrapper);
     }
 
     default List<CouponTemplateDO> selectListByTakeType(Integer takeType) {
diff --git a/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/service/coupon/CouponServiceImpl.java b/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/service/coupon/CouponServiceImpl.java
index e6f82a69fc..3d6021e521 100644
--- a/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/service/coupon/CouponServiceImpl.java
+++ b/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/service/coupon/CouponServiceImpl.java
@@ -279,12 +279,8 @@ public class CouponServiceImpl implements CouponService {
         if (ObjUtil.notEqual(couponTemplate.getTakeType(), takeType.getType())) {
             throw exception(COUPON_TEMPLATE_CANNOT_TAKE);
         }
-        // 校验发放数量不能过小（仅在 CouponTakeTypeEnum.USER 用户领取时）
-        if (CouponTakeTypeEnum.isUser(couponTemplate.getTakeType())
-                && ObjUtil.notEqual(couponTemplate.getTakeLimitCount(), CouponTemplateDO.TIME_LIMIT_COUNT_MAX) // 非不限制
-                && couponTemplate.getTakeCount() + userIds.size() > couponTemplate.getTotalCount()) {
-            throw exception(COUPON_TEMPLATE_NOT_ENOUGH);
-        }
+        // 注意：库存检查现在在数据库层面的 updateCouponTemplateTakeCount 方法中进行
+        // 如果库存不足，该方法会抛出 COUPON_TEMPLATE_NOT_ENOUGH 异常
         // 校验"固定日期"的有效期类型是否过期
         if (CouponTemplateValidityTypeEnum.DATE.getType().equals(couponTemplate.getValidityType())) {
             if (LocalDateTimeUtils.beforeNow(couponTemplate.getValidEndTime())) {
diff --git a/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/service/coupon/CouponTemplateServiceImpl.java b/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/service/coupon/CouponTemplateServiceImpl.java
index 175e33b197..cc2fd6027b 100755
--- a/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/service/coupon/CouponTemplateServiceImpl.java
+++ b/yudao-module-mall/yudao-module-promotion/src/main/java/cn/iocoder/yudao/module/promotion/service/coupon/CouponTemplateServiceImpl.java
@@ -23,6 +23,7 @@ import java.util.Objects;
 
 import static cn.iocoder.yudao.framework.common.exception.util.ServiceExceptionUtil.exception;
 import static cn.iocoder.yudao.module.promotion.enums.ErrorCodeConstants.COUPON_TEMPLATE_NOT_EXISTS;
+import static cn.iocoder.yudao.module.promotion.enums.ErrorCodeConstants.COUPON_TEMPLATE_NOT_ENOUGH;
 import static cn.iocoder.yudao.module.promotion.enums.ErrorCodeConstants.COUPON_TEMPLATE_TOTAL_COUNT_TOO_SMALL;
 
 /**
@@ -116,7 +117,11 @@ public class CouponTemplateServiceImpl implements CouponTemplateService {
 
     @Override
     public void updateCouponTemplateTakeCount(Long id, int incrCount) {
-        couponTemplateMapper.updateTakeCount(id, incrCount);
+        int updateCount = couponTemplateMapper.updateTakeCount(id, incrCount);
+        // 只在增加数量且更新失败时，说明库存不足，抛出异常
+        if (incrCount > 0 && updateCount == 0) {
+            throw exception(COUPON_TEMPLATE_NOT_ENOUGH);
+        }
     }
 
     @Override