fix: 订单折扣金额保存不正确修复

src/main/java/com/chaozhanggui/system/cashierservice/service/CartService.java

@@ -1218,11 +1218,20 @@ public class CartService {
             outRecords.add(tbActivateOutRecord);
             cashierCart.setUseCouponInfo(JSONObject.toJSONString(tbActivateOutRecord));
 
-            couponVo.setFinalDiscountAmount(discountAmount);
             // 优惠券未消耗完毕
             if (balanceCart != null && getCanUseCoupon(couponMap, balanceCart.getProductId()) != null) {
-                discountAmount = reduceProCoupon(couponMap, balanceCart, usedCouponMap, discountAmount, balanceCartList, outRecords, memberId);
+                // 递归调用并累加递归返回的折扣金额
+                discountAmount = discountAmount.add(reduceProCoupon(
+                        couponMap,
+                        balanceCart,
+                        usedCouponMap,
+                        BigDecimal.ZERO, // 避免重复累加，递归时传入新的初始值
+                        balanceCartList,
+                        outRecords,
+                        memberId
+                ));
             }
+            couponVo.setFinalDiscountAmount(discountAmount);
             return discountAmount;
         }
         return discountAmount;
@@ -1260,6 +1269,7 @@ public class CartService {
                 resetCouponList.add(cashierCart);
                 cashierCart.setUserCouponId(null);
             }
+            cashierCart.resetTotalAmount();
             discountAmount = reduceProCoupon(couponMap, cashierCart, usedCouponMap, discountAmount, balanceCartList, outRecords, memberId);
         }