fix: 问题修复

src/utils/coupon-utils.js

@@ -181,8 +181,15 @@ export function returnCouponCanUse(args) {
       };
     }
   }
+
   // 商品兑换券，第二件半价和买一送一判断是否有可用商品
   if ([2, 4, 5].includes(coupon.type)) {
+    if (coupon.type == 2 && fullAmount < coupon.fullAmount) {
+      return {
+        canUse: false,
+        reason: `满${coupon.fullAmount}元可用，当前可参与金额${fullAmount}元`,
+      };
+    }
     // 没有符合条件的商品
     if (isDikouAll && canDikouGoodsArr.length === 0) {
       return {
@@ -265,12 +272,14 @@ export function calcDiscountGoodsArrPrice(discountGoodsArr, discountNum, user, s
     const shengyuNum = discountNum - hasCountNum;
     const num = Math.min(goods.num, shengyuNum);
     discountPrice += returnGoodsPrice(goods, user, shopInfo) * num;
+
     hasCountNum += num;
     hasDiscountGoodsArr.push({
       ...goods,
       num,
     });
   }
+
   return {
     discountPrice,
     hasDiscountGoodsArr,
@@ -330,7 +339,6 @@ export function returnCouponZhekouDiscount(
 
   // 将商品订单价格转换为BigNumber并减去优惠券折扣
   const adjustedGoodsOrderPrice = new BigNumber(goodsOrderPrice).minus(goodsCouponDiscount);
-  console.log("adjustedGoodsOrderPrice", adjustedGoodsOrderPrice.toNumber());
 
   // 计算优惠比例：(100 - 折扣率) / 100
   const discountAmountRatio = new BigNumber(100).minus(discountRate).dividedBy(100);
@@ -366,9 +374,7 @@ export function returnCouponProductDiscount(canDikouGoodsArr, coupon, user, shop
   //抵扣全部商品
   if (useFoods.length === 0) {
     if (useRule == "price_asc") {
-      discountGoodsArr = canDikouGoodsArr
-        .slice(canDikouGoodsArr.length - discountNum, canDikouGoodsArr.length)
-        .reverse();
+      discountGoodsArr = canDikouGoodsArr.slice(discountNum * -1).reverse();
     } else {
       discountGoodsArr = canDikouGoodsArr.slice(0, discountNum);
     }
@@ -378,9 +384,7 @@ export function returnCouponProductDiscount(canDikouGoodsArr, coupon, user, shop
       useFoods.find((food) => food.id == v.productId)
     );
     if (useRule == "price_asc") {
-      discountGoodsArr = discountSelGoodsArr
-        .slice(discountSelGoodsArr.length - discountNum, discountSelGoodsArr.length)
-        .reverse();
+      discountGoodsArr = discountSelGoodsArr.slice(discountNum * -1).reverse();
     } else {
       discountGoodsArr = discountSelGoodsArr.slice(0, discountNum);
     }

src/utils/goods.ts

@@ -1707,12 +1707,17 @@ export function calculateOrderCostSummary(
   }
 
   // 5. 最终实付金额计算（整合所有费用）
-  const finalPayAmount = new BigNumber(goodsOriginalAmount) // 商品原价总和
+  // 先计算减去所有折扣后的金额，并确保最小值为0
+  const discountedAmount = new BigNumber(goodsOriginalAmount) // 商品原价总和
     .minus(goodsDiscountAmount) // 减去商品折扣
     .minus(couponDeductionAmount) // 减去优惠券抵扣
     .minus(newUserDiscount) // 新客立减
     .minus(pointDeductionAmount) // 减去积分抵扣
-    .minus(merchantReductionActualAmount) // 减去商家实际减免金额
+    .minus(merchantReductionActualAmount); // 减去商家实际减免金额
+
+  // 确保折扣后金额不小于0，再加上后续费用
+  const nonNegativeAmount = discountedAmount.gt(0) ? discountedAmount : new BigNumber(0);
+  const finalPayAmount = nonNegativeAmount
     .plus(seatFee) // 加上餐位费（不参与减免）
     .plus(packFee) // 加上打包费（不参与减免）
     .plus(additionalFee); // 加上附加费