refactor(mall): 优化优惠券计算逻辑

KKSU

2024-12-31 f7d41b7891ea7cb9773f4cb415df0234c177ec0b

refactor(mall): 优化优惠券计算逻辑

- 重构了 getCouponAmountMap 方法，提高了代码可读性和维护性
- 使用 Optional 类处理可能为空的对象，增加了代码的健壮性
- 优化了集合操作，提高了代码效率
- 改进了 BigDecimal 的使用方式，确保了精度的准确性

 src/main/java/cc/mrbird/febs/mall/service/impl/ApiMallOrderInfoServiceImpl.java

@@ -42,6 +42,7 @@
import org.springframework.transaction.annotation.Transactional;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.*;
import java.util.stream.Collectors;

@@ -285,75 +286,84 @@
    @Override
    public Map<Long,BigDecimal> getCouponAmountMap(Long memberCouponId,List<AddOrderItemDto> items){
        HashMap<Long,BigDecimal> couponAmountMap = new HashMap<>();
        MallMemberCoupon mallMemberCoupon = mallMemberCouponMapper.selectById(memberCouponId);
        if(ObjectUtil.isEmpty(mallMemberCoupon)){
        // 获取优惠券信息
        Optional<MallMemberCoupon> optionalMallMemberCoupon = Optional.ofNullable(mallMemberCouponMapper.selectById(memberCouponId));
        MallMemberCoupon mallMemberCoupon = optionalMallMemberCoupon.orElse(null);

        if (mallMemberCoupon == null || mallMemberCoupon.getState() != 1) {
            return couponAmountMap;
        }
        Integer state = mallMemberCoupon.getState();
        if(1 != state){
            return couponAmountMap;
        }


        Long couponId = mallMemberCoupon.getCouponId();//优惠卷ID
        List<Long> goodsIdsAll = couponGoodsMapper.selectByCouponId(couponId);
        List<MallGoodsSku> skusAll = mallGoodsSkuMapper.selectSkuIdsByGoodsId(goodsIdsAll);//获取该优惠卷绑定的全部商品sku
        List<Long> skuIdsAll = skusAll.stream().map(MallGoodsSku::getId).collect(Collectors.toList());//获取该优惠卷绑定的全部商品skuIDS
        List<Long> skuIds = items.stream().map(AddOrderItemDto::getSkuId).collect(Collectors.toList());//订单中的全部skuIds
        Set<Long> skuIdsAll = skusAll.stream().map(MallGoodsSku::getId).collect(Collectors.toSet());//获取该优惠卷绑定的全部商品skuIDS
        Set<Long> skuIds = items.stream().map(AddOrderItemDto::getSkuId).collect(Collectors.toSet());//订单中的全部skuIds

        /**
         * 获取这张优惠卷生效的skuIds
         */
        Set<Long> intersection = skuIdsAll.stream()
                .filter(item -> skuIds.contains(item))
                .collect(Collectors.toSet());//获取两个集合的交集
        if(CollUtil.isEmpty(intersection)){
        // 获取交集
        Set<Long> intersection = skuIds.stream()
                .filter(skuIdsAll::contains)
                .collect(Collectors.toSet());

        if (intersection.isEmpty()) {
            return couponAmountMap;
        }
        HashMap<Long,BigDecimal> skuMap = new HashMap<>();//每个订单详情的ID和amount的map
        List<MallGoodsSku> skus = mallGoodsSkuMapper.selectByIds(new ArrayList<>(intersection));
        BigDecimal totalAmount = BigDecimal.ZERO;//订单中的总金额
        Map<Long, AddOrderItemDto> itemMap = new HashMap<>();// 预先将items转换为Map，以skuId作为键
        for (AddOrderItemDto addOrderItemDto : items) {
            itemMap.put(addOrderItemDto.getSkuId(), addOrderItemDto);
        }
        for(MallGoodsSku mallGoodsSku : skus){

        // 获取订单详情的ID和amount的map
        Map<Long, AddOrderItemDto> itemMap = items.stream()
                .collect(Collectors.toMap(AddOrderItemDto::getSkuId, item -> item));

        List<MallGoodsSku> skus = mallGoodsSkuMapper.selectList(
                new LambdaQueryWrapper<MallGoodsSku>()
                        .select(MallGoodsSku::getId, MallGoodsSku::getPresentPrice)
                        .in(MallGoodsSku::getId, intersection)
        );
        BigDecimal totalAmount = BigDecimal.ZERO;
        Map<Long, BigDecimal> skuMap = new HashMap<>();

        for (MallGoodsSku mallGoodsSku : skus) {
            Long id = mallGoodsSku.getId();
            BigDecimal presentPrice = mallGoodsSku.getPresentPrice();
            // 检查itemMap中是否存在该商品
            AddOrderItemDto addOrderItemDto = itemMap.get(id);
            if (addOrderItemDto != null) {
                BigDecimal skuAmount = presentPrice.multiply(BigDecimal.valueOf(addOrderItemDto.getCnt()));
                totalAmount = totalAmount.add(skuAmount);
                skuMap.put(id,skuAmount);
                skuMap.put(id, skuAmount);
            }
        }

        /**
         * 计算每个商品利用优惠卷打折的具体金额
         */
        MallGoodsCoupon mallGoodsCoupon = mallGoodsCouponMapper.selectById(mallMemberCoupon.getCouponId());
        BigDecimal costAmount = mallGoodsCoupon.getCostAmount();
        BigDecimal realAmount = mallGoodsCoupon.getRealAmount();
        if(totalAmount.compareTo(costAmount) < 0){
        // 计算每个商品利用优惠卷打折的具体金额
        Optional<MallGoodsCoupon> optionalMallGoodsCoupon = Optional.ofNullable(mallGoodsCouponMapper.selectById(mallMemberCoupon.getCouponId()));
        MallGoodsCoupon mallGoodsCoupon = optionalMallGoodsCoupon.orElse(null);
        if (mallGoodsCoupon == null) {
            return couponAmountMap;
        }
        HashMap<Long,BigDecimal> skuMapPercent = new HashMap<>();//每个订单详情的ID和amount的map

        BigDecimal costAmount = mallGoodsCoupon.getCostAmount();
        BigDecimal realAmount = mallGoodsCoupon.getRealAmount();

        if (totalAmount.compareTo(costAmount) < 0) {
            return couponAmountMap;
        }
        for (Map.Entry<Long,BigDecimal> entry : skuMap.entrySet()) {
            Long keySkuId = entry.getKey();
            BigDecimal valueSkuAmount = entry.getValue();
            BigDecimal divide = valueSkuAmount.divide(totalAmount, 4, BigDecimal.ROUND_DOWN);//每个商品占符合满减的总额的比例
            skuMapPercent.put(keySkuId,divide);
            BigDecimal divide = valueSkuAmount.divide(totalAmount, 4, RoundingMode.DOWN);//每个商品占符合满减的总额的比例
            Integer type = mallGoodsCoupon.getType();
            if(MallGoodsCoupon.TYPE_ONE == type){
                BigDecimal bigDecimal = realAmount.multiply(divide).setScale(0, BigDecimal.ROUND_DOWN);//每个SKU的减免金额(比例*减免金额)
                BigDecimal skuRealAmount = valueSkuAmount.subtract(bigDecimal.compareTo(BigDecimal.ZERO) > 0 ? bigDecimal : BigDecimal.ZERO);//实际支付金额
                couponAmountMap.put(keySkuId,skuRealAmount);
                BigDecimal bigDecimalOne = realAmount.multiply(divide).setScale(2, RoundingMode.DOWN);//每个SKU的减免金额(比例*减免金额)
                BigDecimal skuRealAmountOne = valueSkuAmount.subtract(bigDecimalOne.max(BigDecimal.ZERO));//实际支付金额
                couponAmountMap.put(keySkuId, skuRealAmountOne);
                continue;
            }
            if(MallGoodsCoupon.TYPE_TWO == type){
                BigDecimal divideTime = totalAmount.divide(costAmount, 0, BigDecimal.ROUND_DOWN);//累计减免次数
                BigDecimal divideTime = totalAmount.divide(costAmount, 0, RoundingMode.DOWN);//累计减免次数
                BigDecimal multiply = divideTime.multiply(realAmount);//实际减免金额
                BigDecimal bigDecimal = multiply.multiply(divide).setScale(0, BigDecimal.ROUND_DOWN);//每个SKU的减免金额(比例*实际减免金额)
                BigDecimal skuRealAmount = valueSkuAmount.subtract(bigDecimal.compareTo(BigDecimal.ZERO) > 0 ? bigDecimal : BigDecimal.ZERO);//实际支付金额
                couponAmountMap.put(keySkuId,skuRealAmount);
                BigDecimal bigDecimalTwo = multiply.multiply(divide).setScale(2, RoundingMode.DOWN);//每个SKU的减免金额(比例*实际减免金额)
                BigDecimal skuRealAmountTwo = valueSkuAmount.subtract(bigDecimalTwo.max(BigDecimal.ZERO));//实际支付金额
                couponAmountMap.put(keySkuId, skuRealAmountTwo);
                continue;
            }
        }
        return couponAmountMap;