package com.ylx.giftCard.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.collection.CollectionUtil;
import cn.hutool.core.util.ObjectUtil;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.conditions.update.LambdaUpdateWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.ylx.common.core.domain.model.WxLoginUser;
import com.ylx.common.exception.ServiceException;
import com.ylx.common.utils.SecurityUtils;
import com.ylx.common.weixinPay.service.WxPayV3Service;
import com.ylx.giftCard.domain.GiftCard;
import com.ylx.giftCard.domain.GiftCardOrder;
import com.ylx.giftCard.domain.dto.GiftCardPurchaseDTO;
import com.ylx.giftCard.domain.vo.GiftCardDetailVO;
import com.ylx.giftCard.domain.vo.GiftCardVO;
import com.ylx.giftCard.mapper.GiftCardMapper;
import com.ylx.giftCard.service.IGiftCardOrderService;
import com.ylx.giftCard.service.IGiftCardService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

@Slf4j
@Service
public class GiftCardServiceImpl extends ServiceImpl<GiftCardMapper, GiftCard> implements IGiftCardService {

    @Resource
    private IGiftCardOrderService giftCardOrderService;
    @Resource
    private WxPayV3Service wxPayV3Service;

    private static final int NOT_DELETE = 0;
    private static final int PUBLISHED = 1;

    @Override
    public Page<GiftCardVO> getGiftCardPage(Page<GiftCard> page) {

        LambdaQueryWrapper<GiftCard> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(GiftCard::getIsDelete, NOT_DELETE);
        wrapper.eq(GiftCard::getIsPublished, PUBLISHED);
        wrapper.orderByDesc(GiftCard::getCreateTime);

        Page<GiftCard> giftCardPage = this.baseMapper.selectPage(page, wrapper);
        Page<GiftCardVO> pageData = new Page<>(
                giftCardPage.getCurrent(),
                giftCardPage.getSize(),
                giftCardPage.getTotal()
        );

        if (CollectionUtil.isNotEmpty(giftCardPage.getRecords())) {
            List<GiftCardVO> voList = giftCardPage.getRecords().stream()
                    .map(GiftCardVO::new)
                    .collect(Collectors.toList());
            pageData.setRecords(voList);
        }

        return pageData;
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public Map<String, Object> purchaseGiftCard(GiftCardPurchaseDTO dto) {

        // 1. 获取当前用户
        WxLoginUser wxLoginUser = SecurityUtils.getWxLoginUser();
        if (ObjectUtil.isNull(wxLoginUser)) {
            log.warn("用户未登录，无法创建订单");
            throw new ServiceException("用户未登录");
        }

        Long id = dto.getId();
        Integer quantity = dto.getQuantity();
        String merchantId = dto.getMerchantId();

        // 2. 查询并校验购物卡
        GiftCard card = this.getById(id);
        validateGiftCard(card, quantity);

        // 3. 乐观锁扣减库存（增加状态校验，防止无效更新）
        int rowsAffected = deductStockOptimisticLock(card.getId(), dto.getQuantity());
        if (rowsAffected <= 0) {
            log.warn("购买失败，库存不足或商品不存在，购物卡ID: {}", id);
            throw new ServiceException("库存不足或商品状态异常");
        }

        log.info("购买成功，购物卡ID: {}, 数量: {}", id, quantity);

        // 4. 创建订单
        GiftCardOrder order = this.giftCardOrderService.buildOrder(card, quantity, merchantId, wxLoginUser);

        //  5. 调用微信支付
        return createWxPayOrder(order, wxLoginUser);
    }

    @Override
    public GiftCardDetailVO getGiftCardDetail(Long id) {

        LambdaQueryWrapper<GiftCard> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(GiftCard::getId, id)
                .eq(GiftCard::getIsDelete, NOT_DELETE)
                .eq(GiftCard::getIsPublished, PUBLISHED);

        GiftCard card = this.getOne(wrapper);
        if (ObjectUtil.isNull(card)) {
            return null;
        }

        GiftCardDetailVO vo = new GiftCardDetailVO();
        BeanUtil.copyProperties(card, vo);
        return vo;
    }

    /**
     * 校验购物卡有效性
     */
    private void validateGiftCard(GiftCard card, Integer quantity) {
        if (ObjectUtil.isNull(card)) {
            throw new ServiceException("商品不存在");
        }
        if (card.getIsDelete() != NOT_DELETE) {
            log.warn("购买失败，购物卡已删除，ID: {}", card.getId());
            throw new ServiceException("购物卡已删除");
        }
        if (card.getIsPublished() != PUBLISHED) {
            log.warn("购买失败，购物卡未上架，ID: {}", card.getId());
            throw new ServiceException("购物卡未上架");
        }
        if (card.getStock() < quantity) {
            log.warn("购买失败，库存不足，ID: {}，库存: {}，需求数量: {}", card.getId(), card.getStock(), quantity);
            throw new ServiceException("库存不足");
        }

    }

    /**
     * 乐观锁扣减库存（增加状态条件，确保只更新有效记录）
     */
    private int deductStockOptimisticLock(Long cardId, Integer quantity) {
        LambdaUpdateWrapper<GiftCard> wrapper = new LambdaUpdateWrapper<>();
        wrapper.eq(GiftCard::getId, cardId)
                .eq(GiftCard::getIsDelete, NOT_DELETE)
                .eq(GiftCard::getIsPublished, PUBLISHED)
                .ge(GiftCard::getStock, quantity) // 库存充足时才更新
                .setSql("stock = stock - " + quantity + ", sales = sales + " + quantity);
        return baseMapper.update(null, wrapper);
    }

    /**
     * 补偿回滚库存
     */
    private void recoverStock(Long cardId, Integer num) {
        GiftCard updateEntity = new GiftCard();
        LambdaUpdateWrapper<GiftCard> updateWrapper = new LambdaUpdateWrapper<>();
        updateWrapper.eq(GiftCard::getId, cardId)
                .eq(GiftCard::getIsDelete, NOT_DELETE);
        updateWrapper.setSql("stock = stock + #{num}, sales = sales - #{num}");
        // 数据放到实体里
        updateEntity.setStock(num);
        baseMapper.update(updateEntity, updateWrapper);
    }

    /**
     * 创建微信支付订单（事务外执行，减少事务时长）
     */
    private Map<String, Object> createWxPayOrder(GiftCardOrder order, WxLoginUser wxLoginUser) {
        try {
            return wxPayV3Service.createV3JsapiOrder(
                    order.getOrderNo(),
                    order.getPayAmount(),
                    "购物卡购买",
                    wxLoginUser.getCOpenid()
            );
        } catch (Exception e) {
            log.error("微信支付下单失败，订单号: {}", order.getOrderNo(), e);
            // 支付失败：恢复库存、修改订单为取消
            recoverStock(order.getGiftCardId(), order.getPurchaseQuantity());
            this.giftCardOrderService.cancelOrder(order.getId());
            throw new ServiceException("支付服务异常，请稍后重试");
        }
    }

}