mh_server/model/mall_cart.go

package model

import "github.com/codinl/go-logger"

// gen:qs
//
//go:generate goqueryset -in mall_cart.go
type MallCart struct {
	Model

	Uid     uint64 `json:"uid" gorm:"index"`
	GoodsId uint32 `json:"goods_id"` // 商品id
	Count   uint32 `json:"count"`    // 数量

	GoodsInfo Goods `json:"goods_info" gorm:"-"`
}

type MallCartAddReq struct {
	GoodsId uint32 `json:"goods_id"`
	AddType uint32 `json:"add_type"` // 1-加 2-减
}

type MallCartListReq struct {
	PageNum  int `json:"page_num"`
	PageSize int `json:"page_size"`
}

type MallCartListResp struct {
	List    []MallCart `json:"list"`
	Total   int        `json:"total"`
	PageNum int        `json:"page_num"`
}

type MallCartDel struct {
	MallCartIds []uint32 `json:"mall_cart_ids"`
}

// MallCartList 封装商城购物车列表查询
func MallCartList(uid uint32, pageNum, pageSize int) (*MallCartListResp, error) {
	resp := &MallCartListResp{
		PageNum: pageNum,
		List:    []MallCart{}, // 初始化为空列表，避免返回 nil
	}

	// 默认分页参数
	page := pageNum - 1
	if page < 0 {
		page = 0
	}
	if pageSize <= 0 {
		pageSize = 10
	}

	qs := NewMallCartQuerySet(DB).UidEq(uint64(uid))

	// 获取总数
	count, err := qs.Count()
	if err != nil {
		logger.Error("err:", err)
		return resp, err
	}
	if count == 0 {
		resp.Total = 0
		return resp, nil
	}

	// 计算总页数
	resp.Total = (count + pageSize - 1) / pageSize // 向上取整

	// 分页查询
	var mallCarts []MallCart
	err = qs.OrderDescByID().Offset(page * pageSize).Limit(pageSize).All(&mallCarts)
	if err != nil && err != RecordNotFound {
		logger.Error("err:", err)
		return resp, err
	}
	if len(mallCarts) == 0 {
		return resp, nil
	}

	// 收集商品 ID
	ids := make([]uint32, 0, len(mallCarts))
	for _, v := range mallCarts {
		ids = append(ids, v.GoodsId)
	}

	// 查询商品信息（避免 ids 为空）
	if len(ids) > 0 {
		var goodsList []Goods
		err = NewGoodsQuerySet(DB).GoodsIdIn(ids...).All(&goodsList)
		if err != nil && err != RecordNotFound {
			logger.Error("err:", err)
			return resp, err
		}

		// 建立 map
		goodsMap := make(map[uint32]Goods, len(goodsList))
		for _, g := range goodsList {
			goodsMap[g.GoodsId] = g
		}

		// 绑定商品信息
		for i := range mallCarts {
			if g, ok := goodsMap[mallCarts[i].GoodsId]; ok {
				mallCarts[i].GoodsInfo = g
			}
		}
	}

	resp.List = mallCarts
	return resp, nil
}