server/app/service/trade/cart.js

'use strict';
const { CrudService } = require('naf-framework-mongoose-free/lib/service');
const { BusinessError, ErrorCode } = require('naf-core').Error;
const _ = require('lodash');
const assert = require('assert');
const { ObjectId } = require('mongoose').Types;
//
class CartService extends CrudService {
  constructor(ctx) {
    super(ctx, 'cart');
    this.model = this.ctx.model.Trade.Cart;
    this.goodsSpecModel = this.ctx.model.Shop.GoodsSpec;
    this.platformActModel = this.ctx.model.System.PlatformAct;
    this.gjaModel = this.ctx.model.Shop.GoodsJoinAct;
    this.setModel = this.ctx.model.Shop.GoodsSet;
    this.shopModel = this.ctx.model.Shop.Shop;
    this.goodsModel = this.ctx.model.Shop.Goods;
  }

  /**
   * 返回购物车需要的数据格式
   ** 添加促销部分:
   ** 买赠,特价,加价购: 需要查询每个商品是否参与了这三项活动,需要给出对应数据
   ** 满减/折:不需要在购物车出现
   ** 套装:最后下单时组合,购物车中不需要额外修改
   * @param {Object} query 查询条件
   * @param query.customer 顾客id
   * @return {Array}
   */
  async selfCart({ customer }) {
    assert(customer, '缺少顾客信息');
    let data = await this.model.find({ customer });
    if (data.length > 0) {
      data = JSON.parse(JSON.stringify(data));
      data = data.map(i => ({ ...i, cart_id: i._id }));
    }
    data = await this.getCartGoodsAct(data);
    const actList = await this.ctx.service.trade.order.getActList(data);
    const pageData = await this.ctx.service.trade.order.getPageData(data, actList);
    return pageData;
  }
  /**
   * 实时获取购物车内的商品参与的活动
   * @param {Array} data 购物车商品
   */
  async getCartGoodsAct(data) {
    data = data.map(i => ({ ...i, act: [] }));
    // 实时匹配活动问题
    const platformActList = await this.platformActModel.find({ is_use: '0' });
    const platform_act = platformActList.map(i => ObjectId(i._id).toString());
    for (const cart of data) {
      const { goodsSpec: spec_id, goods: goods_id, act = [], is_set = '1', set_id } = cart;
      if (is_set === '1' || !set_id) {
        // 非套装处理, 套装不参与其他活动
        const gjaList = await this.gjaModel.find({ platform_act, 'goods._id': ObjectId(goods_id).toString(), 'spec._id': ObjectId(spec_id).toString() });
        for (const gja of gjaList) {
          const { platform_act_type: type, platform_act } = gja;
          // 加价购需要额外判断是否是基础商品
          if (type === '4') {
            const goods_type = _.get(gja, 'config.goods_type');
            if (goods_type === 'basic') act.push(platform_act);
          } else act.push(platform_act);
        }
        cart.act = _.uniq(act);
      }
    }
    return data;
  }

  /**
   ** 创建购物车信息,若找到该店的该商品规格.进行库存校验
   ** 数量进行合并;
   ** 反之创建
   ** 添加促销活动部分:
   ** 买赠,特价,加价购: 不需要在创建时处理,而是在查询时实时处理,显示相关信息
   ** 满减/折:不需要在购物车出现
   ** 套装:只有套装需要记录在购物车中,以同一商品形式出现
   * @param {Object} body 请求参数
   * @param body.num 数量
   */
  async create({ num, ...body }) {
    const { customer, shop, goods, goodsSpec, is_set = '1', set_id } = body;
    assert(customer, '缺少顾客信息');
    if (is_set === '1') {
      assert(shop, '缺少店铺信息');
      assert(goods, '缺少商品信息');
      assert(goodsSpec, '缺少商品规格信息');
    } else assert(set_id, '缺少套装id');
    if (is_set === '1') {
      // 非套装 添加购物车
      const query = _.pick(body, [ 'customer', 'shop', 'goods', 'goodsSpec' ]);
      const data = await this.model.findOne(query);
      if (data) {
        const buyNum = this.ctx.plus(data.num, num);
        const { enough, msg } = await this.checkGoodsNum({ goodsSpecId: goodsSpec, num: buyNum });
        if (!enough) throw new BusinessError(ErrorCode.SERVICE_FAULT, msg);
        data.num = buyNum;
        await data.save();
      } else {
        const { enough, msg } = await this.checkGoodsNum({ goodsSpecId: goodsSpec, num });
        if (!enough) throw new BusinessError(ErrorCode.SERVICE_FAULT, msg);
        await this.model.create({ num, ...body });
      }
    } else {
      // 套装添加购物车
      const query = _.pick(body, [ 'customer', 'set_id' ]);
      const data = await this.model.findOne(query);
      if (data) {
        // 计算套装购买数量
        const buyNum = this.ctx.plus(data.num, num);
        const { enough, msg } = await this.checkSetGoodsNum(data, buyNum);
        if (!enough) throw new BusinessError(ErrorCode.SERVICE_FAULT, msg);
        data.num = buyNum;
        await data.save();
      } else {
        const { enough, msg, shop } = await this.checkSetGoodsNum(body, num);
        if (!enough) throw new BusinessError(ErrorCode.SERVICE_FAULT, msg);
        await this.model.create({ shop, num, ...body });
      }
    }
  }

  /**
   * 检查套装购物车库存是否足够
   * @param {Object} data 套装的购物车数据
   * @param {Number} buyNum 套装购买数量
   */
  async checkSetGoodsNum(data, buyNum) {
    const { set_id } = data;
    const setData = await this.setModel.findById(set_id).lean();
    const { shop } = setData;
    const shopData = await this.shopModel.findById(shop);
    const shopRes = this.ctx.service.util.trade.checkShop(shopData);
    if (shopRes.result !== true) throw new BusinessError(ErrorCode.DATA_INVALID, shopRes.msg);
    const { set } = setData;
    const stockList = [];
    for (const sd of set) {
      const { goods, spec, set_num } = sd;
      const goodsData = await this.goodsModel.findById(goods);
      const goodsRes = this.ctx.service.util.trade.checkGoods(goodsData);
      if (goodsRes.result !== true) throw new BusinessError(ErrorCode.DATA_INVALID, goodsRes.msg);
      const goodsSpecData = await this.goodsSpecModel.findById(spec);
      const setGoodsNum = this.ctx.multiply(buyNum, set_num);
      const gsRes = this.ctx.service.util.trade.checkGoodsSpec(goodsSpecData, setGoodsNum, '0');
      if (gsRes.result !== true) throw new BusinessError(ErrorCode.DATA_INVALID, gsRes.msg);
      const { num: gsnum = 0 } = goodsSpecData;
      // 应该用 库存/每套的件数 向下取整作为库存量
      const stock_num = _.floor(this.ctx.divide(gsnum, set_num));
      stockList.push(stock_num);
    }
    const total = _.min(stockList);
    return { enough: true, total, shop };
  }

  /**
   * 检查商品规格的库存
   * @param {String} goodsSpecId 商品规格id
   * @param {String} cartId 购物车id
   * @param {Number} num 需要的库存数量
   * @param {Boolean} update 修改购物车
   * @param {String} set_id 套装id
   * @return {Boolean} true:库存满足购物车条件;false:库存不满足条件
   */
  async checkGoodsNum({ cartId, goodsSpecId, num, set_id }, update = true) {
    if (set_id) {
      // 套装查询库存
      const cartData = await this.model.findById(cartId);
      const res = await this.checkSetGoodsNum(cartData, num);
      if (update && cartId) {
        await this.model.updateOne({ _id: cartId }, { num });
      }
      return res;
    }
    const { populate } = this.ctx.service.shop.goodsSpec.getRefMods();
    const goodsSpec = await this.goodsSpecModel.findById(goodsSpecId).populate(populate);
    if (!goodsSpec) throw new BusinessError(ErrorCode.DATA_NOT_EXIST, '未找到商品的规格数据');
    const goods = _.get(goodsSpec, 'goods');
    const shop = _.get(goods, 'shop');
    const shopRes = this.ctx.service.util.trade.checkShop(shop);
    if (shopRes.result !== true) throw new BusinessError(ErrorCode.DATA_INVALID, shopRes.msg);
    const goodsRes = this.ctx.service.util.trade.checkGoods(goods);
    if (goodsRes.result !== true) throw new BusinessError(ErrorCode.DATA_INVALID, goodsRes.msg);
    const gsRes = this.ctx.service.util.trade.checkGoodsSpec(goodsSpec, num);
    const { num: gsnum = 0 } = goodsSpec;
    if (gsRes.result !== true) {
      return { enough: false, total: gsnum, msg: gsRes.msg };
    }
    if (update && cartId) {
      await this.model.updateOne({ _id: cartId }, { num });
    }
    return { enough: true, total: gsnum };
  }
}

module.exports = CartService;