server/app/service/util/orderDetail.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');

//
class OrderDetailService extends CrudService {
  constructor(ctx) {
    super(ctx, 'orderdetail');
  }
  /**
   * 计算订单详情实际支付金额
   * @param {Object} data 订单详情数据
   * @return {Number} 实际支付金额
   */
  async computedRealPay(data) {
    const { goods = [], total_detail = {} } = data;
    let total = goods.reduce((p, n) => {
      const price = this.ctx.plus(n.sell_money, n.freight);
      const goodsTotal = this.ctx.multiply(price, n.buy_num);
      return this.ctx.plus(p, goodsTotal);
    }, 0);
    let dmt = 0;
    const discount_detail = _.get(total_detail, 'discount_detail', {});
    for (const uc_id in discount_detail) {
      const detail = _.get(discount_detail, uc_id, {});
      const values = Object.values(detail);
      const dm = values.reduce((p, n) => this.ctx.plus(p, n), 0);
      dmt = this.ctx.plus(dmt, dm);

    }
    total = this.ctx.minus(total, dmt);
    if (total <= 0) total = 0;
    return total;
  }
}

module.exports = OrderDetailService;