'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 Transaction = require('mongoose-transactions');

//
class GoodsService extends CrudService {
  constructor(ctx) {
    super(ctx, 'goods');
    this.model = this.ctx.model.Shop.Goods;
    this.goodsSpecmodel = this.ctx.model.Shop.GoodsSpec;
    this.tran = new Transaction();
  }

  async beforeCreate(data) {
    // 为商品随机生成不重复的code
    if (!data.code) data.code = await this.makeCode();
    await this.checkCode(data.code);
    return data;
  }
  async beforeUpdate(filter, update) {
    const id = _.get(filter, 'id', _.get(filter, '_id'));
    const code = _.get(update, 'code');
    await this.checkCode(code, id);
    return { filter, update };
  }

  async query(filter, { skip = 0, limit, sort, desc, projection } = {}) {
    // 处理排序
    let condition = _.cloneDeep(filter);
    condition = this.dealFilter(condition);
    const pipeline = this.getQueryPipeline(condition);
    if (parseInt(skip)) pipeline.push({ $skip: parseInt(skip) });
    if (parseInt(limit)) pipeline.push({ $limit: parseInt(limit) });
    const rs = await this.model.aggregate(pipeline);
    return rs;
  }

  async count(filter) {
    let condition = _.cloneDeep(filter);
    condition = this.dealFilter(condition);
    const pipeline = this.getQueryPipeline(condition);
    pipeline.push({ $count: 'total' });
    const total = await this.model.aggregate(pipeline);
    return _.get(_.head(total), 'total', 0);
  }

  getQueryPipeline(filter) {
    const pipeline = [];
    const { tags, spec_name, ...others } = filter;
    const $match = { ...others };
    if (tags) {
      $match.tags = { $elemMatch: { $elemMatch: { $eq: tags } } };
    }
    pipeline.push({ $match });
    if (spec_name) {
      const $addFields = { goods_id: { $toString: '$_id' } };
      const $lookup = {
        from: 'goodsSpec',
        localField: 'goods_id',
        foreignField: 'goods',
        pipeline: [{ $match: { name: new RegExp(spec_name) } }],
        as: 'sp',
      };
      const $unwind = '$sp';
      const $project = { sp: 0, goods_id: 0 };
      pipeline.push({ $addFields }, { $lookup }, { $unwind }, { $project });

    }
    pipeline.push({ $sort: { sort: -1 } });
    return pipeline;
  }

  /**
   * 检查商品编码是否唯一,若传id,则将该id排除在外
   * @param {String} code 商品唯一编码
   * @param {String} id 商品id
   */
  async checkCode(code, id) {
    if (!code) return;
    const query = { code };
    if (id) query.id = { $ne: id };
    const num = await this.model.find(query);
    if (num > 0) throw new BusinessError(ErrorCode.DATA_EXISTED, '该编码已被其他商品使用');
    return;
  }

  // 生成商品编码
  async makeCode() {
    let code = '';
    let is_has = false;
    do {
      code = Math.random().toString(36).substring(3, 11);
      const num = await this.model.find({ code });
      is_has = num > 0;
    } while (is_has);
    return code;
  }

  async toDuplicate({ id }) {
    const data = await this.model.findById(id);
    if (!data) throw new BusinessError(ErrorCode.DATA_NOT_EXIST, '未找到数据');
    let specList = await this.goodsSpecmodel.find({ goods: id });
    if (specList.length > 0) specList = JSON.parse(JSON.stringify(specList));
    const nd = JSON.parse(JSON.stringify(data));
    nd.name = `${nd.name}-复制-${new Date().getTime()}`;
    delete nd.id;
    delete nd._id;
    delete nd.meta;
    delete nd.__v;
    try {
      const id = this.tran.insert('Goods', nd);
      specList = specList.map(i => {
        delete i.id;
        delete i._id;
        delete i.meta;
        delete i.__v;
        i.goods = id;
        return i;
      });
      for (const i of specList) this.tran.insert('GoodsSpec', i);
      await this.tran.run();
    } catch (error) {
      console.log(error);
      await this.tran.rollback();
    } finally {
      this.tran.clean();
    }
  }
}

module.exports = GoodsService;