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

//
class LessonStudentService extends CrudService {
  constructor(ctx) {
    super(ctx, 'lessonstudent');
    this.model = this.ctx.model.Business.LessonStudent;
    this.rscModel = this.ctx.model.Relation.RelationStudentCoach;
    this.lessonCoachModel = this.ctx.model.Business.LessonCoach;
    this.lessonModel = this.ctx.model.Business.Lesson;
    this.rcsModel = this.ctx.model.Relation.RelationCoachSchool;
    this.rssModel = this.ctx.model.Relation.RelationStudentSchool;
    this.billModel = this.ctx.model.Business.Bill;
    this.payOrderModel = this.ctx.model.Business.PayOrder;
    this.studentModel = this.ctx.model.User.Student;
    this.payService = this.ctx.service.wxpay;
    this.tran = new Transaction();
  }

  async checkCanUse({ school_id, student_id, lesson_id }) {
    const num = await this.model.count({ school_id, student_id, lesson_id, $or: [{ is_try: '0', is_pay: { $and: [{ $ne: '-3' }, { $ne: '-1' }] } }, { is_try: '1' }] });
    if (num > 0) throw new BusinessError(ErrorCode.DATA_EXISTED, '已存在有效的报名信息');
    return true;
  }

  async beforeCreate(body) {
    const { lesson_id, school_id, student_id } = body;
    // 检查是否已经有数据: 支付失败和已退款不算
    const data = await this.model.findOne({ lesson_id, school_id, student_id, $or: [{ is_try: '0', is_pay: { $nin: [ '-1', '-3' ] } }, { is_try: '1' }] });
    // 数据已存在
    if (data) throw new BusinessError(ErrorCode.DATA_EXISTED, '您已报名');
    // 数据不存在
    const { is_try } = body;
    // 检查是否使用试听名额
    if (is_try === '1') {
      const num = await this.model.count({ student_id, is_try: '1' });
      if (num > 0) throw new BusinessError(ErrorCode.SERVICE_FAULT, '您已使用过免费试听的机会');
    }
    return body;
  }

  async create(data) {
    // 检查是否能报名上课
    data = await this.beforeCreate(data);
    // 能报名上课,就直接创建数据
    try {
      // 创建数据
      const id = this.tran.insert('LessonStudent', data);
      const { school_id, student_id: payer_id, money, openid } = data;
      if (!openid) throw new BusinessError(ErrorCode.DATA_NOT_EXIST, '未找到用户的微信信息');
      const payData = {
        openid,
        school_id,
        payer_id,
        payer_role: 'Student',
        pay_for: 'LessonStudent',
        from_id: id,
        time: moment().format('YYYY-MM-DD HH:mm:ss'),
        order_no: this.ctx.service.business.payOrder.getOrderNo(),
        desc: '课程费',
        money,
      };
      // 计算付款单支付金额
      // 有余额且余额够,就直接扣余额;余额不足,就直接去支付
      const relation = await this.rssModel.findOne({ student_id: payer_id, school_id });
      if (!relation) throw new BusinessError(ErrorCode.DATA_NOT_EXIST, '未找到在校记录');
      const { money: surplus } = relation;
      let billId;
      if (this.ctx.minus(surplus, money) >= 0) {
        // 余额够,生成账单
        const billData = _.pick(payData, [ 'school_id', 'payer_role', 'payer_id', 'pay_for', 'from_id' ]);
        billData.type = '-2';
        billData.is_pay = '1';
        billData.time = moment().format('YYYY-MM-DD HH:mm:ss');
        billId = this.tran.insert('Bill', billData);
        // 减少余额
        const rs = this.ctx.minus(surplus, data.money);
        this.tran.update('RelationStudentSchool', relation._id, { money: rs });
        // 生成付款单数据,但是不需要支付
        payData.status = '1';
        payData.config = {
          useSurplus: true,
          bill: billId,
          money,
        };
      }
      const pay_id = this.tran.insert('PayOrder', payData);
      const result = { pay_id };
      // 如果生成账单id,则说明是全余额付的.修改账单的数据,将pay_id改了
      if (billId) this.tran.update('Bill', billId, { pay_id });
      else {
        // 需要微信支付签名(填充回调函数,回调函数处理)
        const wxSign = await this.payService.create({ ...payData, notice_url: this.app.config.payReturn });
        result.wxSign = wxSign;
      }
      await this.tran.run();
      return result;
    } catch (error) {
      await this.tran.rollback();
      throw Error(error);
    } finally {
      this.tran.clean();
    }
  }

  // 计算价格
  async toComputed({ lesson_id, student_id }) {
    // 通过课程id找到该课的所有教练
    const lesson = await this.lessonModel.findById(lesson_id);
    if (!lesson) throw new BusinessError(ErrorCode.DATA_NOT_EXIST, '未找到数据');
    const data = JSON.parse(JSON.stringify(lesson));
    const lessonMoney = _.get(data, 'money');
    const lessonType = _.get(data, 'type');
    if (!lessonMoney) throw new BusinessError(ErrorCode.DATA_INVALID, '课程设置错误,缺少教练费');
    // lesson中的money: 是学生应缴费用;
    // lessonStudent中的money:是学生应缴费用(公开课不计算,私教课需要查下有没有教师的优惠);
    // lessonCoach中的money: 是教师公开课每人应收的费用
    // 学生应缴计算方式: 公开课:lesson中的money; 私教课 lesson中的money - 和该教练的优惠 (可以没有)
    // 教练应收计算方式: 公开课: lessonCoach中设置的单价*人数; 私教课: (lesson的money - 对该学生的优惠) 之和
    if (lessonType === '0') {
      // 公开课
      data.real_money = lessonMoney;
    } else {
      // 找教练和学生的设置
      // 虽然用find,但实际上只有一个教练,但凡有2个,就应该不是私教课了
      const lessonCoachs = await this.lessonCoachModel.find({ lesson_id });
      if (lessonCoachs.length <= 0) return data;
      const coach_ids = lessonCoachs.map(i => i.coach_id);
      const rsc = await this.rscModel.findOne({ coach_id: coach_ids, student_id });
      if (rsc) {
        const discountType = _.get(rsc, 'config.discount_type'); // fixed;subtract;discount
        const number = _.get(rsc, 'config.number');
        if (discountType && number) {
          // 优惠目前设置3种: 固定金额; ${num}(num>1):减num元; x折; 打x折(money * (x/100))
          if (discountType === 'fixed') {
            // 固定金额
            data.real_money = number >= 0 ? number : 0;
          } else if (discountType === 'subtract') {
            data.real_money = lessonMoney - number >= 0 ? lessonMoney - number : 0;
          } else if (discountType === 'discount') {
            data.real_money = _.round(_.multiply(lessonMoney, _.divide(number, 10)), 2);
          }
          data.config = _.get(rsc, 'config');
        }
      }
    }

    return data;
  }

  // 退课,将钱退至余额
  async toRefund({ lesson_id, student_id }) {
    const payOrderService = this.ctx.service.business.payOrder;
    const payOrderModel = this.ctx.model.Business.PayOrder;
    const billModel = this.ctx.model.Business.Bill;
    const data = await this.model.findOne({ lesson_id, student_id });
    if (!data) throw new BusinessError(ErrorCode.DATA_NOT_EXIST, '未找到数据');
    const lesson = await this.lessonModel.findById(lesson_id);
    if (!lesson) throw new BusinessError(ErrorCode.DATA_NOT_EXIST, '未找到课程数据');
    if (!moment().isBefore(lesson.refund_hour)) throw new BusinessError(ErrorCode.DATA_INVALID, '已经超过退课时间,无法退课');
    if (data.is_pay === '-3') throw new BusinessError(ErrorCode.DATA_INVALID, '已经完成退课,无法再次退课');
    if (data.is_try === '1') {
      // 试课 修改退款状态, 而不需要退钱,同时也浪费了试课机会
      data.is_pay = '-3';
      await data.save();
      return;
    }
    // 交钱退课的
    if (data.pay_id) {
      // 正常交钱的课,将 pay_id 的status 修改为 -3, 同时触发修改这条数据,但是没有退款;
      await payOrderService.update({ _id: data.pay_id }, { status: '-3' });
      const payOrder = await payOrderModel.findById(data.pay_id);
      // 再生成账单记录
      const obj = _.pick(payOrder, [ 'school_id', 'payer_role', 'payer_id', 'pay_for', 'from_id' ]);
      obj.money = data.money;
      obj.type = '2';
      obj.is_pay = '1';
      obj.time = moment().format('YYYY-MM-DD HH:mm:ss');
      // 检查是否有从余额扣款部分
      if (_.get(payOrder, 'config,useSurplus')) {
        // 有余额扣款部分,查账单把钱加上
        const billId = _.get(payOrder, 'config,bill');
        const bill = await this.billModel.findById(billId);
        bill.is_pay = '-3';
        await bill.save();
      }
      await billModel.create(obj);
      // 再将钱返回给余额
      let relation;
      const { payer_role, payer_id, school_id } = payOrder;
      if (payer_role === 'Student') relation = await this.rssModel.findOne({ student_id: payer_id, school_id });
      else if (payer_role === 'Coach') relation = await this.rcsModel.findOne({ coach_id: payer_id, school_id });
      relation.money = _.get(relation, 'money', 0) + _.get(obj, 'money', 0);
      await relation.save();
      return;
    }
    // 从余额付款,退回余额
    const obj = {
      school_id: data.school_id,
      payer_id: student_id,
      payer_role: 'Student',
      pay_for: 'lessonStudent',
      from_id: data._id,
      type: '2',
      is_pay: '1',
      time: moment().format('YYYY-MM-DD HH:mm:ss'),
      money: data.money,
    };
    // 创建退回余额的账单
    await billModel.create(obj);
    const relation = await this.rssModel.findOne({ student_id, school_id: data.school_id });
    relation.money = _.get(relation, 'money', 0) + _.get(obj, 'money', 0);
    // 退回至账户
    await relation.save();
    data.is_pay = '-3';
    // 学员退课
    await data.save();
  }
}

module.exports = LessonStudentService;