class GetPeriod {
  constructor(year, month, day) {
    this.now = (year == undefined || month == undefined || day == undefined)? new Date(): new Date(year, month, day) 
    //console.log(this.now.getFullYear())
    this.nowYear = this.now.getFullYear(); //当前年 
    this.nowMonth = this.now.getMonth(); //当前月 
    this.nowDay = this.now.getDate(); //当前日 
    this.nowDayOfWeek = this.now.getDay() == 0? 7: this.now.getDay(); //今天是本周的第几天 
    //this.nowYear += (this.nowYear < 2000) ? 1900 : 0;
  }

  //获取当日零点的时间
  getZeroTime() {
    return new Date(this.nowYear, this.nowMonth, this.nowDay)
  }

  //格式化数字
  formatNumber(n) {
    n = n.toString()
    return n[1] ? n : '0' + n
  }
  //格式化日期
  formatDate(date) {
    let myyear = date.getFullYear();
    let mymonth = date.getMonth() + 1;
    let myweekday = date.getDate();
    return [myyear, mymonth, myweekday].map(this.formatNumber).join('-');
  }
  //格式化年月
  formatYearMonth(date) {
    let myyear = date.getFullYear();
    let mymonth = date.getMonth() + 1;
    return [myyear, mymonth].map(this.formatNumber).join('-');
  }
  //获取某月的天数
  getMonthDays(myMonth) {
    let monthStartDate = new Date(this.nowYear, myMonth, 1);
    let monthEndDate = new Date(this.nowYear, myMonth + 1, 1);
    let days = (monthEndDate - monthStartDate) / (1000 * 60 * 60 * 24);
    return days;
  }
  //获取本季度的开始月份
  getQuarterStartMonth() {
    let startMonth = 0;
    if (this.nowMonth < 3) {
      startMonth = 0;
    }
    if (2 < this.nowMonth && this.nowMonth < 6) {
      startMonth = 3;
    }
    if (5 < this.nowMonth && this.nowMonth < 9) {
      startMonth = 6;
    }
    if (this.nowMonth > 8) {
      startMonth = 9;
    }
    return startMonth;
  }
  //获取今天的日期
  getNowDate() {
    return this.formatDate(new Date(this.nowYear, this.nowMonth, this.nowDay));
  }

  //单独获取今天的年月
  getNowYearMonth() {
    return this.formatYearMonth(new Date(this.nowYear, this.nowMonth, this.nowDay));
  }

  //获取本周的开始日期
  getWeekStartformatDate() {
    return this.formatDate(new Date(this.nowYear, this.nowMonth, this.nowDay - this.nowDayOfWeek + 1));
  }

  //获取本周的开始日期
  getWeekStartDate() {
    const date = new Date(this.nowYear, this.nowMonth, this.nowDay - this.nowDayOfWeek + 1) 
    return date;
  }

  //获取本周的结束日期
  getWeekEndformatDate() {
    return this.formatDate(new Date(this.nowYear, this.nowMonth, this.nowDay + (6 - this.nowDayOfWeek + 1)));
  }

  //获取本周的结束日期
  getWeekEndDate() {
    const date = new Date(this.nowYear, this.nowMonth, this.nowDay + (6 - this.nowDayOfWeek + 1))
    return date;
  }
  //获取本月的开始日期
  getMonthStartDate() {
    return this.formatDate(new Date(this.nowYear, this.nowMonth, 1));
  }
  //获取本月的结束日期
  getMonthEndDate() {
    return this.formatDate(new Date(this.nowYear, this.nowMonth, this.getMonthDays(this.nowMonth)));
  }
  //获取本季度的开始日期
  getQuarterStartDate() {
    return this.formatDate(new Date(this.nowYear, this.getQuarterStartMonth(), 1));
  }
  //获取本季度的结束日期 
  getQuarterEndDate() {
    return this.formatDate(new Date(this.nowYear, this.getQuarterStartMonth() + 2, this.getMonthDays(this.getQuarterStartMonth() + 2)));
  }
  //获取本年的开始日期
  getYearStartDate() {
    return this.formatDate(new Date(this.nowYear, 0, 1));
  }
  //获取本年的结束日期
  getYearEndDate() {
    return this.formatDate(new Date(this.nowYear, 11, 31));
  }
  //获取时段方法
  getPeriod(obj) {
    let opts = obj || {}, time = null;
    opts = {
      periodType: opts.periodType || 'now',
      spaceType: opts.spaceType || '~'
    }
    function formatNumber(param1, param2) {
      return [param1, param2].join(opts.spaceType);
    }
    if (opts.periodType == 'week') {
      time = formatNumber(this.getWeekStartDate(), this.getWeekEndDate());
    } else if (opts.periodType == 'month') {
      time = formatNumber(this.getMonthStartDate(), this.getMonthEndDate());
    } else if (opts.periodType == 'quarter') {
      time = formatNumber(this.getQuarterStartDate(), this.getQuarterEndDate());
    } else if (opts.periodType == 'year') {
      time = formatNumber(this.getYearStartDate(), this.getYearEndDate());
    } else {
      time = formatNumber(this.getNowDate(), this.getNowDate());
    }
    return time;
  }
}
module.exports = GetPeriod;