/**
 * 农历转换工具
 * 公历转农历
 */

const calendar = {
  /**
   * 农历1900-2100的润大小信息表
   * @Array Of Property
   * @return Hex
   */
  lunarInfo: [0x04bd8, 0x04ae0, 0x0a570, 0x054d5, 0x0d260, 0x0d950, 0x16554, 0x056a0, 0x09ad0, 0x055d2, // 1900-1909
    0x04ae0, 0x0a5b6, 0x0a4d0, 0x0d250, 0x1d255, 0x0b540, 0x0d6a0, 0x0ada2, 0x095b0, 0x14977, // 1910-1919
    0x04970, 0x0a4b0, 0x0b4b5, 0x06a50, 0x06d40, 0x1ab54, 0x02b60, 0x09570, 0x052f2, 0x04970, // 1920-1929
    0x06566, 0x0d4a0, 0x0ea50, 0x06e95, 0x05ad0, 0x02b60, 0x186e3, 0x092e0, 0x1c8d7, 0x0c950, // 1930-1939
    0x0d4a0, 0x1d8a6, 0x0b550, 0x056a0, 0x1a5b4, 0x025d0, 0x092d0, 0x0d2b2, 0x0a950, 0x0b557, // 1940-1949
    0x06ca0, 0x0b550, 0x15355, 0x04da0, 0x0a5b0, 0x14573, 0x052b0, 0x0a9a8, 0x0e950, 0x06aa0, // 1950-1959
    0x0aea6, 0x0ab50, 0x04b60, 0x0aae4, 0x0a570, 0x05260, 0x0f263, 0x0d950, 0x05b57, 0x056a0, // 1960-1969
    0x096d0, 0x04dd5, 0x04ad0, 0x0a4d0, 0x0d4d4, 0x0d250, 0x0d558, 0x0b540, 0x0b6a0, 0x195a6, // 1970-1979
    0x095b0, 0x049b0, 0x0a974, 0x0a4b0, 0x0b27a, 0x06a50, 0x06d40, 0x0af46, 0x0ab60, 0x09570, // 1980-1989
    0x04af5, 0x04970, 0x064b0, 0x074a3, 0x0ea50, 0x06b58, 0x05ac0, 0x0ab60, 0x096d5, 0x092e0, // 1990-1999
    0x0c960, 0x0d954, 0x0d4a0, 0x0da50, 0x07552, 0x056a0, 0x0abb7, 0x025d0, 0x092d0, 0x0cab5, // 2000-2009
    0x0a950, 0x0b4a0, 0x0baa4, 0x0ad50, 0x055d9, 0x04ba0, 0x0a5b0, 0x15176, 0x052b0, 0x0a930, // 2010-2019
    0x07954, 0x06aa0, 0x0ad50, 0x05b52, 0x04b60, 0x0a6e6, 0x0a4e0, 0x0d260, 0x0ea65, 0x0d530, // 2020-2029
    0x05aa0, 0x076a3, 0x096d0, 0x04afb, 0x04ad0, 0x0a4d0, 0x1d0b6, 0x0d250, 0x0d520, 0x0dd45, // 2030-2039
    0x0b5a0, 0x056d0, 0x055b2, 0x049b0, 0x0a577, 0x0a4b0, 0x0aa50, 0x1b255, 0x06d20, 0x0ada0, // 2040-2049
    0x14b63, 0x09370, 0x049f8, 0x04970, 0x064b0, 0x168a6, 0x0ea50, 0x06b20, 0x1a6c4, 0x0aae0, // 2050-2059
    0x0a2e0, 0x0d2e3, 0x0c960, 0x0d557, 0x0d4a0, 0x0da50, 0x05d55, 0x056a0, 0x0a6d0, 0x055d4, // 2060-2069
    0x052d0, 0x0a9b8, 0x0a950, 0x0b4a0, 0x0b6a6, 0x0ad50, 0x055a0, 0x0aba4, 0x0a5b0, 0x052b0, // 2070-2079
    0x0b273, 0x06930, 0x07337, 0x06aa0, 0x0ad50, 0x14b55, 0x04b60, 0x0a570, 0x054e4, 0x0d160, // 2080-2089
    0x0e968, 0x0d520, 0x0daa0, 0x16aa6, 0x056d0, 0x04ae0, 0x0a9d4, 0x0a2d0, 0x0d150, 0x0f252, // 2090-2099
    0x0d520], // 2100

  /**
   * 天干地支之天干速查表
   */
  Gan: ['甲', '乙', '丙', '丁', '戊', '己', '庚', '辛', '壬', '癸'],

  /**
   * 天干地支之地支速查表
   */
  Zhi: ['子', '丑', '寅', '卯', '辰', '巳', '午', '未', '申', '酉', '戌', '亥'],

  /**
   * 生肖速查表
   */
  Animals: ['鼠', '牛', '虎', '兔', '龙', '蛇', '马', '羊', '猴', '鸡', '狗', '猪'],

  /**
   * 农历日期名称
   */
  nStr1: ['日', '一', '二', '三', '四', '五', '六', '七', '八', '九', '十'],
  nStr2: ['初', '十', '廿', '卅'],

  /**
   * 农历月份名称
   */
  monthName: ['正月', '二月', '三月', '四月', '五月', '六月', '七月', '八月', '九月', '十月', '冬月', '腊月'],

  /**
   * 返回农历y年的总天数
   */
  lYearDays: function (y) {
    let i
    let sum = 348
    for (i = 0x8000; i > 0x8; i >>= 1) sum += (this.lunarInfo[y - 1900] & i) ? 1 : 0
    return (sum + this.leapDays(y))
  },

  /**
   * 返回农历y年闰月的天数
   */
  leapDays: function (y) {
    if (this.leapMonth(y)) return ((this.lunarInfo[y - 1900] & 0x10000) ? 30 : 29)
    else return (0)
  },

  /**
   * 返回农历y年闰哪个月 1-12 , 没闰返回 0
   */
  leapMonth: function (y) {
    return (this.lunarInfo[y - 1900] & 0xf)
  },

  /**
   * 返回农历y年m月的总天数
   */
  monthDays: function (y, m) {
    return ((this.lunarInfo[y - 1900] & (0x10000 >> m)) ? 30 : 29)
  },

  /**
   * 传入offset偏移量返回干支
   */
  cyclical: function (num) {
    return (this.Gan[num % 10] + this.Zhi[num % 12])
  },

  /**
   * 传入农历数字月份返回汉语通俗表示法
   */
  toChinaMonth: function (m) {
    if (m > 12 || m < 1) return -1
    return this.monthName[m - 1]
  },

  /**
   * 传入农历日期数字返回汉字表示法
   */
  toChinaDay: function (d) {
    let s
    switch (d) {
      case 10:
        s = '初十'
        break
      case 20:
        s = '二十'
        break
      case 30:
        s = '三十'
        break
      default:
        s = this.nStr2[Math.floor(d / 10)]
        s += this.nStr1[d % 10]
    }
    return (s)
  },

  /**
   * 公历转农历
   */
  solar2lunar: function (y, m, d) {
    // 参数区间1900.1.31~2100.12.31
    if (y < 1900 || y > 2100) return { IDayCn: '', IMonthCn: '' }
    if (y === 1900 && m === 1 && d < 31) return { IDayCn: '', IMonthCn: '' }

    let objDate
    if (typeof y === 'object' && y instanceof Date) {
      objDate = y
    } else {
      objDate = new Date(y, parseInt(m) - 1, d)
    }

    let i
    let leap = 0
    let temp = 0
    const baseDate = new Date(1900, 0, 31)
    let offset = (objDate - baseDate) / 86400000

    let dayCyl = offset + 40
    let monCyl = 14

    let year, yearCyl, month, day, isLeap = false

    for (i = 1900; i < 2101 && offset > 0; i++) {
      temp = this.lYearDays(i)
      offset -= temp
      monCyl += 12
    }

    if (offset < 0) {
      offset += temp
      i--
      monCyl -= 12
    }

    year = i
    yearCyl = i - 1864

    leap = this.leapMonth(i)
    isLeap = false

    for (i = 1; i < 13 && offset > 0; i++) {
      if (leap > 0 && i === (leap + 1) && isLeap === false) {
        --i
        isLeap = true
        temp = this.leapDays(year)
      } else {
        temp = this.monthDays(year, i)
      }

      if (isLeap === true && i === (leap + 1)) isLeap = false

      offset -= temp
      if (isLeap === false) monCyl++
    }

    if (offset === 0 && leap > 0 && i === leap + 1) {
      if (isLeap) {
        isLeap = false
      } else {
        isLeap = true
        --i
        --monCyl
      }
    }

    if (offset < 0) {
      offset += temp
      --i
      --monCyl
    }

    month = i
    day = Math.round(offset + 1)

    const gzY = this.cyclical(year - 1900 + 36)
    const animal = this.Animals[(year - 4) % 12]

    return {
      lYear: year,
      lMonth: month,
      lDay: day,
      Animal: animal,
      IMonthCn: (isLeap ? '闰' : '') + this.toChinaMonth(month),
      IDayCn: this.toChinaDay(day),
      cYear: y,
      cMonth: m,
      cDay: d,
      gzYear: gzY,
      isLeap: isLeap,
      nWeek: objDate.getDay(),
      ncWeek: '星期' + this.nStr1[objDate.getDay()],
      isTerm: false,
      Term: null
    }
  }
}

export default calendar