let strftime = require("strftime")
function getDateList(day){
    let n                     = 3
    let deliveryCandidateDays = []

    while(deliveryCandidateDays.length < 8) {
        let allDays = []
        let m = 1

        while(m <= n - 2){
            allDays.push(new Date(day.getFullYear(), day.getMonth(), day.getDate() + m))
            m += 1
            // console.log("allDays", allDays)
        }

        let businessDays = allDays.filter(function(element){
            let JapaneseHolidays        = require('japanese-holidays')
            let holiday                 = JapaneseHolidays.isHoliday(element)
            let numberOfTheDayOfTheWeek = strftime("%w", element)

            return (!(holiday || numberOfTheDayOfTheWeek == 0 || numberOfTheDayOfTheWeek == 6))
        })

        // console.log("businessDays", businessDays)
        // console.log("deliveryCandidateDays", deliveryCandidateDays)
        if(businessDays.length > 0){
            let avalabilitishDay = new Date(day.getFullYear(), day.getMonth(), day.getDate() + n)
            // console.log("avalabilitishDay", avalabilitishDay)
            deliveryCandidateDays.push({
                dateJp : strftime("%m月%d日" , avalabilitishDay) ,
                dateEn : strftime("%Y-%m-%d" , avalabilitishDay) ,
            })
        }
        n += 1
    }
    return deliveryCandidateDays
}

let s = 0;
function assert_equal(arg1 , arg2){
    s++;
    if(arg1.length != arg2.length){
        throw("not equals")
    }

    for(let i = 0 ; i < arg1.length ; i++){
        if(arg1[i]["dateJp"] != arg2[i]["dateJp"]){
            console.log(arg1[i]["dateJp"])
            console.log(arg2[i]["dateJp"])
            throw("not equals " + i  + ":" + s)
        }
        if(arg1[i]["dateEn"] != arg2[i]["dateEn"]){
            throw("not equals " + i  + ":" + s)
        }
    }
}

assert_equal(getDateList(new Date("2018-09-21")) ,
  [ { dateJp: '09月27日', dateEn: '2018-09-27' },
    { dateJp: '09月28日', dateEn: '2018-09-28' },
    { dateJp: '09月29日', dateEn: '2018-09-29' },
    { dateJp: '09月30日', dateEn: '2018-09-30' },
    { dateJp: '10月01日', dateEn: '2018-10-01' },
    { dateJp: '10月02日', dateEn: '2018-10-02' },
    { dateJp: '10月03日', dateEn: '2018-10-03' },
    { dateJp: '10月04日', dateEn: '2018-10-04' } ])

assert_equal(getDateList(new Date("2018-09-22")) ,
  [ { dateJp: '09月27日', dateEn: '2018-09-27' },
    { dateJp: '09月28日', dateEn: '2018-09-28' },
    { dateJp: '09月29日', dateEn: '2018-09-29' },
    { dateJp: '09月30日', dateEn: '2018-09-30' },
    { dateJp: '10月01日', dateEn: '2018-10-01' },
    { dateJp: '10月02日', dateEn: '2018-10-02' },
    { dateJp: '10月03日', dateEn: '2018-10-03' },
    { dateJp: '10月04日', dateEn: '2018-10-04' } ])

assert_equal(getDateList(new Date("2018-09-23")) ,
  [ { dateJp: '09月27日', dateEn: '2018-09-27' },
    { dateJp: '09月28日', dateEn: '2018-09-28' },
    { dateJp: '09月29日', dateEn: '2018-09-29' },
    { dateJp: '09月30日', dateEn: '2018-09-30' },
    { dateJp: '10月01日', dateEn: '2018-10-01' },
    { dateJp: '10月02日', dateEn: '2018-10-02' },
    { dateJp: '10月03日', dateEn: '2018-10-03' },
    { dateJp: '10月04日', dateEn: '2018-10-04' } ])

assert_equal(getDateList(new Date("2018-09-24")) ,
  [ { dateJp: '09月27日', dateEn: '2018-09-27' },
    { dateJp: '09月28日', dateEn: '2018-09-28' },
    { dateJp: '09月29日', dateEn: '2018-09-29' },
    { dateJp: '09月30日', dateEn: '2018-09-30' },
    { dateJp: '10月01日', dateEn: '2018-10-01' },
    { dateJp: '10月02日', dateEn: '2018-10-02' },
    { dateJp: '10月03日', dateEn: '2018-10-03' },
    { dateJp: '10月04日', dateEn: '2018-10-04' } ])

assert_equal(getDateList(new Date("2018-09-25")) ,
  [ { dateJp: '09月28日', dateEn: '2018-09-28' },
    { dateJp: '09月29日', dateEn: '2018-09-29' },
    { dateJp: '09月30日', dateEn: '2018-09-30' },
    { dateJp: '10月01日', dateEn: '2018-10-01' },
    { dateJp: '10月02日', dateEn: '2018-10-02' },
    { dateJp: '10月03日', dateEn: '2018-10-03' },
    { dateJp: '10月04日', dateEn: '2018-10-04' },
    { dateJp: '10月05日', dateEn: '2018-10-05' } ])