package otherutils

import "time"

// GetYearDay returns a formatted integer representing year and day number (format: YYYYDDD)
func GetYearDay(tm *time.Time) int {
	year := tm.Year()
	day := tm.YearDay()
	return year*1000 + day
}

func GetYearDayByTs(ts int64) int {
	tm := time.Unix(ts, 0)
	return GetYearDay(&tm)
}

func GetYearWeek(tm *time.Time) int {
	y, w := tm.ISOWeek()
	return y*100 + w
}

func GetYearWeekByTs(ts int64) int {
	tm := time.Unix(ts, 0)
	return GetYearWeek(&tm)
}

func GetYearMonth(tm *time.Time) int {
	y, m, _ := tm.Date()
	return y*100 + int(m)
}

func GetYearMonthByTs(ts int64) int {
	tm := time.Unix(ts, 0)
	return GetYearMonth(&tm)
}

// 20141016
func GetYearMonthDay(tm *time.Time) int {
	y, m, d := tm.Date()
	return y*10000 + int(m)*100 + d
}

func IsSameDate(a *time.Time, b *time.Time) bool {
	a1 := GetYearMonthDay(a)
	b1 := GetYearMonthDay(b)
	return a1 == b1
}

// IsSameDateByTs checks if two timestamps belong to the same date
func IsSameDateByTs(a int64, b int64) bool {
	if a == b {
		return true
	}
	a1 := time.Unix(a, 0)
	b1 := time.Unix(b, 0)
	return IsSameDate(&a1, &b1)
}

// IsSameWeekByTs checks if two timestamps belong to the same ISO week
func IsSameWeekByTs(a int64, b int64) bool {
	if a == b {
		return true
	}
	a1 := time.Unix(a, 0)
	b1 := time.Unix(b, 0)
	return GetYearWeek(&a1) == GetYearWeek(&b1)
}

// GetZeroTime 获取指定时间的0时
func GetZeroTime(t time.Time) int64 {
	t2 := t.Unix()
	_, offsetSeconds := t.Zone()
	seconds := (t2 + int64(offsetSeconds)) % 86400
	return t2 - seconds
}

// DiffNatureDays 判断两个时间戳相差几天
func DiffNatureDays(t1, t2 int64) int {
	var secondsOfDay int64 = 86400
	if t1 == t2 {
		return 0
	}

	if t1 > t2 {
		t1, t2 = t2, t1
	}

	diffDays := 0
	secDiff := t2 - t1
	if secDiff > secondsOfDay {
		tmpDays := int(secDiff / secondsOfDay)
		t1 += int64(tmpDays) * secondsOfDay
		diffDays += tmpDays
	}

	st := time.Unix(t1, 0)
	et := time.Unix(t2, 0)
	dateFormatTpl := "20060102"
	if st.Format(dateFormatTpl) != et.Format(dateFormatTpl) {
		diffDays += 1
	}
	return diffDays
}

// GetWeekDay 时间是周几？范围1~7
func GetWeekDay(t time.Time) int {
	dayOfWeek := t.Weekday()

	// 将周日转换为7，其余依次加1
	dayNumber := int(dayOfWeek)
	if dayNumber == 0 { // 周日
		dayNumber = 7
	}
	return dayNumber
}

// GetWhichDayOfPeriod 活动开始后第几天,包括结束日
func CalcWhichDayOfPeriod(startTime int64, endTime int64) int64 {
	n := CalcDaysBetweenTs(startTime, endTime)
	return n + 1
}

// 计算从start日0点到endTime日0点，中间有几天，只计算日差值
func CalcDaysBetweenTime(startTime time.Time, endTime time.Time) int64 {
	endTime = time.Date(endTime.Year(), endTime.Month(), endTime.Day(), 0, 0, 0, 0, time.Local)
	startTime = time.Date(startTime.Year(), startTime.Month(), startTime.Day(), 0, 0, 0, 0, time.Local)
	return int64(endTime.Sub(startTime).Hours() / 24)
}

// 计算从start日0点到endTime日0点，中间有几天，只计算日差值
func CalcDaysBetweenTs(startTime int64, endTime int64) int64 {
	t1 := time.Unix(startTime, 0)
	t2 := time.Unix(endTime, 0)
	return CalcDaysBetweenTime(t1, t2)
}

// 计算从start日0点到endTime日0点，中间有几天，只计算日差值
func CalcDaysByYmd(ymd1 int32, ymd2 int32) int32 {
	t1 := GetTimeByDateInt(ymd1)
	t2 := GetTimeByDateInt(ymd2)
	return int32(CalcDaysBetweenTime(t1, t2))
}

func GetTimeByDateInt(date int32) time.Time {
	year := int(date / 10000)
	month := int(date / 100 % 100)
	day := int(date % 100)
	t := time.Date(year, time.Month(month), day, 0, 0, 0, 0, time.Local)
	return t
}

// func GetDateIntTimeStamp(timeStamp int64) int32 {
// 	_time := time.Unix(timeStamp, 0)
// 	return int32(_time.Year()*10000 + int(_time.Month())*100 + _time.Day())
// }

// func SubDays(endTime, startTime time.Time) int64 {
// 	endTime = time.Date(endTime.Year(), endTime.Month(), endTime.Day(), 0, 0, 0, 0, time.Local)
// 	startTime = time.Date(startTime.Year(), startTime.Month(), startTime.Day(), 0, 0, 0, 0, time.Local)
// 	return int64(endTime.Sub(startTime).Hours() / 24)
// }

// 获取这一天0点时的时间戳
func GetNowDayTimestamp() int64 {
	now := time.Now()
	year, month, day := now.Date()
	midnight := time.Date(year, month, day, 0, 0, 0, 0, now.Location())
	timestamp := midnight.Unix()
	return timestamp
}

// 获取指定周0点时间
func GetWeekZeroTime(timestamp int64) int64 {
	now := time.Unix(timestamp, 0)
	zeroTime := GetNowDayTimestamp()
	week := int64(now.Weekday())
	if week == 0 {
		week = 7
	}
	return zeroTime - ((week - 1) * 86400)
}