package utils

import (
	"slices"
	"time"
)

// IsOverlap 判断两个时间段是否有重叠
func IsOverlap(start1, end1, start2, end2 string) bool {
	layout := "2006-01-02"
	startTime1, _ := time.Parse(layout, start1)
	endTime1, _ := time.Parse(layout, end1)
	startTime2, _ := time.Parse(layout, start2)
	endTime2, _ := time.Parse(layout, end2)

	// 如果一个时间段的开始时间在另一个时间段之后，或结束时间在另一个时间段之前，则无重叠
	if startTime1.After(endTime2) || endTime1.Before(startTime2) {
		return false
	}

	return true
}

func GetMonthByOffset(offset int) time.Time {
	return time.Now().AddDate(0, offset, 0)
}

func GetDayByOffset(offset int) time.Time {
	return time.Now().AddDate(0, 0, offset)
}

// GetLastMonthPeriod 返回上个月的月初时间和月末时间
func GetLastMonthPeriod(now time.Time) (firstDay time.Time, lastDay time.Time) {
	// 获取本个月的第一天的日期（即本月月初）
	firstDayOfThisMonth := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())

	nextMonth := now.AddDate(0, 1, 0)
	// 获取下月第一天的日期（即下个月月初）
	firstDayOfNextMonth := time.Date(nextMonth.Year(), nextMonth.Month(), 1, 0, 0, 0, 0, now.Location())

	// 下个月月末时间即为本月月初减去一秒
	lastDayOfThisMonth := firstDayOfNextMonth.Add(-time.Second)

	return firstDayOfThisMonth, lastDayOfThisMonth
}

func GetMonthDuration(d time.Time) (duration int) {
	return d.AddDate(0, 1, -1).Day()
}

func CalcWorkHour(begin, end time.Time, dayOff []time.Weekday, cellHour float32) (workHour float32, workingCount int) {
	var currentTime = begin
	for {
		if currentTime.After(end) {
			break
		}
		if slices.Contains(dayOff, currentTime.Weekday()) {
			// nothing
		} else {
			workHour += cellHour
			workingCount++
		}
		currentTime = currentTime.AddDate(0, 0, 1) // .Add(24 * time.Hour)
	}

	return float32(workHour), workingCount
}