export function getWeek(time : Date) {
	let week = time.getDay() // 当前周几
	// week = (week - 1) < 0 ? 0 : (week - 1)
	if(week == 0) week = 7 // 0 表示周日
	return week
}

export function getCurrentMonth(time : Date) : number {
	let month = time.getMonth() + 1
	return month
}

export function getLastMonth(curDate : Date) {
	let lastDate = new Date()
	lastDate.setMonth(curDate.getMonth() - 1)
	return lastDate
}

export function getLastMonthDay(curDate : Date, offset : number) {
	let lastDate = new Date(curDate.getTime())
	lastDate.setHours(-24 * offset);
	return lastDate
}

export function getNextMonthDay(curDate : Date, offset : number) {
	let lastDate = new Date(curDate.getTime())
	lastDate.setHours(24 * offset);
	return lastDate
}


export function format(time : Date) {
	return `${time.getFullYear()}-${time.getMonth() + 1}-${time.getDate()}`
}

export function formatFull(time : Date) {
	const year = (time.getFullYear()) + ""
	const month = (time.getMonth() + 1) + ""
	const date = (time.getDate()) + ""
	const hour = (time.getHours()) + ""
	const minute = (time.getMinutes()) + ""
	const second = (time.getSeconds()) + ""
	return `${year}-${month.padStart(2, '0')}-${date.padStart(2, '0')} ${hour.padStart(2, '0')}:${minute.padStart(2, '0')}:${second.padStart(2, '0')}`
}

// 获取当前月份应该有多少天
export function getCurMonthDayNum(time : Date) : number {
	let day = 31;
	let month = time.getMonth() + 1
	let year = time.getFullYear()
	if ([1, 3, 5, 7, 8, 10, 12].indexOf(month) != -1) {
		day = 31;
	} else if ([4, 6, 9, 11].indexOf(month) != -1) {
		day = 30;
	} else if (year % 4 == 0) {
		day = 29
	} else {
		day = 28
	}
	return day
}

export function generateDate<T = Date>(_nowDate : Date | string | number, format : (date : Date) => T = (v : Date) => (v as T)) {
	if (typeof _nowDate === "string" || typeof _nowDate === "number") {
		_nowDate = new Date(_nowDate as string)
	}

	const allDate : T[] = []

	let firstDate = new Date(_nowDate.getTime())
	firstDate.setDate(1)
	const firstWeek = getWeek(firstDate)
	console.log(firstDate.getTime());
	for (var i = 1; i < firstWeek; i++) {
		const date = getLastMonthDay(firstDate, i)
		allDate.unshift(format(new Date(date.getTime())) as T)
	}

	let curDate = new Date(_nowDate.getTime())
	const allDay = getCurMonthDayNum(curDate)
	for (var i = 1; i <= getCurMonthDayNum(curDate); i++) {
		curDate.setDate(i)
		allDate.push(format(new Date(curDate.getTime())) as T)
	}

	let endDate = new Date(_nowDate.getTime())
	endDate.setDate(allDay)
	const endWeek = 7 - getWeek(endDate)
	for (var i = 1; i <= endWeek; i++) {
		const date = getNextMonthDay(endDate, i)
		allDate.push(format(new Date(date.getTime())) as T)
	}
	// 至少6行
	if (~~(allDate.length / 7) < 6) {
		for (var i = endWeek + 1; i < endWeek + 1 + 7; i++) {
			const date = getNextMonthDay(endDate, i)
			allDate.push(format(new Date(date.getTime())) as T)
		}
	}

	return allDate
}