import { parseDate } from '@/utils/parseDate'
import dayjs from 'dayjs'

import isLeapYear from 'dayjs/plugin/isLeapYear'

dayjs.extend(isLeapYear)

const DATE_SEPARATORS = /[- /.]/
/** Matches DD/MM/YYYY with one of the DATE_SEPARATORS */
export const DATE_FORMAT_REGEX
	= /(0[1-9]|[12][0-9]|3[01])[- /.](0[1-9]|1[012])[- /.]\d{4}/

export enum DateErrorCodes {
	WRONG_FORMAT = 'wrongFormat',
	MONTH_NOT_MATCH = 'monthNotMatch',
	NOT_LEAP_YEAR = 'notALeapYear',
}

/** Check if a date is valid */
export function isDateValid(date: string): string | true {
	if (!date.match(DATE_FORMAT_REGEX)) {
		return DateErrorCodes.WRONG_FORMAT
	}

	const DAYS_IN_MONTH = [
		31,
		28, // Check leap year later
		31,
		30,
		31,
		30,
		31,
		31,
		30,
		31,
		30,
		31,
	]

	const parsedDate = date.split(DATE_SEPARATORS) as [string, string, string]

	const day = parseInt(parsedDate[0], 10)
	const month = parseInt(parsedDate[1], 10)

	if (month !== 2) {
		if (day > DAYS_IN_MONTH[month - 1]!) {
			return DateErrorCodes.MONTH_NOT_MATCH
		}
		else {
			return true
		}
	}
	else {
		const parsed = parseDate(date)
		const isLeap = parsed.isLeapYear()

		if (isLeap && day > 29) {
			return DateErrorCodes.MONTH_NOT_MATCH
		}

		if (!isLeap && day >= 29) {
			return DateErrorCodes.NOT_LEAP_YEAR
		}

		return true
	}
}