import { Ornellember } from '..';

export const getDaysBeforeCurrentMonth = (currentMonthIndex: number, isLeapYear: boolean): number => {

	// then calculate the days of all the months before.
	const daysInMonths = [
		31, // January
		isLeapYear ? 29 : 28, //February
		31, // March
		30, // April
		31, // May
		30, // June
		31, // July
		31, // August
		30, // September
		31, // October
		30, // November
		31 // December
	];

	// how many days before the current month?

	let daysBeforeCurrentMonth = 0;

	for (let i=0; i < currentMonthIndex; i++) {
		daysBeforeCurrentMonth += daysInMonths[i];
	}

	return daysBeforeCurrentMonth;
};

export const isLeapYear = (date: Date): boolean =>  {
	return (date.getFullYear() % 4) === 0;
};

export const getDayNumber = (date: Date) => {
	// first determine if it is a leap year
	const isCurrentLeapYear = isLeapYear(date);
	const currentMonth = date.getMonth();

	// then determine how many days happened before this current month started
	const daysBeforeCurrentMonth = getDaysBeforeCurrentMonth(currentMonth, isCurrentLeapYear);
    
	const dayOfMonth = date.getDate();

	return daysBeforeCurrentMonth + dayOfMonth;

};

export const convertDay = (dayNumber: number) : { day: number, month: string } => {
	const monthLength = 28;
    
	let monthIndex = Math.floor((dayNumber - 1) / monthLength);

	// make sure there are only 13 months (additional days can be added to month 12)
	if (monthIndex > 12) {
		monthIndex = 12;
	}

	const dayOfMonth = dayNumber - (monthIndex * monthLength);

	const monthLetter = String.fromCharCode(97 + monthIndex).toUpperCase();

	return {
		day: dayOfMonth,
		month: monthLetter
	};
};

/*
    This returns the date a new format that I invented, largely based on the International Fixed Calendar
    https://en.wikipedia.org/wiki/International_Fixed_Calendar
    It's mostly a joke but also I think it is logical and fun
*/
export const getOrnellemberDay = (date: Date) : Partial<Ornellember> => {
	const dayNumber = getDayNumber(date);
	return convertDay(dayNumber);
};