import { addMonths, addYears, getMonth, getYear, set, subMonths, subYears } from 'date-fns';

import { UseMonthYearPick, VueEmit } from '../../interfaces';
import { isDateAfter, isDateBefore, isDateEqual } from '../../utils/date-utils';

export const useMontYearPick = (props: UseMonthYearPick, emit: VueEmit) => {
    const recursiveMonthAdjust = (date: Date, increment: boolean): Date => {
        let monthDate = date;
        if (props.filters.months.includes(getMonth(monthDate))) {
            monthDate = increment ? addMonths(date, 1) : subMonths(date, 1);
            return recursiveMonthAdjust(monthDate, increment);
        }
        return monthDate;
    };

    const recursiveYearAdjust = (date: Date, increment: boolean): Date => {
        let yearDate = date;
        if (props.filters.years.includes(getYear(yearDate))) {
            yearDate = increment ? addYears(date, 1) : subYears(date, 1);
            return recursiveYearAdjust(yearDate, increment);
        }
        return yearDate;
    };

    const getDateForCompare = (propValue: 'minDate' | 'maxDate', month: number, year: number): [Date, Date] => {
        return [new Date(props[propValue]), set(new Date(), { month, year })];
    };

    const validateMonthYear = (month: number, year: number): void => {
        if (props.preventMinMaxNavigation && (props.minDate || props.maxDate)) {
            if (
                props.maxDate &&
                (isDateAfter(...getDateForCompare('maxDate', month, year)) ||
                    isDateEqual(...getDateForCompare('maxDate', month, year)))
            ) {
                updateMonthYear(month, year);
            }
            if (
                (props.minDate && isDateBefore(...getDateForCompare('minDate', month, year))) ||
                isDateEqual(...getDateForCompare('minDate', month, year))
            ) {
                updateMonthYear(month, year);
            }
        } else {
            updateMonthYear(month, year);
        }
    };

    const handleMonthYearChange = (isNext: boolean): void => {
        const initialDate = set(new Date(), { month: props.month, year: props.year });
        let date = isNext ? addMonths(initialDate, 1) : subMonths(initialDate, 1);

        let month = getMonth(date);
        let year = getYear(date);

        if (props.filters.months.includes(month)) {
            date = recursiveMonthAdjust(date, isNext);
            month = getMonth(date);
            year = getYear(date);
        }

        if (props.filters.years.includes(year)) {
            date = recursiveYearAdjust(date, isNext);
            year = getYear(date);
        }
        validateMonthYear(month, year);
    };

    const updateMonthYear = (month: number, year: number): void => {
        emit('update:month', month);
        emit('update:year', year);
    };

    return { handleMonthYearChange };
};