import dateUtil from '../../utils/date';

export const toDate = function(date) {
    date = new Date(date);
    if (isNaN(date.getTime())) return null;
    return date;
};

export const formatDate = function(date, format) {
    date = toDate(date);
    if (!date) return '';
    return dateUtil.format(date, format || 'yyyy-MM-dd');
};

export const parseDate = function(string, format) {
    return dateUtil.parse(string, format || 'yyyy-MM-dd');
};

export const getDayCountOfMonth = function(year, month) {
    return new Date(year, month + 1, 0).getDate();
};

export const getFirstDayOfMonth = function(date) {
    const temp = new Date(date.getTime());
    temp.setDate(1);
    return temp.getDay();
};

export const siblingMonth = function(src, diff) {
    const temp = new Date(src); // lets copy it so we don't change the original
    const newMonth = temp.getMonth() + diff;
    const newMonthDayCount = getDayCountOfMonth(temp.getFullYear(), newMonth);
    if (newMonthDayCount < temp.getDate()) {
        temp.setDate(newMonthDayCount);
    }
    temp.setMonth(newMonth);

    return temp;
};

export const prevMonth = function(src) {
    return siblingMonth(src, -1);
};

export const nextMonth = function(src) {
    return siblingMonth(src, 1);
};

export const initTimeDate = function() {
    const date = new Date();
    date.setHours(0);
    date.setMinutes(0);
    date.setSeconds(0);
    return date;
};