<?php

class DateUtil {

    /**
     * 获取某个时间段内所有月份 (包含开头结尾月份)
     * @param minDate
     * @param maxDate
     * @return
     * @throws ParseException
     */
    public static function getMonthBetweenDates($minDate, $maxDate) {
        $sTime = strtotime(date('Y-m-01', strtotime($minDate)));
        $eTime = strtotime(date('Y-m-01', strtotime($maxDate)));
        $months = [];
        while ($sTime <= $eTime) {
            $months[] = date('Y-m', $sTime);
            $sTime = strtotime('next month', $sTime);
        }
        return $months;
    }

    /**
     * 获取某个时间段内所有月份 (包含开头月份，不包含结尾月份)
     * @param minDate
     * @param maxDate
     * @return
     * @throws ParseException
     */
    public static function getMonthBetweenDatesNotEnd($minDate, $maxDate) {
        $sTime = strtotime(date('Y-m-01', strtotime($minDate)));
        $eTime = strtotime(date('Y-m-01', strtotime($maxDate)));
        $months = [];
        while ($sTime < $eTime) {
            $months[] = date('Y-m', $sTime);
            $sTime = strtotime('next month', $sTime);
        }
        return $months;
    }

    /**
     * 获取某个时间段内所有月份 (不包含开头月份，包含结尾月份)
     * @param minDate
     * @param maxDate
     * @return
     * @throws ParseException
     */
    public static function getMonthBetweenDatesNotBegin($minDate, $maxDate) {
        $sTime = strtotime(date('Y-m-01', strtotime($minDate)));
        $eTime = strtotime(date('Y-m-01', strtotime($maxDate)));
        $months = [];
        $sTime = strtotime("next month", $sTime); //第一个月跳过
        while ($sTime <= $eTime) {
            $months[] = date('Y-m', $sTime);
            $sTime = strtotime('next month', $sTime);
        }
        return $months;
    }

    public static function getEveryMonthDayBetween($startTime, $endTime, $monthList) {
        $res = [];

        $min = new DateTime($startTime);
        $min->setTime(0, 0, 0);

        $max = new DateTime($endTime);
        $max->setTime(23, 59, 59);

        $curr = clone $min;

        while ($curr < $max) {
            $month = $curr->format('Y-m');

            if (in_array($month, $monthList)) {
                if (!isset($res[$month])) {
                    $res[$month] = 0;
                }
                $res[$month] ++;
            }

            $curr->modify('+1 day');
        }

        return $res;
    }

}