<?php

/**
 *  @author Dejan Marjanovic <dejan.marjanovic@gmail.com>
 *  @package eng5
 *  @name Webarto DateTime
 */

class WA_DT
{

    /**
    * Calculate shift span in one calendar day, if shift crosses midnight
    *
    * @return array
    */
    public static function shift_span($start, $end)
    {
        $time_diff = self::time_diff($start, $end);
        $time_diff = $time_diff['hours'];

        # ignore minutes, safe after we calculated difference
        $start = (int) $start;
        $end = (int) $end;

        if($start + $time_diff < 24)
            return array($time_diff);

        return array(
            abs($end - $time_diff),
            abs(($start + $time_diff) % 24)
        );
    }

    /**
    * Calculate shift span in hours (sort of TIMEDIFF MySQL)
    *
    * @return array
    */
    public static function time_diff($start, $end)
    {
        # do not ignore minutes
        $start = strtotime($start);
        $end = strtotime($end);

        $diff = abs($start - $end);
        $hours = floor($diff / 3600);
        $minutes = ($diff - ($hours * 3600)) / 60;

        $hours = $start > $end? 24 - $hours: $hours;

        return compact('hours', 'minutes');
    }

}