php計算兩個時間段內的 工作日 工作小時

<?php

class WorkTime
{
    // 定義工作日 [1, 2, 3, 4, 5, 6, 0]
    public $week_workingday = [1, 2, 3, 4, 5];

    // 定義上下班時間
    public $on_duty_time = '9:00:00';
    public $off_duty_time = '18:00:00';

    //每天工作時長
    public $oneday_hours = null;

    public function __construct()
    {
        if (empty($this->oneday_hours)) {
            $this->oneday_hours = $this->off_duty_time - $this->on_duty_time;
        }
    }


    public function get_working_hours(int $start_time, int $over_time)
    {
        // 如果工作日列表為空 返回0
        $workingdays = $this->workingdays($start_time, $over_time);

        if (empty($workingdays)) {
            return 0;
        }

        // 如果開始時間不是工作日,將開始時間調整為第一個工作日的上班時間
        // 如果截止時間不是工作日,將開始時間調整為最后一個工作日的下班時間
        if (!in_array(date('Y/m/d', $start_time), $workingdays)) {
            $start_time = strtotime($workingdays[0] . ' ' . $this->on_duty_time);
        }

        if (!in_array(date('Y/m/d', $over_time), $workingdays)) {
            $over_time = strtotime(end($workingdays) . ' ' . $this->off_duty_time);
        }

        // 如果開始時間與截止時間是同一天,直接計算
        // 反之分別計算開始時間與截止時間
        if (date('Y/m/d', $start_time) == date('Y/m/d', $over_time)) {
            $sec = $over_time - $start_time;
            if ($sec > 3600 * $this->oneday_hours) {
                $sec = 3600 * $this->oneday_hours;
            }
            // 昨天到了計算秒數
        } else {
            // 計算開始日工作時間
            $start_day_sec = strtotime($workingdays[0] . ' ' . $this->off_duty_time) - $start_time;
            if ($start_day_sec > 3600 * $this->oneday_hours) {
                $start_day_sec = 3600 * $this->oneday_hours;
            }
            // 計算截止日工作時間
            $over_day_sec = $over_time - strtotime(end($workingdays) . ' ' . $this->on_duty_time);
            if ($over_day_sec > 3600 * $this->oneday_hours) {
                $over_day_sec = 3600 * $this->oneday_hours;
            }

            $all_day_sec = ((count($workingdays) - 2) * $this->oneday_hours) * 3600;
            $sec         = $start_day_sec + $over_day_sec + $all_day_sec;
        }

        return $sec / 3600;
    }

    # 計算工作日(包含開始與截止日期)
    protected function workingdays($start_time, $over_time)
    {
        $start_time = strtotime('-1 day', $start_time);
        $over_time  = strtotime('-1 day', $over_time);

        $new_workingdays = $this->new_workingdays();
        $new_holidays    = $this->new_holidays();
        $workingdays     = [];

        while ($start_time < $over_time) {
            $start_time     = strtotime('+1 day', $start_time);
            $is_holidays    = in_array(date('w', $start_time), $this->week_workingday) && !in_array(date('Y/m/d', $start_time), $new_holidays);
            $is_workingdays = in_array(date('Y/m/d', $start_time), $new_workingdays);

            if ($is_holidays || $is_workingdays) {
                $workingdays[] = date('Y/m/d', $start_time);
            }
        }

        return $workingdays;
    }


    # 新增工作日
    protected function new_workingdays()
    {
        $days = [
            '2020/05/09',
        ];

        return $days;
    }

    # 新增休息日
    protected function new_holidays()
    {
        $days = [
            '2020/05/01',
            '2020/05/04',
            '2020/05/05',
        ];

        return $days;
    }

}

$start_time = strtotime('2020-05-06 10:00:00');
$over_time  = strtotime('2020-05-11 18:00:00');

$work          = new WorkTime();
$working_hours = $work->get_working_hours($start_time, $over_time);

var_dump($working_hours);