parking calculate

<?php

use Carbon\Carbon;

date_default_timezone_set('Europe/Moscow');
require 'vendor/autoload.php';

class Parking
{
    protected $baseHourPrice;

    public function __construct($baseHourPrice)
    {
        $this->baseHourPrice = $baseHourPrice;
    }

    /**
     * @var Rule[]
     */
    private $rules = [];

    public function addRule(Rule $rule)
    {
        $this->rules[] = $rule;
        return $this;
    }


    function calculate(Carbon $begin, Carbon $end)
    {
        /**
         * dates list when something was changed
         * @var $dates Carbon[]
         */
        $dates = [$begin->getTimestamp() => $begin];
        $current = $begin->copy();
        while ($current < $end) {
            foreach ($this->rules as $rule) {
                if ($rule->shouldBeApplied($current)) {
                    foreach ([$rule->getBegin($current), $rule->getEnd($current)] as $point) {
                        if (!isset($dates[$point->getTimestamp()]) && $point->between($begin, $end)) {
                            $dates[$point->getTimestamp()] = $point;
                        }
                    }
                }
            }
            $current = $current->copy()->addDay(1);
        }

        $dates[$end->getTimestamp()] = $end;
        ksort($dates);

        // calculate result
        $previous = null;
        $total = 0;

        foreach ($dates as $current) {
            if ($previous) {

                $hours = $current->diffInMinutes($previous) / 60;
                $sum = $this->baseHourPrice * $hours;

                $rules = [];
                foreach ($this->rules as $rule) {
                    if ($rule->shouldBeApplied($current)) {
                        if ($rule->getBegin($current) < $current && $rule->getEnd($current) >= $current) {
                            $sum = $rule->changeSum($sum, $hours);
                            $rules[] = get_class($rule);
                        }
                    }
                }

                echo $previous, ' - ', $current, PHP_EOL;
                echo json_encode(compact('hours', 'sum', 'rules')), PHP_EOL, PHP_EOL;

                $total += $sum;
            }
            $previous = $current;
        }
        echo 'Total is: ', $total, PHP_EOL;

        return $total;
    }
}

interface Rule
{
    public function shouldBeApplied(Carbon $date);

    public function getBegin(Carbon $date);

    public function getEnd(Carbon $date);

    public function changeSum($sum);
}

/**
 * Pay twice when use parking during hot hours
 * Class HighLoadRule
 */
class HighLoadRule implements Rule
{
    function shouldBeApplied(Carbon $date)
    {
        return $date->isWeekday();
    }

    function getBegin(Carbon $date)
    {
        return $date->copy()->setTime(17, 0, 0);
    }

    function getEnd(Carbon $date)
    {
        return $date->copy()->setTime(22, 0, 0);
    }

    function changeSum($sum)
    {
        return $sum * 2;
    }
}

class WeekendRule implements Rule
{

    function shouldBeApplied(Carbon $date)
    {
        return $date->isWeekend();
    }

    function getBegin(Carbon $date)
    {
        return $date->copy()->setTime(0, 0, 0);
    }

    function getEnd(Carbon $date)
    {
        return $date->copy()->setTime(24, 0, 0);
    }

    function changeSum($sum)
    {
        return $sum / 2;
    }
}

class GoldHoursRule implements Rule
{

    function shouldBeApplied(Carbon $date)
    {
        return true;
    }

    function getBegin(Carbon $date)
    {
        return $date->copy()->setTime(18, 0, 0);
    }

    function getEnd(Carbon $date)
    {
        return $date->copy()->setTime(19, 0, 0);
    }

    function changeSum($sum)
    {
        return $sum * 3;
    }
}

class GoodMorningRule implements Rule
{

    function shouldBeApplied(Carbon $date)
    {
        return true;
    }

    function getBegin(Carbon $date)
    {
        return $date->copy()->setTime(9, 0, 0);
    }

    function getEnd(Carbon $date)
    {
        return $date->copy()->setTime(10, 0, 0);
    }

    function changeSum($sum)
    {
        return 0;
    }
}

$result = with(new Parking(120)) // parking with 120 RUB per hours base price
->addRule(new WeekendRule()) // on weekdays from 17 to 22 pay twice higher
->addRule(new HighLoadRule()) // on weekends pay twice lower
->addRule(new GoldHoursRule()) // any day from 18 to 19 price multiplies by 3
->addRule(new GoodMorningRule()) // any day from 9 to 10 parking is free
->calculate(
    // 2015-07-24 13:30:00
    Carbon::createFromTime(13, 30, 00)->setDate(2015, 7, 23),

    // 2015-07-25 17:00:00
    Carbon::createFromTime(21, 00, 00)->setDate(2015, 7, 25)
);

//
// 2015-07-23 13:30:00 - 2015-07-23 17:00:00
// {"hours":3.5,"sum":420,"rules":[]}
//
// 2015-07-23 17:00:00 - 2015-07-23 18:00:00
// {"hours":1,"sum":240,"rules":["HighLoadRule"]}
//
// 2015-07-23 18:00:00 - 2015-07-23 19:00:00
// {"hours":1,"sum":720,"rules":["HighLoadRule","GoldHoursRule"]}
//
// 2015-07-23 19:00:00 - 2015-07-23 22:00:00
// {"hours":3,"sum":720,"rules":["HighLoadRule"]}
//
// 2015-07-23 22:00:00 - 2015-07-24 09:00:00
// {"hours":11,"sum":1320,"rules":[]}
//
// 2015-07-24 09:00:00 - 2015-07-24 10:00:00
// {"hours":1,"sum":0,"rules":["GoodMorningRule"]}
//
// 2015-07-24 10:00:00 - 2015-07-24 17:00:00
// {"hours":7,"sum":840,"rules":[]}
//
// 2015-07-24 17:00:00 - 2015-07-24 18:00:00
// {"hours":1,"sum":240,"rules":["HighLoadRule"]}
//
// 2015-07-24 18:00:00 - 2015-07-24 19:00:00
// {"hours":1,"sum":720,"rules":["HighLoadRule","GoldHoursRule"]}
//
// 2015-07-24 19:00:00 - 2015-07-24 22:00:00
// {"hours":3,"sum":720,"rules":["HighLoadRule"]}
//
// 2015-07-24 22:00:00 - 2015-07-25 00:00:00
// {"hours":2,"sum":240,"rules":[]}
//
// 2015-07-25 00:00:00 - 2015-07-25 09:00:00
// {"hours":9,"sum":540,"rules":["WeekendRule"]}
//
// 2015-07-25 09:00:00 - 2015-07-25 10:00:00
// {"hours":1,"sum":0,"rules":["WeekendRule","GoodMorningRule"]}
//
// 2015-07-25 10:00:00 - 2015-07-25 18:00:00
// {"hours":8,"sum":480,"rules":["WeekendRule"]}
//
// 2015-07-25 18:00:00 - 2015-07-25 19:00:00
// {"hours":1,"sum":180,"rules":["WeekendRule","GoldHoursRule"]}
//
// 2015-07-25 19:00:00 - 2015-07-25 21:00:00
// {"hours":2,"sum":120,"rules":["WeekendRule"]}
//
// Total is: 7500