<?php

declare(strict_types=1);

/*
 * Chill is a software for social workers
 *
 * For the full copyright and license information, please view
 * the LICENSE file that was distributed with this source code.
 */

namespace Chill\MainBundle\Service\RollingDate;

use DateInterval;
use DateTimeImmutable;
use LogicException;
use UnexpectedValueException;

class RollingDateConverter implements RollingDateConverterInterface
{
    public function convert(?RollingDate $rollingDate): ?DateTimeImmutable
    {
        if (null === $rollingDate) {
            return null;
        }

        switch ($rollingDate->getRoll()) {
            case RollingDate::T_MONTH_CURRENT_START:
                return $this->toBeginOfMonth($rollingDate->getPivotDate());

            case RollingDate::T_MONTH_NEXT_START:
                return $this->toBeginOfMonth($rollingDate->getPivotDate()->add(new DateInterval('P1M')));

            case RollingDate::T_MONTH_PREVIOUS_START:
                return $this->toBeginOfMonth($rollingDate->getPivotDate()->sub(new DateInterval('P1M')));

            case RollingDate::T_QUARTER_CURRENT_START:
                return $this->toBeginOfQuarter($rollingDate->getPivotDate());

            case RollingDate::T_QUARTER_NEXT_START:
                return $this->toBeginOfQuarter($rollingDate->getPivotDate()->add(new DateInterval('P3M')));

            case RollingDate::T_QUARTER_PREVIOUS_START:
                return $this->toBeginOfQuarter($rollingDate->getPivotDate()->sub(new DateInterval('P3M')));

            case RollingDate::T_WEEK_CURRENT_START:
                return $this->toBeginOfWeek($rollingDate->getPivotDate());

            case RollingDate::T_WEEK_NEXT_START:
                return $this->toBeginOfWeek($rollingDate->getPivotDate()->add(new DateInterval('P1W')));

            case RollingDate::T_WEEK_PREVIOUS_START:
                return $this->toBeginOfWeek($rollingDate->getPivotDate()->sub(new DateInterval('P1W')));

            case RollingDate::T_YEAR_CURRENT_START:
                return $this->toBeginOfYear($rollingDate->getPivotDate());

            case RollingDate::T_YEAR_PREVIOUS_START:
                return $this->toBeginOfYear($rollingDate->getPivotDate()->sub(new DateInterval('P1Y')));

            case RollingDate::T_YEAR_NEXT_START:
                return $this->toBeginOfYear($rollingDate->getPivotDate()->add(new DateInterval('P1Y')));

            case RollingDate::T_TODAY:
                return $rollingDate->getPivotDate();

            case RollingDate::T_FIXED_DATE:
                if (null === $rollingDate->getFixedDate()) {
                    throw new LogicException('You must provide a fixed date when selecting a fixed date');
                }

                return $rollingDate->getFixedDate();

            default:
                throw new UnexpectedValueException(sprintf('%s rolling operation not supported', $rollingDate->getRoll()));
        }
    }

    private function toBeginOfMonth(DateTimeImmutable $date): DateTimeImmutable
    {
        return DateTimeImmutable::createFromFormat(
            'Y-m-d His',
            sprintf('%s-%s-01 000000', $date->format('Y'), $date->format('m'))
        );
    }

    private function toBeginOfQuarter(DateTimeImmutable $date): DateTimeImmutable
    {
        switch ((int) $date->format('n')) {
            case 1:
            case 2:
            case 3:
                $month = '01';

                break;

            case 4:
            case 5:
            case 6:
                $month = '04';

                break;

            case 7:
            case 8:
            case 9:
                $month = '07';

                break;

            case 10:
            case 11:
            case 12:
                $month = '10';

                break;

            default:
                throw new LogicException('this month is not valid: ' . $date->format('n'));
        }

        return DateTimeImmutable::createFromFormat(
            'Y-m-d His',
            sprintf('%s-%s-01 000000', $date->format('Y'), $month)
        );
    }

    private function toBeginOfWeek(DateTimeImmutable $date): DateTimeImmutable
    {
        if (1 === $dayOfWeek = (int) $date->format('N')) {
            return $date->setTime(0, 0, 0);
        }

        return $date
            ->sub(new DateInterval('P' . ($dayOfWeek - 1) . 'D'))
            ->setTime(0, 0, 0);
    }

    private function toBeginOfYear(DateTimeImmutable $date): DateTimeImmutable
    {
        return DateTimeImmutable::createFromFormat(
            'Y-m-d His',
            sprintf('%s-01-01 000000', $date->format('Y'))
        );
    }
}