<?php
/************************************************************************
 * This file is part of EspoCRM.
 *
 * EspoCRM – Open Source CRM application.
 * Copyright (C) 2014-2024 Yurii Kuznietsov, Taras Machyshyn, Oleksii Avramenko
 * Website: https://www.espocrm.com
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License version 3.
 *
 * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
 * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
 ************************************************************************/

namespace Espo\Tools\WorkingTime;

use Espo\Core\Utils\Config;
use Espo\Entities\Team;
use Espo\Entities\User;
use Espo\Entities\WorkingTimeCalendar;
use Espo\Entities\WorkingTimeRange;
use Espo\ORM\EntityManager;
use Espo\ORM\Query\Part\Condition;
use Espo\ORM\Query\Part\Expression;
use Espo\ORM\Query\Part\Where\OrGroup;
use Espo\Tools\WorkingTime\Calendar\WorkingWeekday;
use Espo\Tools\WorkingTime\Calendar\WorkingDate;
use Espo\Core\Field\Date;
use Espo\Tools\WorkingTime\Util\CalendarUtil;
use DateTimeZone;
use Exception;
use RuntimeException;

class UserCalendar implements Calendar
{
    private ?WorkingTimeCalendar $workingTimeCalendar = null;
    private ?CalendarUtil $util = null;

    /** @var ?array{WorkingDate[], WorkingDate[]} */
    private ?array $cache = null;
    private ?string $cacheKey = null;
    private DateTimeZone $timezone;

    public function __construct(
        private User $user,
        private EntityManager $entityManager,
        private Config $config,
        Config\ApplicationConfig $applicationConfig,
    ) {
        try {
            $this->timezone = new DateTimeZone($applicationConfig->getTimeZone());
        } catch (Exception $e) {
            throw new RuntimeException($e->getMessage());
        }

        $this->init();

        if (!$this->workingTimeCalendar) {
            $this->initDefault();
        }

        if ($this->workingTimeCalendar) {
            $this->util = new CalendarUtil($this->workingTimeCalendar);

            $this->timezone = $this->workingTimeCalendar->getTimeZone() ?? $this->timezone;
        }
    }

    private function init(): void
    {
        $workingTimeCalendarLink = $this->user->getWorkingTimeCalendar();

        if ($workingTimeCalendarLink) {
            $this->workingTimeCalendar = $this->entityManager
                ->getRepositoryByClass(WorkingTimeCalendar::class)
                ->getById($workingTimeCalendarLink->getId());

            if ($this->workingTimeCalendar) {
                return;
            }
        }

        $defaultTeamLink = $this->user->getDefaultTeam();

        if (!$defaultTeamLink) {
            return;
        }

        $team = $this->entityManager
            ->getRepositoryByClass(Team::class)
            ->getById($defaultTeamLink->getId());

        if (!$team) {
            return;
        }

        $workingTimeCalendarLink = $team->getWorkingTimeCalendar();

        if (!$workingTimeCalendarLink) {
            return;
        }

        $this->workingTimeCalendar = $this->entityManager
            ->getRepositoryByClass(WorkingTimeCalendar::class)
            ->getById($workingTimeCalendarLink->getId());
    }

    private function initDefault(): void
    {
        $id = $this->config->get('workingTimeCalendarId');

        if (!$id) {
            return;
        }

        $this->workingTimeCalendar = $this->entityManager->getEntityById(WorkingTimeCalendar::ENTITY_TYPE, $id);
    }

    public function isAvailable(): bool
    {
        return $this->workingTimeCalendar !== null;
    }

    public function getTimezone(): DateTimeZone
    {
        return $this->timezone;
    }

    /**
     * @return WorkingWeekday[]
     */
    public function getWorkingWeekdays(): array
    {
        if ($this->workingTimeCalendar === null) {
            return [];
        }

        return $this->workingTimeCalendar->getWorkingWeekdays();
    }

    /**
     * @return WorkingDate[]
     */
    public function getNonWorkingDates(Date $from, Date $to): array
    {
        if ($this->workingTimeCalendar === null) {
            return [];
        }

        return $this->getDates($from, $to)[0];
    }

    /**
     * @return WorkingDate[]
     */
    public function getWorkingDates(Date $from, Date $to): array
    {
        if ($this->workingTimeCalendar === null) {
            return [];
        }

        return $this->getDates($from, $to)[1];
    }

    /**
     * @return array{WorkingDate[], WorkingDate[]}
     */
    private function getDates(Date $from, Date $to): array
    {
        $cacheKey = $from->toString() . '-' . $to->toString();

        if ($this->cacheKey === $cacheKey) {
            assert($this->cache !== null);

            return $this->cache;
        }

        $notWorkingList = [];
        $workingList = [];

        $listForUser = $this->fetchUserRanges($from, $to);
        $list = $this->fetchRanges($from, $to);

        foreach ($listForUser as $range) {
            $dates = $this->rangeToDates($range);

            if ($range->getType() === WorkingTimeRange::TYPE_NON_WORKING) {
                $notWorkingList = array_merge($notWorkingList, $dates);

                continue;
            }

            $workingList = array_merge($workingList, $dates);
        }

        $metMap = [];

        foreach (array_merge($notWorkingList, $workingList) as $date) {
            $metMap[$date->getDate()->getString()] = true;
        }

        foreach ($list as $range) {
            $dates = array_filter(
                $this->rangeToDates($range),
                function (WorkingDate $date) use ($metMap) {
                    return !array_key_exists($date->getDate()->toString(), $metMap);
                }
            );

            if ($range->getType() === WorkingTimeRange::TYPE_NON_WORKING) {
                $notWorkingList = array_merge($notWorkingList, $dates);

                continue;
            }

            $workingList = array_merge($workingList, $dates);
        }

        $this->cacheKey = $cacheKey;
        $this->cache = [$notWorkingList, $workingList];

        return $this->cache;
    }

    /**
     * @param WorkingTimeRange $range
     * @return WorkingDate[]
     */
    private function rangeToDates(WorkingTimeRange $range): array
    {
        if (!$this->util) {
            return [];
        }

        return $this->util->rangeToDates($range);
    }

    /**
     * @return WorkingTimeRange[]
     */
    private function fetchUserRanges(Date $from, Date $to): array
    {
        $list = [];

        $collection = $this->entityManager
            ->getRDBRepositoryByClass(WorkingTimeRange::class)
            ->leftJoin('users')
            ->where(
                Condition::equal(
                    Expression::column('users.id'),
                    $this->user->getId()
                )
            )
            ->where(
                OrGroup::create(
                    Condition::greaterOrEqual(
                        Expression::column('dateEnd'),
                        $from->toString()
                    ),
                    Condition::lessOrEqual(
                        Expression::column('dateStart'),
                        $to->toString()
                    ),
                )
            )
            ->find();

        foreach ($collection as $entity) {
            $list[] = $entity;
        }

        return $list;
    }

    /**
     * @return WorkingTimeRange[]
     */
    private function fetchRanges(Date $from, Date $to): array
    {
        if ($this->workingTimeCalendar === null) {
            return [];
        }

        $list = [];

        $collection = $this->entityManager
            ->getRDBRepositoryByClass(WorkingTimeRange::class)
            ->leftJoin('calendars')
            ->where(
                Condition::equal(
                    Expression::column('calendars.id'),
                    $this->workingTimeCalendar->getId()
                )
            )
            ->where(
                OrGroup::create(
                    Condition::greaterOrEqual(
                        Expression::column('dateEnd'),
                        $from->toString()
                    ),
                    Condition::lessOrEqual(
                        Expression::column('dateStart'),
                        $to->toString()
                    ),
                )
            )
            ->find();

        foreach ($collection as $entity) {
            $list[] = $entity;
        }

        return $list;
    }
}
