<?php

/**
 * ---------------------------------------------------------------------
 *
 * GLPI - Gestionnaire Libre de Parc Informatique
 *
 * http://glpi-project.org
 *
 * @copyright 2015-2023 Teclib' and contributors.
 * @copyright 2003-2014 by the INDEPNET Development Team.
 * @licence   https://www.gnu.org/licenses/gpl-3.0.html
 *
 * ---------------------------------------------------------------------
 *
 * LICENSE
 *
 * This file is part of GLPI.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * ---------------------------------------------------------------------
 */

namespace Glpi\CalDAV\Backend;

use Glpi\CalDAV\Node\Property;
use Glpi\CalDAV\Traits\CalDAVPrincipalsTrait;
use Glpi\CalDAV\Traits\CalDAVUriUtilTrait;
use Sabre\DAV\PropPatch;
use Sabre\DAVACL\PrincipalBackend\AbstractBackend;

/**
 * Principal backend for CalDAV server.
 *
 * @see http://sabre.io/dav/principals/
 *
 * @since 9.5.0
 */
class Principal extends AbstractBackend
{
    use CalDAVPrincipalsTrait;
    use CalDAVUriUtilTrait;

    const PRINCIPALS_ROOT = 'principals';
    const PREFIX_GROUPS   = self::PRINCIPALS_ROOT . '/groups';
    const PREFIX_USERS    = self::PRINCIPALS_ROOT . '/users';

    public function getPrincipalsByPrefix($prefixPath)
    {

        $principals = [];

        switch ($prefixPath) {
            case self::PREFIX_GROUPS:
                $groups_iterator = $this->getVisibleGroupsIterator();
                foreach ($groups_iterator as $group_fields) {
                    $principals[] = $this->getPrincipalFromGroupFields($group_fields);
                }
                break;
            case self::PREFIX_USERS:
                $users_iterator = $this->getVisibleUsersIterator();
                foreach ($users_iterator as $user_fields) {
                    $principals[] = $this->getPrincipalFromUserFields($user_fields);
                }
                break;
        }

        usort(
            $principals,
            function ($p1, $p2) {
                return $p1['id'] - $p2['id'];
            }
        );

        return $principals;
    }

    public function getPrincipalByPath($path)
    {

        $item = $this->getPrincipalItemFromUri($path);

        if (null === $item) {
            return;
        }

        return $this->getPrincipalFromItem($item);
    }

    public function updatePrincipal($path, PropPatch $propPatch)
    {
        throw new \Sabre\DAV\Exception\NotImplemented('Principal update is not implemented');
    }

    public function searchPrincipals($prefixPath, array $searchProperties, $test = 'allof')
    {

        throw new \Sabre\DAV\Exception\NotImplemented('Principal search is not implemented');
    }

    public function findByUri($uri, $principalPrefix)
    {
        throw new \Sabre\DAV\Exception\NotImplemented('Principal findByUri is not implemented');
    }

    public function getGroupMemberSet($path)
    {

        global $DB;

        $principal_itemtype = $this->getPrincipalItemtypeFromUri($path);
        $group_id           = $this->getGroupIdFromPrincipalUri($path);

        if (\Group::class !== $principal_itemtype) {
            return [];
        }

        $members_uris = [];

        $groups_iterator = $DB->request(
            [
                'FROM'  => \Group::getTable(),
                'WHERE' => [
                    'is_task'   => 1,
                    'groups_id' => $group_id,
                ] + getEntitiesRestrictCriteria(
                    \Group::getTable(),
                    'entities_id',
                    $_SESSION['glpiactiveentities'],
                    true
                ),
            ]
        );
        foreach ($groups_iterator as $group_fields) {
            $members_uris[] = $this->getGroupPrincipalUri($group_fields['id']);
        }

        $users_iterator = $DB->request(
            [
                'SELECT'     => [\User::getTableField('name')],
                'FROM'       => \User::getTable(),
                'INNER JOIN' => [
                    \Group_User::getTable() => [
                        'ON' => [
                            \User::getTable()       => 'id',
                            \Group_User::getTable() => 'users_id',
                        ],
                    ],
                ],
                'WHERE'     => [
                    \Group_User::getTableField('groups_id') => $group_id,
                ]
            ]
        );
        foreach ($users_iterator as $user_fields) {
            $members_uris[] = $this->getUserPrincipalUri($user_fields['name']);
        }

        return $members_uris;
    }

    public function getGroupMembership($path)
    {

        global $DB;

        $groups_query = [
            'SELECT'     => [\Group::getTableField('id')],
            'FROM'       => \Group::getTable(),
            'INNER JOIN' => [],
            'WHERE'      => [
                'is_task' => 1,
            ] + getEntitiesRestrictCriteria(
                \Group::getTable(),
                'entities_id',
                $_SESSION['glpiactiveentities'],
                true
            ),
        ];

        $principal_itemtype = $this->getPrincipalItemtypeFromUri($path);
        switch ($principal_itemtype) {
            case \Group::class:
                $groups_query['WHERE']['groups_id'] = $this->getGroupIdFromPrincipalUri($path);
                break;
            case \User::class:
                $groups_query['INNER JOIN'][\Group_User::getTable()] = [
                    'ON' => [
                        \Group::getTable()       => 'id',
                        \Group_User::getTable()  => 'groups_id',
                        [
                            'AND' => [
                                \Group_User::getTableField('users_id') => new \QuerySubQuery(
                                    [
                                        'SELECT' => 'id',
                                        'FROM'   => \User::getTable(),
                                        'WHERE'  => ['name' => $this->getUsernameFromPrincipalUri($path)],
                                    ]
                                ),
                            ],
                        ],
                    ]
                ];
                break;
            default:
                return []; // No groups if principal is not a user or a group
            break;
        }

        $groups_iterator = $DB->request($groups_query);

        $groups_uris = [];
        foreach ($groups_iterator as $group_fields) {
            $groups_uris[] = $this->getGroupPrincipalUri($group_fields['id']);
        }
        return $groups_uris;
    }

    public function setGroupMemberSet($path, array $members)
    {
        throw new \Sabre\DAV\Exception\NotImplemented('Group member set update is not implemented');
    }

    /**
     * Get principal object based on item.
     *
     * @param \CommonDBTM $item
     *
     * @return null|array
     */
    private function getPrincipalFromItem(\CommonDBTM $item)
    {

        $principal = null;

        switch (get_class($item)) {
            case \Group::class:
                $principal = $this->getPrincipalFromGroupFields($item->fields);
                break;
            case \User::class:
                $principal = $this->getPrincipalFromUserFields($item->fields);
                break;
        }

        return $principal;
    }

    /**
     * Get principal object based on user fields.
     *
     * @param array $user_fields
     *
     * @return array
     */
    private function getPrincipalFromUserFields(array $user_fields)
    {
        return [
            'id'                    => $user_fields['id'],
            'uri'                   => $this->getUserPrincipalUri($user_fields['name']),
            Property::USERNAME      => $user_fields['name'],
            Property::DISPLAY_NAME  => formatUserName(
                $user_fields['id'],
                $user_fields['name'],
                $user_fields['realname'],
                $user_fields['firstname']
            ),
            Property::PRIMARY_EMAIL => \UserEmail::getDefaultForUser($user_fields['id']),
            Property::CAL_USER_TYPE => 'INDIVIDUAL',
        ];
    }

    /**
     * Get principal object based on user fields.
     *
     * @param array $group_fields
     *
     * @return array
     */
    private function getPrincipalFromGroupFields(array $group_fields)
    {
        return [
            'id'                    => $group_fields['id'],
            'uri'                   => $this->getGroupPrincipalUri($group_fields['id']),
            Property::DISPLAY_NAME  => $group_fields['name'],
            Property::CAL_USER_TYPE => 'GROUP',
        ];
    }
}
