gnu-social/components/Feed/Util/FeedController.php

<?php

declare(strict_types = 1);

// {{{ License
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social 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.
//
// GNU social 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 GNU social.  If not, see <http://www.gnu.org/licenses/>.
// }}}

/**
 * Base class for feed controllers
 *
 * @package  GNUsocial
 * @category Controller
 *
 * @author    Hugo Sales <hugo@hsal.es>
 * @copyright 2021 Free Software Foundation, Inc http://www.fsf.org
 * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
 */

namespace Component\Feed\Util;

use App\Core\Controller;
use App\Core\Event;
use App\Core\Log;
use App\Core\VisibilityScope;
use App\Entity\Actor;
use App\Util\Common;
use function array_key_exists;

abstract class FeedController extends Controller
{
    /**
     * Post-processing of the result of a feed controller, to remove any
     * notes or actors the user specified, as well as format the raw
     * list of notes into a usable format
     */
    public static function postProcess(array $result): array
    {
        $actor = Common::actor();

        if (array_key_exists('notes', $result)) {
            $notes = $result['notes'];
            self::enforceScope($notes, $actor);
            Event::handle('FilterNoteList', [$actor, &$notes, $result['request']]);
            Event::handle('FormatNoteList', [$notes, &$result['notes']]);
        }

        return $result;
    }

    private static function enforceScope(array &$notes, ?Actor $actor): void
    {
        $filtered_notes = [];
        foreach($notes as $note) {
            switch($note->getScope()) {
                case VisibilityScope::LOCAL: // The controller handles it if private
                case VisibilityScope::PUBLIC:
                    $filtered_notes[] = $note;
                    break;
                case VisibilityScope::ADDRESSEE:
                    // If the actor is logged in and
                    if (!is_null($actor) &&
                        (
                            // Is either the author Or
                            $note->getActorId() == $actor->getId() ||
                            // one of the targets
                            in_array($actor->getId(), $note->getNotificationTargetIds())
                        )) {
                        $filtered_notes[] = $note;
                    }
                    break;
                case VisibilityScope::GROUP:
                    // Only for the group to see
                    break;
                case VisibilityScope::COLLECTION: // no break
                case VisibilityScope::MESSAGE:
                    // Only for the collection to see (they will only find it in their notifications)
                    break;
                default:
                    Log::warning("Unknown scope found: {$note->getScope()}.");
            }
        }
        // Replace notes with filtered ones I/O
        $notes = $filtered_notes;
    }
}