<?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/>.
// }}}
/**
* ActivityPub implementation for GNU social
*
* @package GNUsocial
* @category ActivityPub
*
* @author Diogo Peralta Cordeiro <@diogo.site>
* @copyright 2021 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
namespace Plugin\ActivityPub\Util\Model;
use ActivityPhp\Type;
use ActivityPhp\Type\AbstractObject;
use App\Core\Event;
use App\Core\Router\Router;
use App\Entity\Activity as GSActivity;
use App\Util\Exception\ClientException;
use App\Util\Exception\NoSuchActorException;
use App\Util\Exception\NotFoundException;
use App\Util\Exception\NotImplementedException;
use DateTimeInterface;
use InvalidArgumentException;
use Plugin\ActivityPub\ActivityPub;
use Plugin\ActivityPub\Entity\ActivitypubActivity;
use Plugin\ActivityPub\Util\Model;
use Symfony\Contracts\HttpClient\Exception\ClientExceptionInterface;
use Symfony\Contracts\HttpClient\Exception\RedirectionExceptionInterface;
use Symfony\Contracts\HttpClient\Exception\ServerExceptionInterface;
use Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface;
/**
* This class handles translation between JSON and ActivityPub Activities
*
* @copyright 2021 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
class Activity extends Model
{
/**
* Create an Entity from an ActivityStreams 2.0 JSON string
* This will persist new GSActivities, GSObjects, and APActivity
*
* @throws ClientExceptionInterface
* @throws NoSuchActorException
* @throws RedirectionExceptionInterface
* @throws ServerExceptionInterface
* @throws TransportExceptionInterface
*/
public static function fromJson(string|AbstractObject $json, array $options = []): ActivitypubActivity
{
$type_activity = \is_string($json) ? self::jsonToType($json) : $json;
// Ditch known activities
$ap_act = ActivitypubActivity::getByPK(['activity_uri' => $type_activity->get('id')]);
if (!\is_null($ap_act)) {
return $ap_act;
}
// Find Actor and Object
$actor = ActivityPub::getActorByUri($type_activity->get('actor'));
$type_object = $type_activity->get('object');
if (\is_string($type_object)) { // Retrieve it
$type_object = ActivityPub::getObjectByUri($type_object, try_online: true);
} else { // Encapsulated, if we have it locally, prefer it
$type_object = ActivityPub::getObjectByUri($type_object->get('id'), try_online: false) ?? $type_object;
}
if (($type_object instanceof Type\AbstractObject)) { // It's a new object apparently
if (Event::handle('NewActivityPubActivity', [$actor, $type_activity, $type_object, &$ap_act]) !== Event::stop) {
return self::handle_core_activity($actor, $type_activity, $type_object, $ap_act);
}
} else { // Object was already stored locally then
if (Event::handle('NewActivityPubActivityWithObject', [$actor, $type_activity, $type_object, &$ap_act]) !== Event::stop) {
return self::handle_core_activity($actor, $type_activity, $type_object, $ap_act);
}
}
return $ap_act;
}
private static function handle_core_activity(\App\Entity\Actor $actor, AbstractObject $type_activity, mixed $type_object, ?ActivitypubActivity &$ap_act): ActivitypubActivity
{
switch ($type_activity->get('type')) {
case 'Create':
ActivityCreate::handle_core_activity($actor, $type_activity, $type_object, $ap_act);
break;
case 'Follow':
ActivityFollow::handle_core_activity($actor, $type_activity, $type_object, $ap_act);
break;
case 'Undo':
$object_type = $type_object instanceof AbstractObject ? match ($type_object->get('type')) {
'Note' => \App\Entity\Note::class,
// no break
default => throw new NotImplementedException('Unsupported Undo of Object Activity.'),
} : $type_object::class;
switch ($object_type) {
case GSActivity::class:
switch ($type_object->getVerb()) {
case 'subscribe':
ActivityFollow::handle_undo($actor, $type_activity, $type_object, $ap_act);
break;
}
break;
}
break;
}
return $ap_act;
}
/**
* Get a JSON
*
* @throws ClientException
*/
public static function toJson(mixed $object, ?int $options = null): string
{
if ($object::class !== GSActivity::class) {
throw new InvalidArgumentException('First argument type must be an Activity.');
}
$gs_verb_to_activity_streams_two_verb = null;
if (Event::handle('GSVerbToActivityStreamsTwoActivityType', [($verb = $object->getVerb()), &$gs_verb_to_activity_streams_two_verb]) === Event::next) {
$gs_verb_to_activity_streams_two_verb = match ($verb) {
'undo' => 'Undo',
'create' => 'Create',
'subscribe' => 'Follow',
default => throw new ClientException('Invalid verb'),
};
}
$attr = [
'type' => $gs_verb_to_activity_streams_two_verb,
'@context' => 'https://www.w3.org/ns/activitystreams',
'id' => Router::url('activity_view', ['id' => $object->getId()], Router::ABSOLUTE_URL),
'published' => $object->getCreated()->format(DateTimeInterface::RFC3339),
'actor' => $object->getActor()->getUri(Router::ABSOLUTE_URL),
];
// Get object or Tombstone
try {
$object = $object->getObject(); // Throws NotFoundException
$attr['object'] = ($attr['type'] === 'Create') ? self::jsonToType(Model::toJson($object)) : ActivityPub::getUriByObject($object);
} catch (NotFoundException) {
// It seems this object was deleted, refer to it as a Tombstone
$uri = match ($object->getObjectType()) {
'note' => Router::url('note_view', ['id' => $object->getObjectId()], type: Router::ABSOLUTE_URL),
'actor' => Router::url('actor_view_id', ['id' => $object->getObjectId()], type: Router::ABSOLUTE_URL),
default => throw new NotImplementedException(),
};
$attr['object'] = Type::create('Tombstone', [
'id' => $uri,
]);
}
// If embedded non tombstone Object
if (!\is_string($attr['object']) && $attr['object']->get('type') !== 'Tombstone') {
// Little special case
if ($attr['type'] === 'Create' && $attr['object']->get('type') === 'Note') {
$attr['to'] = $attr['object']->get('to') ?? [];
$attr['cc'] = $attr['object']->get('cc') ?? [];
}
}
$type = self::jsonToType($attr);
Event::handle('ActivityPubAddActivityStreamsTwoData', [$type->get('type'), &$type]);
return $type->toJson($options);
}
}