src/Protocol/ActivityPub/Receiver.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2023, the Friendica project
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol\ActivityPub;
  23
  24 use Friendica\Content\Text\BBCode;
  25 use Friendica\Database\DBA;
  26 use Friendica\Content\Text\HTML;
  27 use Friendica\Content\Text\Markdown;
  28 use Friendica\Core\Logger;
  29 use Friendica\Core\Protocol;
  30 use Friendica\Core\System;
  31 use Friendica\Core\Worker;
  32 use Friendica\Database\Database;
  33 use Friendica\DI;
  34 use Friendica\Model\Contact;
  35 use Friendica\Model\APContact;
  36 use Friendica\Model\Item;
  37 use Friendica\Model\Post;
  38 use Friendica\Model\User;
  39 use Friendica\Protocol\Activity;
  40 use Friendica\Protocol\ActivityPub;
  41 use Friendica\Util\DateTimeFormat;
  42 use Friendica\Util\HTTPSignature;
  43 use Friendica\Util\JsonLD;
  44 use Friendica\Util\LDSignature;
  45 use Friendica\Util\Network;
  46 use Friendica\Util\Strings;
  47
  48 /**
  49  * ActivityPub Receiver Protocol class
  50  *
  51  * To-Do:
  52  * @todo Undo Announce
  53  *
  54  * Check what this is meant to do:
  55  * - Add
  56  * - Block
  57  * - Flag
  58  * - Remove
  59  * - Undo Block
  60  */
  61 class Receiver
  62 {
  63         const PUBLIC_COLLECTION = 'as:Public';
  64         const ACCOUNT_TYPES = ['as:Person', 'as:Organization', 'as:Service', 'as:Group', 'as:Application'];
  65         const CONTENT_TYPES = ['as:Note', 'as:Article', 'as:Video', 'as:Image', 'as:Event', 'as:Audio', 'as:Page', 'as:Question'];
  66         const ACTIVITY_TYPES = ['as:Like', 'as:Dislike', 'as:Accept', 'as:Reject', 'as:TentativeAccept', 'as:View', 'as:Read', 'litepub:EmojiReact'];
  67
  68         const TARGET_UNKNOWN = 0;
  69         const TARGET_TO = 1;
  70         const TARGET_CC = 2;
  71         const TARGET_BTO = 3;
  72         const TARGET_BCC = 4;
  73         const TARGET_FOLLOWER = 5;
  74         const TARGET_ANSWER = 6;
  75         const TARGET_GLOBAL = 7;
  76         const TARGET_AUDIENCE = 8;
  77
  78         const COMPLETION_NONE     = 0;
  79         const COMPLETION_ANNOUNCE = 1;
  80         const COMPLETION_RELAY    = 2;
  81         const COMPLETION_MANUAL   = 3;
  82         const COMPLETION_AUTO     = 4;
  83         const COMPLETION_ASYNC    = 5;
  84
  85         /**
  86          * Checks incoming message from the inbox
  87          *
  88          * @param string  $body Body string
  89          * @param array   $header Header lines
  90          * @param integer $uid User ID
  91          * @return void
  92          * @throws \Exception
  93          */
  94         public static function processInbox(string $body, array $header, int $uid)
  95         {
  96                 $activity = json_decode($body, true);
  97                 if (empty($activity)) {
  98                         Logger::warning('Invalid body.');
  99                         return;
 100                 }
 101
 102                 $ldactivity = JsonLD::compact($activity);
 103
 104                 $actor = JsonLD::fetchElement($ldactivity, 'as:actor', '@id') ?? '';
 105
 106                 $apcontact = APContact::getByURL($actor);
 107
 108                 if (empty($apcontact)) {
 109                         Logger::notice('Unable to retrieve AP contact for actor - message is discarded', ['actor' => $actor]);
 110                         return;
 111                 } elseif (APContact::isRelay($apcontact) && self::isRelayPost($ldactivity)) {
 112                         self::processRelayPost($ldactivity, $actor);
 113                         return;
 114                 } else {
 115                         APContact::unmarkForArchival($apcontact);
 116                 }
 117
 118                 $sig_contact = HTTPSignature::getKeyIdContact($header);
 119                 if (APContact::isRelay($sig_contact) && self::isRelayPost($ldactivity)) {
 120                         Logger::info('Message from a relay', ['url' => $sig_contact['url']]);
 121                         self::processRelayPost($ldactivity, $sig_contact['url']);
 122                         return;
 123                 }
 124
 125                 $http_signer = HTTPSignature::getSigner($body, $header);
 126                 if ($http_signer === false) {
 127                         Logger::notice('Invalid HTTP signature, message will not be trusted.', ['uid' => $uid, 'actor' => $actor, 'header' => $header, 'body' => $body]);
 128                         $signer = [];
 129                 } elseif (empty($http_signer)) {
 130                         Logger::info('Signer is a tombstone. The message will be discarded, the signer account is deleted.');
 131                         return;
 132                 } else {
 133                         Logger::info('Valid HTTP signature', ['signer' => $http_signer]);
 134                         $signer = [$http_signer];
 135                 }
 136
 137                 Logger::info('Message for user ' . $uid . ' is from actor ' . $actor);
 138
 139                 if ($http_signer === false) {
 140                         $trust_source = false;
 141                 } elseif (LDSignature::isSigned($activity)) {
 142                         $ld_signer = LDSignature::getSigner($activity);
 143                         if (empty($ld_signer)) {
 144                                 Logger::info('Invalid JSON-LD signature from ' . $actor);
 145                         } elseif ($ld_signer != $http_signer) {
 146                                 $signer[] = $ld_signer;
 147                         }
 148                         if (!empty($ld_signer && ($actor == $http_signer))) {
 149                                 Logger::info('The HTTP and the JSON-LD signature belong to ' . $ld_signer);
 150                                 $trust_source = true;
 151                         } elseif (!empty($ld_signer)) {
 152                                 Logger::info('JSON-LD signature is signed by ' . $ld_signer);
 153                                 $trust_source = true;
 154                         } elseif ($actor == $http_signer) {
 155                                 Logger::info('Bad JSON-LD signature, but HTTP signer fits the actor.');
 156                                 $trust_source = true;
 157                         } else {
 158                                 Logger::info('Invalid JSON-LD signature and the HTTP signer is different.');
 159                                 $trust_source = false;
 160                         }
 161                 } elseif ($actor == $http_signer) {
 162                         Logger::info('Trusting post without JSON-LD signature, The actor fits the HTTP signer.');
 163                         $trust_source = true;
 164                 } else {
 165                         Logger::info('No JSON-LD signature, different actor.');
 166                         $trust_source = false;
 167                 }
 168
 169                 self::processActivity($ldactivity, $body, $uid, $trust_source, true, $signer, $http_signer);
 170         }
 171
 172         /**
 173          * Check if the activity is a post rhat can be send via a relay
 174          *
 175          * @param array $activity
 176          * @return boolean
 177          */
 178         private static function isRelayPost(array $activity): bool
 179         {
 180                 $type = JsonLD::fetchElement($activity, '@type');
 181                 if (!$type) {
 182                         return false;
 183                 }
 184
 185                 $object_type = JsonLD::fetchElement($activity, 'as:object', '@type') ?? '';
 186
 187                 $object_id = JsonLD::fetchElement($activity, 'as:object', '@id');
 188                 if (empty($object_id)) {
 189                         return false;
 190                 }
 191
 192                 $handle = ($type == 'as:Announce');
 193
 194                 if (!$handle && in_array($type, ['as:Create', 'as:Update'])) {
 195                         $handle = in_array($object_type, self::CONTENT_TYPES);
 196                 }
 197                 return $handle;
 198         }
 199
 200         /**
 201          * Process incoming posts from relays
 202          *
 203          * @param array  $activity
 204          * @param string $actor
 205          * @return void
 206          */
 207         private static function processRelayPost(array $activity, string $actor)
 208         {
 209                 $type = JsonLD::fetchElement($activity, '@type');
 210                 if (!$type) {
 211                         Logger::notice('Empty type', ['activity' => $activity, 'actor' => $actor]);
 212                         return;
 213                 }
 214
 215                 $object_type = JsonLD::fetchElement($activity, 'as:object', '@type') ?? '';
 216
 217                 $object_id = JsonLD::fetchElement($activity, 'as:object', '@id');
 218                 if (empty($object_id)) {
 219                         Logger::notice('No object id found', ['type' => $type, 'object_type' => $object_type, 'actor' => $actor, 'activity' => $activity]);
 220                         return;
 221                 }
 222
 223                 $contact = Contact::getByURL($actor);
 224                 if (empty($contact)) {
 225                         Logger::info('Relay contact not found', ['actor' => $actor]);
 226                         return;
 227                 }
 228
 229                 if (!in_array($contact['rel'], [Contact::SHARING, Contact::FRIEND])) {
 230                         Logger::notice('Relay is no sharer', ['actor' => $actor]);
 231                         return;
 232                 }
 233
 234                 Logger::debug('Process post from relay server', ['type' => $type, 'object_type' => $object_type, 'object_id' => $object_id, 'actor' => $actor]);
 235
 236                 $item_id = Item::searchByLink($object_id);
 237                 if ($item_id) {
 238                         Logger::info('Relayed message already exists', ['id' => $object_id, 'item' => $item_id, 'actor' => $actor]);
 239                         return;
 240                 }
 241
 242                 if (!DI::config()->get('system', 'decoupled_receiver')) {
 243                         $id = Processor::fetchMissingActivity($object_id, [], $actor, self::COMPLETION_RELAY);
 244                         if (!empty($id)) {
 245                                 Logger::notice('Relayed message is fetched', ['result' => $id, 'id' => $object_id, 'actor' => $actor]);
 246                         } else {
 247                                 Logger::notice('Relayed message had not been fetched', ['id' => $object_id, 'actor' => $actor, 'activity' => $activity]);
 248                         }
 249                 } elseif (!Fetch::hasWorker($object_id)) {
 250                         Logger::notice('Fetching is done by worker.', ['id' => $object_id]);
 251                         Fetch::add($object_id);
 252                         $activity['recursion-depth'] = 0;
 253                         $wid = Worker::add(Worker::PRIORITY_HIGH, 'FetchMissingActivity', $object_id, [], $actor, self::COMPLETION_RELAY);
 254                         Fetch::setWorkerId($object_id, $wid);
 255                 } else {
 256                         Logger::debug('Activity will already be fetched via a worker.', ['url' => $object_id]);
 257                 }
 258         }
 259
 260         /**
 261          * Fetches the object type for a given object id
 262          *
 263          * @param array   $activity
 264          * @param string  $object_id Object ID of the provided object
 265          * @param integer $uid       User ID
 266          *
 267          * @return string with object type or NULL
 268          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 269          * @throws \ImagickException
 270          */
 271         public static function fetchObjectType(array $activity, string $object_id, int $uid = 0)
 272         {
 273                 if (!empty($activity['as:object'])) {
 274                         $object_type = JsonLD::fetchElement($activity['as:object'], '@type');
 275                         if (!empty($object_type)) {
 276                                 return $object_type;
 277                         }
 278                 }
 279
 280                 if (Post::exists(['uri' => $object_id, 'gravity' => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT]])) {
 281                         // We just assume "note" since it doesn't make a difference for the further processing
 282                         return 'as:Note';
 283                 }
 284
 285                 $profile = APContact::getByURL($object_id);
 286                 if (!empty($profile['type'])) {
 287                         APContact::unmarkForArchival($profile);
 288                         return 'as:' . $profile['type'];
 289                 }
 290
 291                 $data = Processor::fetchCachedActivity($object_id, $uid);
 292                 if (!empty($data)) {
 293                         $object = JsonLD::compact($data);
 294                         $type = JsonLD::fetchElement($object, '@type');
 295                         if (!empty($type)) {
 296                                 return $type;
 297                         }
 298                 }
 299
 300                 return null;
 301         }
 302
 303         /**
 304          * Prepare the object array
 305          *
 306          * @param array   $activity       Array with activity data
 307          * @param integer $uid            User ID
 308          * @param boolean $push           Message had been pushed to our system
 309          * @param boolean $trust_source   Do we trust the source?
 310          * @param string  $original_actor Actor of the original activity. Used for receiver detection. (Optional)
 311          * @param string  $http_signer    Actor who has signed the HTTP request
 312          *
 313          * @return array with object data
 314          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 315          * @throws \ImagickException
 316          */
 317         public static function prepareObjectData(array $activity, int $uid, bool $push, bool &$trust_source, string $original_actor = '', string $http_signer = ''): array
 318         {
 319                 $id        = JsonLD::fetchElement($activity, '@id');
 320                 $type      = JsonLD::fetchElement($activity, '@type');
 321                 $object_id = JsonLD::fetchElement($activity, 'as:object', '@id');
 322
 323                 if (!empty($object_id) && in_array($type, ['as:Create', 'as:Update'])) {
 324                         $fetch_id = $object_id;
 325                 } else {
 326                         $fetch_id = $id;
 327                 }
 328
 329                 if (!empty($activity['as:object'])) {
 330                         $object_type = JsonLD::fetchElement($activity['as:object'], '@type');
 331                 }
 332
 333                 $fetched = false;
 334
 335                 if (!empty($id) && !$trust_source) {
 336                         $fetch_uid = $uid ?: self::getBestUserForActivity($activity, $original_actor);
 337
 338                         $fetched_activity = Processor::fetchCachedActivity($fetch_id, $fetch_uid);
 339                         if (!empty($fetched_activity)) {
 340                                 $fetched = true;
 341                                 $object  = JsonLD::compact($fetched_activity);
 342
 343                                 $fetched_id   = JsonLD::fetchElement($object, '@id');
 344                                 $fetched_type = JsonLD::fetchElement($object, '@type');
 345
 346                                 if (($fetched_id == $id) && !empty($fetched_type) && ($fetched_type == $type)) {
 347                                         Logger::info('Activity had been fetched successfully', ['id' => $id]);
 348                                         $trust_source = true;
 349                                         $activity = $object;
 350                                 } elseif (($fetched_id == $object_id) && !empty($fetched_type) && ($fetched_type == $object_type)) {
 351                                         Logger::info('Fetched data is the object instead of the activity', ['id' => $id]);
 352                                         $trust_source = true;
 353                                         unset($object['@context']);
 354                                         $activity['as:object'] = $object;
 355                                 } else {
 356                                         Logger::info('Activity id is not equal', ['id' => $id, 'fetched' => $fetched_id]);
 357                                 }
 358                         } else {
 359                                 Logger::info('Activity could not been fetched', ['id' => $id]);
 360                         }
 361                 }
 362
 363                 $actor = JsonLD::fetchElement($activity, 'as:actor', '@id');
 364                 if (empty($actor)) {
 365                         Logger::info('Empty actor', ['activity' => $activity]);
 366                         return [];
 367                 }
 368
 369                 $type = JsonLD::fetchElement($activity, '@type');
 370
 371                 // Fetch all receivers from to, cc, bto and bcc
 372                 $receiverdata = self::getReceivers($activity, $original_actor ?: $actor, [], false, $push || $fetched, $http_signer);
 373                 $receivers = $reception_types = [];
 374                 foreach ($receiverdata as $key => $data) {
 375                         $receivers[$key] = $data['uid'];
 376                         $reception_types[$data['uid']] = $data['type'] ?? self::TARGET_UNKNOWN;
 377                 }
 378
 379                 $urls = self::getReceiverURL($activity);
 380
 381                 // When it is a delivery to a personal inbox we add that user to the receivers
 382                 if (!empty($uid)) {
 383                         $additional = [$uid => $uid];
 384                         $receivers = array_replace($receivers, $additional);
 385                         if (empty($activity['thread-completion']) && (empty($reception_types[$uid]) || in_array($reception_types[$uid], [self::TARGET_UNKNOWN, self::TARGET_FOLLOWER, self::TARGET_ANSWER, self::TARGET_GLOBAL]))) {
 386                                 $reception_types[$uid] = self::TARGET_BCC;
 387                                 $owner = User::getOwnerDataById($uid);
 388                                 if (!empty($owner['url'])) {
 389                                         $urls['as:bcc'][] = $owner['url'];
 390                                 }
 391                         }
 392                 }
 393
 394                 // We possibly need some user to fetch private content,
 395                 // so we fetch one out of the receivers if no uid is provided.
 396                 $fetch_uid = $uid ?: self::getBestUserForActivity($activity, $original_actor, $http_signer);
 397
 398                 $object_id = JsonLD::fetchElement($activity, 'as:object', '@id');
 399                 if (empty($object_id)) {
 400                         Logger::info('No object found');
 401                         return [];
 402                 }
 403
 404                 if (!is_string($object_id)) {
 405                         Logger::info('Invalid object id', ['object' => $object_id]);
 406                         return [];
 407                 }
 408
 409                 $object_type = self::fetchObjectType($activity, $object_id, $fetch_uid);
 410
 411                 // Any activities on account types must not be altered
 412                 if (in_array($type, ['as:Flag'])) {
 413                         $object_data = [];
 414                         $object_data['id'] = JsonLD::fetchElement($activity, '@id');
 415                         $object_data['object_id'] = JsonLD::fetchElement($activity, 'as:object', '@id');
 416                         $object_data['object_ids'] = JsonLD::fetchElementArray($activity, 'as:object', '@id');
 417                         $object_data['content'] = JsonLD::fetchElement($activity, 'as:content', '@type');
 418                 } elseif (in_array($object_type, self::ACCOUNT_TYPES)) {
 419                         $object_data = [];
 420                         $object_data['id'] = JsonLD::fetchElement($activity, '@id');
 421                         $object_data['object_id'] = JsonLD::fetchElement($activity, 'as:object', '@id');
 422                         $object_data['object_actor'] = JsonLD::fetchElement($activity['as:object'], 'as:actor', '@id');
 423                         $object_data['object_object'] = JsonLD::fetchElement($activity['as:object'], 'as:object');
 424                         $object_data['object_type'] = JsonLD::fetchElement($activity['as:object'], '@type');
 425                         if (!$trust_source && ($type == 'as:Delete')) {
 426                                 $apcontact = APContact::getByURL($object_data['object_id'], true);
 427                                 $trust_source = empty($apcontact) || ($apcontact['type'] == 'Tombstone') || $apcontact['suspended'];
 428                         }
 429                 } elseif (in_array($type, ['as:Create', 'as:Update', 'as:Invite']) || strpos($type, '#emojiReaction')) {
 430                         // Fetch the content only on activities where this matters
 431                         // We can receive "#emojiReaction" when fetching content from Hubzilla systems
 432                         $object_data = self::fetchObject($object_id, $activity['as:object'], $trust_source, $fetch_uid);
 433                         if (empty($object_data)) {
 434                                 Logger::info("Object data couldn't be processed");
 435                                 return [];
 436                         }
 437
 438                         $object_data['object_id'] = $object_id;
 439
 440                         // Test if it is a direct message
 441                         if (self::checkForDirectMessage($object_data, $activity)) {
 442                                 $object_data['directmessage'] = true;
 443                         } elseif (!empty(JsonLD::fetchElement($activity['as:object'], 'misskey:_misskey_talk'))) {
 444                                 $object_data = self::setChatData($object_data, $receivers);
 445                         }
 446                 } elseif (in_array($type, array_merge(self::ACTIVITY_TYPES, ['as:Announce', 'as:Follow'])) && in_array($object_type, self::CONTENT_TYPES)) {
 447                         // Create a mostly empty array out of the activity data (instead of the object).
 448                         // This way we later don't have to check for the existence of each individual array element.
 449                         $object_data = self::processObject($activity, $original_actor);
 450                         $object_data['name'] = $type;
 451                         $object_data['author'] = JsonLD::fetchElement($activity, 'as:actor', '@id');
 452                         $object_data['object_id'] = $object_id;
 453                         $object_data['object_type'] = ''; // Since we don't fetch the object, we don't know the type
 454                 } elseif (in_array($type, ['as:Add', 'as:Remove', 'as:Move'])) {
 455                         $object_data = [];
 456                         $object_data['id'] = JsonLD::fetchElement($activity, '@id');
 457                         $object_data['target_id'] = JsonLD::fetchElement($activity, 'as:target', '@id');
 458                         $object_data['object_id'] = JsonLD::fetchElement($activity, 'as:object', '@id');
 459                         $object_data['object_type'] = JsonLD::fetchElement($activity['as:object'], '@type');
 460                         $object_data['object_content'] = JsonLD::fetchElement($activity['as:object'], 'as:content', '@type');
 461                 } else {
 462                         $object_data = [];
 463                         $object_data['id'] = JsonLD::fetchElement($activity, '@id');
 464                         $object_data['object_id'] = JsonLD::fetchElement($activity, 'as:object', '@id');
 465                         $object_data['object_actor'] = JsonLD::fetchElement($activity['as:object'], 'as:actor', '@id');
 466                         $object_data['object_object'] = JsonLD::fetchElement($activity['as:object'], 'as:object');
 467                         $object_data['object_type'] = JsonLD::fetchElement($activity['as:object'], '@type');
 468
 469                         // An Undo is done on the object of an object, so we need that type as well
 470                         if (($type == 'as:Undo') && !empty($object_data['object_object'])) {
 471                                 $object_data['object_object_type'] = self::fetchObjectType([], $object_data['object_object'], $fetch_uid);
 472                         }
 473
 474                         if (!$trust_source && ($type == 'as:Delete') && in_array($object_data['object_type'], array_merge(['as:Tombstone', ''], self::CONTENT_TYPES))) {
 475                                 $trust_source = Processor::isActivityGone($object_data['object_id']);
 476                                 if (!$trust_source) {
 477                                         $trust_source = !empty(APContact::getByURL($object_data['object_id'], false));
 478                                 }
 479                         }
 480                 }
 481
 482                 $object_data['push'] = $push;
 483
 484                 $object_data = self::addActivityFields($object_data, $activity);
 485
 486                 if (empty($object_data['object_type'])) {
 487                         $object_data['object_type'] = $object_type;
 488                 }
 489
 490                 foreach (['as:to', 'as:cc', 'as:bto', 'as:bcc', 'as:audience', 'as:attributedTo'] as $element) {
 491                         if ((empty($object_data['receiver_urls'][$element]) || in_array($element, ['as:bto', 'as:bcc'])) && !empty($urls[$element])) {
 492                                 $object_data['receiver_urls'][$element] = array_unique(array_merge($object_data['receiver_urls'][$element] ?? [], $urls[$element]));
 493                         }
 494                 }
 495
 496                 $object_data['type'] = $type;
 497                 $object_data['actor'] = $actor;
 498                 $object_data['item_receiver'] = $receivers;
 499                 $object_data['receiver'] = array_replace($object_data['receiver'] ?? [], $receivers);
 500                 $object_data['reception_type'] = array_replace($object_data['reception_type'] ?? [], $reception_types);
 501
 502 //              This check here interferes with Hubzilla posts where the author host differs from the host the post was created
 503 //              $author = $object_data['author'] ?? $actor;
 504 //              if (!empty($author) && !empty($object_data['id'])) {
 505 //                      $author_host = parse_url($author, PHP_URL_HOST);
 506 //                      $id_host = parse_url($object_data['id'], PHP_URL_HOST);
 507 //                      if ($author_host == $id_host) {
 508 //                              Logger::info('Valid hosts', ['type' => $type, 'host' => $id_host]);
 509 //                      } else {
 510 //                              Logger::notice('Differing hosts on author and id', ['type' => $type, 'author' => $author_host, 'id' => $id_host]);
 511 //                              $trust_source = false;
 512 //                      }
 513 //              }
 514
 515                 $account = Contact::selectFirstAccount(['platform'], ['nurl' => Strings::normaliseLink($actor)]);
 516                 $platform = $account['platform'] ?? '';
 517
 518                 Logger::info('Processing', ['type' => $object_data['type'], 'object_type' => $object_data['object_type'], 'id' => $object_data['id'], 'actor' => $actor, 'platform' => $platform]);
 519
 520                 return $object_data;
 521         }
 522
 523         /**
 524          * Check if the received message is a direct message
 525          *
 526          * @param array $object_data
 527          * @param array $activity
 528          * @return boolean
 529          */
 530         private static function checkForDirectMessage(array $object_data, array $activity): bool
 531         {
 532                 if (DBA::exists('mail', ['uri' => $object_data['reply-to-id']])) {
 533                         return true;
 534                 }
 535
 536                 if ($object_data['id'] != $object_data['reply-to-id']) {
 537                         return false;
 538                 }
 539
 540                 if (JsonLD::fetchElement($activity, 'litepub:directMessage')) {
 541                         return true;
 542                 }
 543
 544                 if (!empty($object_data['attachments'])) {
 545                         return false;
 546                 }
 547
 548                 if (!empty($object_data['receiver_urls']['as:cc']) || empty($object_data['receiver_urls']['as:to'])) {
 549                         return false;
 550                 }
 551
 552                 if ((count($object_data['receiver_urls']['as:to']) != 1) || !User::getIdForURL($object_data['receiver_urls']['as:to'][0])) {
 553                         return false;
 554                 }
 555
 556                 $mentions = 0;
 557                 foreach ($object_data['tags'] as $mention) {
 558                         if ($mention['type'] != 'Mention') {
 559                                 continue;
 560                         }
 561                         if (!User::getIdForURL($mention['href'])) {
 562                                 return false;
 563                         }
 564                         ++$mentions;
 565                 }
 566
 567                 if ($mentions > 1) {
 568                         return false;
 569                 }
 570
 571                 return true;
 572         }
 573
 574         private static function setChatData(array $object_data, array $receivers): array
 575         {
 576                 if (count($receivers) != 1) {
 577                         return $object_data;
 578                 }
 579
 580                 $user = User::getById(array_key_first($receivers), ['language']);
 581                 $l10n = DI::l10n()->withLang($user['language']);
 582                 $object_data['name'] = $l10n->t('Chat');
 583
 584                 $mail = DBA::selectFirst('mail', ['uri'], ['uid' => array_key_first($receivers), 'title' => $object_data['name']], ['order' => ['id' => true]]);
 585                 if (!empty($mail['uri'])) {
 586                         $object_data['reply-to-id'] = $mail['uri'];
 587                 }
 588
 589                 $object_data['directmessage'] = true;
 590                 Logger::debug('Got Misskey Chat');
 591                 return $object_data;
 592         }
 593
 594         /**
 595          * Fetches the first user id from the receiver array
 596          *
 597          * @param array $receivers Array with receivers
 598          * @return integer user id;
 599          */
 600         public static function getFirstUserFromReceivers(array $receivers): int
 601         {
 602                 foreach ($receivers as $receiver) {
 603                         if (!empty($receiver)) {
 604                                 return $receiver;
 605                         }
 606                 }
 607                 return 0;
 608         }
 609
 610         /**
 611          * Processes the activity object
 612          *
 613          * @param array      $activity     Array with activity data
 614          * @param string     $body         The unprocessed body
 615          * @param int|null   $uid          User ID
 616          * @param boolean    $trust_source Do we trust the source?
 617          * @param boolean    $push         Message had been pushed to our system
 618          * @param array      $signer       The signer of the post
 619          *
 620          * @return bool
 621          *
 622          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 623          * @throws \ImagickException
 624          */
 625         public static function processActivity(array $activity, string $body = '', int $uid = null, bool $trust_source = false, bool $push = false, array $signer = [], string $http_signer = '', int $completion = Receiver::COMPLETION_AUTO): bool
 626         {
 627                 $type = JsonLD::fetchElement($activity, '@type');
 628                 if (!$type) {
 629                         Logger::info('Empty type', ['activity' => $activity]);
 630                         return true;
 631                 }
 632
 633                 if (!DI::config()->get('system', 'process_view') && ($type == 'as:View')) {
 634                         Logger::info('View activities are ignored.', ['signer' => $signer, 'http_signer' => $http_signer]);
 635                         return true;
 636                 }
 637
 638                 if (!JsonLD::fetchElement($activity, 'as:object', '@id')) {
 639                         Logger::info('Empty object', ['activity' => $activity]);
 640                         return true;
 641                 }
 642
 643                 $actor = JsonLD::fetchElement($activity, 'as:actor', '@id');
 644                 if (empty($actor)) {
 645                         Logger::info('Empty actor', ['activity' => $activity]);
 646                         return true;
 647                 }
 648
 649                 if (is_array($activity['as:object'])) {
 650                         $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
 651                 } else {
 652                         $attributed_to = '';
 653                 }
 654
 655                 // Test the provided signatures against the actor and "attributedTo"
 656                 if ($trust_source) {
 657                         if (!empty($attributed_to) && !empty($actor)) {
 658                                 $trust_source = (in_array($actor, $signer) && in_array($attributed_to, $signer));
 659                         } else {
 660                                 $trust_source = in_array($actor, $signer);
 661                         }
 662                 }
 663
 664                 // Lemmy announces activities.
 665                 // To simplify the further processing, we modify the received object.
 666                 // For announced "create" activities we remove the middle layer.
 667                 // For the rest (like, dislike, update, ...) we just process the activity directly.
 668                 $original_actor = '';
 669                 $object_type = JsonLD::fetchElement($activity['as:object'] ?? [], '@type');
 670                 if (($type == 'as:Announce') && !empty($object_type) && !in_array($object_type, self::CONTENT_TYPES) && self::isGroup($actor)) {
 671                         $object_object_type = JsonLD::fetchElement($activity['as:object']['as:object'] ?? [], '@type');
 672                         if (in_array($object_type, ['as:Create']) && in_array($object_object_type, self::CONTENT_TYPES)) {
 673                                 Logger::debug('Replace "create" activity with inner object', ['type' => $object_type, 'object_type' => $object_object_type]);
 674                                 $activity['as:object'] = $activity['as:object']['as:object'];
 675                         } elseif (in_array($object_type, array_merge(self::ACTIVITY_TYPES, ['as:Delete', 'as:Undo', 'as:Update']))) {
 676                                 Logger::debug('Change announced activity to activity', ['type' => $object_type]);
 677                                 $original_actor = $actor;
 678                                 $type = $object_type;
 679                                 $activity = $activity['as:object'];
 680                         } else {
 681                                 Logger::info('Unhandled announced activity', ['type' => $object_type, 'object_type' => $object_object_type]);
 682                         }
 683                 }
 684
 685                 // $trust_source is called by reference and is set to true if the content was retrieved successfully
 686                 $object_data = self::prepareObjectData($activity, $uid, $push, $trust_source, $original_actor, $trust_source ? $http_signer : '');
 687                 if (empty($object_data)) {
 688                         Logger::info('No object data found', ['activity' => $activity]);
 689                         return true;
 690                 }
 691
 692                 if (!empty($body) && empty($object_data['raw'])) {
 693                         $object_data['raw'] = $body;
 694                 }
 695
 696                 // Internal flag for thread completion. See Processor.php
 697                 if (!empty($activity['thread-completion'])) {
 698                         $object_data['thread-completion'] = $activity['thread-completion'];
 699                 }
 700
 701                 if (!empty($activity['completion-mode'])) {
 702                         $object_data['completion-mode'] = $activity['completion-mode'];
 703                 }
 704
 705                 if (!empty($activity['thread-children-type'])) {
 706                         $object_data['thread-children-type'] = $activity['thread-children-type'];
 707                 }
 708
 709                 // Internal flag for posts that arrived via relay
 710                 if (!empty($activity['from-relay'])) {
 711                         $object_data['from-relay'] = $activity['from-relay'];
 712                 }
 713
 714                 if ($type == 'as:Announce') {
 715                         $object_data['object_activity'] = $activity;
 716                 }
 717
 718                 if (($type == 'as:Create') && $trust_source && !in_array($completion, [self::COMPLETION_MANUAL, self::COMPLETION_ANNOUNCE])) {
 719                         if (self::hasArrived($object_data['object_id'])) {
 720                                 Logger::info('The activity already arrived.', ['id' => $object_data['object_id']]);
 721                                 return true;
 722                         }
 723                         self::addArrivedId($object_data['object_id']);
 724
 725                         if (Queue::exists($object_data['object_id'], $type)) {
 726                                 Logger::info('The activity is already added.', ['id' => $object_data['object_id']]);
 727                                 return true;
 728                         }
 729                 } elseif (($type == 'as:Create') && $trust_source && !self::hasArrived($object_data['object_id'])) {
 730                         self::addArrivedId($object_data['object_id']);
 731                 }
 732
 733                 $decouple = DI::config()->get('system', 'decoupled_receiver') && !in_array($completion, [self::COMPLETION_MANUAL, self::COMPLETION_ANNOUNCE]) && empty($object_data['directmessage']);
 734
 735                 if ($decouple && ($trust_source || DI::config()->get('debug', 'ap_inbox_store_untrusted'))) {
 736                         $object_data = Queue::add($object_data, $type, $uid, $http_signer, $push, $trust_source);
 737                 }
 738
 739                 if (!$trust_source) {
 740                         Logger::info('Activity trust could not be achieved.',  ['id' => $object_data['object_id'], 'type' => $type, 'signer' => $signer, 'actor' => $actor, 'attributedTo' => $attributed_to]);
 741                         return true;
 742                 }
 743
 744                 if (!empty($object_data['entry-id']) && $decouple && ($push || in_array($completion, [self::COMPLETION_RELAY, self::COMPLETION_ASYNC]))) {
 745                         if (Queue::isProcessable($object_data['entry-id'])) {
 746                                 // We delay by 5 seconds to allow to accumulate all receivers
 747                                 $delayed = date(DateTimeFormat::MYSQL, time() + 5);
 748                                 Logger::debug('Initiate processing', ['id' => $object_data['entry-id'], 'uri' => $object_data['object_id']]);
 749                                 $wid = Worker::add(['priority' => Worker::PRIORITY_HIGH, 'delayed' => $delayed], 'ProcessQueue', $object_data['entry-id']);
 750                                 Queue::setWorkerId($object_data['entry-id'], $wid);
 751                         } else {
 752                                 Logger::debug('Other queue entries need to be processed first.', ['id' => $object_data['entry-id']]);
 753                         }
 754                         return false;
 755                 }
 756
 757                 if (!empty($activity['recursion-depth'])) {
 758                         $object_data['recursion-depth'] = $activity['recursion-depth'];
 759                 }
 760
 761                 if (!self::routeActivities($object_data, $type, $push, true, $uid)) {
 762                         self::storeUnhandledActivity(true, $type, $object_data, $activity, $body, $uid, $trust_source, $push, $signer);
 763                         Queue::remove($object_data);
 764                 }
 765                 return true;
 766         }
 767
 768         /**
 769          * Checks if the provided actor is a group account
 770          *
 771          * @param string $actor
 772          * @return boolean
 773          */
 774         private static function isGroup(string $actor): bool
 775         {
 776                 $profile = APContact::getByURL($actor);
 777                 return ($profile['type'] ?? '') == 'Group';
 778         }
 779
 780         /**
 781          * Route activities
 782          *
 783          * @param array  $object_data
 784          * @param string $type
 785          * @param bool   $push
 786          * @param bool   $fetch_parents
 787          * @param int    $uid
 788          *
 789          * @return boolean Could the activity be routed?
 790          */
 791         public static function routeActivities(array $object_data, string $type, bool $push, bool $fetch_parents = true, int $uid = 0): bool
 792         {
 793                 switch ($type) {
 794                         case 'as:Create':
 795                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 796                                         $item = ActivityPub\Processor::createItem($object_data, $fetch_parents);
 797                                         ActivityPub\Processor::postItem($object_data, $item);
 798                                 } elseif (in_array($object_data['object_type'], ['pt:CacheFile'])) {
 799                                         // Unhandled Peertube activity
 800                                         Queue::remove($object_data);
 801                                 } elseif (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 802                                         ActivityPub\Processor::updatePerson($object_data);
 803                                 } else {
 804                                         return false;
 805                                 }
 806                                 break;
 807
 808                         case 'as:Invite':
 809                                 if (in_array($object_data['object_type'], ['as:Event'])) {
 810                                         $item = ActivityPub\Processor::createItem($object_data, $fetch_parents);
 811                                         ActivityPub\Processor::postItem($object_data, $item);
 812                                 } else {
 813                                         return false;
 814                                 }
 815                                 break;
 816
 817                         case 'as:Add':
 818                                 if ($object_data['object_type'] == 'as:tag') {
 819                                         ActivityPub\Processor::addTag($object_data);
 820                                 } elseif (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 821                                         ActivityPub\Processor::addToFeaturedCollection($object_data);
 822                                 } elseif (in_array($object_data['object_type'], ['as:Tombstone', ''])) {
 823                                         // We don't have the object here or it is deleted. We ignore this activity.
 824                                         Queue::remove($object_data);
 825                                 } else {
 826                                         return false;
 827                                 }
 828                                 break;
 829
 830                         case 'as:Announce':
 831                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 832                                         if (!Item::searchByLink($object_data['object_id'], $uid)) {
 833                                                 if (ActivityPub\Processor::fetchMissingActivity($object_data['object_id'], [], $object_data['actor'], self::COMPLETION_ANNOUNCE, $uid)) {
 834                                                         Logger::debug('Created announced id', ['uid' => $uid, 'id' => $object_data['object_id']]);
 835                                                         Queue::remove($object_data);
 836                                                 } else {
 837                                                         Logger::debug('Announced id was not created', ['uid' => $uid, 'id' => $object_data['object_id']]);
 838                                                         Queue::remove($object_data);
 839                                                         return true;
 840                                                 }
 841                                         } else {
 842                                                 Logger::info('Announced id already exists', ['uid' => $uid, 'id' => $object_data['object_id']]);
 843                                                 Queue::remove($object_data);
 844                                         }
 845
 846                                         ActivityPub\Processor::createActivity($object_data, Activity::ANNOUNCE);
 847                                 } elseif (in_array($object_data['object_type'], ['as:Tombstone', ''])) {
 848                                         // We don't have the object here or it is deleted. We ignore this activity.
 849                                         Queue::remove($object_data);
 850                                 } else {
 851                                         return false;
 852                                 }
 853                                 break;
 854
 855                         case 'as:Like':
 856                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 857                                         ActivityPub\Processor::createActivity($object_data, Activity::LIKE);
 858                                 } elseif (in_array($object_data['object_type'], ['as:Tombstone', ''])) {
 859                                         // We don't have the object here or it is deleted. We ignore this activity.
 860                                         Queue::remove($object_data);
 861                                 } else {
 862                                         return false;
 863                                 }
 864                                 break;
 865
 866                         case 'as:Dislike':
 867                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 868                                         ActivityPub\Processor::createActivity($object_data, Activity::DISLIKE);
 869                                 } elseif (in_array($object_data['object_type'], ['as:Tombstone', ''])) {
 870                                         // We don't have the object here or it is deleted. We ignore this activity.
 871                                         Queue::remove($object_data);
 872                                 } else {
 873                                         return false;
 874                                 }
 875                                 break;
 876
 877                         case 'as:TentativeAccept':
 878                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 879                                         ActivityPub\Processor::createActivity($object_data, Activity::ATTENDMAYBE);
 880                                 } else {
 881                                         return false;
 882                                 }
 883                                 break;
 884
 885                         case 'as:Update':
 886                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 887                                         ActivityPub\Processor::updateItem($object_data);
 888                                 } elseif (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 889                                         ActivityPub\Processor::updatePerson($object_data);
 890                                 } elseif (in_array($object_data['object_type'], ['pt:CacheFile'])) {
 891                                         // Unhandled Peertube activity
 892                                         Queue::remove($object_data);
 893                                 } else {
 894                                         return false;
 895                                 }
 896                                 break;
 897
 898                         case 'as:Delete':
 899                                 if (in_array($object_data['object_type'], array_merge(['as:Tombstone'], self::CONTENT_TYPES))) {
 900                                         ActivityPub\Processor::deleteItem($object_data);
 901                                 } elseif (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 902                                         ActivityPub\Processor::deletePerson($object_data);
 903                                 } elseif ($object_data['object_type'] == '') {
 904                                         // The object type couldn't be determined. Most likely we don't have it here. We ignore this activity.
 905                                         Queue::remove($object_data);
 906                                 } else {
 907                                         return false;
 908                                 }
 909                                 break;
 910
 911                         case 'as:Move':
 912                                 if (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 913                                         ActivityPub\Processor::movePerson($object_data);
 914                                 } else {
 915                                         return false;
 916                                 }
 917                                 break;
 918
 919                         case 'as:Block':
 920                                 if (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 921                                         ActivityPub\Processor::blockAccount($object_data);
 922                                 } else {
 923                                         return false;
 924                                 }
 925                                 break;
 926
 927                         case 'as:Flag':
 928                                 if (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 929                                         ActivityPub\Processor::ReportAccount($object_data);
 930                                 } else {
 931                                         return false;
 932                                 }
 933                                 break;
 934
 935                         case 'as:Remove':
 936                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 937                                         ActivityPub\Processor::removeFromFeaturedCollection($object_data);
 938                                 } elseif (in_array($object_data['object_type'], ['as:Tombstone', ''])) {
 939                                         // We don't have the object here or it is deleted. We ignore this activity.
 940                                         Queue::remove($object_data);
 941                                 } else {
 942                                         return false;
 943                                 }
 944                                 break;
 945
 946                         case 'as:Follow':
 947                                 if (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 948                                         ActivityPub\Processor::followUser($object_data);
 949                                 } elseif (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 950                                         $object_data['reply-to-id'] = $object_data['object_id'];
 951                                         ActivityPub\Processor::createActivity($object_data, Activity::FOLLOW);
 952                                 } else {
 953                                         return false;
 954                                 }
 955                                 break;
 956
 957                         case 'as:Accept':
 958                                 if ($object_data['object_type'] == 'as:Follow') {
 959                                         if (!empty($object_data['object_actor'])) {
 960                                                 ActivityPub\Processor::acceptFollowUser($object_data);
 961                                         } else {
 962                                                 Logger::notice('Unhandled "accept follow" message.', ['object_data' => $object_data]);
 963                                         }
 964                                 } elseif (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 965                                         ActivityPub\Processor::createActivity($object_data, Activity::ATTEND);
 966                                 } elseif (!empty($object_data['object_id']) && empty($object_data['object_actor']) && empty($object_data['object_type'])) {
 967                                         // Follow acceptances from gup.pe only contain the object id
 968                                         ActivityPub\Processor::acceptFollowUser($object_data);
 969                                 } else {
 970                                         return false;
 971                                 }
 972                                 break;
 973
 974                         case 'as:Reject':
 975                                 if ($object_data['object_type'] == 'as:Follow') {
 976                                         ActivityPub\Processor::rejectFollowUser($object_data);
 977                                 } elseif (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 978                                         ActivityPub\Processor::createActivity($object_data, Activity::ATTENDNO);
 979                                 } else {
 980                                         return false;
 981                                 }
 982                                 break;
 983
 984                         case 'as:Undo':
 985                                 if (($object_data['object_type'] == 'as:Follow') &&
 986                                         in_array($object_data['object_object_type'], self::ACCOUNT_TYPES)) {
 987                                         ActivityPub\Processor::undoFollowUser($object_data);
 988                                 } elseif (($object_data['object_type'] == 'as:Follow') &&
 989                                         in_array($object_data['object_object_type'], self::CONTENT_TYPES)) {
 990                                         ActivityPub\Processor::undoActivity($object_data);
 991                                 } elseif (($object_data['object_type'] == 'as:Accept') &&
 992                                         in_array($object_data['object_object_type'], self::ACCOUNT_TYPES)) {
 993                                         ActivityPub\Processor::rejectFollowUser($object_data);
 994                                 } elseif (($object_data['object_type'] == 'as:Block') &&
 995                                         in_array($object_data['object_object_type'], self::ACCOUNT_TYPES)) {
 996                                         ActivityPub\Processor::unblockAccount($object_data);
 997                                 } elseif (in_array($object_data['object_type'], array_merge(self::ACTIVITY_TYPES, ['as:Announce', 'as:Create', ''])) &&
 998                                         empty($object_data['object_object_type'])) {
 999                                         // We cannot detect the target object. So we can ignore it.
1000                                         Queue::remove($object_data);
1001                                 } elseif (in_array($object_data['object_type'], array_merge(self::ACTIVITY_TYPES, ['as:Announce'])) &&
1002                                         in_array($object_data['object_object_type'], array_merge(['as:Tombstone'], self::CONTENT_TYPES))) {
1003                                         ActivityPub\Processor::undoActivity($object_data);
1004                                 } elseif (in_array($object_data['object_type'], ['as:Create']) &&
1005                                         in_array($object_data['object_object_type'], ['pt:CacheFile'])) {
1006                                         // Unhandled Peertube activity
1007                                         Queue::remove($object_data);
1008                                 } elseif (in_array($object_data['object_type'], ['as:Delete'])) {
1009                                         // We cannot undo deletions, so we just ignore this
1010                                         Queue::remove($object_data);
1011                                 } elseif (in_array($object_data['object_object_type'], ['as:Tombstone'])) {
1012                                         // The object is a tombstone, we ignore any actions on it.
1013                                         Queue::remove($object_data);
1014                                 } else {
1015                                         return false;
1016                                 }
1017                                 break;
1018
1019                         case 'as:View':
1020                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
1021                                         ActivityPub\Processor::createActivity($object_data, Activity::VIEW);
1022                                 } elseif (in_array($object_data['object_type'], ['as:Tombstone', ''])) {
1023                                         // We don't have the object here or it is deleted. We ignore this activity.
1024                                         Queue::remove($object_data);
1025                                 } else {
1026                                         return false;
1027                                 }
1028                                 break;
1029                         case 'as:Read':
1030                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
1031                                         ActivityPub\Processor::createActivity($object_data, Activity::READ);
1032                                 } elseif (in_array($object_data['object_type'], ['as:Tombstone', ''])) {
1033                                         // We don't have the object here or it is deleted. We ignore this activity.
1034                                         Queue::remove($object_data);
1035                                 } else {
1036                                         return false;
1037                                 }
1038                                 break;
1039
1040                         case 'litepub:EmojiReact':
1041                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
1042                                         ActivityPub\Processor::createActivity($object_data, Activity::EMOJIREACT);
1043                                 } elseif (in_array($object_data['object_type'], ['as:Tombstone', ''])) {
1044                                         // We don't have the object here or it is deleted. We ignore this activity.
1045                                         Queue::remove($object_data);
1046                                 } else {
1047                                         return false;
1048                                 }
1049                                 break;
1050
1051                         default:
1052                                 Logger::info('Unknown activity: ' . $type . ' ' . $object_data['object_type']);
1053                                 return false;
1054                 }
1055                 return true;
1056         }
1057
1058         /**
1059          * Stores unhandled or unknown Activities as a file
1060          *
1061          * @param boolean $unknown      "true" if the activity is unknown, "false" if it is unhandled
1062          * @param string  $type         Activity type
1063          * @param array   $object_data  Preprocessed array that is generated out of the received activity
1064          * @param array   $activity     Array with activity data
1065          * @param string  $body         The unprocessed body
1066          * @param integer $uid          User ID
1067          * @param boolean $trust_source Do we trust the source?
1068          * @param boolean $push         Message had been pushed to our system
1069          * @param array   $signer       The signer of the post
1070          * @return void
1071          */
1072         private static function storeUnhandledActivity(bool $unknown, string $type, array $object_data, array $activity, string $body = '', int $uid = null, bool $trust_source = false, bool $push = false, array $signer = [])
1073         {
1074                 if (!DI::config()->get('debug', 'ap_log_unknown')) {
1075                         return;
1076                 }
1077
1078                 $file = ($unknown  ? 'unknown-' : 'unhandled-') . str_replace(':', '-', $type) . '-';
1079
1080                 if (!empty($object_data['object_type'])) {
1081                         $file .= str_replace(':', '-', $object_data['object_type']) . '-';
1082                 }
1083
1084                 if (!empty($object_data['object_object_type'])) {
1085                         $file .= str_replace(':', '-', $object_data['object_object_type']) . '-';
1086                 }
1087
1088                 $tempfile = tempnam(System::getTempPath(), $file);
1089                 file_put_contents($tempfile, json_encode(['activity' => $activity, 'body' => $body, 'uid' => $uid, 'trust_source' => $trust_source, 'push' => $push, 'signer' => $signer, 'object_data' => $object_data], JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT));
1090                 Logger::notice('Unknown activity stored', ['type' => $type, 'object_type' => $object_data['object_type'], 'object_object_type' => $object_data['object_object_type'] ?? '', 'file' => $tempfile]);
1091         }
1092
1093         /**
1094          * Fetch a user id from an activity array
1095          *
1096          * @param array  $activity
1097          * @param string $actor
1098          * @param string $http_signer
1099          *
1100          * @return int   user id
1101          */
1102         private static function getBestUserForActivity(array $activity, string $actor, string $http_signer = ''): int
1103         {
1104                 $uid = 0;
1105                 $actor = $actor ?: JsonLD::fetchElement($activity, 'as:actor', '@id') ?? '';
1106
1107                 $receivers = self::getReceivers($activity, $actor, [], false, false, $http_signer);
1108                 foreach ($receivers as $receiver) {
1109                         if ($receiver['type'] == self::TARGET_GLOBAL) {
1110                                 return 0;
1111                         }
1112                         if (empty($uid) || ($receiver['type'] == self::TARGET_TO)) {
1113                                 $uid = $receiver['uid'];
1114                         }
1115                 }
1116
1117                 // When we haven't found any user yet, we just chose a user who most likely could have access to the content
1118                 if (empty($uid)) {
1119                         $contact = Contact::selectFirst(['uid'], ['nurl' => Strings::normaliseLink($actor), 'rel' => [Contact::SHARING, Contact::FRIEND]]);
1120                         if (!empty($contact['uid'])) {
1121                                 $uid = $contact['uid'];
1122                         }
1123                 }
1124
1125                 return $uid;
1126         }
1127
1128         // @TODO Missing documentation
1129         public static function getReceiverURL(array $activity): array
1130         {
1131                 $urls = [];
1132
1133                 foreach (['as:to', 'as:cc', 'as:bto', 'as:bcc', 'as:audience', 'as:attributedTo'] as $element) {
1134                         $receiver_list = JsonLD::fetchElementArray($activity, $element, '@id');
1135                         if (empty($receiver_list)) {
1136                                 continue;
1137                         }
1138
1139                         foreach ($receiver_list as $receiver) {
1140                                 if ($receiver == 'Public') {
1141                                         Logger::warning('Not compacted public collection found', ['activity' => $activity]);
1142                                         $receiver = ActivityPub::PUBLIC_COLLECTION;
1143                                 }
1144                                 if ($receiver == self::PUBLIC_COLLECTION) {
1145                                         $receiver = ActivityPub::PUBLIC_COLLECTION;
1146                                 }
1147                                 $urls[$element][] = $receiver;
1148                         }
1149                 }
1150
1151                 return $urls;
1152         }
1153
1154         /**
1155          * Fetch the receiver list from an activity array
1156          *
1157          * @param array   $activity
1158          * @param string $actor
1159          * @param array  $tags
1160          * @param bool   $fetch_unlisted
1161          * @param bool   $push
1162          * @param string $http_signer
1163          *
1164          * @return array with receivers (user id)
1165          * @throws \Exception
1166          */
1167         private static function getReceivers(array $activity, string $actor, array $tags, bool $fetch_unlisted, bool $push, string $http_signer = ''): array
1168         {
1169                 $reply = $receivers = $profile = [];
1170
1171                 // When it is an answer, we inherit the receivers from the parent
1172                 $replyto = JsonLD::fetchElement($activity, 'as:inReplyTo', '@id');
1173                 if (!empty($replyto)) {
1174                         $reply = [$replyto];
1175
1176                         // Fix possibly wrong item URI (could be an answer to a plink uri)
1177                         $fixedReplyTo = Item::getURIByLink($replyto);
1178                         if (!empty($fixedReplyTo)) {
1179                                 $reply[] = $fixedReplyTo;
1180                         }
1181                 }
1182
1183                 // Fetch all posts that refer to the object id
1184                 $object_id = JsonLD::fetchElement($activity, 'as:object', '@id');
1185                 if (!empty($object_id)) {
1186                         $reply[] = $object_id;
1187                 }
1188
1189                 if (!empty($actor)) {
1190                         $profile   = APContact::getByURL($actor);
1191                         $followers = $profile['followers'] ?? '';
1192                         $isGroup  = ($profile['type'] ?? '') == 'Group';
1193                         if ($push) {
1194                                 Contact::updateByUrlIfNeeded($actor);
1195                         }
1196                         Logger::info('Got actor and followers', ['actor' => $actor, 'followers' => $followers]);
1197                 } else {
1198                         Logger::info('Empty actor', ['activity' => $activity]);
1199                         $followers = '';
1200                         $isGroup  = false;
1201                 }
1202
1203                 // We have to prevent false follower assumptions upon thread completions
1204                 $follower_target = empty($activity['thread-completion']) ? self::TARGET_FOLLOWER : self::TARGET_UNKNOWN;
1205
1206                 if (($actor != $http_signer) && ($http_signer != '') && ($follower_target == self::TARGET_FOLLOWER)) {
1207                         $signer_profile   = APContact::getByURL($http_signer);
1208                         $signer_followers = $signer_profile['followers'] ?? '';
1209                 } else {
1210                         $signer_followers = '';
1211                 }
1212
1213                 foreach (['as:to', 'as:cc', 'as:bto', 'as:bcc','as:audience'] as $element) {
1214                         $receiver_list = JsonLD::fetchElementArray($activity, $element, '@id');
1215                         if (empty($receiver_list)) {
1216                                 continue;
1217                         }
1218
1219                         foreach ($receiver_list as $receiver) {
1220                                 if ($receiver == self::PUBLIC_COLLECTION) {
1221                                         $receivers[0] = ['uid' => 0, 'type' => self::TARGET_GLOBAL];
1222                                 }
1223
1224                                 // Add receiver "-1" for unlisted posts
1225                                 if ($fetch_unlisted && ($receiver == self::PUBLIC_COLLECTION) && ($element == 'as:cc')) {
1226                                         $receivers[-1] = ['uid' => -1, 'type' => self::TARGET_GLOBAL];
1227                                 }
1228
1229                                 // Fetch the receivers for the public and the followers collection
1230                                 if ((($receiver == $followers) || (($receiver == self::PUBLIC_COLLECTION) && !$isGroup) || ($isGroup && ($element == 'as:audience'))) && !empty($actor)) {
1231                                         $receivers = self::getReceiverForActor($actor, $tags, $receivers, $follower_target, $profile);
1232                                         continue;
1233                                 }
1234
1235                                 if ($receiver == $signer_followers) {
1236                                         $receivers = self::getReceiverForActor($http_signer, [], $receivers, $follower_target, $signer_profile);
1237                                         continue;
1238                                 }
1239
1240                                 // Fetching all directly addressed receivers
1241                                 $condition = ['self' => true, 'nurl' => Strings::normaliseLink($receiver)];
1242                                 $contact = DBA::selectFirst('contact', ['uid', 'contact-type'], $condition);
1243                                 if (!DBA::isResult($contact)) {
1244                                         continue;
1245                                 }
1246
1247                                 // Check if the potential receiver is following the actor
1248                                 // Exception: The receiver is targetted via "to" or this is a comment
1249                                 if ((($element != 'as:to') && empty($replyto)) || ($contact['contact-type'] == Contact::TYPE_COMMUNITY)) {
1250                                         $networks = Protocol::FEDERATED;
1251                                         $condition = ['nurl' => Strings::normaliseLink($actor), 'rel' => [Contact::SHARING, Contact::FRIEND],
1252                                                 'network' => $networks, 'archive' => false, 'pending' => false, 'uid' => $contact['uid']];
1253
1254                                         // Group posts are only accepted from group contacts
1255                                         if ($contact['contact-type'] == Contact::TYPE_COMMUNITY) {
1256                                                 $condition['rel'] = [Contact::SHARING, Contact::FRIEND, Contact::FOLLOWER];
1257                                         }
1258
1259                                         if (!DBA::exists('contact', $condition)) {
1260                                                 continue;
1261                                         }
1262                                 }
1263
1264                                 $type = $receivers[$contact['uid']]['type'] ?? self::TARGET_UNKNOWN;
1265                                 if (in_array($type, [self::TARGET_UNKNOWN, self::TARGET_FOLLOWER, self::TARGET_ANSWER, self::TARGET_GLOBAL])) {
1266                                         switch ($element) {
1267                                                 case 'as:to':
1268                                                         $type = self::TARGET_TO;
1269                                                         break;
1270                                                 case 'as:cc':
1271                                                         $type = self::TARGET_CC;
1272                                                         break;
1273                                                 case 'as:bto':
1274                                                         $type = self::TARGET_BTO;
1275                                                         break;
1276                                                 case 'as:bcc':
1277                                                         $type = self::TARGET_BCC;
1278                                                         break;
1279                                                 case 'as:audience':
1280                                                         $type = self::TARGET_AUDIENCE;
1281                                                         break;
1282                                         }
1283
1284                                         $receivers[$contact['uid']] = ['uid' => $contact['uid'], 'type' => $type];
1285                                 }
1286                         }
1287                 }
1288
1289                 if (!empty($reply) && (!empty($receivers[0]) || !empty($receivers[-1]))) {
1290                         $parents = Post::select(['uid'], DBA::mergeConditions(['uri' => $reply], ["`uid` != ?", 0]));
1291                         while ($parent = Post::fetch($parents)) {
1292                                 $receivers[$parent['uid']] = ['uid' => $parent['uid'], 'type' => self::TARGET_ANSWER];
1293                         }
1294                         DBA::close($parents);
1295                 }
1296
1297                 self::switchContacts($receivers, $actor);
1298
1299                 // "birdsitelive" is a service that mirrors tweets into the fediverse
1300                 // These posts can be fetched without authentication, but are not marked as public
1301                 // We treat them as unlisted posts to be able to handle them.
1302                 // We always process deletion activities.
1303                 $activity_type = JsonLD::fetchElement($activity, '@type');
1304                 if (empty($receivers) && $fetch_unlisted && Contact::isPlatform($actor, 'birdsitelive')) {
1305                         $receivers[0]  = ['uid' => 0, 'type' => self::TARGET_GLOBAL];
1306                         $receivers[-1] = ['uid' => -1, 'type' => self::TARGET_GLOBAL];
1307                         Logger::notice('Post from "birdsitelive" is set to "unlisted"', ['id' => JsonLD::fetchElement($activity, '@id')]);
1308                 } elseif (empty($receivers) && in_array($activity_type, ['as:Delete', 'as:Undo'])) {
1309                         $receivers[0] = ['uid' => 0, 'type' => self::TARGET_GLOBAL];
1310                 } elseif (empty($receivers)) {
1311                         Logger::notice('Post has got no receivers', ['fetch_unlisted' => $fetch_unlisted, 'actor' => $actor, 'id' => JsonLD::fetchElement($activity, '@id'), 'type' => $activity_type]);
1312                 }
1313
1314                 return $receivers;
1315         }
1316
1317         /**
1318          * Fetch the receiver list of a given actor
1319          *
1320          * @param string  $actor
1321          * @param array   $tags
1322          * @param array   $receivers
1323          * @param integer $target_type
1324          * @param array   $profile
1325          *
1326          * @return array with receivers (user id)
1327          * @throws \Exception
1328          */
1329         private static function getReceiverForActor(string $actor, array $tags, array $receivers, int $target_type, array $profile): array
1330         {
1331                 $basecondition = ['rel' => [Contact::SHARING, Contact::FRIEND, Contact::FOLLOWER],
1332                         'network' => Protocol::FEDERATED, 'archive' => false, 'pending' => false];
1333
1334                 if (!empty($profile['uri-id'])) {
1335                         $condition = DBA::mergeConditions($basecondition, ["`uri-id` = ? AND `uid` != ?", $profile['uri-id'], 0]);
1336                         $contacts = DBA::select('contact', ['uid', 'rel'], $condition);
1337                         while ($contact = DBA::fetch($contacts)) {
1338                                 if (empty($receivers[$contact['uid']]) && self::isValidReceiverForActor($contact, $tags)) {
1339                                         $receivers[$contact['uid']] = ['uid' => $contact['uid'], 'type' => $target_type];
1340                                 }
1341                         }
1342                         DBA::close($contacts);
1343                 } else {
1344                         // This part will only be called while post update 1426 wasn't finished
1345                         $condition = DBA::mergeConditions($basecondition, ["`nurl` = ? AND `uid` != ?", Strings::normaliseLink($actor), 0]);
1346                         $contacts = DBA::select('contact', ['uid', 'rel'], $condition);
1347                         while ($contact = DBA::fetch($contacts)) {
1348                                 if (empty($receivers[$contact['uid']]) && self::isValidReceiverForActor($contact, $tags)) {
1349                                         $receivers[$contact['uid']] = ['uid' => $contact['uid'], 'type' => $target_type];
1350                                 }
1351                         }
1352                         DBA::close($contacts);
1353
1354                         // The queries are split because of performance issues
1355                         $condition = DBA::mergeConditions($basecondition, ["`alias` IN (?, ?) AND `uid` != ?", Strings::normaliseLink($actor), $actor, 0]);
1356                         $contacts = DBA::select('contact', ['uid', 'rel'], $condition);
1357                         while ($contact = DBA::fetch($contacts)) {
1358                                 if (empty($receivers[$contact['uid']]) && self::isValidReceiverForActor($contact, $tags)) {
1359                                         $receivers[$contact['uid']] = ['uid' => $contact['uid'], 'type' => $target_type];
1360                                 }
1361                         }
1362                         DBA::close($contacts);
1363                 }
1364                 return $receivers;
1365         }
1366
1367         /**
1368          * Tests if the contact is a valid receiver for this actor
1369          *
1370          * @param array  $contact
1371          * @param array  $tags
1372          *
1373          * @return bool with receivers (user id)
1374          * @throws \Exception
1375          */
1376         private static function isValidReceiverForActor(array $contact, array $tags): bool
1377         {
1378                 // Are we following the contact? Then this is a valid receiver
1379                 if (in_array($contact['rel'], [Contact::SHARING, Contact::FRIEND])) {
1380                         return true;
1381                 }
1382
1383                 // When the possible receiver isn't a community, then it is no valid receiver
1384                 $owner = User::getOwnerDataById($contact['uid']);
1385                 if (empty($owner) || ($owner['contact-type'] != Contact::TYPE_COMMUNITY)) {
1386                         return false;
1387                 }
1388
1389                 // Is the community account tagged?
1390                 foreach ($tags as $tag) {
1391                         if ($tag['type'] != 'Mention') {
1392                                 continue;
1393                         }
1394
1395                         if (Strings::compareLink($tag['href'], $owner['url'])) {
1396                                 return true;
1397                         }
1398                 }
1399
1400                 return false;
1401         }
1402
1403         /**
1404          * Switches existing contacts to ActivityPub
1405          *
1406          * @param integer $cid Contact ID
1407          * @param integer $uid User ID
1408          * @param string  $url Profile URL
1409          * @return void
1410          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1411          * @throws \ImagickException
1412          */
1413         public static function switchContact(int $cid, int $uid, string $url)
1414         {
1415                 if (DBA::exists('contact', ['id' => $cid, 'network' => Protocol::ACTIVITYPUB])) {
1416                         Logger::info('Contact is already ActivityPub', ['id' => $cid, 'uid' => $uid, 'url' => $url]);
1417                         return;
1418                 }
1419
1420                 if (Contact::updateFromProbe($cid)) {
1421                         Logger::info('Update was successful', ['id' => $cid, 'uid' => $uid, 'url' => $url]);
1422                 }
1423
1424                 // Send a new follow request to be sure that the connection still exists
1425                 if (($uid != 0) && DBA::exists('contact', ['id' => $cid, 'rel' => [Contact::SHARING, Contact::FRIEND], 'network' => Protocol::ACTIVITYPUB])) {
1426                         Logger::info('Contact had been switched to ActivityPub. Sending a new follow request.', ['uid' => $uid, 'url' => $url]);
1427                         ActivityPub\Transmitter::sendActivity('Follow', $url, $uid);
1428                 }
1429         }
1430
1431         /**
1432          * @TODO Fix documentation and type-hints
1433          *
1434          * @param $receivers
1435          * @param $actor
1436          * @return void
1437          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1438          * @throws \ImagickException
1439          */
1440         private static function switchContacts($receivers, $actor)
1441         {
1442                 if (empty($actor)) {
1443                         return;
1444                 }
1445
1446                 foreach ($receivers as $receiver) {
1447                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver['uid'], 'network' => Protocol::OSTATUS, 'nurl' => Strings::normaliseLink($actor)]);
1448                         if (DBA::isResult($contact)) {
1449                                 self::switchContact($contact['id'], $receiver['uid'], $actor);
1450                         }
1451
1452                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver['uid'], 'network' => Protocol::OSTATUS, 'alias' => [Strings::normaliseLink($actor), $actor]]);
1453                         if (DBA::isResult($contact)) {
1454                                 self::switchContact($contact['id'], $receiver['uid'], $actor);
1455                         }
1456                 }
1457         }
1458
1459         /**
1460          * @TODO Fix documentation and type-hints
1461          *
1462          * @param       $object_data
1463          * @param array $activity
1464          *
1465          * @return mixed
1466          */
1467         private static function addActivityFields($object_data, array $activity)
1468         {
1469                 if (!empty($activity['published']) && empty($object_data['published'])) {
1470                         $object_data['published'] = JsonLD::fetchElement($activity, 'as:published', '@value');
1471                 }
1472
1473                 if (!empty($activity['diaspora:guid']) && empty($object_data['diaspora:guid'])) {
1474                         $object_data['diaspora:guid'] = JsonLD::fetchElement($activity, 'diaspora:guid', '@value');
1475                 }
1476
1477                 $object_data['service'] = JsonLD::fetchElement($activity, 'as:instrument', 'as:name', '@type', 'as:Service');
1478                 $object_data['service'] = JsonLD::fetchElement($object_data, 'service', '@value');
1479
1480                 if (!empty($object_data['object_id'])) {
1481                         // Some systems (e.g. GNU Social) don't reply to the "id" field but the "uri" field.
1482                         $objectId = Item::getURIByLink($object_data['object_id']);
1483                         if (!empty($objectId) && ($object_data['object_id'] != $objectId)) {
1484                                 Logger::notice('Fix wrong object-id', ['received' => $object_data['object_id'], 'correct' => $objectId]);
1485                                 $object_data['object_id'] = $objectId;
1486                         }
1487                 }
1488
1489                 return $object_data;
1490         }
1491
1492         /**
1493          * Fetches the object data from external resources if needed
1494          *
1495          * @param string  $object_id    Object ID of the provided object
1496          * @param array   $object       The provided object array
1497          * @param boolean $trust_source Do we trust the provided object?
1498          * @param integer $uid          User ID for the signature that we use to fetch data
1499          *
1500          * @return array|false with trusted and valid object data
1501          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1502          * @throws \ImagickException
1503          */
1504         private static function fetchObject(string $object_id, array $object = [], bool $trust_source = false, int $uid = 0)
1505         {
1506                 // By fetching the type we check if the object is complete.
1507                 $type = JsonLD::fetchElement($object, '@type');
1508
1509                 if (!$trust_source || empty($type)) {
1510                         $data = Processor::fetchCachedActivity($object_id, $uid);
1511                         if (!empty($data)) {
1512                                 $object = JsonLD::compact($data);
1513                                 Logger::info('Fetched content for ' . $object_id);
1514                         } else {
1515                                 Logger::info('Empty content for ' . $object_id . ', check if content is available locally.');
1516
1517                                 $item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['uri' => $object_id]);
1518                                 if (!DBA::isResult($item)) {
1519                                         Logger::info('Object with url ' . $object_id . ' was not found locally.');
1520                                         return false;
1521                                 }
1522                                 Logger::info('Using already stored item for url ' . $object_id);
1523                                 $data = ActivityPub\Transmitter::createNote($item);
1524                                 $object = JsonLD::compact($data);
1525                         }
1526
1527                         $id = JsonLD::fetchElement($object, '@id');
1528                         if (empty($id)) {
1529                                 Logger::info('Empty id');
1530                                 return false;
1531                         }
1532
1533                         if ($id != $object_id) {
1534                                 Logger::info('Fetched id differs from provided id', ['provided' => $object_id, 'fetched' => $id]);
1535                                 return false;
1536                         }
1537                 } else {
1538                         Logger::info('Using original object for url ' . $object_id);
1539                 }
1540
1541                 $type = JsonLD::fetchElement($object, '@type');
1542                 if (empty($type)) {
1543                         Logger::info('Empty type');
1544                         return false;
1545                 }
1546
1547                 // We currently don't handle 'pt:CacheFile', but with this step we avoid logging
1548                 if (in_array($type, self::CONTENT_TYPES) || ($type == 'pt:CacheFile')) {
1549                         $object_data = self::processObject($object, '');
1550
1551                         if (!empty($data)) {
1552                                 $object_data['raw-object'] = json_encode($data);
1553                         }
1554                         return $object_data;
1555                 }
1556
1557                 Logger::info('Unhandled object type: ' . $type);
1558                 return false;
1559         }
1560
1561         /**
1562          * Converts the language element (Used by Peertube)
1563          *
1564          * @param array $languages
1565          * @return array Languages
1566          */
1567         public static function processLanguages(array $languages): array
1568         {
1569                 if (empty($languages)) {
1570                         return [];
1571                 }
1572
1573                 $language_list = [];
1574
1575                 foreach ($languages as $language) {
1576                         if (!empty($language['_:identifier']) && !empty($language['as:name'])) {
1577                                 $language_list[$language['_:identifier']] = $language['as:name'];
1578                         }
1579                 }
1580                 return $language_list;
1581         }
1582
1583         /**
1584          * Convert tags from JSON-LD format into a simplified format
1585          *
1586          * @param array $tags Tags in JSON-LD format
1587          *
1588          * @return array with tags in a simplified format
1589          */
1590         public static function processTags(array $tags): array
1591         {
1592                 $taglist = [];
1593
1594                 foreach ($tags as $tag) {
1595                         if (empty($tag)) {
1596                                 continue;
1597                         }
1598
1599                         $element = ['type' => str_replace('as:', '', JsonLD::fetchElement($tag, '@type') ?? ''),
1600                                 'href' => JsonLD::fetchElement($tag, 'as:href', '@id'),
1601                                 'name' => JsonLD::fetchElement($tag, 'as:name', '@value')];
1602
1603                         if (empty($element['type'])) {
1604                                 continue;
1605                         }
1606
1607                         if (empty($element['href'])) {
1608                                 $element['href'] = $element['name'];
1609                         }
1610
1611                         $taglist[] = $element;
1612                 }
1613                 return $taglist;
1614         }
1615
1616         /**
1617          * Convert emojis from JSON-LD format into a simplified format
1618          *
1619          * @param array $emojis
1620          * @return array with emojis in a simplified format
1621          */
1622         private static function processEmojis(array $emojis): array
1623         {
1624                 $emojilist = [];
1625
1626                 foreach ($emojis as $emoji) {
1627                         if (empty($emoji) || (JsonLD::fetchElement($emoji, '@type') != 'toot:Emoji') || empty($emoji['as:icon'])) {
1628                                 continue;
1629                         }
1630
1631                         $url = JsonLD::fetchElement($emoji['as:icon'], 'as:url', '@id');
1632                         $element = ['name' => JsonLD::fetchElement($emoji, 'as:name', '@value'),
1633                                 'href' => $url];
1634
1635                         $emojilist[] = $element;
1636                 }
1637
1638                 return $emojilist;
1639         }
1640
1641         /**
1642          * Convert attachments from JSON-LD format into a simplified format
1643          *
1644          * @param array $attachments Attachments in JSON-LD format
1645          *
1646          * @return array Attachments in a simplified format
1647          */
1648         private static function processAttachments(array $attachments): array
1649         {
1650                 $attachlist = [];
1651
1652                 // Removes empty values
1653                 $attachments = array_filter($attachments);
1654
1655                 foreach ($attachments as $attachment) {
1656                         switch (JsonLD::fetchElement($attachment, '@type')) {
1657                                 case 'as:Page':
1658                                         $pageUrl = null;
1659                                         $pageImage = null;
1660
1661                                         $urls = JsonLD::fetchElementArray($attachment, 'as:url');
1662                                         foreach ($urls as $url) {
1663                                                 // Single scalar URL case
1664                                                 if (is_string($url)) {
1665                                                         $pageUrl = $url;
1666                                                         continue;
1667                                                 }
1668
1669                                                 $href = JsonLD::fetchElement($url, 'as:href', '@id');
1670                                                 $mediaType = JsonLD::fetchElement($url, 'as:mediaType', '@value');
1671                                                 if (Strings::startsWith($mediaType, 'image')) {
1672                                                         $pageImage = $href;
1673                                                 } else {
1674                                                         $pageUrl = $href;
1675                                                 }
1676                                         }
1677
1678                                         $attachlist[] = [
1679                                                 'type'  => 'link',
1680                                                 'title' => JsonLD::fetchElement($attachment, 'as:name', '@value'),
1681                                                 'desc'  => JsonLD::fetchElement($attachment, 'as:summary', '@value'),
1682                                                 'url'   => $pageUrl,
1683                                                 'image' => $pageImage,
1684                                         ];
1685                                         break;
1686                                 case 'as:Image':
1687                                         $mediaType = JsonLD::fetchElement($attachment, 'as:mediaType', '@value');
1688                                         $imageFullUrl = JsonLD::fetchElement($attachment, 'as:url', '@id');
1689                                         $imagePreviewUrl = null;
1690                                         // Multiple URLs?
1691                                         if (!$imageFullUrl && ($urls = JsonLD::fetchElementArray($attachment, 'as:url'))) {
1692                                                 $imageVariants = [];
1693                                                 $previewVariants = [];
1694                                                 foreach ($urls as $url) {
1695                                                         // Scalar URL, no discrimination possible
1696                                                         if (is_string($url)) {
1697                                                                 $imageFullUrl = $url;
1698                                                                 continue;
1699                                                         }
1700
1701                                                         // Not sure what to do with a different Link media type than the base Image, we skip
1702                                                         if ($mediaType != JsonLD::fetchElement($url, 'as:mediaType', '@value')) {
1703                                                                 continue;
1704                                                         }
1705
1706                                                         $href = JsonLD::fetchElement($url, 'as:href', '@id');
1707
1708                                                         // Default URL choice if no discriminating width is provided
1709                                                         $imageFullUrl = $href ?? $imageFullUrl;
1710
1711                                                         $width = intval(JsonLD::fetchElement($url, 'as:width', '@value') ?? 1);
1712
1713                                                         if ($href && $width) {
1714                                                                 $imageVariants[$width] = $href;
1715                                                                 // 632 is the ideal width for full screen frio posts, we compute the absolute distance to it
1716                                                                 $previewVariants[abs(632 - $width)] = $href;
1717                                                         }
1718                                                 }
1719
1720                                                 if ($imageVariants) {
1721                                                         // Taking the maximum size image
1722                                                         ksort($imageVariants);
1723                                                         $imageFullUrl = array_pop($imageVariants);
1724
1725                                                         // Taking the minimum number distance to the target distance
1726                                                         ksort($previewVariants);
1727                                                         $imagePreviewUrl = array_shift($previewVariants);
1728                                                 }
1729
1730                                                 unset($imageVariants);
1731                                                 unset($previewVariants);
1732                                         }
1733
1734                                         $attachlist[] = [
1735                                                 'type' => str_replace('as:', '', JsonLD::fetchElement($attachment, '@type')),
1736                                                 'mediaType' => $mediaType,
1737                                                 'name'  => JsonLD::fetchElement($attachment, 'as:name', '@value'),
1738                                                 'url'   => $imageFullUrl,
1739                                                 'image' => $imagePreviewUrl !== $imageFullUrl ? $imagePreviewUrl : null,
1740                                         ];
1741                                         break;
1742                                 default:
1743                                         $attachlist[] = [
1744                                                 'type' => str_replace('as:', '', JsonLD::fetchElement($attachment, '@type')),
1745                                                 'mediaType' => JsonLD::fetchElement($attachment, 'as:mediaType', '@value'),
1746                                                 'name' => JsonLD::fetchElement($attachment, 'as:name', '@value'),
1747                                                 'url' => JsonLD::fetchElement($attachment, 'as:url', '@id') ?? JsonLD::fetchElement($attachment, 'as:href', '@id'),
1748                                                 'height' => JsonLD::fetchElement($attachment, 'as:height', '@value'),
1749                                                 'width' => JsonLD::fetchElement($attachment, 'as:width', '@value'),
1750                                                 'image' => JsonLD::fetchElement($attachment, 'as:image', '@id')
1751                                         ];
1752                         }
1753                 }
1754
1755                 return $attachlist;
1756         }
1757
1758         /**
1759          * Convert questions from JSON-LD format into a simplified format
1760          *
1761          * @param array $object
1762          *
1763          * @return array Questions in a simplified format
1764          */
1765         private static function processQuestion(array $object): array
1766         {
1767                 $question = [];
1768
1769                 if (!empty($object['as:oneOf'])) {
1770                         $question['multiple'] = false;
1771                         $options = JsonLD::fetchElementArray($object, 'as:oneOf') ?? [];
1772                 } elseif (!empty($object['as:anyOf'])) {
1773                         $question['multiple'] = true;
1774                         $options = JsonLD::fetchElementArray($object, 'as:anyOf') ?? [];
1775                 } else {
1776                         return [];
1777                 }
1778
1779                 $closed = JsonLD::fetchElement($object, 'as:closed', '@value');
1780                 if (!empty($closed)) {
1781                         $question['end-time'] = $closed;
1782                 } else {
1783                         $question['end-time'] = JsonLD::fetchElement($object, 'as:endTime', '@value');
1784                 }
1785
1786                 $question['voters']  = (int)JsonLD::fetchElement($object, 'toot:votersCount', '@value');
1787                 $question['options'] = [];
1788
1789                 $voters = 0;
1790
1791                 foreach ($options as $option) {
1792                         if (JsonLD::fetchElement($option, '@type') != 'as:Note') {
1793                                 continue;
1794                         }
1795
1796                         $name = JsonLD::fetchElement($option, 'as:name', '@value');
1797
1798                         if (empty($option['as:replies'])) {
1799                                 continue;
1800                         }
1801
1802                         $replies = JsonLD::fetchElement($option['as:replies'], 'as:totalItems', '@value');
1803
1804                         $question['options'][] = ['name' => $name, 'replies' => $replies];
1805
1806                         $voters += (int)$replies;
1807                 }
1808
1809                 // For single choice question we can count the number of voters if not provided (like with Misskey)
1810                 if (empty($question['voters']) && !$question['multiple']) {
1811                         $question['voters'] = $voters;
1812                 }
1813
1814                 return $question;
1815         }
1816
1817         /**
1818          * Fetch the original source or content with the "language" Markdown or HTML
1819          *
1820          * @param array $object
1821          * @param array $object_data
1822          *
1823          * @return array Object data (?)
1824          * @throws \Exception
1825          */
1826         private static function getSource(array $object, array $object_data): array
1827         {
1828                 $object_data['source'] = JsonLD::fetchElement($object, 'as:source', 'as:content', 'as:mediaType', 'text/bbcode');
1829                 $object_data['source'] = JsonLD::fetchElement($object_data, 'source', '@value');
1830                 if (!empty($object_data['source'])) {
1831                         return $object_data;
1832                 }
1833
1834                 $object_data['source'] = JsonLD::fetchElement($object, 'as:source', 'as:content', 'as:mediaType', 'text/markdown');
1835                 $object_data['source'] = JsonLD::fetchElement($object_data, 'source', '@value');
1836                 if (!empty($object_data['source'])) {
1837                         $object_data['source'] = Markdown::toBBCode($object_data['source']);
1838                         return $object_data;
1839                 }
1840
1841                 $object_data['source'] = JsonLD::fetchElement($object, 'as:source', 'as:content', 'as:mediaType', 'text/html');
1842                 $object_data['source'] = JsonLD::fetchElement($object_data, 'source', '@value');
1843                 if (!empty($object_data['source'])) {
1844                         $object_data['source'] = HTML::toBBCode($object_data['source']);
1845                         return $object_data;
1846                 }
1847
1848                 return $object_data;
1849         }
1850
1851         /**
1852          * Extracts a potential alternate URL from a list of additional URL elements
1853          *
1854          * @param array $urls
1855          * @return string
1856          */
1857         private static function extractAlternateUrl(array $urls): string
1858         {
1859                 $alternateUrl = '';
1860                 foreach ($urls as $key => $url) {
1861                         // Not a list but a single URL element
1862                         if (!is_numeric($key)) {
1863                                 continue;
1864                         }
1865
1866                         if (empty($url['@type']) || ($url['@type'] != 'as:Link')) {
1867                                 continue;
1868                         }
1869
1870                         $href = JsonLD::fetchElement($url, 'as:href', '@id');
1871                         if (empty($href)) {
1872                                 continue;
1873                         }
1874
1875                         $mediatype = JsonLD::fetchElement($url, 'as:mediaType');
1876                         if (empty($mediatype)) {
1877                                 continue;
1878                         }
1879
1880                         if ($mediatype == 'text/html') {
1881                                 $alternateUrl = $href;
1882                         }
1883                 }
1884
1885                 return $alternateUrl;
1886         }
1887
1888         /**
1889          * Check if the "as:url" element is an array with multiple links
1890          * This is the case with audio and video posts.
1891          * Then the links are added as attachments
1892          *
1893          * @param array $urls The object URL list
1894          * @return array an array of attachments
1895          */
1896         private static function processAttachmentUrls(array $urls): array
1897         {
1898                 $attachments = [];
1899                 foreach ($urls as $key => $url) {
1900                         // Not a list but a single URL element
1901                         if (!is_numeric($key)) {
1902                                 continue;
1903                         }
1904
1905                         if (empty($url['@type']) || ($url['@type'] != 'as:Link')) {
1906                                 continue;
1907                         }
1908
1909                         $href = JsonLD::fetchElement($url, 'as:href', '@id');
1910                         if (empty($href)) {
1911                                 continue;
1912                         }
1913
1914                         $mediatype = JsonLD::fetchElement($url, 'as:mediaType');
1915                         if (empty($mediatype)) {
1916                                 continue;
1917                         }
1918
1919                         $filetype = strtolower(substr($mediatype, 0, strpos($mediatype, '/')));
1920
1921                         if ($filetype == 'audio') {
1922                                 $attachments[] = ['type' => $filetype, 'mediaType' => $mediatype, 'url' => $href, 'height' => null, 'size' => null, 'name' => ''];
1923                         } elseif ($filetype == 'video') {
1924                                 $height = (int)JsonLD::fetchElement($url, 'as:height', '@value');
1925                                 // PeerTube audio-only track
1926                                 if ($height === 0) {
1927                                         continue;
1928                                 }
1929
1930                                 $size = (int)JsonLD::fetchElement($url, 'pt:size', '@value');
1931                                 $attachments[] = ['type' => $filetype, 'mediaType' => $mediatype, 'url' => $href, 'height' => $height, 'size' => $size, 'name' => ''];
1932                         } elseif (in_array($mediatype, ['application/x-bittorrent', 'application/x-bittorrent;x-scheme-handler/magnet'])) {
1933                                 $height = (int)JsonLD::fetchElement($url, 'as:height', '@value');
1934
1935                                 // For Torrent links we always store the highest resolution
1936                                 if (!empty($attachments[$mediatype]['height']) && ($height < $attachments[$mediatype]['height'])) {
1937                                         continue;
1938                                 }
1939
1940                                 $attachments[$mediatype] = ['type' => $mediatype, 'mediaType' => $mediatype, 'url' => $href, 'height' => $height, 'size' => null, 'name' => ''];
1941                         } elseif ($mediatype == 'application/x-mpegURL') {
1942                                 // PeerTube exception, actual video link is in the tags of this URL element
1943                                 $attachments = array_merge($attachments, self::processAttachmentUrls($url['as:tag']));
1944                         }
1945                 }
1946
1947                 return array_values($attachments);
1948         }
1949
1950         /**
1951          * Fetches data from the object part of an activity
1952          *
1953          * @param array  $object
1954          * @param string $actor
1955          *
1956          * @return array|bool Object data or FALSE if $object does not contain @id element
1957          * @throws \Exception
1958          */
1959         private static function processObject(array $object, string $actor)
1960         {
1961                 if (!JsonLD::fetchElement($object, '@id')) {
1962                         return false;
1963                 }
1964
1965                 $object_data = self::getObjectDataFromActivity($object);
1966
1967                 $receiverdata = self::getReceivers($object, $actor ?: $object_data['actor'] ?? '', $object_data['tags'], true, false);
1968                 $receivers = $reception_types = [];
1969                 foreach ($receiverdata as $key => $data) {
1970                         $receivers[$key] = $data['uid'];
1971                         $reception_types[$data['uid']] = $data['type'] ?? 0;
1972                 }
1973
1974                 $object_data['receiver_urls']  = self::getReceiverURL($object);
1975                 $object_data['receiver']       = $receivers;
1976                 $object_data['reception_type'] = $reception_types;
1977
1978                 $object_data['unlisted'] = in_array(-1, $object_data['receiver']);
1979                 unset($object_data['receiver'][-1]);
1980                 unset($object_data['reception_type'][-1]);
1981
1982                 return $object_data;
1983         }
1984
1985         /**
1986          * Create an object data array from a given activity
1987          *
1988          * @param array $object
1989          *
1990          * @return array Object data
1991          */
1992         public static function getObjectDataFromActivity(array $object): array
1993         {
1994                 $object_data = [];
1995                 $object_data['object_type'] = JsonLD::fetchElement($object, '@type');
1996                 $object_data['id'] = JsonLD::fetchElement($object, '@id');
1997                 $object_data['reply-to-id'] = JsonLD::fetchElement($object, 'as:inReplyTo', '@id');
1998
1999                 // An empty "id" field is translated to "./" by the compactor, so we have to check for this content
2000                 if (empty($object_data['reply-to-id']) || ($object_data['reply-to-id'] == './')) {
2001                         $object_data['reply-to-id'] = $object_data['id'];
2002
2003                         // On activities the "reply to" is the id of the object it refers to
2004                         if (in_array($object_data['object_type'], array_merge(self::ACTIVITY_TYPES, ['as:Announce']))) {
2005                                 $object_id = JsonLD::fetchElement($object, 'as:object', '@id');
2006                                 if (!empty($object_id)) {
2007                                         $object_data['reply-to-id'] = $object_id;
2008                                 }
2009                         }
2010                 } else {
2011                         // Some systems (e.g. GNU Social) don't reply to the "id" field but the "uri" field.
2012                         $replyToId = Item::getURIByLink($object_data['reply-to-id']);
2013                         if (!empty($replyToId) && ($object_data['reply-to-id'] != $replyToId)) {
2014                                 Logger::notice('Fix wrong reply-to', ['received' => $object_data['reply-to-id'], 'correct' => $replyToId]);
2015                                 $object_data['reply-to-id'] = $replyToId;
2016                         }
2017                 }
2018
2019                 $object_data['published'] = JsonLD::fetchElement($object, 'as:published', '@value');
2020                 $object_data['updated'] = JsonLD::fetchElement($object, 'as:updated', '@value');
2021
2022                 if (empty($object_data['updated'])) {
2023                         $object_data['updated'] = $object_data['published'];
2024                 }
2025
2026                 if (empty($object_data['published']) && !empty($object_data['updated'])) {
2027                         $object_data['published'] = $object_data['updated'];
2028                 }
2029
2030                 $actor = JsonLD::fetchElement($object, 'as:attributedTo', '@id');
2031                 if (empty($actor)) {
2032                         $actor = JsonLD::fetchElement($object, 'as:actor', '@id');
2033                 }
2034
2035                 $location = JsonLD::fetchElement($object, 'as:location', 'as:name', '@type', 'as:Place');
2036                 $location = JsonLD::fetchElement($location, 'location', '@value');
2037                 if ($location) {
2038                         // Some AP software allow formatted text in post location, so we run all the text converters we have to boil
2039                         // down to HTML and then finally format to plaintext.
2040                         $location = Markdown::convert($location);
2041                         $location = BBCode::toPlaintext($location);
2042                 }
2043
2044                 $object_data['sc:identifier'] = JsonLD::fetchElement($object, 'sc:identifier', '@value');
2045                 $object_data['diaspora:guid'] = JsonLD::fetchElement($object, 'diaspora:guid', '@value');
2046                 $object_data['diaspora:comment'] = JsonLD::fetchElement($object, 'diaspora:comment', '@value');
2047                 $object_data['diaspora:like'] = JsonLD::fetchElement($object, 'diaspora:like', '@value');
2048                 $object_data['actor'] = $object_data['author'] = $actor;
2049                 $element = JsonLD::fetchElement($object, 'as:context', '@id');
2050                 $object_data['context'] = $element != './' ? $element : null;
2051                 $element = JsonLD::fetchElement($object, 'ostatus:conversation', '@id');
2052                 $object_data['conversation'] = $element != './' ? $element : null;
2053                 $object_data['sensitive'] = JsonLD::fetchElement($object, 'as:sensitive');
2054                 $object_data['name'] = JsonLD::fetchElement($object, 'as:name', '@value');
2055                 $object_data['summary'] = JsonLD::fetchElement($object, 'as:summary', '@value');
2056                 $object_data['content'] = JsonLD::fetchElement($object, 'as:content', '@value');
2057                 $object_data['mediatype'] = JsonLD::fetchElement($object, 'as:mediaType', '@value');
2058                 $object_data = self::getSource($object, $object_data);
2059                 $object_data['start-time'] = JsonLD::fetchElement($object, 'as:startTime', '@value');
2060                 $object_data['end-time'] = JsonLD::fetchElement($object, 'as:endTime', '@value');
2061                 $object_data['location'] = $location;
2062                 $object_data['latitude'] = JsonLD::fetchElement($object, 'as:location', 'as:latitude', '@type', 'as:Place');
2063                 $object_data['latitude'] = JsonLD::fetchElement($object_data, 'latitude', '@value');
2064                 $object_data['longitude'] = JsonLD::fetchElement($object, 'as:location', 'as:longitude', '@type', 'as:Place');
2065                 $object_data['longitude'] = JsonLD::fetchElement($object_data, 'longitude', '@value');
2066                 $object_data['attachments'] = self::processAttachments(JsonLD::fetchElementArray($object, 'as:attachment') ?? []);
2067                 $object_data['tags'] = self::processTags(JsonLD::fetchElementArray($object, 'as:tag') ?? []);
2068                 $object_data['emojis'] = self::processEmojis(JsonLD::fetchElementArray($object, 'as:tag', null, '@type', 'toot:Emoji') ?? []);
2069                 $object_data['languages'] = self::processLanguages(JsonLD::fetchElementArray($object, 'sc:inLanguage') ?? []);
2070                 $object_data['transmitted-languages'] = Processor::getPostLanguages($object);
2071                 $object_data['generator'] = JsonLD::fetchElement($object, 'as:generator', 'as:name', '@type', 'as:Application');
2072                 $object_data['generator'] = JsonLD::fetchElement($object_data, 'generator', '@value');
2073                 $object_data['alternate-url'] = JsonLD::fetchElement($object, 'as:url', '@id');
2074
2075                 // Special treatment for Hubzilla links
2076                 if (is_array($object_data['alternate-url'])) {
2077                         $object_data['alternate-url'] = JsonLD::fetchElement($object_data['alternate-url'], 'as:href', '@id');
2078
2079                         if (!is_string($object_data['alternate-url'])) {
2080                                 $object_data['alternate-url'] = JsonLD::fetchElement($object['as:url'], 'as:href', '@id');
2081                         }
2082                 }
2083
2084                 if (!empty($object_data['alternate-url']) && !Network::isValidHttpUrl($object_data['alternate-url'])) {
2085                         $object_data['alternate-url'] = null;
2086                 }
2087
2088                 if (in_array($object_data['object_type'], ['as:Audio', 'as:Video'])) {
2089                         $object_data['alternate-url'] = self::extractAlternateUrl($object['as:url'] ?? []) ?: $object_data['alternate-url'];
2090                         $object_data['attachments'] = array_merge($object_data['attachments'], self::processAttachmentUrls($object['as:url'] ?? []));
2091                 }
2092
2093                 // Support for quoted posts (Pleroma, Fedibird and Misskey)
2094                 $object_data['quote-url'] = JsonLD::fetchElement($object, 'as:quoteUrl', '@value');
2095                 if (empty($object_data['quote-url'])) {
2096                         $object_data['quote-url'] = JsonLD::fetchElement($object, 'fedibird:quoteUri', '@value');
2097                 }
2098                 if (empty($object_data['quote-url'])) {
2099                         $object_data['quote-url'] = JsonLD::fetchElement($object, 'misskey:_misskey_quote', '@value');
2100                 }
2101
2102                 // Misskey adds some data to the standard "content" value for quoted posts for backwards compatibility.
2103                 // Their own "_misskey_content" value does then contain the content without this extra data.
2104                 if (!empty($object_data['quote-url'])) {
2105                         $misskey_content = JsonLD::fetchElement($object, 'misskey:_misskey_content', '@value');
2106                         if (!empty($misskey_content)) {
2107                                 $object_data['content'] = $misskey_content;
2108                         }
2109                 }
2110
2111                 // For page types we expect that the alternate url posts to some page.
2112                 // So we add this to the attachments if it differs from the id.
2113                 // Currently only Lemmy is using the page type.
2114                 if (($object_data['object_type'] == 'as:Page') && !empty($object_data['alternate-url']) && !Strings::compareLink($object_data['alternate-url'], $object_data['id'])) {
2115                         $object_data['attachments'][] = ['url' => $object_data['alternate-url']];
2116                         $object_data['alternate-url'] = null;
2117                 }
2118
2119                 if ($object_data['object_type'] == 'as:Question') {
2120                         $object_data['question'] = self::processQuestion($object);
2121                 }
2122
2123                 return $object_data;
2124         }
2125
2126         /**
2127          * Add an object id to the list of arrived activities
2128          *
2129          * @param string $id
2130          *
2131          * @return void
2132          */
2133         private static function addArrivedId(string $id)
2134         {
2135                 DBA::delete('arrived-activity', ["`received` < ?", DateTimeFormat::utc('now - 5 minutes')]);
2136                 DBA::insert('arrived-activity', ['object-id' => $id, 'received' => DateTimeFormat::utcNow()], Database::INSERT_IGNORE);
2137         }
2138
2139         /**
2140          * Checks if the given object already arrived before
2141          *
2142          * @param string $id
2143          *
2144          * @return boolean
2145          */
2146         private static function hasArrived(string $id): bool
2147         {
2148                 return DBA::exists('arrived-activity', ['object-id' => $id]);
2149         }
2150 }