src/Protocol/ActivityPub/Receiver.php

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