src/Protocol/ActivityPub/Receiver.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   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\Model\Contact;
  31 use Friendica\Model\APContact;
  32 use Friendica\Model\Item;
  33 use Friendica\Model\User;
  34 use Friendica\Protocol\Activity;
  35 use Friendica\Protocol\ActivityPub;
  36 use Friendica\Util\DateTimeFormat;
  37 use Friendica\Util\HTTPSignature;
  38 use Friendica\Util\JsonLD;
  39 use Friendica\Util\LDSignature;
  40 use Friendica\Util\Strings;
  41
  42 /**
  43  * ActivityPub Receiver Protocol class
  44  *
  45  * To-Do:
  46  * @todo Undo Announce
  47  *
  48  * Check what this is meant to do:
  49  * - Add
  50  * - Block
  51  * - Flag
  52  * - Remove
  53  * - Undo Block
  54  */
  55 class Receiver
  56 {
  57         const PUBLIC_COLLECTION = 'as:Public';
  58         const ACCOUNT_TYPES = ['as:Person', 'as:Organization', 'as:Service', 'as:Group', 'as:Application'];
  59         const CONTENT_TYPES = ['as:Note', 'as:Article', 'as:Video', 'as:Image', 'as:Event', 'as:Audio'];
  60         const ACTIVITY_TYPES = ['as:Like', 'as:Dislike', 'as:Accept', 'as:Reject', 'as:TentativeAccept'];
  61
  62         /**
  63          * Checks if the web request is done for the AP protocol
  64          *
  65          * @return bool is it AP?
  66          */
  67         public static function isRequest()
  68         {
  69                 return stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/activity+json') ||
  70                         stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/ld+json');
  71         }
  72
  73         /**
  74          * Checks incoming message from the inbox
  75          *
  76          * @param         $body
  77          * @param         $header
  78          * @param integer $uid User ID
  79          * @throws \Exception
  80          */
  81         public static function processInbox($body, $header, $uid)
  82         {
  83                 $http_signer = HTTPSignature::getSigner($body, $header);
  84                 if (empty($http_signer)) {
  85                         Logger::warning('Invalid HTTP signature, message will be discarded.');
  86                         return;
  87                 } else {
  88                         Logger::info('Valid HTTP signature', ['signer' => $http_signer]);
  89                 }
  90
  91                 $activity = json_decode($body, true);
  92
  93                 if (empty($activity)) {
  94                         Logger::warning('Invalid body.');
  95                         return;
  96                 }
  97
  98                 $ldactivity = JsonLD::compact($activity);
  99
 100                 $actor = JsonLD::fetchElement($ldactivity, 'as:actor', '@id');
 101
 102                 Logger::info('Message for user ' . $uid . ' is from actor ' . $actor);
 103
 104                 if (LDSignature::isSigned($activity)) {
 105                         $ld_signer = LDSignature::getSigner($activity);
 106                         if (empty($ld_signer)) {
 107                                 Logger::log('Invalid JSON-LD signature from ' . $actor, Logger::DEBUG);
 108                         }
 109                         if (!empty($ld_signer && ($actor == $http_signer))) {
 110                                 Logger::log('The HTTP and the JSON-LD signature belong to ' . $ld_signer, Logger::DEBUG);
 111                                 $trust_source = true;
 112                         } elseif (!empty($ld_signer)) {
 113                                 Logger::log('JSON-LD signature is signed by ' . $ld_signer, Logger::DEBUG);
 114                                 $trust_source = true;
 115                         } elseif ($actor == $http_signer) {
 116                                 Logger::log('Bad JSON-LD signature, but HTTP signer fits the actor.', Logger::DEBUG);
 117                                 $trust_source = true;
 118                         } else {
 119                                 Logger::log('Invalid JSON-LD signature and the HTTP signer is different.', Logger::DEBUG);
 120                                 $trust_source = false;
 121                         }
 122                 } elseif ($actor == $http_signer) {
 123                         Logger::log('Trusting post without JSON-LD signature, The actor fits the HTTP signer.', Logger::DEBUG);
 124                         $trust_source = true;
 125                 } else {
 126                         Logger::log('No JSON-LD signature, different actor.', Logger::DEBUG);
 127                         $trust_source = false;
 128                 }
 129
 130                 self::processActivity($ldactivity, $body, $uid, $trust_source, true);
 131         }
 132
 133         /**
 134          * Fetches the object type for a given object id
 135          *
 136          * @param array   $activity
 137          * @param string  $object_id Object ID of the the provided object
 138          * @param integer $uid       User ID
 139          *
 140          * @return string with object type
 141          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 142          * @throws \ImagickException
 143          */
 144         private static function fetchObjectType($activity, $object_id, $uid = 0)
 145         {
 146                 if (!empty($activity['as:object'])) {
 147                         $object_type = JsonLD::fetchElement($activity['as:object'], '@type');
 148                         if (!empty($object_type)) {
 149                                 return $object_type;
 150                         }
 151                 }
 152
 153                 if (Item::exists(['uri' => $object_id, 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT]])) {
 154                         // We just assume "note" since it doesn't make a difference for the further processing
 155                         return 'as:Note';
 156                 }
 157
 158                 $profile = APContact::getByURL($object_id);
 159                 if (!empty($profile['type'])) {
 160                         return 'as:' . $profile['type'];
 161                 }
 162
 163                 $data = ActivityPub::fetchContent($object_id, $uid);
 164                 if (!empty($data)) {
 165                         $object = JsonLD::compact($data);
 166                         $type = JsonLD::fetchElement($object, '@type');
 167                         if (!empty($type)) {
 168                                 return $type;
 169                         }
 170                 }
 171
 172                 return null;
 173         }
 174
 175         /**
 176          * Prepare the object array
 177          *
 178          * @param array   $activity     Array with activity data
 179          * @param integer $uid          User ID
 180          * @param boolean $push         Message had been pushed to our system
 181          * @param boolean $trust_source Do we trust the source?
 182          *
 183          * @return array with object data
 184          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 185          * @throws \ImagickException
 186          */
 187         public static function prepareObjectData($activity, $uid, $push, &$trust_source)
 188         {
 189                 $actor = JsonLD::fetchElement($activity, 'as:actor', '@id');
 190                 if (empty($actor)) {
 191                         Logger::log('Empty actor', Logger::DEBUG);
 192                         return [];
 193                 }
 194
 195                 $type = JsonLD::fetchElement($activity, '@type');
 196
 197                 // Fetch all receivers from to, cc, bto and bcc
 198                 $receivers = self::getReceivers($activity, $actor);
 199
 200                 // When it is a delivery to a personal inbox we add that user to the receivers
 201                 if (!empty($uid)) {
 202                         $additional = ['uid:' . $uid => $uid];
 203                         $receivers = array_merge($receivers, $additional);
 204                 } else {
 205                         // We possibly need some user to fetch private content,
 206                         // so we fetch the first out ot the list.
 207                         $uid = self::getFirstUserFromReceivers($receivers);
 208                 }
 209
 210                 $object_id = JsonLD::fetchElement($activity, 'as:object', '@id');
 211                 if (empty($object_id)) {
 212                         Logger::log('No object found', Logger::DEBUG);
 213                         return [];
 214                 }
 215
 216                 if (!is_string($object_id)) {
 217                         Logger::info('Invalid object id', ['object' => $object_id]);
 218                         return [];
 219                 }
 220
 221                 $object_type = self::fetchObjectType($activity, $object_id, $uid);
 222
 223                 // Fetch the content only on activities where this matters
 224                 if (in_array($type, ['as:Create', 'as:Update', 'as:Announce'])) {
 225                         if ($type == 'as:Announce') {
 226                                 $trust_source = false;
 227                         }
 228
 229                         $object_data = self::fetchObject($object_id, $activity['as:object'], $trust_source, $uid);
 230                         if (empty($object_data)) {
 231                                 Logger::log("Object data couldn't be processed", Logger::DEBUG);
 232                                 return [];
 233                         }
 234
 235                         $object_data['object_id'] = $object_id;
 236
 237                         if ($type == 'as:Announce') {
 238                                 $object_data['push'] = false;
 239                         } else {
 240                                 $object_data['push'] = $push;
 241                         }
 242
 243                         // Test if it is an answer to a mail
 244                         if (DBA::exists('mail', ['uri' => $object_data['reply-to-id']])) {
 245                                 $object_data['directmessage'] = true;
 246                         } else {
 247                                 $object_data['directmessage'] = JsonLD::fetchElement($activity, 'litepub:directMessage');
 248                         }
 249
 250                         // We had been able to retrieve the object data - so we can trust the source
 251                         $trust_source = true;
 252                 } elseif (in_array($type, array_merge(self::ACTIVITY_TYPES, ['as:Follow'])) && in_array($object_type, self::CONTENT_TYPES)) {
 253                         // Create a mostly empty array out of the activity data (instead of the object).
 254                         // This way we later don't have to check for the existence of ech individual array element.
 255                         $object_data = self::processObject($activity);
 256                         $object_data['name'] = $type;
 257                         $object_data['author'] = JsonLD::fetchElement($activity, 'as:actor', '@id');
 258                         $object_data['object_id'] = $object_id;
 259                         $object_data['object_type'] = ''; // Since we don't fetch the object, we don't know the type
 260                 } elseif (in_array($type, ['as:Add'])) {
 261                         $object_data = [];
 262                         $object_data['id'] = JsonLD::fetchElement($activity, '@id');
 263                         $object_data['target_id'] = JsonLD::fetchElement($activity, 'as:target', '@id');
 264                         $object_data['object_id'] = JsonLD::fetchElement($activity, 'as:object', '@id');
 265                         $object_data['object_type'] = JsonLD::fetchElement($activity['as:object'], '@type');
 266                         $object_data['object_content'] = JsonLD::fetchElement($activity['as:object'], 'as:content', '@type');
 267                 } else {
 268                         $object_data = [];
 269                         $object_data['id'] = JsonLD::fetchElement($activity, '@id');
 270                         $object_data['object_id'] = JsonLD::fetchElement($activity, 'as:object', '@id');
 271                         $object_data['object_actor'] = JsonLD::fetchElement($activity['as:object'], 'as:actor', '@id');
 272                         $object_data['object_object'] = JsonLD::fetchElement($activity['as:object'], 'as:object');
 273                         $object_data['object_type'] = JsonLD::fetchElement($activity['as:object'], '@type');
 274
 275                         // An Undo is done on the object of an object, so we need that type as well
 276                         if (($type == 'as:Undo') && !empty($object_data['object_object'])) {
 277                                 $object_data['object_object_type'] = self::fetchObjectType([], $object_data['object_object'], $uid);
 278                         }
 279                 }
 280
 281                 $object_data = self::addActivityFields($object_data, $activity);
 282
 283                 if (empty($object_data['object_type'])) {
 284                         $object_data['object_type'] = $object_type;
 285                 }
 286
 287                 $object_data['type'] = $type;
 288                 $object_data['actor'] = $actor;
 289                 $object_data['item_receiver'] = $receivers;
 290                 $object_data['receiver'] = array_merge($object_data['receiver'] ?? [], $receivers);
 291
 292                 Logger::log('Processing ' . $object_data['type'] . ' ' . $object_data['object_type'] . ' ' . $object_data['id'], Logger::DEBUG);
 293
 294                 return $object_data;
 295         }
 296
 297         /**
 298          * Fetches the first user id from the receiver array
 299          *
 300          * @param array $receivers Array with receivers
 301          * @return integer user id;
 302          */
 303         public static function getFirstUserFromReceivers($receivers)
 304         {
 305                 foreach ($receivers as $receiver) {
 306                         if (!empty($receiver)) {
 307                                 return $receiver;
 308                         }
 309                 }
 310                 return 0;
 311         }
 312
 313         /**
 314          * Processes the activity object
 315          *
 316          * @param array   $activity     Array with activity data
 317          * @param string  $body
 318          * @param integer $uid          User ID
 319          * @param boolean $trust_source Do we trust the source?
 320          * @param boolean $push         Message had been pushed to our system
 321          * @throws \Exception
 322          */
 323         public static function processActivity($activity, $body = '', $uid = null, $trust_source = false, $push = false)
 324         {
 325                 $type = JsonLD::fetchElement($activity, '@type');
 326                 if (!$type) {
 327                         Logger::log('Empty type', Logger::DEBUG);
 328                         return;
 329                 }
 330
 331                 if (!JsonLD::fetchElement($activity, 'as:object', '@id')) {
 332                         Logger::log('Empty object', Logger::DEBUG);
 333                         return;
 334                 }
 335
 336                 if (!JsonLD::fetchElement($activity, 'as:actor', '@id')) {
 337                         Logger::log('Empty actor', Logger::DEBUG);
 338                         return;
 339                 }
 340
 341                 // Don't trust the source if "actor" differs from "attributedTo". The content could be forged.
 342                 if ($trust_source && ($type == 'as:Create') && is_array($activity['as:object'])) {
 343                         $actor = JsonLD::fetchElement($activity, 'as:actor', '@id');
 344                         $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
 345                         $trust_source = ($actor == $attributed_to);
 346                         if (!$trust_source) {
 347                                 Logger::log('Not trusting actor: ' . $actor . '. It differs from attributedTo: ' . $attributed_to, Logger::DEBUG);
 348                         }
 349                 }
 350
 351                 // $trust_source is called by reference and is set to true if the content was retrieved successfully
 352                 $object_data = self::prepareObjectData($activity, $uid, $push, $trust_source);
 353                 if (empty($object_data)) {
 354                         Logger::log('No object data found', Logger::DEBUG);
 355                         return;
 356                 }
 357
 358                 if (!$trust_source) {
 359                         Logger::log('No trust for activity type "' . $type . '", so we quit now.', Logger::DEBUG);
 360                         return;
 361                 }
 362
 363                 if (!empty($body) && empty($object_data['raw'])) {
 364                         $object_data['raw'] = $body;
 365                 }
 366
 367                 // Internal flag for thread completion. See Processor.php
 368                 if (!empty($activity['thread-completion'])) {
 369                         $object_data['thread-completion'] = $activity['thread-completion'];
 370                 }
 371
 372                 switch ($type) {
 373                         case 'as:Create':
 374                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 375                                         $item = ActivityPub\Processor::createItem($object_data);
 376                                         ActivityPub\Processor::postItem($object_data, $item);
 377                                 }
 378                                 break;
 379
 380                         case 'as:Add':
 381                                 if ($object_data['object_type'] == 'as:tag') {
 382                                         ActivityPub\Processor::addTag($object_data);
 383                                 }
 384                                 break;
 385
 386                         case 'as:Announce':
 387                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 388                                         $object_data['thread-completion'] = true;
 389
 390                                         $item = ActivityPub\Processor::createItem($object_data);
 391                                         ActivityPub\Processor::postItem($object_data, $item);
 392
 393                                         $announce_object_data = self::processObject($activity);
 394                                         $announce_object_data['name'] = $type;
 395                                         $announce_object_data['author'] = JsonLD::fetchElement($activity, 'as:actor', '@id');
 396                                         $announce_object_data['object_id'] = $object_data['object_id'];
 397                                         $announce_object_data['object_type'] = $object_data['object_type'];
 398                                         $announce_object_data['push'] = $push;
 399
 400                                         if (!empty($body)) {
 401                                                 $announce_object_data['raw'] = $body;
 402                                         }
 403
 404                                         ActivityPub\Processor::createActivity($announce_object_data, Activity::ANNOUNCE);
 405                                 }
 406                                 break;
 407
 408                         case 'as:Like':
 409                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 410                                         ActivityPub\Processor::createActivity($object_data, Activity::LIKE);
 411                                 }
 412                                 break;
 413
 414                         case 'as:Dislike':
 415                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 416                                         ActivityPub\Processor::createActivity($object_data, Activity::DISLIKE);
 417                                 }
 418                                 break;
 419
 420                         case 'as:TentativeAccept':
 421                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 422                                         ActivityPub\Processor::createActivity($object_data, Activity::ATTENDMAYBE);
 423                                 }
 424                                 break;
 425
 426                         case 'as:Update':
 427                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 428                                         ActivityPub\Processor::updateItem($object_data);
 429                                 } elseif (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 430                                         ActivityPub\Processor::updatePerson($object_data);
 431                                 }
 432                                 break;
 433
 434                         case 'as:Delete':
 435                                 if ($object_data['object_type'] == 'as:Tombstone') {
 436                                         ActivityPub\Processor::deleteItem($object_data);
 437                                 } elseif (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 438                                         ActivityPub\Processor::deletePerson($object_data);
 439                                 }
 440                                 break;
 441
 442                         case 'as:Follow':
 443                                 if (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 444                                         ActivityPub\Processor::followUser($object_data);
 445                                 } elseif (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 446                                         $object_data['reply-to-id'] = $object_data['object_id'];
 447                                         ActivityPub\Processor::createActivity($object_data, Activity::FOLLOW);
 448                                 }
 449                                 break;
 450
 451                         case 'as:Accept':
 452                                 if ($object_data['object_type'] == 'as:Follow') {
 453                                         ActivityPub\Processor::acceptFollowUser($object_data);
 454                                 } elseif (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 455                                         ActivityPub\Processor::createActivity($object_data, Activity::ATTEND);
 456                                 }
 457                                 break;
 458
 459                         case 'as:Reject':
 460                                 if ($object_data['object_type'] == 'as:Follow') {
 461                                         ActivityPub\Processor::rejectFollowUser($object_data);
 462                                 } elseif (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 463                                         ActivityPub\Processor::createActivity($object_data, Activity::ATTENDNO);
 464                                 }
 465                                 break;
 466
 467                         case 'as:Undo':
 468                                 if (($object_data['object_type'] == 'as:Follow') &&
 469                                         in_array($object_data['object_object_type'], self::ACCOUNT_TYPES)) {
 470                                         ActivityPub\Processor::undoFollowUser($object_data);
 471                                 } elseif (($object_data['object_type'] == 'as:Accept') &&
 472                                         in_array($object_data['object_object_type'], self::ACCOUNT_TYPES)) {
 473                                         ActivityPub\Processor::rejectFollowUser($object_data);
 474                                 } elseif (in_array($object_data['object_type'], self::ACTIVITY_TYPES) &&
 475                                         in_array($object_data['object_object_type'], self::CONTENT_TYPES)) {
 476                                         ActivityPub\Processor::undoActivity($object_data);
 477                                 }
 478                                 break;
 479
 480                         default:
 481                                 Logger::log('Unknown activity: ' . $type . ' ' . $object_data['object_type'], Logger::DEBUG);
 482                                 break;
 483                 }
 484         }
 485
 486         /**
 487          * Fetch the receiver list from an activity array
 488          *
 489          * @param array   $activity
 490          * @param string  $actor
 491          * @param array   $tags
 492          * @param boolean $fetch_unlisted
 493          *
 494          * @return array with receivers (user id)
 495          * @throws \Exception
 496          */
 497         private static function getReceivers($activity, $actor, $tags = [], $fetch_unlisted = false)
 498         {
 499                 $receivers = [];
 500
 501                 // When it is an answer, we inherite the receivers from the parent
 502                 $replyto = JsonLD::fetchElement($activity, 'as:inReplyTo', '@id');
 503                 if (!empty($replyto)) {
 504                         // Fix possibly wrong item URI (could be an answer to a plink uri)
 505                         $fixedReplyTo = Item::getURIByLink($replyto);
 506                         $replyto = $fixedReplyTo ?: $replyto;
 507
 508                         $parents = Item::select(['uid'], ['uri' => $replyto]);
 509                         while ($parent = Item::fetch($parents)) {
 510                                 $receivers['uid:' . $parent['uid']] = $parent['uid'];
 511                         }
 512                 }
 513
 514                 if (!empty($actor)) {
 515                         $profile = APContact::getByURL($actor);
 516                         $followers = $profile['followers'] ?? '';
 517
 518                         Logger::log('Actor: ' . $actor . ' - Followers: ' . $followers, Logger::DEBUG);
 519                 } else {
 520                         Logger::log('Empty actor', Logger::DEBUG);
 521                         $followers = '';
 522                 }
 523
 524                 foreach (['as:to', 'as:cc', 'as:bto', 'as:bcc'] as $element) {
 525                         $receiver_list = JsonLD::fetchElementArray($activity, $element, '@id');
 526                         if (empty($receiver_list)) {
 527                                 continue;
 528                         }
 529
 530                         foreach ($receiver_list as $receiver) {
 531                                 if ($receiver == self::PUBLIC_COLLECTION) {
 532                                         $receivers['uid:0'] = 0;
 533                                 }
 534
 535                                 // Add receiver "-1" for unlisted posts
 536                                 if ($fetch_unlisted && ($receiver == self::PUBLIC_COLLECTION) && ($element == 'as:cc')) {
 537                                         $receivers['uid:-1'] = -1;
 538                                 }
 539
 540                                 // Fetch the receivers for the public and the followers collection
 541                                 if (in_array($receiver, [$followers, self::PUBLIC_COLLECTION]) && !empty($actor)) {
 542                                         $receivers = array_merge($receivers, self::getReceiverForActor($actor, $tags));
 543                                         continue;
 544                                 }
 545
 546                                 // Fetching all directly addressed receivers
 547                                 $condition = ['self' => true, 'nurl' => Strings::normaliseLink($receiver)];
 548                                 $contact = DBA::selectFirst('contact', ['uid', 'contact-type'], $condition);
 549                                 if (!DBA::isResult($contact)) {
 550                                         continue;
 551                                 }
 552
 553                                 // Check if the potential receiver is following the actor
 554                                 // Exception: The receiver is targetted via "to" or this is a comment
 555                                 if ((($element != 'as:to') && empty($replyto)) || ($contact['contact-type'] == Contact::TYPE_COMMUNITY)) {
 556                                         $networks = Protocol::FEDERATED;
 557                                         $condition = ['nurl' => Strings::normaliseLink($actor), 'rel' => [Contact::SHARING, Contact::FRIEND],
 558                                                 'network' => $networks, 'archive' => false, 'pending' => false, 'uid' => $contact['uid']];
 559
 560                                         // Forum posts are only accepted from forum contacts
 561                                         if ($contact['contact-type'] == Contact::TYPE_COMMUNITY) {
 562                                                 $condition['rel'] = [Contact::SHARING, Contact::FRIEND, Contact::FOLLOWER];
 563                                         }
 564
 565                                         if (!DBA::exists('contact', $condition)) {
 566                                                 continue;
 567                                         }
 568                                 }
 569
 570                                 $receivers['uid:' . $contact['uid']] = $contact['uid'];
 571                         }
 572                 }
 573
 574                 self::switchContacts($receivers, $actor);
 575
 576                 return $receivers;
 577         }
 578
 579         /**
 580          * Fetch the receiver list of a given actor
 581          *
 582          * @param string $actor
 583          * @param array  $tags
 584          *
 585          * @return array with receivers (user id)
 586          * @throws \Exception
 587          */
 588         private static function getReceiverForActor($actor, $tags)
 589         {
 590                 $receivers = [];
 591                 $basecondition = ['rel' => [Contact::SHARING, Contact::FRIEND, Contact::FOLLOWER],
 592                         'network' => Protocol::FEDERATED, 'archive' => false, 'pending' => false];
 593
 594                 $condition = DBA::mergeConditions($basecondition, ['nurl' => Strings::normaliseLink($actor)]);
 595                 $contacts = DBA::select('contact', ['uid', 'rel'], $condition);
 596                 while ($contact = DBA::fetch($contacts)) {
 597                         if (self::isValidReceiverForActor($contact, $actor, $tags)) {
 598                                 $receivers['uid:' . $contact['uid']] = $contact['uid'];
 599                         }
 600                 }
 601                 DBA::close($contacts);
 602
 603                 // The queries are split because of performance issues
 604                 $condition = DBA::mergeConditions($basecondition, ["`alias` IN (?, ?)", Strings::normaliseLink($actor), $actor]);
 605                 $contacts = DBA::select('contact', ['uid', 'rel'], $condition);
 606                 while ($contact = DBA::fetch($contacts)) {
 607                         if (self::isValidReceiverForActor($contact, $actor, $tags)) {
 608                                 $receivers['uid:' . $contact['uid']] = $contact['uid'];
 609                         }
 610                 }
 611                 DBA::close($contacts);
 612                 return $receivers;
 613         }
 614
 615         /**
 616          * Tests if the contact is a valid receiver for this actor
 617          *
 618          * @param array  $contact
 619          * @param string $actor
 620          * @param array  $tags
 621          *
 622          * @return bool with receivers (user id)
 623          * @throws \Exception
 624          */
 625         private static function isValidReceiverForActor($contact, $actor, $tags)
 626         {
 627                 // Public contacts are no valid receiver
 628                 if ($contact['uid'] == 0) {
 629                         return false;
 630                 }
 631
 632                 // Are we following the contact? Then this is a valid receiver
 633                 if (in_array($contact['rel'], [Contact::SHARING, Contact::FRIEND])) {
 634                         return true;
 635                 }
 636
 637                 // When the possible receiver isn't a community, then it is no valid receiver
 638                 $owner = User::getOwnerDataById($contact['uid']);
 639                 if (empty($owner) || ($owner['contact-type'] != Contact::TYPE_COMMUNITY)) {
 640                         return false;
 641                 }
 642
 643                 // Is the community account tagged?
 644                 foreach ($tags as $tag) {
 645                         if ($tag['type'] != 'Mention') {
 646                                 continue;
 647                         }
 648
 649                         if ($tag['href'] == $owner['url']) {
 650                                 return true;
 651                         }
 652                 }
 653
 654                 return false;
 655         }
 656
 657         /**
 658          * Switches existing contacts to ActivityPub
 659          *
 660          * @param integer $cid Contact ID
 661          * @param integer $uid User ID
 662          * @param string  $url Profile URL
 663          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 664          * @throws \ImagickException
 665          */
 666         public static function switchContact($cid, $uid, $url)
 667         {
 668                 if (DBA::exists('contact', ['id' => $cid, 'network' => Protocol::ACTIVITYPUB])) {
 669                         Logger::info('Contact is already ActivityPub', ['id' => $cid, 'uid' => $uid, 'url' => $url]);
 670                         return;
 671                 }
 672
 673                 if (Contact::updateFromProbe($cid)) {
 674                         Logger::info('Update was successful', ['id' => $cid, 'uid' => $uid, 'url' => $url]);
 675                 }
 676
 677                 // Send a new follow request to be sure that the connection still exists
 678                 if (($uid != 0) && DBA::exists('contact', ['id' => $cid, 'rel' => [Contact::SHARING, Contact::FRIEND], 'network' => Protocol::ACTIVITYPUB])) {
 679                         Logger::info('Contact had been switched to ActivityPub. Sending a new follow request.', ['uid' => $uid, 'url' => $url]);
 680                         ActivityPub\Transmitter::sendActivity('Follow', $url, $uid);
 681                 }
 682         }
 683
 684         /**
 685          *
 686          *
 687          * @param $receivers
 688          * @param $actor
 689          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 690          * @throws \ImagickException
 691          */
 692         private static function switchContacts($receivers, $actor)
 693         {
 694                 if (empty($actor)) {
 695                         return;
 696                 }
 697
 698                 foreach ($receivers as $receiver) {
 699                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver, 'network' => Protocol::OSTATUS, 'nurl' => Strings::normaliseLink($actor)]);
 700                         if (DBA::isResult($contact)) {
 701                                 self::switchContact($contact['id'], $receiver, $actor);
 702                         }
 703
 704                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver, 'network' => Protocol::OSTATUS, 'alias' => [Strings::normaliseLink($actor), $actor]]);
 705                         if (DBA::isResult($contact)) {
 706                                 self::switchContact($contact['id'], $receiver, $actor);
 707                         }
 708                 }
 709         }
 710
 711         /**
 712          *
 713          *
 714          * @param       $object_data
 715          * @param array $activity
 716          *
 717          * @return mixed
 718          */
 719         private static function addActivityFields($object_data, $activity)
 720         {
 721                 if (!empty($activity['published']) && empty($object_data['published'])) {
 722                         $object_data['published'] = JsonLD::fetchElement($activity, 'as:published', '@value');
 723                 }
 724
 725                 if (!empty($activity['diaspora:guid']) && empty($object_data['diaspora:guid'])) {
 726                         $object_data['diaspora:guid'] = JsonLD::fetchElement($activity, 'diaspora:guid', '@value');
 727                 }
 728
 729                 $object_data['service'] = JsonLD::fetchElement($activity, 'as:instrument', 'as:name', '@type', 'as:Service');
 730                 $object_data['service'] = JsonLD::fetchElement($object_data, 'service', '@value');
 731
 732                 if (!empty($object_data['object_id'])) {
 733                         // Some systems (e.g. GNU Social) don't reply to the "id" field but the "uri" field.
 734                         $objectId = Item::getURIByLink($object_data['object_id']);
 735                         if (!empty($objectId) && ($object_data['object_id'] != $objectId)) {
 736                                 Logger::notice('Fix wrong object-id', ['received' => $object_data['object_id'], 'correct' => $objectId]);
 737                                 $object_data['object_id'] = $objectId;
 738                         }
 739                 }
 740
 741                 return $object_data;
 742         }
 743
 744         /**
 745          * Fetches the object data from external ressources if needed
 746          *
 747          * @param string  $object_id    Object ID of the the provided object
 748          * @param array   $object       The provided object array
 749          * @param boolean $trust_source Do we trust the provided object?
 750          * @param integer $uid          User ID for the signature that we use to fetch data
 751          *
 752          * @return array|false with trusted and valid object data
 753          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 754          * @throws \ImagickException
 755          */
 756         private static function fetchObject(string $object_id, array $object = [], bool $trust_source = false, int $uid = 0)
 757         {
 758                 // By fetching the type we check if the object is complete.
 759                 $type = JsonLD::fetchElement($object, '@type');
 760
 761                 if (!$trust_source || empty($type)) {
 762                         $data = ActivityPub::fetchContent($object_id, $uid);
 763                         if (!empty($data)) {
 764                                 $object = JsonLD::compact($data);
 765                                 Logger::log('Fetched content for ' . $object_id, Logger::DEBUG);
 766                         } else {
 767                                 Logger::log('Empty content for ' . $object_id . ', check if content is available locally.', Logger::DEBUG);
 768
 769                                 $item = Item::selectFirst([], ['uri' => $object_id]);
 770                                 if (!DBA::isResult($item)) {
 771                                         Logger::log('Object with url ' . $object_id . ' was not found locally.', Logger::DEBUG);
 772                                         return false;
 773                                 }
 774                                 Logger::log('Using already stored item for url ' . $object_id, Logger::DEBUG);
 775                                 $data = ActivityPub\Transmitter::createNote($item);
 776                                 $object = JsonLD::compact($data);
 777                         }
 778                 } else {
 779                         Logger::log('Using original object for url ' . $object_id, Logger::DEBUG);
 780                 }
 781
 782                 $type = JsonLD::fetchElement($object, '@type');
 783
 784                 if (empty($type)) {
 785                         Logger::log('Empty type', Logger::DEBUG);
 786                         return false;
 787                 }
 788
 789                 if (in_array($type, self::CONTENT_TYPES)) {
 790                         $object_data = self::processObject($object);
 791
 792                         if (!empty($data)) {
 793                                 $object_data['raw'] = json_encode($data);
 794                         }
 795                         return $object_data;
 796                 }
 797
 798                 if ($type == 'as:Announce') {
 799                         $object_id = JsonLD::fetchElement($object, 'object', '@id');
 800                         if (empty($object_id) || !is_string($object_id)) {
 801                                 return false;
 802                         }
 803                         return self::fetchObject($object_id, [], false, $uid);
 804                 }
 805
 806                 Logger::log('Unhandled object type: ' . $type, Logger::DEBUG);
 807                 return false;
 808         }
 809
 810         /**
 811          * Convert tags from JSON-LD format into a simplified format
 812          *
 813          * @param array $tags Tags in JSON-LD format
 814          *
 815          * @return array with tags in a simplified format
 816          */
 817         private static function processTags(array $tags)
 818         {
 819                 $taglist = [];
 820
 821                 foreach ($tags as $tag) {
 822                         if (empty($tag)) {
 823                                 continue;
 824                         }
 825
 826                         $element = ['type' => str_replace('as:', '', JsonLD::fetchElement($tag, '@type')),
 827                                 'href' => JsonLD::fetchElement($tag, 'as:href', '@id'),
 828                                 'name' => JsonLD::fetchElement($tag, 'as:name', '@value')];
 829
 830                         if (empty($element['type'])) {
 831                                 continue;
 832                         }
 833
 834                         if (empty($element['href'])) {
 835                                 $element['href'] = $element['name'];
 836                         }
 837
 838                         $taglist[] = $element;
 839                 }
 840                 return $taglist;
 841         }
 842
 843         /**
 844          * Convert emojis from JSON-LD format into a simplified format
 845          *
 846          * @param array $emojis
 847          * @return array with emojis in a simplified format
 848          */
 849         private static function processEmojis(array $emojis)
 850         {
 851                 $emojilist = [];
 852
 853                 foreach ($emojis as $emoji) {
 854                         if (empty($emoji) || (JsonLD::fetchElement($emoji, '@type') != 'toot:Emoji') || empty($emoji['as:icon'])) {
 855                                 continue;
 856                         }
 857
 858                         $url = JsonLD::fetchElement($emoji['as:icon'], 'as:url', '@id');
 859                         $element = ['name' => JsonLD::fetchElement($emoji, 'as:name', '@value'),
 860                                 'href' => $url];
 861
 862                         $emojilist[] = $element;
 863                 }
 864
 865                 return $emojilist;
 866         }
 867
 868         /**
 869          * Convert attachments from JSON-LD format into a simplified format
 870          *
 871          * @param array $attachments Attachments in JSON-LD format
 872          *
 873          * @return array Attachments in a simplified format
 874          */
 875         private static function processAttachments(array $attachments)
 876         {
 877                 $attachlist = [];
 878
 879                 // Removes empty values
 880                 $attachments = array_filter($attachments);
 881
 882                 foreach ($attachments as $attachment) {
 883                         switch (JsonLD::fetchElement($attachment, '@type')) {
 884                                 case 'as:Page':
 885                                         $pageUrl = null;
 886                                         $pageImage = null;
 887
 888                                         $urls = JsonLD::fetchElementArray($attachment, 'as:url');
 889                                         foreach ($urls as $url) {
 890                                                 // Single scalar URL case
 891                                                 if (is_string($url)) {
 892                                                         $pageUrl = $url;
 893                                                         continue;
 894                                                 }
 895
 896                                                 $href = JsonLD::fetchElement($url, 'as:href', '@id');
 897                                                 $mediaType = JsonLD::fetchElement($url, 'as:mediaType', '@value');
 898                                                 if (Strings::startsWith($mediaType, 'image')) {
 899                                                         $pageImage = $href;
 900                                                 } else {
 901                                                         $pageUrl = $href;
 902                                                 }
 903                                         }
 904
 905                                         $attachlist[] = [
 906                                                 'type'  => 'link',
 907                                                 'title' => JsonLD::fetchElement($attachment, 'as:name', '@value'),
 908                                                 'desc'  => JsonLD::fetchElement($attachment, 'as:summary', '@value'),
 909                                                 'url'   => $pageUrl,
 910                                                 'image' => $pageImage,
 911                                         ];
 912                                         break;
 913                                 case 'as:Link':
 914                                         $attachlist[] = [
 915                                                 'type' => str_replace('as:', '', JsonLD::fetchElement($attachment, '@type')),
 916                                                 'mediaType' => JsonLD::fetchElement($attachment, 'as:mediaType', '@value'),
 917                                                 'name' => JsonLD::fetchElement($attachment, 'as:name', '@value'),
 918                                                 'url' => JsonLD::fetchElement($attachment, 'as:href', '@id')
 919                                         ];
 920                                         break;
 921                                 case 'as:Image':
 922                                         $mediaType = JsonLD::fetchElement($attachment, 'as:mediaType', '@value');
 923                                         $imageFullUrl = JsonLD::fetchElement($attachment, 'as:url', '@id');
 924                                         $imagePreviewUrl = null;
 925                                         // Multiple URLs?
 926                                         if (!$imageFullUrl && ($urls = JsonLD::fetchElementArray($attachment, 'as:url'))) {
 927                                                 $imageVariants = [];
 928                                                 $previewVariants = [];
 929                                                 foreach ($urls as $url) {
 930                                                         // Scalar URL, no discrimination possible
 931                                                         if (is_string($url)) {
 932                                                                 $imageFullUrl = $url;
 933                                                                 continue;
 934                                                         }
 935
 936                                                         // Not sure what to do with a different Link media type than the base Image, we skip
 937                                                         if ($mediaType != JsonLD::fetchElement($url, 'as:mediaType', '@value')) {
 938                                                                 continue;
 939                                                         }
 940
 941                                                         $href = JsonLD::fetchElement($url, 'as:href', '@id');
 942
 943                                                         // Default URL choice if no discriminating width is provided
 944                                                         $imageFullUrl = $href ?? $imageFullUrl;
 945
 946                                                         $width = intval(JsonLD::fetchElement($url, 'as:width', '@value') ?? 1);
 947
 948                                                         if ($href && $width) {
 949                                                                 $imageVariants[$width] = $href;
 950                                                                 // 632 is the ideal width for full screen frio posts, we compute the absolute distance to it
 951                                                                 $previewVariants[abs(632 - $width)] = $href;
 952                                                         }
 953                                                 }
 954
 955                                                 if ($imageVariants) {
 956                                                         // Taking the maximum size image
 957                                                         ksort($imageVariants);
 958                                                         $imageFullUrl = array_pop($imageVariants);
 959
 960                                                         // Taking the minimum number distance to the target distance
 961                                                         ksort($previewVariants);
 962                                                         $imagePreviewUrl = array_shift($previewVariants);
 963                                                 }
 964
 965                                                 unset($imageVariants);
 966                                                 unset($previewVariants);
 967                                         }
 968
 969                                         $attachlist[] = [
 970                                                 'type' => str_replace('as:', '', JsonLD::fetchElement($attachment, '@type')),
 971                                                 'mediaType' => $mediaType,
 972                                                 'name'  => JsonLD::fetchElement($attachment, 'as:name', '@value'),
 973                                                 'url'   => $imageFullUrl,
 974                                                 'image' => $imagePreviewUrl !== $imageFullUrl ? $imagePreviewUrl : null,
 975                                         ];
 976                                         break;
 977                                 default:
 978                                         $attachlist[] = [
 979                                                 'type' => str_replace('as:', '', JsonLD::fetchElement($attachment, '@type')),
 980                                                 'mediaType' => JsonLD::fetchElement($attachment, 'as:mediaType', '@value'),
 981                                                 'name' => JsonLD::fetchElement($attachment, 'as:name', '@value'),
 982                                                 'url' => JsonLD::fetchElement($attachment, 'as:url', '@id')
 983                                         ];
 984                         }
 985                 }
 986
 987                 return $attachlist;
 988         }
 989
 990         /**
 991          * Fetch the original source or content with the "language" Markdown or HTML
 992          *
 993          * @param array $object
 994          * @param array $object_data
 995          *
 996          * @return array
 997          * @throws \Exception
 998          */
 999         private static function getSource($object, $object_data)
1000         {
1001                 $object_data['source'] = JsonLD::fetchElement($object, 'as:source', 'as:content', 'as:mediaType', 'text/bbcode');
1002                 $object_data['source'] = JsonLD::fetchElement($object_data, 'source', '@value');
1003                 if (!empty($object_data['source'])) {
1004                         return $object_data;
1005                 }
1006
1007                 $object_data['source'] = JsonLD::fetchElement($object, 'as:source', 'as:content', 'as:mediaType', 'text/markdown');
1008                 $object_data['source'] = JsonLD::fetchElement($object_data, 'source', '@value');
1009                 if (!empty($object_data['source'])) {
1010                         $object_data['source'] = Markdown::toBBCode($object_data['source']);
1011                         return $object_data;
1012                 }
1013
1014                 $object_data['source'] = JsonLD::fetchElement($object, 'as:source', 'as:content', 'as:mediaType', 'text/html');
1015                 $object_data['source'] = JsonLD::fetchElement($object_data, 'source', '@value');
1016                 if (!empty($object_data['source'])) {
1017                         $object_data['source'] = HTML::toBBCode($object_data['source']);
1018                         return $object_data;
1019                 }
1020
1021                 return $object_data;
1022         }
1023
1024         /**
1025          * Check if the "as:url" element is an array with multiple links
1026          * This is the case with audio and video posts.
1027          * Then the links are added as attachments
1028          *
1029          * @param array $object      The raw object
1030          * @param array $object_data The parsed object data for later processing
1031          * @return array the object data
1032          */
1033         private static function processAttachmentUrls(array $object, array $object_data) {
1034                 // Check if this is some url with multiple links
1035                 if (empty($object['as:url'])) {
1036                         return $object_data;
1037                 }
1038
1039                 $urls = $object['as:url'];
1040                 $keys = array_keys($urls);
1041                 if (!is_numeric(array_pop($keys))) {
1042                         return $object_data;
1043                 }
1044
1045                 $attachments = [];
1046
1047                 foreach ($urls as $url) {
1048                         if (empty($url['@type']) || ($url['@type'] != 'as:Link')) {
1049                                 continue;
1050                         }
1051
1052                         $href = JsonLD::fetchElement($url, 'as:href', '@id');
1053                         if (empty($href)) {
1054                                 continue;
1055                         }
1056
1057                         $mediatype = JsonLD::fetchElement($url, 'as:mediaType');
1058                         if (empty($mediatype)) {
1059                                 continue;
1060                         }
1061
1062                         if ($mediatype == 'text/html') {
1063                                 $object_data['alternate-url'] = $href;
1064                         }
1065
1066                         $filetype = strtolower(substr($mediatype, 0, strpos($mediatype, '/')));
1067
1068                         if ($filetype == 'audio') {
1069                                 $attachments[$filetype] = ['type' => $mediatype, 'url' => $href];
1070                         } elseif ($filetype == 'video') {
1071                                 $height = (int)JsonLD::fetchElement($url, 'as:height', '@value');
1072
1073                                 // We save bandwidth by using a moderate height
1074                                 // Peertube normally uses these heights: 240, 360, 480, 720, 1080
1075                                 if (!empty($attachments[$filetype]['height']) &&
1076                                         (($height > 480) || $height < $attachments[$filetype]['height'])) {
1077                                         continue;
1078                                 }
1079
1080                                 $attachments[$filetype] = ['type' => $mediatype, 'url' => $href, 'height' => $height];
1081                         }
1082                 }
1083
1084                 foreach ($attachments as $type => $attachment) {
1085                         $object_data['attachments'][] = ['type' => $type,
1086                                 'mediaType' => $attachment['type'],
1087                                 'name' => '',
1088                                 'url' => $attachment['url']];
1089                 }
1090                 return $object_data;
1091         }
1092
1093         /**
1094          * Fetches data from the object part of an activity
1095          *
1096          * @param array $object
1097          *
1098          * @return array
1099          * @throws \Exception
1100          */
1101         private static function processObject($object)
1102         {
1103                 if (!JsonLD::fetchElement($object, '@id')) {
1104                         return false;
1105                 }
1106
1107                 $object_data = [];
1108                 $object_data['object_type'] = JsonLD::fetchElement($object, '@type');
1109                 $object_data['id'] = JsonLD::fetchElement($object, '@id');
1110                 $object_data['reply-to-id'] = JsonLD::fetchElement($object, 'as:inReplyTo', '@id');
1111
1112                 // An empty "id" field is translated to "./" by the compactor, so we have to check for this content
1113                 if (empty($object_data['reply-to-id']) || ($object_data['reply-to-id'] == './')) {
1114                         $object_data['reply-to-id'] = $object_data['id'];
1115                 } else {
1116                         // Some systems (e.g. GNU Social) don't reply to the "id" field but the "uri" field.
1117                         $replyToId = Item::getURIByLink($object_data['reply-to-id']);
1118                         if (!empty($replyToId) && ($object_data['reply-to-id'] != $replyToId)) {
1119                                 Logger::notice('Fix wrong reply-to', ['received' => $object_data['reply-to-id'], 'correct' => $replyToId]);
1120                                 $object_data['reply-to-id'] = $replyToId;
1121                         }
1122                 }
1123
1124                 $object_data['published'] = JsonLD::fetchElement($object, 'as:published', '@value');
1125                 $object_data['updated'] = JsonLD::fetchElement($object, 'as:updated', '@value');
1126
1127                 if (empty($object_data['updated'])) {
1128                         $object_data['updated'] = $object_data['published'];
1129                 }
1130
1131                 if (empty($object_data['published']) && !empty($object_data['updated'])) {
1132                         $object_data['published'] = $object_data['updated'];
1133                 }
1134
1135                 $actor = JsonLD::fetchElement($object, 'as:attributedTo', '@id');
1136                 if (empty($actor)) {
1137                         $actor = JsonLD::fetchElement($object, 'as:actor', '@id');
1138                 }
1139
1140                 $location = JsonLD::fetchElement($object, 'as:location', 'as:name', '@type', 'as:Place');
1141                 $location = JsonLD::fetchElement($location, 'location', '@value');
1142                 if ($location) {
1143                         // Some AP software allow formatted text in post location, so we run all the text converters we have to boil
1144                         // down to HTML and then finally format to plaintext.
1145                         $location = Markdown::convert($location);
1146                         $location = BBCode::convert($location);
1147                         $location = HTML::toPlaintext($location);
1148                 }
1149
1150                 $object_data['sc:identifier'] = JsonLD::fetchElement($object, 'sc:identifier', '@value');
1151                 $object_data['diaspora:guid'] = JsonLD::fetchElement($object, 'diaspora:guid', '@value');
1152                 $object_data['diaspora:comment'] = JsonLD::fetchElement($object, 'diaspora:comment', '@value');
1153                 $object_data['diaspora:like'] = JsonLD::fetchElement($object, 'diaspora:like', '@value');
1154                 $object_data['actor'] = $object_data['author'] = $actor;
1155                 $object_data['context'] = JsonLD::fetchElement($object, 'as:context', '@id');
1156                 $object_data['conversation'] = JsonLD::fetchElement($object, 'ostatus:conversation', '@id');
1157                 $object_data['sensitive'] = JsonLD::fetchElement($object, 'as:sensitive');
1158                 $object_data['name'] = JsonLD::fetchElement($object, 'as:name', '@value');
1159                 $object_data['summary'] = JsonLD::fetchElement($object, 'as:summary', '@value');
1160                 $object_data['content'] = JsonLD::fetchElement($object, 'as:content', '@value');
1161                 $object_data = self::getSource($object, $object_data);
1162                 $object_data['start-time'] = JsonLD::fetchElement($object, 'as:startTime', '@value');
1163                 $object_data['end-time'] = JsonLD::fetchElement($object, 'as:endTime', '@value');
1164                 $object_data['location'] = $location;
1165                 $object_data['latitude'] = JsonLD::fetchElement($object, 'as:location', 'as:latitude', '@type', 'as:Place');
1166                 $object_data['latitude'] = JsonLD::fetchElement($object_data, 'latitude', '@value');
1167                 $object_data['longitude'] = JsonLD::fetchElement($object, 'as:location', 'as:longitude', '@type', 'as:Place');
1168                 $object_data['longitude'] = JsonLD::fetchElement($object_data, 'longitude', '@value');
1169                 $object_data['attachments'] = self::processAttachments(JsonLD::fetchElementArray($object, 'as:attachment') ?? []);
1170                 $object_data['tags'] = self::processTags(JsonLD::fetchElementArray($object, 'as:tag') ?? []);
1171                 $object_data['emojis'] = self::processEmojis(JsonLD::fetchElementArray($object, 'as:tag', 'toot:Emoji') ?? []);
1172                 $object_data['generator'] = JsonLD::fetchElement($object, 'as:generator', 'as:name', '@type', 'as:Application');
1173                 $object_data['generator'] = JsonLD::fetchElement($object_data, 'generator', '@value');
1174                 $object_data['alternate-url'] = JsonLD::fetchElement($object, 'as:url', '@id');
1175
1176                 // Special treatment for Hubzilla links
1177                 if (is_array($object_data['alternate-url'])) {
1178                         $object_data['alternate-url'] = JsonLD::fetchElement($object_data['alternate-url'], 'as:href', '@id');
1179
1180                         if (!is_string($object_data['alternate-url'])) {
1181                                 $object_data['alternate-url'] = JsonLD::fetchElement($object['as:url'], 'as:href', '@id');
1182                         }
1183                 }
1184
1185                 if (in_array($object_data['object_type'], ['as:Audio', 'as:Video'])) {
1186                         $object_data = self::processAttachmentUrls($object, $object_data);
1187                 }
1188
1189                 $object_data['receiver'] = self::getReceivers($object, $object_data['actor'], $object_data['tags'], true);
1190                 $object_data['unlisted'] = in_array(-1, $object_data['receiver']);
1191                 unset($object_data['receiver']['uid:-1']);
1192
1193                 // Common object data:
1194
1195                 // Unhandled
1196                 // @context, type, actor, signature, mediaType, duration, replies, icon
1197
1198                 // Also missing: (Defined in the standard, but currently unused)
1199                 // audience, preview, endTime, startTime, image
1200
1201                 // Data in Notes:
1202
1203                 // Unhandled
1204                 // contentMap, announcement_count, announcements, context_id, likes, like_count
1205                 // inReplyToStatusId, shares, quoteUrl, statusnetConversationId
1206
1207                 // Data in video:
1208
1209                 // To-Do?
1210                 // category, licence, language, commentsEnabled
1211
1212                 // Unhandled
1213                 // views, waitTranscoding, state, support, subtitleLanguage
1214                 // likes, dislikes, shares, comments
1215
1216                 return $object_data;
1217         }
1218 }