src/Protocol/ActivityPub/Receiver.php

   1 <?php
   2 /**
   3  * @file src/Protocol/ActivityPub/Receiver.php
   4  */
   5 namespace Friendica\Protocol\ActivityPub;
   6
   7 use Friendica\Database\DBA;
   8 use Friendica\Util\HTTPSignature;
   9 use Friendica\Core\Protocol;
  10 use Friendica\Model\Contact;
  11 use Friendica\Model\APContact;
  12 use Friendica\Model\Item;
  13 use Friendica\Model\User;
  14 use Friendica\Util\JsonLD;
  15 use Friendica\Util\LDSignature;
  16 use Friendica\Protocol\ActivityPub;
  17 use Friendica\Model\Conversation;
  18 use Friendica\Util\DateTimeFormat;
  19
  20 /**
  21  * @brief ActivityPub Receiver Protocol class
  22  *
  23  * To-Do:
  24  * - Update (Image, Video, Article, Note)
  25  * - Undo Announce
  26  * - Accept Event
  27  * - Reject Event
  28  * - TentativeAccept Even
  29  * - Undo Accept Event
  30  * - Undo Reject Event
  31  * - Undo TentativeAccept Event
  32  *
  33  * Check what this is meant to do:
  34  * - Add
  35  * - Block
  36  * - Flag
  37  * - Remove
  38  * - Undo Block
  39  * - Undo Accept Person
  40  */
  41 class Receiver
  42 {
  43         const PUBLIC_COLLECTION = 'as:Public';
  44         const ACCOUNT_TYPES = ['as:Person', 'as:Organization', 'as:Service', 'as:Group', 'as:Application'];
  45         const CONTENT_TYPES = ['as:Note', 'as:Article', 'as:Video', 'as:Image', 'as:Event'];
  46         const ACTIVITY_TYPES = ['as:Like', 'as:Dislike', 'as:Accept', 'as:Reject', 'as:TentativeAccept'];
  47
  48         /**
  49          * Checks if the web request is done for the AP protocol
  50          *
  51          * @return is it AP?
  52          */
  53         public static function isRequest()
  54         {
  55                 return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
  56                         stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
  57         }
  58
  59         /**
  60          * Checks incoming message from the inbox
  61          *
  62          * @param $body
  63          * @param $header
  64          * @param integer $uid User ID
  65          */
  66         public static function processInbox($body, $header, $uid)
  67         {
  68                 $http_signer = HTTPSignature::getSigner($body, $header);
  69                 if (empty($http_signer)) {
  70                         logger('Invalid HTTP signature, message will be discarded.', LOGGER_DEBUG);
  71                         return;
  72                 } else {
  73                         logger('HTTP signature is signed by ' . $http_signer, LOGGER_DEBUG);
  74                 }
  75
  76                 $activity = json_decode($body, true);
  77
  78                 if (empty($activity)) {
  79                         logger('Invalid body.', LOGGER_DEBUG);
  80                         return;
  81                 }
  82
  83                 $ldactivity = JsonLD::compact($activity);
  84
  85                 $actor = JsonLD::fetchElement($ldactivity, 'as:actor');
  86
  87                 logger('Message for user ' . $uid . ' is from actor ' . $actor, LOGGER_DEBUG);
  88
  89                 if (LDSignature::isSigned($activity)) {
  90                         $ld_signer = LDSignature::getSigner($activity);
  91                         if (empty($ld_signer)) {
  92                                 logger('Invalid JSON-LD signature from ' . $actor, LOGGER_DEBUG);
  93                         }
  94                         if (!empty($ld_signer && ($actor == $http_signer))) {
  95                                 logger('The HTTP and the JSON-LD signature belong to ' . $ld_signer, LOGGER_DEBUG);
  96                                 $trust_source = true;
  97                         } elseif (!empty($ld_signer)) {
  98                                 logger('JSON-LD signature is signed by ' . $ld_signer, LOGGER_DEBUG);
  99                                 $trust_source = true;
 100                         } elseif ($actor == $http_signer) {
 101                                 logger('Bad JSON-LD signature, but HTTP signer fits the actor.', LOGGER_DEBUG);
 102                                 $trust_source = true;
 103                         } else {
 104                                 logger('Invalid JSON-LD signature and the HTTP signer is different.', LOGGER_DEBUG);
 105                                 $trust_source = false;
 106                         }
 107                 } elseif ($actor == $http_signer) {
 108                         logger('Trusting post without JSON-LD signature, The actor fits the HTTP signer.', LOGGER_DEBUG);
 109                         $trust_source = true;
 110                 } else {
 111                         logger('No JSON-LD signature, different actor.', LOGGER_DEBUG);
 112                         $trust_source = false;
 113                 }
 114
 115                 self::processActivity($ldactivity, $body, $uid, $trust_source);
 116         }
 117
 118         /**
 119          * Fetches the object type for a given object id
 120          *
 121          * @param array  $activity
 122          * @param string $object_id Object ID of the the provided object
 123          *
 124          * @return string with object type
 125          */
 126         private static function fetchObjectType($activity, $object_id)
 127         {
 128
 129                 $object_type = JsonLD::fetchElement($activity['as:object'], '@type');
 130                 if (!empty($object_type)) {
 131                         return $object_type;
 132                 }
 133
 134                 if (Item::exists(['uri' => $object_id, 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT]])) {
 135                         // We just assume "note" since it doesn't make a difference for the further processing
 136                         return 'as:Note';
 137                 }
 138
 139                 $profile = APContact::getByURL($object_id);
 140                 if (!empty($profile['type'])) {
 141                         return 'as:' . $profile['type'];
 142                 }
 143
 144                 $data = ActivityPub::fetchContent($object_id);
 145                 if (!empty($data)) {
 146                         $object = JsonLD::compact($data);
 147                         $type = JsonLD::fetchElement($object, '@type');
 148                         if (!empty($type)) {
 149                                 return $type;
 150                         }
 151                 }
 152
 153                 return null;
 154         }
 155
 156         /**
 157          * Prepare the object array
 158          *
 159          * @param array $activity
 160          * @param integer $uid User ID
 161          * @param $trust_source
 162          *
 163          * @return array with object data
 164          */
 165         private static function prepareObjectData($activity, $uid, &$trust_source)
 166         {
 167                 $actor = JsonLD::fetchElement($activity, 'as:actor');
 168                 if (empty($actor)) {
 169                         logger('Empty actor', LOGGER_DEBUG);
 170                         return [];
 171                 }
 172
 173                 $type = JsonLD::fetchElement($activity, '@type');
 174
 175                 // Fetch all receivers from to, cc, bto and bcc
 176                 $receivers = self::getReceivers($activity, $actor);
 177
 178                 // When it is a delivery to a personal inbox we add that user to the receivers
 179                 if (!empty($uid)) {
 180                         $owner = User::getOwnerDataById($uid);
 181                         $additional = ['uid:' . $uid => $uid];
 182                         $receivers = array_merge($receivers, $additional);
 183                 }
 184
 185                 logger('Receivers: ' . json_encode($receivers), LOGGER_DEBUG);
 186
 187                 $object_id = JsonLD::fetchElement($activity, 'as:object');
 188                 if (empty($object_id)) {
 189                         logger('No object found', LOGGER_DEBUG);
 190                         return [];
 191                 }
 192
 193                 $object_type = self::fetchObjectType($activity, $object_id);
 194
 195                 // Fetch the content only on activities where this matters
 196                 if (in_array($type, ['as:Create', 'as:Announce'])) {
 197                         if ($type == 'as:Announce') {
 198                                 $trust_source = false;
 199                         }
 200                         $object_data = self::fetchObject($object_id, $activity['as:object'], $trust_source);
 201                         if (empty($object_data)) {
 202                                 logger("Object data couldn't be processed", LOGGER_DEBUG);
 203                                 return [];
 204                         }
 205                         // We had been able to retrieve the object data - so we can trust the source
 206                         $trust_source = true;
 207                 } elseif (in_array($type, ['as:Like', 'as:Dislike'])) {
 208                         // Create a mostly empty array out of the activity data (instead of the object).
 209                         // This way we later don't have to check for the existence of ech individual array element.
 210                         $object_data = self::processObject($activity);
 211                         $object_data['name'] = $type;
 212                         $object_data['author'] = JsonLD::fetchElement($activity, 'as:actor');
 213                         $object_data['object_id'] = $object_id;
 214                         $object_data['object_type'] = ''; // Since we don't fetch the object, we don't know the type
 215                 } else {
 216                         $object_data = [];
 217                         $object_data['id'] = JsonLD::fetchElement($activity, '@id');
 218                         $object_data['object_id'] = JsonLD::fetchElement($activity, 'as:object');
 219                         $object_data['object_actor'] = JsonLD::fetchElement($activity['as:object'], 'as:actor');
 220                         $object_data['object_object'] = JsonLD::fetchElement($activity['as:object'], 'as:object');
 221                         $object_data['object_type'] = JsonLD::fetchElement($activity['as:object'], '@type');
 222                 }
 223
 224                 $object_data = self::addActivityFields($object_data, $activity);
 225
 226                 if (empty($object_data['object_type'])) {
 227                         $object_data['object_type'] = $object_type;
 228                 }
 229
 230                 $object_data['type'] = $type;
 231                 $object_data['actor'] = $actor;
 232                 $object_data['receiver'] = array_merge(defaults($object_data, 'receiver', []), $receivers);
 233
 234                 logger('Processing ' . $object_data['type'] . ' ' . $object_data['object_type'] . ' ' . $object_data['id'], LOGGER_DEBUG);
 235
 236                 return $object_data;
 237         }
 238
 239         /**
 240          * Store the unprocessed data into the conversation table
 241          * This has to be done outside the regular function,
 242          * since we store everything - not only item posts.
 243          *
 244          * @param array  $activity Array with activity data
 245          * @param string $body     The raw message
 246          */
 247         private static function storeConversation($activity, $body)
 248         {
 249                 if (empty($body) || empty($activity['id'])) {
 250                         return;
 251                 }
 252
 253                 $conversation = [
 254                         'protocol' => Conversation::PARCEL_ACTIVITYPUB,
 255                         'item-uri' => $activity['id'],
 256                         'reply-to-uri' => defaults($activity, 'reply-to-id', ''),
 257                         'conversation-href' => defaults($activity, 'context', ''),
 258                         'conversation-uri' => defaults($activity, 'conversation', ''),
 259                         'source' => $body,
 260                         'received' => DateTimeFormat::utcNow()];
 261
 262                 DBA::insert('conversation', $conversation, true);
 263         }
 264
 265         /**
 266          * Processes the activity object
 267          *
 268          * @param array   $activity     Array with activity data
 269          * @param string  $body
 270          * @param integer $uid          User ID
 271          * @param boolean $trust_source Do we trust the source?
 272          */
 273         public static function processActivity($activity, $body = '', $uid = null, $trust_source = false)
 274         {
 275                 $type = JsonLD::fetchElement($activity, '@type');
 276                 if (!$type) {
 277                         logger('Empty type', LOGGER_DEBUG);
 278                         return;
 279                 }
 280
 281                 if (!JsonLD::fetchElement($activity, 'as:object')) {
 282                         logger('Empty object', LOGGER_DEBUG);
 283                         return;
 284                 }
 285
 286                 if (!JsonLD::fetchElement($activity, 'as:actor')) {
 287                         logger('Empty actor', LOGGER_DEBUG);
 288                         return;
 289
 290                 }
 291
 292                 // $trust_source is called by reference and is set to true if the content was retrieved successfully
 293                 $object_data = self::prepareObjectData($activity, $uid, $trust_source);
 294                 if (empty($object_data)) {
 295                         logger('No object data found', LOGGER_DEBUG);
 296                         return;
 297                 }
 298
 299                 if (!$trust_source) {
 300                         logger('No trust for activity type "' . $type . '", so we quit now.', LOGGER_DEBUG);
 301                         return;
 302                 }
 303
 304                 self::storeConversation($object_data, $body);
 305
 306                 // Internal flag for thread completion. See Processor.php
 307                 if (!empty($activity['thread-completion'])) {
 308                         $object_data['thread-completion'] = $activity['thread-completion'];
 309                 }
 310
 311                 switch ($type) {
 312                         case 'as:Create':
 313                         case 'as:Announce':
 314                                 ActivityPub\Processor::createItem($object_data);
 315                                 break;
 316
 317                         case 'as:Like':
 318                                 ActivityPub\Processor::likeItem($object_data);
 319                                 break;
 320
 321                         case 'as:Dislike':
 322                                 ActivityPub\Processor::dislikeItem($object_data);
 323                                 break;
 324
 325                         case 'as:Update':
 326                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 327                                         /// @todo
 328                                 } elseif (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 329                                         ActivityPub\Processor::updatePerson($object_data, $body);
 330                                 }
 331                                 break;
 332
 333                         case 'as:Delete':
 334                                 if ($object_data['object_type'] == 'as:Tombstone') {
 335                                         ActivityPub\Processor::deleteItem($object_data, $body);
 336                                 } elseif (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 337                                         ActivityPub\Processor::deletePerson($object_data, $body);
 338                                 }
 339                                 break;
 340
 341                         case 'as:Follow':
 342                                 ActivityPub\Processor::followUser($object_data);
 343                                 break;
 344
 345                         case 'as:Accept':
 346                                 if ($object_data['object_type'] == 'as:Follow') {
 347                                         ActivityPub\Processor::acceptFollowUser($object_data);
 348                                 }
 349                                 break;
 350
 351                         case 'as:Reject':
 352                                 if ($object_data['object_type'] == 'as:Follow') {
 353                                         ActivityPub\Processor::rejectFollowUser($object_data);
 354                                 }
 355                                 break;
 356
 357                         case 'as:Undo':
 358                                 if ($object_data['object_type'] == 'as:Follow') {
 359                                         ActivityPub\Processor::undoFollowUser($object_data);
 360                                 } elseif (in_array($object_data['object_type'], self::ACTIVITY_TYPES)) {
 361                                         ActivityPub\Processor::undoActivity($object_data);
 362                                 }
 363                                 break;
 364
 365                         default:
 366                                 logger('Unknown activity: ' . $type, LOGGER_DEBUG);
 367                                 break;
 368                 }
 369         }
 370
 371         /**
 372          * Fetch the receiver list from an activity array
 373          *
 374          * @param array $activity
 375          * @param string $actor
 376          *
 377          * @return array with receivers (user id)
 378          */
 379         private static function getReceivers($activity, $actor)
 380         {
 381                 $receivers = [];
 382
 383                 // When it is an answer, we inherite the receivers from the parent
 384                 $replyto = JsonLD::fetchElement($activity, 'as:inReplyTo');
 385                 if (!empty($replyto)) {
 386                         $parents = Item::select(['uid'], ['uri' => $replyto]);
 387                         while ($parent = Item::fetch($parents)) {
 388                                 $receivers['uid:' . $parent['uid']] = $parent['uid'];
 389                         }
 390                 }
 391
 392                 if (!empty($actor)) {
 393                         $profile = APContact::getByURL($actor);
 394                         $followers = defaults($profile, 'followers', '');
 395
 396                         logger('Actor: ' . $actor . ' - Followers: ' . $followers, LOGGER_DEBUG);
 397                 } else {
 398                         logger('Empty actor', LOGGER_DEBUG);
 399                         $followers = '';
 400                 }
 401
 402                 foreach (['as:to', 'as:cc', 'as:bto', 'as:bcc'] as $element) {
 403                         $receiver_list = JsonLD::fetchElementArray($activity, $element);
 404                         if (empty($receiver_list)) {
 405                                 continue;
 406                         }
 407
 408                         foreach ($receiver_list as $receiver) {
 409                                 if ($receiver == self::PUBLIC_COLLECTION) {
 410                                         $receivers['uid:0'] = 0;
 411                                 }
 412
 413                                 if (($receiver == self::PUBLIC_COLLECTION) && !empty($actor)) {
 414                                         // This will most likely catch all OStatus connections to Mastodon
 415                                         $condition = ['alias' => [$actor, normalise_link($actor)], 'rel' => [Contact::SHARING, Contact::FRIEND]
 416                                                 , 'archive' => false, 'pending' => false];
 417                                         $contacts = DBA::select('contact', ['uid'], $condition);
 418                                         while ($contact = DBA::fetch($contacts)) {
 419                                                 if ($contact['uid'] != 0) {
 420                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
 421                                                 }
 422                                         }
 423                                         DBA::close($contacts);
 424                                 }
 425
 426                                 if (in_array($receiver, [$followers, self::PUBLIC_COLLECTION]) && !empty($actor)) {
 427                                         $networks = [Protocol::ACTIVITYPUB, Protocol::DFRN, Protocol::DIASPORA, Protocol::OSTATUS];
 428                                         $condition = ['nurl' => normalise_link($actor), 'rel' => [Contact::SHARING, Contact::FRIEND],
 429                                                 'network' => $networks, 'archive' => false, 'pending' => false];
 430                                         $contacts = DBA::select('contact', ['uid'], $condition);
 431                                         while ($contact = DBA::fetch($contacts)) {
 432                                                 if ($contact['uid'] != 0) {
 433                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
 434                                                 }
 435                                         }
 436                                         DBA::close($contacts);
 437                                         continue;
 438                                 }
 439
 440                                 $condition = ['self' => true, 'nurl' => normalise_link($receiver)];
 441                                 $contact = DBA::selectFirst('contact', ['uid'], $condition);
 442                                 if (!DBA::isResult($contact)) {
 443                                         continue;
 444                                 }
 445                                 $receivers['uid:' . $contact['uid']] = $contact['uid'];
 446                         }
 447                 }
 448
 449                 self::switchContacts($receivers, $actor);
 450
 451                 return $receivers;
 452         }
 453
 454         /**
 455          * Switches existing contacts to ActivityPub
 456          *
 457          * @param integer $cid Contact ID
 458          * @param integer $uid User ID
 459          * @param string $url Profile URL
 460          */
 461         public static function switchContact($cid, $uid, $url)
 462         {
 463                 $profile = ActivityPub::probeProfile($url);
 464                 if (empty($profile)) {
 465                         return;
 466                 }
 467
 468                 logger('Switch contact ' . $cid . ' (' . $profile['url'] . ') for user ' . $uid . ' to ActivityPub');
 469
 470                 $photo = defaults($profile, 'photo', null);
 471                 unset($profile['photo']);
 472                 unset($profile['baseurl']);
 473
 474                 $profile['nurl'] = normalise_link($profile['url']);
 475                 DBA::update('contact', $profile, ['id' => $cid]);
 476
 477                 Contact::updateAvatar($photo, $uid, $cid);
 478
 479                 // Send a new follow request to be sure that the connection still exists
 480                 if (($uid != 0) && DBA::exists('contact', ['id' => $cid, 'rel' => [Contact::SHARING, Contact::FRIEND]])) {
 481                         ActivityPub\Transmitter::sendActivity('Follow', $profile['url'], $uid);
 482                         logger('Send a new follow request to ' . $profile['url'] . ' for user ' . $uid, LOGGER_DEBUG);
 483                 }
 484         }
 485
 486         /**
 487          *
 488          *
 489          * @param $receivers
 490          * @param $actor
 491          */
 492         private static function switchContacts($receivers, $actor)
 493         {
 494                 if (empty($actor)) {
 495                         return;
 496                 }
 497
 498                 foreach ($receivers as $receiver) {
 499                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver, 'network' => Protocol::OSTATUS, 'nurl' => normalise_link($actor)]);
 500                         if (DBA::isResult($contact)) {
 501                                 self::switchContact($contact['id'], $receiver, $actor);
 502                         }
 503
 504                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver, 'network' => Protocol::OSTATUS, 'alias' => [normalise_link($actor), $actor]]);
 505                         if (DBA::isResult($contact)) {
 506                                 self::switchContact($contact['id'], $receiver, $actor);
 507                         }
 508                 }
 509         }
 510
 511         /**
 512          *
 513          *
 514          * @param $object_data
 515          * @param array $activity
 516          *
 517          * @return
 518          */
 519         private static function addActivityFields($object_data, $activity)
 520         {
 521                 if (!empty($activity['published']) && empty($object_data['published'])) {
 522                         $object_data['published'] = JsonLD::fetchElement($activity, 'as:published', '@value');
 523                 }
 524
 525                 if (!empty($activity['diaspora:guid']) && empty($object_data['diaspora:guid'])) {
 526                         $object_data['diaspora:guid'] = JsonLD::fetchElement($activity, 'diaspora:guid');
 527                 }
 528
 529                 $object_data['service'] = JsonLD::fetchElement($activity, 'as:instrument', 'as:name', '@type', 'as:Service');
 530
 531                 return $object_data;
 532         }
 533
 534         /**
 535          * Fetches the object data from external ressources if needed
 536          *
 537          * @param string  $object_id    Object ID of the the provided object
 538          * @param array   $object       The provided object array
 539          * @param boolean $trust_source Do we trust the provided object?
 540          *
 541          * @return array with trusted and valid object data
 542          */
 543         private static function fetchObject($object_id, $object = [], $trust_source = false)
 544         {
 545                 // By fetching the type we check if the object is complete.
 546                 $type = JsonLD::fetchElement($object, '@type');
 547
 548                 if (!$trust_source || empty($type)) {
 549                         $data = ActivityPub::fetchContent($object_id);
 550                         if (!empty($data)) {
 551                                 $object = JsonLD::compact($data);
 552                                 logger('Fetched content for ' . $object_id, LOGGER_DEBUG);
 553                         } else {
 554                                 logger('Empty content for ' . $object_id . ', check if content is available locally.', LOGGER_DEBUG);
 555
 556                                 $item = Item::selectFirst([], ['uri' => $object_id]);
 557                                 if (!DBA::isResult($item)) {
 558                                         logger('Object with url ' . $object_id . ' was not found locally.', LOGGER_DEBUG);
 559                                         return false;
 560                                 }
 561                                 logger('Using already stored item for url ' . $object_id, LOGGER_DEBUG);
 562                                 $data = ActivityPub\Transmitter::createNote($item);
 563                                 $object = JsonLD::compact($data);
 564                         }
 565                 } else {
 566                         logger('Using original object for url ' . $object_id, LOGGER_DEBUG);
 567                 }
 568
 569                 $type = JsonLD::fetchElement($object, '@type');
 570
 571                 if (empty($type)) {
 572                         logger('Empty type', LOGGER_DEBUG);
 573                         return false;
 574                 }
 575
 576                 if (in_array($type, self::CONTENT_TYPES)) {
 577                         return self::processObject($object);
 578                 }
 579
 580                 if ($type == 'as:Announce') {
 581                         $object_id = JsonLD::fetchElement($object, 'object');
 582                         if (empty($object_id)) {
 583                                 return false;
 584                         }
 585                         return self::fetchObject($object_id);
 586                 }
 587
 588                 logger('Unhandled object type: ' . $type, LOGGER_DEBUG);
 589         }
 590
 591         /**
 592          * Convert tags from JSON-LD format into a simplified format
 593          *
 594          * @param array $tags Tags in JSON-LD format
 595          *
 596          * @return array with tags in a simplified format
 597          */
 598         private static function processTags($tags)
 599         {
 600                 $taglist = [];
 601
 602                 if (empty($tags)) {
 603                         return [];
 604                 }
 605
 606                 foreach ($tags as $tag) {
 607                         if (empty($tag)) {
 608                                 continue;
 609                         }
 610
 611                         $taglist[] = ['type' => str_replace('as:', '', JsonLD::fetchElement($tag, '@type')),
 612                                 'href' => JsonLD::fetchElement($tag, 'as:href'),
 613                                 'name' => JsonLD::fetchElement($tag, 'as:name')];
 614                 }
 615                 return $taglist;
 616         }
 617
 618         /**
 619          * Convert attachments from JSON-LD format into a simplified format
 620          *
 621          * @param array $attachments Attachments in JSON-LD format
 622          *
 623          * @return array with attachmants in a simplified format
 624          */
 625         private static function processAttachments($attachments)
 626         {
 627                 $attachlist = [];
 628
 629                 if (empty($attachments)) {
 630                         return [];
 631                 }
 632
 633                 foreach ($attachments as $attachment) {
 634                         if (empty($attachment)) {
 635                                 continue;
 636                         }
 637
 638                         $attachlist[] = ['type' => str_replace('as:', '', JsonLD::fetchElement($attachment, '@type')),
 639                                 'mediaType' => JsonLD::fetchElement($attachment, 'as:mediaType'),
 640                                 'name' => JsonLD::fetchElement($attachment, 'as:name'),
 641                                 'url' => JsonLD::fetchElement($attachment, 'as:url')];
 642                 }
 643                 return $attachlist;
 644         }
 645
 646         /**
 647          * Fetches data from the object part of an activity
 648          *
 649          * @param array $object
 650          *
 651          * @return array
 652          */
 653         private static function processObject($object)
 654         {
 655                 if (!JsonLD::fetchElement($object, '@id')) {
 656                         return false;
 657                 }
 658
 659                 $object_data = [];
 660                 $object_data['object_type'] = JsonLD::fetchElement($object, '@type');
 661                 $object_data['id'] = JsonLD::fetchElement($object, '@id');
 662
 663                 $object_data['reply-to-id'] = JsonLD::fetchElement($object, 'as:inReplyTo');
 664
 665                 if (empty($object_data['reply-to-id'])) {
 666                         $object_data['reply-to-id'] = $object_data['id'];
 667                 }
 668
 669                 $object_data['published'] = JsonLD::fetchElement($object, 'as:published', '@value');
 670                 $object_data['updated'] = JsonLD::fetchElement($object, 'as:updated', '@value');
 671
 672                 if (empty($object_data['updated'])) {
 673                         $object_data['updated'] = $object_data['published'];
 674                 }
 675
 676                 if (empty($object_data['published']) && !empty($object_data['updated'])) {
 677                         $object_data['published'] = $object_data['updated'];
 678                 }
 679
 680                 $actor = JsonLD::fetchElement($object, 'as:attributedTo');
 681                 if (empty($actor)) {
 682                         $actor = JsonLD::fetchElement($object, 'as:actor');
 683                 }
 684
 685                 $object_data['diaspora:guid'] = JsonLD::fetchElement($object, 'diaspora:guid');
 686                 $object_data['diaspora:comment'] = JsonLD::fetchElement($object, 'diaspora:comment');
 687                 $object_data['actor'] = $object_data['author'] = $actor;
 688                 $object_data['context'] = JsonLD::fetchElement($object, 'as:context');
 689                 $object_data['conversation'] = JsonLD::fetchElement($object, 'ostatus:conversation');
 690                 $object_data['sensitive'] = JsonLD::fetchElement($object, 'as:sensitive');
 691                 $object_data['name'] = JsonLD::fetchElement($object, 'as:name');
 692                 $object_data['summary'] = JsonLD::fetchElement($object, 'as:summary');
 693                 $object_data['content'] = JsonLD::fetchElement($object, 'as:content');
 694                 $object_data['source'] = JsonLD::fetchElement($object, 'as:source', 'as:content', 'as:mediaType', 'text/bbcode');
 695                 $object_data['start-time'] = JsonLD::fetchElement($object, 'as:startTime', '@value');
 696                 $object_data['end-time'] = JsonLD::fetchElement($object, 'as:endTime', '@value');
 697                 $object_data['location'] = JsonLD::fetchElement($object, 'as:location', 'as:name', '@type', 'as:Place');
 698                 $object_data['latitude'] = JsonLD::fetchElement($object, 'as:location', 'as:latitude', '@type', 'as:Place');
 699                 $object_data['latitude'] = JsonLD::fetchElement($object_data, 'latitude', '@value');
 700                 $object_data['longitude'] = JsonLD::fetchElement($object, 'as:location', 'as:longitude', '@type', 'as:Place');
 701                 $object_data['longitude'] = JsonLD::fetchElement($object_data, 'longitude', '@value');
 702                 $object_data['attachments'] = self::processAttachments(JsonLD::fetchElementArray($object, 'as:attachment'));
 703                 $object_data['tags'] = self::processTags(JsonLD::fetchElementArray($object, 'as:tag'));
 704                 $object_data['generator'] = JsonLD::fetchElement($object, 'as:generator', 'as:name', '@type', 'as:Application');
 705                 $object_data['alternate-url'] = JsonLD::fetchElement($object, 'as:url');
 706
 707                 // Special treatment for Hubzilla links
 708                 if (is_array($object_data['alternate-url'])) {
 709                         $object_data['alternate-url'] = JsonLD::fetchElement($object_data['alternate-url'], 'as:href');
 710
 711                         if (!is_string($object_data['alternate-url'])) {
 712                                 $object_data['alternate-url'] = JsonLD::fetchElement($object['as:url'], 'as:href');
 713                         }
 714                 }
 715
 716                 $object_data['receiver'] = self::getReceivers($object, $object_data['actor']);
 717
 718                 // Common object data:
 719
 720                 // Unhandled
 721                 // @context, type, actor, signature, mediaType, duration, replies, icon
 722
 723                 // Also missing: (Defined in the standard, but currently unused)
 724                 // audience, preview, endTime, startTime, image
 725
 726                 // Data in Notes:
 727
 728                 // Unhandled
 729                 // contentMap, announcement_count, announcements, context_id, likes, like_count
 730                 // inReplyToStatusId, shares, quoteUrl, statusnetConversationId
 731
 732                 // Data in video:
 733
 734                 // To-Do?
 735                 // category, licence, language, commentsEnabled
 736
 737                 // Unhandled
 738                 // views, waitTranscoding, state, support, subtitleLanguage
 739                 // likes, dislikes, shares, comments
 740
 741                 return $object_data;
 742         }
 743 }