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  * - Undo Announce
  25  *
  26  * Check what this is meant to do:
  27  * - Add
  28  * - Block
  29  * - Flag
  30  * - Remove
  31  * - Undo Block
  32  */
  33 class Receiver
  34 {
  35         const PUBLIC_COLLECTION = 'as:Public';
  36         const ACCOUNT_TYPES = ['as:Person', 'as:Organization', 'as:Service', 'as:Group', 'as:Application'];
  37         const CONTENT_TYPES = ['as:Note', 'as:Article', 'as:Video', 'as:Image', 'as:Event'];
  38         const ACTIVITY_TYPES = ['as:Like', 'as:Dislike', 'as:Accept', 'as:Reject', 'as:TentativeAccept'];
  39
  40         /**
  41          * Checks if the web request is done for the AP protocol
  42          *
  43          * @return is it AP?
  44          */
  45         public static function isRequest()
  46         {
  47                 return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
  48                         stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
  49         }
  50
  51         /**
  52          * Checks incoming message from the inbox
  53          *
  54          * @param $body
  55          * @param $header
  56          * @param integer $uid User ID
  57          */
  58         public static function processInbox($body, $header, $uid)
  59         {
  60                 $http_signer = HTTPSignature::getSigner($body, $header);
  61                 if (empty($http_signer)) {
  62                         logger('Invalid HTTP signature, message will be discarded.', LOGGER_DEBUG);
  63                         return;
  64                 } else {
  65                         logger('HTTP signature is signed by ' . $http_signer, LOGGER_DEBUG);
  66                 }
  67
  68                 $activity = json_decode($body, true);
  69
  70                 if (empty($activity)) {
  71                         logger('Invalid body.', LOGGER_DEBUG);
  72                         return;
  73                 }
  74
  75                 $ldactivity = JsonLD::compact($activity);
  76
  77                 $actor = JsonLD::fetchElement($ldactivity, 'as:actor');
  78
  79                 logger('Message for user ' . $uid . ' is from actor ' . $actor, LOGGER_DEBUG);
  80
  81                 if (LDSignature::isSigned($activity)) {
  82                         $ld_signer = LDSignature::getSigner($activity);
  83                         if (empty($ld_signer)) {
  84                                 logger('Invalid JSON-LD signature from ' . $actor, LOGGER_DEBUG);
  85                         }
  86                         if (!empty($ld_signer && ($actor == $http_signer))) {
  87                                 logger('The HTTP and the JSON-LD signature belong to ' . $ld_signer, LOGGER_DEBUG);
  88                                 $trust_source = true;
  89                         } elseif (!empty($ld_signer)) {
  90                                 logger('JSON-LD signature is signed by ' . $ld_signer, LOGGER_DEBUG);
  91                                 $trust_source = true;
  92                         } elseif ($actor == $http_signer) {
  93                                 logger('Bad JSON-LD signature, but HTTP signer fits the actor.', LOGGER_DEBUG);
  94                                 $trust_source = true;
  95                         } else {
  96                                 logger('Invalid JSON-LD signature and the HTTP signer is different.', LOGGER_DEBUG);
  97                                 $trust_source = false;
  98                         }
  99                 } elseif ($actor == $http_signer) {
 100                         logger('Trusting post without JSON-LD signature, The actor fits the HTTP signer.', LOGGER_DEBUG);
 101                         $trust_source = true;
 102                 } else {
 103                         logger('No JSON-LD signature, different actor.', LOGGER_DEBUG);
 104                         $trust_source = false;
 105                 }
 106
 107                 self::processActivity($ldactivity, $body, $uid, $trust_source);
 108         }
 109
 110         /**
 111          * Fetches the object type for a given object id
 112          *
 113          * @param array  $activity
 114          * @param string $object_id Object ID of the the provided object
 115          *
 116          * @return string with object type
 117          */
 118         private static function fetchObjectType($activity, $object_id)
 119         {
 120                 if (!empty($activity['as:object'])) {
 121                         $object_type = JsonLD::fetchElement($activity['as:object'], '@type');
 122                         if (!empty($object_type)) {
 123                                 return $object_type;
 124                         }
 125                 }
 126
 127                 if (Item::exists(['uri' => $object_id, 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT]])) {
 128                         // We just assume "note" since it doesn't make a difference for the further processing
 129                         return 'as:Note';
 130                 }
 131
 132                 $profile = APContact::getByURL($object_id);
 133                 if (!empty($profile['type'])) {
 134                         return 'as:' . $profile['type'];
 135                 }
 136
 137                 $data = ActivityPub::fetchContent($object_id);
 138                 if (!empty($data)) {
 139                         $object = JsonLD::compact($data);
 140                         $type = JsonLD::fetchElement($object, '@type');
 141                         if (!empty($type)) {
 142                                 return $type;
 143                         }
 144                 }
 145
 146                 return null;
 147         }
 148
 149         /**
 150          * Prepare the object array
 151          *
 152          * @param array $activity
 153          * @param integer $uid User ID
 154          * @param $trust_source
 155          *
 156          * @return array with object data
 157          */
 158         private static function prepareObjectData($activity, $uid, &$trust_source)
 159         {
 160                 $actor = JsonLD::fetchElement($activity, 'as:actor');
 161                 if (empty($actor)) {
 162                         logger('Empty actor', LOGGER_DEBUG);
 163                         return [];
 164                 }
 165
 166                 $type = JsonLD::fetchElement($activity, '@type');
 167
 168                 // Fetch all receivers from to, cc, bto and bcc
 169                 $receivers = self::getReceivers($activity, $actor);
 170
 171                 // When it is a delivery to a personal inbox we add that user to the receivers
 172                 if (!empty($uid)) {
 173                         $owner = User::getOwnerDataById($uid);
 174                         $additional = ['uid:' . $uid => $uid];
 175                         $receivers = array_merge($receivers, $additional);
 176                 }
 177
 178                 logger('Receivers: ' . json_encode($receivers), LOGGER_DEBUG);
 179
 180                 $object_id = JsonLD::fetchElement($activity, 'as:object');
 181                 if (empty($object_id)) {
 182                         logger('No object found', LOGGER_DEBUG);
 183                         return [];
 184                 }
 185
 186                 $object_type = self::fetchObjectType($activity, $object_id);
 187
 188                 // Fetch the content only on activities where this matters
 189                 if (in_array($type, ['as:Create', 'as:Update', 'as:Announce'])) {
 190                         if ($type == 'as:Announce') {
 191                                 $trust_source = false;
 192                         }
 193                         $object_data = self::fetchObject($object_id, $activity['as:object'], $trust_source);
 194                         if (empty($object_data)) {
 195                                 logger("Object data couldn't be processed", LOGGER_DEBUG);
 196                                 return [];
 197                         }
 198                         // We had been able to retrieve the object data - so we can trust the source
 199                         $trust_source = true;
 200                 } elseif (in_array($type, ['as:Like', 'as:Dislike'])) {
 201                         // Create a mostly empty array out of the activity data (instead of the object).
 202                         // This way we later don't have to check for the existence of ech individual array element.
 203                         $object_data = self::processObject($activity);
 204                         $object_data['name'] = $type;
 205                         $object_data['author'] = JsonLD::fetchElement($activity, 'as:actor');
 206                         $object_data['object_id'] = $object_id;
 207                         $object_data['object_type'] = ''; // Since we don't fetch the object, we don't know the type
 208                 } else {
 209                         $object_data = [];
 210                         $object_data['id'] = JsonLD::fetchElement($activity, '@id');
 211                         $object_data['object_id'] = JsonLD::fetchElement($activity, 'as:object');
 212                         $object_data['object_actor'] = JsonLD::fetchElement($activity['as:object'], 'as:actor');
 213                         $object_data['object_object'] = JsonLD::fetchElement($activity['as:object'], 'as:object');
 214                         $object_data['object_type'] = JsonLD::fetchElement($activity['as:object'], '@type');
 215
 216                         // An Undo is done on the object of an object, so we need that type as well
 217                         if ($type == 'as:Undo') {
 218                                 $object_data['object_object_type'] = self::fetchObjectType([], $object_data['object_object']);
 219                         }
 220                 }
 221
 222                 $object_data = self::addActivityFields($object_data, $activity);
 223
 224                 if (empty($object_data['object_type'])) {
 225                         $object_data['object_type'] = $object_type;
 226                 }
 227
 228                 $object_data['type'] = $type;
 229                 $object_data['actor'] = $actor;
 230                 $object_data['receiver'] = array_merge(defaults($object_data, 'receiver', []), $receivers);
 231
 232                 logger('Processing ' . $object_data['type'] . ' ' . $object_data['object_type'] . ' ' . $object_data['id'], LOGGER_DEBUG);
 233
 234                 return $object_data;
 235         }
 236
 237         /**
 238          * Store the unprocessed data into the conversation table
 239          * This has to be done outside the regular function,
 240          * since we store everything - not only item posts.
 241          *
 242          * @param array  $activity Array with activity data
 243          * @param string $body     The raw message
 244          */
 245         private static function storeConversation($activity, $body)
 246         {
 247                 if (empty($body) || empty($activity['id'])) {
 248                         return;
 249                 }
 250
 251                 $conversation = [
 252                         'protocol' => Conversation::PARCEL_ACTIVITYPUB,
 253                         'item-uri' => $activity['id'],
 254                         'reply-to-uri' => defaults($activity, 'reply-to-id', ''),
 255                         'conversation-href' => defaults($activity, 'context', ''),
 256                         'conversation-uri' => defaults($activity, 'conversation', ''),
 257                         'source' => $body,
 258                         'received' => DateTimeFormat::utcNow()];
 259
 260                 DBA::insert('conversation', $conversation, true);
 261         }
 262
 263         /**
 264          * Processes the activity object
 265          *
 266          * @param array   $activity     Array with activity data
 267          * @param string  $body
 268          * @param integer $uid          User ID
 269          * @param boolean $trust_source Do we trust the source?
 270          */
 271         public static function processActivity($activity, $body = '', $uid = null, $trust_source = false)
 272         {
 273                 $type = JsonLD::fetchElement($activity, '@type');
 274                 if (!$type) {
 275                         logger('Empty type', LOGGER_DEBUG);
 276                         return;
 277                 }
 278
 279                 if (!JsonLD::fetchElement($activity, 'as:object')) {
 280                         logger('Empty object', LOGGER_DEBUG);
 281                         return;
 282                 }
 283
 284                 if (!JsonLD::fetchElement($activity, 'as:actor')) {
 285                         logger('Empty actor', LOGGER_DEBUG);
 286                         return;
 287
 288                 }
 289
 290                 // $trust_source is called by reference and is set to true if the content was retrieved successfully
 291                 $object_data = self::prepareObjectData($activity, $uid, $trust_source);
 292                 if (empty($object_data)) {
 293                         logger('No object data found', LOGGER_DEBUG);
 294                         return;
 295                 }
 296
 297                 if (!$trust_source) {
 298                         logger('No trust for activity type "' . $type . '", so we quit now.', LOGGER_DEBUG);
 299                         return;
 300                 }
 301
 302                 self::storeConversation($object_data, $body);
 303
 304                 // Internal flag for thread completion. See Processor.php
 305                 if (!empty($activity['thread-completion'])) {
 306                         $object_data['thread-completion'] = $activity['thread-completion'];
 307                 }
 308
 309                 switch ($type) {
 310                         case 'as:Create':
 311                         case 'as:Announce':
 312                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 313                                         ActivityPub\Processor::createItem($object_data);
 314                                 }
 315                                 break;
 316
 317                         case 'as:Like':
 318                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 319                                         ActivityPub\Processor::createActivity($object_data, ACTIVITY_LIKE);
 320                                 }
 321                                 break;
 322
 323                         case 'as:Dislike':
 324                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 325                                         ActivityPub\Processor::createActivity($object_data, ACTIVITY_DISLIKE);
 326                                 }
 327                                 break;
 328
 329                         case 'as:TentativeAccept':
 330                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 331                                         ActivityPub\Processor::createActivity($object_data, ACTIVITY_ATTENDMAYBE);
 332                                 }
 333                                 break;
 334
 335                         case 'as:Update':
 336                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 337                                         ActivityPub\Processor::updateItem($object_data);
 338                                 } elseif (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 339                                         ActivityPub\Processor::updatePerson($object_data, $body);
 340                                 }
 341                                 break;
 342
 343                         case 'as:Delete':
 344                                 if ($object_data['object_type'] == 'as:Tombstone') {
 345                                         ActivityPub\Processor::deleteItem($object_data, $body);
 346                                 } elseif (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 347                                         ActivityPub\Processor::deletePerson($object_data, $body);
 348                                 }
 349                                 break;
 350
 351                         case 'as:Follow':
 352                                 if (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
 353                                         ActivityPub\Processor::followUser($object_data);
 354                                 }
 355                                 break;
 356
 357                         case 'as:Accept':
 358                                 if ($object_data['object_type'] == 'as:Follow') {
 359                                         ActivityPub\Processor::acceptFollowUser($object_data);
 360                                 } elseif (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 361                                         ActivityPub\Processor::createActivity($object_data, ACTIVITY_ATTEND);
 362                                 }
 363                                 break;
 364
 365                         case 'as:Reject':
 366                                 if ($object_data['object_type'] == 'as:Follow') {
 367                                         ActivityPub\Processor::rejectFollowUser($object_data);
 368                                 } elseif (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
 369                                         ActivityPub\Processor::createActivity($object_data, ACTIVITY_ATTENDNO);
 370                                 }
 371                                 break;
 372
 373                         case 'as:Undo':
 374                                 if (($object_data['object_type'] == 'as:Follow') &&
 375                                         in_array($object_data['object_object_type'], self::ACCOUNT_TYPES)) {
 376                                         ActivityPub\Processor::undoFollowUser($object_data);
 377                                 } elseif (($object_data['object_type'] == 'as:Accept') &&
 378                                         in_array($object_data['object_object_type'], self::ACCOUNT_TYPES)) {
 379                                         ActivityPub\Processor::rejectFollowUser($object_data);
 380                                 } elseif (in_array($object_data['object_type'], self::ACTIVITY_TYPES) &&
 381                                         in_array($object_data['object_object_type'], self::CONTENT_TYPES)) {
 382                                         ActivityPub\Processor::undoActivity($object_data);
 383                                 }
 384                                 break;
 385
 386                         default:
 387                                 logger('Unknown activity: ' . $type . ' ' . $object_data['object_type'], LOGGER_DEBUG);
 388                                 break;
 389                 }
 390         }
 391
 392         /**
 393          * Fetch the receiver list from an activity array
 394          *
 395          * @param array $activity
 396          * @param string $actor
 397          *
 398          * @return array with receivers (user id)
 399          */
 400         private static function getReceivers($activity, $actor)
 401         {
 402                 $receivers = [];
 403
 404                 // When it is an answer, we inherite the receivers from the parent
 405                 $replyto = JsonLD::fetchElement($activity, 'as:inReplyTo');
 406                 if (!empty($replyto)) {
 407                         $parents = Item::select(['uid'], ['uri' => $replyto]);
 408                         while ($parent = Item::fetch($parents)) {
 409                                 $receivers['uid:' . $parent['uid']] = $parent['uid'];
 410                         }
 411                 }
 412
 413                 if (!empty($actor)) {
 414                         $profile = APContact::getByURL($actor);
 415                         $followers = defaults($profile, 'followers', '');
 416
 417                         logger('Actor: ' . $actor . ' - Followers: ' . $followers, LOGGER_DEBUG);
 418                 } else {
 419                         logger('Empty actor', LOGGER_DEBUG);
 420                         $followers = '';
 421                 }
 422
 423                 foreach (['as:to', 'as:cc', 'as:bto', 'as:bcc'] as $element) {
 424                         $receiver_list = JsonLD::fetchElementArray($activity, $element);
 425                         if (empty($receiver_list)) {
 426                                 continue;
 427                         }
 428
 429                         foreach ($receiver_list as $receiver) {
 430                                 if ($receiver == self::PUBLIC_COLLECTION) {
 431                                         $receivers['uid:0'] = 0;
 432                                 }
 433
 434                                 if (($receiver == self::PUBLIC_COLLECTION) && !empty($actor)) {
 435                                         // This will most likely catch all OStatus connections to Mastodon
 436                                         $condition = ['alias' => [$actor, normalise_link($actor)], 'rel' => [Contact::SHARING, Contact::FRIEND]
 437                                                 , 'archive' => false, 'pending' => false];
 438                                         $contacts = DBA::select('contact', ['uid'], $condition);
 439                                         while ($contact = DBA::fetch($contacts)) {
 440                                                 if ($contact['uid'] != 0) {
 441                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
 442                                                 }
 443                                         }
 444                                         DBA::close($contacts);
 445                                 }
 446
 447                                 if (in_array($receiver, [$followers, self::PUBLIC_COLLECTION]) && !empty($actor)) {
 448                                         $networks = [Protocol::ACTIVITYPUB, Protocol::DFRN, Protocol::DIASPORA, Protocol::OSTATUS];
 449                                         $condition = ['nurl' => normalise_link($actor), 'rel' => [Contact::SHARING, Contact::FRIEND],
 450                                                 'network' => $networks, 'archive' => false, 'pending' => false];
 451                                         $contacts = DBA::select('contact', ['uid'], $condition);
 452                                         while ($contact = DBA::fetch($contacts)) {
 453                                                 if ($contact['uid'] != 0) {
 454                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
 455                                                 }
 456                                         }
 457                                         DBA::close($contacts);
 458                                         continue;
 459                                 }
 460
 461                                 $condition = ['self' => true, 'nurl' => normalise_link($receiver)];
 462                                 $contact = DBA::selectFirst('contact', ['uid'], $condition);
 463                                 if (!DBA::isResult($contact)) {
 464                                         continue;
 465                                 }
 466                                 $receivers['uid:' . $contact['uid']] = $contact['uid'];
 467                         }
 468                 }
 469
 470                 self::switchContacts($receivers, $actor);
 471
 472                 return $receivers;
 473         }
 474
 475         /**
 476          * Switches existing contacts to ActivityPub
 477          *
 478          * @param integer $cid Contact ID
 479          * @param integer $uid User ID
 480          * @param string $url Profile URL
 481          */
 482         public static function switchContact($cid, $uid, $url)
 483         {
 484                 $profile = ActivityPub::probeProfile($url);
 485                 if (empty($profile)) {
 486                         return;
 487                 }
 488
 489                 logger('Switch contact ' . $cid . ' (' . $profile['url'] . ') for user ' . $uid . ' to ActivityPub');
 490
 491                 $photo = defaults($profile, 'photo', null);
 492                 unset($profile['photo']);
 493                 unset($profile['baseurl']);
 494
 495                 $profile['nurl'] = normalise_link($profile['url']);
 496                 DBA::update('contact', $profile, ['id' => $cid]);
 497
 498                 Contact::updateAvatar($photo, $uid, $cid);
 499
 500                 // Send a new follow request to be sure that the connection still exists
 501                 if (($uid != 0) && DBA::exists('contact', ['id' => $cid, 'rel' => [Contact::SHARING, Contact::FRIEND]])) {
 502                         ActivityPub\Transmitter::sendActivity('Follow', $profile['url'], $uid);
 503                         logger('Send a new follow request to ' . $profile['url'] . ' for user ' . $uid, LOGGER_DEBUG);
 504                 }
 505         }
 506
 507         /**
 508          *
 509          *
 510          * @param $receivers
 511          * @param $actor
 512          */
 513         private static function switchContacts($receivers, $actor)
 514         {
 515                 if (empty($actor)) {
 516                         return;
 517                 }
 518
 519                 foreach ($receivers as $receiver) {
 520                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver, 'network' => Protocol::OSTATUS, 'nurl' => normalise_link($actor)]);
 521                         if (DBA::isResult($contact)) {
 522                                 self::switchContact($contact['id'], $receiver, $actor);
 523                         }
 524
 525                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver, 'network' => Protocol::OSTATUS, 'alias' => [normalise_link($actor), $actor]]);
 526                         if (DBA::isResult($contact)) {
 527                                 self::switchContact($contact['id'], $receiver, $actor);
 528                         }
 529                 }
 530         }
 531
 532         /**
 533          *
 534          *
 535          * @param $object_data
 536          * @param array $activity
 537          *
 538          * @return
 539          */
 540         private static function addActivityFields($object_data, $activity)
 541         {
 542                 if (!empty($activity['published']) && empty($object_data['published'])) {
 543                         $object_data['published'] = JsonLD::fetchElement($activity, 'as:published', '@value');
 544                 }
 545
 546                 if (!empty($activity['diaspora:guid']) && empty($object_data['diaspora:guid'])) {
 547                         $object_data['diaspora:guid'] = JsonLD::fetchElement($activity, 'diaspora:guid');
 548                 }
 549
 550                 $object_data['service'] = JsonLD::fetchElement($activity, 'as:instrument', 'as:name', '@type', 'as:Service');
 551
 552                 return $object_data;
 553         }
 554
 555         /**
 556          * Fetches the object data from external ressources if needed
 557          *
 558          * @param string  $object_id    Object ID of the the provided object
 559          * @param array   $object       The provided object array
 560          * @param boolean $trust_source Do we trust the provided object?
 561          *
 562          * @return array with trusted and valid object data
 563          */
 564         private static function fetchObject($object_id, $object = [], $trust_source = false)
 565         {
 566                 // By fetching the type we check if the object is complete.
 567                 $type = JsonLD::fetchElement($object, '@type');
 568
 569                 if (!$trust_source || empty($type)) {
 570                         $data = ActivityPub::fetchContent($object_id);
 571                         if (!empty($data)) {
 572                                 $object = JsonLD::compact($data);
 573                                 logger('Fetched content for ' . $object_id, LOGGER_DEBUG);
 574                         } else {
 575                                 logger('Empty content for ' . $object_id . ', check if content is available locally.', LOGGER_DEBUG);
 576
 577                                 $item = Item::selectFirst([], ['uri' => $object_id]);
 578                                 if (!DBA::isResult($item)) {
 579                                         logger('Object with url ' . $object_id . ' was not found locally.', LOGGER_DEBUG);
 580                                         return false;
 581                                 }
 582                                 logger('Using already stored item for url ' . $object_id, LOGGER_DEBUG);
 583                                 $data = ActivityPub\Transmitter::createNote($item);
 584                                 $object = JsonLD::compact($data);
 585                         }
 586                 } else {
 587                         logger('Using original object for url ' . $object_id, LOGGER_DEBUG);
 588                 }
 589
 590                 $type = JsonLD::fetchElement($object, '@type');
 591
 592                 if (empty($type)) {
 593                         logger('Empty type', LOGGER_DEBUG);
 594                         return false;
 595                 }
 596
 597                 if (in_array($type, self::CONTENT_TYPES)) {
 598                         return self::processObject($object);
 599                 }
 600
 601                 if ($type == 'as:Announce') {
 602                         $object_id = JsonLD::fetchElement($object, 'object');
 603                         if (empty($object_id)) {
 604                                 return false;
 605                         }
 606                         return self::fetchObject($object_id);
 607                 }
 608
 609                 logger('Unhandled object type: ' . $type, LOGGER_DEBUG);
 610         }
 611
 612         /**
 613          * Convert tags from JSON-LD format into a simplified format
 614          *
 615          * @param array $tags Tags in JSON-LD format
 616          *
 617          * @return array with tags in a simplified format
 618          */
 619         private static function processTags($tags)
 620         {
 621                 $taglist = [];
 622
 623                 if (empty($tags)) {
 624                         return [];
 625                 }
 626
 627                 foreach ($tags as $tag) {
 628                         if (empty($tag)) {
 629                                 continue;
 630                         }
 631
 632                         $taglist[] = ['type' => str_replace('as:', '', JsonLD::fetchElement($tag, '@type')),
 633                                 'href' => JsonLD::fetchElement($tag, 'as:href'),
 634                                 'name' => JsonLD::fetchElement($tag, 'as:name')];
 635                 }
 636                 return $taglist;
 637         }
 638
 639         /**
 640          * Convert attachments from JSON-LD format into a simplified format
 641          *
 642          * @param array $attachments Attachments in JSON-LD format
 643          *
 644          * @return array with attachmants in a simplified format
 645          */
 646         private static function processAttachments($attachments)
 647         {
 648                 $attachlist = [];
 649
 650                 if (empty($attachments)) {
 651                         return [];
 652                 }
 653
 654                 foreach ($attachments as $attachment) {
 655                         if (empty($attachment)) {
 656                                 continue;
 657                         }
 658
 659                         $attachlist[] = ['type' => str_replace('as:', '', JsonLD::fetchElement($attachment, '@type')),
 660                                 'mediaType' => JsonLD::fetchElement($attachment, 'as:mediaType'),
 661                                 'name' => JsonLD::fetchElement($attachment, 'as:name'),
 662                                 'url' => JsonLD::fetchElement($attachment, 'as:url')];
 663                 }
 664                 return $attachlist;
 665         }
 666
 667         /**
 668          * Fetches data from the object part of an activity
 669          *
 670          * @param array $object
 671          *
 672          * @return array
 673          */
 674         private static function processObject($object)
 675         {
 676                 if (!JsonLD::fetchElement($object, '@id')) {
 677                         return false;
 678                 }
 679
 680                 $object_data = [];
 681                 $object_data['object_type'] = JsonLD::fetchElement($object, '@type');
 682                 $object_data['id'] = JsonLD::fetchElement($object, '@id');
 683
 684                 $object_data['reply-to-id'] = JsonLD::fetchElement($object, 'as:inReplyTo');
 685
 686                 if (empty($object_data['reply-to-id'])) {
 687                         $object_data['reply-to-id'] = $object_data['id'];
 688                 }
 689
 690                 $object_data['published'] = JsonLD::fetchElement($object, 'as:published', '@value');
 691                 $object_data['updated'] = JsonLD::fetchElement($object, 'as:updated', '@value');
 692
 693                 if (empty($object_data['updated'])) {
 694                         $object_data['updated'] = $object_data['published'];
 695                 }
 696
 697                 if (empty($object_data['published']) && !empty($object_data['updated'])) {
 698                         $object_data['published'] = $object_data['updated'];
 699                 }
 700
 701                 $actor = JsonLD::fetchElement($object, 'as:attributedTo');
 702                 if (empty($actor)) {
 703                         $actor = JsonLD::fetchElement($object, 'as:actor');
 704                 }
 705
 706                 $object_data['diaspora:guid'] = JsonLD::fetchElement($object, 'diaspora:guid');
 707                 $object_data['diaspora:comment'] = JsonLD::fetchElement($object, 'diaspora:comment');
 708                 $object_data['actor'] = $object_data['author'] = $actor;
 709                 $object_data['context'] = JsonLD::fetchElement($object, 'as:context');
 710                 $object_data['conversation'] = JsonLD::fetchElement($object, 'ostatus:conversation');
 711                 $object_data['sensitive'] = JsonLD::fetchElement($object, 'as:sensitive');
 712                 $object_data['name'] = JsonLD::fetchElement($object, 'as:name');
 713                 $object_data['summary'] = JsonLD::fetchElement($object, 'as:summary');
 714                 $object_data['content'] = JsonLD::fetchElement($object, 'as:content');
 715                 $object_data['source'] = JsonLD::fetchElement($object, 'as:source', 'as:content', 'as:mediaType', 'text/bbcode');
 716                 $object_data['start-time'] = JsonLD::fetchElement($object, 'as:startTime', '@value');
 717                 $object_data['end-time'] = JsonLD::fetchElement($object, 'as:endTime', '@value');
 718                 $object_data['location'] = JsonLD::fetchElement($object, 'as:location', 'as:name', '@type', 'as:Place');
 719                 $object_data['latitude'] = JsonLD::fetchElement($object, 'as:location', 'as:latitude', '@type', 'as:Place');
 720                 $object_data['latitude'] = JsonLD::fetchElement($object_data, 'latitude', '@value');
 721                 $object_data['longitude'] = JsonLD::fetchElement($object, 'as:location', 'as:longitude', '@type', 'as:Place');
 722                 $object_data['longitude'] = JsonLD::fetchElement($object_data, 'longitude', '@value');
 723                 $object_data['attachments'] = self::processAttachments(JsonLD::fetchElementArray($object, 'as:attachment'));
 724                 $object_data['tags'] = self::processTags(JsonLD::fetchElementArray($object, 'as:tag'));
 725                 $object_data['generator'] = JsonLD::fetchElement($object, 'as:generator', 'as:name', '@type', 'as:Application');
 726                 $object_data['alternate-url'] = JsonLD::fetchElement($object, 'as:url');
 727
 728                 // Special treatment for Hubzilla links
 729                 if (is_array($object_data['alternate-url'])) {
 730                         $object_data['alternate-url'] = JsonLD::fetchElement($object_data['alternate-url'], 'as:href');
 731
 732                         if (!is_string($object_data['alternate-url'])) {
 733                                 $object_data['alternate-url'] = JsonLD::fetchElement($object['as:url'], 'as:href');
 734                         }
 735                 }
 736
 737                 $object_data['receiver'] = self::getReceivers($object, $object_data['actor']);
 738
 739                 // Common object data:
 740
 741                 // Unhandled
 742                 // @context, type, actor, signature, mediaType, duration, replies, icon
 743
 744                 // Also missing: (Defined in the standard, but currently unused)
 745                 // audience, preview, endTime, startTime, image
 746
 747                 // Data in Notes:
 748
 749                 // Unhandled
 750                 // contentMap, announcement_count, announcements, context_id, likes, like_count
 751                 // inReplyToStatusId, shares, quoteUrl, statusnetConversationId
 752
 753                 // Data in video:
 754
 755                 // To-Do?
 756                 // category, licence, language, commentsEnabled
 757
 758                 // Unhandled
 759                 // views, waitTranscoding, state, support, subtitleLanguage
 760                 // likes, dislikes, shares, comments
 761
 762                 return $object_data;
 763         }
 764 }