src/Protocol/ActivityPub/Receiver.php

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