src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2023, 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\Content\Text\HTML;
  26 use Friendica\Content\Text\Markdown;
  27 use Friendica\Core\Cache\Enum\Duration;
  28 use Friendica\Core\Logger;
  29 use Friendica\Core\Protocol;
  30 use Friendica\Core\System;
  31 use Friendica\Core\Worker;
  32 use Friendica\Database\DBA;
  33 use Friendica\DI;
  34 use Friendica\Model\APContact;
  35 use Friendica\Model\Contact;
  36 use Friendica\Model\Conversation;
  37 use Friendica\Model\Event;
  38 use Friendica\Model\GServer;
  39 use Friendica\Model\Item;
  40 use Friendica\Model\ItemURI;
  41 use Friendica\Model\Mail;
  42 use Friendica\Model\Tag;
  43 use Friendica\Model\User;
  44 use Friendica\Model\Post;
  45 use Friendica\Protocol\Activity;
  46 use Friendica\Protocol\ActivityPub;
  47 use Friendica\Protocol\Delivery;
  48 use Friendica\Protocol\Relay;
  49 use Friendica\Util\DateTimeFormat;
  50 use Friendica\Util\HTTPSignature;
  51 use Friendica\Util\JsonLD;
  52 use Friendica\Util\Network;
  53 use Friendica\Util\Strings;
  54
  55 /**
  56  * ActivityPub Processor Protocol class
  57  */
  58 class Processor
  59 {
  60         const CACHEKEY_FETCH_ACTIVITY = 'processor:fetchMissingActivity:';
  61         const CACHEKEY_JUST_FETCHED   = 'processor:isJustFetched:';
  62
  63         /**
  64          * Add an object id to the list of processed ids
  65          *
  66          * @param string $id
  67          *
  68          * @return void
  69          */
  70         private static function addActivityId(string $id)
  71         {
  72                 DBA::delete('fetched-activity', ["`received` < ?", DateTimeFormat::utc('now - 5 minutes')]);
  73                 DBA::insert('fetched-activity', ['object-id' => $id, 'received' => DateTimeFormat::utcNow()]);
  74         }
  75
  76         /**
  77          * Checks if the given object id has just been fetched
  78          *
  79          * @param string $id
  80          *
  81          * @return boolean
  82          */
  83         private static function isFetched(string $id): bool
  84         {
  85                 return DBA::exists('fetched-activity', ['object-id' => $id]);
  86         }
  87
  88         /**
  89          * Extracts the tag character (#, @, !) from mention links
  90          *
  91          * @param string $body
  92          * @return string
  93          */
  94         public static function normalizeMentionLinks(string $body): string
  95         {
  96                 $body = preg_replace('%\[url=([^\[\]]*)]([#@!])(.*?)\[/url]%ism', '$2[url=$1]$3[/url]', $body);
  97                 $body = preg_replace('%([#@!])\[zrl=([^\[\]]*)](.*?)\[/zrl]%ism', '$1[url=$2]$3[/url]', $body);
  98                 return $body;
  99         }
 100
 101         /**
 102          * Convert the language array into a language JSON
 103          *
 104          * @param array $languages
 105          * @return string language JSON
 106          */
 107         private static function processLanguages(array $languages): string
 108         {
 109                 $codes = array_keys($languages);
 110                 $lang = [];
 111                 foreach ($codes as $code) {
 112                         $lang[$code] = 1;
 113                 }
 114
 115                 if (empty($lang)) {
 116                         return '';
 117                 }
 118
 119                 return json_encode($lang);
 120         }
 121         /**
 122          * Replaces emojis in the body
 123          *
 124          * @param int $uri_id
 125          * @param string $body
 126          * @param array $emojis
 127          *
 128          * @return string with replaced emojis
 129          */
 130         private static function replaceEmojis(int $uri_id, string $body, array $emojis): string
 131         {
 132                 $body = strtr($body,
 133                         array_combine(
 134                                 array_column($emojis, 'name'),
 135                                 array_map(function ($emoji) {
 136                                         return '[emoji=' . $emoji['href'] . ']' . $emoji['name'] . '[/emoji]';
 137                                 }, $emojis)
 138                         )
 139                 );
 140
 141                 // We store the emoji here to be able to avoid storing it in the media
 142                 foreach ($emojis as $emoji) {
 143                         Post\Link::getByLink($uri_id, $emoji['href']);
 144                 }
 145                 return $body;
 146         }
 147
 148         /**
 149          * Store attached media files in the post-media table
 150          *
 151          * @param int $uriid
 152          * @param array $attachment
 153          * @return void
 154          */
 155         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
 156         {
 157                 if (empty($attachment['url'])) {
 158                         return;
 159                 }
 160
 161                 $data = ['uri-id' => $uriid];
 162                 $data['type'] = Post\Media::UNKNOWN;
 163                 $data['url'] = $attachment['url'];
 164                 $data['mimetype'] = $attachment['mediaType'] ?? null;
 165                 $data['height'] = $attachment['height'] ?? null;
 166                 $data['width'] = $attachment['width'] ?? null;
 167                 $data['size'] = $attachment['size'] ?? null;
 168                 $data['preview'] = $attachment['image'] ?? null;
 169                 $data['description'] = $attachment['name'] ?? null;
 170
 171                 Post\Media::insert($data);
 172         }
 173
 174         /**
 175          * Store attachment data
 176          *
 177          * @param array   $activity
 178          * @param array   $item
 179          */
 180         private static function storeAttachments(array $activity, array $item)
 181         {
 182                 if (empty($activity['attachments'])) {
 183                         return;
 184                 }
 185
 186                 foreach ($activity['attachments'] as $attach) {
 187                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 188                 }
 189         }
 190
 191         /**
 192          * Store question data
 193          *
 194          * @param array   $activity
 195          * @param array   $item
 196          */
 197         private static function storeQuestion(array $activity, array $item)
 198         {
 199                 if (empty($activity['question'])) {
 200                         return;
 201                 }
 202                 $question = ['multiple' => $activity['question']['multiple']];
 203
 204                 if (!empty($activity['question']['voters'])) {
 205                         $question['voters'] = $activity['question']['voters'];
 206                 }
 207
 208                 if (!empty($activity['question']['end-time'])) {
 209                         $question['end-time'] = DateTimeFormat::utc($activity['question']['end-time']);
 210                 }
 211
 212                 Post\Question::update($item['uri-id'], $question);
 213
 214                 foreach ($activity['question']['options'] as $key => $option) {
 215                         $option = ['name' => $option['name'], 'replies' => $option['replies']];
 216                         Post\QuestionOption::update($item['uri-id'], $key, $option);
 217                 }
 218
 219                 Logger::debug('Storing incoming question', ['type' => $activity['type'], 'uri-id' => $item['uri-id'], 'question' => $activity['question']]);
 220         }
 221
 222         /**
 223          * Updates a message
 224          *
 225          * @param array      $activity   Activity array
 226          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 227          * @throws \ImagickException
 228          */
 229         public static function updateItem(array $activity)
 230         {
 231                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type', 'private'], ['uri' => $activity['id']]);
 232                 if (!DBA::isResult($item)) {
 233                         Logger::notice('No existing item, item will be created', ['uri' => $activity['id']]);
 234                         $item = self::createItem($activity, false);
 235                         if (empty($item)) {
 236                                 Queue::remove($activity);
 237                                 return;
 238                         }
 239
 240                         self::postItem($activity, $item);
 241                         return;
 242                 }
 243
 244                 $item['changed'] = DateTimeFormat::utcNow();
 245                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 246
 247                 Post\Media::deleteByURIId($item['uri-id'], [Post\Media::AUDIO, Post\Media::VIDEO, Post\Media::IMAGE, Post\Media::HTML]);
 248                 $item = self::processContent($activity, $item);
 249                 if (empty($item)) {
 250                         Queue::remove($activity);
 251                         return;
 252                 }
 253
 254                 self::storeAttachments($activity, $item);
 255                 self::storeQuestion($activity, $item);
 256
 257                 Post\History::add($item['uri-id'], $item);
 258                 Item::update($item, ['uri' => $activity['id']]);
 259
 260                 Queue::remove($activity);
 261
 262                 if ($activity['object_type'] == 'as:Event') {
 263                         $posts = Post::select(['event-id', 'uid'], ["`uri` = ? AND `event-id` > ?", $activity['id'], 0]);
 264                         while ($post = DBA::fetch($posts)) {
 265                                 self::updateEvent($post['event-id'], $activity);
 266                         }
 267                 }
 268         }
 269
 270         /**
 271          * Update an existing event
 272          *
 273          * @param int $event_id
 274          * @param array $activity
 275          */
 276         private static function updateEvent(int $event_id, array $activity)
 277         {
 278                 $event = DBA::selectFirst('event', [], ['id' => $event_id]);
 279
 280                 $event['edited']   = DateTimeFormat::utc($activity['updated']);
 281                 $event['summary']  = HTML::toBBCode($activity['name']);
 282                 $event['desc']     = HTML::toBBCode($activity['content']);
 283                 if (!empty($activity['start-time'])) {
 284                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 285                 }
 286                 if (!empty($activity['end-time'])) {
 287                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 288                 }
 289                 $event['nofinish'] = empty($event['finish']);
 290                 $event['location'] = $activity['location'];
 291
 292                 Logger::info('Updating event', ['uri' => $activity['id'], 'id' => $event_id]);
 293                 Event::store($event);
 294         }
 295
 296         /**
 297          * Prepares data for a message
 298          *
 299          * @param array $activity      Activity array
 300          * @param bool  $fetch_parents
 301          *
 302          * @return array Internal item
 303          *
 304          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 305          * @throws \ImagickException
 306          */
 307         public static function createItem(array $activity, bool $fetch_parents): array
 308         {
 309                 $item = [];
 310                 $item['verb'] = Activity::POST;
 311                 $item['thr-parent'] = $activity['reply-to-id'];
 312
 313                 if ($activity['reply-to-id'] == $activity['id']) {
 314                         $item['gravity'] = Item::GRAVITY_PARENT;
 315                         $item['object-type'] = Activity\ObjectType::NOTE;
 316                 } else {
 317                         $item['gravity'] = Item::GRAVITY_COMMENT;
 318                         $item['object-type'] = Activity\ObjectType::COMMENT;
 319                 }
 320
 321                 if (!empty($activity['conversation'])) {
 322                         $item['conversation'] = $activity['conversation'];
 323                 } elseif (!empty($activity['context'])) {
 324                         $item['conversation'] = $activity['context'];
 325                 }
 326
 327                 if (!empty($item['conversation'])) {
 328                         $conversation = Post::selectFirstThread(['uri'], ['conversation' => $item['conversation']]);
 329                         if (!empty($conversation)) {
 330                                 Logger::debug('Got conversation', ['conversation' => $item['conversation'], 'parent' => $conversation]);
 331                                 $item['parent-uri'] = $conversation['uri'];
 332                                 $item['parent-uri-id'] = ItemURI::getIdByURI($item['parent-uri']);
 333                         }
 334                 } else {
 335                         $conversation = [];
 336                 }
 337
 338                 Logger::debug('Create Item', ['id' => $activity['id'], 'conversation' => $item['conversation'] ?? '']);
 339                 if (empty($activity['author']) && empty($activity['actor'])) {
 340                         Logger::notice('Missing author and actor. We quit here.', ['activity' => $activity]);
 341                         Queue::remove($activity);
 342                         return [];
 343                 }
 344
 345                 if (!in_array(0, $activity['receiver']) || !DI::config()->get('system', 'fetch_parents')) {
 346                         $fetch_parents = false;
 347                 }
 348
 349                 if ($fetch_parents && empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 350                         $result = self::fetchParent($activity, !empty($conversation));
 351                         if (!empty($result)) {
 352                                 if (($item['thr-parent'] != $result) && Post::exists(['uri' => $result])) {
 353                                         $item['thr-parent'] = $result;
 354                                 }
 355                         } elseif (empty($conversation)) {
 356                                 return [];
 357                         }
 358                 }
 359
 360                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 361
 362                 if (empty($conversation) && empty($activity['directmessage']) && ($item['gravity'] != Item::GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 363                         Logger::notice('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 364                         if (!$fetch_parents) {
 365                                 Queue::remove($activity);
 366                         }
 367                         return [];
 368                 }
 369
 370                 $item['network'] = Protocol::ACTIVITYPUB;
 371                 $item['author-link'] = $activity['author'];
 372                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 373                 $item['owner-link'] = $activity['actor'];
 374                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 375
 376                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 377                         $item['private'] = Item::UNLISTED;
 378                 } elseif (in_array(0, $activity['receiver'])) {
 379                         $item['private'] = Item::PUBLIC;
 380                 } else {
 381                         $item['private'] = Item::PRIVATE;
 382                 }
 383
 384                 if (!empty($activity['raw'])) {
 385                         $item['source'] = $activity['raw'];
 386                 }
 387
 388                 $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 389
 390                 if (isset($activity['push'])) {
 391                         $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 392                 }
 393
 394                 if (!empty($activity['from-relay'])) {
 395                         $item['direction'] = Conversation::RELAY;
 396                 }
 397
 398                 if ($activity['object_type'] == 'as:Article') {
 399                         $item['post-type'] = Item::PT_ARTICLE;
 400                 } elseif ($activity['object_type'] == 'as:Audio') {
 401                         $item['post-type'] = Item::PT_AUDIO;
 402                 } elseif ($activity['object_type'] == 'as:Document') {
 403                         $item['post-type'] = Item::PT_DOCUMENT;
 404                 } elseif ($activity['object_type'] == 'as:Event') {
 405                         $item['post-type'] = Item::PT_EVENT;
 406                 } elseif ($activity['object_type'] == 'as:Image') {
 407                         $item['post-type'] = Item::PT_IMAGE;
 408                 } elseif ($activity['object_type'] == 'as:Page') {
 409                         $item['post-type'] = Item::PT_PAGE;
 410                 } elseif ($activity['object_type'] == 'as:Question') {
 411                         $item['post-type'] = Item::PT_POLL;
 412                 } elseif ($activity['object_type'] == 'as:Video') {
 413                         $item['post-type'] = Item::PT_VIDEO;
 414                 } else {
 415                         $item['post-type'] = Item::PT_NOTE;
 416                 }
 417
 418                 $item['isForum'] = false;
 419
 420                 if (!empty($activity['thread-completion'])) {
 421                         if ($activity['thread-completion'] != $item['owner-id']) {
 422                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 423                                 $item['causer-link'] = $actor['url'];
 424                                 $item['causer-id'] = $activity['thread-completion'];
 425                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 426                         } else {
 427                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 428                                 $item['causer-link'] = $item['owner-link'];
 429                                 $item['causer-id']   = $item['owner-id'];
 430                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 431                         }
 432
 433                         $item['owner-link'] = $item['author-link'];
 434                         $item['owner-id'] = $item['author-id'];
 435                 } else {
 436                         $actor = APContact::getByURL($item['owner-link'], false);
 437                         $item['isForum'] = ($actor['type'] ?? 'Person') == 'Group';
 438                 }
 439
 440                 $item['uri'] = $activity['id'];
 441
 442                 if (empty($activity['published']) || empty($activity['updated'])) {
 443                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 444                 }
 445
 446                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 447                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 448                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 449                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 450
 451                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 452                 if (empty($item['uri-id'])) {
 453                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 454                         return [];
 455                 }
 456
 457                 $item['thr-parent-id'] = ItemURI::getIdByURI($item['thr-parent']);
 458
 459                 $item = self::processContent($activity, $item);
 460                 if (empty($item)) {
 461                         Logger::info('Message was not processed');
 462                         Queue::remove($activity);
 463                         return [];
 464                 }
 465
 466                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 467
 468                 self::storeAttachments($activity, $item);
 469                 self::storeQuestion($activity, $item);
 470
 471                 // We received the post via AP, so we set the protocol of the server to AP
 472                 $contact = Contact::getById($item['author-id'], ['gsid']);
 473                 if (!empty($contact['gsid'])) {
 474                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 475                 }
 476
 477                 if ($item['author-id'] != $item['owner-id']) {
 478                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 479                         if (!empty($contact['gsid'])) {
 480                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 481                         }
 482                 }
 483
 484                 return $item;
 485         }
 486
 487         /**
 488          * Fetch and process parent posts for the given activity
 489          *
 490          * @param array $activity
 491          * @param bool  $in_background
 492          *
 493          * @return string
 494          */
 495         private static function fetchParent(array $activity, bool $in_background = false): string
 496         {
 497                 if (self::isFetched($activity['reply-to-id'])) {
 498                         Logger::info('Id is already fetched', ['id' => $activity['reply-to-id']]);
 499                         return '';
 500                 }
 501
 502                 self::addActivityId($activity['reply-to-id']);
 503
 504                 if (!DI::config()->get('system', 'fetch_by_worker')) {
 505                         $in_background = false;
 506                 }
 507
 508                 $recursion_depth = $activity['recursion-depth'] ?? 0;
 509
 510                 if (!$in_background && ($recursion_depth < DI::config()->get('system', 'max_recursion_depth'))) {
 511                         Logger::info('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 512                         $result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 513                         if (empty($result) && self::isActivityGone($activity['reply-to-id'])) {
 514                                 Logger::notice('The activity is gone, the queue entry will be deleted', ['parent' => $activity['reply-to-id']]);
 515                                 if (!empty($activity['entry-id'])) {
 516                                         Queue::deleteById($activity['entry-id']);
 517                                 }
 518                                 return '';
 519                         } elseif (!empty($result)) {
 520                                 $exists = Post::exists(['uri' => [$result, $activity['reply-to-id']]]);
 521                                 if ($exists) {
 522                                         Logger::info('The activity has been fetched and created.', ['parent' => $result]);
 523                                         return $result;
 524                                 } elseif (DI::config()->get('system', 'fetch_by_worker') || DI::config()->get('system', 'decoupled_receiver')) {
 525                                         Logger::info('The activity has been fetched and will hopefully be created later.', ['parent' => $result]);
 526                                 } else {
 527                                         Logger::notice('The activity exists but has not been created, the queue entry will be deleted.', ['parent' => $result]);
 528                                         if (!empty($activity['entry-id'])) {
 529                                                 Queue::deleteById($activity['entry-id']);
 530                                         }
 531                                 }
 532                                 return '';
 533                         }
 534                         if (empty($result) && !DI::config()->get('system', 'fetch_by_worker')) {
 535                                 return '';
 536                         }
 537                 } elseif (self::isActivityGone($activity['reply-to-id'])) {
 538                         Logger::notice('The activity is gone. We will not spawn a worker. The queue entry will be deleted', ['parent' => $activity['reply-to-id']]);
 539                         if ($in_background) {
 540                                 // fetching in background is done for all activities where we have got the conversation
 541                                 // There we only delete the single activity and not the whole thread since we can store the
 542                                 // other posts in the thread even with missing posts.
 543                                 Queue::remove($activity);
 544                         } elseif (!empty($activity['entry-id'])) {
 545                                 Queue::deleteById($activity['entry-id']);
 546                         }
 547                         return '';
 548                 } elseif ($in_background) {
 549                         Logger::notice('Fetching is done in the background.', ['parent' => $activity['reply-to-id']]);
 550                 } else {
 551                         Logger::notice('Recursion level is too high.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 552                 }
 553
 554                 if (!Fetch::hasWorker($activity['reply-to-id'])) {
 555                         Logger::notice('Fetching is done by worker.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 556                         Fetch::add($activity['reply-to-id']);
 557                         $activity['recursion-depth'] = 0;
 558                         $wid = Worker::add(Worker::PRIORITY_HIGH, 'FetchMissingActivity', $activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 559                         Fetch::setWorkerId($activity['reply-to-id'], $wid);
 560                 } else {
 561                         Logger::debug('Activity will already be fetched via a worker.', ['url' => $activity['reply-to-id']]);
 562                 }
 563
 564                 return '';
 565         }
 566
 567         /**
 568          * Check if a given activity is no longer available
 569          *
 570          * @param string $url
 571          *
 572          * @return boolean
 573          */
 574         public static function isActivityGone(string $url): bool
 575         {
 576                 try {
 577                         $curlResult = HTTPSignature::fetchRaw($url, 0);
 578                 } catch (\Exception $exception) {
 579                         Logger::notice('Error fetching url', ['url' => $url, 'exception' => $exception]);
 580                         return true;
 581                 }
 582
 583                 if (Network::isUrlBlocked($url)) {
 584                         return true;
 585                 }
 586
 587                 // @todo To ensure that the remote system is working correctly, we can check if the "Content-Type" contains JSON
 588                 if (in_array($curlResult->getReturnCode(), [401, 404])) {
 589                         return true;
 590                 }
 591
 592                 if ($curlResult->isSuccess()) {
 593                         $object = json_decode($curlResult->getBody(), true);
 594                         if (!empty($object)) {
 595                                 $activity = JsonLD::compact($object);
 596                                 if (JsonLD::fetchElement($activity, '@type') == 'as:Tombstone') {
 597                                         return true;
 598                                 }
 599                         }
 600                 } elseif ($curlResult->getReturnCode() == 0) {
 601                         $host = parse_url($url, PHP_URL_HOST);
 602                         if (!(filter_var($host, FILTER_VALIDATE_IP) || @dns_get_record($host . '.', DNS_A + DNS_AAAA))) {
 603                                 return true;
 604                         }
 605                 }
 606
 607                 return false;
 608         }
 609         /**
 610          * Delete items
 611          *
 612          * @param array $activity
 613          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 614          * @throws \ImagickException
 615          */
 616         public static function deleteItem(array $activity)
 617         {
 618                 $owner = Contact::getIdForURL($activity['actor']);
 619
 620                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 621                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 622                 Queue::remove($activity);
 623         }
 624
 625         /**
 626          * Prepare the item array for an activity
 627          *
 628          * @param array $activity Activity array
 629          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 630          * @throws \ImagickException
 631          */
 632         public static function addTag(array $activity)
 633         {
 634                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 635                         return;
 636                 }
 637
 638                 foreach ($activity['receiver'] as $receiver) {
 639                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 640                         if (!DBA::isResult($item)) {
 641                                 // We don't fetch missing content for this purpose
 642                                 continue;
 643                         }
 644
 645                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 646                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 647                                 continue;
 648                         }
 649
 650                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 651                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 652                 }
 653         }
 654
 655         /**
 656          * Prepare the item array for an activity
 657          *
 658          * @param array      $activity   Activity array
 659          * @param string     $verb       Activity verb
 660          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 661          * @throws \ImagickException
 662          */
 663         public static function createActivity(array $activity, string $verb)
 664         {
 665                 $activity['reply-to-id'] = $activity['object_id'];
 666                 $item = self::createItem($activity, false);
 667                 if (empty($item)) {
 668                         Logger::debug('Activity was not prepared', ['id' => $activity['object_id']]);
 669                         return;
 670                 }
 671
 672                 $item['verb'] = $verb;
 673                 $item['thr-parent'] = $activity['object_id'];
 674                 $item['gravity'] = Item::GRAVITY_ACTIVITY;
 675                 unset($item['post-type']);
 676                 $item['object-type'] = Activity\ObjectType::NOTE;
 677
 678                 if (!empty($activity['content'])) {
 679                         $item['body'] = HTML::toBBCode($activity['content']);
 680                 }
 681
 682                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 683
 684                 self::postItem($activity, $item);
 685         }
 686
 687         /**
 688          * Fetch the Uri-Id of a post for the "featured" collection
 689          *
 690          * @param array $activity
 691          * @return null|array
 692          */
 693         private static function getUriIdForFeaturedCollection(array $activity)
 694         {
 695                 $actor = APContact::getByURL($activity['actor']);
 696                 if (empty($actor)) {
 697                         return null;
 698                 }
 699
 700                 // Refetch the account when the "featured" collection is missing.
 701                 // This can be removed in a future version (end of 2022 should be good).
 702                 if (empty($actor['featured'])) {
 703                         $actor = APContact::getByURL($activity['actor'], true);
 704                         if (empty($actor)) {
 705                                 return null;
 706                         }
 707                 }
 708
 709                 $parent = Post::selectFirst(['uri-id', 'author-id'], ['uri' => $activity['object_id']]);
 710                 if (empty($parent['uri-id'])) {
 711                         if (self::fetchMissingActivity($activity['object_id'], $activity, '', Receiver::COMPLETION_AUTO)) {
 712                                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 713                         }
 714                 }
 715
 716                 if (!empty($parent['uri-id'])) {
 717                         $parent;
 718                 }
 719
 720                 return null;
 721         }
 722
 723         /**
 724          * Add a post to the "Featured" collection
 725          *
 726          * @param array $activity
 727          */
 728         public static function addToFeaturedCollection(array $activity)
 729         {
 730                 $post = self::getUriIdForFeaturedCollection($activity);
 731                 if (empty($post)) {
 732                         return;
 733                 }
 734
 735                 Logger::debug('Add post to featured collection', ['post' => $post]);
 736
 737                 Post\Collection::add($post['uri-id'], Post\Collection::FEATURED, $post['author-id']);
 738                 Queue::remove($activity);
 739         }
 740
 741         /**
 742          * Remove a post to the "Featured" collection
 743          *
 744          * @param array $activity
 745          */
 746         public static function removeFromFeaturedCollection(array $activity)
 747         {
 748                 $post = self::getUriIdForFeaturedCollection($activity);
 749                 if (empty($post)) {
 750                         return;
 751                 }
 752
 753                 Logger::debug('Remove post from featured collection', ['post' => $post]);
 754
 755                 Post\Collection::remove($post['uri-id'], Post\Collection::FEATURED);
 756                 Queue::remove($activity);
 757         }
 758
 759         /**
 760          * Create an event
 761          *
 762          * @param array $activity Activity array
 763          * @param array $item
 764          *
 765          * @return int event id
 766          * @throws \Exception
 767          */
 768         public static function createEvent(array $activity, array $item): int
 769         {
 770                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 771                 $event['desc']      = HTML::toBBCode($activity['content'] ?? '');
 772                 if (!empty($activity['start-time'])) {
 773                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 774                 }
 775                 if (!empty($activity['end-time'])) {
 776                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 777                 }
 778                 $event['nofinish']  = empty($event['finish']);
 779                 $event['location']  = $activity['location'];
 780                 $event['cid']       = $item['contact-id'];
 781                 $event['uid']       = $item['uid'];
 782                 $event['uri']       = $item['uri'];
 783                 $event['edited']    = $item['edited'];
 784                 $event['private']   = $item['private'];
 785                 $event['guid']      = $item['guid'];
 786                 $event['plink']     = $item['plink'];
 787                 $event['network']   = $item['network'];
 788                 $event['protocol']  = $item['protocol'];
 789                 $event['direction'] = $item['direction'];
 790                 $event['source']    = $item['source'];
 791
 792                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 793                 if (DBA::isResult($ev)) {
 794                         $event['id'] = $ev['id'];
 795                 }
 796
 797                 $event_id = Event::store($event);
 798
 799                 Logger::info('Event was stored', ['id' => $event_id]);
 800
 801                 return $event_id;
 802         }
 803
 804         /**
 805          * Process the content
 806          *
 807          * @param array $activity Activity array
 808          * @param array $item
 809          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 810          * @throws \Exception
 811          */
 812         private static function processContent(array $activity, array $item)
 813         {
 814                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 815                         $item['title'] = strip_tags($activity['name'] ?? '');
 816                         $content = Markdown::toBBCode($activity['content']);
 817                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 818                         $item['title'] = $activity['name'];
 819                         $content = $activity['content'];
 820                 } else {
 821                         // By default assume "text/html"
 822                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 823                         $content = HTML::toBBCode($activity['content'] ?? '');
 824                 }
 825
 826                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 827
 828                 if (!empty($activity['languages'])) {
 829                         $item['language'] = self::processLanguages($activity['languages']);
 830                 }
 831
 832                 if (!empty($activity['emojis'])) {
 833                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 834                 }
 835
 836                 $content = self::addMentionLinks($content, $activity['tags']);
 837
 838                 if (!empty($activity['quote-url'])) {
 839                         $id = Item::fetchByLink($activity['quote-url']);
 840                         if ($id) {
 841                                 $shared_item = Post::selectFirst(['uri-id'], ['id' => $id]);
 842                                 $item['quote-uri-id'] = $shared_item['uri-id'];
 843                         } elseif ($uri_id = ItemURI::getIdByURI($activity['quote-url'], false)) {
 844                                 Logger::info('Quote was not fetched but the uri-id existed', ['guid' => $item['guid'], 'uri-id' => $item['uri-id'], 'quote' => $activity['quote-url'], 'uri-id' => $uri_id]);
 845                                 $item['quote-uri-id'] = $uri_id;
 846                         } else {
 847                                 Logger::info('Quote was not fetched', ['guid' => $item['guid'], 'uri-id' => $item['uri-id'], 'quote' => $activity['quote-url']]);
 848                         }
 849                 }
 850
 851                 if (!empty($activity['source'])) {
 852                         $item['body'] = $activity['source'];
 853                         $item['raw-body'] = $content;
 854
 855                         $quote_uri_id = Item::getQuoteUriId($item['body']);
 856                         if (empty($item['quote-uri-id']) && !empty($quote_uri_id)) {
 857                                 $item['quote-uri-id'] = $quote_uri_id;
 858                         }
 859
 860                         $item['body'] = BBCode::removeSharedData($item['body']);
 861                 } else {
 862                         $parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
 863                         if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == Item::GRAVITY_COMMENT)) {
 864                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 865                                 if (!DBA::isResult($parent)) {
 866                                         Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
 867                                         return false;
 868                                 }
 869                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 870                         }
 871                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 872                         $item['raw-body'] = $item['body'] = $content;
 873                 }
 874
 875                 self::storeFromBody($item);
 876                 self::storeTags($item['uri-id'], $activity['tags']);
 877
 878                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 879
 880                 $item['location'] = $activity['location'];
 881
 882                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 883                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 884                 }
 885
 886                 $item['app'] = $activity['generator'];
 887
 888                 return $item;
 889         }
 890
 891         /**
 892          * Store hashtags and mentions
 893          *
 894          * @param array $item
 895          */
 896         private static function storeFromBody(array $item)
 897         {
 898                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 899                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 900
 901                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 902         }
 903
 904         /**
 905          * Generate a GUID out of an URL of an ActivityPub post.
 906          *
 907          * @param string $url message URL
 908          * @return string with GUID
 909          */
 910         private static function getGUIDByURL(string $url): string
 911         {
 912                 $parsed = parse_url($url);
 913
 914                 $host_hash = hash('crc32', $parsed['host']);
 915
 916                 unset($parsed["scheme"]);
 917                 unset($parsed["host"]);
 918
 919                 $path = implode("/", $parsed);
 920
 921                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 922         }
 923
 924         /**
 925          * Checks if an incoming message is wanted
 926          *
 927          * @param array $activity
 928          * @param array $item
 929          * @return boolean Is the message wanted?
 930          */
 931         private static function isSolicitedMessage(array $activity, array $item): bool
 932         {
 933                 // The checks are split to improve the support when searching why a message was accepted.
 934                 if (count($activity['receiver']) != 1) {
 935                         // The message has more than one receiver, so it is wanted.
 936                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 937                         return true;
 938                 }
 939
 940                 if ($item['private'] == Item::PRIVATE) {
 941                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 942                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 943                         return true;
 944                 }
 945
 946                 if (!empty($activity['from-relay'])) {
 947                         // We check relay posts at another place. When it arrived here, the message is already checked.
 948                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 949                         return true;
 950                 }
 951
 952                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUNCE])) {
 953                         // Manual completions and completions caused by reshares are allowed without any further checks.
 954                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 955                         return true;
 956                 }
 957
 958                 if ($item['gravity'] != Item::GRAVITY_PARENT) {
 959                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 960                         // This can possibly be improved in the future.
 961                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 962                         return true;
 963                 }
 964
 965                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 966                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB, $activity['thread-completion'] ?? 0)) {
 967                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 968                         return true;
 969                 } else {
 970                         return false;
 971                 }
 972         }
 973
 974         /**
 975          * Creates an item post
 976          *
 977          * @param array $activity Activity data
 978          * @param array $item     item array
 979          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 980          * @throws \ImagickException
 981          */
 982         public static function postItem(array $activity, array $item)
 983         {
 984                 if (empty($item)) {
 985                         return;
 986                 }
 987
 988                 $stored = false;
 989                 $success = false;
 990                 ksort($activity['receiver']);
 991
 992                 if (!self::isSolicitedMessage($activity, $item)) {
 993                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
 994                         if (!empty($activity['entry-id'])) {
 995                                 Queue::deleteById($activity['entry-id']);
 996                         }
 997                         return;
 998                 }
 999
1000                 foreach ($activity['receiver'] as $receiver) {
1001                         if ($receiver == -1) {
1002                                 continue;
1003                         }
1004
1005                         if (($receiver != 0) && empty($item['parent-uri-id']) && !empty($item['thr-parent-id'])) {
1006                                 $parent = Post::selectFirst(['parent-uri-id', 'parent-uri'], ['uri-id' => $item['thr-parent-id'], 'uid' => [0, $receiver]]);
1007                                 if (!empty($parent['parent-uri-id'])) {
1008                                         $item['parent-uri-id'] = $parent['parent-uri-id'];
1009                                         $item['parent-uri']    = $parent['parent-uri'];
1010                                 }
1011                         }
1012
1013                         $item['uid'] = $receiver;
1014
1015                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
1016                         switch($type) {
1017                                 case Receiver::TARGET_TO:
1018                                         $item['post-reason'] = Item::PR_TO;
1019                                         break;
1020                                 case Receiver::TARGET_CC:
1021                                         $item['post-reason'] = Item::PR_CC;
1022                                         break;
1023                                 case Receiver::TARGET_BTO:
1024                                         $item['post-reason'] = Item::PR_BTO;
1025                                         break;
1026                                 case Receiver::TARGET_BCC:
1027                                         $item['post-reason'] = Item::PR_BCC;
1028                                         break;
1029                                 case Receiver::TARGET_FOLLOWER:
1030                                         $item['post-reason'] = Item::PR_FOLLOWER;
1031                                         break;
1032                                 case Receiver::TARGET_ANSWER:
1033                                         $item['post-reason'] = Item::PR_COMMENT;
1034                                         break;
1035                                 case Receiver::TARGET_GLOBAL:
1036                                         $item['post-reason'] = Item::PR_GLOBAL;
1037                                         break;
1038                                 default:
1039                                         $item['post-reason'] = Item::PR_NONE;
1040                         }
1041
1042                         $item['post-reason'] = Item::getPostReason($item);
1043
1044                         if (in_array($item['post-reason'], [Item::PR_GLOBAL, Item::PR_NONE])) {
1045                                 if (!empty($activity['from-relay'])) {
1046                                         $item['post-reason'] = Item::PR_RELAY;
1047                                 } elseif (!empty($activity['thread-completion'])) {
1048                                         $item['post-reason'] = Item::PR_FETCHED;
1049                                 } elseif (!empty($activity['push'])) {
1050                                         $item['post-reason'] = Item::PR_PUSHED;
1051                                 }
1052                         } elseif (($item['post-reason'] == Item::PR_FOLLOWER) && !empty($activity['from-relay'])) {
1053                                 // When a post arrives via a relay and we follow the author, we have to override the causer.
1054                                 // Otherwise the system assumes that we follow the relay. (See "addRowInformation")
1055                                 Logger::debug('Relay post for follower', ['receiver' => $receiver, 'guid' => $item['guid'], 'relay' => $activity['from-relay']]);
1056                                 $item['causer-id'] = ($item['gravity'] == Item::GRAVITY_PARENT) ? $item['owner-id'] : $item['author-id'];
1057                         }
1058
1059                         if ($item['isForum'] ?? false) {
1060                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
1061                         } else {
1062                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
1063                         }
1064
1065                         if (($receiver != 0) && empty($item['contact-id'])) {
1066                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
1067                         }
1068
1069                         if (!empty($activity['directmessage'])) {
1070                                 self::postMail($activity, $item);
1071                                 continue;
1072                         }
1073
1074                         if (($receiver != 0) && ($item['gravity'] == Item::GRAVITY_PARENT) && !in_array($item['post-reason'], [Item::PR_FOLLOWER, Item::PR_TAG, item::PR_TO, Item::PR_CC])) {
1075                                 if (!($item['isForum'] ?? false)) {
1076                                         if ($item['post-reason'] == Item::PR_BCC) {
1077                                                 Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id'], 'url' => $item['uri']]);
1078                                                 continue;
1079                                         }
1080
1081                                         if ((DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE)
1082                                                 && in_array($activity['thread-children-type'] ?? '', Receiver::ACTIVITY_TYPES)) {
1083                                                 Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
1084                                                         ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
1085                                                 continue;
1086                                         }
1087                                 }
1088
1089                                 $is_forum = false;
1090                                 $user = User::getById($receiver, ['account-type']);
1091                                 if (!empty($user['account-type'])) {
1092                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
1093                                 }
1094
1095                                 if ((DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE)
1096                                         && ((!$is_forum && !($item['isForum'] ?? false) && ($activity['type'] != 'as:Announce'))
1097                                         || !Contact::isSharingByURL($activity['actor'], $receiver))) {
1098                                         Logger::info('Actor is a non sharer, is no forum or it is no announce', ['uid' => $receiver, 'actor' => $activity['actor'], 'url' => $item['uri'], 'type' => $activity['type']]);
1099                                         continue;
1100                                 }
1101
1102                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
1103                         }
1104
1105                         if (!self::hasParents($item, $receiver)) {
1106                                 continue;
1107                         }
1108
1109                         if (($item['gravity'] != Item::GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
1110                                 $event_id = self::createEvent($activity, $item);
1111
1112                                 $item = Event::getItemArrayForImportedId($event_id, $item);
1113                         }
1114
1115                         $item_id = Item::insert($item);
1116                         if ($item_id) {
1117                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
1118                                 $success = true;
1119                         } else {
1120                                 Logger::notice('Item insertion aborted', ['uri' => $item['uri'], 'uid' => $item['uid']]);
1121                                 if (($item['uid'] == 0) && (count($activity['receiver']) > 1)) {
1122                                         Logger::info('Public item was aborted. We skip for all users.', ['uri' => $item['uri']]);
1123                                         break;
1124                                 }
1125                         }
1126
1127                         if ($item['uid'] == 0) {
1128                                 $stored = $item_id;
1129                         }
1130                 }
1131
1132                 Queue::remove($activity);
1133
1134                 if ($success && Queue::hasChildren($item['uri']) && Post::exists(['uri' => $item['uri']])) {
1135                         Queue::processReplyByUri($item['uri']);
1136                 }
1137
1138                 // Store send a follow request for every reshare - but only when the item had been stored
1139                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == Item::GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
1140                         $author = APContact::getByURL($item['owner-link'], false);
1141                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
1142                         if ($author['type'] != 'Group') {
1143                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
1144                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
1145                         }
1146                 }
1147         }
1148
1149         /**
1150          * Checks if there are parent posts for the given receiver.
1151          * If not, then the system will try to add them.
1152          *
1153          * @param array $item
1154          * @param integer $receiver
1155          * @return boolean
1156          */
1157         private static function hasParents(array $item, int $receiver)
1158         {
1159                 if (($receiver == 0) || ($item['gravity'] == Item::GRAVITY_PARENT)) {
1160                         return true;
1161                 }
1162
1163                 $fields = ['causer-id' => $item['causer-id'] ?? $item['author-id'], 'post-reason' => Item::PR_FETCHED];
1164
1165                 $add_parent = true;
1166
1167                 if ($item['verb'] != Activity::ANNOUNCE) {
1168                         switch (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer')) {
1169                                 case Item::COMPLETION_COMMENT:
1170                                         $add_parent = ($item['gravity'] != Item::GRAVITY_ACTIVITY);
1171                                         break;
1172
1173                                 case Item::COMPLETION_NONE:
1174                                         $add_parent = false;
1175                                         break;
1176                         }
1177                 }
1178
1179                 if ($add_parent) {
1180                         $add_parent = Contact::isSharing($fields['causer-id'], $receiver);
1181                         if (!$add_parent && ($item['author-id'] != $fields['causer-id'])) {
1182                                 $add_parent = Contact::isSharing($item['author-id'], $receiver);
1183                         }
1184                         if (!$add_parent && !in_array($item['owner-id'], [$fields['causer-id'], $item['author-id']])) {
1185                                 $add_parent = Contact::isSharing($item['owner-id'], $receiver);
1186                         }
1187                 }
1188
1189                 $has_parents = false;
1190
1191                 if (!empty($item['parent-uri-id'])) {
1192                         if (Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => $receiver])) {
1193                                 $has_parents = true;
1194                         } elseif ($add_parent && Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => 0])) {
1195                                 $stored = Item::storeForUserByUriId($item['parent-uri-id'], $receiver, $fields);
1196                                 $has_parents = (bool)$stored;
1197                                 if ($stored) {
1198                                         Logger::notice('Inserted missing parent post', ['stored' => $stored, 'uid' => $receiver, 'parent' => $item['parent-uri']]);
1199                                 } else {
1200                                         Logger::notice('Parent could not be added.', ['uid' => $receiver, 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1201                                         return false;
1202                                 }
1203                         } elseif ($add_parent) {
1204                                 Logger::debug('Parent does not exist.', ['uid' => $receiver, 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1205                         } else {
1206                                 Logger::debug('Parent should not be added.', ['uid' => $receiver, 'gravity' => $item['gravity'], 'verb' => $item['verb'], 'guid' => $item['guid'], 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1207                         }
1208                 }
1209
1210                 if (empty($item['parent-uri-id']) || ($item['thr-parent-id'] != $item['parent-uri-id'])) {
1211                         if (Post::exists(['uri-id' => $item['thr-parent-id'], 'uid' => $receiver])) {
1212                                 $has_parents = true;
1213                         } elseif (($has_parents || $add_parent) && Post::exists(['uri-id' => $item['thr-parent-id'], 'uid' => 0])) {
1214                                 $stored = Item::storeForUserByUriId($item['thr-parent-id'], $receiver, $fields);
1215                                 $has_parents = $has_parents || (bool)$stored;
1216                                 if ($stored) {
1217                                         Logger::notice('Inserted missing thread parent post', ['stored' => $stored, 'uid' => $receiver, 'thread-parent' => $item['thr-parent']]);
1218                                 } else {
1219                                         Logger::notice('Thread parent could not be added.', ['uid' => $receiver, 'uri' => $item['uri'], 'thread-parent' => $item['thr-parent']]);
1220                                 }
1221                         } elseif ($add_parent) {
1222                                 Logger::debug('Thread parent does not exist.', ['uid' => $receiver, 'uri' => $item['uri'], 'thread-parent' => $item['thr-parent']]);
1223                         } else {
1224                                 Logger::debug('Thread parent should not be added.', ['uid' => $receiver, 'gravity' => $item['gravity'], 'verb' => $item['verb'], 'guid' => $item['guid'], 'uri' => $item['uri'], 'thread-parent' => $item['thr-parent']]);
1225                         }
1226                 }
1227
1228                 return $has_parents;
1229         }
1230
1231         /**
1232          * Store tags and mentions into the tag table
1233          *
1234          * @param integer $uriid
1235          * @param array $tags
1236          */
1237         private static function storeTags(int $uriid, array $tags = null)
1238         {
1239                 foreach ($tags as $tag) {
1240                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1241                                 continue;
1242                         }
1243
1244                         $hash = substr($tag['name'], 0, 1);
1245
1246                         if ($tag['type'] == 'Mention') {
1247                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
1248                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
1249                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
1250                                         $tag['name'] = substr($tag['name'], 1);
1251                                 }
1252                                 $type = Tag::IMPLICIT_MENTION;
1253
1254                                 if (!empty($tag['href'])) {
1255                                         $apcontact = APContact::getByURL($tag['href']);
1256                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
1257                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
1258                                         }
1259                                 }
1260                         } elseif ($tag['type'] == 'Hashtag') {
1261                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
1262                                         $tag['name'] = substr($tag['name'], 1);
1263                                 }
1264                                 $type = Tag::HASHTAG;
1265                         }
1266
1267                         if (empty($tag['name'])) {
1268                                 continue;
1269                         }
1270
1271                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
1272                 }
1273         }
1274
1275         public static function storeReceivers(int $uriid, array $receivers)
1276         {
1277                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
1278                         if (!empty($receivers[$element])) {
1279                                 foreach ($receivers[$element] as $receiver) {
1280                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
1281                                                 $name = Receiver::PUBLIC_COLLECTION;
1282                                         } elseif ($path = parse_url($receiver, PHP_URL_PATH)) {
1283                                                 $name = trim($path, '/');
1284                                         } elseif ($host = parse_url($receiver, PHP_URL_HOST)) {
1285                                                 $name = $host;
1286                                         } else {
1287                                                 Logger::warning('Unable to coerce name from receiver', ['element' => $element, 'type' => $type, 'receiver' => $receiver]);
1288                                                 $name = '';
1289                                         }
1290
1291                                         $target = Tag::getTargetType($receiver);
1292                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
1293                                         Tag::store($uriid, $type, $name, $receiver, $target);
1294                                 }
1295                         }
1296                 }
1297         }
1298
1299         /**
1300          * Creates an mail post
1301          *
1302          * @param array $activity Activity data
1303          * @param array $item     item array
1304          * @return int|bool New mail table row id or false on error
1305          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1306          */
1307         private static function postMail(array $activity, array $item)
1308         {
1309                 if (($item['gravity'] != Item::GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
1310                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
1311                         return false;
1312                 }
1313
1314                 Logger::info('Direct Message', $item);
1315
1316                 $msg = [];
1317                 $msg['uid'] = $item['uid'];
1318
1319                 $msg['contact-id'] = $item['contact-id'];
1320
1321                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1322                 $msg['from-name'] = $contact['name'];
1323                 $msg['from-url'] = $contact['url'];
1324                 $msg['from-photo'] = $contact['photo'];
1325
1326                 $msg['uri'] = $item['uri'];
1327                 $msg['created'] = $item['created'];
1328
1329                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1330                 if (DBA::isResult($parent)) {
1331                         $msg['parent-uri'] = $parent['parent-uri'];
1332                         $msg['title'] = $parent['title'];
1333                 } else {
1334                         $msg['parent-uri'] = $item['thr-parent'];
1335
1336                         if (!empty($item['title'])) {
1337                                 $msg['title'] = $item['title'];
1338                         } elseif (!empty($item['content-warning'])) {
1339                                 $msg['title'] = $item['content-warning'];
1340                         } else {
1341                                 // Trying to generate a title out of the body
1342                                 $title = $item['body'];
1343
1344                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1345                                         $title = $matches[3];
1346                                 }
1347
1348                                 $title = trim(BBCode::toPlaintext($title));
1349
1350                                 if (strlen($title) > 20) {
1351                                         $title = substr($title, 0, 20) . '...';
1352                                 }
1353
1354                                 $msg['title'] = $title;
1355                         }
1356                 }
1357                 $msg['body'] = $item['body'];
1358
1359                 return Mail::insert($msg);
1360         }
1361
1362         /**
1363          * Fetch featured posts from a contact with the given url
1364          *
1365          * @param string $url
1366          * @return void
1367          */
1368         public static function fetchFeaturedPosts(string $url)
1369         {
1370                 Logger::info('Fetch featured posts', ['contact' => $url]);
1371
1372                 $apcontact = APContact::getByURL($url);
1373                 if (empty($apcontact['featured'])) {
1374                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1375                         return;
1376                 }
1377
1378                 $pcid = Contact::getIdForURL($url, 0, false);
1379                 if (empty($pcid)) {
1380                         Logger::notice('Contact not found', ['contact' => $url]);
1381                         return;
1382                 }
1383
1384                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1385                 if (!empty($posts)) {
1386                         $old_featured = array_column($posts, 'uri-id');
1387                 } else {
1388                         $old_featured = [];
1389                 }
1390
1391                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1392                 if (empty($featured)) {
1393                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1394
1395                         foreach ($old_featured as $uri_id) {
1396                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1397                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1398                         }
1399                         return;
1400                 }
1401
1402                 $new = 0;
1403                 $old = 0;
1404
1405                 foreach ($featured as $post) {
1406                         if (empty($post['id'])) {
1407                                 continue;
1408                         }
1409                         $id = Item::fetchByLink($post['id']);
1410                         if (!empty($id)) {
1411                                 $item = Post::selectFirst(['uri-id', 'featured', 'author-id'], ['id' => $id]);
1412                                 if (!empty($item['uri-id'])) {
1413                                         if (!$item['featured']) {
1414                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED, $item['author-id']);
1415                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1416                                                 $new++;
1417                                         } else {
1418                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1419                                                 $old++;
1420                                         }
1421
1422                                         $index = array_search($item['uri-id'], $old_featured);
1423                                         if (!($index === false)) {
1424                                                 unset($old_featured[$index]);
1425                                         }
1426                                 }
1427                         }
1428                 }
1429
1430                 foreach ($old_featured as $uri_id) {
1431                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1432                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1433                 }
1434
1435                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1436         }
1437
1438         public static function fetchCachedActivity(string $url, int $uid): array
1439         {
1440                 $cachekey = self::CACHEKEY_FETCH_ACTIVITY . $uid . ':' . hash('sha256', $url);
1441                 $object = DI::cache()->get($cachekey);
1442
1443                 if (!is_null($object)) {
1444                         if (!empty($object)) {
1445                                 Logger::debug('Fetch from cache', ['url' => $url, 'uid' => $uid]);
1446                         } else {
1447                                 Logger::debug('Fetch from negative cache', ['url' => $url, 'uid' => $uid]);
1448                         }
1449                         return $object;
1450                 }
1451
1452                 $object = ActivityPub::fetchContent($url, $uid);
1453                 if (empty($object)) {
1454                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
1455                         // We perform negative caching.
1456                         DI::cache()->set($cachekey, [], Duration::FIVE_MINUTES);
1457                         return [];
1458                 }
1459
1460                 if (empty($object['id'])) {
1461                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1462                         return [];
1463                 }
1464                 DI::cache()->set($cachekey, $object, Duration::FIVE_MINUTES);
1465
1466                 Logger::debug('Activity was fetched successfully', ['url' => $url, 'uid' => $uid]);
1467
1468                 return $object;
1469         }
1470
1471         /**
1472          * Fetches missing posts
1473          *
1474          * @param string     $url         message URL
1475          * @param array      $child       activity array with the child of this message
1476          * @param string     $relay_actor Relay actor
1477          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1478          * @param int        $uid         User id that is used to fetch the activity
1479          * @return string fetched message URL
1480          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1481          * @throws \ImagickException
1482          */
1483         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL, int $uid = 0): string
1484         {
1485                 $object = self::fetchCachedActivity($url, $uid);
1486                 if (empty($object)) {
1487                         return '';
1488                 }
1489
1490                 $signer = [];
1491
1492                 if (!empty($object['attributedTo'])) {
1493                         $attributed_to = $object['attributedTo'];
1494                         if (is_array($attributed_to)) {
1495                                 $compacted = JsonLD::compact($object);
1496                                 $attributed_to = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1497                         }
1498                         $signer[] = $attributed_to;
1499                 }
1500
1501                 if (!empty($object['actor'])) {
1502                         $object_actor = $object['actor'];
1503                 } elseif (!empty($attributed_to)) {
1504                         $object_actor = $attributed_to;
1505                 } else {
1506                         // Shouldn't happen
1507                         $object_actor = '';
1508                 }
1509
1510                 $signer[] = $object_actor;
1511
1512                 if (!empty($child['author'])) {
1513                         $actor = $child['author'];
1514                         $signer[] = $actor;
1515                 } else {
1516                         $actor = $object_actor;
1517                 }
1518
1519                 if (!empty($object['published'])) {
1520                         $published = $object['published'];
1521                 } elseif (!empty($child['published'])) {
1522                         $published = $child['published'];
1523                 } else {
1524                         $published = DateTimeFormat::utcNow();
1525                 }
1526
1527                 $activity = [];
1528                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1529                 unset($object['@context']);
1530                 $activity['id'] = $object['id'];
1531                 $activity['to'] = $object['to'] ?? [];
1532                 $activity['cc'] = $object['cc'] ?? [];
1533                 $activity['actor'] = $actor;
1534                 $activity['object'] = $object;
1535                 $activity['published'] = $published;
1536                 $activity['type'] = 'Create';
1537
1538                 $ldactivity = JsonLD::compact($activity);
1539
1540                 $ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 0;
1541
1542                 if ($object_actor != $actor) {
1543                         Contact::updateByUrlIfNeeded($object_actor);
1544                 }
1545
1546                 Contact::updateByUrlIfNeeded($actor);
1547
1548                 if (!empty($child['thread-completion'])) {
1549                         $ldactivity['thread-completion'] = $child['thread-completion'];
1550                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1551                 } else {
1552                         $ldactivity['thread-completion'] = Contact::getIdForURL($relay_actor ?: $actor);
1553                         $ldactivity['completion-mode']   = $completion;
1554                 }
1555
1556                 if ($completion == Receiver::COMPLETION_RELAY) {
1557                         $ldactivity['from-relay'] = $ldactivity['thread-completion'];
1558                         if (!self::acceptIncomingMessage($ldactivity, $object['id'])) {
1559                                 return '';
1560                         }
1561                 }
1562
1563                 if (!empty($child['thread-children-type'])) {
1564                         $ldactivity['thread-children-type'] = $child['thread-children-type'];
1565                 } elseif (!empty($child['type'])) {
1566                         $ldactivity['thread-children-type'] = $child['type'];
1567                 } else {
1568                         $ldactivity['thread-children-type'] = 'as:Create';
1569                 }
1570
1571                 if (($completion == Receiver::COMPLETION_RELAY) && Queue::exists($url, 'as:Create')) {
1572                         Logger::info('Activity has already been queued.', ['url' => $url, 'object' => $activity['id']]);
1573                 } elseif (ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer, '', $completion)) {
1574                         Logger::info('Activity had been fetched and processed.', ['url' => $url, 'entry' => $child['entry-id'] ?? 0, 'completion' => $completion, 'object' => $activity['id']]);
1575                 } else {
1576                         Logger::info('Activity had been fetched and will be processed later.', ['url' => $url, 'entry' => $child['entry-id'] ?? 0, 'completion' => $completion, 'object' => $activity['id']]);
1577                 }
1578
1579                 return $activity['id'];
1580         }
1581
1582         /**
1583          * Test if incoming relay messages should be accepted
1584          *
1585          * @param array $activity activity array
1586          * @param string $id      object ID
1587          * @return boolean true if message is accepted
1588          */
1589         private static function acceptIncomingMessage(array $activity, string $id): bool
1590         {
1591                 if (empty($activity['as:object'])) {
1592                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1593                         return true;
1594                 }
1595
1596                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1597                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1598                 if (Post::exists(['uri-id' => $uriid])) {
1599                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1600                         return true;
1601                 }
1602
1603                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1604                 $authorid = Contact::getIdForURL($attributed_to);
1605
1606                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1607
1608                 $messageTags = [];
1609                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1610                 if (!empty($tags)) {
1611                         foreach ($tags as $tag) {
1612                                 if ($tag['type'] != 'Hashtag') {
1613                                         continue;
1614                                 }
1615                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1616                         }
1617                 }
1618
1619                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB, $activity['thread-completion'] ?? 0);
1620         }
1621
1622         /**
1623          * perform a "follow" request
1624          *
1625          * @param array $activity
1626          * @return void
1627          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1628          * @throws \ImagickException
1629          */
1630         public static function followUser(array $activity)
1631         {
1632                 $uid = User::getIdForURL($activity['object_id']);
1633                 if (empty($uid)) {
1634                         Queue::remove($activity);
1635                         return;
1636                 }
1637
1638                 $owner = User::getOwnerDataById($uid);
1639                 if (empty($owner)) {
1640                         return;
1641                 }
1642
1643                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1644                 if (!empty($cid)) {
1645                         self::switchContact($cid);
1646                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1647                 }
1648
1649                 $item = [
1650                         'author-id' => Contact::getIdForURL($activity['actor']),
1651                         'author-link' => $activity['actor'],
1652                 ];
1653
1654                 // Ensure that the contact has got the right network type
1655                 self::switchContact($item['author-id']);
1656
1657                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1658                 if ($result === true) {
1659                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1660                 }
1661
1662                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1663                 if (empty($cid)) {
1664                         return;
1665                 }
1666
1667                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1668                         self::transmitPendingEvents($cid, $owner['uid']);
1669                 }
1670
1671                 if (empty($contact)) {
1672                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1673                 }
1674                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1675                 Queue::remove($activity);
1676         }
1677
1678         /**
1679          * Transmit pending events to the new follower
1680          *
1681          * @param integer $cid Contact id
1682          * @param integer $uid User id
1683          * @return void
1684          */
1685         private static function transmitPendingEvents(int $cid, int $uid)
1686         {
1687                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1688                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1689
1690                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1691                 while ($event = DBA::fetch($events)) {
1692                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1693                         if (empty($post)) {
1694                                 continue;
1695                         }
1696                         if (DI::config()->get('system', 'bulk_delivery')) {
1697                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1698                                 Worker::add(Worker::PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1699                         } else {
1700                                 Worker::add(Worker::PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1701                         }
1702                 }
1703         }
1704
1705         /**
1706          * Update the given profile
1707          *
1708          * @param array $activity
1709          * @throws \Exception
1710          */
1711         public static function updatePerson(array $activity)
1712         {
1713                 if (empty($activity['object_id'])) {
1714                         return;
1715                 }
1716
1717                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1718                 Contact::updateFromProbeByURL($activity['object_id']);
1719                 Queue::remove($activity);
1720         }
1721
1722         /**
1723          * Delete the given profile
1724          *
1725          * @param array $activity
1726          * @return void
1727          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1728          */
1729         public static function deletePerson(array $activity)
1730         {
1731                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1732                         Logger::info('Empty object id or actor.');
1733                         Queue::remove($activity);
1734                         return;
1735                 }
1736
1737                 if ($activity['object_id'] != $activity['actor']) {
1738                         Logger::info('Object id does not match actor.');
1739                         Queue::remove($activity);
1740                         return;
1741                 }
1742
1743                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1744                 while ($contact = DBA::fetch($contacts)) {
1745                         Contact::remove($contact['id']);
1746                 }
1747                 DBA::close($contacts);
1748
1749                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1750                 Queue::remove($activity);
1751         }
1752
1753         /**
1754          * Add moved contacts as followers for all subscribers of the old contact
1755          *
1756          * @param array $activity
1757          * @return void
1758          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1759          */
1760         public static function movePerson(array $activity)
1761         {
1762                 if (empty($activity['target_id']) || empty($activity['object_id'])) {
1763                         Queue::remove($activity);
1764                         return;
1765                 }
1766
1767                 if ($activity['object_id'] != $activity['actor']) {
1768                         Logger::notice('Object is not the actor', ['activity' => $activity]);
1769                         Queue::remove($activity);
1770                         return;
1771                 }
1772
1773                 $from = Contact::getByURL($activity['object_id'], false, ['uri-id']);
1774                 if (empty($from['uri-id'])) {
1775                         Logger::info('Object not found', ['activity' => $activity]);
1776                         Queue::remove($activity);
1777                         return;
1778                 }
1779
1780                 $contacts = DBA::select('contact', ['uid', 'url'], ["`uri-id` = ? AND `uid` != ? AND `rel` IN (?, ?)", $from['uri-id'], 0, Contact::FRIEND, Contact::SHARING]);
1781                 while ($from_contact = DBA::fetch($contacts)) {
1782                         $result = Contact::createFromProbeForUser($from_contact['uid'], $activity['target_id']);
1783                         Logger::debug('Follower added', ['from' => $from_contact, 'result' => $result]);
1784                 }
1785                 DBA::close($contacts);
1786                 Queue::remove($activity);
1787         }
1788
1789         /**
1790          * Blocks the user by the contact
1791          *
1792          * @param array $activity
1793          * @return void
1794          * @throws \Exception
1795          */
1796         public static function blockAccount(array $activity)
1797         {
1798                 $cid = Contact::getIdForURL($activity['actor']);
1799                 if (empty($cid)) {
1800                         return;
1801                 }
1802
1803                 $uid = User::getIdForURL($activity['object_id']);
1804                 if (empty($uid)) {
1805                         return;
1806                 }
1807
1808                 Contact\User::setIsBlocked($cid, $uid, true);
1809
1810                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1811                 Queue::remove($activity);
1812         }
1813
1814         /**
1815          * Unblocks the user by the contact
1816          *
1817          * @param array $activity
1818          * @return void
1819          * @throws \Exception
1820          */
1821         public static function unblockAccount(array $activity)
1822         {
1823                 $cid = Contact::getIdForURL($activity['actor']);
1824                 if (empty($cid)) {
1825                         return;
1826                 }
1827
1828                 $uid = User::getIdForURL($activity['object_object']);
1829                 if (empty($uid)) {
1830                         return;
1831                 }
1832
1833                 Contact\User::setIsBlocked($cid, $uid, false);
1834
1835                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1836                 Queue::remove($activity);
1837         }
1838
1839         /**
1840          * Report a user
1841          *
1842          * @param array $activity
1843          * @return void
1844          * @throws \Exception
1845          */
1846         public static function ReportAccount(array $activity)
1847         {
1848                 $account_id = Contact::getIdForURL($activity['object_id']);
1849                 if (empty($account_id)) {
1850                         Logger::info('Unknown account', ['activity' => $activity]);
1851                         Queue::remove($activity);
1852                         return;
1853                 }
1854
1855                 $reporter_id = Contact::getIdForURL($activity['actor']);
1856                 if (empty($reporter_id)) {
1857                         Logger::info('Unknown actor', ['activity' => $activity]);
1858                         Queue::remove($activity);
1859                         return;
1860                 }
1861
1862                 $uri_ids = [];
1863                 foreach ($activity['object_ids'] as $status_id) {
1864                         $post = Post::selectFirst(['uri-id'], ['uri' => $status_id]);
1865                         if (!empty($post['uri-id'])) {
1866                                 $uri_ids[] = $post['uri-id'];
1867                         }
1868                 }
1869
1870                 $report = DI::reportFactory()->createFromReportsRequest($reporter_id, $account_id, $activity['content'], null, '', false, $uri_ids);
1871                 DI::report()->save($report);
1872
1873                 Logger::info('Stored report', ['reporter' => $reporter_id, 'account_id' => $account_id, 'comment' => $activity['content'], 'object_ids' => $activity['object_ids']]);
1874         }
1875
1876         /**
1877          * Accept a follow request
1878          *
1879          * @param array $activity
1880          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1881          * @throws \ImagickException
1882          */
1883         public static function acceptFollowUser(array $activity)
1884         {
1885                 if (!empty($activity['object_actor'])) {
1886                         $uid      = User::getIdForURL($activity['object_actor']);
1887                         $check_id = false;
1888                 } elseif (!empty($activity['receiver']) && (count($activity['receiver']) == 1)) {
1889                         $uid      = array_shift($activity['receiver']);
1890                         $check_id = true;
1891                 }
1892
1893                 if (empty($uid)) {
1894                         Logger::notice('User could not be detected', ['activity' => $activity]);
1895                         Queue::remove($activity);
1896                         return;
1897                 }
1898
1899                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1900                 if (empty($cid)) {
1901                         Logger::notice('No contact found', ['actor' => $activity['actor']]);
1902                         Queue::remove($activity);
1903                         return;
1904                 }
1905
1906                 $id = Transmitter::activityIDFromContact($cid);
1907                 if ($id == $activity['object_id']) {
1908                         Logger::info('Successful id check', ['uid' => $uid, 'cid' => $cid]);
1909                 } else {
1910                         Logger::info('Unsuccessful id check', ['uid' => $uid, 'cid' => $cid, 'id' => $id, 'object_id' => $activity['object_id']]);
1911                         if ($check_id) {
1912                                 Queue::remove($activity);
1913                                 return;
1914                         }
1915                 }
1916
1917                 self::switchContact($cid);
1918
1919                 $fields = ['pending' => false];
1920
1921                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1922                 if ($contact['rel'] == Contact::FOLLOWER) {
1923                         $fields['rel'] = Contact::FRIEND;
1924                 }
1925
1926                 $condition = ['id' => $cid];
1927                 Contact::update($fields, $condition);
1928                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1929                 Queue::remove($activity);
1930         }
1931
1932         /**
1933          * Reject a follow request
1934          *
1935          * @param array $activity
1936          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1937          * @throws \ImagickException
1938          */
1939         public static function rejectFollowUser(array $activity)
1940         {
1941                 $uid = User::getIdForURL($activity['object_actor']);
1942                 if (empty($uid)) {
1943                         return;
1944                 }
1945
1946                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1947                 if (empty($cid)) {
1948                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1949                         return;
1950                 }
1951
1952                 self::switchContact($cid);
1953
1954                 $contact = Contact::getById($cid, ['rel']);
1955                 if ($contact['rel'] == Contact::SHARING) {
1956                         Contact::remove($cid);
1957                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1958                 } elseif ($contact['rel'] == Contact::FRIEND) {
1959                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1960                 } else {
1961                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1962                 }
1963                 Queue::remove($activity);
1964         }
1965
1966         /**
1967          * Undo activity like "like" or "dislike"
1968          *
1969          * @param array $activity
1970          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1971          * @throws \ImagickException
1972          */
1973         public static function undoActivity(array $activity)
1974         {
1975                 if (empty($activity['object_id'])) {
1976                         return;
1977                 }
1978
1979                 if (empty($activity['object_actor'])) {
1980                         return;
1981                 }
1982
1983                 $author_id = Contact::getIdForURL($activity['object_actor']);
1984                 if (empty($author_id)) {
1985                         return;
1986                 }
1987
1988                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => Item::GRAVITY_ACTIVITY]);
1989                 Queue::remove($activity);
1990         }
1991
1992         /**
1993          * Activity to remove a follower
1994          *
1995          * @param array $activity
1996          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1997          * @throws \ImagickException
1998          */
1999         public static function undoFollowUser(array $activity)
2000         {
2001                 $uid = User::getIdForURL($activity['object_object']);
2002                 if (empty($uid)) {
2003                         return;
2004                 }
2005
2006                 $owner = User::getOwnerDataById($uid);
2007                 if (empty($owner)) {
2008                         return;
2009                 }
2010
2011                 $cid = Contact::getIdForURL($activity['actor'], $uid);
2012                 if (empty($cid)) {
2013                         Logger::info('No contact found', ['actor' => $activity['actor']]);
2014                         return;
2015                 }
2016
2017                 self::switchContact($cid);
2018
2019                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
2020                 if (!DBA::isResult($contact)) {
2021                         return;
2022                 }
2023
2024                 Contact::removeFollower($contact);
2025                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
2026                 Queue::remove($activity);
2027         }
2028
2029         /**
2030          * Switches a contact to AP if needed
2031          *
2032          * @param integer $cid Contact ID
2033          * @return void
2034          * @throws \Exception
2035          */
2036         private static function switchContact(int $cid)
2037         {
2038                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
2039                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
2040                         return;
2041                 }
2042
2043                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
2044                 Contact::updateFromProbe($cid);
2045         }
2046
2047         /**
2048          * Collects implicit mentions like:
2049          * - the author of the parent item
2050          * - all the mentioned conversants in the parent item
2051          *
2052          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
2053          * @return array
2054          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2055          */
2056         private static function getImplicitMentionList(array $parent): array
2057         {
2058                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
2059
2060                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
2061
2062                 $implicit_mentions = [];
2063                 if (empty($parent_author['url'])) {
2064                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
2065                 } else {
2066                         $implicit_mentions[] = $parent_author['url'];
2067                         $implicit_mentions[] = $parent_author['nurl'];
2068                         $implicit_mentions[] = $parent_author['alias'];
2069                 }
2070
2071                 if (!empty($parent['alias'])) {
2072                         $implicit_mentions[] = $parent['alias'];
2073                 }
2074
2075                 foreach ($parent_terms as $term) {
2076                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
2077                         if (!empty($contact['url'])) {
2078                                 $implicit_mentions[] = $contact['url'];
2079                                 $implicit_mentions[] = $contact['nurl'];
2080                                 $implicit_mentions[] = $contact['alias'];
2081                         }
2082                 }
2083
2084                 return $implicit_mentions;
2085         }
2086
2087         /**
2088          * Strips from the body prepended implicit mentions
2089          *
2090          * @param string $body
2091          * @param array $parent
2092          * @return string
2093          */
2094         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
2095         {
2096                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
2097                         return $body;
2098                 }
2099
2100                 $potential_mentions = self::getImplicitMentionList($parent);
2101
2102                 $kept_mentions = [];
2103
2104                 // Extract one prepended mention at a time from the body
2105                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
2106                         if (!in_array($matches[2], $potential_mentions)) {
2107                                 $kept_mentions[] = $matches[1];
2108                         }
2109
2110                         $body = $matches[3];
2111                 }
2112
2113                 // Re-appending the kept mentions to the body after extraction
2114                 $kept_mentions[] = $body;
2115
2116                 return implode('', $kept_mentions);
2117         }
2118
2119         /**
2120          * Adds links to string mentions
2121          *
2122          * @param string $body
2123          * @param array  $tags
2124          * @return string
2125          */
2126         protected static function addMentionLinks(string $body, array $tags): string
2127         {
2128                 // This prevents links to be added again to Pleroma-style mention links
2129                 $body = self::normalizeMentionLinks($body);
2130
2131                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
2132                         foreach ($tags as $tag) {
2133                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
2134                                         continue;
2135                                 }
2136
2137                                 $hash = substr($tag['name'], 0, 1);
2138                                 $name = substr($tag['name'], 1);
2139                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
2140                                         $hash = '';
2141                                         $name = $tag['name'];
2142                                 }
2143
2144                                 if (Network::isValidHttpUrl($tag['href'])) {
2145                                         $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
2146                                 }
2147                         }
2148
2149                         return $body;
2150                 });
2151
2152                 return $body;
2153         }
2154 }