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                 $item['isGroup'] = false;
 419
 420                 if (!empty($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                         $item['isGroup'] = ($actor['type'] ?? 'Person') == 'Group';
 438                 }
 439
 440                 if (!$item['isGroup'] && !empty($activity['receiver_urls']['as:audience'])) {
 441                         foreach ($activity['receiver_urls']['as:audience'] as $audience) {
 442                                 $actor = APContact::getByURL($audience, false);
 443                                 if (($actor['type'] ?? 'Person') == 'Group') {
 444                                         Logger::debug('Set owner to audience', ['audience' => $audience, 'actor' => $activity['actor'], 'author' => $activity['author']]);
 445                                         $item['isGroup']    = true;
 446                                         $item['owner-link'] = $audience;
 447                                         $item['owner-id']   = Contact::getIdForURL($audience);
 448                                 }
 449                         }
 450                 }
 451
 452                 $item['uri'] = $activity['id'];
 453
 454                 if (empty($activity['published']) || empty($activity['updated'])) {
 455                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 456                 }
 457
 458                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 459                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 460                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 461                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 462
 463                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 464                 if (empty($item['uri-id'])) {
 465                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 466                         return [];
 467                 }
 468
 469                 $item['thr-parent-id'] = ItemURI::getIdByURI($item['thr-parent']);
 470
 471                 $item = self::processContent($activity, $item);
 472                 if (empty($item)) {
 473                         Logger::info('Message was not processed');
 474                         Queue::remove($activity);
 475                         return [];
 476                 }
 477
 478                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 479
 480                 self::storeAttachments($activity, $item);
 481                 self::storeQuestion($activity, $item);
 482
 483                 // We received the post via AP, so we set the protocol of the server to AP
 484                 $contact = Contact::getById($item['author-id'], ['gsid']);
 485                 if (!empty($contact['gsid'])) {
 486                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 487                 }
 488
 489                 if ($item['author-id'] != $item['owner-id']) {
 490                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 491                         if (!empty($contact['gsid'])) {
 492                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 493                         }
 494                 }
 495
 496                 return $item;
 497         }
 498
 499         /**
 500          * Fetch and process parent posts for the given activity
 501          *
 502          * @param array $activity
 503          * @param bool  $in_background
 504          *
 505          * @return string
 506          */
 507         private static function fetchParent(array $activity, bool $in_background = false): string
 508         {
 509                 if (self::isFetched($activity['reply-to-id'])) {
 510                         Logger::info('Id is already fetched', ['id' => $activity['reply-to-id']]);
 511                         return '';
 512                 }
 513
 514                 self::addActivityId($activity['reply-to-id']);
 515
 516                 if (!DI::config()->get('system', 'fetch_by_worker')) {
 517                         $in_background = false;
 518                 }
 519
 520                 $recursion_depth = $activity['recursion-depth'] ?? 0;
 521
 522                 if (!$in_background && ($recursion_depth < DI::config()->get('system', 'max_recursion_depth'))) {
 523                         Logger::info('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 524                         $result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 525                         if (empty($result) && self::isActivityGone($activity['reply-to-id'])) {
 526                                 Logger::notice('The activity is gone, the queue entry will be deleted', ['parent' => $activity['reply-to-id']]);
 527                                 if (!empty($activity['entry-id'])) {
 528                                         Queue::deleteById($activity['entry-id']);
 529                                 }
 530                                 return '';
 531                         } elseif (!empty($result)) {
 532                                 $exists = Post::exists(['uri' => [$result, $activity['reply-to-id']]]);
 533                                 if ($exists) {
 534                                         Logger::info('The activity has been fetched and created.', ['parent' => $result]);
 535                                         return $result;
 536                                 } elseif (DI::config()->get('system', 'fetch_by_worker') || DI::config()->get('system', 'decoupled_receiver')) {
 537                                         Logger::info('The activity has been fetched and will hopefully be created later.', ['parent' => $result]);
 538                                 } else {
 539                                         Logger::notice('The activity exists but has not been created, the queue entry will be deleted.', ['parent' => $result]);
 540                                         if (!empty($activity['entry-id'])) {
 541                                                 Queue::deleteById($activity['entry-id']);
 542                                         }
 543                                 }
 544                                 return '';
 545                         }
 546                         if (empty($result) && !DI::config()->get('system', 'fetch_by_worker')) {
 547                                 return '';
 548                         }
 549                 } elseif (self::isActivityGone($activity['reply-to-id'])) {
 550                         Logger::notice('The activity is gone. We will not spawn a worker. The queue entry will be deleted', ['parent' => $activity['reply-to-id']]);
 551                         if ($in_background) {
 552                                 // fetching in background is done for all activities where we have got the conversation
 553                                 // There we only delete the single activity and not the whole thread since we can store the
 554                                 // other posts in the thread even with missing posts.
 555                                 Queue::remove($activity);
 556                         } elseif (!empty($activity['entry-id'])) {
 557                                 Queue::deleteById($activity['entry-id']);
 558                         }
 559                         return '';
 560                 } elseif ($in_background) {
 561                         Logger::notice('Fetching is done in the background.', ['parent' => $activity['reply-to-id']]);
 562                 } else {
 563                         Logger::notice('Recursion level is too high.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 564                 }
 565
 566                 if (!Fetch::hasWorker($activity['reply-to-id'])) {
 567                         Logger::notice('Fetching is done by worker.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 568                         Fetch::add($activity['reply-to-id']);
 569                         $activity['recursion-depth'] = 0;
 570                         $wid = Worker::add(Worker::PRIORITY_HIGH, 'FetchMissingActivity', $activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 571                         Fetch::setWorkerId($activity['reply-to-id'], $wid);
 572                 } else {
 573                         Logger::debug('Activity will already be fetched via a worker.', ['url' => $activity['reply-to-id']]);
 574                 }
 575
 576                 return '';
 577         }
 578
 579         /**
 580          * Check if a given activity is no longer available
 581          *
 582          * @param string $url
 583          *
 584          * @return boolean
 585          */
 586         public static function isActivityGone(string $url): bool
 587         {
 588                 try {
 589                         $curlResult = HTTPSignature::fetchRaw($url, 0);
 590                 } catch (\Exception $exception) {
 591                         Logger::notice('Error fetching url', ['url' => $url, 'exception' => $exception]);
 592                         return true;
 593                 }
 594
 595                 if (Network::isUrlBlocked($url)) {
 596                         return true;
 597                 }
 598
 599                 // @todo To ensure that the remote system is working correctly, we can check if the "Content-Type" contains JSON
 600                 if (in_array($curlResult->getReturnCode(), [401, 404])) {
 601                         return true;
 602                 }
 603
 604                 if ($curlResult->isSuccess()) {
 605                         $object = json_decode($curlResult->getBody(), true);
 606                         if (!empty($object)) {
 607                                 $activity = JsonLD::compact($object);
 608                                 if (JsonLD::fetchElement($activity, '@type') == 'as:Tombstone') {
 609                                         return true;
 610                                 }
 611                         }
 612                 } elseif ($curlResult->getReturnCode() == 0) {
 613                         $host = parse_url($url, PHP_URL_HOST);
 614                         if (!(filter_var($host, FILTER_VALIDATE_IP) || @dns_get_record($host . '.', DNS_A + DNS_AAAA))) {
 615                                 return true;
 616                         }
 617                 }
 618
 619                 return false;
 620         }
 621         /**
 622          * Delete items
 623          *
 624          * @param array $activity
 625          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 626          * @throws \ImagickException
 627          */
 628         public static function deleteItem(array $activity)
 629         {
 630                 $owner = Contact::getIdForURL($activity['actor']);
 631
 632                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 633                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 634                 Queue::remove($activity);
 635         }
 636
 637         /**
 638          * Prepare the item array for an activity
 639          *
 640          * @param array $activity Activity array
 641          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 642          * @throws \ImagickException
 643          */
 644         public static function addTag(array $activity)
 645         {
 646                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 647                         return;
 648                 }
 649
 650                 foreach ($activity['receiver'] as $receiver) {
 651                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 652                         if (!DBA::isResult($item)) {
 653                                 // We don't fetch missing content for this purpose
 654                                 continue;
 655                         }
 656
 657                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 658                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 659                                 continue;
 660                         }
 661
 662                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 663                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 664                 }
 665         }
 666
 667         /**
 668          * Prepare the item array for an activity
 669          *
 670          * @param array      $activity   Activity array
 671          * @param string     $verb       Activity verb
 672          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 673          * @throws \ImagickException
 674          */
 675         public static function createActivity(array $activity, string $verb)
 676         {
 677                 $activity['reply-to-id'] = $activity['object_id'];
 678                 $item = self::createItem($activity, false);
 679                 if (empty($item)) {
 680                         Logger::debug('Activity was not prepared', ['id' => $activity['object_id']]);
 681                         return;
 682                 }
 683
 684                 $item['verb'] = $verb;
 685                 $item['thr-parent'] = $activity['object_id'];
 686                 $item['gravity'] = Item::GRAVITY_ACTIVITY;
 687                 unset($item['post-type']);
 688                 $item['object-type'] = Activity\ObjectType::NOTE;
 689
 690                 if (!empty($activity['content'])) {
 691                         $item['body'] = HTML::toBBCode($activity['content']);
 692                 }
 693
 694                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 695
 696                 self::postItem($activity, $item);
 697         }
 698
 699         /**
 700          * Fetch the Uri-Id of a post for the "featured" collection
 701          *
 702          * @param array $activity
 703          * @return null|array
 704          */
 705         private static function getUriIdForFeaturedCollection(array $activity)
 706         {
 707                 $actor = APContact::getByURL($activity['actor']);
 708                 if (empty($actor)) {
 709                         return null;
 710                 }
 711
 712                 // Refetch the account when the "featured" collection is missing.
 713                 // This can be removed in a future version (end of 2022 should be good).
 714                 if (empty($actor['featured'])) {
 715                         $actor = APContact::getByURL($activity['actor'], true);
 716                         if (empty($actor)) {
 717                                 return null;
 718                         }
 719                 }
 720
 721                 $parent = Post::selectFirst(['uri-id', 'author-id'], ['uri' => $activity['object_id']]);
 722                 if (empty($parent['uri-id'])) {
 723                         if (self::fetchMissingActivity($activity['object_id'], $activity, '', Receiver::COMPLETION_AUTO)) {
 724                                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 725                         }
 726                 }
 727
 728                 if (!empty($parent['uri-id'])) {
 729                         $parent;
 730                 }
 731
 732                 return null;
 733         }
 734
 735         /**
 736          * Add a post to the "Featured" collection
 737          *
 738          * @param array $activity
 739          */
 740         public static function addToFeaturedCollection(array $activity)
 741         {
 742                 $post = self::getUriIdForFeaturedCollection($activity);
 743                 if (empty($post)) {
 744                         return;
 745                 }
 746
 747                 Logger::debug('Add post to featured collection', ['post' => $post]);
 748
 749                 Post\Collection::add($post['uri-id'], Post\Collection::FEATURED, $post['author-id']);
 750                 Queue::remove($activity);
 751         }
 752
 753         /**
 754          * Remove a post to the "Featured" collection
 755          *
 756          * @param array $activity
 757          */
 758         public static function removeFromFeaturedCollection(array $activity)
 759         {
 760                 $post = self::getUriIdForFeaturedCollection($activity);
 761                 if (empty($post)) {
 762                         return;
 763                 }
 764
 765                 Logger::debug('Remove post from featured collection', ['post' => $post]);
 766
 767                 Post\Collection::remove($post['uri-id'], Post\Collection::FEATURED);
 768                 Queue::remove($activity);
 769         }
 770
 771         /**
 772          * Create an event
 773          *
 774          * @param array $activity Activity array
 775          * @param array $item
 776          *
 777          * @return int event id
 778          * @throws \Exception
 779          */
 780         public static function createEvent(array $activity, array $item): int
 781         {
 782                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 783                 $event['desc']      = HTML::toBBCode($activity['content'] ?? '');
 784                 if (!empty($activity['start-time'])) {
 785                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 786                 }
 787                 if (!empty($activity['end-time'])) {
 788                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 789                 }
 790                 $event['nofinish']  = empty($event['finish']);
 791                 $event['location']  = $activity['location'];
 792                 $event['cid']       = $item['contact-id'];
 793                 $event['uid']       = $item['uid'];
 794                 $event['uri']       = $item['uri'];
 795                 $event['edited']    = $item['edited'];
 796                 $event['private']   = $item['private'];
 797                 $event['guid']      = $item['guid'];
 798                 $event['plink']     = $item['plink'];
 799                 $event['network']   = $item['network'];
 800                 $event['protocol']  = $item['protocol'];
 801                 $event['direction'] = $item['direction'];
 802                 $event['source']    = $item['source'];
 803
 804                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 805                 if (DBA::isResult($ev)) {
 806                         $event['id'] = $ev['id'];
 807                 }
 808
 809                 $event_id = Event::store($event);
 810
 811                 Logger::info('Event was stored', ['id' => $event_id]);
 812
 813                 return $event_id;
 814         }
 815
 816         /**
 817          * Process the content
 818          *
 819          * @param array $activity Activity array
 820          * @param array $item
 821          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 822          * @throws \Exception
 823          */
 824         private static function processContent(array $activity, array $item)
 825         {
 826                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 827                         $item['title'] = strip_tags($activity['name'] ?? '');
 828                         $content = Markdown::toBBCode($activity['content']);
 829                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 830                         $item['title'] = $activity['name'];
 831                         $content = $activity['content'];
 832                 } else {
 833                         // By default assume "text/html"
 834                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 835                         $content = HTML::toBBCode($activity['content'] ?? '');
 836                 }
 837
 838                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 839
 840                 if (!empty($activity['languages'])) {
 841                         $item['language'] = self::processLanguages($activity['languages']);
 842                 }
 843
 844                 if (!empty($activity['emojis'])) {
 845                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 846                 }
 847
 848                 $content = self::addMentionLinks($content, $activity['tags']);
 849
 850                 if (!empty($activity['quote-url'])) {
 851                         $id = Item::fetchByLink($activity['quote-url']);
 852                         if ($id) {
 853                                 $shared_item = Post::selectFirst(['uri-id'], ['id' => $id]);
 854                                 $item['quote-uri-id'] = $shared_item['uri-id'];
 855                         } elseif ($uri_id = ItemURI::getIdByURI($activity['quote-url'], false)) {
 856                                 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]);
 857                                 $item['quote-uri-id'] = $uri_id;
 858                         } else {
 859                                 Logger::info('Quote was not fetched', ['guid' => $item['guid'], 'uri-id' => $item['uri-id'], 'quote' => $activity['quote-url']]);
 860                         }
 861                 }
 862
 863                 if (!empty($activity['source'])) {
 864                         $item['body'] = $activity['source'];
 865                         $item['raw-body'] = $content;
 866
 867                         $quote_uri_id = Item::getQuoteUriId($item['body']);
 868                         if (empty($item['quote-uri-id']) && !empty($quote_uri_id)) {
 869                                 $item['quote-uri-id'] = $quote_uri_id;
 870                         }
 871
 872                         $item['body'] = BBCode::removeSharedData($item['body']);
 873                 } else {
 874                         $parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
 875                         if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == Item::GRAVITY_COMMENT)) {
 876                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 877                                 if (!DBA::isResult($parent)) {
 878                                         Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
 879                                         return false;
 880                                 }
 881                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 882                         }
 883                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 884                         $item['raw-body'] = $item['body'] = $content;
 885                 }
 886
 887                 self::storeFromBody($item);
 888                 self::storeTags($item['uri-id'], $activity['tags']);
 889
 890                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 891
 892                 $item['location'] = $activity['location'];
 893
 894                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 895                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 896                 }
 897
 898                 $item['app'] = $activity['generator'];
 899
 900                 return $item;
 901         }
 902
 903         /**
 904          * Store hashtags and mentions
 905          *
 906          * @param array $item
 907          */
 908         private static function storeFromBody(array $item)
 909         {
 910                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 911                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 912
 913                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 914         }
 915
 916         /**
 917          * Generate a GUID out of an URL of an ActivityPub post.
 918          *
 919          * @param string $url message URL
 920          * @return string with GUID
 921          */
 922         private static function getGUIDByURL(string $url): string
 923         {
 924                 $parsed = parse_url($url);
 925
 926                 $host_hash = hash('crc32', $parsed['host']);
 927
 928                 unset($parsed["scheme"]);
 929                 unset($parsed["host"]);
 930
 931                 $path = implode("/", $parsed);
 932
 933                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 934         }
 935
 936         /**
 937          * Checks if an incoming message is wanted
 938          *
 939          * @param array $activity
 940          * @param array $item
 941          * @return boolean Is the message wanted?
 942          */
 943         private static function isSolicitedMessage(array $activity, array $item): bool
 944         {
 945                 // The checks are split to improve the support when searching why a message was accepted.
 946                 if (count($activity['receiver']) != 1) {
 947                         // The message has more than one receiver, so it is wanted.
 948                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 949                         return true;
 950                 }
 951
 952                 if ($item['private'] == Item::PRIVATE) {
 953                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 954                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 955                         return true;
 956                 }
 957
 958                 if (!empty($activity['from-relay'])) {
 959                         // We check relay posts at another place. When it arrived here, the message is already checked.
 960                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 961                         return true;
 962                 }
 963
 964                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUNCE])) {
 965                         // Manual completions and completions caused by reshares are allowed without any further checks.
 966                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 967                         return true;
 968                 }
 969
 970                 if ($item['gravity'] != Item::GRAVITY_PARENT) {
 971                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 972                         // This can possibly be improved in the future.
 973                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 974                         return true;
 975                 }
 976
 977                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 978                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB, $activity['thread-completion'] ?? 0)) {
 979                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 980                         return true;
 981                 } else {
 982                         return false;
 983                 }
 984         }
 985
 986         /**
 987          * Creates an item post
 988          *
 989          * @param array $activity Activity data
 990          * @param array $item     item array
 991          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 992          * @throws \ImagickException
 993          */
 994         public static function postItem(array $activity, array $item)
 995         {
 996                 if (empty($item)) {
 997                         return;
 998                 }
 999
1000                 $stored = false;
1001                 $success = false;
1002                 ksort($activity['receiver']);
1003
1004                 if (!self::isSolicitedMessage($activity, $item)) {
1005                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
1006                         if (!empty($activity['entry-id'])) {
1007                                 Queue::deleteById($activity['entry-id']);
1008                         }
1009                         return;
1010                 }
1011
1012                 foreach ($activity['receiver'] as $receiver) {
1013                         if ($receiver == -1) {
1014                                 continue;
1015                         }
1016
1017                         if (($receiver != 0) && empty($item['parent-uri-id']) && !empty($item['thr-parent-id'])) {
1018                                 $parent = Post::selectFirst(['parent-uri-id', 'parent-uri'], ['uri-id' => $item['thr-parent-id'], 'uid' => [0, $receiver]]);
1019                                 if (!empty($parent['parent-uri-id'])) {
1020                                         $item['parent-uri-id'] = $parent['parent-uri-id'];
1021                                         $item['parent-uri']    = $parent['parent-uri'];
1022                                 }
1023                         }
1024
1025                         $item['uid'] = $receiver;
1026
1027                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
1028                         switch($type) {
1029                                 case Receiver::TARGET_TO:
1030                                         $item['post-reason'] = Item::PR_TO;
1031                                         break;
1032                                 case Receiver::TARGET_CC:
1033                                         $item['post-reason'] = Item::PR_CC;
1034                                         break;
1035                                 case Receiver::TARGET_BTO:
1036                                         $item['post-reason'] = Item::PR_BTO;
1037                                         break;
1038                                 case Receiver::TARGET_BCC:
1039                                         $item['post-reason'] = Item::PR_BCC;
1040                                         break;
1041                                 case Receiver::TARGET_AUDIENCE:
1042                                         $item['post-reason'] = Item::PR_AUDIENCE;
1043                                         break;
1044                                 case Receiver::TARGET_FOLLOWER:
1045                                         $item['post-reason'] = Item::PR_FOLLOWER;
1046                                         break;
1047                                 case Receiver::TARGET_ANSWER:
1048                                         $item['post-reason'] = Item::PR_COMMENT;
1049                                         break;
1050                                 case Receiver::TARGET_GLOBAL:
1051                                         $item['post-reason'] = Item::PR_GLOBAL;
1052                                         break;
1053                                 default:
1054                                         $item['post-reason'] = Item::PR_NONE;
1055                         }
1056
1057                         $item['post-reason'] = Item::getPostReason($item);
1058
1059                         if (in_array($item['post-reason'], [Item::PR_GLOBAL, Item::PR_NONE])) {
1060                                 if (!empty($activity['from-relay'])) {
1061                                         $item['post-reason'] = Item::PR_RELAY;
1062                                 } elseif (!empty($activity['thread-completion'])) {
1063                                         $item['post-reason'] = Item::PR_FETCHED;
1064                                 } elseif (!empty($activity['push'])) {
1065                                         $item['post-reason'] = Item::PR_PUSHED;
1066                                 }
1067                         } elseif (($item['post-reason'] == Item::PR_FOLLOWER) && !empty($activity['from-relay'])) {
1068                                 // When a post arrives via a relay and we follow the author, we have to override the causer.
1069                                 // Otherwise the system assumes that we follow the relay. (See "addRowInformation")
1070                                 Logger::debug('Relay post for follower', ['receiver' => $receiver, 'guid' => $item['guid'], 'relay' => $activity['from-relay']]);
1071                                 $item['causer-id'] = ($item['gravity'] == Item::GRAVITY_PARENT) ? $item['owner-id'] : $item['author-id'];
1072                         }
1073
1074                         if ($item['isGroup'] ?? false) {
1075                                 $item['contact-id'] = Contact::getIdForURL($item['owner-link'], $receiver);
1076                         } else {
1077                                 $item['contact-id'] = Contact::getIdForURL($item['author-link'], $receiver);
1078                         }
1079
1080                         if (($receiver != 0) && empty($item['contact-id'])) {
1081                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
1082                         }
1083
1084                         if (!empty($activity['directmessage'])) {
1085                                 self::postMail($activity, $item);
1086                                 continue;
1087                         }
1088
1089                         if (($receiver != 0) && ($item['gravity'] == Item::GRAVITY_PARENT) && !in_array($item['post-reason'], [Item::PR_FOLLOWER, Item::PR_TAG, item::PR_TO, Item::PR_CC, Item::PR_AUDIENCE])) {
1090                                 if (!($item['isGroup'] ?? false)) {
1091                                         if ($item['post-reason'] == Item::PR_BCC) {
1092                                                 Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id'], 'url' => $item['uri']]);
1093                                                 continue;
1094                                         }
1095
1096                                         if ((DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE)
1097                                                 && in_array($activity['thread-children-type'] ?? '', Receiver::ACTIVITY_TYPES)) {
1098                                                 Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
1099                                                         ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
1100                                                 continue;
1101                                         }
1102                                 }
1103
1104                                 $isGroup = false;
1105                                 $user = User::getById($receiver, ['account-type']);
1106                                 if (!empty($user['account-type'])) {
1107                                         $isGroup = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
1108                                 }
1109
1110                                 if ((DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE)
1111                                         && ((!$isGroup && !($item['isGroup'] ?? false) && ($activity['type'] != 'as:Announce'))
1112                                         || !Contact::isSharingByURL($activity['actor'], $receiver))) {
1113                                         Logger::info('Actor is a non sharer, is no group or it is no announce', ['uid' => $receiver, 'actor' => $activity['actor'], 'url' => $item['uri'], 'type' => $activity['type']]);
1114                                         continue;
1115                                 }
1116
1117                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
1118                         }
1119
1120                         if (!self::hasParents($item, $receiver)) {
1121                                 continue;
1122                         }
1123
1124                         if (($item['gravity'] != Item::GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
1125                                 $event_id = self::createEvent($activity, $item);
1126
1127                                 $item = Event::getItemArrayForImportedId($event_id, $item);
1128                         }
1129
1130                         $item_id = Item::insert($item);
1131                         if ($item_id) {
1132                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
1133                                 $success = true;
1134                         } else {
1135                                 Logger::notice('Item insertion aborted', ['uri' => $item['uri'], 'uid' => $item['uid']]);
1136                                 if (($item['uid'] == 0) && (count($activity['receiver']) > 1)) {
1137                                         Logger::info('Public item was aborted. We skip for all users.', ['uri' => $item['uri']]);
1138                                         break;
1139                                 }
1140                         }
1141
1142                         if ($item['uid'] == 0) {
1143                                 $stored = $item_id;
1144                         }
1145                 }
1146
1147                 Queue::remove($activity);
1148
1149                 if ($success && Queue::hasChildren($item['uri']) && Post::exists(['uri' => $item['uri']])) {
1150                         Queue::processReplyByUri($item['uri']);
1151                 }
1152
1153                 // Store send a follow request for every reshare - but only when the item had been stored
1154                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == Item::GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
1155                         $author = APContact::getByURL($item['owner-link'], false);
1156                         // We send automatic follow requests for reshared messages. (We don't need though for group posts)
1157                         if ($author['type'] != 'Group') {
1158                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
1159                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
1160                         }
1161                 }
1162         }
1163
1164         /**
1165          * Checks if there are parent posts for the given receiver.
1166          * If not, then the system will try to add them.
1167          *
1168          * @param array $item
1169          * @param integer $receiver
1170          * @return boolean
1171          */
1172         private static function hasParents(array $item, int $receiver)
1173         {
1174                 if (($receiver == 0) || ($item['gravity'] == Item::GRAVITY_PARENT)) {
1175                         return true;
1176                 }
1177
1178                 $fields = ['causer-id' => $item['causer-id'] ?? $item['author-id'], 'post-reason' => Item::PR_FETCHED];
1179
1180                 $add_parent = true;
1181
1182                 if ($item['verb'] != Activity::ANNOUNCE) {
1183                         switch (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer')) {
1184                                 case Item::COMPLETION_COMMENT:
1185                                         $add_parent = ($item['gravity'] != Item::GRAVITY_ACTIVITY);
1186                                         break;
1187
1188                                 case Item::COMPLETION_NONE:
1189                                         $add_parent = false;
1190                                         break;
1191                         }
1192                 }
1193
1194                 if ($add_parent) {
1195                         $add_parent = Contact::isSharing($fields['causer-id'], $receiver);
1196                         if (!$add_parent && ($item['author-id'] != $fields['causer-id'])) {
1197                                 $add_parent = Contact::isSharing($item['author-id'], $receiver);
1198                         }
1199                         if (!$add_parent && !in_array($item['owner-id'], [$fields['causer-id'], $item['author-id']])) {
1200                                 $add_parent = Contact::isSharing($item['owner-id'], $receiver);
1201                         }
1202                 }
1203
1204                 $has_parents = false;
1205
1206                 if (!empty($item['parent-uri-id'])) {
1207                         if (Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => $receiver])) {
1208                                 $has_parents = true;
1209                         } elseif ($add_parent && Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => 0])) {
1210                                 $stored = Item::storeForUserByUriId($item['parent-uri-id'], $receiver, $fields);
1211                                 $has_parents = (bool)$stored;
1212                                 if ($stored) {
1213                                         Logger::notice('Inserted missing parent post', ['stored' => $stored, 'uid' => $receiver, 'parent' => $item['parent-uri']]);
1214                                 } else {
1215                                         Logger::notice('Parent could not be added.', ['uid' => $receiver, 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1216                                         return false;
1217                                 }
1218                         } elseif ($add_parent) {
1219                                 Logger::debug('Parent does not exist.', ['uid' => $receiver, 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1220                         } else {
1221                                 Logger::debug('Parent should not be added.', ['uid' => $receiver, 'gravity' => $item['gravity'], 'verb' => $item['verb'], 'guid' => $item['guid'], 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1222                         }
1223                 }
1224
1225                 if (empty($item['parent-uri-id']) || ($item['thr-parent-id'] != $item['parent-uri-id'])) {
1226                         if (Post::exists(['uri-id' => $item['thr-parent-id'], 'uid' => $receiver])) {
1227                                 $has_parents = true;
1228                         } elseif (($has_parents || $add_parent) && Post::exists(['uri-id' => $item['thr-parent-id'], 'uid' => 0])) {
1229                                 $stored = Item::storeForUserByUriId($item['thr-parent-id'], $receiver, $fields);
1230                                 $has_parents = $has_parents || (bool)$stored;
1231                                 if ($stored) {
1232                                         Logger::notice('Inserted missing thread parent post', ['stored' => $stored, 'uid' => $receiver, 'thread-parent' => $item['thr-parent']]);
1233                                 } else {
1234                                         Logger::notice('Thread parent could not be added.', ['uid' => $receiver, 'uri' => $item['uri'], 'thread-parent' => $item['thr-parent']]);
1235                                 }
1236                         } elseif ($add_parent) {
1237                                 Logger::debug('Thread parent does not exist.', ['uid' => $receiver, 'uri' => $item['uri'], 'thread-parent' => $item['thr-parent']]);
1238                         } else {
1239                                 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']]);
1240                         }
1241                 }
1242
1243                 return $has_parents;
1244         }
1245
1246         /**
1247          * Store tags and mentions into the tag table
1248          *
1249          * @param integer $uriid
1250          * @param array $tags
1251          */
1252         private static function storeTags(int $uriid, array $tags = null)
1253         {
1254                 foreach ($tags as $tag) {
1255                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1256                                 continue;
1257                         }
1258
1259                         $hash = substr($tag['name'], 0, 1);
1260
1261                         if ($tag['type'] == 'Mention') {
1262                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
1263                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
1264                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
1265                                         $tag['name'] = substr($tag['name'], 1);
1266                                 }
1267                                 $type = Tag::IMPLICIT_MENTION;
1268
1269                                 if (!empty($tag['href'])) {
1270                                         $apcontact = APContact::getByURL($tag['href']);
1271                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
1272                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
1273                                         }
1274                                 }
1275                         } elseif ($tag['type'] == 'Hashtag') {
1276                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
1277                                         $tag['name'] = substr($tag['name'], 1);
1278                                 }
1279                                 $type = Tag::HASHTAG;
1280                         }
1281
1282                         if (empty($tag['name'])) {
1283                                 continue;
1284                         }
1285
1286                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
1287                 }
1288         }
1289
1290         public static function storeReceivers(int $uriid, array $receivers)
1291         {
1292                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC, 'as:audience' => Tag::AUDIENCE, 'as:attributedTo' => Tag::ATTRIBUTED] as $element => $type) {
1293                         if (!empty($receivers[$element])) {
1294                                 foreach ($receivers[$element] as $receiver) {
1295                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
1296                                                 $name = Receiver::PUBLIC_COLLECTION;
1297                                         } elseif ($path = parse_url($receiver, PHP_URL_PATH)) {
1298                                                 $name = trim($path, '/');
1299                                         } elseif ($host = parse_url($receiver, PHP_URL_HOST)) {
1300                                                 $name = $host;
1301                                         } else {
1302                                                 Logger::warning('Unable to coerce name from receiver', ['element' => $element, 'type' => $type, 'receiver' => $receiver]);
1303                                                 $name = '';
1304                                         }
1305
1306                                         $target = Tag::getTargetType($receiver);
1307                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
1308                                         Tag::store($uriid, $type, $name, $receiver, $target);
1309                                 }
1310                         }
1311                 }
1312         }
1313
1314         /**
1315          * Creates an mail post
1316          *
1317          * @param array $activity Activity data
1318          * @param array $item     item array
1319          * @return int|bool New mail table row id or false on error
1320          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1321          */
1322         private static function postMail(array $activity, array $item)
1323         {
1324                 if (($item['gravity'] != Item::GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
1325                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
1326                         return false;
1327                 }
1328
1329                 Logger::info('Direct Message', $item);
1330
1331                 $msg = [];
1332                 $msg['uid'] = $item['uid'];
1333
1334                 $msg['contact-id'] = $item['contact-id'];
1335
1336                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1337                 $msg['from-name'] = $contact['name'];
1338                 $msg['from-url'] = $contact['url'];
1339                 $msg['from-photo'] = $contact['photo'];
1340
1341                 $msg['uri'] = $item['uri'];
1342                 $msg['created'] = $item['created'];
1343
1344                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1345                 if (DBA::isResult($parent)) {
1346                         $msg['parent-uri'] = $parent['parent-uri'];
1347                         $msg['title'] = $parent['title'];
1348                 } else {
1349                         $msg['parent-uri'] = $item['thr-parent'];
1350
1351                         if (!empty($item['title'])) {
1352                                 $msg['title'] = $item['title'];
1353                         } elseif (!empty($item['content-warning'])) {
1354                                 $msg['title'] = $item['content-warning'];
1355                         } else {
1356                                 // Trying to generate a title out of the body
1357                                 $title = $item['body'];
1358
1359                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1360                                         $title = $matches[3];
1361                                 }
1362
1363                                 $title = trim(BBCode::toPlaintext($title));
1364
1365                                 if (strlen($title) > 20) {
1366                                         $title = substr($title, 0, 20) . '...';
1367                                 }
1368
1369                                 $msg['title'] = $title;
1370                         }
1371                 }
1372                 $msg['body'] = $item['body'];
1373
1374                 return Mail::insert($msg);
1375         }
1376
1377         /**
1378          * Fetch featured posts from a contact with the given url
1379          *
1380          * @param string $url
1381          * @return void
1382          */
1383         public static function fetchFeaturedPosts(string $url)
1384         {
1385                 Logger::info('Fetch featured posts', ['contact' => $url]);
1386
1387                 $apcontact = APContact::getByURL($url);
1388                 if (empty($apcontact['featured'])) {
1389                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1390                         return;
1391                 }
1392
1393                 $pcid = Contact::getIdForURL($url, 0, false);
1394                 if (empty($pcid)) {
1395                         Logger::notice('Contact not found', ['contact' => $url]);
1396                         return;
1397                 }
1398
1399                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1400                 if (!empty($posts)) {
1401                         $old_featured = array_column($posts, 'uri-id');
1402                 } else {
1403                         $old_featured = [];
1404                 }
1405
1406                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1407                 if (empty($featured)) {
1408                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1409
1410                         foreach ($old_featured as $uri_id) {
1411                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1412                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1413                         }
1414                         return;
1415                 }
1416
1417                 $new = 0;
1418                 $old = 0;
1419
1420                 foreach ($featured as $post) {
1421                         if (empty($post['id'])) {
1422                                 continue;
1423                         }
1424                         $id = Item::fetchByLink($post['id']);
1425                         if (!empty($id)) {
1426                                 $item = Post::selectFirst(['uri-id', 'featured', 'author-id'], ['id' => $id]);
1427                                 if (!empty($item['uri-id'])) {
1428                                         if (!$item['featured']) {
1429                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED, $item['author-id']);
1430                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1431                                                 $new++;
1432                                         } else {
1433                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1434                                                 $old++;
1435                                         }
1436
1437                                         $index = array_search($item['uri-id'], $old_featured);
1438                                         if (!($index === false)) {
1439                                                 unset($old_featured[$index]);
1440                                         }
1441                                 }
1442                         }
1443                 }
1444
1445                 foreach ($old_featured as $uri_id) {
1446                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1447                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1448                 }
1449
1450                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1451         }
1452
1453         public static function fetchCachedActivity(string $url, int $uid): array
1454         {
1455                 $cachekey = self::CACHEKEY_FETCH_ACTIVITY . $uid . ':' . hash('sha256', $url);
1456                 $object = DI::cache()->get($cachekey);
1457
1458                 if (!is_null($object)) {
1459                         if (!empty($object)) {
1460                                 Logger::debug('Fetch from cache', ['url' => $url, 'uid' => $uid]);
1461                         } else {
1462                                 Logger::debug('Fetch from negative cache', ['url' => $url, 'uid' => $uid]);
1463                         }
1464                         return $object;
1465                 }
1466
1467                 $object = ActivityPub::fetchContent($url, $uid);
1468                 if (empty($object)) {
1469                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
1470                         // We perform negative caching.
1471                         DI::cache()->set($cachekey, [], Duration::FIVE_MINUTES);
1472                         return [];
1473                 }
1474
1475                 if (empty($object['id'])) {
1476                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1477                         return [];
1478                 }
1479                 DI::cache()->set($cachekey, $object, Duration::FIVE_MINUTES);
1480
1481                 Logger::debug('Activity was fetched successfully', ['url' => $url, 'uid' => $uid]);
1482
1483                 return $object;
1484         }
1485
1486         /**
1487          * Fetches missing posts
1488          *
1489          * @param string     $url         message URL
1490          * @param array      $child       activity array with the child of this message
1491          * @param string     $relay_actor Relay actor
1492          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1493          * @param int        $uid         User id that is used to fetch the activity
1494          * @return string fetched message URL
1495          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1496          * @throws \ImagickException
1497          */
1498         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL, int $uid = 0): string
1499         {
1500                 $object = self::fetchCachedActivity($url, $uid);
1501                 if (empty($object)) {
1502                         return '';
1503                 }
1504
1505                 $signer = [];
1506
1507                 if (!empty($object['attributedTo'])) {
1508                         $attributed_to = $object['attributedTo'];
1509                         if (is_array($attributed_to)) {
1510                                 $compacted = JsonLD::compact($object);
1511                                 $attributed_to = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1512                         }
1513                         $signer[] = $attributed_to;
1514                 }
1515
1516                 if (!empty($object['actor'])) {
1517                         $object_actor = $object['actor'];
1518                 } elseif (!empty($attributed_to)) {
1519                         $object_actor = $attributed_to;
1520                 } else {
1521                         // Shouldn't happen
1522                         $object_actor = '';
1523                 }
1524
1525                 $signer[] = $object_actor;
1526
1527                 if (!empty($child['author'])) {
1528                         $actor = $child['author'];
1529                         $signer[] = $actor;
1530                 } else {
1531                         $actor = $object_actor;
1532                 }
1533
1534                 if (!empty($object['published'])) {
1535                         $published = $object['published'];
1536                 } elseif (!empty($child['published'])) {
1537                         $published = $child['published'];
1538                 } else {
1539                         $published = DateTimeFormat::utcNow();
1540                 }
1541
1542                 $activity = [];
1543                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1544                 unset($object['@context']);
1545                 $activity['id'] = $object['id'];
1546                 $activity['to'] = $object['to'] ?? [];
1547                 $activity['cc'] = $object['cc'] ?? [];
1548                 $activity['audience'] = $object['audience'] ?? [];
1549                 $activity['actor'] = $actor;
1550                 $activity['object'] = $object;
1551                 $activity['published'] = $published;
1552                 $activity['type'] = 'Create';
1553
1554                 $ldactivity = JsonLD::compact($activity);
1555
1556                 $ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 0;
1557
1558                 if ($object_actor != $actor) {
1559                         Contact::updateByUrlIfNeeded($object_actor);
1560                 }
1561
1562                 Contact::updateByUrlIfNeeded($actor);
1563
1564                 if (!empty($child['thread-completion'])) {
1565                         $ldactivity['thread-completion'] = $child['thread-completion'];
1566                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1567                 } else {
1568                         $ldactivity['thread-completion'] = Contact::getIdForURL($relay_actor ?: $actor);
1569                         $ldactivity['completion-mode']   = $completion;
1570                 }
1571
1572                 if ($completion == Receiver::COMPLETION_RELAY) {
1573                         $ldactivity['from-relay'] = $ldactivity['thread-completion'];
1574                         if (!self::acceptIncomingMessage($ldactivity, $object['id'])) {
1575                                 return '';
1576                         }
1577                 }
1578
1579                 if (!empty($child['thread-children-type'])) {
1580                         $ldactivity['thread-children-type'] = $child['thread-children-type'];
1581                 } elseif (!empty($child['type'])) {
1582                         $ldactivity['thread-children-type'] = $child['type'];
1583                 } else {
1584                         $ldactivity['thread-children-type'] = 'as:Create';
1585                 }
1586
1587                 if (($completion == Receiver::COMPLETION_RELAY) && Queue::exists($url, 'as:Create')) {
1588                         Logger::info('Activity has already been queued.', ['url' => $url, 'object' => $activity['id']]);
1589                 } elseif (ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer, '', $completion)) {
1590                         Logger::info('Activity had been fetched and processed.', ['url' => $url, 'entry' => $child['entry-id'] ?? 0, 'completion' => $completion, 'object' => $activity['id']]);
1591                 } else {
1592                         Logger::info('Activity had been fetched and will be processed later.', ['url' => $url, 'entry' => $child['entry-id'] ?? 0, 'completion' => $completion, 'object' => $activity['id']]);
1593                 }
1594
1595                 return $activity['id'];
1596         }
1597
1598         /**
1599          * Test if incoming relay messages should be accepted
1600          *
1601          * @param array $activity activity array
1602          * @param string $id      object ID
1603          * @return boolean true if message is accepted
1604          */
1605         private static function acceptIncomingMessage(array $activity, string $id): bool
1606         {
1607                 if (empty($activity['as:object'])) {
1608                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1609                         return true;
1610                 }
1611
1612                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1613                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1614                 if (Post::exists(['uri-id' => $uriid])) {
1615                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1616                         return true;
1617                 }
1618
1619                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1620                 $authorid = Contact::getIdForURL($attributed_to);
1621
1622                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1623
1624                 $messageTags = [];
1625                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1626                 if (!empty($tags)) {
1627                         foreach ($tags as $tag) {
1628                                 if ($tag['type'] != 'Hashtag') {
1629                                         continue;
1630                                 }
1631                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1632                         }
1633                 }
1634
1635                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB, $activity['thread-completion'] ?? 0);
1636         }
1637
1638         /**
1639          * perform a "follow" request
1640          *
1641          * @param array $activity
1642          * @return void
1643          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1644          * @throws \ImagickException
1645          */
1646         public static function followUser(array $activity)
1647         {
1648                 $uid = User::getIdForURL($activity['object_id']);
1649                 if (empty($uid)) {
1650                         Queue::remove($activity);
1651                         return;
1652                 }
1653
1654                 $owner = User::getOwnerDataById($uid);
1655                 if (empty($owner)) {
1656                         return;
1657                 }
1658
1659                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1660                 if (!empty($cid)) {
1661                         self::switchContact($cid);
1662                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1663                 }
1664
1665                 $item = [
1666                         'author-id' => Contact::getIdForURL($activity['actor']),
1667                         'author-link' => $activity['actor'],
1668                 ];
1669
1670                 // Ensure that the contact has got the right network type
1671                 self::switchContact($item['author-id']);
1672
1673                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1674                 if ($result === true) {
1675                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1676                 }
1677
1678                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1679                 if (empty($cid)) {
1680                         return;
1681                 }
1682
1683                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1684                         self::transmitPendingEvents($cid, $owner['uid']);
1685                 }
1686
1687                 if (empty($contact)) {
1688                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1689                 }
1690                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1691                 Queue::remove($activity);
1692         }
1693
1694         /**
1695          * Transmit pending events to the new follower
1696          *
1697          * @param integer $cid Contact id
1698          * @param integer $uid User id
1699          * @return void
1700          */
1701         private static function transmitPendingEvents(int $cid, int $uid)
1702         {
1703                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1704                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1705
1706                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1707                 while ($event = DBA::fetch($events)) {
1708                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1709                         if (empty($post)) {
1710                                 continue;
1711                         }
1712                         if (DI::config()->get('system', 'bulk_delivery')) {
1713                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1714                                 Worker::add(Worker::PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1715                         } else {
1716                                 Worker::add(Worker::PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1717                         }
1718                 }
1719         }
1720
1721         /**
1722          * Update the given profile
1723          *
1724          * @param array $activity
1725          * @throws \Exception
1726          */
1727         public static function updatePerson(array $activity)
1728         {
1729                 if (empty($activity['object_id'])) {
1730                         return;
1731                 }
1732
1733                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1734                 Contact::updateFromProbeByURL($activity['object_id']);
1735                 Queue::remove($activity);
1736         }
1737
1738         /**
1739          * Delete the given profile
1740          *
1741          * @param array $activity
1742          * @return void
1743          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1744          */
1745         public static function deletePerson(array $activity)
1746         {
1747                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1748                         Logger::info('Empty object id or actor.');
1749                         Queue::remove($activity);
1750                         return;
1751                 }
1752
1753                 if ($activity['object_id'] != $activity['actor']) {
1754                         Logger::info('Object id does not match actor.');
1755                         Queue::remove($activity);
1756                         return;
1757                 }
1758
1759                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1760                 while ($contact = DBA::fetch($contacts)) {
1761                         Contact::remove($contact['id']);
1762                 }
1763                 DBA::close($contacts);
1764
1765                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1766                 Queue::remove($activity);
1767         }
1768
1769         /**
1770          * Add moved contacts as followers for all subscribers of the old contact
1771          *
1772          * @param array $activity
1773          * @return void
1774          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1775          */
1776         public static function movePerson(array $activity)
1777         {
1778                 if (empty($activity['target_id']) || empty($activity['object_id'])) {
1779                         Queue::remove($activity);
1780                         return;
1781                 }
1782
1783                 if ($activity['object_id'] != $activity['actor']) {
1784                         Logger::notice('Object is not the actor', ['activity' => $activity]);
1785                         Queue::remove($activity);
1786                         return;
1787                 }
1788
1789                 $from = Contact::getByURL($activity['object_id'], false, ['uri-id']);
1790                 if (empty($from['uri-id'])) {
1791                         Logger::info('Object not found', ['activity' => $activity]);
1792                         Queue::remove($activity);
1793                         return;
1794                 }
1795
1796                 $contacts = DBA::select('contact', ['uid', 'url'], ["`uri-id` = ? AND `uid` != ? AND `rel` IN (?, ?)", $from['uri-id'], 0, Contact::FRIEND, Contact::SHARING]);
1797                 while ($from_contact = DBA::fetch($contacts)) {
1798                         $result = Contact::createFromProbeForUser($from_contact['uid'], $activity['target_id']);
1799                         Logger::debug('Follower added', ['from' => $from_contact, 'result' => $result]);
1800                 }
1801                 DBA::close($contacts);
1802                 Queue::remove($activity);
1803         }
1804
1805         /**
1806          * Blocks the user by the contact
1807          *
1808          * @param array $activity
1809          * @return void
1810          * @throws \Exception
1811          */
1812         public static function blockAccount(array $activity)
1813         {
1814                 $cid = Contact::getIdForURL($activity['actor']);
1815                 if (empty($cid)) {
1816                         return;
1817                 }
1818
1819                 $uid = User::getIdForURL($activity['object_id']);
1820                 if (empty($uid)) {
1821                         return;
1822                 }
1823
1824                 Contact\User::setIsBlocked($cid, $uid, true);
1825
1826                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1827                 Queue::remove($activity);
1828         }
1829
1830         /**
1831          * Unblocks the user by the contact
1832          *
1833          * @param array $activity
1834          * @return void
1835          * @throws \Exception
1836          */
1837         public static function unblockAccount(array $activity)
1838         {
1839                 $cid = Contact::getIdForURL($activity['actor']);
1840                 if (empty($cid)) {
1841                         return;
1842                 }
1843
1844                 $uid = User::getIdForURL($activity['object_object']);
1845                 if (empty($uid)) {
1846                         return;
1847                 }
1848
1849                 Contact\User::setIsBlocked($cid, $uid, false);
1850
1851                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1852                 Queue::remove($activity);
1853         }
1854
1855         /**
1856          * Report a user
1857          *
1858          * @param array $activity
1859          * @return void
1860          * @throws \Exception
1861          */
1862         public static function ReportAccount(array $activity)
1863         {
1864                 $account_id = Contact::getIdForURL($activity['object_id']);
1865                 if (empty($account_id)) {
1866                         Logger::info('Unknown account', ['activity' => $activity]);
1867                         Queue::remove($activity);
1868                         return;
1869                 }
1870
1871                 $reporter_id = Contact::getIdForURL($activity['actor']);
1872                 if (empty($reporter_id)) {
1873                         Logger::info('Unknown actor', ['activity' => $activity]);
1874                         Queue::remove($activity);
1875                         return;
1876                 }
1877
1878                 $uri_ids = [];
1879                 foreach ($activity['object_ids'] as $status_id) {
1880                         $post = Post::selectFirst(['uri-id'], ['uri' => $status_id]);
1881                         if (!empty($post['uri-id'])) {
1882                                 $uri_ids[] = $post['uri-id'];
1883                         }
1884                 }
1885
1886                 $report = DI::reportFactory()->createFromReportsRequest($reporter_id, $account_id, $activity['content'], null, '', false, $uri_ids);
1887                 DI::report()->save($report);
1888
1889                 Logger::info('Stored report', ['reporter' => $reporter_id, 'account_id' => $account_id, 'comment' => $activity['content'], 'object_ids' => $activity['object_ids']]);
1890         }
1891
1892         /**
1893          * Accept a follow request
1894          *
1895          * @param array $activity
1896          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1897          * @throws \ImagickException
1898          */
1899         public static function acceptFollowUser(array $activity)
1900         {
1901                 if (!empty($activity['object_actor'])) {
1902                         $uid      = User::getIdForURL($activity['object_actor']);
1903                         $check_id = false;
1904                 } elseif (!empty($activity['receiver']) && (count($activity['receiver']) == 1)) {
1905                         $uid      = array_shift($activity['receiver']);
1906                         $check_id = true;
1907                 }
1908
1909                 if (empty($uid)) {
1910                         Logger::notice('User could not be detected', ['activity' => $activity]);
1911                         Queue::remove($activity);
1912                         return;
1913                 }
1914
1915                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1916                 if (empty($cid)) {
1917                         Logger::notice('No contact found', ['actor' => $activity['actor']]);
1918                         Queue::remove($activity);
1919                         return;
1920                 }
1921
1922                 $id = Transmitter::activityIDFromContact($cid);
1923                 if ($id == $activity['object_id']) {
1924                         Logger::info('Successful id check', ['uid' => $uid, 'cid' => $cid]);
1925                 } else {
1926                         Logger::info('Unsuccessful id check', ['uid' => $uid, 'cid' => $cid, 'id' => $id, 'object_id' => $activity['object_id']]);
1927                         if ($check_id) {
1928                                 Queue::remove($activity);
1929                                 return;
1930                         }
1931                 }
1932
1933                 self::switchContact($cid);
1934
1935                 $fields = ['pending' => false];
1936
1937                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1938                 if ($contact['rel'] == Contact::FOLLOWER) {
1939                         $fields['rel'] = Contact::FRIEND;
1940                 }
1941
1942                 $condition = ['id' => $cid];
1943                 Contact::update($fields, $condition);
1944                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1945                 Queue::remove($activity);
1946         }
1947
1948         /**
1949          * Reject a follow request
1950          *
1951          * @param array $activity
1952          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1953          * @throws \ImagickException
1954          */
1955         public static function rejectFollowUser(array $activity)
1956         {
1957                 $uid = User::getIdForURL($activity['object_actor']);
1958                 if (empty($uid)) {
1959                         return;
1960                 }
1961
1962                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1963                 if (empty($cid)) {
1964                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1965                         return;
1966                 }
1967
1968                 self::switchContact($cid);
1969
1970                 $contact = Contact::getById($cid, ['rel']);
1971                 if ($contact['rel'] == Contact::SHARING) {
1972                         Contact::remove($cid);
1973                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1974                 } elseif ($contact['rel'] == Contact::FRIEND) {
1975                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1976                 } else {
1977                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1978                 }
1979                 Queue::remove($activity);
1980         }
1981
1982         /**
1983          * Undo activity like "like" or "dislike"
1984          *
1985          * @param array $activity
1986          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1987          * @throws \ImagickException
1988          */
1989         public static function undoActivity(array $activity)
1990         {
1991                 if (empty($activity['object_id'])) {
1992                         return;
1993                 }
1994
1995                 if (empty($activity['object_actor'])) {
1996                         return;
1997                 }
1998
1999                 $author_id = Contact::getIdForURL($activity['object_actor']);
2000                 if (empty($author_id)) {
2001                         return;
2002                 }
2003
2004                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => Item::GRAVITY_ACTIVITY]);
2005                 Queue::remove($activity);
2006         }
2007
2008         /**
2009          * Activity to remove a follower
2010          *
2011          * @param array $activity
2012          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2013          * @throws \ImagickException
2014          */
2015         public static function undoFollowUser(array $activity)
2016         {
2017                 $uid = User::getIdForURL($activity['object_object']);
2018                 if (empty($uid)) {
2019                         return;
2020                 }
2021
2022                 $owner = User::getOwnerDataById($uid);
2023                 if (empty($owner)) {
2024                         return;
2025                 }
2026
2027                 $cid = Contact::getIdForURL($activity['actor'], $uid);
2028                 if (empty($cid)) {
2029                         Logger::info('No contact found', ['actor' => $activity['actor']]);
2030                         return;
2031                 }
2032
2033                 self::switchContact($cid);
2034
2035                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
2036                 if (!DBA::isResult($contact)) {
2037                         return;
2038                 }
2039
2040                 Contact::removeFollower($contact);
2041                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
2042                 Queue::remove($activity);
2043         }
2044
2045         /**
2046          * Switches a contact to AP if needed
2047          *
2048          * @param integer $cid Contact ID
2049          * @return void
2050          * @throws \Exception
2051          */
2052         private static function switchContact(int $cid)
2053         {
2054                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
2055                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
2056                         return;
2057                 }
2058
2059                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
2060                 Contact::updateFromProbe($cid);
2061         }
2062
2063         /**
2064          * Collects implicit mentions like:
2065          * - the author of the parent item
2066          * - all the mentioned conversants in the parent item
2067          *
2068          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
2069          * @return array
2070          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2071          */
2072         private static function getImplicitMentionList(array $parent): array
2073         {
2074                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
2075
2076                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
2077
2078                 $implicit_mentions = [];
2079                 if (empty($parent_author['url'])) {
2080                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
2081                 } else {
2082                         $implicit_mentions[] = $parent_author['url'];
2083                         $implicit_mentions[] = $parent_author['nurl'];
2084                         $implicit_mentions[] = $parent_author['alias'];
2085                 }
2086
2087                 if (!empty($parent['alias'])) {
2088                         $implicit_mentions[] = $parent['alias'];
2089                 }
2090
2091                 foreach ($parent_terms as $term) {
2092                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
2093                         if (!empty($contact['url'])) {
2094                                 $implicit_mentions[] = $contact['url'];
2095                                 $implicit_mentions[] = $contact['nurl'];
2096                                 $implicit_mentions[] = $contact['alias'];
2097                         }
2098                 }
2099
2100                 return $implicit_mentions;
2101         }
2102
2103         /**
2104          * Strips from the body prepended implicit mentions
2105          *
2106          * @param string $body
2107          * @param array $parent
2108          * @return string
2109          */
2110         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
2111         {
2112                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
2113                         return $body;
2114                 }
2115
2116                 $potential_mentions = self::getImplicitMentionList($parent);
2117
2118                 $kept_mentions = [];
2119
2120                 // Extract one prepended mention at a time from the body
2121                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
2122                         if (!in_array($matches[2], $potential_mentions)) {
2123                                 $kept_mentions[] = $matches[1];
2124                         }
2125
2126                         $body = $matches[3];
2127                 }
2128
2129                 // Re-appending the kept mentions to the body after extraction
2130                 $kept_mentions[] = $body;
2131
2132                 return implode('', $kept_mentions);
2133         }
2134
2135         /**
2136          * Adds links to string mentions
2137          *
2138          * @param string $body
2139          * @param array  $tags
2140          * @return string
2141          */
2142         protected static function addMentionLinks(string $body, array $tags): string
2143         {
2144                 // This prevents links to be added again to Pleroma-style mention links
2145                 $body = self::normalizeMentionLinks($body);
2146
2147                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
2148                         foreach ($tags as $tag) {
2149                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
2150                                         continue;
2151                                 }
2152
2153                                 $hash = substr($tag['name'], 0, 1);
2154                                 $name = substr($tag['name'], 1);
2155                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
2156                                         $hash = '';
2157                                         $name = $tag['name'];
2158                                 }
2159
2160                                 if (Network::isValidHttpUrl($tag['href'])) {
2161                                         $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
2162                                 }
2163                         }
2164
2165                         return $body;
2166                 });
2167
2168                 return $body;
2169         }
2170 }