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) && ($item['thr-parent'] != $result) && Post::exists(['uri' => $result])) {
 352                                 $item['thr-parent'] = $result;
 353                         }
 354                 }
 355
 356                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 357
 358                 if (empty($conversation) && empty($activity['directmessage']) && ($item['gravity'] != Item::GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 359                         Logger::notice('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 360                         if (!$fetch_parents) {
 361                                 Queue::remove($activity);
 362                         }
 363                         return [];
 364                 }
 365
 366                 $item['network'] = Protocol::ACTIVITYPUB;
 367                 $item['author-link'] = $activity['author'];
 368                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 369                 $item['owner-link'] = $activity['actor'];
 370                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 371
 372                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 373                         $item['private'] = Item::UNLISTED;
 374                 } elseif (in_array(0, $activity['receiver'])) {
 375                         $item['private'] = Item::PUBLIC;
 376                 } else {
 377                         $item['private'] = Item::PRIVATE;
 378                 }
 379
 380                 if (!empty($activity['raw'])) {
 381                         $item['source'] = $activity['raw'];
 382                 }
 383
 384                 $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 385
 386                 if (isset($activity['push'])) {
 387                         $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 388                 }
 389
 390                 if (!empty($activity['from-relay'])) {
 391                         $item['direction'] = Conversation::RELAY;
 392                 }
 393
 394                 if ($activity['object_type'] == 'as:Article') {
 395                         $item['post-type'] = Item::PT_ARTICLE;
 396                 } elseif ($activity['object_type'] == 'as:Audio') {
 397                         $item['post-type'] = Item::PT_AUDIO;
 398                 } elseif ($activity['object_type'] == 'as:Document') {
 399                         $item['post-type'] = Item::PT_DOCUMENT;
 400                 } elseif ($activity['object_type'] == 'as:Event') {
 401                         $item['post-type'] = Item::PT_EVENT;
 402                 } elseif ($activity['object_type'] == 'as:Image') {
 403                         $item['post-type'] = Item::PT_IMAGE;
 404                 } elseif ($activity['object_type'] == 'as:Page') {
 405                         $item['post-type'] = Item::PT_PAGE;
 406                 } elseif ($activity['object_type'] == 'as:Question') {
 407                         $item['post-type'] = Item::PT_POLL;
 408                 } elseif ($activity['object_type'] == 'as:Video') {
 409                         $item['post-type'] = Item::PT_VIDEO;
 410                 } else {
 411                         $item['post-type'] = Item::PT_NOTE;
 412                 }
 413
 414                 $item['isGroup'] = false;
 415
 416                 if (!empty($activity['thread-completion'])) {
 417                         if ($activity['thread-completion'] != $item['owner-id']) {
 418                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 419                                 $item['causer-link'] = $actor['url'];
 420                                 $item['causer-id']   = $activity['thread-completion'];
 421                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 422                         } else {
 423                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 424                                 $item['causer-link'] = $item['owner-link'];
 425                                 $item['causer-id']   = $item['owner-id'];
 426                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 427                         }
 428
 429                         $item['owner-link'] = $item['author-link'];
 430                         $item['owner-id']   = $item['author-id'];
 431                 }
 432
 433                 if (!$item['isGroup'] && !empty($activity['receiver_urls']['as:audience'])) {
 434                         foreach ($activity['receiver_urls']['as:audience'] as $audience) {
 435                                 $actor = APContact::getByURL($audience, false);
 436                                 if (($actor['type'] ?? 'Person') == 'Group') {
 437                                         Logger::debug('Group post detected via audience.', ['audience' => $audience, 'actor' => $activity['actor'], 'author' => $activity['author']]);
 438                                         $item['isGroup']    = true;
 439                                         $item['group-link'] = $item['owner-link'] = $audience;
 440                                         $item['owner-id']   = Contact::getIdForURL($audience);
 441                                         break;
 442                                 }
 443                         }
 444                 } else {
 445                         $owner = APContact::getByURL($item['owner-link'], false);
 446                 }
 447
 448                 if (!$item['isGroup'] && (($owner['type'] ?? 'Person') == 'Group')) {
 449                         Logger::debug('Group post detected via owner.', ['actor' => $activity['actor'], 'author' => $activity['author']]);
 450                         $item['isGroup']    = true;
 451                         $item['group-link'] = $item['owner-link'];
 452                 } elseif (!empty($item['causer-link'])) {
 453                         $causer = APContact::getByURL($item['causer-link'], false);
 454                 }
 455
 456                 if (!$item['isGroup'] && (($causer['type'] ?? 'Person') == 'Group')) {
 457                         Logger::debug('Group post detected via causer.', ['actor' => $activity['actor'], 'author' => $activity['author'], 'causer' => $item['causer-link']]);
 458                         $item['isGroup']    = true;
 459                         $item['group-link'] = $item['causer-link'];
 460                 }
 461
 462                 if (!empty($item['group-link']) && empty($item['causer-link'])) {
 463                         $item['causer-link'] = $item['group-link'];
 464                         $item['causer-id']   = Contact::getIdForURL($item['causer-link']);
 465                 }
 466
 467                 $item['uri'] = $activity['id'];
 468
 469                 if (empty($activity['published']) || empty($activity['updated'])) {
 470                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity]);
 471                 }
 472
 473                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 474                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 475                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 476                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 477
 478                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 479                 if (empty($item['uri-id'])) {
 480                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 481                         return [];
 482                 }
 483
 484                 $item['thr-parent-id'] = ItemURI::getIdByURI($item['thr-parent']);
 485
 486                 $item = self::processContent($activity, $item);
 487                 if (empty($item)) {
 488                         Logger::info('Message was not processed');
 489                         Queue::remove($activity);
 490                         return [];
 491                 }
 492
 493                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 494
 495                 self::storeAttachments($activity, $item);
 496                 self::storeQuestion($activity, $item);
 497
 498                 // We received the post via AP, so we set the protocol of the server to AP
 499                 $contact = Contact::getById($item['author-id'], ['gsid']);
 500                 if (!empty($contact['gsid'])) {
 501                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 502                 }
 503
 504                 if ($item['author-id'] != $item['owner-id']) {
 505                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 506                         if (!empty($contact['gsid'])) {
 507                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 508                         }
 509                 }
 510
 511                 return $item;
 512         }
 513
 514         /**
 515          * Fetch and process parent posts for the given activity
 516          *
 517          * @param array $activity
 518          * @param bool  $in_background
 519          *
 520          * @return string
 521          */
 522         private static function fetchParent(array $activity, bool $in_background = false): string
 523         {
 524                 if (self::isFetched($activity['reply-to-id'])) {
 525                         Logger::info('Id is already fetched', ['id' => $activity['reply-to-id']]);
 526                         return '';
 527                 }
 528
 529                 self::addActivityId($activity['reply-to-id']);
 530
 531                 $completion = $activity['completion-mode'] ?? Receiver::COMPLETION_NONE;
 532
 533                 if (DI::config()->get('system', 'decoupled_receiver') && ($completion != Receiver::COMPLETION_MANUAL)) {
 534                         $in_background = true;
 535                 }
 536
 537                 $recursion_depth = $activity['recursion-depth'] ?? 0;
 538
 539                 if (!$in_background && ($recursion_depth < DI::config()->get('system', 'max_recursion_depth'))) {
 540                         Logger::info('Parent not found. Try to refetch it.', ['completion' => $completion, 'recursion-depth' => $recursion_depth, 'parent' => $activity['reply-to-id']]);
 541                         $result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 542                         if (empty($result) && self::isActivityGone($activity['reply-to-id'])) {
 543                                 Logger::notice('The activity is gone, the queue entry will be deleted', ['parent' => $activity['reply-to-id']]);
 544                                 if (!empty($activity['entry-id'])) {
 545                                         Queue::deleteById($activity['entry-id']);
 546                                 }
 547                         } elseif (!empty($result)) {
 548                                 $post = Post::selectFirstPost(['uri'], ['uri' => [$result, $activity['reply-to-id']]]);
 549                                 if (!empty($post['uri'])) {
 550                                         Logger::info('The activity has been fetched and created.', ['result' => $result, 'uri' => $post['uri']]);
 551                                         return $post['uri'];
 552                                 } else {
 553                                         Logger::notice('The activity exists but has not been created, the queue entry will be deleted.', ['parent' => $result]);
 554                                         if (!empty($activity['entry-id'])) {
 555                                                 Queue::deleteById($activity['entry-id']);
 556                                         }
 557                                 }
 558                         }
 559                         return '';
 560                 } elseif (self::isActivityGone($activity['reply-to-id'])) {
 561                         Logger::notice('The activity is gone. We will not spawn a worker. The queue entry will be deleted', ['parent' => $activity['reply-to-id']]);
 562                         if ($in_background) {
 563                                 // fetching in background is done for all activities where we have got the conversation
 564                                 // There we only delete the single activity and not the whole thread since we can store the
 565                                 // other posts in the thread even with missing posts.
 566                                 Queue::remove($activity);
 567                         } elseif (!empty($activity['entry-id'])) {
 568                                 Queue::deleteById($activity['entry-id']);
 569                         }
 570                         return '';
 571                 } elseif ($in_background) {
 572                         Logger::notice('Fetching is done in the background.', ['parent' => $activity['reply-to-id']]);
 573                 } else {
 574                         Logger::notice('Recursion level is too high.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 575                 }
 576
 577                 if (!Fetch::hasWorker($activity['reply-to-id'])) {
 578                         Logger::notice('Fetching is done by worker.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 579                         Fetch::add($activity['reply-to-id']);
 580                         $activity['recursion-depth'] = 0;
 581                         $wid = Worker::add(Worker::PRIORITY_HIGH, 'FetchMissingActivity', $activity['reply-to-id'], $activity, '', Receiver::COMPLETION_ASYNC);
 582                         Fetch::setWorkerId($activity['reply-to-id'], $wid);
 583                 } else {
 584                         Logger::debug('Activity will already be fetched via a worker.', ['url' => $activity['reply-to-id']]);
 585                 }
 586
 587                 return '';
 588         }
 589
 590         /**
 591          * Check if a given activity is no longer available
 592          *
 593          * @param string $url
 594          *
 595          * @return boolean
 596          */
 597         public static function isActivityGone(string $url): bool
 598         {
 599                 try {
 600                         $curlResult = HTTPSignature::fetchRaw($url, 0);
 601                 } catch (\Exception $exception) {
 602                         Logger::notice('Error fetching url', ['url' => $url, 'exception' => $exception]);
 603                         return true;
 604                 }
 605
 606                 if (Network::isUrlBlocked($url)) {
 607                         return true;
 608                 }
 609
 610                 // @todo To ensure that the remote system is working correctly, we can check if the "Content-Type" contains JSON
 611                 if (in_array($curlResult->getReturnCode(), [401, 404])) {
 612                         return true;
 613                 }
 614
 615                 if ($curlResult->isSuccess()) {
 616                         $object = json_decode($curlResult->getBody(), true);
 617                         if (!empty($object)) {
 618                                 $activity = JsonLD::compact($object);
 619                                 if (JsonLD::fetchElement($activity, '@type') == 'as:Tombstone') {
 620                                         return true;
 621                                 }
 622                         }
 623                 } elseif ($curlResult->getReturnCode() == 0) {
 624                         $host = parse_url($url, PHP_URL_HOST);
 625                         if (!(filter_var($host, FILTER_VALIDATE_IP) || @dns_get_record($host . '.', DNS_A + DNS_AAAA))) {
 626                                 return true;
 627                         }
 628                 }
 629
 630                 return false;
 631         }
 632         /**
 633          * Delete items
 634          *
 635          * @param array $activity
 636          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 637          * @throws \ImagickException
 638          */
 639         public static function deleteItem(array $activity)
 640         {
 641                 $owner = Contact::getIdForURL($activity['actor']);
 642
 643                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 644                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 645                 Queue::remove($activity);
 646         }
 647
 648         /**
 649          * Prepare the item array for an activity
 650          *
 651          * @param array $activity Activity array
 652          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 653          * @throws \ImagickException
 654          */
 655         public static function addTag(array $activity)
 656         {
 657                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 658                         return;
 659                 }
 660
 661                 foreach ($activity['receiver'] as $receiver) {
 662                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 663                         if (!DBA::isResult($item)) {
 664                                 // We don't fetch missing content for this purpose
 665                                 continue;
 666                         }
 667
 668                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 669                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 670                                 continue;
 671                         }
 672
 673                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 674                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 675                 }
 676         }
 677
 678         /**
 679          * Prepare the item array for an activity
 680          *
 681          * @param array      $activity   Activity array
 682          * @param string     $verb       Activity verb
 683          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 684          * @throws \ImagickException
 685          */
 686         public static function createActivity(array $activity, string $verb)
 687         {
 688                 $activity['reply-to-id'] = $activity['object_id'];
 689                 $item = self::createItem($activity, false);
 690                 if (empty($item)) {
 691                         Logger::debug('Activity was not prepared', ['id' => $activity['object_id']]);
 692                         return;
 693                 }
 694
 695                 $item['verb'] = $verb;
 696                 $item['thr-parent'] = $activity['object_id'];
 697                 $item['gravity'] = Item::GRAVITY_ACTIVITY;
 698                 unset($item['post-type']);
 699                 $item['object-type'] = Activity\ObjectType::NOTE;
 700
 701                 if (!empty($activity['content'])) {
 702                         $item['body'] = HTML::toBBCode($activity['content']);
 703                 }
 704
 705                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 706
 707                 self::postItem($activity, $item);
 708         }
 709
 710         /**
 711          * Fetch the Uri-Id of a post for the "featured" collection
 712          *
 713          * @param array $activity
 714          * @return null|array
 715          */
 716         private static function getUriIdForFeaturedCollection(array $activity)
 717         {
 718                 $actor = APContact::getByURL($activity['actor']);
 719                 if (empty($actor)) {
 720                         return null;
 721                 }
 722
 723                 // Refetch the account when the "featured" collection is missing.
 724                 // This can be removed in a future version (end of 2022 should be good).
 725                 if (empty($actor['featured'])) {
 726                         $actor = APContact::getByURL($activity['actor'], true);
 727                         if (empty($actor)) {
 728                                 return null;
 729                         }
 730                 }
 731
 732                 $parent = Post::selectFirst(['uri-id', 'author-id'], ['uri' => $activity['object_id']]);
 733                 if (empty($parent['uri-id'])) {
 734                         if (self::fetchMissingActivity($activity['object_id'], $activity, '', Receiver::COMPLETION_AUTO)) {
 735                                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 736                         }
 737                 }
 738
 739                 if (!empty($parent['uri-id'])) {
 740                         $parent;
 741                 }
 742
 743                 return null;
 744         }
 745
 746         /**
 747          * Add a post to the "Featured" collection
 748          *
 749          * @param array $activity
 750          */
 751         public static function addToFeaturedCollection(array $activity)
 752         {
 753                 $post = self::getUriIdForFeaturedCollection($activity);
 754                 if (empty($post)) {
 755                         return;
 756                 }
 757
 758                 Logger::debug('Add post to featured collection', ['post' => $post]);
 759
 760                 Post\Collection::add($post['uri-id'], Post\Collection::FEATURED, $post['author-id']);
 761                 Queue::remove($activity);
 762         }
 763
 764         /**
 765          * Remove a post to the "Featured" collection
 766          *
 767          * @param array $activity
 768          */
 769         public static function removeFromFeaturedCollection(array $activity)
 770         {
 771                 $post = self::getUriIdForFeaturedCollection($activity);
 772                 if (empty($post)) {
 773                         return;
 774                 }
 775
 776                 Logger::debug('Remove post from featured collection', ['post' => $post]);
 777
 778                 Post\Collection::remove($post['uri-id'], Post\Collection::FEATURED);
 779                 Queue::remove($activity);
 780         }
 781
 782         /**
 783          * Create an event
 784          *
 785          * @param array $activity Activity array
 786          * @param array $item
 787          *
 788          * @return int event id
 789          * @throws \Exception
 790          */
 791         public static function createEvent(array $activity, array $item): int
 792         {
 793                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 794                 $event['desc']      = HTML::toBBCode($activity['content'] ?? '');
 795                 if (!empty($activity['start-time'])) {
 796                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 797                 }
 798                 if (!empty($activity['end-time'])) {
 799                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 800                 }
 801                 $event['nofinish']  = empty($event['finish']);
 802                 $event['location']  = $activity['location'];
 803                 $event['cid']       = $item['contact-id'];
 804                 $event['uid']       = $item['uid'];
 805                 $event['uri']       = $item['uri'];
 806                 $event['edited']    = $item['edited'];
 807                 $event['private']   = $item['private'];
 808                 $event['guid']      = $item['guid'];
 809                 $event['plink']     = $item['plink'];
 810                 $event['network']   = $item['network'];
 811                 $event['protocol']  = $item['protocol'];
 812                 $event['direction'] = $item['direction'];
 813                 $event['source']    = $item['source'];
 814
 815                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 816                 if (DBA::isResult($ev)) {
 817                         $event['id'] = $ev['id'];
 818                 }
 819
 820                 $event_id = Event::store($event);
 821
 822                 Logger::info('Event was stored', ['id' => $event_id]);
 823
 824                 return $event_id;
 825         }
 826
 827         /**
 828          * Process the content
 829          *
 830          * @param array $activity Activity array
 831          * @param array $item
 832          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 833          * @throws \Exception
 834          */
 835         private static function processContent(array $activity, array $item)
 836         {
 837                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 838                         $item['title'] = strip_tags($activity['name'] ?? '');
 839                         $content = Markdown::toBBCode($activity['content']);
 840                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 841                         $item['title'] = $activity['name'];
 842                         $content = $activity['content'];
 843                 } else {
 844                         // By default assume "text/html"
 845                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 846                         $content = HTML::toBBCode($activity['content'] ?? '');
 847                 }
 848
 849                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 850
 851                 if (!empty($activity['languages'])) {
 852                         $item['language'] = self::processLanguages($activity['languages']);
 853                 }
 854
 855                 if (!empty($activity['emojis'])) {
 856                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 857                 }
 858
 859                 $content = self::addMentionLinks($content, $activity['tags']);
 860
 861                 if (!empty($activity['quote-url'])) {
 862                         $id = Item::fetchByLink($activity['quote-url'], 0, ActivityPub\Receiver::COMPLETION_ASYNC);
 863                         if ($id) {
 864                                 $shared_item = Post::selectFirst(['uri-id'], ['id' => $id]);
 865                                 $item['quote-uri-id'] = $shared_item['uri-id'];
 866                         } elseif ($uri_id = ItemURI::getIdByURI($activity['quote-url'], false)) {
 867                                 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]);
 868                                 $item['quote-uri-id'] = $uri_id;
 869                         } else {
 870                                 Logger::info('Quote was not fetched', ['guid' => $item['guid'], 'uri-id' => $item['uri-id'], 'quote' => $activity['quote-url']]);
 871                         }
 872                 }
 873
 874                 if (!empty($activity['source'])) {
 875                         $item['body'] = $activity['source'];
 876                         $item['raw-body'] = $content;
 877
 878                         $quote_uri_id = Item::getQuoteUriId($item['body']);
 879                         if (empty($item['quote-uri-id']) && !empty($quote_uri_id)) {
 880                                 $item['quote-uri-id'] = $quote_uri_id;
 881                         }
 882
 883                         $item['body'] = BBCode::removeSharedData($item['body']);
 884                 } else {
 885                         $parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
 886                         if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == Item::GRAVITY_COMMENT)) {
 887                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 888                                 if (!DBA::isResult($parent)) {
 889                                         Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
 890                                         return false;
 891                                 }
 892                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 893                         }
 894                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 895                         $item['raw-body'] = $item['body'] = $content;
 896                 }
 897
 898                 if (!empty($item['author-id']) && ($item['author-id'] == $item['owner-id'])) {
 899                         foreach (Tag::getFromBody($item['body'], Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION]) as $tag) {
 900                                 $actor = APContact::getByURL($tag[2], false);
 901                                 if (($actor['type'] ?? 'Person') == 'Group') {
 902                                         Logger::debug('Group post detected via exclusive mention.', ['mention' => $actor['url'], 'actor' => $activity['actor'], 'author' => $activity['author']]);
 903                                         $item['isGroup']    = true;
 904                                         $item['group-link'] = $item['owner-link'] = $actor['url'];
 905                                         $item['owner-id']   = Contact::getIdForURL($actor['url']);
 906                                         break;
 907                                 }
 908                         }
 909                 }
 910
 911                 self::storeFromBody($item);
 912                 self::storeTags($item['uri-id'], $activity['tags']);
 913
 914                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 915
 916                 $item['location'] = $activity['location'];
 917
 918                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 919                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 920                 }
 921
 922                 $item['app'] = $activity['generator'];
 923
 924                 return $item;
 925         }
 926
 927         /**
 928          * Store hashtags and mentions
 929          *
 930          * @param array $item
 931          */
 932         private static function storeFromBody(array $item)
 933         {
 934                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 935                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 936
 937                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 938         }
 939
 940         /**
 941          * Generate a GUID out of an URL of an ActivityPub post.
 942          *
 943          * @param string $url message URL
 944          * @return string with GUID
 945          */
 946         private static function getGUIDByURL(string $url): string
 947         {
 948                 $parsed = parse_url($url);
 949
 950                 $host_hash = hash('crc32', $parsed['host']);
 951
 952                 unset($parsed["scheme"]);
 953                 unset($parsed["host"]);
 954
 955                 $path = implode("/", $parsed);
 956
 957                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 958         }
 959
 960         /**
 961          * Checks if an incoming message is wanted
 962          *
 963          * @param array $activity
 964          * @param array $item
 965          * @return boolean Is the message wanted?
 966          */
 967         private static function isSolicitedMessage(array $activity, array $item): bool
 968         {
 969                 // The checks are split to improve the support when searching why a message was accepted.
 970                 if (count($activity['receiver']) != 1) {
 971                         // The message has more than one receiver, so it is wanted.
 972                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 973                         return true;
 974                 }
 975
 976                 if ($item['private'] == Item::PRIVATE) {
 977                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 978                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 979                         return true;
 980                 }
 981
 982                 if (!empty($activity['from-relay'])) {
 983                         // We check relay posts at another place. When it arrived here, the message is already checked.
 984                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 985                         return true;
 986                 }
 987
 988                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUNCE])) {
 989                         // Manual completions and completions caused by reshares are allowed without any further checks.
 990                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 991                         return true;
 992                 }
 993
 994                 if ($item['gravity'] != Item::GRAVITY_PARENT) {
 995                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 996                         // This can possibly be improved in the future.
 997                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 998                         return true;
 999                 }
1000
1001                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
1002                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB, $activity['thread-completion'] ?? 0)) {
1003                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
1004                         return true;
1005                 } else {
1006                         return false;
1007                 }
1008         }
1009
1010         /**
1011          * Creates an item post
1012          *
1013          * @param array $activity Activity data
1014          * @param array $item     item array
1015          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1016          * @throws \ImagickException
1017          */
1018         public static function postItem(array $activity, array $item)
1019         {
1020                 if (empty($item)) {
1021                         return;
1022                 }
1023
1024                 $stored = false;
1025                 $success = false;
1026                 ksort($activity['receiver']);
1027
1028                 if (!self::isSolicitedMessage($activity, $item)) {
1029                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
1030                         if (!empty($activity['entry-id'])) {
1031                                 Queue::deleteById($activity['entry-id']);
1032                         }
1033                         return;
1034                 }
1035
1036                 foreach ($activity['receiver'] as $receiver) {
1037                         if ($receiver == -1) {
1038                                 continue;
1039                         }
1040
1041                         if (($receiver != 0) && empty($item['parent-uri-id']) && !empty($item['thr-parent-id'])) {
1042                                 $parent = Post::selectFirst(['parent-uri-id', 'parent-uri'], ['uri-id' => $item['thr-parent-id'], 'uid' => [0, $receiver]]);
1043                                 if (!empty($parent['parent-uri-id'])) {
1044                                         $item['parent-uri-id'] = $parent['parent-uri-id'];
1045                                         $item['parent-uri']    = $parent['parent-uri'];
1046                                 }
1047                         }
1048
1049                         $item['uid'] = $receiver;
1050
1051                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
1052                         switch($type) {
1053                                 case Receiver::TARGET_TO:
1054                                         $item['post-reason'] = Item::PR_TO;
1055                                         break;
1056                                 case Receiver::TARGET_CC:
1057                                         $item['post-reason'] = Item::PR_CC;
1058                                         break;
1059                                 case Receiver::TARGET_BTO:
1060                                         $item['post-reason'] = Item::PR_BTO;
1061                                         break;
1062                                 case Receiver::TARGET_BCC:
1063                                         $item['post-reason'] = Item::PR_BCC;
1064                                         break;
1065                                 case Receiver::TARGET_AUDIENCE:
1066                                         $item['post-reason'] = Item::PR_AUDIENCE;
1067                                         break;
1068                                 case Receiver::TARGET_FOLLOWER:
1069                                         $item['post-reason'] = Item::PR_FOLLOWER;
1070                                         break;
1071                                 case Receiver::TARGET_ANSWER:
1072                                         $item['post-reason'] = Item::PR_COMMENT;
1073                                         break;
1074                                 case Receiver::TARGET_GLOBAL:
1075                                         $item['post-reason'] = Item::PR_GLOBAL;
1076                                         break;
1077                                 default:
1078                                         $item['post-reason'] = Item::PR_NONE;
1079                         }
1080
1081                         $item['post-reason'] = Item::getPostReason($item);
1082
1083                         if (in_array($item['post-reason'], [Item::PR_GLOBAL, Item::PR_NONE])) {
1084                                 if (!empty($activity['from-relay'])) {
1085                                         $item['post-reason'] = Item::PR_RELAY;
1086                                 } elseif (!empty($activity['thread-completion'])) {
1087                                         $item['post-reason'] = Item::PR_FETCHED;
1088                                 } elseif (!empty($activity['push'])) {
1089                                         $item['post-reason'] = Item::PR_PUSHED;
1090                                 }
1091                         } elseif (($item['post-reason'] == Item::PR_FOLLOWER) && !empty($activity['from-relay'])) {
1092                                 // When a post arrives via a relay and we follow the author, we have to override the causer.
1093                                 // Otherwise the system assumes that we follow the relay. (See "addRowInformation")
1094                                 Logger::debug('Relay post for follower', ['receiver' => $receiver, 'guid' => $item['guid'], 'relay' => $activity['from-relay']]);
1095                                 $item['causer-id'] = ($item['gravity'] == Item::GRAVITY_PARENT) ? $item['owner-id'] : $item['author-id'];
1096                         }
1097
1098                         if ($item['isGroup']) {
1099                                 $item['contact-id'] = Contact::getIdForURL($item['group-link'], $receiver);
1100                         } else {
1101                                 $item['contact-id'] = Contact::getIdForURL($item['author-link'], $receiver);
1102                         }
1103
1104                         if (($receiver != 0) && empty($item['contact-id'])) {
1105                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
1106                         }
1107
1108                         if (!empty($activity['directmessage']) && self::postMail($item)) {
1109                                 continue;
1110                         }
1111
1112                         if (($receiver != 0) && ($item['gravity'] == Item::GRAVITY_PARENT) && !in_array($item['post-reason'], [Item::PR_FOLLOWER, Item::PR_TAG, item::PR_TO, Item::PR_CC, Item::PR_AUDIENCE])) {
1113                                 if (!$item['isGroup']) {
1114                                         if ($item['post-reason'] == Item::PR_BCC) {
1115                                                 Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id'], 'url' => $item['uri']]);
1116                                                 continue;
1117                                         }
1118
1119                                         if ((DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE)
1120                                                 && in_array($activity['thread-children-type'] ?? '', Receiver::ACTIVITY_TYPES)) {
1121                                                 Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
1122                                                         ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
1123                                                 continue;
1124                                         }
1125                                 }
1126
1127                                 $isGroup = false;
1128                                 $user = User::getById($receiver, ['account-type']);
1129                                 if (!empty($user['account-type'])) {
1130                                         $isGroup = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
1131                                 }
1132
1133                                 if ((DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE)
1134                                         && ((!$isGroup && !$item['isGroup'] && ($activity['type'] != 'as:Announce'))
1135                                         || !Contact::isSharingByURL($activity['actor'], $receiver))) {
1136                                         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']]);
1137                                         continue;
1138                                 }
1139
1140                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
1141                         }
1142
1143                         if (!self::hasParents($item, $receiver)) {
1144                                 continue;
1145                         }
1146
1147                         if (($item['gravity'] != Item::GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
1148                                 $event_id = self::createEvent($activity, $item);
1149
1150                                 $item = Event::getItemArrayForImportedId($event_id, $item);
1151                         }
1152
1153                         $item_id = Item::insert($item);
1154                         if ($item_id) {
1155                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
1156                                 $success = true;
1157                         } else {
1158                                 Logger::notice('Item insertion aborted', ['uri' => $item['uri'], 'uid' => $item['uid']]);
1159                                 if (($item['uid'] == 0) && (count($activity['receiver']) > 1)) {
1160                                         Logger::info('Public item was aborted. We skip for all users.', ['uri' => $item['uri']]);
1161                                         break;
1162                                 }
1163                         }
1164
1165                         if ($item['uid'] == 0) {
1166                                 $stored = $item_id;
1167                         }
1168                 }
1169
1170                 Queue::remove($activity);
1171
1172                 if ($success && Queue::hasChildren($item['uri']) && Post::exists(['uri' => $item['uri']])) {
1173                         Queue::processReplyByUri($item['uri']);
1174                 }
1175
1176                 // Store send a follow request for every reshare - but only when the item had been stored
1177                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == Item::GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
1178                         $author = APContact::getByURL($item['owner-link'], false);
1179                         // We send automatic follow requests for reshared messages. (We don't need though for group posts)
1180                         if ($author['type'] != 'Group') {
1181                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
1182                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
1183                         }
1184                 }
1185         }
1186
1187         /**
1188          * Checks if there are parent posts for the given receiver.
1189          * If not, then the system will try to add them.
1190          *
1191          * @param array $item
1192          * @param integer $receiver
1193          * @return boolean
1194          */
1195         private static function hasParents(array $item, int $receiver)
1196         {
1197                 if (($receiver == 0) || ($item['gravity'] == Item::GRAVITY_PARENT)) {
1198                         return true;
1199                 }
1200
1201                 $fields = ['causer-id' => $item['causer-id'] ?? $item['author-id'], 'post-reason' => Item::PR_FETCHED];
1202
1203                 $add_parent = true;
1204
1205                 if ($item['verb'] != Activity::ANNOUNCE) {
1206                         switch (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer')) {
1207                                 case Item::COMPLETION_COMMENT:
1208                                         $add_parent = ($item['gravity'] != Item::GRAVITY_ACTIVITY);
1209                                         break;
1210
1211                                 case Item::COMPLETION_NONE:
1212                                         $add_parent = false;
1213                                         break;
1214                         }
1215                 }
1216
1217                 if ($add_parent) {
1218                         $add_parent = Contact::isSharing($fields['causer-id'], $receiver);
1219                         if (!$add_parent && ($item['author-id'] != $fields['causer-id'])) {
1220                                 $add_parent = Contact::isSharing($item['author-id'], $receiver);
1221                         }
1222                         if (!$add_parent && !in_array($item['owner-id'], [$fields['causer-id'], $item['author-id']])) {
1223                                 $add_parent = Contact::isSharing($item['owner-id'], $receiver);
1224                         }
1225                 }
1226
1227                 $has_parents = false;
1228
1229                 if (!empty($item['parent-uri-id'])) {
1230                         if (Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => $receiver])) {
1231                                 $has_parents = true;
1232                         } elseif ($add_parent && Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => 0])) {
1233                                 $stored = Item::storeForUserByUriId($item['parent-uri-id'], $receiver, $fields);
1234                                 $has_parents = (bool)$stored;
1235                                 if ($stored) {
1236                                         Logger::notice('Inserted missing parent post', ['stored' => $stored, 'uid' => $receiver, 'parent' => $item['parent-uri']]);
1237                                 } else {
1238                                         Logger::notice('Parent could not be added.', ['uid' => $receiver, 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1239                                         return false;
1240                                 }
1241                         } elseif ($add_parent) {
1242                                 Logger::debug('Parent does not exist.', ['uid' => $receiver, 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1243                         } else {
1244                                 Logger::debug('Parent should not be added.', ['uid' => $receiver, 'gravity' => $item['gravity'], 'verb' => $item['verb'], 'guid' => $item['guid'], 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1245                         }
1246                 }
1247
1248                 if (empty($item['parent-uri-id']) || ($item['thr-parent-id'] != $item['parent-uri-id'])) {
1249                         if (Post::exists(['uri-id' => $item['thr-parent-id'], 'uid' => $receiver])) {
1250                                 $has_parents = true;
1251                         } elseif (($has_parents || $add_parent) && Post::exists(['uri-id' => $item['thr-parent-id'], 'uid' => 0])) {
1252                                 $stored = Item::storeForUserByUriId($item['thr-parent-id'], $receiver, $fields);
1253                                 $has_parents = $has_parents || (bool)$stored;
1254                                 if ($stored) {
1255                                         Logger::notice('Inserted missing thread parent post', ['stored' => $stored, 'uid' => $receiver, 'thread-parent' => $item['thr-parent']]);
1256                                 } else {
1257                                         Logger::notice('Thread parent could not be added.', ['uid' => $receiver, 'uri' => $item['uri'], 'thread-parent' => $item['thr-parent']]);
1258                                 }
1259                         } elseif ($add_parent) {
1260                                 Logger::debug('Thread parent does not exist.', ['uid' => $receiver, 'uri' => $item['uri'], 'thread-parent' => $item['thr-parent']]);
1261                         } else {
1262                                 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']]);
1263                         }
1264                 }
1265
1266                 return $has_parents;
1267         }
1268
1269         /**
1270          * Store tags and mentions into the tag table
1271          *
1272          * @param integer $uriid
1273          * @param array $tags
1274          */
1275         private static function storeTags(int $uriid, array $tags = null)
1276         {
1277                 foreach ($tags as $tag) {
1278                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1279                                 continue;
1280                         }
1281
1282                         $hash = substr($tag['name'], 0, 1);
1283
1284                         if ($tag['type'] == 'Mention') {
1285                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
1286                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
1287                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
1288                                         $tag['name'] = substr($tag['name'], 1);
1289                                 }
1290                                 $type = Tag::IMPLICIT_MENTION;
1291
1292                                 if (!empty($tag['href'])) {
1293                                         $apcontact = APContact::getByURL($tag['href']);
1294                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
1295                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
1296                                         }
1297                                 }
1298                         } elseif ($tag['type'] == 'Hashtag') {
1299                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
1300                                         $tag['name'] = substr($tag['name'], 1);
1301                                 }
1302                                 $type = Tag::HASHTAG;
1303                         }
1304
1305                         if (empty($tag['name'])) {
1306                                 continue;
1307                         }
1308
1309                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
1310                 }
1311         }
1312
1313         public static function storeReceivers(int $uriid, array $receivers)
1314         {
1315                 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 => $type) {
1316                         if (!empty($receivers[$element])) {
1317                                 foreach ($receivers[$element] as $receiver) {
1318                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
1319                                                 $name = Receiver::PUBLIC_COLLECTION;
1320                                         } elseif ($path = parse_url($receiver, PHP_URL_PATH)) {
1321                                                 $name = trim($path, '/');
1322                                         } elseif ($host = parse_url($receiver, PHP_URL_HOST)) {
1323                                                 $name = $host;
1324                                         } else {
1325                                                 Logger::warning('Unable to coerce name from receiver', ['element' => $element, 'type' => $type, 'receiver' => $receiver]);
1326                                                 $name = '';
1327                                         }
1328
1329                                         $target = Tag::getTargetType($receiver);
1330                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
1331                                         Tag::store($uriid, $type, $name, $receiver, $target);
1332                                 }
1333                         }
1334                 }
1335         }
1336
1337         /**
1338          * Creates an mail post
1339          *
1340          * @param array $item item array
1341          * @return int|bool New mail table row id or false on error
1342          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1343          */
1344         private static function postMail(array $item): bool
1345         {
1346                 if (($item['gravity'] != Item::GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
1347                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
1348                         return false;
1349                 }
1350
1351                 if (!Contact::isFollower($item['contact-id'], $item['uid']) && !Contact::isSharing($item['contact-id'], $item['uid'])) {
1352                         Logger::info('Contact is not a sharer or follower, mail will be discarded.', ['item' => $item]);
1353                         return false;
1354                 }
1355
1356                 Logger::info('Direct Message', $item);
1357
1358                 $msg = [];
1359                 $msg['uid'] = $item['uid'];
1360
1361                 $msg['contact-id'] = $item['contact-id'];
1362
1363                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1364                 $msg['from-name'] = $contact['name'];
1365                 $msg['from-url'] = $contact['url'];
1366                 $msg['from-photo'] = $contact['photo'];
1367
1368                 $msg['uri'] = $item['uri'];
1369                 $msg['created'] = $item['created'];
1370
1371                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1372                 if (DBA::isResult($parent)) {
1373                         $msg['parent-uri'] = $parent['parent-uri'];
1374                         $msg['title'] = $parent['title'];
1375                 } else {
1376                         $msg['parent-uri'] = $item['thr-parent'];
1377
1378                         if (!empty($item['title'])) {
1379                                 $msg['title'] = $item['title'];
1380                         } elseif (!empty($item['content-warning'])) {
1381                                 $msg['title'] = $item['content-warning'];
1382                         } else {
1383                                 // Trying to generate a title out of the body
1384                                 $title = $item['body'];
1385
1386                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1387                                         $title = $matches[3];
1388                                 }
1389
1390                                 $title = trim(BBCode::toPlaintext($title));
1391
1392                                 if (strlen($title) > 20) {
1393                                         $title = substr($title, 0, 20) . '...';
1394                                 }
1395
1396                                 $msg['title'] = $title;
1397                         }
1398                 }
1399                 $msg['body'] = $item['body'];
1400
1401                 return Mail::insert($msg);
1402         }
1403
1404         /**
1405          * Fetch featured posts from a contact with the given url
1406          *
1407          * @param string $url
1408          * @return void
1409          */
1410         public static function fetchFeaturedPosts(string $url)
1411         {
1412                 Logger::info('Fetch featured posts', ['contact' => $url]);
1413
1414                 $apcontact = APContact::getByURL($url);
1415                 if (empty($apcontact['featured'])) {
1416                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1417                         return;
1418                 }
1419
1420                 $pcid = Contact::getIdForURL($url, 0, false);
1421                 if (empty($pcid)) {
1422                         Logger::notice('Contact not found', ['contact' => $url]);
1423                         return;
1424                 }
1425
1426                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1427                 if (!empty($posts)) {
1428                         $old_featured = array_column($posts, 'uri-id');
1429                 } else {
1430                         $old_featured = [];
1431                 }
1432
1433                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1434                 if (empty($featured)) {
1435                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1436
1437                         foreach ($old_featured as $uri_id) {
1438                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1439                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1440                         }
1441                         return;
1442                 }
1443
1444                 $new = 0;
1445                 $old = 0;
1446
1447                 foreach ($featured as $post) {
1448                         if (empty($post['id'])) {
1449                                 continue;
1450                         }
1451                         $id = Item::fetchByLink($post['id'], 0, ActivityPub\Receiver::COMPLETION_ASYNC);
1452                         if (!empty($id)) {
1453                                 $item = Post::selectFirst(['uri-id', 'featured', 'author-id'], ['id' => $id]);
1454                                 if (!empty($item['uri-id'])) {
1455                                         if (!$item['featured']) {
1456                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED, $item['author-id']);
1457                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1458                                                 $new++;
1459                                         } else {
1460                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1461                                                 $old++;
1462                                         }
1463
1464                                         $index = array_search($item['uri-id'], $old_featured);
1465                                         if (!($index === false)) {
1466                                                 unset($old_featured[$index]);
1467                                         }
1468                                 }
1469                         }
1470                 }
1471
1472                 foreach ($old_featured as $uri_id) {
1473                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1474                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1475                 }
1476
1477                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1478         }
1479
1480         public static function fetchCachedActivity(string $url, int $uid): array
1481         {
1482                 $cachekey = self::CACHEKEY_FETCH_ACTIVITY . $uid . ':' . hash('sha256', $url);
1483                 $object = DI::cache()->get($cachekey);
1484
1485                 if (!is_null($object)) {
1486                         if (!empty($object)) {
1487                                 Logger::debug('Fetch from cache', ['url' => $url, 'uid' => $uid]);
1488                         } else {
1489                                 Logger::debug('Fetch from negative cache', ['url' => $url, 'uid' => $uid]);
1490                         }
1491                         return $object;
1492                 }
1493
1494                 $object = ActivityPub::fetchContent($url, $uid);
1495                 if (empty($object)) {
1496                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
1497                         // We perform negative caching.
1498                         DI::cache()->set($cachekey, [], Duration::FIVE_MINUTES);
1499                         return [];
1500                 }
1501
1502                 if (empty($object['id'])) {
1503                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1504                         return [];
1505                 }
1506                 DI::cache()->set($cachekey, $object, Duration::FIVE_MINUTES);
1507
1508                 Logger::debug('Activity was fetched successfully', ['url' => $url, 'uid' => $uid]);
1509
1510                 return $object;
1511         }
1512
1513         /**
1514          * Fetches missing posts
1515          *
1516          * @param string     $url         message URL
1517          * @param array      $child       activity array with the child of this message
1518          * @param string     $relay_actor Relay actor
1519          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1520          * @param int        $uid         User id that is used to fetch the activity
1521          * @return string fetched message URL
1522          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1523          * @throws \ImagickException
1524          */
1525         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL, int $uid = 0): string
1526         {
1527                 $object = self::fetchCachedActivity($url, $uid);
1528                 if (empty($object)) {
1529                         return '';
1530                 }
1531
1532                 $signer = [];
1533
1534                 if (!empty($object['attributedTo'])) {
1535                         $attributed_to = $object['attributedTo'];
1536                         if (is_array($attributed_to)) {
1537                                 $compacted = JsonLD::compact($object);
1538                                 $attributed_to = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1539                         }
1540                         $signer[] = $attributed_to;
1541                 }
1542
1543                 if (!empty($object['actor'])) {
1544                         $object_actor = $object['actor'];
1545                 } elseif (!empty($attributed_to)) {
1546                         $object_actor = $attributed_to;
1547                 } else {
1548                         // Shouldn't happen
1549                         $object_actor = '';
1550                 }
1551
1552                 $signer[] = $object_actor;
1553
1554                 if (!empty($child['author'])) {
1555                         $actor = $child['author'];
1556                         $signer[] = $actor;
1557                 } else {
1558                         $actor = $object_actor;
1559                 }
1560
1561                 if (!empty($object['published'])) {
1562                         $published = $object['published'];
1563                 } elseif (!empty($child['published'])) {
1564                         $published = $child['published'];
1565                 } else {
1566                         $published = DateTimeFormat::utcNow();
1567                 }
1568
1569                 $activity = [];
1570                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1571                 unset($object['@context']);
1572                 $activity['id'] = $object['id'];
1573                 $activity['to'] = $object['to'] ?? [];
1574                 $activity['cc'] = $object['cc'] ?? [];
1575                 $activity['audience'] = $object['audience'] ?? [];
1576                 $activity['actor'] = $actor;
1577                 $activity['object'] = $object;
1578                 $activity['published'] = $published;
1579                 $activity['type'] = 'Create';
1580
1581                 $ldactivity = JsonLD::compact($activity);
1582
1583                 $ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 0;
1584
1585                 if ($object_actor != $actor) {
1586                         Contact::updateByUrlIfNeeded($object_actor);
1587                 }
1588
1589                 Contact::updateByUrlIfNeeded($actor);
1590
1591                 if (!empty($child['thread-completion'])) {
1592                         $ldactivity['thread-completion'] = $child['thread-completion'];
1593                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1594                 } else {
1595                         $ldactivity['thread-completion'] = Contact::getIdForURL($relay_actor ?: $actor);
1596                         $ldactivity['completion-mode']   = $completion;
1597                 }
1598
1599                 if ($completion == Receiver::COMPLETION_RELAY) {
1600                         $ldactivity['from-relay'] = $ldactivity['thread-completion'];
1601                         if (!self::acceptIncomingMessage($ldactivity, $object['id'])) {
1602                                 return '';
1603                         }
1604                 }
1605
1606                 if (!empty($child['thread-children-type'])) {
1607                         $ldactivity['thread-children-type'] = $child['thread-children-type'];
1608                 } elseif (!empty($child['type'])) {
1609                         $ldactivity['thread-children-type'] = $child['type'];
1610                 } else {
1611                         $ldactivity['thread-children-type'] = 'as:Create';
1612                 }
1613
1614                 if (($completion == Receiver::COMPLETION_RELAY) && Queue::exists($url, 'as:Create')) {
1615                         Logger::info('Activity has already been queued.', ['url' => $url, 'object' => $activity['id']]);
1616                 } elseif (ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer, '', $completion)) {
1617                         Logger::info('Activity had been fetched and processed.', ['url' => $url, 'entry' => $child['entry-id'] ?? 0, 'completion' => $completion, 'object' => $activity['id']]);
1618                 } else {
1619                         Logger::info('Activity had been fetched and will be processed later.', ['url' => $url, 'entry' => $child['entry-id'] ?? 0, 'completion' => $completion, 'object' => $activity['id']]);
1620                 }
1621
1622                 return $activity['id'];
1623         }
1624
1625         /**
1626          * Test if incoming relay messages should be accepted
1627          *
1628          * @param array $activity activity array
1629          * @param string $id      object ID
1630          * @return boolean true if message is accepted
1631          */
1632         private static function acceptIncomingMessage(array $activity, string $id): bool
1633         {
1634                 if (empty($activity['as:object'])) {
1635                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1636                         return true;
1637                 }
1638
1639                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1640                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1641                 if (Post::exists(['uri-id' => $uriid])) {
1642                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1643                         return true;
1644                 }
1645
1646                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1647                 $authorid = Contact::getIdForURL($attributed_to);
1648
1649                 $content = JsonLD::fetchElement($activity['as:object'], 'as:name', '@value') ?? '';
1650                 $content .= ' ' . JsonLD::fetchElement($activity['as:object'], 'as:summary', '@value') ?? '';
1651                 $content .= ' ' . HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1652
1653                 $attachments = JsonLD::fetchElementArray($activity['as:object'], 'as:attachment') ?? [];
1654                 foreach ($attachments as $media) {
1655                         if (!empty($media['as:summary'])) {
1656                                 $content .= ' ' . JsonLD::fetchElement($media, 'as:summary', '@value');
1657                         }
1658                         if (!empty($media['as:name'])) {
1659                                 $content .= ' ' . JsonLD::fetchElement($media, 'as:name', '@value');
1660                         }
1661                 }
1662
1663                 $messageTags = [];
1664                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1665                 if (!empty($tags)) {
1666                         foreach ($tags as $tag) {
1667                                 if (($tag['type'] != 'Hashtag') && !strpos($tag['type'], ':Hashtag')) {
1668                                         continue;
1669                                 }
1670                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1671                         }
1672                 }
1673
1674                 return Relay::isSolicitedPost($messageTags, $content, $authorid, $id, Protocol::ACTIVITYPUB, $activity['thread-completion'] ?? 0);
1675         }
1676
1677         /**
1678          * perform a "follow" request
1679          *
1680          * @param array $activity
1681          * @return void
1682          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1683          * @throws \ImagickException
1684          */
1685         public static function followUser(array $activity)
1686         {
1687                 $uid = User::getIdForURL($activity['object_id']);
1688                 if (empty($uid)) {
1689                         Queue::remove($activity);
1690                         return;
1691                 }
1692
1693                 $owner = User::getOwnerDataById($uid);
1694                 if (empty($owner)) {
1695                         return;
1696                 }
1697
1698                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1699                 if (!empty($cid)) {
1700                         self::switchContact($cid);
1701                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1702                 }
1703
1704                 $item = [
1705                         'author-id' => Contact::getIdForURL($activity['actor']),
1706                         'author-link' => $activity['actor'],
1707                 ];
1708
1709                 // Ensure that the contact has got the right network type
1710                 self::switchContact($item['author-id']);
1711
1712                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1713                 if ($result === true) {
1714                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1715                 }
1716
1717                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1718                 if (empty($cid)) {
1719                         return;
1720                 }
1721
1722                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1723                         self::transmitPendingEvents($cid, $owner['uid']);
1724                 }
1725
1726                 if (empty($contact)) {
1727                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1728                 }
1729                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1730                 Queue::remove($activity);
1731         }
1732
1733         /**
1734          * Transmit pending events to the new follower
1735          *
1736          * @param integer $cid Contact id
1737          * @param integer $uid User id
1738          * @return void
1739          */
1740         private static function transmitPendingEvents(int $cid, int $uid)
1741         {
1742                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1743                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1744
1745                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1746                 while ($event = DBA::fetch($events)) {
1747                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1748                         if (empty($post)) {
1749                                 continue;
1750                         }
1751                         if (DI::config()->get('system', 'bulk_delivery')) {
1752                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1753                                 Worker::add(Worker::PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1754                         } else {
1755                                 Worker::add(Worker::PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1756                         }
1757                 }
1758         }
1759
1760         /**
1761          * Update the given profile
1762          *
1763          * @param array $activity
1764          * @throws \Exception
1765          */
1766         public static function updatePerson(array $activity)
1767         {
1768                 if (empty($activity['object_id'])) {
1769                         return;
1770                 }
1771
1772                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1773                 Contact::updateFromProbeByURL($activity['object_id']);
1774                 Queue::remove($activity);
1775         }
1776
1777         /**
1778          * Delete the given profile
1779          *
1780          * @param array $activity
1781          * @return void
1782          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1783          */
1784         public static function deletePerson(array $activity)
1785         {
1786                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1787                         Logger::info('Empty object id or actor.');
1788                         Queue::remove($activity);
1789                         return;
1790                 }
1791
1792                 if ($activity['object_id'] != $activity['actor']) {
1793                         Logger::info('Object id does not match actor.');
1794                         Queue::remove($activity);
1795                         return;
1796                 }
1797
1798                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1799                 while ($contact = DBA::fetch($contacts)) {
1800                         Contact::remove($contact['id']);
1801                 }
1802                 DBA::close($contacts);
1803
1804                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1805                 Queue::remove($activity);
1806         }
1807
1808         /**
1809          * Add moved contacts as followers for all subscribers of the old contact
1810          *
1811          * @param array $activity
1812          * @return void
1813          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1814          */
1815         public static function movePerson(array $activity)
1816         {
1817                 if (empty($activity['target_id']) || empty($activity['object_id'])) {
1818                         Queue::remove($activity);
1819                         return;
1820                 }
1821
1822                 if ($activity['object_id'] != $activity['actor']) {
1823                         Logger::notice('Object is not the actor', ['activity' => $activity]);
1824                         Queue::remove($activity);
1825                         return;
1826                 }
1827
1828                 $from = Contact::getByURL($activity['object_id'], false, ['uri-id']);
1829                 if (empty($from['uri-id'])) {
1830                         Logger::info('Object not found', ['activity' => $activity]);
1831                         Queue::remove($activity);
1832                         return;
1833                 }
1834
1835                 $contacts = DBA::select('contact', ['uid', 'url'], ["`uri-id` = ? AND `uid` != ? AND `rel` IN (?, ?)", $from['uri-id'], 0, Contact::FRIEND, Contact::SHARING]);
1836                 while ($from_contact = DBA::fetch($contacts)) {
1837                         $result = Contact::createFromProbeForUser($from_contact['uid'], $activity['target_id']);
1838                         Logger::debug('Follower added', ['from' => $from_contact, 'result' => $result]);
1839                 }
1840                 DBA::close($contacts);
1841                 Queue::remove($activity);
1842         }
1843
1844         /**
1845          * Blocks the user by the contact
1846          *
1847          * @param array $activity
1848          * @return void
1849          * @throws \Exception
1850          */
1851         public static function blockAccount(array $activity)
1852         {
1853                 $cid = Contact::getIdForURL($activity['actor']);
1854                 if (empty($cid)) {
1855                         return;
1856                 }
1857
1858                 $uid = User::getIdForURL($activity['object_id']);
1859                 if (empty($uid)) {
1860                         return;
1861                 }
1862
1863                 Contact\User::setIsBlocked($cid, $uid, true);
1864
1865                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1866                 Queue::remove($activity);
1867         }
1868
1869         /**
1870          * Unblocks the user by the contact
1871          *
1872          * @param array $activity
1873          * @return void
1874          * @throws \Exception
1875          */
1876         public static function unblockAccount(array $activity)
1877         {
1878                 $cid = Contact::getIdForURL($activity['actor']);
1879                 if (empty($cid)) {
1880                         return;
1881                 }
1882
1883                 $uid = User::getIdForURL($activity['object_object']);
1884                 if (empty($uid)) {
1885                         return;
1886                 }
1887
1888                 Contact\User::setIsBlocked($cid, $uid, false);
1889
1890                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1891                 Queue::remove($activity);
1892         }
1893
1894         /**
1895          * Report a user
1896          *
1897          * @param array $activity
1898          * @return void
1899          * @throws \Exception
1900          */
1901         public static function ReportAccount(array $activity)
1902         {
1903                 $account = Contact::getByURL($activity['object_id'], null, ['id', 'gsid']);
1904                 if (empty($account)) {
1905                         Logger::info('Unknown account', ['activity' => $activity]);
1906                         Queue::remove($activity);
1907                         return;
1908                 }
1909
1910                 $reporter_id = Contact::getIdForURL($activity['actor']);
1911                 if (empty($reporter_id)) {
1912                         Logger::info('Unknown actor', ['activity' => $activity]);
1913                         Queue::remove($activity);
1914                         return;
1915                 }
1916
1917                 $uri_ids = [];
1918                 foreach ($activity['object_ids'] as $status_id) {
1919                         $post = Post::selectFirst(['uri-id'], ['uri' => $status_id]);
1920                         if (!empty($post['uri-id'])) {
1921                                 $uri_ids[] = $post['uri-id'];
1922                         }
1923                 }
1924
1925                 $report = DI::reportFactory()->createFromReportsRequest(System::getRules(true), $reporter_id, $account['id'], $account['gsid'], $activity['content'], 'other', false, $uri_ids);
1926                 DI::report()->save($report);
1927
1928                 Logger::info('Stored report', ['reporter' => $reporter_id, 'account' => $account, 'comment' => $activity['content'], 'object_ids' => $activity['object_ids']]);
1929         }
1930
1931         /**
1932          * Accept a follow request
1933          *
1934          * @param array $activity
1935          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1936          * @throws \ImagickException
1937          */
1938         public static function acceptFollowUser(array $activity)
1939         {
1940                 if (!empty($activity['object_actor'])) {
1941                         $uid      = User::getIdForURL($activity['object_actor']);
1942                         $check_id = false;
1943                 } elseif (!empty($activity['receiver']) && (count($activity['receiver']) == 1)) {
1944                         $uid      = array_shift($activity['receiver']);
1945                         $check_id = true;
1946                 }
1947
1948                 if (empty($uid)) {
1949                         Logger::notice('User could not be detected', ['activity' => $activity]);
1950                         Queue::remove($activity);
1951                         return;
1952                 }
1953
1954                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1955                 if (empty($cid)) {
1956                         Logger::notice('No contact found', ['actor' => $activity['actor']]);
1957                         Queue::remove($activity);
1958                         return;
1959                 }
1960
1961                 $id = Transmitter::activityIDFromContact($cid);
1962                 if ($id == $activity['object_id']) {
1963                         Logger::info('Successful id check', ['uid' => $uid, 'cid' => $cid]);
1964                 } else {
1965                         Logger::info('Unsuccessful id check', ['uid' => $uid, 'cid' => $cid, 'id' => $id, 'object_id' => $activity['object_id']]);
1966                         if ($check_id) {
1967                                 Queue::remove($activity);
1968                                 return;
1969                         }
1970                 }
1971
1972                 self::switchContact($cid);
1973
1974                 $fields = ['pending' => false];
1975
1976                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1977                 if ($contact['rel'] == Contact::FOLLOWER) {
1978                         $fields['rel'] = Contact::FRIEND;
1979                 }
1980
1981                 $condition = ['id' => $cid];
1982                 Contact::update($fields, $condition);
1983                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1984                 Queue::remove($activity);
1985         }
1986
1987         /**
1988          * Reject a follow request
1989          *
1990          * @param array $activity
1991          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1992          * @throws \ImagickException
1993          */
1994         public static function rejectFollowUser(array $activity)
1995         {
1996                 $uid = User::getIdForURL($activity['object_actor']);
1997                 if (empty($uid)) {
1998                         return;
1999                 }
2000
2001                 $cid = Contact::getIdForURL($activity['actor'], $uid);
2002                 if (empty($cid)) {
2003                         Logger::info('No contact found', ['actor' => $activity['actor']]);
2004                         return;
2005                 }
2006
2007                 self::switchContact($cid);
2008
2009                 $contact = Contact::getById($cid, ['rel']);
2010                 if ($contact['rel'] == Contact::SHARING) {
2011                         Contact::remove($cid);
2012                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
2013                 } elseif ($contact['rel'] == Contact::FRIEND) {
2014                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
2015                 } else {
2016                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
2017                 }
2018                 Queue::remove($activity);
2019         }
2020
2021         /**
2022          * Undo activity like "like" or "dislike"
2023          *
2024          * @param array $activity
2025          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2026          * @throws \ImagickException
2027          */
2028         public static function undoActivity(array $activity)
2029         {
2030                 if (empty($activity['object_id'])) {
2031                         return;
2032                 }
2033
2034                 if (empty($activity['object_actor'])) {
2035                         return;
2036                 }
2037
2038                 $author_id = Contact::getIdForURL($activity['object_actor']);
2039                 if (empty($author_id)) {
2040                         return;
2041                 }
2042
2043                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => Item::GRAVITY_ACTIVITY]);
2044                 Queue::remove($activity);
2045         }
2046
2047         /**
2048          * Activity to remove a follower
2049          *
2050          * @param array $activity
2051          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2052          * @throws \ImagickException
2053          */
2054         public static function undoFollowUser(array $activity)
2055         {
2056                 $uid = User::getIdForURL($activity['object_object']);
2057                 if (empty($uid)) {
2058                         return;
2059                 }
2060
2061                 $owner = User::getOwnerDataById($uid);
2062                 if (empty($owner)) {
2063                         return;
2064                 }
2065
2066                 $cid = Contact::getIdForURL($activity['actor'], $uid);
2067                 if (empty($cid)) {
2068                         Logger::info('No contact found', ['actor' => $activity['actor']]);
2069                         return;
2070                 }
2071
2072                 self::switchContact($cid);
2073
2074                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
2075                 if (!DBA::isResult($contact)) {
2076                         return;
2077                 }
2078
2079                 Contact::removeFollower($contact);
2080                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
2081                 Queue::remove($activity);
2082         }
2083
2084         /**
2085          * Switches a contact to AP if needed
2086          *
2087          * @param integer $cid Contact ID
2088          * @return void
2089          * @throws \Exception
2090          */
2091         private static function switchContact(int $cid)
2092         {
2093                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
2094                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
2095                         return;
2096                 }
2097
2098                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
2099                 Contact::updateFromProbe($cid);
2100         }
2101
2102         /**
2103          * Collects implicit mentions like:
2104          * - the author of the parent item
2105          * - all the mentioned conversants in the parent item
2106          *
2107          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
2108          * @return array
2109          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2110          */
2111         private static function getImplicitMentionList(array $parent): array
2112         {
2113                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
2114
2115                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
2116
2117                 $implicit_mentions = [];
2118                 if (empty($parent_author['url'])) {
2119                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
2120                 } else {
2121                         $implicit_mentions[] = $parent_author['url'];
2122                         $implicit_mentions[] = $parent_author['nurl'];
2123                         $implicit_mentions[] = $parent_author['alias'];
2124                 }
2125
2126                 if (!empty($parent['alias'])) {
2127                         $implicit_mentions[] = $parent['alias'];
2128                 }
2129
2130                 foreach ($parent_terms as $term) {
2131                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
2132                         if (!empty($contact['url'])) {
2133                                 $implicit_mentions[] = $contact['url'];
2134                                 $implicit_mentions[] = $contact['nurl'];
2135                                 $implicit_mentions[] = $contact['alias'];
2136                         }
2137                 }
2138
2139                 return $implicit_mentions;
2140         }
2141
2142         /**
2143          * Strips from the body prepended implicit mentions
2144          *
2145          * @param string $body
2146          * @param array $parent
2147          * @return string
2148          */
2149         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
2150         {
2151                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
2152                         return $body;
2153                 }
2154
2155                 $potential_mentions = self::getImplicitMentionList($parent);
2156
2157                 $kept_mentions = [];
2158
2159                 // Extract one prepended mention at a time from the body
2160                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
2161                         if (!in_array($matches[2], $potential_mentions)) {
2162                                 $kept_mentions[] = $matches[1];
2163                         }
2164
2165                         $body = $matches[3];
2166                 }
2167
2168                 // Re-appending the kept mentions to the body after extraction
2169                 $kept_mentions[] = $body;
2170
2171                 return implode('', $kept_mentions);
2172         }
2173
2174         /**
2175          * Adds links to string mentions
2176          *
2177          * @param string $body
2178          * @param array  $tags
2179          * @return string
2180          */
2181         protected static function addMentionLinks(string $body, array $tags): string
2182         {
2183                 // This prevents links to be added again to Pleroma-style mention links
2184                 $body = self::normalizeMentionLinks($body);
2185
2186                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
2187                         foreach ($tags as $tag) {
2188                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
2189                                         continue;
2190                                 }
2191
2192                                 $hash = substr($tag['name'], 0, 1);
2193                                 $name = substr($tag['name'], 1);
2194                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
2195                                         $hash = '';
2196                                         $name = $tag['name'];
2197                                 }
2198
2199                                 if (Network::isValidHttpUrl($tag['href'])) {
2200                                         $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
2201                                 }
2202                         }
2203
2204                         return $body;
2205                 });
2206
2207                 return $body;
2208         }
2209 }