src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2023, the Friendica project
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol\ActivityPub;
  23
  24 use Friendica\Content\Text\BBCode;
  25 use Friendica\Content\Text\HTML;
  26 use Friendica\Content\Text\Markdown;
  27 use Friendica\Core\Cache\Enum\Duration;
  28 use Friendica\Core\Logger;
  29 use Friendica\Core\Protocol;
  30 use Friendica\Core\System;
  31 use Friendica\Core\Worker;
  32 use Friendica\Database\DBA;
  33 use Friendica\DI;
  34 use Friendica\Model\APContact;
  35 use Friendica\Model\Contact;
  36 use Friendica\Model\Conversation;
  37 use Friendica\Model\Event;
  38 use Friendica\Model\GServer;
  39 use Friendica\Model\Item;
  40 use Friendica\Model\ItemURI;
  41 use Friendica\Model\Mail;
  42 use Friendica\Model\Tag;
  43 use Friendica\Model\User;
  44 use Friendica\Model\Post;
  45 use Friendica\Protocol\Activity;
  46 use Friendica\Protocol\ActivityPub;
  47 use Friendica\Protocol\Delivery;
  48 use Friendica\Protocol\Relay;
  49 use Friendica\Util\DateTimeFormat;
  50 use Friendica\Util\HTTPSignature;
  51 use Friendica\Util\JsonLD;
  52 use Friendica\Util\Network;
  53 use Friendica\Util\Strings;
  54
  55 /**
  56  * ActivityPub Processor Protocol class
  57  */
  58 class Processor
  59 {
  60         const CACHEKEY_FETCH_ACTIVITY = 'processor:fetchMissingActivity:';
  61         const CACHEKEY_JUST_FETCHED   = 'processor:isJustFetched:';
  62
  63         /**
  64          * Add an object id to the list of processed ids
  65          *
  66          * @param string $id
  67          *
  68          * @return void
  69          */
  70         private static function addActivityId(string $id)
  71         {
  72                 DBA::delete('fetched-activity', ["`received` < ?", DateTimeFormat::utc('now - 5 minutes')]);
  73                 DBA::insert('fetched-activity', ['object-id' => $id, 'received' => DateTimeFormat::utcNow()]);
  74         }
  75
  76         /**
  77          * Checks if the given object id has just been fetched
  78          *
  79          * @param string $id
  80          *
  81          * @return boolean
  82          */
  83         private static function isFetched(string $id): bool
  84         {
  85                 return DBA::exists('fetched-activity', ['object-id' => $id]);
  86         }
  87
  88         /**
  89          * Extracts the tag character (#, @, !) from mention links
  90          *
  91          * @param string $body
  92          * @return string
  93          */
  94         public static function normalizeMentionLinks(string $body): string
  95         {
  96                 $body = preg_replace('%\[url=([^\[\]]*)]([#@!])(.*?)\[/url]%ism', '$2[url=$1]$3[/url]', $body);
  97                 $body = preg_replace('%([#@!])\[zrl=([^\[\]]*)](.*?)\[/zrl]%ism', '$1[url=$2]$3[/url]', $body);
  98                 return $body;
  99         }
 100
 101         /**
 102          * Convert the language array into a language JSON
 103          *
 104          * @param array $languages
 105          * @return string language JSON
 106          */
 107         private static function processLanguages(array $languages): string
 108         {
 109                 $codes = array_keys($languages);
 110                 $lang = [];
 111                 foreach ($codes as $code) {
 112                         $lang[$code] = 1;
 113                 }
 114
 115                 if (empty($lang)) {
 116                         return '';
 117                 }
 118
 119                 return json_encode($lang);
 120         }
 121         /**
 122          * Replaces emojis in the body
 123          *
 124          * @param int $uri_id
 125          * @param string $body
 126          * @param array $emojis
 127          *
 128          * @return string with replaced emojis
 129          */
 130         private static function replaceEmojis(int $uri_id, string $body, array $emojis): string
 131         {
 132                 $body = strtr($body,
 133                         array_combine(
 134                                 array_column($emojis, 'name'),
 135                                 array_map(function ($emoji) {
 136                                         return '[emoji=' . $emoji['href'] . ']' . $emoji['name'] . '[/emoji]';
 137                                 }, $emojis)
 138                         )
 139                 );
 140
 141                 // We store the emoji here to be able to avoid storing it in the media
 142                 foreach ($emojis as $emoji) {
 143                         Post\Link::getByLink($uri_id, $emoji['href']);
 144                 }
 145                 return $body;
 146         }
 147
 148         /**
 149          * Store attached media files in the post-media table
 150          *
 151          * @param int $uriid
 152          * @param array $attachment
 153          * @return void
 154          */
 155         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
 156         {
 157                 if (empty($attachment['url'])) {
 158                         return;
 159                 }
 160
 161                 $data = ['uri-id' => $uriid];
 162                 $data['type'] = Post\Media::UNKNOWN;
 163                 $data['url'] = $attachment['url'];
 164                 $data['mimetype'] = $attachment['mediaType'] ?? null;
 165                 $data['height'] = $attachment['height'] ?? null;
 166                 $data['width'] = $attachment['width'] ?? null;
 167                 $data['size'] = $attachment['size'] ?? null;
 168                 $data['preview'] = $attachment['image'] ?? null;
 169                 $data['description'] = $attachment['name'] ?? null;
 170
 171                 Post\Media::insert($data);
 172         }
 173
 174         /**
 175          * Store attachment data
 176          *
 177          * @param array   $activity
 178          * @param array   $item
 179          */
 180         private static function storeAttachments(array $activity, array $item)
 181         {
 182                 if (empty($activity['attachments'])) {
 183                         return;
 184                 }
 185
 186                 foreach ($activity['attachments'] as $attach) {
 187                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 188                 }
 189         }
 190
 191         /**
 192          * Store question data
 193          *
 194          * @param array   $activity
 195          * @param array   $item
 196          */
 197         private static function storeQuestion(array $activity, array $item)
 198         {
 199                 if (empty($activity['question'])) {
 200                         return;
 201                 }
 202                 $question = ['multiple' => $activity['question']['multiple']];
 203
 204                 if (!empty($activity['question']['voters'])) {
 205                         $question['voters'] = $activity['question']['voters'];
 206                 }
 207
 208                 if (!empty($activity['question']['end-time'])) {
 209                         $question['end-time'] = DateTimeFormat::utc($activity['question']['end-time']);
 210                 }
 211
 212                 Post\Question::update($item['uri-id'], $question);
 213
 214                 foreach ($activity['question']['options'] as $key => $option) {
 215                         $option = ['name' => $option['name'], 'replies' => $option['replies']];
 216                         Post\QuestionOption::update($item['uri-id'], $key, $option);
 217                 }
 218
 219                 Logger::debug('Storing incoming question', ['type' => $activity['type'], 'uri-id' => $item['uri-id'], 'question' => $activity['question']]);
 220         }
 221
 222         /**
 223          * Updates a message
 224          *
 225          * @param array      $activity   Activity array
 226          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 227          * @throws \ImagickException
 228          */
 229         public static function updateItem(array $activity)
 230         {
 231                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type', 'private'], ['uri' => $activity['id']]);
 232                 if (!DBA::isResult($item)) {
 233                         Logger::notice('No existing item, item will be created', ['uri' => $activity['id']]);
 234                         $item = self::createItem($activity, false);
 235                         if (empty($item)) {
 236                                 Queue::remove($activity);
 237                                 return;
 238                         }
 239
 240                         self::postItem($activity, $item);
 241                         return;
 242                 }
 243
 244                 $item['changed'] = DateTimeFormat::utcNow();
 245                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 246
 247                 Post\Media::deleteByURIId($item['uri-id'], [Post\Media::AUDIO, Post\Media::VIDEO, Post\Media::IMAGE, Post\Media::HTML]);
 248                 $item = self::processContent($activity, $item);
 249                 if (empty($item)) {
 250                         Queue::remove($activity);
 251                         return;
 252                 }
 253
 254                 self::storeAttachments($activity, $item);
 255                 self::storeQuestion($activity, $item);
 256
 257                 Post\History::add($item['uri-id'], $item);
 258                 Item::update($item, ['uri' => $activity['id']]);
 259
 260                 Queue::remove($activity);
 261
 262                 if ($activity['object_type'] == 'as:Event') {
 263                         $posts = Post::select(['event-id', 'uid'], ["`uri` = ? AND `event-id` > ?", $activity['id'], 0]);
 264                         while ($post = DBA::fetch($posts)) {
 265                                 self::updateEvent($post['event-id'], $activity);
 266                         }
 267                 }
 268         }
 269
 270         /**
 271          * Update an existing event
 272          *
 273          * @param int $event_id
 274          * @param array $activity
 275          */
 276         private static function updateEvent(int $event_id, array $activity)
 277         {
 278                 $event = DBA::selectFirst('event', [], ['id' => $event_id]);
 279
 280                 $event['edited']   = DateTimeFormat::utc($activity['updated']);
 281                 $event['summary']  = HTML::toBBCode($activity['name']);
 282                 $event['desc']     = HTML::toBBCode($activity['content']);
 283                 if (!empty($activity['start-time'])) {
 284                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 285                 }
 286                 if (!empty($activity['end-time'])) {
 287                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 288                 }
 289                 $event['nofinish'] = empty($event['finish']);
 290                 $event['location'] = $activity['location'];
 291
 292                 Logger::info('Updating event', ['uri' => $activity['id'], 'id' => $event_id]);
 293                 Event::store($event);
 294         }
 295
 296         /**
 297          * Prepares data for a message
 298          *
 299          * @param array $activity      Activity array
 300          * @param bool  $fetch_parents
 301          *
 302          * @return array Internal item
 303          *
 304          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 305          * @throws \ImagickException
 306          */
 307         public static function createItem(array $activity, bool $fetch_parents): array
 308         {
 309                 $item = [];
 310                 $item['verb'] = Activity::POST;
 311                 $item['thr-parent'] = $activity['reply-to-id'];
 312
 313                 if ($activity['reply-to-id'] == $activity['id']) {
 314                         $item['gravity'] = Item::GRAVITY_PARENT;
 315                         $item['object-type'] = Activity\ObjectType::NOTE;
 316                 } else {
 317                         $item['gravity'] = Item::GRAVITY_COMMENT;
 318                         $item['object-type'] = Activity\ObjectType::COMMENT;
 319                 }
 320
 321                 if (!empty($activity['conversation'])) {
 322                         $item['conversation'] = $activity['conversation'];
 323                 } elseif (!empty($activity['context'])) {
 324                         $item['conversation'] = $activity['context'];
 325                 }
 326
 327                 if (!empty($item['conversation'])) {
 328                         $conversation = Post::selectFirstThread(['uri'], ['conversation' => $item['conversation']]);
 329                         if (!empty($conversation)) {
 330                                 Logger::debug('Got conversation', ['conversation' => $item['conversation'], 'parent' => $conversation]);
 331                                 $item['parent-uri'] = $conversation['uri'];
 332                                 $item['parent-uri-id'] = ItemURI::getIdByURI($item['parent-uri']);
 333                         }
 334                 } else {
 335                         $conversation = [];
 336                 }
 337
 338                 Logger::debug('Create Item', ['id' => $activity['id'], 'conversation' => $item['conversation'] ?? '']);
 339                 if (empty($activity['author']) && empty($activity['actor'])) {
 340                         Logger::notice('Missing author and actor. We quit here.', ['activity' => $activity]);
 341                         Queue::remove($activity);
 342                         return [];
 343                 }
 344
 345                 if (!in_array(0, $activity['receiver']) || !DI::config()->get('system', 'fetch_parents')) {
 346                         $fetch_parents = false;
 347                 }
 348
 349                 if ($fetch_parents && empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 350                         $result = self::fetchParent($activity, !empty($conversation));
 351                         if (!empty($result)) {
 352                                 if (($item['thr-parent'] != $result) && Post::exists(['uri' => $result])) {
 353                                         $item['thr-parent'] = $result;
 354                                 }
 355                         } elseif (empty($conversation)) {
 356                                 return [];
 357                         }
 358                 }
 359
 360                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 361
 362                 if (empty($conversation) && empty($activity['directmessage']) && ($item['gravity'] != Item::GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 363                         Logger::notice('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 364                         if (!$fetch_parents) {
 365                                 Queue::remove($activity);
 366                         }
 367                         return [];
 368                 }
 369
 370                 $item['network'] = Protocol::ACTIVITYPUB;
 371                 $item['author-link'] = $activity['author'];
 372                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 373                 $item['owner-link'] = $activity['actor'];
 374                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 375
 376                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 377                         $item['private'] = Item::UNLISTED;
 378                 } elseif (in_array(0, $activity['receiver'])) {
 379                         $item['private'] = Item::PUBLIC;
 380                 } else {
 381                         $item['private'] = Item::PRIVATE;
 382                 }
 383
 384                 if (!empty($activity['raw'])) {
 385                         $item['source'] = $activity['raw'];
 386                 }
 387
 388                 $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 389
 390                 if (isset($activity['push'])) {
 391                         $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 392                 }
 393
 394                 if (!empty($activity['from-relay'])) {
 395                         $item['direction'] = Conversation::RELAY;
 396                 }
 397
 398                 if ($activity['object_type'] == 'as:Article') {
 399                         $item['post-type'] = Item::PT_ARTICLE;
 400                 } elseif ($activity['object_type'] == 'as:Audio') {
 401                         $item['post-type'] = Item::PT_AUDIO;
 402                 } elseif ($activity['object_type'] == 'as:Document') {
 403                         $item['post-type'] = Item::PT_DOCUMENT;
 404                 } elseif ($activity['object_type'] == 'as:Event') {
 405                         $item['post-type'] = Item::PT_EVENT;
 406                 } elseif ($activity['object_type'] == 'as:Image') {
 407                         $item['post-type'] = Item::PT_IMAGE;
 408                 } elseif ($activity['object_type'] == 'as:Page') {
 409                         $item['post-type'] = Item::PT_PAGE;
 410                 } elseif ($activity['object_type'] == 'as:Question') {
 411                         $item['post-type'] = Item::PT_POLL;
 412                 } elseif ($activity['object_type'] == 'as:Video') {
 413                         $item['post-type'] = Item::PT_VIDEO;
 414                 } else {
 415                         $item['post-type'] = Item::PT_NOTE;
 416                 }
 417
 418                 $item['isGroup'] = false;
 419
 420                 if (!empty($activity['thread-completion'])) {
 421                         if ($activity['thread-completion'] != $item['owner-id']) {
 422                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 423                                 $item['causer-link'] = $actor['url'];
 424                                 $item['causer-id']   = $activity['thread-completion'];
 425                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 426                         } else {
 427                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 428                                 $item['causer-link'] = $item['owner-link'];
 429                                 $item['causer-id']   = $item['owner-id'];
 430                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 431                         }
 432
 433                         $item['owner-link'] = $item['author-link'];
 434                         $item['owner-id']   = $item['author-id'];
 435                 }
 436
 437                 if (!$item['isGroup'] && !empty($activity['receiver_urls']['as:audience'])) {
 438                         foreach ($activity['receiver_urls']['as:audience'] as $audience) {
 439                                 $actor = APContact::getByURL($audience, false);
 440                                 if (($actor['type'] ?? 'Person') == 'Group') {
 441                                         Logger::debug('Group post detected via audience.', ['audience' => $audience, 'actor' => $activity['actor'], 'author' => $activity['author']]);
 442                                         $item['isGroup']    = true;
 443                                         $item['group-link'] = $item['owner-link'] = $audience;
 444                                         $item['owner-id']   = Contact::getIdForURL($audience);
 445                                         break;
 446                                 }
 447                         }
 448                 } else {
 449                         $owner = APContact::getByURL($item['owner-link'], false);
 450                 }
 451
 452                 if (!$item['isGroup'] && (($owner['type'] ?? 'Person') == 'Group')) {
 453                         Logger::debug('Group post detected via owner.', ['actor' => $activity['actor'], 'author' => $activity['author']]);
 454                         $item['isGroup']    = true;
 455                         $item['group-link'] = $item['owner-link'];
 456                 } elseif (!empty($item['causer-link'])) {
 457                         $causer = APContact::getByURL($item['causer-link'], false);
 458                 }
 459
 460                 if (!$item['isGroup'] && (($causer['type'] ?? 'Person') == 'Group')) {
 461                         Logger::debug('Group post detected via causer.', ['actor' => $activity['actor'], 'author' => $activity['author'], 'causer' => $item['causer-link']]);
 462                         $item['isGroup']    = true;
 463                         $item['group-link'] = $item['causer-link'];
 464                 }
 465
 466                 if (!empty($item['group-link']) && empty($item['causer-link'])) {
 467                         $item['causer-link'] = $item['group-link'];
 468                         $item['causer-id']   = Contact::getIdForURL($item['causer-link']);
 469                 }
 470
 471                 $item['uri'] = $activity['id'];
 472
 473                 if (empty($activity['published']) || empty($activity['updated'])) {
 474                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 475                 }
 476
 477                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 478                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 479                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 480                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 481
 482                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 483                 if (empty($item['uri-id'])) {
 484                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 485                         return [];
 486                 }
 487
 488                 $item['thr-parent-id'] = ItemURI::getIdByURI($item['thr-parent']);
 489
 490                 $item = self::processContent($activity, $item);
 491                 if (empty($item)) {
 492                         Logger::info('Message was not processed');
 493                         Queue::remove($activity);
 494                         return [];
 495                 }
 496
 497                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 498
 499                 self::storeAttachments($activity, $item);
 500                 self::storeQuestion($activity, $item);
 501
 502                 // We received the post via AP, so we set the protocol of the server to AP
 503                 $contact = Contact::getById($item['author-id'], ['gsid']);
 504                 if (!empty($contact['gsid'])) {
 505                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 506                 }
 507
 508                 if ($item['author-id'] != $item['owner-id']) {
 509                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 510                         if (!empty($contact['gsid'])) {
 511                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 512                         }
 513                 }
 514
 515                 return $item;
 516         }
 517
 518         /**
 519          * Fetch and process parent posts for the given activity
 520          *
 521          * @param array $activity
 522          * @param bool  $in_background
 523          *
 524          * @return string
 525          */
 526         private static function fetchParent(array $activity, bool $in_background = false): string
 527         {
 528                 if (self::isFetched($activity['reply-to-id'])) {
 529                         Logger::info('Id is already fetched', ['id' => $activity['reply-to-id']]);
 530                         return '';
 531                 }
 532
 533                 self::addActivityId($activity['reply-to-id']);
 534
 535                 if (!DI::config()->get('system', 'fetch_by_worker')) {
 536                         $in_background = false;
 537                 }
 538
 539                 $recursion_depth = $activity['recursion-depth'] ?? 0;
 540
 541                 if (!$in_background && ($recursion_depth < DI::config()->get('system', 'max_recursion_depth'))) {
 542                         Logger::info('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 543                         $result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 544                         if (empty($result) && self::isActivityGone($activity['reply-to-id'])) {
 545                                 Logger::notice('The activity is gone, the queue entry will be deleted', ['parent' => $activity['reply-to-id']]);
 546                                 if (!empty($activity['entry-id'])) {
 547                                         Queue::deleteById($activity['entry-id']);
 548                                 }
 549                                 return '';
 550                         } elseif (!empty($result)) {
 551                                 $exists = Post::exists(['uri' => [$result, $activity['reply-to-id']]]);
 552                                 if ($exists) {
 553                                         Logger::info('The activity has been fetched and created.', ['parent' => $result]);
 554                                         return $result;
 555                                 } elseif (DI::config()->get('system', 'fetch_by_worker') || DI::config()->get('system', 'decoupled_receiver')) {
 556                                         Logger::info('The activity has been fetched and will hopefully be created later.', ['parent' => $result]);
 557                                 } else {
 558                                         Logger::notice('The activity exists but has not been created, the queue entry will be deleted.', ['parent' => $result]);
 559                                         if (!empty($activity['entry-id'])) {
 560                                                 Queue::deleteById($activity['entry-id']);
 561                                         }
 562                                 }
 563                                 return '';
 564                         }
 565                         if (empty($result) && !DI::config()->get('system', 'fetch_by_worker')) {
 566                                 return '';
 567                         }
 568                 } elseif (self::isActivityGone($activity['reply-to-id'])) {
 569                         Logger::notice('The activity is gone. We will not spawn a worker. The queue entry will be deleted', ['parent' => $activity['reply-to-id']]);
 570                         if ($in_background) {
 571                                 // fetching in background is done for all activities where we have got the conversation
 572                                 // There we only delete the single activity and not the whole thread since we can store the
 573                                 // other posts in the thread even with missing posts.
 574                                 Queue::remove($activity);
 575                         } elseif (!empty($activity['entry-id'])) {
 576                                 Queue::deleteById($activity['entry-id']);
 577                         }
 578                         return '';
 579                 } elseif ($in_background) {
 580                         Logger::notice('Fetching is done in the background.', ['parent' => $activity['reply-to-id']]);
 581                 } else {
 582                         Logger::notice('Recursion level is too high.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 583                 }
 584
 585                 if (!Fetch::hasWorker($activity['reply-to-id'])) {
 586                         Logger::notice('Fetching is done by worker.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 587                         Fetch::add($activity['reply-to-id']);
 588                         $activity['recursion-depth'] = 0;
 589                         $wid = Worker::add(Worker::PRIORITY_HIGH, 'FetchMissingActivity', $activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 590                         Fetch::setWorkerId($activity['reply-to-id'], $wid);
 591                 } else {
 592                         Logger::debug('Activity will already be fetched via a worker.', ['url' => $activity['reply-to-id']]);
 593                 }
 594
 595                 return '';
 596         }
 597
 598         /**
 599          * Check if a given activity is no longer available
 600          *
 601          * @param string $url
 602          *
 603          * @return boolean
 604          */
 605         public static function isActivityGone(string $url): bool
 606         {
 607                 try {
 608                         $curlResult = HTTPSignature::fetchRaw($url, 0);
 609                 } catch (\Exception $exception) {
 610                         Logger::notice('Error fetching url', ['url' => $url, 'exception' => $exception]);
 611                         return true;
 612                 }
 613
 614                 if (Network::isUrlBlocked($url)) {
 615                         return true;
 616                 }
 617
 618                 // @todo To ensure that the remote system is working correctly, we can check if the "Content-Type" contains JSON
 619                 if (in_array($curlResult->getReturnCode(), [401, 404])) {
 620                         return true;
 621                 }
 622
 623                 if ($curlResult->isSuccess()) {
 624                         $object = json_decode($curlResult->getBody(), true);
 625                         if (!empty($object)) {
 626                                 $activity = JsonLD::compact($object);
 627                                 if (JsonLD::fetchElement($activity, '@type') == 'as:Tombstone') {
 628                                         return true;
 629                                 }
 630                         }
 631                 } elseif ($curlResult->getReturnCode() == 0) {
 632                         $host = parse_url($url, PHP_URL_HOST);
 633                         if (!(filter_var($host, FILTER_VALIDATE_IP) || @dns_get_record($host . '.', DNS_A + DNS_AAAA))) {
 634                                 return true;
 635                         }
 636                 }
 637
 638                 return false;
 639         }
 640         /**
 641          * Delete items
 642          *
 643          * @param array $activity
 644          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 645          * @throws \ImagickException
 646          */
 647         public static function deleteItem(array $activity)
 648         {
 649                 $owner = Contact::getIdForURL($activity['actor']);
 650
 651                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 652                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 653                 Queue::remove($activity);
 654         }
 655
 656         /**
 657          * Prepare the item array for an activity
 658          *
 659          * @param array $activity Activity array
 660          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 661          * @throws \ImagickException
 662          */
 663         public static function addTag(array $activity)
 664         {
 665                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 666                         return;
 667                 }
 668
 669                 foreach ($activity['receiver'] as $receiver) {
 670                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 671                         if (!DBA::isResult($item)) {
 672                                 // We don't fetch missing content for this purpose
 673                                 continue;
 674                         }
 675
 676                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 677                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 678                                 continue;
 679                         }
 680
 681                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 682                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 683                 }
 684         }
 685
 686         /**
 687          * Prepare the item array for an activity
 688          *
 689          * @param array      $activity   Activity array
 690          * @param string     $verb       Activity verb
 691          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 692          * @throws \ImagickException
 693          */
 694         public static function createActivity(array $activity, string $verb)
 695         {
 696                 $activity['reply-to-id'] = $activity['object_id'];
 697                 $item = self::createItem($activity, false);
 698                 if (empty($item)) {
 699                         Logger::debug('Activity was not prepared', ['id' => $activity['object_id']]);
 700                         return;
 701                 }
 702
 703                 $item['verb'] = $verb;
 704                 $item['thr-parent'] = $activity['object_id'];
 705                 $item['gravity'] = Item::GRAVITY_ACTIVITY;
 706                 unset($item['post-type']);
 707                 $item['object-type'] = Activity\ObjectType::NOTE;
 708
 709                 if (!empty($activity['content'])) {
 710                         $item['body'] = HTML::toBBCode($activity['content']);
 711                 }
 712
 713                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 714
 715                 self::postItem($activity, $item);
 716         }
 717
 718         /**
 719          * Fetch the Uri-Id of a post for the "featured" collection
 720          *
 721          * @param array $activity
 722          * @return null|array
 723          */
 724         private static function getUriIdForFeaturedCollection(array $activity)
 725         {
 726                 $actor = APContact::getByURL($activity['actor']);
 727                 if (empty($actor)) {
 728                         return null;
 729                 }
 730
 731                 // Refetch the account when the "featured" collection is missing.
 732                 // This can be removed in a future version (end of 2022 should be good).
 733                 if (empty($actor['featured'])) {
 734                         $actor = APContact::getByURL($activity['actor'], true);
 735                         if (empty($actor)) {
 736                                 return null;
 737                         }
 738                 }
 739
 740                 $parent = Post::selectFirst(['uri-id', 'author-id'], ['uri' => $activity['object_id']]);
 741                 if (empty($parent['uri-id'])) {
 742                         if (self::fetchMissingActivity($activity['object_id'], $activity, '', Receiver::COMPLETION_AUTO)) {
 743                                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 744                         }
 745                 }
 746
 747                 if (!empty($parent['uri-id'])) {
 748                         $parent;
 749                 }
 750
 751                 return null;
 752         }
 753
 754         /**
 755          * Add a post to the "Featured" collection
 756          *
 757          * @param array $activity
 758          */
 759         public static function addToFeaturedCollection(array $activity)
 760         {
 761                 $post = self::getUriIdForFeaturedCollection($activity);
 762                 if (empty($post)) {
 763                         return;
 764                 }
 765
 766                 Logger::debug('Add post to featured collection', ['post' => $post]);
 767
 768                 Post\Collection::add($post['uri-id'], Post\Collection::FEATURED, $post['author-id']);
 769                 Queue::remove($activity);
 770         }
 771
 772         /**
 773          * Remove a post to the "Featured" collection
 774          *
 775          * @param array $activity
 776          */
 777         public static function removeFromFeaturedCollection(array $activity)
 778         {
 779                 $post = self::getUriIdForFeaturedCollection($activity);
 780                 if (empty($post)) {
 781                         return;
 782                 }
 783
 784                 Logger::debug('Remove post from featured collection', ['post' => $post]);
 785
 786                 Post\Collection::remove($post['uri-id'], Post\Collection::FEATURED);
 787                 Queue::remove($activity);
 788         }
 789
 790         /**
 791          * Create an event
 792          *
 793          * @param array $activity Activity array
 794          * @param array $item
 795          *
 796          * @return int event id
 797          * @throws \Exception
 798          */
 799         public static function createEvent(array $activity, array $item): int
 800         {
 801                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 802                 $event['desc']      = HTML::toBBCode($activity['content'] ?? '');
 803                 if (!empty($activity['start-time'])) {
 804                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 805                 }
 806                 if (!empty($activity['end-time'])) {
 807                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 808                 }
 809                 $event['nofinish']  = empty($event['finish']);
 810                 $event['location']  = $activity['location'];
 811                 $event['cid']       = $item['contact-id'];
 812                 $event['uid']       = $item['uid'];
 813                 $event['uri']       = $item['uri'];
 814                 $event['edited']    = $item['edited'];
 815                 $event['private']   = $item['private'];
 816                 $event['guid']      = $item['guid'];
 817                 $event['plink']     = $item['plink'];
 818                 $event['network']   = $item['network'];
 819                 $event['protocol']  = $item['protocol'];
 820                 $event['direction'] = $item['direction'];
 821                 $event['source']    = $item['source'];
 822
 823                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 824                 if (DBA::isResult($ev)) {
 825                         $event['id'] = $ev['id'];
 826                 }
 827
 828                 $event_id = Event::store($event);
 829
 830                 Logger::info('Event was stored', ['id' => $event_id]);
 831
 832                 return $event_id;
 833         }
 834
 835         /**
 836          * Process the content
 837          *
 838          * @param array $activity Activity array
 839          * @param array $item
 840          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 841          * @throws \Exception
 842          */
 843         private static function processContent(array $activity, array $item)
 844         {
 845                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 846                         $item['title'] = strip_tags($activity['name'] ?? '');
 847                         $content = Markdown::toBBCode($activity['content']);
 848                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 849                         $item['title'] = $activity['name'];
 850                         $content = $activity['content'];
 851                 } else {
 852                         // By default assume "text/html"
 853                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 854                         $content = HTML::toBBCode($activity['content'] ?? '');
 855                 }
 856
 857                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 858
 859                 if (!empty($activity['languages'])) {
 860                         $item['language'] = self::processLanguages($activity['languages']);
 861                 }
 862
 863                 if (!empty($activity['emojis'])) {
 864                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 865                 }
 866
 867                 $content = self::addMentionLinks($content, $activity['tags']);
 868
 869                 if (!empty($activity['quote-url'])) {
 870                         $id = Item::fetchByLink($activity['quote-url']);
 871                         if ($id) {
 872                                 $shared_item = Post::selectFirst(['uri-id'], ['id' => $id]);
 873                                 $item['quote-uri-id'] = $shared_item['uri-id'];
 874                         } elseif ($uri_id = ItemURI::getIdByURI($activity['quote-url'], false)) {
 875                                 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]);
 876                                 $item['quote-uri-id'] = $uri_id;
 877                         } else {
 878                                 Logger::info('Quote was not fetched', ['guid' => $item['guid'], 'uri-id' => $item['uri-id'], 'quote' => $activity['quote-url']]);
 879                         }
 880                 }
 881
 882                 if (!empty($activity['source'])) {
 883                         $item['body'] = $activity['source'];
 884                         $item['raw-body'] = $content;
 885
 886                         $quote_uri_id = Item::getQuoteUriId($item['body']);
 887                         if (empty($item['quote-uri-id']) && !empty($quote_uri_id)) {
 888                                 $item['quote-uri-id'] = $quote_uri_id;
 889                         }
 890
 891                         $item['body'] = BBCode::removeSharedData($item['body']);
 892                 } else {
 893                         $parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
 894                         if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == Item::GRAVITY_COMMENT)) {
 895                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 896                                 if (!DBA::isResult($parent)) {
 897                                         Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
 898                                         return false;
 899                                 }
 900                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 901                         }
 902                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 903                         $item['raw-body'] = $item['body'] = $content;
 904                 }
 905
 906                 if (!empty($item['author-id']) && ($item['author-id'] == $item['owner-id'])) {
 907                         foreach (Tag::getFromBody($item['body'], Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION]) as $tag) {
 908                                 $actor = APContact::getByURL($tag[2], false);
 909                                 if (($actor['type'] ?? 'Person') == 'Group') {
 910                                         Logger::debug('Group post detected via exclusive mention.', ['mention' => $actor['url'], 'actor' => $activity['actor'], 'author' => $activity['author']]);
 911                                         $item['isGroup']    = true;
 912                                         $item['group-link'] = $item['owner-link'] = $actor['url'];
 913                                         $item['owner-id']   = Contact::getIdForURL($actor['url']);
 914                                         break;
 915                                 }
 916                         }
 917                 }
 918
 919                 self::storeFromBody($item);
 920                 self::storeTags($item['uri-id'], $activity['tags']);
 921
 922                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 923
 924                 $item['location'] = $activity['location'];
 925
 926                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 927                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 928                 }
 929
 930                 $item['app'] = $activity['generator'];
 931
 932                 return $item;
 933         }
 934
 935         /**
 936          * Store hashtags and mentions
 937          *
 938          * @param array $item
 939          */
 940         private static function storeFromBody(array $item)
 941         {
 942                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 943                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 944
 945                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 946         }
 947
 948         /**
 949          * Generate a GUID out of an URL of an ActivityPub post.
 950          *
 951          * @param string $url message URL
 952          * @return string with GUID
 953          */
 954         private static function getGUIDByURL(string $url): string
 955         {
 956                 $parsed = parse_url($url);
 957
 958                 $host_hash = hash('crc32', $parsed['host']);
 959
 960                 unset($parsed["scheme"]);
 961                 unset($parsed["host"]);
 962
 963                 $path = implode("/", $parsed);
 964
 965                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 966         }
 967
 968         /**
 969          * Checks if an incoming message is wanted
 970          *
 971          * @param array $activity
 972          * @param array $item
 973          * @return boolean Is the message wanted?
 974          */
 975         private static function isSolicitedMessage(array $activity, array $item): bool
 976         {
 977                 // The checks are split to improve the support when searching why a message was accepted.
 978                 if (count($activity['receiver']) != 1) {
 979                         // The message has more than one receiver, so it is wanted.
 980                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 981                         return true;
 982                 }
 983
 984                 if ($item['private'] == Item::PRIVATE) {
 985                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 986                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 987                         return true;
 988                 }
 989
 990                 if (!empty($activity['from-relay'])) {
 991                         // We check relay posts at another place. When it arrived here, the message is already checked.
 992                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 993                         return true;
 994                 }
 995
 996                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUNCE])) {
 997                         // Manual completions and completions caused by reshares are allowed without any further checks.
 998                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 999                         return true;
1000                 }
1001
1002                 if ($item['gravity'] != Item::GRAVITY_PARENT) {
1003                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
1004                         // This can possibly be improved in the future.
1005                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
1006                         return true;
1007                 }
1008
1009                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
1010                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB, $activity['thread-completion'] ?? 0)) {
1011                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
1012                         return true;
1013                 } else {
1014                         return false;
1015                 }
1016         }
1017
1018         /**
1019          * Creates an item post
1020          *
1021          * @param array $activity Activity data
1022          * @param array $item     item array
1023          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1024          * @throws \ImagickException
1025          */
1026         public static function postItem(array $activity, array $item)
1027         {
1028                 if (empty($item)) {
1029                         return;
1030                 }
1031
1032                 $stored = false;
1033                 $success = false;
1034                 ksort($activity['receiver']);
1035
1036                 if (!self::isSolicitedMessage($activity, $item)) {
1037                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
1038                         if (!empty($activity['entry-id'])) {
1039                                 Queue::deleteById($activity['entry-id']);
1040                         }
1041                         return;
1042                 }
1043
1044                 foreach ($activity['receiver'] as $receiver) {
1045                         if ($receiver == -1) {
1046                                 continue;
1047                         }
1048
1049                         if (($receiver != 0) && empty($item['parent-uri-id']) && !empty($item['thr-parent-id'])) {
1050                                 $parent = Post::selectFirst(['parent-uri-id', 'parent-uri'], ['uri-id' => $item['thr-parent-id'], 'uid' => [0, $receiver]]);
1051                                 if (!empty($parent['parent-uri-id'])) {
1052                                         $item['parent-uri-id'] = $parent['parent-uri-id'];
1053                                         $item['parent-uri']    = $parent['parent-uri'];
1054                                 }
1055                         }
1056
1057                         $item['uid'] = $receiver;
1058
1059                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
1060                         switch($type) {
1061                                 case Receiver::TARGET_TO:
1062                                         $item['post-reason'] = Item::PR_TO;
1063                                         break;
1064                                 case Receiver::TARGET_CC:
1065                                         $item['post-reason'] = Item::PR_CC;
1066                                         break;
1067                                 case Receiver::TARGET_BTO:
1068                                         $item['post-reason'] = Item::PR_BTO;
1069                                         break;
1070                                 case Receiver::TARGET_BCC:
1071                                         $item['post-reason'] = Item::PR_BCC;
1072                                         break;
1073                                 case Receiver::TARGET_AUDIENCE:
1074                                         $item['post-reason'] = Item::PR_AUDIENCE;
1075                                         break;
1076                                 case Receiver::TARGET_FOLLOWER:
1077                                         $item['post-reason'] = Item::PR_FOLLOWER;
1078                                         break;
1079                                 case Receiver::TARGET_ANSWER:
1080                                         $item['post-reason'] = Item::PR_COMMENT;
1081                                         break;
1082                                 case Receiver::TARGET_GLOBAL:
1083                                         $item['post-reason'] = Item::PR_GLOBAL;
1084                                         break;
1085                                 default:
1086                                         $item['post-reason'] = Item::PR_NONE;
1087                         }
1088
1089                         $item['post-reason'] = Item::getPostReason($item);
1090
1091                         if (in_array($item['post-reason'], [Item::PR_GLOBAL, Item::PR_NONE])) {
1092                                 if (!empty($activity['from-relay'])) {
1093                                         $item['post-reason'] = Item::PR_RELAY;
1094                                 } elseif (!empty($activity['thread-completion'])) {
1095                                         $item['post-reason'] = Item::PR_FETCHED;
1096                                 } elseif (!empty($activity['push'])) {
1097                                         $item['post-reason'] = Item::PR_PUSHED;
1098                                 }
1099                         } elseif (($item['post-reason'] == Item::PR_FOLLOWER) && !empty($activity['from-relay'])) {
1100                                 // When a post arrives via a relay and we follow the author, we have to override the causer.
1101                                 // Otherwise the system assumes that we follow the relay. (See "addRowInformation")
1102                                 Logger::debug('Relay post for follower', ['receiver' => $receiver, 'guid' => $item['guid'], 'relay' => $activity['from-relay']]);
1103                                 $item['causer-id'] = ($item['gravity'] == Item::GRAVITY_PARENT) ? $item['owner-id'] : $item['author-id'];
1104                         }
1105
1106                         if ($item['isGroup']) {
1107                                 $item['contact-id'] = Contact::getIdForURL($item['group-link'], $receiver);
1108                         } else {
1109                                 $item['contact-id'] = Contact::getIdForURL($item['author-link'], $receiver);
1110                         }
1111
1112                         if (($receiver != 0) && empty($item['contact-id'])) {
1113                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
1114                         }
1115
1116                         if (!empty($activity['directmessage'])) {
1117                                 self::postMail($activity, $item);
1118                                 continue;
1119                         }
1120
1121                         if (($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])) {
1122                                 if (!$item['isGroup']) {
1123                                         if ($item['post-reason'] == Item::PR_BCC) {
1124                                                 Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id'], 'url' => $item['uri']]);
1125                                                 continue;
1126                                         }
1127
1128                                         if ((DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE)
1129                                                 && in_array($activity['thread-children-type'] ?? '', Receiver::ACTIVITY_TYPES)) {
1130                                                 Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
1131                                                         ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
1132                                                 continue;
1133                                         }
1134                                 }
1135
1136                                 $isGroup = false;
1137                                 $user = User::getById($receiver, ['account-type']);
1138                                 if (!empty($user['account-type'])) {
1139                                         $isGroup = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
1140                                 }
1141
1142                                 if ((DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE)
1143                                         && ((!$isGroup && !$item['isGroup'] && ($activity['type'] != 'as:Announce'))
1144                                         || !Contact::isSharingByURL($activity['actor'], $receiver))) {
1145                                         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']]);
1146                                         continue;
1147                                 }
1148
1149                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
1150                         }
1151
1152                         if (!self::hasParents($item, $receiver)) {
1153                                 continue;
1154                         }
1155
1156                         if (($item['gravity'] != Item::GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
1157                                 $event_id = self::createEvent($activity, $item);
1158
1159                                 $item = Event::getItemArrayForImportedId($event_id, $item);
1160                         }
1161
1162                         $item_id = Item::insert($item);
1163                         if ($item_id) {
1164                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
1165                                 $success = true;
1166                         } else {
1167                                 Logger::notice('Item insertion aborted', ['uri' => $item['uri'], 'uid' => $item['uid']]);
1168                                 if (($item['uid'] == 0) && (count($activity['receiver']) > 1)) {
1169                                         Logger::info('Public item was aborted. We skip for all users.', ['uri' => $item['uri']]);
1170                                         break;
1171                                 }
1172                         }
1173
1174                         if ($item['uid'] == 0) {
1175                                 $stored = $item_id;
1176                         }
1177                 }
1178
1179                 Queue::remove($activity);
1180
1181                 if ($success && Queue::hasChildren($item['uri']) && Post::exists(['uri' => $item['uri']])) {
1182                         Queue::processReplyByUri($item['uri']);
1183                 }
1184
1185                 // Store send a follow request for every reshare - but only when the item had been stored
1186                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == Item::GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
1187                         $author = APContact::getByURL($item['owner-link'], false);
1188                         // We send automatic follow requests for reshared messages. (We don't need though for group posts)
1189                         if ($author['type'] != 'Group') {
1190                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
1191                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
1192                         }
1193                 }
1194         }
1195
1196         /**
1197          * Checks if there are parent posts for the given receiver.
1198          * If not, then the system will try to add them.
1199          *
1200          * @param array $item
1201          * @param integer $receiver
1202          * @return boolean
1203          */
1204         private static function hasParents(array $item, int $receiver)
1205         {
1206                 if (($receiver == 0) || ($item['gravity'] == Item::GRAVITY_PARENT)) {
1207                         return true;
1208                 }
1209
1210                 $fields = ['causer-id' => $item['causer-id'] ?? $item['author-id'], 'post-reason' => Item::PR_FETCHED];
1211
1212                 $add_parent = true;
1213
1214                 if ($item['verb'] != Activity::ANNOUNCE) {
1215                         switch (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer')) {
1216                                 case Item::COMPLETION_COMMENT:
1217                                         $add_parent = ($item['gravity'] != Item::GRAVITY_ACTIVITY);
1218                                         break;
1219
1220                                 case Item::COMPLETION_NONE:
1221                                         $add_parent = false;
1222                                         break;
1223                         }
1224                 }
1225
1226                 if ($add_parent) {
1227                         $add_parent = Contact::isSharing($fields['causer-id'], $receiver);
1228                         if (!$add_parent && ($item['author-id'] != $fields['causer-id'])) {
1229                                 $add_parent = Contact::isSharing($item['author-id'], $receiver);
1230                         }
1231                         if (!$add_parent && !in_array($item['owner-id'], [$fields['causer-id'], $item['author-id']])) {
1232                                 $add_parent = Contact::isSharing($item['owner-id'], $receiver);
1233                         }
1234                 }
1235
1236                 $has_parents = false;
1237
1238                 if (!empty($item['parent-uri-id'])) {
1239                         if (Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => $receiver])) {
1240                                 $has_parents = true;
1241                         } elseif ($add_parent && Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => 0])) {
1242                                 $stored = Item::storeForUserByUriId($item['parent-uri-id'], $receiver, $fields);
1243                                 $has_parents = (bool)$stored;
1244                                 if ($stored) {
1245                                         Logger::notice('Inserted missing parent post', ['stored' => $stored, 'uid' => $receiver, 'parent' => $item['parent-uri']]);
1246                                 } else {
1247                                         Logger::notice('Parent could not be added.', ['uid' => $receiver, 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1248                                         return false;
1249                                 }
1250                         } elseif ($add_parent) {
1251                                 Logger::debug('Parent does not exist.', ['uid' => $receiver, 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1252                         } else {
1253                                 Logger::debug('Parent should not be added.', ['uid' => $receiver, 'gravity' => $item['gravity'], 'verb' => $item['verb'], 'guid' => $item['guid'], 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1254                         }
1255                 }
1256
1257                 if (empty($item['parent-uri-id']) || ($item['thr-parent-id'] != $item['parent-uri-id'])) {
1258                         if (Post::exists(['uri-id' => $item['thr-parent-id'], 'uid' => $receiver])) {
1259                                 $has_parents = true;
1260                         } elseif (($has_parents || $add_parent) && Post::exists(['uri-id' => $item['thr-parent-id'], 'uid' => 0])) {
1261                                 $stored = Item::storeForUserByUriId($item['thr-parent-id'], $receiver, $fields);
1262                                 $has_parents = $has_parents || (bool)$stored;
1263                                 if ($stored) {
1264                                         Logger::notice('Inserted missing thread parent post', ['stored' => $stored, 'uid' => $receiver, 'thread-parent' => $item['thr-parent']]);
1265                                 } else {
1266                                         Logger::notice('Thread parent could not be added.', ['uid' => $receiver, 'uri' => $item['uri'], 'thread-parent' => $item['thr-parent']]);
1267                                 }
1268                         } elseif ($add_parent) {
1269                                 Logger::debug('Thread parent does not exist.', ['uid' => $receiver, 'uri' => $item['uri'], 'thread-parent' => $item['thr-parent']]);
1270                         } else {
1271                                 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']]);
1272                         }
1273                 }
1274
1275                 return $has_parents;
1276         }
1277
1278         /**
1279          * Store tags and mentions into the tag table
1280          *
1281          * @param integer $uriid
1282          * @param array $tags
1283          */
1284         private static function storeTags(int $uriid, array $tags = null)
1285         {
1286                 foreach ($tags as $tag) {
1287                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1288                                 continue;
1289                         }
1290
1291                         $hash = substr($tag['name'], 0, 1);
1292
1293                         if ($tag['type'] == 'Mention') {
1294                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
1295                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
1296                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
1297                                         $tag['name'] = substr($tag['name'], 1);
1298                                 }
1299                                 $type = Tag::IMPLICIT_MENTION;
1300
1301                                 if (!empty($tag['href'])) {
1302                                         $apcontact = APContact::getByURL($tag['href']);
1303                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
1304                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
1305                                         }
1306                                 }
1307                         } elseif ($tag['type'] == 'Hashtag') {
1308                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
1309                                         $tag['name'] = substr($tag['name'], 1);
1310                                 }
1311                                 $type = Tag::HASHTAG;
1312                         }
1313
1314                         if (empty($tag['name'])) {
1315                                 continue;
1316                         }
1317
1318                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
1319                 }
1320         }
1321
1322         public static function storeReceivers(int $uriid, array $receivers)
1323         {
1324                 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 => $type) {
1325                         if (!empty($receivers[$element])) {
1326                                 foreach ($receivers[$element] as $receiver) {
1327                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
1328                                                 $name = Receiver::PUBLIC_COLLECTION;
1329                                         } elseif ($path = parse_url($receiver, PHP_URL_PATH)) {
1330                                                 $name = trim($path, '/');
1331                                         } elseif ($host = parse_url($receiver, PHP_URL_HOST)) {
1332                                                 $name = $host;
1333                                         } else {
1334                                                 Logger::warning('Unable to coerce name from receiver', ['element' => $element, 'type' => $type, 'receiver' => $receiver]);
1335                                                 $name = '';
1336                                         }
1337
1338                                         $target = Tag::getTargetType($receiver);
1339                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
1340                                         Tag::store($uriid, $type, $name, $receiver, $target);
1341                                 }
1342                         }
1343                 }
1344         }
1345
1346         /**
1347          * Creates an mail post
1348          *
1349          * @param array $activity Activity data
1350          * @param array $item     item array
1351          * @return int|bool New mail table row id or false on error
1352          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1353          */
1354         private static function postMail(array $activity, array $item)
1355         {
1356                 if (($item['gravity'] != Item::GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
1357                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
1358                         return false;
1359                 }
1360
1361                 Logger::info('Direct Message', $item);
1362
1363                 $msg = [];
1364                 $msg['uid'] = $item['uid'];
1365
1366                 $msg['contact-id'] = $item['contact-id'];
1367
1368                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1369                 $msg['from-name'] = $contact['name'];
1370                 $msg['from-url'] = $contact['url'];
1371                 $msg['from-photo'] = $contact['photo'];
1372
1373                 $msg['uri'] = $item['uri'];
1374                 $msg['created'] = $item['created'];
1375
1376                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1377                 if (DBA::isResult($parent)) {
1378                         $msg['parent-uri'] = $parent['parent-uri'];
1379                         $msg['title'] = $parent['title'];
1380                 } else {
1381                         $msg['parent-uri'] = $item['thr-parent'];
1382
1383                         if (!empty($item['title'])) {
1384                                 $msg['title'] = $item['title'];
1385                         } elseif (!empty($item['content-warning'])) {
1386                                 $msg['title'] = $item['content-warning'];
1387                         } else {
1388                                 // Trying to generate a title out of the body
1389                                 $title = $item['body'];
1390
1391                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1392                                         $title = $matches[3];
1393                                 }
1394
1395                                 $title = trim(BBCode::toPlaintext($title));
1396
1397                                 if (strlen($title) > 20) {
1398                                         $title = substr($title, 0, 20) . '...';
1399                                 }
1400
1401                                 $msg['title'] = $title;
1402                         }
1403                 }
1404                 $msg['body'] = $item['body'];
1405
1406                 return Mail::insert($msg);
1407         }
1408
1409         /**
1410          * Fetch featured posts from a contact with the given url
1411          *
1412          * @param string $url
1413          * @return void
1414          */
1415         public static function fetchFeaturedPosts(string $url)
1416         {
1417                 Logger::info('Fetch featured posts', ['contact' => $url]);
1418
1419                 $apcontact = APContact::getByURL($url);
1420                 if (empty($apcontact['featured'])) {
1421                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1422                         return;
1423                 }
1424
1425                 $pcid = Contact::getIdForURL($url, 0, false);
1426                 if (empty($pcid)) {
1427                         Logger::notice('Contact not found', ['contact' => $url]);
1428                         return;
1429                 }
1430
1431                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1432                 if (!empty($posts)) {
1433                         $old_featured = array_column($posts, 'uri-id');
1434                 } else {
1435                         $old_featured = [];
1436                 }
1437
1438                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1439                 if (empty($featured)) {
1440                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1441
1442                         foreach ($old_featured as $uri_id) {
1443                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1444                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1445                         }
1446                         return;
1447                 }
1448
1449                 $new = 0;
1450                 $old = 0;
1451
1452                 foreach ($featured as $post) {
1453                         if (empty($post['id'])) {
1454                                 continue;
1455                         }
1456                         $id = Item::fetchByLink($post['id']);
1457                         if (!empty($id)) {
1458                                 $item = Post::selectFirst(['uri-id', 'featured', 'author-id'], ['id' => $id]);
1459                                 if (!empty($item['uri-id'])) {
1460                                         if (!$item['featured']) {
1461                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED, $item['author-id']);
1462                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1463                                                 $new++;
1464                                         } else {
1465                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1466                                                 $old++;
1467                                         }
1468
1469                                         $index = array_search($item['uri-id'], $old_featured);
1470                                         if (!($index === false)) {
1471                                                 unset($old_featured[$index]);
1472                                         }
1473                                 }
1474                         }
1475                 }
1476
1477                 foreach ($old_featured as $uri_id) {
1478                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1479                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1480                 }
1481
1482                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1483         }
1484
1485         public static function fetchCachedActivity(string $url, int $uid): array
1486         {
1487                 $cachekey = self::CACHEKEY_FETCH_ACTIVITY . $uid . ':' . hash('sha256', $url);
1488                 $object = DI::cache()->get($cachekey);
1489
1490                 if (!is_null($object)) {
1491                         if (!empty($object)) {
1492                                 Logger::debug('Fetch from cache', ['url' => $url, 'uid' => $uid]);
1493                         } else {
1494                                 Logger::debug('Fetch from negative cache', ['url' => $url, 'uid' => $uid]);
1495                         }
1496                         return $object;
1497                 }
1498
1499                 $object = ActivityPub::fetchContent($url, $uid);
1500                 if (empty($object)) {
1501                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
1502                         // We perform negative caching.
1503                         DI::cache()->set($cachekey, [], Duration::FIVE_MINUTES);
1504                         return [];
1505                 }
1506
1507                 if (empty($object['id'])) {
1508                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1509                         return [];
1510                 }
1511                 DI::cache()->set($cachekey, $object, Duration::FIVE_MINUTES);
1512
1513                 Logger::debug('Activity was fetched successfully', ['url' => $url, 'uid' => $uid]);
1514
1515                 return $object;
1516         }
1517
1518         /**
1519          * Fetches missing posts
1520          *
1521          * @param string     $url         message URL
1522          * @param array      $child       activity array with the child of this message
1523          * @param string     $relay_actor Relay actor
1524          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1525          * @param int        $uid         User id that is used to fetch the activity
1526          * @return string fetched message URL
1527          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1528          * @throws \ImagickException
1529          */
1530         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL, int $uid = 0): string
1531         {
1532                 $object = self::fetchCachedActivity($url, $uid);
1533                 if (empty($object)) {
1534                         return '';
1535                 }
1536
1537                 $signer = [];
1538
1539                 if (!empty($object['attributedTo'])) {
1540                         $attributed_to = $object['attributedTo'];
1541                         if (is_array($attributed_to)) {
1542                                 $compacted = JsonLD::compact($object);
1543                                 $attributed_to = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1544                         }
1545                         $signer[] = $attributed_to;
1546                 }
1547
1548                 if (!empty($object['actor'])) {
1549                         $object_actor = $object['actor'];
1550                 } elseif (!empty($attributed_to)) {
1551                         $object_actor = $attributed_to;
1552                 } else {
1553                         // Shouldn't happen
1554                         $object_actor = '';
1555                 }
1556
1557                 $signer[] = $object_actor;
1558
1559                 if (!empty($child['author'])) {
1560                         $actor = $child['author'];
1561                         $signer[] = $actor;
1562                 } else {
1563                         $actor = $object_actor;
1564                 }
1565
1566                 if (!empty($object['published'])) {
1567                         $published = $object['published'];
1568                 } elseif (!empty($child['published'])) {
1569                         $published = $child['published'];
1570                 } else {
1571                         $published = DateTimeFormat::utcNow();
1572                 }
1573
1574                 $activity = [];
1575                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1576                 unset($object['@context']);
1577                 $activity['id'] = $object['id'];
1578                 $activity['to'] = $object['to'] ?? [];
1579                 $activity['cc'] = $object['cc'] ?? [];
1580                 $activity['audience'] = $object['audience'] ?? [];
1581                 $activity['actor'] = $actor;
1582                 $activity['object'] = $object;
1583                 $activity['published'] = $published;
1584                 $activity['type'] = 'Create';
1585
1586                 $ldactivity = JsonLD::compact($activity);
1587
1588                 $ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 0;
1589
1590                 if ($object_actor != $actor) {
1591                         Contact::updateByUrlIfNeeded($object_actor);
1592                 }
1593
1594                 Contact::updateByUrlIfNeeded($actor);
1595
1596                 if (!empty($child['thread-completion'])) {
1597                         $ldactivity['thread-completion'] = $child['thread-completion'];
1598                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1599                 } else {
1600                         $ldactivity['thread-completion'] = Contact::getIdForURL($relay_actor ?: $actor);
1601                         $ldactivity['completion-mode']   = $completion;
1602                 }
1603
1604                 if ($completion == Receiver::COMPLETION_RELAY) {
1605                         $ldactivity['from-relay'] = $ldactivity['thread-completion'];
1606                         if (!self::acceptIncomingMessage($ldactivity, $object['id'])) {
1607                                 return '';
1608                         }
1609                 }
1610
1611                 if (!empty($child['thread-children-type'])) {
1612                         $ldactivity['thread-children-type'] = $child['thread-children-type'];
1613                 } elseif (!empty($child['type'])) {
1614                         $ldactivity['thread-children-type'] = $child['type'];
1615                 } else {
1616                         $ldactivity['thread-children-type'] = 'as:Create';
1617                 }
1618
1619                 if (($completion == Receiver::COMPLETION_RELAY) && Queue::exists($url, 'as:Create')) {
1620                         Logger::info('Activity has already been queued.', ['url' => $url, 'object' => $activity['id']]);
1621                 } elseif (ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer, '', $completion)) {
1622                         Logger::info('Activity had been fetched and processed.', ['url' => $url, 'entry' => $child['entry-id'] ?? 0, 'completion' => $completion, 'object' => $activity['id']]);
1623                 } else {
1624                         Logger::info('Activity had been fetched and will be processed later.', ['url' => $url, 'entry' => $child['entry-id'] ?? 0, 'completion' => $completion, 'object' => $activity['id']]);
1625                 }
1626
1627                 return $activity['id'];
1628         }
1629
1630         /**
1631          * Test if incoming relay messages should be accepted
1632          *
1633          * @param array $activity activity array
1634          * @param string $id      object ID
1635          * @return boolean true if message is accepted
1636          */
1637         private static function acceptIncomingMessage(array $activity, string $id): bool
1638         {
1639                 if (empty($activity['as:object'])) {
1640                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1641                         return true;
1642                 }
1643
1644                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1645                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1646                 if (Post::exists(['uri-id' => $uriid])) {
1647                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1648                         return true;
1649                 }
1650
1651                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1652                 $authorid = Contact::getIdForURL($attributed_to);
1653
1654                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1655
1656                 $messageTags = [];
1657                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1658                 if (!empty($tags)) {
1659                         foreach ($tags as $tag) {
1660                                 if ($tag['type'] != 'Hashtag') {
1661                                         continue;
1662                                 }
1663                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1664                         }
1665                 }
1666
1667                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB, $activity['thread-completion'] ?? 0);
1668         }
1669
1670         /**
1671          * perform a "follow" request
1672          *
1673          * @param array $activity
1674          * @return void
1675          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1676          * @throws \ImagickException
1677          */
1678         public static function followUser(array $activity)
1679         {
1680                 $uid = User::getIdForURL($activity['object_id']);
1681                 if (empty($uid)) {
1682                         Queue::remove($activity);
1683                         return;
1684                 }
1685
1686                 $owner = User::getOwnerDataById($uid);
1687                 if (empty($owner)) {
1688                         return;
1689                 }
1690
1691                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1692                 if (!empty($cid)) {
1693                         self::switchContact($cid);
1694                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1695                 }
1696
1697                 $item = [
1698                         'author-id' => Contact::getIdForURL($activity['actor']),
1699                         'author-link' => $activity['actor'],
1700                 ];
1701
1702                 // Ensure that the contact has got the right network type
1703                 self::switchContact($item['author-id']);
1704
1705                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1706                 if ($result === true) {
1707                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1708                 }
1709
1710                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1711                 if (empty($cid)) {
1712                         return;
1713                 }
1714
1715                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1716                         self::transmitPendingEvents($cid, $owner['uid']);
1717                 }
1718
1719                 if (empty($contact)) {
1720                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1721                 }
1722                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1723                 Queue::remove($activity);
1724         }
1725
1726         /**
1727          * Transmit pending events to the new follower
1728          *
1729          * @param integer $cid Contact id
1730          * @param integer $uid User id
1731          * @return void
1732          */
1733         private static function transmitPendingEvents(int $cid, int $uid)
1734         {
1735                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1736                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1737
1738                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1739                 while ($event = DBA::fetch($events)) {
1740                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1741                         if (empty($post)) {
1742                                 continue;
1743                         }
1744                         if (DI::config()->get('system', 'bulk_delivery')) {
1745                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1746                                 Worker::add(Worker::PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1747                         } else {
1748                                 Worker::add(Worker::PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1749                         }
1750                 }
1751         }
1752
1753         /**
1754          * Update the given profile
1755          *
1756          * @param array $activity
1757          * @throws \Exception
1758          */
1759         public static function updatePerson(array $activity)
1760         {
1761                 if (empty($activity['object_id'])) {
1762                         return;
1763                 }
1764
1765                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1766                 Contact::updateFromProbeByURL($activity['object_id']);
1767                 Queue::remove($activity);
1768         }
1769
1770         /**
1771          * Delete the given profile
1772          *
1773          * @param array $activity
1774          * @return void
1775          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1776          */
1777         public static function deletePerson(array $activity)
1778         {
1779                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1780                         Logger::info('Empty object id or actor.');
1781                         Queue::remove($activity);
1782                         return;
1783                 }
1784
1785                 if ($activity['object_id'] != $activity['actor']) {
1786                         Logger::info('Object id does not match actor.');
1787                         Queue::remove($activity);
1788                         return;
1789                 }
1790
1791                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1792                 while ($contact = DBA::fetch($contacts)) {
1793                         Contact::remove($contact['id']);
1794                 }
1795                 DBA::close($contacts);
1796
1797                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1798                 Queue::remove($activity);
1799         }
1800
1801         /**
1802          * Add moved contacts as followers for all subscribers of the old contact
1803          *
1804          * @param array $activity
1805          * @return void
1806          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1807          */
1808         public static function movePerson(array $activity)
1809         {
1810                 if (empty($activity['target_id']) || empty($activity['object_id'])) {
1811                         Queue::remove($activity);
1812                         return;
1813                 }
1814
1815                 if ($activity['object_id'] != $activity['actor']) {
1816                         Logger::notice('Object is not the actor', ['activity' => $activity]);
1817                         Queue::remove($activity);
1818                         return;
1819                 }
1820
1821                 $from = Contact::getByURL($activity['object_id'], false, ['uri-id']);
1822                 if (empty($from['uri-id'])) {
1823                         Logger::info('Object not found', ['activity' => $activity]);
1824                         Queue::remove($activity);
1825                         return;
1826                 }
1827
1828                 $contacts = DBA::select('contact', ['uid', 'url'], ["`uri-id` = ? AND `uid` != ? AND `rel` IN (?, ?)", $from['uri-id'], 0, Contact::FRIEND, Contact::SHARING]);
1829                 while ($from_contact = DBA::fetch($contacts)) {
1830                         $result = Contact::createFromProbeForUser($from_contact['uid'], $activity['target_id']);
1831                         Logger::debug('Follower added', ['from' => $from_contact, 'result' => $result]);
1832                 }
1833                 DBA::close($contacts);
1834                 Queue::remove($activity);
1835         }
1836
1837         /**
1838          * Blocks the user by the contact
1839          *
1840          * @param array $activity
1841          * @return void
1842          * @throws \Exception
1843          */
1844         public static function blockAccount(array $activity)
1845         {
1846                 $cid = Contact::getIdForURL($activity['actor']);
1847                 if (empty($cid)) {
1848                         return;
1849                 }
1850
1851                 $uid = User::getIdForURL($activity['object_id']);
1852                 if (empty($uid)) {
1853                         return;
1854                 }
1855
1856                 Contact\User::setIsBlocked($cid, $uid, true);
1857
1858                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1859                 Queue::remove($activity);
1860         }
1861
1862         /**
1863          * Unblocks the user by the contact
1864          *
1865          * @param array $activity
1866          * @return void
1867          * @throws \Exception
1868          */
1869         public static function unblockAccount(array $activity)
1870         {
1871                 $cid = Contact::getIdForURL($activity['actor']);
1872                 if (empty($cid)) {
1873                         return;
1874                 }
1875
1876                 $uid = User::getIdForURL($activity['object_object']);
1877                 if (empty($uid)) {
1878                         return;
1879                 }
1880
1881                 Contact\User::setIsBlocked($cid, $uid, false);
1882
1883                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1884                 Queue::remove($activity);
1885         }
1886
1887         /**
1888          * Report a user
1889          *
1890          * @param array $activity
1891          * @return void
1892          * @throws \Exception
1893          */
1894         public static function ReportAccount(array $activity)
1895         {
1896                 $account_id = Contact::getIdForURL($activity['object_id']);
1897                 if (empty($account_id)) {
1898                         Logger::info('Unknown account', ['activity' => $activity]);
1899                         Queue::remove($activity);
1900                         return;
1901                 }
1902
1903                 $reporter_id = Contact::getIdForURL($activity['actor']);
1904                 if (empty($reporter_id)) {
1905                         Logger::info('Unknown actor', ['activity' => $activity]);
1906                         Queue::remove($activity);
1907                         return;
1908                 }
1909
1910                 $uri_ids = [];
1911                 foreach ($activity['object_ids'] as $status_id) {
1912                         $post = Post::selectFirst(['uri-id'], ['uri' => $status_id]);
1913                         if (!empty($post['uri-id'])) {
1914                                 $uri_ids[] = $post['uri-id'];
1915                         }
1916                 }
1917
1918                 $report = DI::reportFactory()->createFromReportsRequest($reporter_id, $account_id, $activity['content'], null, '', false, $uri_ids);
1919                 DI::report()->save($report);
1920
1921                 Logger::info('Stored report', ['reporter' => $reporter_id, 'account_id' => $account_id, 'comment' => $activity['content'], 'object_ids' => $activity['object_ids']]);
1922         }
1923
1924         /**
1925          * Accept a follow request
1926          *
1927          * @param array $activity
1928          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1929          * @throws \ImagickException
1930          */
1931         public static function acceptFollowUser(array $activity)
1932         {
1933                 if (!empty($activity['object_actor'])) {
1934                         $uid      = User::getIdForURL($activity['object_actor']);
1935                         $check_id = false;
1936                 } elseif (!empty($activity['receiver']) && (count($activity['receiver']) == 1)) {
1937                         $uid      = array_shift($activity['receiver']);
1938                         $check_id = true;
1939                 }
1940
1941                 if (empty($uid)) {
1942                         Logger::notice('User could not be detected', ['activity' => $activity]);
1943                         Queue::remove($activity);
1944                         return;
1945                 }
1946
1947                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1948                 if (empty($cid)) {
1949                         Logger::notice('No contact found', ['actor' => $activity['actor']]);
1950                         Queue::remove($activity);
1951                         return;
1952                 }
1953
1954                 $id = Transmitter::activityIDFromContact($cid);
1955                 if ($id == $activity['object_id']) {
1956                         Logger::info('Successful id check', ['uid' => $uid, 'cid' => $cid]);
1957                 } else {
1958                         Logger::info('Unsuccessful id check', ['uid' => $uid, 'cid' => $cid, 'id' => $id, 'object_id' => $activity['object_id']]);
1959                         if ($check_id) {
1960                                 Queue::remove($activity);
1961                                 return;
1962                         }
1963                 }
1964
1965                 self::switchContact($cid);
1966
1967                 $fields = ['pending' => false];
1968
1969                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1970                 if ($contact['rel'] == Contact::FOLLOWER) {
1971                         $fields['rel'] = Contact::FRIEND;
1972                 }
1973
1974                 $condition = ['id' => $cid];
1975                 Contact::update($fields, $condition);
1976                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1977                 Queue::remove($activity);
1978         }
1979
1980         /**
1981          * Reject a follow request
1982          *
1983          * @param array $activity
1984          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1985          * @throws \ImagickException
1986          */
1987         public static function rejectFollowUser(array $activity)
1988         {
1989                 $uid = User::getIdForURL($activity['object_actor']);
1990                 if (empty($uid)) {
1991                         return;
1992                 }
1993
1994                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1995                 if (empty($cid)) {
1996                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1997                         return;
1998                 }
1999
2000                 self::switchContact($cid);
2001
2002                 $contact = Contact::getById($cid, ['rel']);
2003                 if ($contact['rel'] == Contact::SHARING) {
2004                         Contact::remove($cid);
2005                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
2006                 } elseif ($contact['rel'] == Contact::FRIEND) {
2007                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
2008                 } else {
2009                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
2010                 }
2011                 Queue::remove($activity);
2012         }
2013
2014         /**
2015          * Undo activity like "like" or "dislike"
2016          *
2017          * @param array $activity
2018          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2019          * @throws \ImagickException
2020          */
2021         public static function undoActivity(array $activity)
2022         {
2023                 if (empty($activity['object_id'])) {
2024                         return;
2025                 }
2026
2027                 if (empty($activity['object_actor'])) {
2028                         return;
2029                 }
2030
2031                 $author_id = Contact::getIdForURL($activity['object_actor']);
2032                 if (empty($author_id)) {
2033                         return;
2034                 }
2035
2036                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => Item::GRAVITY_ACTIVITY]);
2037                 Queue::remove($activity);
2038         }
2039
2040         /**
2041          * Activity to remove a follower
2042          *
2043          * @param array $activity
2044          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2045          * @throws \ImagickException
2046          */
2047         public static function undoFollowUser(array $activity)
2048         {
2049                 $uid = User::getIdForURL($activity['object_object']);
2050                 if (empty($uid)) {
2051                         return;
2052                 }
2053
2054                 $owner = User::getOwnerDataById($uid);
2055                 if (empty($owner)) {
2056                         return;
2057                 }
2058
2059                 $cid = Contact::getIdForURL($activity['actor'], $uid);
2060                 if (empty($cid)) {
2061                         Logger::info('No contact found', ['actor' => $activity['actor']]);
2062                         return;
2063                 }
2064
2065                 self::switchContact($cid);
2066
2067                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
2068                 if (!DBA::isResult($contact)) {
2069                         return;
2070                 }
2071
2072                 Contact::removeFollower($contact);
2073                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
2074                 Queue::remove($activity);
2075         }
2076
2077         /**
2078          * Switches a contact to AP if needed
2079          *
2080          * @param integer $cid Contact ID
2081          * @return void
2082          * @throws \Exception
2083          */
2084         private static function switchContact(int $cid)
2085         {
2086                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
2087                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
2088                         return;
2089                 }
2090
2091                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
2092                 Contact::updateFromProbe($cid);
2093         }
2094
2095         /**
2096          * Collects implicit mentions like:
2097          * - the author of the parent item
2098          * - all the mentioned conversants in the parent item
2099          *
2100          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
2101          * @return array
2102          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2103          */
2104         private static function getImplicitMentionList(array $parent): array
2105         {
2106                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
2107
2108                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
2109
2110                 $implicit_mentions = [];
2111                 if (empty($parent_author['url'])) {
2112                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
2113                 } else {
2114                         $implicit_mentions[] = $parent_author['url'];
2115                         $implicit_mentions[] = $parent_author['nurl'];
2116                         $implicit_mentions[] = $parent_author['alias'];
2117                 }
2118
2119                 if (!empty($parent['alias'])) {
2120                         $implicit_mentions[] = $parent['alias'];
2121                 }
2122
2123                 foreach ($parent_terms as $term) {
2124                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
2125                         if (!empty($contact['url'])) {
2126                                 $implicit_mentions[] = $contact['url'];
2127                                 $implicit_mentions[] = $contact['nurl'];
2128                                 $implicit_mentions[] = $contact['alias'];
2129                         }
2130                 }
2131
2132                 return $implicit_mentions;
2133         }
2134
2135         /**
2136          * Strips from the body prepended implicit mentions
2137          *
2138          * @param string $body
2139          * @param array $parent
2140          * @return string
2141          */
2142         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
2143         {
2144                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
2145                         return $body;
2146                 }
2147
2148                 $potential_mentions = self::getImplicitMentionList($parent);
2149
2150                 $kept_mentions = [];
2151
2152                 // Extract one prepended mention at a time from the body
2153                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
2154                         if (!in_array($matches[2], $potential_mentions)) {
2155                                 $kept_mentions[] = $matches[1];
2156                         }
2157
2158                         $body = $matches[3];
2159                 }
2160
2161                 // Re-appending the kept mentions to the body after extraction
2162                 $kept_mentions[] = $body;
2163
2164                 return implode('', $kept_mentions);
2165         }
2166
2167         /**
2168          * Adds links to string mentions
2169          *
2170          * @param string $body
2171          * @param array  $tags
2172          * @return string
2173          */
2174         protected static function addMentionLinks(string $body, array $tags): string
2175         {
2176                 // This prevents links to be added again to Pleroma-style mention links
2177                 $body = self::normalizeMentionLinks($body);
2178
2179                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
2180                         foreach ($tags as $tag) {
2181                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
2182                                         continue;
2183                                 }
2184
2185                                 $hash = substr($tag['name'], 0, 1);
2186                                 $name = substr($tag['name'], 1);
2187                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
2188                                         $hash = '';
2189                                         $name = $tag['name'];
2190                                 }
2191
2192                                 if (Network::isValidHttpUrl($tag['href'])) {
2193                                         $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
2194                                 }
2195                         }
2196
2197                         return $body;
2198                 });
2199
2200                 return $body;
2201         }
2202 }