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\Moderation\Entity\Report;
  46 use Friendica\Protocol\Activity;
  47 use Friendica\Protocol\ActivityPub;
  48 use Friendica\Protocol\Delivery;
  49 use Friendica\Protocol\Relay;
  50 use Friendica\Util\DateTimeFormat;
  51 use Friendica\Util\HTTPSignature;
  52 use Friendica\Util\JsonLD;
  53 use Friendica\Util\Network;
  54 use Friendica\Util\Strings;
  55
  56 /**
  57  * ActivityPub Processor Protocol class
  58  */
  59 class Processor
  60 {
  61         const CACHEKEY_FETCH_ACTIVITY = 'processor:fetchMissingActivity:';
  62         const CACHEKEY_JUST_FETCHED   = 'processor:isJustFetched:';
  63
  64         /**
  65          * Add an object id to the list of processed ids
  66          *
  67          * @param string $id
  68          *
  69          * @return void
  70          */
  71         private static function addActivityId(string $id)
  72         {
  73                 DBA::delete('fetched-activity', ["`received` < ?", DateTimeFormat::utc('now - 5 minutes')]);
  74                 DBA::insert('fetched-activity', ['object-id' => $id, 'received' => DateTimeFormat::utcNow()]);
  75         }
  76
  77         /**
  78          * Checks if the given object id has just been fetched
  79          *
  80          * @param string $id
  81          *
  82          * @return boolean
  83          */
  84         private static function isFetched(string $id): bool
  85         {
  86                 return DBA::exists('fetched-activity', ['object-id' => $id]);
  87         }
  88
  89         /**
  90          * Extracts the tag character (#, @, !) from mention links
  91          *
  92          * @param string $body
  93          * @return string
  94          */
  95         public static function normalizeMentionLinks(string $body): string
  96         {
  97                 $body = preg_replace('%\[url=([^\[\]]*)]([#@!])(.*?)\[/url]%ism', '$2[url=$1]$3[/url]', $body);
  98                 $body = preg_replace('%([#@!])\[zrl=([^\[\]]*)](.*?)\[/zrl]%ism', '$1[url=$2]$3[/url]', $body);
  99                 return $body;
 100         }
 101
 102         /**
 103          * Convert the language array into a language JSON
 104          *
 105          * @param array $languages
 106          * @return string language JSON
 107          */
 108         private static function processLanguages(array $languages): string
 109         {
 110                 $codes = array_keys($languages);
 111                 $lang = [];
 112                 foreach ($codes as $code) {
 113                         $lang[$code] = 1;
 114                 }
 115
 116                 if (empty($lang)) {
 117                         return '';
 118                 }
 119
 120                 return json_encode($lang);
 121         }
 122         /**
 123          * Replaces emojis in the body
 124          *
 125          * @param int $uri_id
 126          * @param string $body
 127          * @param array $emojis
 128          *
 129          * @return string with replaced emojis
 130          */
 131         private static function replaceEmojis(int $uri_id, string $body, array $emojis): string
 132         {
 133                 $body = strtr($body,
 134                         array_combine(
 135                                 array_column($emojis, 'name'),
 136                                 array_map(function ($emoji) {
 137                                         return '[emoji=' . $emoji['href'] . ']' . $emoji['name'] . '[/emoji]';
 138                                 }, $emojis)
 139                         )
 140                 );
 141
 142                 // We store the emoji here to be able to avoid storing it in the media
 143                 foreach ($emojis as $emoji) {
 144                         Post\Link::getByLink($uri_id, $emoji['href']);
 145                 }
 146                 return $body;
 147         }
 148
 149         /**
 150          * Store attached media files in the post-media table
 151          *
 152          * @param int $uriid
 153          * @param array $attachment
 154          * @return void
 155          */
 156         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
 157         {
 158                 if (empty($attachment['url'])) {
 159                         return;
 160                 }
 161
 162                 $data = ['uri-id' => $uriid];
 163                 $data['type'] = Post\Media::UNKNOWN;
 164                 $data['url'] = $attachment['url'];
 165                 $data['mimetype'] = $attachment['mediaType'] ?? null;
 166                 $data['height'] = $attachment['height'] ?? null;
 167                 $data['width'] = $attachment['width'] ?? null;
 168                 $data['size'] = $attachment['size'] ?? null;
 169                 $data['preview'] = $attachment['image'] ?? null;
 170                 $data['description'] = $attachment['name'] ?? null;
 171
 172                 Post\Media::insert($data);
 173         }
 174
 175         /**
 176          * Store attachment data
 177          *
 178          * @param array   $activity
 179          * @param array   $item
 180          */
 181         private static function storeAttachments(array $activity, array $item)
 182         {
 183                 if (empty($activity['attachments'])) {
 184                         return;
 185                 }
 186
 187                 foreach ($activity['attachments'] as $attach) {
 188                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 189                 }
 190         }
 191
 192         /**
 193          * Store question data
 194          *
 195          * @param array   $activity
 196          * @param array   $item
 197          */
 198         private static function storeQuestion(array $activity, array $item)
 199         {
 200                 if (empty($activity['question'])) {
 201                         return;
 202                 }
 203                 $question = ['multiple' => $activity['question']['multiple']];
 204
 205                 if (!empty($activity['question']['voters'])) {
 206                         $question['voters'] = $activity['question']['voters'];
 207                 }
 208
 209                 if (!empty($activity['question']['end-time'])) {
 210                         $question['end-time'] = DateTimeFormat::utc($activity['question']['end-time']);
 211                 }
 212
 213                 Post\Question::update($item['uri-id'], $question);
 214
 215                 foreach ($activity['question']['options'] as $key => $option) {
 216                         $option = ['name' => $option['name'], 'replies' => $option['replies']];
 217                         Post\QuestionOption::update($item['uri-id'], $key, $option);
 218                 }
 219
 220                 Logger::debug('Storing incoming question', ['type' => $activity['type'], 'uri-id' => $item['uri-id'], 'question' => $activity['question']]);
 221         }
 222
 223         /**
 224          * Updates a message
 225          *
 226          * @param array      $activity   Activity array
 227          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 228          * @throws \ImagickException
 229          */
 230         public static function updateItem(array $activity)
 231         {
 232                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type', 'private'], ['uri' => $activity['id']]);
 233                 if (!DBA::isResult($item)) {
 234                         Logger::notice('No existing item, item will be created', ['uri' => $activity['id']]);
 235                         $item = self::createItem($activity, false);
 236                         if (empty($item)) {
 237                                 Queue::remove($activity);
 238                                 return;
 239                         }
 240
 241                         self::postItem($activity, $item);
 242                         return;
 243                 }
 244
 245                 $item['changed'] = DateTimeFormat::utcNow();
 246                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 247
 248                 Post\Media::deleteByURIId($item['uri-id'], [Post\Media::AUDIO, Post\Media::VIDEO, Post\Media::IMAGE, Post\Media::HTML]);
 249                 $item = self::processContent($activity, $item);
 250                 if (empty($item)) {
 251                         Queue::remove($activity);
 252                         return;
 253                 }
 254
 255                 self::storeAttachments($activity, $item);
 256                 self::storeQuestion($activity, $item);
 257
 258                 Post\History::add($item['uri-id'], $item);
 259                 Item::update($item, ['uri' => $activity['id']]);
 260
 261                 Queue::remove($activity);
 262
 263                 if ($activity['object_type'] == 'as:Event') {
 264                         $posts = Post::select(['event-id', 'uid'], ["`uri` = ? AND `event-id` > ?", $activity['id'], 0]);
 265                         while ($post = DBA::fetch($posts)) {
 266                                 self::updateEvent($post['event-id'], $activity);
 267                         }
 268                 }
 269         }
 270
 271         /**
 272          * Update an existing event
 273          *
 274          * @param int $event_id
 275          * @param array $activity
 276          */
 277         private static function updateEvent(int $event_id, array $activity)
 278         {
 279                 $event = DBA::selectFirst('event', [], ['id' => $event_id]);
 280
 281                 $event['edited']   = DateTimeFormat::utc($activity['updated']);
 282                 $event['summary']  = HTML::toBBCode($activity['name']);
 283                 $event['desc']     = HTML::toBBCode($activity['content']);
 284                 if (!empty($activity['start-time'])) {
 285                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 286                 }
 287                 if (!empty($activity['end-time'])) {
 288                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 289                 }
 290                 $event['nofinish'] = empty($event['finish']);
 291                 $event['location'] = $activity['location'];
 292
 293                 Logger::info('Updating event', ['uri' => $activity['id'], 'id' => $event_id]);
 294                 Event::store($event);
 295         }
 296
 297         /**
 298          * Prepares data for a message
 299          *
 300          * @param array $activity      Activity array
 301          * @param bool  $fetch_parents
 302          *
 303          * @return array Internal item
 304          *
 305          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 306          * @throws \ImagickException
 307          */
 308         public static function createItem(array $activity, bool $fetch_parents): array
 309         {
 310                 $item = [];
 311                 $item['verb'] = Activity::POST;
 312                 $item['thr-parent'] = $activity['reply-to-id'];
 313
 314                 if ($activity['reply-to-id'] == $activity['id']) {
 315                         $item['gravity'] = Item::GRAVITY_PARENT;
 316                         $item['object-type'] = Activity\ObjectType::NOTE;
 317                 } else {
 318                         $item['gravity'] = Item::GRAVITY_COMMENT;
 319                         $item['object-type'] = Activity\ObjectType::COMMENT;
 320                 }
 321
 322                 if (!empty($activity['conversation'])) {
 323                         $item['conversation'] = $activity['conversation'];
 324                 } elseif (!empty($activity['context'])) {
 325                         $item['conversation'] = $activity['context'];
 326                 }
 327
 328                 if (!empty($item['conversation'])) {
 329                         $conversation = Post::selectFirstThread(['uri'], ['conversation' => $item['conversation']]);
 330                         if (!empty($conversation)) {
 331                                 Logger::debug('Got conversation', ['conversation' => $item['conversation'], 'parent' => $conversation]);
 332                                 $item['parent-uri'] = $conversation['uri'];
 333                                 $item['parent-uri-id'] = ItemURI::getIdByURI($item['parent-uri']);
 334                         }
 335                 } else {
 336                         $conversation = [];
 337                 }
 338
 339                 Logger::debug('Create Item', ['id' => $activity['id'], 'conversation' => $item['conversation'] ?? '']);
 340                 if (empty($activity['author']) && empty($activity['actor'])) {
 341                         Logger::notice('Missing author and actor. We quit here.', ['activity' => $activity]);
 342                         Queue::remove($activity);
 343                         return [];
 344                 }
 345
 346                 if (!in_array(0, $activity['receiver']) || !DI::config()->get('system', 'fetch_parents')) {
 347                         $fetch_parents = false;
 348                 }
 349
 350                 if ($fetch_parents && empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 351                         $result = self::fetchParent($activity, !empty($conversation));
 352                         if (!empty($result)) {
 353                                 if (($item['thr-parent'] != $result) && Post::exists(['uri' => $result])) {
 354                                         $item['thr-parent'] = $result;
 355                                 }
 356                         } elseif (empty($conversation)) {
 357                                 return [];
 358                         }
 359                 }
 360
 361                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 362
 363                 if (empty($conversation) && empty($activity['directmessage']) && ($item['gravity'] != Item::GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 364                         Logger::notice('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 365                         if (!$fetch_parents) {
 366                                 Queue::remove($activity);
 367                         }
 368                         return [];
 369                 }
 370
 371                 $item['network'] = Protocol::ACTIVITYPUB;
 372                 $item['author-link'] = $activity['author'];
 373                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 374                 $item['owner-link'] = $activity['actor'];
 375                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 376
 377                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 378                         $item['private'] = Item::UNLISTED;
 379                 } elseif (in_array(0, $activity['receiver'])) {
 380                         $item['private'] = Item::PUBLIC;
 381                 } else {
 382                         $item['private'] = Item::PRIVATE;
 383                 }
 384
 385                 if (!empty($activity['raw'])) {
 386                         $item['source'] = $activity['raw'];
 387                 }
 388
 389                 $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 390
 391                 if (isset($activity['push'])) {
 392                         $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 393                 }
 394
 395                 if (!empty($activity['from-relay'])) {
 396                         $item['direction'] = Conversation::RELAY;
 397                 }
 398
 399                 if ($activity['object_type'] == 'as:Article') {
 400                         $item['post-type'] = Item::PT_ARTICLE;
 401                 } elseif ($activity['object_type'] == 'as:Audio') {
 402                         $item['post-type'] = Item::PT_AUDIO;
 403                 } elseif ($activity['object_type'] == 'as:Document') {
 404                         $item['post-type'] = Item::PT_DOCUMENT;
 405                 } elseif ($activity['object_type'] == 'as:Event') {
 406                         $item['post-type'] = Item::PT_EVENT;
 407                 } elseif ($activity['object_type'] == 'as:Image') {
 408                         $item['post-type'] = Item::PT_IMAGE;
 409                 } elseif ($activity['object_type'] == 'as:Page') {
 410                         $item['post-type'] = Item::PT_PAGE;
 411                 } elseif ($activity['object_type'] == 'as:Question') {
 412                         $item['post-type'] = Item::PT_POLL;
 413                 } elseif ($activity['object_type'] == 'as:Video') {
 414                         $item['post-type'] = Item::PT_VIDEO;
 415                 } else {
 416                         $item['post-type'] = Item::PT_NOTE;
 417                 }
 418
 419                 $item['isGroup'] = false;
 420
 421                 if (!empty($activity['thread-completion'])) {
 422                         if ($activity['thread-completion'] != $item['owner-id']) {
 423                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 424                                 $item['causer-link'] = $actor['url'];
 425                                 $item['causer-id']   = $activity['thread-completion'];
 426                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 427                         } else {
 428                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 429                                 $item['causer-link'] = $item['owner-link'];
 430                                 $item['causer-id']   = $item['owner-id'];
 431                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 432                         }
 433
 434                         $item['owner-link'] = $item['author-link'];
 435                         $item['owner-id']   = $item['author-id'];
 436                 }
 437
 438                 if (!$item['isGroup'] && !empty($activity['receiver_urls']['as:audience'])) {
 439                         foreach ($activity['receiver_urls']['as:audience'] as $audience) {
 440                                 $actor = APContact::getByURL($audience, false);
 441                                 if (($actor['type'] ?? 'Person') == 'Group') {
 442                                         Logger::debug('Group post detected via audience.', ['audience' => $audience, 'actor' => $activity['actor'], 'author' => $activity['author']]);
 443                                         $item['isGroup']    = true;
 444                                         $item['group-link'] = $item['owner-link'] = $audience;
 445                                         $item['owner-id']   = Contact::getIdForURL($audience);
 446                                         break;
 447                                 }
 448                         }
 449                 } else {
 450                         $owner = APContact::getByURL($item['owner-link'], false);
 451                 }
 452
 453                 if (!$item['isGroup'] && (($owner['type'] ?? 'Person') == 'Group')) {
 454                         Logger::debug('Group post detected via owner.', ['actor' => $activity['actor'], 'author' => $activity['author']]);
 455                         $item['isGroup']    = true;
 456                         $item['group-link'] = $item['owner-link'];
 457                 } elseif (!empty($item['causer-link'])) {
 458                         $causer = APContact::getByURL($item['causer-link'], false);
 459                 }
 460
 461                 if (!$item['isGroup'] && (($causer['type'] ?? 'Person') == 'Group')) {
 462                         Logger::debug('Group post detected via causer.', ['actor' => $activity['actor'], 'author' => $activity['author'], 'causer' => $item['causer-link']]);
 463                         $item['isGroup']    = true;
 464                         $item['group-link'] = $item['causer-link'];
 465                 }
 466
 467                 if (!empty($item['group-link']) && empty($item['causer-link'])) {
 468                         $item['causer-link'] = $item['group-link'];
 469                         $item['causer-id']   = Contact::getIdForURL($item['causer-link']);
 470                 }
 471
 472                 $item['uri'] = $activity['id'];
 473
 474                 if (empty($activity['published']) || empty($activity['updated'])) {
 475                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 476                 }
 477
 478                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 479                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 480                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 481                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 482
 483                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 484                 if (empty($item['uri-id'])) {
 485                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 486                         return [];
 487                 }
 488
 489                 $item['thr-parent-id'] = ItemURI::getIdByURI($item['thr-parent']);
 490
 491                 $item = self::processContent($activity, $item);
 492                 if (empty($item)) {
 493                         Logger::info('Message was not processed');
 494                         Queue::remove($activity);
 495                         return [];
 496                 }
 497
 498                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 499
 500                 self::storeAttachments($activity, $item);
 501                 self::storeQuestion($activity, $item);
 502
 503                 // We received the post via AP, so we set the protocol of the server to AP
 504                 $contact = Contact::getById($item['author-id'], ['gsid']);
 505                 if (!empty($contact['gsid'])) {
 506                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 507                 }
 508
 509                 if ($item['author-id'] != $item['owner-id']) {
 510                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 511                         if (!empty($contact['gsid'])) {
 512                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 513                         }
 514                 }
 515
 516                 return $item;
 517         }
 518
 519         /**
 520          * Fetch and process parent posts for the given activity
 521          *
 522          * @param array $activity
 523          * @param bool  $in_background
 524          *
 525          * @return string
 526          */
 527         private static function fetchParent(array $activity, bool $in_background = false): string
 528         {
 529                 if (self::isFetched($activity['reply-to-id'])) {
 530                         Logger::info('Id is already fetched', ['id' => $activity['reply-to-id']]);
 531                         return '';
 532                 }
 533
 534                 self::addActivityId($activity['reply-to-id']);
 535
 536                 if (!DI::config()->get('system', 'fetch_by_worker')) {
 537                         $in_background = false;
 538                 }
 539
 540                 $recursion_depth = $activity['recursion-depth'] ?? 0;
 541
 542                 if (!$in_background && ($recursion_depth < DI::config()->get('system', 'max_recursion_depth'))) {
 543                         Logger::info('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 544                         $result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 545                         if (empty($result) && self::isActivityGone($activity['reply-to-id'])) {
 546                                 Logger::notice('The activity is gone, the queue entry will be deleted', ['parent' => $activity['reply-to-id']]);
 547                                 if (!empty($activity['entry-id'])) {
 548                                         Queue::deleteById($activity['entry-id']);
 549                                 }
 550                                 return '';
 551                         } elseif (!empty($result)) {
 552                                 $exists = Post::exists(['uri' => [$result, $activity['reply-to-id']]]);
 553                                 if ($exists) {
 554                                         Logger::info('The activity has been fetched and created.', ['parent' => $result]);
 555                                         return $result;
 556                                 } elseif (DI::config()->get('system', 'fetch_by_worker') || DI::config()->get('system', 'decoupled_receiver')) {
 557                                         Logger::info('The activity has been fetched and will hopefully be created later.', ['parent' => $result]);
 558                                 } else {
 559                                         Logger::notice('The activity exists but has not been created, the queue entry will be deleted.', ['parent' => $result]);
 560                                         if (!empty($activity['entry-id'])) {
 561                                                 Queue::deleteById($activity['entry-id']);
 562                                         }
 563                                 }
 564                                 return '';
 565                         }
 566                         if (empty($result) && !DI::config()->get('system', 'fetch_by_worker')) {
 567                                 return '';
 568                         }
 569                 } elseif (self::isActivityGone($activity['reply-to-id'])) {
 570                         Logger::notice('The activity is gone. We will not spawn a worker. The queue entry will be deleted', ['parent' => $activity['reply-to-id']]);
 571                         if ($in_background) {
 572                                 // fetching in background is done for all activities where we have got the conversation
 573                                 // There we only delete the single activity and not the whole thread since we can store the
 574                                 // other posts in the thread even with missing posts.
 575                                 Queue::remove($activity);
 576                         } elseif (!empty($activity['entry-id'])) {
 577                                 Queue::deleteById($activity['entry-id']);
 578                         }
 579                         return '';
 580                 } elseif ($in_background) {
 581                         Logger::notice('Fetching is done in the background.', ['parent' => $activity['reply-to-id']]);
 582                 } else {
 583                         Logger::notice('Recursion level is too high.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 584                 }
 585
 586                 if (!Fetch::hasWorker($activity['reply-to-id'])) {
 587                         Logger::notice('Fetching is done by worker.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 588                         Fetch::add($activity['reply-to-id']);
 589                         $activity['recursion-depth'] = 0;
 590                         $wid = Worker::add(Worker::PRIORITY_HIGH, 'FetchMissingActivity', $activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 591                         Fetch::setWorkerId($activity['reply-to-id'], $wid);
 592                 } else {
 593                         Logger::debug('Activity will already be fetched via a worker.', ['url' => $activity['reply-to-id']]);
 594                 }
 595
 596                 return '';
 597         }
 598
 599         /**
 600          * Check if a given activity is no longer available
 601          *
 602          * @param string $url
 603          *
 604          * @return boolean
 605          */
 606         public static function isActivityGone(string $url): bool
 607         {
 608                 try {
 609                         $curlResult = HTTPSignature::fetchRaw($url, 0);
 610                 } catch (\Exception $exception) {
 611                         Logger::notice('Error fetching url', ['url' => $url, 'exception' => $exception]);
 612                         return true;
 613                 }
 614
 615                 if (Network::isUrlBlocked($url)) {
 616                         return true;
 617                 }
 618
 619                 // @todo To ensure that the remote system is working correctly, we can check if the "Content-Type" contains JSON
 620                 if (in_array($curlResult->getReturnCode(), [401, 404])) {
 621                         return true;
 622                 }
 623
 624                 if ($curlResult->isSuccess()) {
 625                         $object = json_decode($curlResult->getBody(), true);
 626                         if (!empty($object)) {
 627                                 $activity = JsonLD::compact($object);
 628                                 if (JsonLD::fetchElement($activity, '@type') == 'as:Tombstone') {
 629                                         return true;
 630                                 }
 631                         }
 632                 } elseif ($curlResult->getReturnCode() == 0) {
 633                         $host = parse_url($url, PHP_URL_HOST);
 634                         if (!(filter_var($host, FILTER_VALIDATE_IP) || @dns_get_record($host . '.', DNS_A + DNS_AAAA))) {
 635                                 return true;
 636                         }
 637                 }
 638
 639                 return false;
 640         }
 641         /**
 642          * Delete items
 643          *
 644          * @param array $activity
 645          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 646          * @throws \ImagickException
 647          */
 648         public static function deleteItem(array $activity)
 649         {
 650                 $owner = Contact::getIdForURL($activity['actor']);
 651
 652                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 653                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 654                 Queue::remove($activity);
 655         }
 656
 657         /**
 658          * Prepare the item array for an activity
 659          *
 660          * @param array $activity Activity array
 661          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 662          * @throws \ImagickException
 663          */
 664         public static function addTag(array $activity)
 665         {
 666                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 667                         return;
 668                 }
 669
 670                 foreach ($activity['receiver'] as $receiver) {
 671                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 672                         if (!DBA::isResult($item)) {
 673                                 // We don't fetch missing content for this purpose
 674                                 continue;
 675                         }
 676
 677                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 678                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 679                                 continue;
 680                         }
 681
 682                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 683                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 684                 }
 685         }
 686
 687         /**
 688          * Prepare the item array for an activity
 689          *
 690          * @param array      $activity   Activity array
 691          * @param string     $verb       Activity verb
 692          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 693          * @throws \ImagickException
 694          */
 695         public static function createActivity(array $activity, string $verb)
 696         {
 697                 $activity['reply-to-id'] = $activity['object_id'];
 698                 $item = self::createItem($activity, false);
 699                 if (empty($item)) {
 700                         Logger::debug('Activity was not prepared', ['id' => $activity['object_id']]);
 701                         return;
 702                 }
 703
 704                 $item['verb'] = $verb;
 705                 $item['thr-parent'] = $activity['object_id'];
 706                 $item['gravity'] = Item::GRAVITY_ACTIVITY;
 707                 unset($item['post-type']);
 708                 $item['object-type'] = Activity\ObjectType::NOTE;
 709
 710                 if (!empty($activity['content'])) {
 711                         $item['body'] = HTML::toBBCode($activity['content']);
 712                 }
 713
 714                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 715
 716                 self::postItem($activity, $item);
 717         }
 718
 719         /**
 720          * Fetch the Uri-Id of a post for the "featured" collection
 721          *
 722          * @param array $activity
 723          * @return null|array
 724          */
 725         private static function getUriIdForFeaturedCollection(array $activity)
 726         {
 727                 $actor = APContact::getByURL($activity['actor']);
 728                 if (empty($actor)) {
 729                         return null;
 730                 }
 731
 732                 // Refetch the account when the "featured" collection is missing.
 733                 // This can be removed in a future version (end of 2022 should be good).
 734                 if (empty($actor['featured'])) {
 735                         $actor = APContact::getByURL($activity['actor'], true);
 736                         if (empty($actor)) {
 737                                 return null;
 738                         }
 739                 }
 740
 741                 $parent = Post::selectFirst(['uri-id', 'author-id'], ['uri' => $activity['object_id']]);
 742                 if (empty($parent['uri-id'])) {
 743                         if (self::fetchMissingActivity($activity['object_id'], $activity, '', Receiver::COMPLETION_AUTO)) {
 744                                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 745                         }
 746                 }
 747
 748                 if (!empty($parent['uri-id'])) {
 749                         $parent;
 750                 }
 751
 752                 return null;
 753         }
 754
 755         /**
 756          * Add a post to the "Featured" collection
 757          *
 758          * @param array $activity
 759          */
 760         public static function addToFeaturedCollection(array $activity)
 761         {
 762                 $post = self::getUriIdForFeaturedCollection($activity);
 763                 if (empty($post)) {
 764                         return;
 765                 }
 766
 767                 Logger::debug('Add post to featured collection', ['post' => $post]);
 768
 769                 Post\Collection::add($post['uri-id'], Post\Collection::FEATURED, $post['author-id']);
 770                 Queue::remove($activity);
 771         }
 772
 773         /**
 774          * Remove a post to the "Featured" collection
 775          *
 776          * @param array $activity
 777          */
 778         public static function removeFromFeaturedCollection(array $activity)
 779         {
 780                 $post = self::getUriIdForFeaturedCollection($activity);
 781                 if (empty($post)) {
 782                         return;
 783                 }
 784
 785                 Logger::debug('Remove post from featured collection', ['post' => $post]);
 786
 787                 Post\Collection::remove($post['uri-id'], Post\Collection::FEATURED);
 788                 Queue::remove($activity);
 789         }
 790
 791         /**
 792          * Create an event
 793          *
 794          * @param array $activity Activity array
 795          * @param array $item
 796          *
 797          * @return int event id
 798          * @throws \Exception
 799          */
 800         public static function createEvent(array $activity, array $item): int
 801         {
 802                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 803                 $event['desc']      = HTML::toBBCode($activity['content'] ?? '');
 804                 if (!empty($activity['start-time'])) {
 805                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 806                 }
 807                 if (!empty($activity['end-time'])) {
 808                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 809                 }
 810                 $event['nofinish']  = empty($event['finish']);
 811                 $event['location']  = $activity['location'];
 812                 $event['cid']       = $item['contact-id'];
 813                 $event['uid']       = $item['uid'];
 814                 $event['uri']       = $item['uri'];
 815                 $event['edited']    = $item['edited'];
 816                 $event['private']   = $item['private'];
 817                 $event['guid']      = $item['guid'];
 818                 $event['plink']     = $item['plink'];
 819                 $event['network']   = $item['network'];
 820                 $event['protocol']  = $item['protocol'];
 821                 $event['direction'] = $item['direction'];
 822                 $event['source']    = $item['source'];
 823
 824                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 825                 if (DBA::isResult($ev)) {
 826                         $event['id'] = $ev['id'];
 827                 }
 828
 829                 $event_id = Event::store($event);
 830
 831                 Logger::info('Event was stored', ['id' => $event_id]);
 832
 833                 return $event_id;
 834         }
 835
 836         /**
 837          * Process the content
 838          *
 839          * @param array $activity Activity array
 840          * @param array $item
 841          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 842          * @throws \Exception
 843          */
 844         private static function processContent(array $activity, array $item)
 845         {
 846                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 847                         $item['title'] = strip_tags($activity['name'] ?? '');
 848                         $content = Markdown::toBBCode($activity['content']);
 849                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 850                         $item['title'] = $activity['name'];
 851                         $content = $activity['content'];
 852                 } else {
 853                         // By default assume "text/html"
 854                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 855                         $content = HTML::toBBCode($activity['content'] ?? '');
 856                 }
 857
 858                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 859
 860                 if (!empty($activity['languages'])) {
 861                         $item['language'] = self::processLanguages($activity['languages']);
 862                 }
 863
 864                 if (!empty($activity['emojis'])) {
 865                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 866                 }
 867
 868                 $content = self::addMentionLinks($content, $activity['tags']);
 869
 870                 if (!empty($activity['quote-url'])) {
 871                         $id = Item::fetchByLink($activity['quote-url']);
 872                         if ($id) {
 873                                 $shared_item = Post::selectFirst(['uri-id'], ['id' => $id]);
 874                                 $item['quote-uri-id'] = $shared_item['uri-id'];
 875                         } elseif ($uri_id = ItemURI::getIdByURI($activity['quote-url'], false)) {
 876                                 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]);
 877                                 $item['quote-uri-id'] = $uri_id;
 878                         } else {
 879                                 Logger::info('Quote was not fetched', ['guid' => $item['guid'], 'uri-id' => $item['uri-id'], 'quote' => $activity['quote-url']]);
 880                         }
 881                 }
 882
 883                 if (!empty($activity['source'])) {
 884                         $item['body'] = $activity['source'];
 885                         $item['raw-body'] = $content;
 886
 887                         $quote_uri_id = Item::getQuoteUriId($item['body']);
 888                         if (empty($item['quote-uri-id']) && !empty($quote_uri_id)) {
 889                                 $item['quote-uri-id'] = $quote_uri_id;
 890                         }
 891
 892                         $item['body'] = BBCode::removeSharedData($item['body']);
 893                 } else {
 894                         $parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
 895                         if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == Item::GRAVITY_COMMENT)) {
 896                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 897                                 if (!DBA::isResult($parent)) {
 898                                         Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
 899                                         return false;
 900                                 }
 901                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 902                         }
 903                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 904                         $item['raw-body'] = $item['body'] = $content;
 905                 }
 906
 907                 if (!empty($item['author-id']) && ($item['author-id'] == $item['owner-id'])) {
 908                         foreach (Tag::getFromBody($item['body'], Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION]) as $tag) {
 909                                 $actor = APContact::getByURL($tag[2], false);
 910                                 if (($actor['type'] ?? 'Person') == 'Group') {
 911                                         Logger::debug('Group post detected via exclusive mention.', ['mention' => $actor['url'], 'actor' => $activity['actor'], 'author' => $activity['author']]);
 912                                         $item['isGroup']    = true;
 913                                         $item['group-link'] = $item['owner-link'] = $actor['url'];
 914                                         $item['owner-id']   = Contact::getIdForURL($actor['url']);
 915                                         break;
 916                                 }
 917                         }
 918                 }
 919
 920                 self::storeFromBody($item);
 921                 self::storeTags($item['uri-id'], $activity['tags']);
 922
 923                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 924
 925                 $item['location'] = $activity['location'];
 926
 927                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 928                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 929                 }
 930
 931                 $item['app'] = $activity['generator'];
 932
 933                 return $item;
 934         }
 935
 936         /**
 937          * Store hashtags and mentions
 938          *
 939          * @param array $item
 940          */
 941         private static function storeFromBody(array $item)
 942         {
 943                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 944                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 945
 946                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 947         }
 948
 949         /**
 950          * Generate a GUID out of an URL of an ActivityPub post.
 951          *
 952          * @param string $url message URL
 953          * @return string with GUID
 954          */
 955         private static function getGUIDByURL(string $url): string
 956         {
 957                 $parsed = parse_url($url);
 958
 959                 $host_hash = hash('crc32', $parsed['host']);
 960
 961                 unset($parsed["scheme"]);
 962                 unset($parsed["host"]);
 963
 964                 $path = implode("/", $parsed);
 965
 966                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 967         }
 968
 969         /**
 970          * Checks if an incoming message is wanted
 971          *
 972          * @param array $activity
 973          * @param array $item
 974          * @return boolean Is the message wanted?
 975          */
 976         private static function isSolicitedMessage(array $activity, array $item): bool
 977         {
 978                 // The checks are split to improve the support when searching why a message was accepted.
 979                 if (count($activity['receiver']) != 1) {
 980                         // The message has more than one receiver, so it is wanted.
 981                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 982                         return true;
 983                 }
 984
 985                 if ($item['private'] == Item::PRIVATE) {
 986                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 987                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 988                         return true;
 989                 }
 990
 991                 if (!empty($activity['from-relay'])) {
 992                         // We check relay posts at another place. When it arrived here, the message is already checked.
 993                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 994                         return true;
 995                 }
 996
 997                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUNCE])) {
 998                         // Manual completions and completions caused by reshares are allowed without any further checks.
 999                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
1000                         return true;
1001                 }
1002
1003                 if ($item['gravity'] != Item::GRAVITY_PARENT) {
1004                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
1005                         // This can possibly be improved in the future.
1006                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
1007                         return true;
1008                 }
1009
1010                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
1011                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB, $activity['thread-completion'] ?? 0)) {
1012                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
1013                         return true;
1014                 } else {
1015                         return false;
1016                 }
1017         }
1018
1019         /**
1020          * Creates an item post
1021          *
1022          * @param array $activity Activity data
1023          * @param array $item     item array
1024          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1025          * @throws \ImagickException
1026          */
1027         public static function postItem(array $activity, array $item)
1028         {
1029                 if (empty($item)) {
1030                         return;
1031                 }
1032
1033                 $stored = false;
1034                 $success = false;
1035                 ksort($activity['receiver']);
1036
1037                 if (!self::isSolicitedMessage($activity, $item)) {
1038                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
1039                         if (!empty($activity['entry-id'])) {
1040                                 Queue::deleteById($activity['entry-id']);
1041                         }
1042                         return;
1043                 }
1044
1045                 foreach ($activity['receiver'] as $receiver) {
1046                         if ($receiver == -1) {
1047                                 continue;
1048                         }
1049
1050                         if (($receiver != 0) && empty($item['parent-uri-id']) && !empty($item['thr-parent-id'])) {
1051                                 $parent = Post::selectFirst(['parent-uri-id', 'parent-uri'], ['uri-id' => $item['thr-parent-id'], 'uid' => [0, $receiver]]);
1052                                 if (!empty($parent['parent-uri-id'])) {
1053                                         $item['parent-uri-id'] = $parent['parent-uri-id'];
1054                                         $item['parent-uri']    = $parent['parent-uri'];
1055                                 }
1056                         }
1057
1058                         $item['uid'] = $receiver;
1059
1060                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
1061                         switch($type) {
1062                                 case Receiver::TARGET_TO:
1063                                         $item['post-reason'] = Item::PR_TO;
1064                                         break;
1065                                 case Receiver::TARGET_CC:
1066                                         $item['post-reason'] = Item::PR_CC;
1067                                         break;
1068                                 case Receiver::TARGET_BTO:
1069                                         $item['post-reason'] = Item::PR_BTO;
1070                                         break;
1071                                 case Receiver::TARGET_BCC:
1072                                         $item['post-reason'] = Item::PR_BCC;
1073                                         break;
1074                                 case Receiver::TARGET_AUDIENCE:
1075                                         $item['post-reason'] = Item::PR_AUDIENCE;
1076                                         break;
1077                                 case Receiver::TARGET_FOLLOWER:
1078                                         $item['post-reason'] = Item::PR_FOLLOWER;
1079                                         break;
1080                                 case Receiver::TARGET_ANSWER:
1081                                         $item['post-reason'] = Item::PR_COMMENT;
1082                                         break;
1083                                 case Receiver::TARGET_GLOBAL:
1084                                         $item['post-reason'] = Item::PR_GLOBAL;
1085                                         break;
1086                                 default:
1087                                         $item['post-reason'] = Item::PR_NONE;
1088                         }
1089
1090                         $item['post-reason'] = Item::getPostReason($item);
1091
1092                         if (in_array($item['post-reason'], [Item::PR_GLOBAL, Item::PR_NONE])) {
1093                                 if (!empty($activity['from-relay'])) {
1094                                         $item['post-reason'] = Item::PR_RELAY;
1095                                 } elseif (!empty($activity['thread-completion'])) {
1096                                         $item['post-reason'] = Item::PR_FETCHED;
1097                                 } elseif (!empty($activity['push'])) {
1098                                         $item['post-reason'] = Item::PR_PUSHED;
1099                                 }
1100                         } elseif (($item['post-reason'] == Item::PR_FOLLOWER) && !empty($activity['from-relay'])) {
1101                                 // When a post arrives via a relay and we follow the author, we have to override the causer.
1102                                 // Otherwise the system assumes that we follow the relay. (See "addRowInformation")
1103                                 Logger::debug('Relay post for follower', ['receiver' => $receiver, 'guid' => $item['guid'], 'relay' => $activity['from-relay']]);
1104                                 $item['causer-id'] = ($item['gravity'] == Item::GRAVITY_PARENT) ? $item['owner-id'] : $item['author-id'];
1105                         }
1106
1107                         if ($item['isGroup']) {
1108                                 $item['contact-id'] = Contact::getIdForURL($item['group-link'], $receiver);
1109                         } else {
1110                                 $item['contact-id'] = Contact::getIdForURL($item['author-link'], $receiver);
1111                         }
1112
1113                         if (($receiver != 0) && empty($item['contact-id'])) {
1114                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
1115                         }
1116
1117                         if (!empty($activity['directmessage'])) {
1118                                 self::postMail($activity, $item);
1119                                 continue;
1120                         }
1121
1122                         if (($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])) {
1123                                 if (!$item['isGroup']) {
1124                                         if ($item['post-reason'] == Item::PR_BCC) {
1125                                                 Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id'], 'url' => $item['uri']]);
1126                                                 continue;
1127                                         }
1128
1129                                         if ((DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE)
1130                                                 && in_array($activity['thread-children-type'] ?? '', Receiver::ACTIVITY_TYPES)) {
1131                                                 Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
1132                                                         ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
1133                                                 continue;
1134                                         }
1135                                 }
1136
1137                                 $isGroup = false;
1138                                 $user = User::getById($receiver, ['account-type']);
1139                                 if (!empty($user['account-type'])) {
1140                                         $isGroup = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
1141                                 }
1142
1143                                 if ((DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE)
1144                                         && ((!$isGroup && !$item['isGroup'] && ($activity['type'] != 'as:Announce'))
1145                                         || !Contact::isSharingByURL($activity['actor'], $receiver))) {
1146                                         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']]);
1147                                         continue;
1148                                 }
1149
1150                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
1151                         }
1152
1153                         if (!self::hasParents($item, $receiver)) {
1154                                 continue;
1155                         }
1156
1157                         if (($item['gravity'] != Item::GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
1158                                 $event_id = self::createEvent($activity, $item);
1159
1160                                 $item = Event::getItemArrayForImportedId($event_id, $item);
1161                         }
1162
1163                         $item_id = Item::insert($item);
1164                         if ($item_id) {
1165                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
1166                                 $success = true;
1167                         } else {
1168                                 Logger::notice('Item insertion aborted', ['uri' => $item['uri'], 'uid' => $item['uid']]);
1169                                 if (($item['uid'] == 0) && (count($activity['receiver']) > 1)) {
1170                                         Logger::info('Public item was aborted. We skip for all users.', ['uri' => $item['uri']]);
1171                                         break;
1172                                 }
1173                         }
1174
1175                         if ($item['uid'] == 0) {
1176                                 $stored = $item_id;
1177                         }
1178                 }
1179
1180                 Queue::remove($activity);
1181
1182                 if ($success && Queue::hasChildren($item['uri']) && Post::exists(['uri' => $item['uri']])) {
1183                         Queue::processReplyByUri($item['uri']);
1184                 }
1185
1186                 // Store send a follow request for every reshare - but only when the item had been stored
1187                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == Item::GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
1188                         $author = APContact::getByURL($item['owner-link'], false);
1189                         // We send automatic follow requests for reshared messages. (We don't need though for group posts)
1190                         if ($author['type'] != 'Group') {
1191                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
1192                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
1193                         }
1194                 }
1195         }
1196
1197         /**
1198          * Checks if there are parent posts for the given receiver.
1199          * If not, then the system will try to add them.
1200          *
1201          * @param array $item
1202          * @param integer $receiver
1203          * @return boolean
1204          */
1205         private static function hasParents(array $item, int $receiver)
1206         {
1207                 if (($receiver == 0) || ($item['gravity'] == Item::GRAVITY_PARENT)) {
1208                         return true;
1209                 }
1210
1211                 $fields = ['causer-id' => $item['causer-id'] ?? $item['author-id'], 'post-reason' => Item::PR_FETCHED];
1212
1213                 $add_parent = true;
1214
1215                 if ($item['verb'] != Activity::ANNOUNCE) {
1216                         switch (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer')) {
1217                                 case Item::COMPLETION_COMMENT:
1218                                         $add_parent = ($item['gravity'] != Item::GRAVITY_ACTIVITY);
1219                                         break;
1220
1221                                 case Item::COMPLETION_NONE:
1222                                         $add_parent = false;
1223                                         break;
1224                         }
1225                 }
1226
1227                 if ($add_parent) {
1228                         $add_parent = Contact::isSharing($fields['causer-id'], $receiver);
1229                         if (!$add_parent && ($item['author-id'] != $fields['causer-id'])) {
1230                                 $add_parent = Contact::isSharing($item['author-id'], $receiver);
1231                         }
1232                         if (!$add_parent && !in_array($item['owner-id'], [$fields['causer-id'], $item['author-id']])) {
1233                                 $add_parent = Contact::isSharing($item['owner-id'], $receiver);
1234                         }
1235                 }
1236
1237                 $has_parents = false;
1238
1239                 if (!empty($item['parent-uri-id'])) {
1240                         if (Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => $receiver])) {
1241                                 $has_parents = true;
1242                         } elseif ($add_parent && Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => 0])) {
1243                                 $stored = Item::storeForUserByUriId($item['parent-uri-id'], $receiver, $fields);
1244                                 $has_parents = (bool)$stored;
1245                                 if ($stored) {
1246                                         Logger::notice('Inserted missing parent post', ['stored' => $stored, 'uid' => $receiver, 'parent' => $item['parent-uri']]);
1247                                 } else {
1248                                         Logger::notice('Parent could not be added.', ['uid' => $receiver, 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1249                                         return false;
1250                                 }
1251                         } elseif ($add_parent) {
1252                                 Logger::debug('Parent does not exist.', ['uid' => $receiver, 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1253                         } else {
1254                                 Logger::debug('Parent should not be added.', ['uid' => $receiver, 'gravity' => $item['gravity'], 'verb' => $item['verb'], 'guid' => $item['guid'], 'uri' => $item['uri'], 'parent' => $item['parent-uri']]);
1255                         }
1256                 }
1257
1258                 if (empty($item['parent-uri-id']) || ($item['thr-parent-id'] != $item['parent-uri-id'])) {
1259                         if (Post::exists(['uri-id' => $item['thr-parent-id'], 'uid' => $receiver])) {
1260                                 $has_parents = true;
1261                         } elseif (($has_parents || $add_parent) && Post::exists(['uri-id' => $item['thr-parent-id'], 'uid' => 0])) {
1262                                 $stored = Item::storeForUserByUriId($item['thr-parent-id'], $receiver, $fields);
1263                                 $has_parents = $has_parents || (bool)$stored;
1264                                 if ($stored) {
1265                                         Logger::notice('Inserted missing thread parent post', ['stored' => $stored, 'uid' => $receiver, 'thread-parent' => $item['thr-parent']]);
1266                                 } else {
1267                                         Logger::notice('Thread parent could not be added.', ['uid' => $receiver, 'uri' => $item['uri'], 'thread-parent' => $item['thr-parent']]);
1268                                 }
1269                         } elseif ($add_parent) {
1270                                 Logger::debug('Thread parent does not exist.', ['uid' => $receiver, 'uri' => $item['uri'], 'thread-parent' => $item['thr-parent']]);
1271                         } else {
1272                                 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']]);
1273                         }
1274                 }
1275
1276                 return $has_parents;
1277         }
1278
1279         /**
1280          * Store tags and mentions into the tag table
1281          *
1282          * @param integer $uriid
1283          * @param array $tags
1284          */
1285         private static function storeTags(int $uriid, array $tags = null)
1286         {
1287                 foreach ($tags as $tag) {
1288                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1289                                 continue;
1290                         }
1291
1292                         $hash = substr($tag['name'], 0, 1);
1293
1294                         if ($tag['type'] == 'Mention') {
1295                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
1296                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
1297                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
1298                                         $tag['name'] = substr($tag['name'], 1);
1299                                 }
1300                                 $type = Tag::IMPLICIT_MENTION;
1301
1302                                 if (!empty($tag['href'])) {
1303                                         $apcontact = APContact::getByURL($tag['href']);
1304                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
1305                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
1306                                         }
1307                                 }
1308                         } elseif ($tag['type'] == 'Hashtag') {
1309                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
1310                                         $tag['name'] = substr($tag['name'], 1);
1311                                 }
1312                                 $type = Tag::HASHTAG;
1313                         }
1314
1315                         if (empty($tag['name'])) {
1316                                 continue;
1317                         }
1318
1319                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
1320                 }
1321         }
1322
1323         public static function storeReceivers(int $uriid, array $receivers)
1324         {
1325                 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 => $type) {
1326                         if (!empty($receivers[$element])) {
1327                                 foreach ($receivers[$element] as $receiver) {
1328                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
1329                                                 $name = Receiver::PUBLIC_COLLECTION;
1330                                         } elseif ($path = parse_url($receiver, PHP_URL_PATH)) {
1331                                                 $name = trim($path, '/');
1332                                         } elseif ($host = parse_url($receiver, PHP_URL_HOST)) {
1333                                                 $name = $host;
1334                                         } else {
1335                                                 Logger::warning('Unable to coerce name from receiver', ['element' => $element, 'type' => $type, 'receiver' => $receiver]);
1336                                                 $name = '';
1337                                         }
1338
1339                                         $target = Tag::getTargetType($receiver);
1340                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
1341                                         Tag::store($uriid, $type, $name, $receiver, $target);
1342                                 }
1343                         }
1344                 }
1345         }
1346
1347         /**
1348          * Creates an mail post
1349          *
1350          * @param array $activity Activity data
1351          * @param array $item     item array
1352          * @return int|bool New mail table row id or false on error
1353          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1354          */
1355         private static function postMail(array $activity, array $item)
1356         {
1357                 if (($item['gravity'] != Item::GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
1358                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
1359                         return false;
1360                 }
1361
1362                 Logger::info('Direct Message', $item);
1363
1364                 $msg = [];
1365                 $msg['uid'] = $item['uid'];
1366
1367                 $msg['contact-id'] = $item['contact-id'];
1368
1369                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1370                 $msg['from-name'] = $contact['name'];
1371                 $msg['from-url'] = $contact['url'];
1372                 $msg['from-photo'] = $contact['photo'];
1373
1374                 $msg['uri'] = $item['uri'];
1375                 $msg['created'] = $item['created'];
1376
1377                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1378                 if (DBA::isResult($parent)) {
1379                         $msg['parent-uri'] = $parent['parent-uri'];
1380                         $msg['title'] = $parent['title'];
1381                 } else {
1382                         $msg['parent-uri'] = $item['thr-parent'];
1383
1384                         if (!empty($item['title'])) {
1385                                 $msg['title'] = $item['title'];
1386                         } elseif (!empty($item['content-warning'])) {
1387                                 $msg['title'] = $item['content-warning'];
1388                         } else {
1389                                 // Trying to generate a title out of the body
1390                                 $title = $item['body'];
1391
1392                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1393                                         $title = $matches[3];
1394                                 }
1395
1396                                 $title = trim(BBCode::toPlaintext($title));
1397
1398                                 if (strlen($title) > 20) {
1399                                         $title = substr($title, 0, 20) . '...';
1400                                 }
1401
1402                                 $msg['title'] = $title;
1403                         }
1404                 }
1405                 $msg['body'] = $item['body'];
1406
1407                 return Mail::insert($msg);
1408         }
1409
1410         /**
1411          * Fetch featured posts from a contact with the given url
1412          *
1413          * @param string $url
1414          * @return void
1415          */
1416         public static function fetchFeaturedPosts(string $url)
1417         {
1418                 Logger::info('Fetch featured posts', ['contact' => $url]);
1419
1420                 $apcontact = APContact::getByURL($url);
1421                 if (empty($apcontact['featured'])) {
1422                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1423                         return;
1424                 }
1425
1426                 $pcid = Contact::getIdForURL($url, 0, false);
1427                 if (empty($pcid)) {
1428                         Logger::notice('Contact not found', ['contact' => $url]);
1429                         return;
1430                 }
1431
1432                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1433                 if (!empty($posts)) {
1434                         $old_featured = array_column($posts, 'uri-id');
1435                 } else {
1436                         $old_featured = [];
1437                 }
1438
1439                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1440                 if (empty($featured)) {
1441                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1442
1443                         foreach ($old_featured as $uri_id) {
1444                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1445                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1446                         }
1447                         return;
1448                 }
1449
1450                 $new = 0;
1451                 $old = 0;
1452
1453                 foreach ($featured as $post) {
1454                         if (empty($post['id'])) {
1455                                 continue;
1456                         }
1457                         $id = Item::fetchByLink($post['id']);
1458                         if (!empty($id)) {
1459                                 $item = Post::selectFirst(['uri-id', 'featured', 'author-id'], ['id' => $id]);
1460                                 if (!empty($item['uri-id'])) {
1461                                         if (!$item['featured']) {
1462                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED, $item['author-id']);
1463                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1464                                                 $new++;
1465                                         } else {
1466                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1467                                                 $old++;
1468                                         }
1469
1470                                         $index = array_search($item['uri-id'], $old_featured);
1471                                         if (!($index === false)) {
1472                                                 unset($old_featured[$index]);
1473                                         }
1474                                 }
1475                         }
1476                 }
1477
1478                 foreach ($old_featured as $uri_id) {
1479                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1480                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1481                 }
1482
1483                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1484         }
1485
1486         public static function fetchCachedActivity(string $url, int $uid): array
1487         {
1488                 $cachekey = self::CACHEKEY_FETCH_ACTIVITY . $uid . ':' . hash('sha256', $url);
1489                 $object = DI::cache()->get($cachekey);
1490
1491                 if (!is_null($object)) {
1492                         if (!empty($object)) {
1493                                 Logger::debug('Fetch from cache', ['url' => $url, 'uid' => $uid]);
1494                         } else {
1495                                 Logger::debug('Fetch from negative cache', ['url' => $url, 'uid' => $uid]);
1496                         }
1497                         return $object;
1498                 }
1499
1500                 $object = ActivityPub::fetchContent($url, $uid);
1501                 if (empty($object)) {
1502                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
1503                         // We perform negative caching.
1504                         DI::cache()->set($cachekey, [], Duration::FIVE_MINUTES);
1505                         return [];
1506                 }
1507
1508                 if (empty($object['id'])) {
1509                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1510                         return [];
1511                 }
1512                 DI::cache()->set($cachekey, $object, Duration::FIVE_MINUTES);
1513
1514                 Logger::debug('Activity was fetched successfully', ['url' => $url, 'uid' => $uid]);
1515
1516                 return $object;
1517         }
1518
1519         /**
1520          * Fetches missing posts
1521          *
1522          * @param string     $url         message URL
1523          * @param array      $child       activity array with the child of this message
1524          * @param string     $relay_actor Relay actor
1525          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1526          * @param int        $uid         User id that is used to fetch the activity
1527          * @return string fetched message URL
1528          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1529          * @throws \ImagickException
1530          */
1531         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL, int $uid = 0): string
1532         {
1533                 $object = self::fetchCachedActivity($url, $uid);
1534                 if (empty($object)) {
1535                         return '';
1536                 }
1537
1538                 $signer = [];
1539
1540                 if (!empty($object['attributedTo'])) {
1541                         $attributed_to = $object['attributedTo'];
1542                         if (is_array($attributed_to)) {
1543                                 $compacted = JsonLD::compact($object);
1544                                 $attributed_to = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1545                         }
1546                         $signer[] = $attributed_to;
1547                 }
1548
1549                 if (!empty($object['actor'])) {
1550                         $object_actor = $object['actor'];
1551                 } elseif (!empty($attributed_to)) {
1552                         $object_actor = $attributed_to;
1553                 } else {
1554                         // Shouldn't happen
1555                         $object_actor = '';
1556                 }
1557
1558                 $signer[] = $object_actor;
1559
1560                 if (!empty($child['author'])) {
1561                         $actor = $child['author'];
1562                         $signer[] = $actor;
1563                 } else {
1564                         $actor = $object_actor;
1565                 }
1566
1567                 if (!empty($object['published'])) {
1568                         $published = $object['published'];
1569                 } elseif (!empty($child['published'])) {
1570                         $published = $child['published'];
1571                 } else {
1572                         $published = DateTimeFormat::utcNow();
1573                 }
1574
1575                 $activity = [];
1576                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1577                 unset($object['@context']);
1578                 $activity['id'] = $object['id'];
1579                 $activity['to'] = $object['to'] ?? [];
1580                 $activity['cc'] = $object['cc'] ?? [];
1581                 $activity['audience'] = $object['audience'] ?? [];
1582                 $activity['actor'] = $actor;
1583                 $activity['object'] = $object;
1584                 $activity['published'] = $published;
1585                 $activity['type'] = 'Create';
1586
1587                 $ldactivity = JsonLD::compact($activity);
1588
1589                 $ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 0;
1590
1591                 if ($object_actor != $actor) {
1592                         Contact::updateByUrlIfNeeded($object_actor);
1593                 }
1594
1595                 Contact::updateByUrlIfNeeded($actor);
1596
1597                 if (!empty($child['thread-completion'])) {
1598                         $ldactivity['thread-completion'] = $child['thread-completion'];
1599                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1600                 } else {
1601                         $ldactivity['thread-completion'] = Contact::getIdForURL($relay_actor ?: $actor);
1602                         $ldactivity['completion-mode']   = $completion;
1603                 }
1604
1605                 if ($completion == Receiver::COMPLETION_RELAY) {
1606                         $ldactivity['from-relay'] = $ldactivity['thread-completion'];
1607                         if (!self::acceptIncomingMessage($ldactivity, $object['id'])) {
1608                                 return '';
1609                         }
1610                 }
1611
1612                 if (!empty($child['thread-children-type'])) {
1613                         $ldactivity['thread-children-type'] = $child['thread-children-type'];
1614                 } elseif (!empty($child['type'])) {
1615                         $ldactivity['thread-children-type'] = $child['type'];
1616                 } else {
1617                         $ldactivity['thread-children-type'] = 'as:Create';
1618                 }
1619
1620                 if (($completion == Receiver::COMPLETION_RELAY) && Queue::exists($url, 'as:Create')) {
1621                         Logger::info('Activity has already been queued.', ['url' => $url, 'object' => $activity['id']]);
1622                 } elseif (ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer, '', $completion)) {
1623                         Logger::info('Activity had been fetched and processed.', ['url' => $url, 'entry' => $child['entry-id'] ?? 0, 'completion' => $completion, 'object' => $activity['id']]);
1624                 } else {
1625                         Logger::info('Activity had been fetched and will be processed later.', ['url' => $url, 'entry' => $child['entry-id'] ?? 0, 'completion' => $completion, 'object' => $activity['id']]);
1626                 }
1627
1628                 return $activity['id'];
1629         }
1630
1631         /**
1632          * Test if incoming relay messages should be accepted
1633          *
1634          * @param array $activity activity array
1635          * @param string $id      object ID
1636          * @return boolean true if message is accepted
1637          */
1638         private static function acceptIncomingMessage(array $activity, string $id): bool
1639         {
1640                 if (empty($activity['as:object'])) {
1641                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1642                         return true;
1643                 }
1644
1645                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1646                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1647                 if (Post::exists(['uri-id' => $uriid])) {
1648                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1649                         return true;
1650                 }
1651
1652                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1653                 $authorid = Contact::getIdForURL($attributed_to);
1654
1655                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1656
1657                 $messageTags = [];
1658                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1659                 if (!empty($tags)) {
1660                         foreach ($tags as $tag) {
1661                                 if ($tag['type'] != 'Hashtag') {
1662                                         continue;
1663                                 }
1664                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1665                         }
1666                 }
1667
1668                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB, $activity['thread-completion'] ?? 0);
1669         }
1670
1671         /**
1672          * perform a "follow" request
1673          *
1674          * @param array $activity
1675          * @return void
1676          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1677          * @throws \ImagickException
1678          */
1679         public static function followUser(array $activity)
1680         {
1681                 $uid = User::getIdForURL($activity['object_id']);
1682                 if (empty($uid)) {
1683                         Queue::remove($activity);
1684                         return;
1685                 }
1686
1687                 $owner = User::getOwnerDataById($uid);
1688                 if (empty($owner)) {
1689                         return;
1690                 }
1691
1692                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1693                 if (!empty($cid)) {
1694                         self::switchContact($cid);
1695                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1696                 }
1697
1698                 $item = [
1699                         'author-id' => Contact::getIdForURL($activity['actor']),
1700                         'author-link' => $activity['actor'],
1701                 ];
1702
1703                 // Ensure that the contact has got the right network type
1704                 self::switchContact($item['author-id']);
1705
1706                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1707                 if ($result === true) {
1708                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1709                 }
1710
1711                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1712                 if (empty($cid)) {
1713                         return;
1714                 }
1715
1716                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1717                         self::transmitPendingEvents($cid, $owner['uid']);
1718                 }
1719
1720                 if (empty($contact)) {
1721                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1722                 }
1723                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1724                 Queue::remove($activity);
1725         }
1726
1727         /**
1728          * Transmit pending events to the new follower
1729          *
1730          * @param integer $cid Contact id
1731          * @param integer $uid User id
1732          * @return void
1733          */
1734         private static function transmitPendingEvents(int $cid, int $uid)
1735         {
1736                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1737                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1738
1739                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1740                 while ($event = DBA::fetch($events)) {
1741                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1742                         if (empty($post)) {
1743                                 continue;
1744                         }
1745                         if (DI::config()->get('system', 'bulk_delivery')) {
1746                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1747                                 Worker::add(Worker::PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1748                         } else {
1749                                 Worker::add(Worker::PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1750                         }
1751                 }
1752         }
1753
1754         /**
1755          * Update the given profile
1756          *
1757          * @param array $activity
1758          * @throws \Exception
1759          */
1760         public static function updatePerson(array $activity)
1761         {
1762                 if (empty($activity['object_id'])) {
1763                         return;
1764                 }
1765
1766                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1767                 Contact::updateFromProbeByURL($activity['object_id']);
1768                 Queue::remove($activity);
1769         }
1770
1771         /**
1772          * Delete the given profile
1773          *
1774          * @param array $activity
1775          * @return void
1776          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1777          */
1778         public static function deletePerson(array $activity)
1779         {
1780                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1781                         Logger::info('Empty object id or actor.');
1782                         Queue::remove($activity);
1783                         return;
1784                 }
1785
1786                 if ($activity['object_id'] != $activity['actor']) {
1787                         Logger::info('Object id does not match actor.');
1788                         Queue::remove($activity);
1789                         return;
1790                 }
1791
1792                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1793                 while ($contact = DBA::fetch($contacts)) {
1794                         Contact::remove($contact['id']);
1795                 }
1796                 DBA::close($contacts);
1797
1798                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1799                 Queue::remove($activity);
1800         }
1801
1802         /**
1803          * Add moved contacts as followers for all subscribers of the old contact
1804          *
1805          * @param array $activity
1806          * @return void
1807          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1808          */
1809         public static function movePerson(array $activity)
1810         {
1811                 if (empty($activity['target_id']) || empty($activity['object_id'])) {
1812                         Queue::remove($activity);
1813                         return;
1814                 }
1815
1816                 if ($activity['object_id'] != $activity['actor']) {
1817                         Logger::notice('Object is not the actor', ['activity' => $activity]);
1818                         Queue::remove($activity);
1819                         return;
1820                 }
1821
1822                 $from = Contact::getByURL($activity['object_id'], false, ['uri-id']);
1823                 if (empty($from['uri-id'])) {
1824                         Logger::info('Object not found', ['activity' => $activity]);
1825                         Queue::remove($activity);
1826                         return;
1827                 }
1828
1829                 $contacts = DBA::select('contact', ['uid', 'url'], ["`uri-id` = ? AND `uid` != ? AND `rel` IN (?, ?)", $from['uri-id'], 0, Contact::FRIEND, Contact::SHARING]);
1830                 while ($from_contact = DBA::fetch($contacts)) {
1831                         $result = Contact::createFromProbeForUser($from_contact['uid'], $activity['target_id']);
1832                         Logger::debug('Follower added', ['from' => $from_contact, 'result' => $result]);
1833                 }
1834                 DBA::close($contacts);
1835                 Queue::remove($activity);
1836         }
1837
1838         /**
1839          * Blocks the user by the contact
1840          *
1841          * @param array $activity
1842          * @return void
1843          * @throws \Exception
1844          */
1845         public static function blockAccount(array $activity)
1846         {
1847                 $cid = Contact::getIdForURL($activity['actor']);
1848                 if (empty($cid)) {
1849                         return;
1850                 }
1851
1852                 $uid = User::getIdForURL($activity['object_id']);
1853                 if (empty($uid)) {
1854                         return;
1855                 }
1856
1857                 Contact\User::setIsBlocked($cid, $uid, true);
1858
1859                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1860                 Queue::remove($activity);
1861         }
1862
1863         /**
1864          * Unblocks the user by the contact
1865          *
1866          * @param array $activity
1867          * @return void
1868          * @throws \Exception
1869          */
1870         public static function unblockAccount(array $activity)
1871         {
1872                 $cid = Contact::getIdForURL($activity['actor']);
1873                 if (empty($cid)) {
1874                         return;
1875                 }
1876
1877                 $uid = User::getIdForURL($activity['object_object']);
1878                 if (empty($uid)) {
1879                         return;
1880                 }
1881
1882                 Contact\User::setIsBlocked($cid, $uid, false);
1883
1884                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1885                 Queue::remove($activity);
1886         }
1887
1888         /**
1889          * Report a user
1890          *
1891          * @param array $activity
1892          * @return void
1893          * @throws \Exception
1894          */
1895         public static function ReportAccount(array $activity)
1896         {
1897                 $account = Contact::getByURL($activity['object_id'], null, ['id', 'gsid']);
1898                 if (empty($account)) {
1899                         Logger::info('Unknown account', ['activity' => $activity]);
1900                         Queue::remove($activity);
1901                         return;
1902                 }
1903
1904                 $reporter_id = Contact::getIdForURL($activity['actor']);
1905                 if (empty($reporter_id)) {
1906                         Logger::info('Unknown actor', ['activity' => $activity]);
1907                         Queue::remove($activity);
1908                         return;
1909                 }
1910
1911                 $uri_ids = [];
1912                 foreach ($activity['object_ids'] as $status_id) {
1913                         $post = Post::selectFirst(['uri-id'], ['uri' => $status_id]);
1914                         if (!empty($post['uri-id'])) {
1915                                 $uri_ids[] = $post['uri-id'];
1916                         }
1917                 }
1918
1919                 $report = DI::reportFactory()->createFromReportsRequest(System::getRules(true), $reporter_id, $account['id'], $account['gsid'], $activity['content'], 'other', false, $uri_ids);
1920                 DI::report()->save($report);
1921
1922                 Logger::info('Stored report', ['reporter' => $reporter_id, 'account' => $account, 'comment' => $activity['content'], 'object_ids' => $activity['object_ids']]);
1923         }
1924
1925         /**
1926          * Accept a follow request
1927          *
1928          * @param array $activity
1929          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1930          * @throws \ImagickException
1931          */
1932         public static function acceptFollowUser(array $activity)
1933         {
1934                 if (!empty($activity['object_actor'])) {
1935                         $uid      = User::getIdForURL($activity['object_actor']);
1936                         $check_id = false;
1937                 } elseif (!empty($activity['receiver']) && (count($activity['receiver']) == 1)) {
1938                         $uid      = array_shift($activity['receiver']);
1939                         $check_id = true;
1940                 }
1941
1942                 if (empty($uid)) {
1943                         Logger::notice('User could not be detected', ['activity' => $activity]);
1944                         Queue::remove($activity);
1945                         return;
1946                 }
1947
1948                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1949                 if (empty($cid)) {
1950                         Logger::notice('No contact found', ['actor' => $activity['actor']]);
1951                         Queue::remove($activity);
1952                         return;
1953                 }
1954
1955                 $id = Transmitter::activityIDFromContact($cid);
1956                 if ($id == $activity['object_id']) {
1957                         Logger::info('Successful id check', ['uid' => $uid, 'cid' => $cid]);
1958                 } else {
1959                         Logger::info('Unsuccessful id check', ['uid' => $uid, 'cid' => $cid, 'id' => $id, 'object_id' => $activity['object_id']]);
1960                         if ($check_id) {
1961                                 Queue::remove($activity);
1962                                 return;
1963                         }
1964                 }
1965
1966                 self::switchContact($cid);
1967
1968                 $fields = ['pending' => false];
1969
1970                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1971                 if ($contact['rel'] == Contact::FOLLOWER) {
1972                         $fields['rel'] = Contact::FRIEND;
1973                 }
1974
1975                 $condition = ['id' => $cid];
1976                 Contact::update($fields, $condition);
1977                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1978                 Queue::remove($activity);
1979         }
1980
1981         /**
1982          * Reject a follow request
1983          *
1984          * @param array $activity
1985          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1986          * @throws \ImagickException
1987          */
1988         public static function rejectFollowUser(array $activity)
1989         {
1990                 $uid = User::getIdForURL($activity['object_actor']);
1991                 if (empty($uid)) {
1992                         return;
1993                 }
1994
1995                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1996                 if (empty($cid)) {
1997                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1998                         return;
1999                 }
2000
2001                 self::switchContact($cid);
2002
2003                 $contact = Contact::getById($cid, ['rel']);
2004                 if ($contact['rel'] == Contact::SHARING) {
2005                         Contact::remove($cid);
2006                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
2007                 } elseif ($contact['rel'] == Contact::FRIEND) {
2008                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
2009                 } else {
2010                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
2011                 }
2012                 Queue::remove($activity);
2013         }
2014
2015         /**
2016          * Undo activity like "like" or "dislike"
2017          *
2018          * @param array $activity
2019          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2020          * @throws \ImagickException
2021          */
2022         public static function undoActivity(array $activity)
2023         {
2024                 if (empty($activity['object_id'])) {
2025                         return;
2026                 }
2027
2028                 if (empty($activity['object_actor'])) {
2029                         return;
2030                 }
2031
2032                 $author_id = Contact::getIdForURL($activity['object_actor']);
2033                 if (empty($author_id)) {
2034                         return;
2035                 }
2036
2037                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => Item::GRAVITY_ACTIVITY]);
2038                 Queue::remove($activity);
2039         }
2040
2041         /**
2042          * Activity to remove a follower
2043          *
2044          * @param array $activity
2045          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2046          * @throws \ImagickException
2047          */
2048         public static function undoFollowUser(array $activity)
2049         {
2050                 $uid = User::getIdForURL($activity['object_object']);
2051                 if (empty($uid)) {
2052                         return;
2053                 }
2054
2055                 $owner = User::getOwnerDataById($uid);
2056                 if (empty($owner)) {
2057                         return;
2058                 }
2059
2060                 $cid = Contact::getIdForURL($activity['actor'], $uid);
2061                 if (empty($cid)) {
2062                         Logger::info('No contact found', ['actor' => $activity['actor']]);
2063                         return;
2064                 }
2065
2066                 self::switchContact($cid);
2067
2068                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
2069                 if (!DBA::isResult($contact)) {
2070                         return;
2071                 }
2072
2073                 Contact::removeFollower($contact);
2074                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
2075                 Queue::remove($activity);
2076         }
2077
2078         /**
2079          * Switches a contact to AP if needed
2080          *
2081          * @param integer $cid Contact ID
2082          * @return void
2083          * @throws \Exception
2084          */
2085         private static function switchContact(int $cid)
2086         {
2087                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
2088                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
2089                         return;
2090                 }
2091
2092                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
2093                 Contact::updateFromProbe($cid);
2094         }
2095
2096         /**
2097          * Collects implicit mentions like:
2098          * - the author of the parent item
2099          * - all the mentioned conversants in the parent item
2100          *
2101          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
2102          * @return array
2103          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2104          */
2105         private static function getImplicitMentionList(array $parent): array
2106         {
2107                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
2108
2109                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
2110
2111                 $implicit_mentions = [];
2112                 if (empty($parent_author['url'])) {
2113                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
2114                 } else {
2115                         $implicit_mentions[] = $parent_author['url'];
2116                         $implicit_mentions[] = $parent_author['nurl'];
2117                         $implicit_mentions[] = $parent_author['alias'];
2118                 }
2119
2120                 if (!empty($parent['alias'])) {
2121                         $implicit_mentions[] = $parent['alias'];
2122                 }
2123
2124                 foreach ($parent_terms as $term) {
2125                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
2126                         if (!empty($contact['url'])) {
2127                                 $implicit_mentions[] = $contact['url'];
2128                                 $implicit_mentions[] = $contact['nurl'];
2129                                 $implicit_mentions[] = $contact['alias'];
2130                         }
2131                 }
2132
2133                 return $implicit_mentions;
2134         }
2135
2136         /**
2137          * Strips from the body prepended implicit mentions
2138          *
2139          * @param string $body
2140          * @param array $parent
2141          * @return string
2142          */
2143         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
2144         {
2145                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
2146                         return $body;
2147                 }
2148
2149                 $potential_mentions = self::getImplicitMentionList($parent);
2150
2151                 $kept_mentions = [];
2152
2153                 // Extract one prepended mention at a time from the body
2154                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
2155                         if (!in_array($matches[2], $potential_mentions)) {
2156                                 $kept_mentions[] = $matches[1];
2157                         }
2158
2159                         $body = $matches[3];
2160                 }
2161
2162                 // Re-appending the kept mentions to the body after extraction
2163                 $kept_mentions[] = $body;
2164
2165                 return implode('', $kept_mentions);
2166         }
2167
2168         /**
2169          * Adds links to string mentions
2170          *
2171          * @param string $body
2172          * @param array  $tags
2173          * @return string
2174          */
2175         protected static function addMentionLinks(string $body, array $tags): string
2176         {
2177                 // This prevents links to be added again to Pleroma-style mention links
2178                 $body = self::normalizeMentionLinks($body);
2179
2180                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
2181                         foreach ($tags as $tag) {
2182                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
2183                                         continue;
2184                                 }
2185
2186                                 $hash = substr($tag['name'], 0, 1);
2187                                 $name = substr($tag['name'], 1);
2188                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
2189                                         $hash = '';
2190                                         $name = $tag['name'];
2191                                 }
2192
2193                                 if (Network::isValidHttpUrl($tag['href'])) {
2194                                         $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
2195                                 }
2196                         }
2197
2198                         return $body;
2199                 });
2200
2201                 return $body;
2202         }
2203 }