src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2022, 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\Logger;
  28 use Friendica\Core\Protocol;
  29 use Friendica\Core\System;
  30 use Friendica\Database\DBA;
  31 use Friendica\DI;
  32 use Friendica\Model\APContact;
  33 use Friendica\Model\Contact;
  34 use Friendica\Model\Conversation;
  35 use Friendica\Model\Event;
  36 use Friendica\Model\GServer;
  37 use Friendica\Model\Item;
  38 use Friendica\Model\ItemURI;
  39 use Friendica\Model\Mail;
  40 use Friendica\Model\Tag;
  41 use Friendica\Model\User;
  42 use Friendica\Model\Post;
  43 use Friendica\Protocol\Activity;
  44 use Friendica\Protocol\ActivityPub;
  45 use Friendica\Protocol\Relay;
  46 use Friendica\Util\DateTimeFormat;
  47 use Friendica\Util\JsonLD;
  48 use Friendica\Util\Strings;
  49
  50 /**
  51  * ActivityPub Processor Protocol class
  52  */
  53 class Processor
  54 {
  55         /**
  56          * Extracts the tag character (#, @, !) from mention links
  57          *
  58          * @param string $body
  59          * @return string
  60          */
  61         protected static function normalizeMentionLinks(string $body): string
  62         {
  63                 return preg_replace('%\[url=([^\[\]]*)]([#@!])(.*?)\[/url]%ism', '$2[url=$1]$3[/url]', $body);
  64         }
  65
  66         /**
  67          * Convert the language array into a language JSON
  68          *
  69          * @param array $languages
  70          * @return string language JSON
  71          */
  72         private static function processLanguages(array $languages)
  73         {
  74                 $codes = array_keys($languages);
  75                 $lang = [];
  76                 foreach ($codes as $code) {
  77                         $lang[$code] = 1;
  78                 }
  79
  80                 if (empty($lang)) {
  81                         return '';
  82                 }
  83
  84                 return json_encode($lang);
  85         }
  86         /**
  87          * Replaces emojis in the body
  88          *
  89          * @param array $emojis
  90          * @param string $body
  91          *
  92          * @return string with replaced emojis
  93          */
  94         private static function replaceEmojis(int $uri_id, $body, array $emojis)
  95         {
  96                 $body = strtr($body,
  97                         array_combine(
  98                                 array_column($emojis, 'name'),
  99                                 array_map(function ($emoji) {
 100                                         return '[emoji=' . $emoji['href'] . ']' . $emoji['name'] . '[/emoji]';
 101                                 }, $emojis)
 102                         )
 103                 );
 104
 105                 // We store the emoji here to be able to avoid storing it in the media
 106                 foreach ($emojis as $emoji) {
 107                         Post\Link::getByLink($uri_id, $emoji['href']);
 108                 }
 109                 return $body;
 110         }
 111
 112         /**
 113          * Store attached media files in the post-media table
 114          *
 115          * @param int $uriid
 116          * @param array $attachment
 117          * @return void
 118          */
 119         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
 120         {
 121                 if (empty($attachment['url'])) {
 122                         return;
 123                 }
 124
 125                 $data = ['uri-id' => $uriid];
 126                 $data['type'] = Post\Media::UNKNOWN;
 127                 $data['url'] = $attachment['url'];
 128                 $data['mimetype'] = $attachment['mediaType'] ?? null;
 129                 $data['height'] = $attachment['height'] ?? null;
 130                 $data['width'] = $attachment['width'] ?? null;
 131                 $data['size'] = $attachment['size'] ?? null;
 132                 $data['preview'] = $attachment['image'] ?? null;
 133                 $data['description'] = $attachment['name'] ?? null;
 134
 135                 Post\Media::insert($data);
 136         }
 137
 138         /**
 139          * Stire attachment data
 140          *
 141          * @param array   $activity
 142          * @param array   $item
 143          */
 144         private static function storeAttachments($activity, $item)
 145         {
 146                 if (empty($activity['attachments'])) {
 147                         return;
 148                 }
 149
 150                 foreach ($activity['attachments'] as $attach) {
 151                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 152                 }
 153         }
 154
 155         /**
 156          * Store attachment data
 157          *
 158          * @param array   $activity
 159          * @param array   $item
 160          */
 161         private static function storeQuestion($activity, $item)
 162         {
 163                 if (empty($activity['question'])) {
 164                         return;
 165                 }
 166                 $question = ['multiple' => $activity['question']['multiple']];
 167
 168                 if (!empty($activity['question']['voters'])) {
 169                         $question['voters'] = $activity['question']['voters'];
 170                 }
 171
 172                 if (!empty($activity['question']['end-time'])) {
 173                         $question['end-time'] = DateTimeFormat::utc($activity['question']['end-time']);
 174                 }
 175
 176                 Post\Question::update($item['uri-id'], $question);
 177
 178                 foreach ($activity['question']['options'] as $key => $option) {
 179                         $option = ['name' => $option['name'], 'replies' => $option['replies']];
 180                         Post\QuestionOption::update($item['uri-id'], $key, $option);
 181                 }
 182
 183                 Logger::debug('Storing incoming question', ['type' => $activity['type'], 'uri-id' => $item['uri-id'], 'question' => $activity['question']]);
 184         }
 185
 186         /**
 187          * Updates a message
 188          *
 189          * @param array $activity Activity array
 190          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 191          */
 192         public static function updateItem($activity)
 193         {
 194                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type'], ['uri' => $activity['id']]);
 195                 if (!DBA::isResult($item)) {
 196                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 197                         $item = self::createItem($activity);
 198                         if (empty($item)) {
 199                                 return;
 200                         }
 201
 202                         self::postItem($activity, $item);
 203                         return;
 204                 }
 205
 206                 $item['changed'] = DateTimeFormat::utcNow();
 207                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 208
 209                 $item = self::processContent($activity, $item);
 210
 211                 self::storeAttachments($activity, $item);
 212                 self::storeQuestion($activity, $item);
 213
 214                 if (empty($item)) {
 215                         return;
 216                 }
 217
 218                 Item::update($item, ['uri' => $activity['id']]);
 219
 220                 if ($activity['object_type'] == 'as:Event') {
 221                         $posts = Post::select(['event-id', 'uid'], ["`uri` = ? AND `event-id` > ?", $activity['id'], 0]);
 222                         while ($post = DBA::fetch($posts)) {
 223                                 self::updateEvent($post['event-id'], $activity);
 224                         }
 225                 }
 226         }
 227
 228         /**
 229          * Update an existing event
 230          *
 231          * @param int $event_id
 232          * @param array $activity
 233          */
 234         private static function updateEvent(int $event_id, array $activity)
 235         {
 236                 $event = DBA::selectFirst('event', [], ['id' => $event_id]);
 237
 238                 $event['edited']   = DateTimeFormat::utc($activity['updated']);
 239                 $event['summary']  = HTML::toBBCode($activity['name']);
 240                 $event['desc']     = HTML::toBBCode($activity['content']);
 241                 if (!empty($activity['start-time'])) {
 242                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 243                 }
 244                 if (!empty($activity['end-time'])) {
 245                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 246                 }
 247                 $event['nofinish'] = empty($event['finish']);
 248                 $event['location'] = $activity['location'];
 249
 250                 Logger::info('Updating event', ['uri' => $activity['id'], 'id' => $event_id]);
 251                 Event::store($event);
 252         }
 253
 254         /**
 255          * Prepares data for a message
 256          *
 257          * @param array $activity Activity array
 258          * @return array Internal item
 259          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 260          * @throws \ImagickException
 261          */
 262         public static function createItem($activity)
 263         {
 264                 $item = [];
 265                 $item['verb'] = Activity::POST;
 266                 $item['thr-parent'] = $activity['reply-to-id'];
 267
 268                 if ($activity['reply-to-id'] == $activity['id']) {
 269                         $item['gravity'] = GRAVITY_PARENT;
 270                         $item['object-type'] = Activity\ObjectType::NOTE;
 271                 } else {
 272                         $item['gravity'] = GRAVITY_COMMENT;
 273                         $item['object-type'] = Activity\ObjectType::COMMENT;
 274                 }
 275
 276                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 277                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 278                         self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 279                 }
 280
 281                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 282
 283                 /// @todo What to do with $activity['context']?
 284                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 285                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 286                         return [];
 287                 }
 288
 289                 $item['network'] = Protocol::ACTIVITYPUB;
 290                 $item['author-link'] = $activity['author'];
 291                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 292                 $item['owner-link'] = $activity['actor'];
 293                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 294
 295                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 296                         $item['private'] = Item::UNLISTED;
 297                 } elseif (in_array(0, $activity['receiver'])) {
 298                         $item['private'] = Item::PUBLIC;
 299                 } else {
 300                         $item['private'] = Item::PRIVATE;
 301                 }
 302
 303                 if (!empty($activity['raw'])) {
 304                         $item['source'] = $activity['raw'];
 305                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 306                         $item['conversation-href'] = $activity['context'] ?? '';
 307                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 308
 309                         if (isset($activity['push'])) {
 310                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 311                         }
 312                 }
 313
 314                 if (!empty($activity['from-relay'])) {
 315                         $item['direction'] = Conversation::RELAY;
 316                 }
 317
 318                 if ($activity['object_type'] == 'as:Article') {
 319                         $item['post-type'] = Item::PT_ARTICLE;
 320                 } elseif ($activity['object_type'] == 'as:Audio') {
 321                         $item['post-type'] = Item::PT_AUDIO;
 322                 } elseif ($activity['object_type'] == 'as:Document') {
 323                         $item['post-type'] = Item::PT_DOCUMENT;
 324                 } elseif ($activity['object_type'] == 'as:Event') {
 325                         $item['post-type'] = Item::PT_EVENT;
 326                 } elseif ($activity['object_type'] == 'as:Image') {
 327                         $item['post-type'] = Item::PT_IMAGE;
 328                 } elseif ($activity['object_type'] == 'as:Page') {
 329                         $item['post-type'] = Item::PT_PAGE;
 330                 } elseif ($activity['object_type'] == 'as:Question') {
 331                         $item['post-type'] = Item::PT_POLL;
 332                 } elseif ($activity['object_type'] == 'as:Video') {
 333                         $item['post-type'] = Item::PT_VIDEO;
 334                 } else {
 335                         $item['post-type'] = Item::PT_NOTE;
 336                 }
 337
 338                 $item['isForum'] = false;
 339
 340                 if (!empty($activity['thread-completion'])) {
 341                         if ($activity['thread-completion'] != $item['owner-id']) {
 342                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 343                                 $item['causer-link'] = $actor['url'];
 344                                 $item['causer-id'] = $activity['thread-completion'];
 345                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 346                         } else {
 347                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 348                                 $item['causer-link'] = $item['owner-link'];
 349                                 $item['causer-id']   = $item['owner-id'];
 350                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 351                         }
 352
 353                         $item['owner-link'] = $item['author-link'];
 354                         $item['owner-id'] = $item['author-id'];
 355                 } else {
 356                         $actor = APContact::getByURL($item['owner-link'], false);
 357                         $item['isForum'] = ($actor['type'] == 'Group');
 358                 }
 359
 360                 $item['uri'] = $activity['id'];
 361
 362                 if (empty($activity['published']) || empty($activity['updated'])) {
 363                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 364                 }
 365
 366                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 367                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 368                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 369                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 370
 371                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 372                 if (empty($item['uri-id'])) {
 373                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 374                         return [];
 375                 }
 376
 377                 $item = self::processContent($activity, $item);
 378                 if (empty($item)) {
 379                         Logger::info('Message was not processed');
 380                         return [];
 381                 }
 382
 383                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 384
 385                 self::storeAttachments($activity, $item);
 386                 self::storeQuestion($activity, $item);
 387
 388                 // We received the post via AP, so we set the protocol of the server to AP
 389                 $contact = Contact::getById($item['author-id'], ['gsid']);
 390                 if (!empty($contact['gsid'])) {
 391                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 392                 }
 393
 394                 if ($item['author-id'] != $item['owner-id']) {
 395                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 396                         if (!empty($contact['gsid'])) {
 397                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 398                         }
 399                 }
 400
 401                 return $item;
 402         }
 403
 404         /**
 405          * Delete items
 406          *
 407          * @param array $activity
 408          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 409          * @throws \ImagickException
 410          */
 411         public static function deleteItem($activity)
 412         {
 413                 $owner = Contact::getIdForURL($activity['actor']);
 414
 415                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 416                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 417         }
 418
 419         /**
 420          * Prepare the item array for an activity
 421          *
 422          * @param array $activity Activity array
 423          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 424          * @throws \ImagickException
 425          */
 426         public static function addTag($activity)
 427         {
 428                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 429                         return;
 430                 }
 431
 432                 foreach ($activity['receiver'] as $receiver) {
 433                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 434                         if (!DBA::isResult($item)) {
 435                                 // We don't fetch missing content for this purpose
 436                                 continue;
 437                         }
 438
 439                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 440                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 441                                 continue;
 442                         }
 443
 444                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 445                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 446                 }
 447         }
 448
 449         /**
 450          * Prepare the item array for an activity
 451          *
 452          * @param array  $activity Activity array
 453          * @param string $verb     Activity verb
 454          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 455          * @throws \ImagickException
 456          */
 457         public static function createActivity($activity, $verb)
 458         {
 459                 $item = self::createItem($activity);
 460                 if (empty($item)) {
 461                         return;
 462                 }
 463
 464                 $item['verb'] = $verb;
 465                 $item['thr-parent'] = $activity['object_id'];
 466                 $item['gravity'] = GRAVITY_ACTIVITY;
 467                 unset($item['post-type']);
 468                 $item['object-type'] = Activity\ObjectType::NOTE;
 469
 470                 if (!empty($activity['content'])) {
 471                         $item['body'] = HTML::toBBCode($activity['content']);
 472                 }
 473
 474                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 475
 476                 self::postItem($activity, $item);
 477         }
 478
 479         /**
 480          * Fetch the Uri-Id of a post for the "featured" collection
 481          *
 482          * @param array $activity
 483          * @return null|int
 484          */
 485         private static function getUriIdForFeaturedCollection(array $activity)
 486         {
 487                 $actor = APContact::getByURL($activity['actor']);
 488                 if (empty($actor)) {
 489                         return null;
 490                 }
 491
 492                 // Refetch the account when the "featured" collection is missing.
 493                 // This can be removed in a future version (end of 2022 should be good).
 494                 if (empty($actor['featured'])) {
 495                         $actor = APContact::getByURL($activity['actor'], true);
 496                         if (empty($actor)) {
 497                                 return null;
 498                         }
 499                 }
 500
 501                 if ($activity['target_id'] != $actor['featured']) {
 502                         return null;
 503                 }
 504
 505                 $id = Contact::getIdForURL($activity['actor']);
 506                 if (empty($id)) {
 507                         return null;
 508                 }
 509
 510                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id'], 'author-id' => $id]);
 511                 if (!empty($parent['uri-id'])) {
 512                         return $parent['uri-id'];
 513                 }
 514
 515                 return null;
 516         }
 517
 518         /**
 519          * Add a post to the "Featured" collection
 520          *
 521          * @param array $activity
 522          */
 523         public static function addToFeaturedCollection(array $activity)
 524         {
 525                 $uriid = self::getUriIdForFeaturedCollection($activity);
 526                 if (empty($uriid)) {
 527                         return;
 528                 }
 529
 530                 Logger::debug('Add post to featured collection', ['uri-id' => $uriid]);
 531
 532                 Post\Collection::add($uriid, Post\Collection::FEATURED);
 533         }
 534
 535         /**
 536          * Remove a post to the "Featured" collection
 537          *
 538          * @param array $activity
 539          */
 540         public static function removeFromFeaturedCollection(array $activity)
 541         {
 542                 $uriid = self::getUriIdForFeaturedCollection($activity);
 543                 if (empty($uriid)) {
 544                         return;
 545                 }
 546
 547                 Logger::debug('Remove post from featured collection', ['uri-id' => $uriid]);
 548
 549                 Post\Collection::remove($uriid, Post\Collection::FEATURED);
 550         }
 551
 552         /**
 553          * Create an event
 554          *
 555          * @param array $activity Activity array
 556          * @param array $item
 557          *
 558          * @return int event id
 559          * @throws \Exception
 560          */
 561         public static function createEvent($activity, $item)
 562         {
 563                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 564                 $event['desc']      = HTML::toBBCode($activity['content']);
 565                 if (!empty($activity['start-time'])) {
 566                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 567                 }
 568                 if (!empty($activity['end-time'])) {
 569                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 570                 }
 571                 $event['nofinish']  = empty($event['finish']);
 572                 $event['location']  = $activity['location'];
 573                 $event['cid']       = $item['contact-id'];
 574                 $event['uid']       = $item['uid'];
 575                 $event['uri']       = $item['uri'];
 576                 $event['edited']    = $item['edited'];
 577                 $event['private']   = $item['private'];
 578                 $event['guid']      = $item['guid'];
 579                 $event['plink']     = $item['plink'];
 580                 $event['network']   = $item['network'];
 581                 $event['protocol']  = $item['protocol'];
 582                 $event['direction'] = $item['direction'];
 583                 $event['source']    = $item['source'];
 584
 585                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 586                 if (DBA::isResult($ev)) {
 587                         $event['id'] = $ev['id'];
 588                 }
 589
 590                 $event_id = Event::store($event);
 591
 592                 Logger::info('Event was stored', ['id' => $event_id]);
 593
 594                 return $event_id;
 595         }
 596
 597         /**
 598          * Process the content
 599          *
 600          * @param array $activity Activity array
 601          * @param array $item
 602          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 603          * @throws \Exception
 604          */
 605         private static function processContent($activity, $item)
 606         {
 607                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 608                         $item['title'] = Markdown::toBBCode($activity['name']);
 609                         $content = Markdown::toBBCode($activity['content']);
 610                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 611                         $item['title'] = $activity['name'];
 612                         $content = $activity['content'];
 613                 } else {
 614                         // By default assume "text/html"
 615                         $item['title'] = HTML::toBBCode($activity['name']);
 616                         $content = HTML::toBBCode($activity['content']);
 617                 }
 618
 619                 if (!empty($activity['languages'])) {
 620                         $item['language'] = self::processLanguages($activity['languages']);
 621                 }
 622
 623                 if (!empty($activity['emojis'])) {
 624                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 625                 }
 626
 627                 $content = self::addMentionLinks($content, $activity['tags']);
 628
 629                 if (!empty($activity['source'])) {
 630                         $item['body'] = $activity['source'];
 631                         $item['raw-body'] = $content;
 632                         $item['body'] = Item::improveSharedDataInBody($item);
 633                 } else {
 634                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 635                                 $item_private = !in_array(0, $activity['item_receiver']);
 636                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 637                                 if (!DBA::isResult($parent)) {
 638                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 639                                         return false;
 640                                 }
 641                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 642                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 643                                         return false;
 644                                 }
 645
 646                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 647                         }
 648                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 649                         $item['raw-body'] = $item['body'] = $content;
 650                 }
 651
 652                 self::storeFromBody($item);
 653                 self::storeTags($item['uri-id'], $activity['tags']);
 654
 655                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 656
 657                 $item['location'] = $activity['location'];
 658
 659                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 660                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 661                 }
 662
 663                 $item['app'] = $activity['generator'];
 664
 665                 return $item;
 666         }
 667
 668         /**
 669          * Store hashtags and mentions
 670          *
 671          * @param array $item
 672          */
 673         private static function storeFromBody(array $item)
 674         {
 675                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 676                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 677
 678                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 679         }
 680
 681         /**
 682          * Generate a GUID out of an URL of an ActivityPub post.
 683          *
 684          * @param string $url message URL
 685          * @return string with GUID
 686          */
 687         private static function getGUIDByURL(string $url)
 688         {
 689                 $parsed = parse_url($url);
 690
 691                 $host_hash = hash('crc32', $parsed['host']);
 692
 693                 unset($parsed["scheme"]);
 694                 unset($parsed["host"]);
 695
 696                 $path = implode("/", $parsed);
 697
 698                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 699         }
 700
 701         /**
 702          * Checks if an incoming message is wanted
 703          *
 704          * @param array $activity
 705          * @param array $item
 706          * @return boolean Is the message wanted?
 707          */
 708         private static function isSolicitedMessage(array $activity, array $item)
 709         {
 710                 // The checks are split to improve the support when searching why a message was accepted.
 711                 if (count($activity['receiver']) != 1) {
 712                         // The message has more than one receiver, so it is wanted.
 713                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 714                         return true;
 715                 }
 716
 717                 if ($item['private'] == Item::PRIVATE) {
 718                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 719                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 720                         return true;
 721                 }
 722
 723                 if (!empty($activity['from-relay'])) {
 724                         // We check relay posts at another place. When it arrived here, the message is already checked.
 725                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 726                         return true;
 727                 }
 728
 729                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
 730                         // Manual completions and completions caused by reshares are allowed without any further checks.
 731                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 732                         return true;
 733                 }
 734
 735                 if ($item['gravity'] != GRAVITY_PARENT) {
 736                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 737                         // This can possibly be improved in the future.
 738                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 739                         return true;
 740                 }
 741
 742                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 743                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB)) {
 744                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 745                         return true;
 746                 } else {
 747                         return false;
 748                 }
 749         }
 750
 751         /**
 752          * Creates an item post
 753          *
 754          * @param array $activity Activity data
 755          * @param array $item     item array
 756          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 757          * @throws \ImagickException
 758          */
 759         public static function postItem(array $activity, array $item)
 760         {
 761                 if (empty($item)) {
 762                         return;
 763                 }
 764
 765                 $stored = false;
 766                 ksort($activity['receiver']);
 767
 768                 if (!self::isSolicitedMessage($activity, $item)) {
 769                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
 770                         return;
 771                 }
 772
 773                 foreach ($activity['receiver'] as $receiver) {
 774                         if ($receiver == -1) {
 775                                 continue;
 776                         }
 777
 778                         $item['uid'] = $receiver;
 779
 780                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 781                         switch($type) {
 782                                 case Receiver::TARGET_TO:
 783                                         $item['post-reason'] = Item::PR_TO;
 784                                         break;
 785                                 case Receiver::TARGET_CC:
 786                                         $item['post-reason'] = Item::PR_CC;
 787                                         break;
 788                                 case Receiver::TARGET_BTO:
 789                                         $item['post-reason'] = Item::PR_BTO;
 790                                         break;
 791                                 case Receiver::TARGET_BCC:
 792                                         $item['post-reason'] = Item::PR_BCC;
 793                                         break;
 794                                 case Receiver::TARGET_FOLLOWER:
 795                                         $item['post-reason'] = Item::PR_FOLLOWER;
 796                                         break;
 797                                 case Receiver::TARGET_ANSWER:
 798                                         $item['post-reason'] = Item::PR_COMMENT;
 799                                         break;
 800                                 case Receiver::TARGET_GLOBAL:
 801                                         $item['post-reason'] = Item::PR_GLOBAL;
 802                                         break;
 803                                 default:
 804                                         $item['post-reason'] = Item::PR_NONE;
 805                         }
 806
 807                         if (!empty($activity['from-relay'])) {
 808                                 $item['post-reason'] = Item::PR_RELAY;
 809                         } elseif (!empty($activity['thread-completion'])) {
 810                                 $item['post-reason'] = Item::PR_FETCHED;
 811                         }
 812
 813                         if ($item['isForum'] ?? false) {
 814                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 815                         } else {
 816                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 817                         }
 818
 819                         if (($receiver != 0) && empty($item['contact-id'])) {
 820                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 821                         }
 822
 823                         if (!empty($activity['directmessage'])) {
 824                                 self::postMail($activity, $item);
 825                                 continue;
 826                         }
 827
 828                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 829                                 if ($item['post-reason'] == Item::PR_BCC) {
 830                                         Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 831                                         continue;
 832                                 }
 833
 834                                 if (
 835                                         !empty($activity['thread-children-type'])
 836                                         && in_array($activity['thread-children-type'], Receiver::ACTIVITY_TYPES)
 837                                         && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE
 838                                 ) {
 839                                         Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
 840                                                 ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
 841                                         continue;
 842                                 }
 843                         }
 844
 845                         $is_forum = false;
 846
 847                         if ($receiver != 0) {
 848                                 $user = User::getById($receiver, ['account-type']);
 849                                 if (!empty($user['account-type'])) {
 850                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 851                                 }
 852                         }
 853
 854                         if (!$is_forum && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 855                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 856
 857                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 858                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 859                                 }
 860
 861                                 if ($skip) {
 862                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 863                                         continue;
 864                                 }
 865
 866                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 867                         }
 868
 869                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 870                                 $event_id = self::createEvent($activity, $item);
 871
 872                                 $item = Event::getItemArrayForImportedId($event_id, $item);
 873                         }
 874
 875                         $item_id = Item::insert($item);
 876                         if ($item_id) {
 877                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 878                         } else {
 879                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 880                         }
 881
 882                         if ($item['uid'] == 0) {
 883                                 $stored = $item_id;
 884                         }
 885                 }
 886
 887                 // Store send a follow request for every reshare - but only when the item had been stored
 888                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 889                         $author = APContact::getByURL($item['owner-link'], false);
 890                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 891                         if ($author['type'] != 'Group') {
 892                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 893                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 894                         }
 895                 }
 896         }
 897
 898         /**
 899          * Store tags and mentions into the tag table
 900          *
 901          * @param integer $uriid
 902          * @param array $tags
 903          */
 904         private static function storeTags(int $uriid, array $tags = null)
 905         {
 906                 foreach ($tags as $tag) {
 907                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 908                                 continue;
 909                         }
 910
 911                         $hash = substr($tag['name'], 0, 1);
 912
 913                         if ($tag['type'] == 'Mention') {
 914                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 915                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 916                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 917                                         $tag['name'] = substr($tag['name'], 1);
 918                                 }
 919                                 $type = Tag::IMPLICIT_MENTION;
 920
 921                                 if (!empty($tag['href'])) {
 922                                         $apcontact = APContact::getByURL($tag['href']);
 923                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 924                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 925                                         }
 926                                 }
 927                         } elseif ($tag['type'] == 'Hashtag') {
 928                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 929                                         $tag['name'] = substr($tag['name'], 1);
 930                                 }
 931                                 $type = Tag::HASHTAG;
 932                         }
 933
 934                         if (empty($tag['name'])) {
 935                                 continue;
 936                         }
 937
 938                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 939                 }
 940         }
 941
 942         public static function storeReceivers(int $uriid, array $receivers)
 943         {
 944                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
 945                         if (!empty($receivers[$element])) {
 946                                 foreach ($receivers[$element] as $receiver) {
 947                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
 948                                                 $name = Receiver::PUBLIC_COLLECTION;
 949                                         } else {
 950                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
 951                                         }
 952
 953                                         $target = Tag::getTargetType($receiver);
 954                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
 955                                         Tag::store($uriid, $type, $name, $receiver, $target);
 956                                 }
 957                         }
 958                 }
 959         }
 960
 961         /**
 962          * Creates an mail post
 963          *
 964          * @param array $activity Activity data
 965          * @param array $item     item array
 966          * @return int|bool New mail table row id or false on error
 967          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 968          */
 969         private static function postMail($activity, $item)
 970         {
 971                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 972                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 973                         return false;
 974                 }
 975
 976                 Logger::info('Direct Message', $item);
 977
 978                 $msg = [];
 979                 $msg['uid'] = $item['uid'];
 980
 981                 $msg['contact-id'] = $item['contact-id'];
 982
 983                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 984                 $msg['from-name'] = $contact['name'];
 985                 $msg['from-url'] = $contact['url'];
 986                 $msg['from-photo'] = $contact['photo'];
 987
 988                 $msg['uri'] = $item['uri'];
 989                 $msg['created'] = $item['created'];
 990
 991                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 992                 if (DBA::isResult($parent)) {
 993                         $msg['parent-uri'] = $parent['parent-uri'];
 994                         $msg['title'] = $parent['title'];
 995                 } else {
 996                         $msg['parent-uri'] = $item['thr-parent'];
 997
 998                         if (!empty($item['title'])) {
 999                                 $msg['title'] = $item['title'];
1000                         } elseif (!empty($item['content-warning'])) {
1001                                 $msg['title'] = $item['content-warning'];
1002                         } else {
1003                                 // Trying to generate a title out of the body
1004                                 $title = $item['body'];
1005
1006                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1007                                         $title = $matches[3];
1008                                 }
1009
1010                                 $title = trim(BBCode::toPlaintext($title));
1011
1012                                 if (strlen($title) > 20) {
1013                                         $title = substr($title, 0, 20) . '...';
1014                                 }
1015
1016                                 $msg['title'] = $title;
1017                         }
1018                 }
1019                 $msg['body'] = $item['body'];
1020
1021                 return Mail::insert($msg);
1022         }
1023
1024         /**
1025          * Fetch featured posts from a contact with the given url
1026          *
1027          * @param string $url
1028          * @return void
1029          */
1030         public static function fetchFeaturedPosts(string $url)
1031         {
1032                 Logger::info('Fetch featured posts', ['contact' => $url]);
1033
1034                 $apcontact = APContact::getByURL($url);
1035                 if (empty($apcontact['featured'])) {
1036                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1037                         return;
1038                 }
1039
1040                 $pcid = Contact::getIdForURL($url, 0, false);
1041                 if (empty($pcid)) {
1042                         Logger::info('Contact not found', ['contact' => $url]);
1043                         return;
1044                 }
1045
1046                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1047                 if (!empty($posts)) {
1048                         $old_featured = array_column($posts, 'uri-id');
1049                 } else {
1050                         $old_featured = [];
1051                 }
1052
1053                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1054                 if (empty($featured)) {
1055                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1056
1057                         foreach ($old_featured as $uri_id) {
1058                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1059                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1060                         }
1061                         return;
1062                 }
1063
1064                 $new = 0;
1065                 $old = 0;
1066
1067                 foreach ($featured as $post) {
1068                         if (empty($post['id'])) {
1069                                 continue;
1070                         }
1071                         $id = Item::fetchByLink($post['id']);
1072                         if (!empty($id)) {
1073                                 $item = Post::selectFirst(['uri-id', 'featured'], ['id' => $id]);
1074                                 if (!empty($item['uri-id'])) {
1075                                         if (!$item['featured']) {
1076                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED);
1077                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1078                                                 $new++;
1079                                         } else {
1080                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1081                                                 $old++;
1082                                         }
1083
1084                                         $index = array_search($item['uri-id'], $old_featured);
1085                                         if (!($index === false)) {
1086                                                 unset($old_featured[$index]);
1087                                         }
1088                                 }
1089                         }
1090                 }
1091
1092                 foreach ($old_featured as $uri_id) {
1093                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1094                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1095                 }
1096
1097                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1098         }
1099
1100         /**
1101          * Fetches missing posts
1102          *
1103          * @param string $url         message URL
1104          * @param array  $child       activity array with the child of this message
1105          * @param string $relay_actor Relay actor
1106          * @param int    $completion  Completion mode, see Receiver::COMPLETION_*
1107          * @return string fetched message URL
1108          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1109          */
1110         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL)
1111         {
1112                 if (!empty($child['receiver'])) {
1113                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
1114                 } else {
1115                         $uid = 0;
1116                 }
1117
1118                 $object = ActivityPub::fetchContent($url, $uid);
1119                 if (empty($object)) {
1120                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url]);
1121                         return '';
1122                 }
1123
1124                 if (empty($object['id'])) {
1125                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1126                         return '';
1127                 }
1128
1129                 if (!empty($object['actor'])) {
1130                         $object_actor = $object['actor'];
1131                 } elseif (!empty($object['attributedTo'])) {
1132                         $object_actor = $object['attributedTo'];
1133                         if (is_array($object_actor)) {
1134                                 $compacted = JsonLD::compact($object);
1135                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1136                         }
1137                 } else {
1138                         // Shouldn't happen
1139                         $object_actor = '';
1140                 }
1141
1142                 $signer = [$object_actor];
1143
1144                 if (!empty($child['author'])) {
1145                         $actor = $child['author'];
1146                         $signer[] = $actor;
1147                 } else {
1148                         $actor = $object_actor;
1149                 }
1150
1151                 if (!empty($object['published'])) {
1152                         $published = $object['published'];
1153                 } elseif (!empty($child['published'])) {
1154                         $published = $child['published'];
1155                 } else {
1156                         $published = DateTimeFormat::utcNow();
1157                 }
1158
1159                 $activity = [];
1160                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1161                 unset($object['@context']);
1162                 $activity['id'] = $object['id'];
1163                 $activity['to'] = $object['to'] ?? [];
1164                 $activity['cc'] = $object['cc'] ?? [];
1165                 $activity['actor'] = $actor;
1166                 $activity['object'] = $object;
1167                 $activity['published'] = $published;
1168                 $activity['type'] = 'Create';
1169
1170                 $ldactivity = JsonLD::compact($activity);
1171
1172                 if (!empty($relay_actor)) {
1173                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
1174                         $ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
1175                 } elseif (!empty($child['thread-completion'])) {
1176                         $ldactivity['thread-completion'] = $child['thread-completion'];
1177                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1178                 } else {
1179                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
1180                         $ldactivity['completion-mode']   = $completion;
1181                 }
1182
1183                 if (!empty($child['type'])) {
1184                         $ldactivity['thread-children-type'] = $child['type'];
1185                 }
1186
1187                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
1188                         return '';
1189                 }
1190
1191                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
1192
1193                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
1194
1195                 return $activity['id'];
1196         }
1197
1198         /**
1199          * Test if incoming relay messages should be accepted
1200          *
1201          * @param array $activity activity array
1202          * @param string $id      object ID
1203          * @return boolean true if message is accepted
1204          */
1205         private static function acceptIncomingMessage(array $activity, string $id)
1206         {
1207                 if (empty($activity['as:object'])) {
1208                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1209                         return true;
1210                 }
1211
1212                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1213                 $uriid = ItemURI::getIdByURI($replyto);
1214                 if (Post::exists(['uri-id' => $uriid])) {
1215                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1216                         return true;
1217                 }
1218
1219                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1220                 $authorid = Contact::getIdForURL($attributed_to);
1221
1222                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value'));
1223
1224                 $messageTags = [];
1225                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1226                 if (!empty($tags)) {
1227                         foreach ($tags as $tag) {
1228                                 if ($tag['type'] != 'Hashtag') {
1229                                         continue;
1230                                 }
1231                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1232                         }
1233                 }
1234
1235                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
1236         }
1237
1238         /**
1239          * perform a "follow" request
1240          *
1241          * @param array $activity
1242          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1243          * @throws \ImagickException
1244          */
1245         public static function followUser($activity)
1246         {
1247                 $uid = User::getIdForURL($activity['object_id']);
1248                 if (empty($uid)) {
1249                         return;
1250                 }
1251
1252                 $owner = User::getOwnerDataById($uid);
1253                 if (empty($owner)) {
1254                         return;
1255                 }
1256
1257                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1258                 if (!empty($cid)) {
1259                         self::switchContact($cid);
1260                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1261                 }
1262
1263                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
1264                         'author-link' => $activity['actor']];
1265
1266                 // Ensure that the contact has got the right network type
1267                 self::switchContact($item['author-id']);
1268
1269                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1270                 if ($result === true) {
1271                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1272                 }
1273
1274                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1275                 if (empty($cid)) {
1276                         return;
1277                 }
1278
1279                 if (empty($contact)) {
1280                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1281                 }
1282
1283                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1284         }
1285
1286         /**
1287          * Update the given profile
1288          *
1289          * @param array $activity
1290          * @throws \Exception
1291          */
1292         public static function updatePerson($activity)
1293         {
1294                 if (empty($activity['object_id'])) {
1295                         return;
1296                 }
1297
1298                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1299                 Contact::updateFromProbeByURL($activity['object_id']);
1300         }
1301
1302         /**
1303          * Delete the given profile
1304          *
1305          * @param array $activity
1306          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1307          */
1308         public static function deletePerson($activity)
1309         {
1310                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1311                         Logger::info('Empty object id or actor.');
1312                         return;
1313                 }
1314
1315                 if ($activity['object_id'] != $activity['actor']) {
1316                         Logger::info('Object id does not match actor.');
1317                         return;
1318                 }
1319
1320                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1321                 while ($contact = DBA::fetch($contacts)) {
1322                         Contact::remove($contact['id']);
1323                 }
1324                 DBA::close($contacts);
1325
1326                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1327         }
1328
1329         /**
1330          * Blocks the user by the contact
1331          *
1332          * @param array $activity
1333          * @throws \Exception
1334          */
1335         public static function blockAccount($activity)
1336         {
1337                 $cid = Contact::getIdForURL($activity['actor']);
1338                 if (empty($cid)) {
1339                         return;
1340                 }
1341
1342                 $uid = User::getIdForURL($activity['object_id']);
1343                 if (empty($uid)) {
1344                         return;
1345                 }
1346
1347                 Contact\User::setIsBlocked($cid, $uid, true);
1348
1349                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1350         }
1351
1352         /**
1353          * Unblocks the user by the contact
1354          *
1355          * @param array $activity
1356          * @throws \Exception
1357          */
1358         public static function unblockAccount($activity)
1359         {
1360                 $cid = Contact::getIdForURL($activity['actor']);
1361                 if (empty($cid)) {
1362                         return;
1363                 }
1364
1365                 $uid = User::getIdForURL($activity['object_object']);
1366                 if (empty($uid)) {
1367                         return;
1368                 }
1369
1370                 Contact\User::setIsBlocked($cid, $uid, false);
1371
1372                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1373         }
1374
1375         /**
1376          * Accept a follow request
1377          *
1378          * @param array $activity
1379          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1380          * @throws \ImagickException
1381          */
1382         public static function acceptFollowUser($activity)
1383         {
1384                 $uid = User::getIdForURL($activity['object_actor']);
1385                 if (empty($uid)) {
1386                         return;
1387                 }
1388
1389                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1390                 if (empty($cid)) {
1391                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1392                         return;
1393                 }
1394
1395                 self::switchContact($cid);
1396
1397                 $fields = ['pending' => false];
1398
1399                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1400                 if ($contact['rel'] == Contact::FOLLOWER) {
1401                         $fields['rel'] = Contact::FRIEND;
1402                 }
1403
1404                 $condition = ['id' => $cid];
1405                 Contact::update($fields, $condition);
1406                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1407         }
1408
1409         /**
1410          * Reject a follow request
1411          *
1412          * @param array $activity
1413          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1414          * @throws \ImagickException
1415          */
1416         public static function rejectFollowUser($activity)
1417         {
1418                 $uid = User::getIdForURL($activity['object_actor']);
1419                 if (empty($uid)) {
1420                         return;
1421                 }
1422
1423                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1424                 if (empty($cid)) {
1425                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1426                         return;
1427                 }
1428
1429                 self::switchContact($cid);
1430
1431                 $contact = Contact::getById($cid, ['rel']);
1432                 if ($contact['rel'] == Contact::SHARING) {
1433                         Contact::remove($cid);
1434                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1435                 } elseif ($contact['rel'] == Contact::FRIEND) {
1436                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1437                 } else {
1438                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1439                 }
1440         }
1441
1442         /**
1443          * Undo activity like "like" or "dislike"
1444          *
1445          * @param array $activity
1446          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1447          * @throws \ImagickException
1448          */
1449         public static function undoActivity($activity)
1450         {
1451                 if (empty($activity['object_id'])) {
1452                         return;
1453                 }
1454
1455                 if (empty($activity['object_actor'])) {
1456                         return;
1457                 }
1458
1459                 $author_id = Contact::getIdForURL($activity['object_actor']);
1460                 if (empty($author_id)) {
1461                         return;
1462                 }
1463
1464                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1465         }
1466
1467         /**
1468          * Activity to remove a follower
1469          *
1470          * @param array $activity
1471          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1472          * @throws \ImagickException
1473          */
1474         public static function undoFollowUser($activity)
1475         {
1476                 $uid = User::getIdForURL($activity['object_object']);
1477                 if (empty($uid)) {
1478                         return;
1479                 }
1480
1481                 $owner = User::getOwnerDataById($uid);
1482                 if (empty($owner)) {
1483                         return;
1484                 }
1485
1486                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1487                 if (empty($cid)) {
1488                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1489                         return;
1490                 }
1491
1492                 self::switchContact($cid);
1493
1494                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1495                 if (!DBA::isResult($contact)) {
1496                         return;
1497                 }
1498
1499                 Contact::removeFollower($contact);
1500                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1501         }
1502
1503         /**
1504          * Switches a contact to AP if needed
1505          *
1506          * @param integer $cid Contact ID
1507          * @throws \Exception
1508          */
1509         private static function switchContact($cid)
1510         {
1511                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1512                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1513                         return;
1514                 }
1515
1516                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1517                 Contact::updateFromProbe($cid);
1518         }
1519
1520         /**
1521          * Collects implicit mentions like:
1522          * - the author of the parent item
1523          * - all the mentioned conversants in the parent item
1524          *
1525          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1526          * @return array
1527          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1528          */
1529         private static function getImplicitMentionList(array $parent)
1530         {
1531                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1532
1533                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1534
1535                 $implicit_mentions = [];
1536                 if (empty($parent_author['url'])) {
1537                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1538                 } else {
1539                         $implicit_mentions[] = $parent_author['url'];
1540                         $implicit_mentions[] = $parent_author['nurl'];
1541                         $implicit_mentions[] = $parent_author['alias'];
1542                 }
1543
1544                 if (!empty($parent['alias'])) {
1545                         $implicit_mentions[] = $parent['alias'];
1546                 }
1547
1548                 foreach ($parent_terms as $term) {
1549                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1550                         if (!empty($contact['url'])) {
1551                                 $implicit_mentions[] = $contact['url'];
1552                                 $implicit_mentions[] = $contact['nurl'];
1553                                 $implicit_mentions[] = $contact['alias'];
1554                         }
1555                 }
1556
1557                 return $implicit_mentions;
1558         }
1559
1560         /**
1561          * Strips from the body prepended implicit mentions
1562          *
1563          * @param string $body
1564          * @param array $parent
1565          * @return string
1566          */
1567         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1568         {
1569                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1570                         return $body;
1571                 }
1572
1573                 $potential_mentions = self::getImplicitMentionList($parent);
1574
1575                 $kept_mentions = [];
1576
1577                 // Extract one prepended mention at a time from the body
1578                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1579                         if (!in_array($matches[2], $potential_mentions)) {
1580                                 $kept_mentions[] = $matches[1];
1581                         }
1582
1583                         $body = $matches[3];
1584                 }
1585
1586                 // Re-appending the kept mentions to the body after extraction
1587                 $kept_mentions[] = $body;
1588
1589                 return implode('', $kept_mentions);
1590         }
1591
1592         /**
1593          * Adds links to string mentions
1594          *
1595          * @param string $body
1596          * @param array  $tags
1597          * @return string
1598          */
1599         protected static function addMentionLinks(string $body, array $tags): string
1600         {
1601                 // This prevents links to be added again to Pleroma-style mention links
1602                 $body = self::normalizeMentionLinks($body);
1603
1604                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1605                         foreach ($tags as $tag) {
1606                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1607                                         continue;
1608                                 }
1609
1610                                 $hash = substr($tag['name'], 0, 1);
1611                                 $name = substr($tag['name'], 1);
1612                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1613                                         $hash = '';
1614                                         $name = $tag['name'];
1615                                 }
1616
1617                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1618                         }
1619
1620                         return $body;
1621                 });
1622
1623                 return $body;
1624         }
1625 }