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\Core\Worker;
  31 use Friendica\Database\DBA;
  32 use Friendica\DI;
  33 use Friendica\Model\APContact;
  34 use Friendica\Model\Contact;
  35 use Friendica\Model\Conversation;
  36 use Friendica\Model\Event;
  37 use Friendica\Model\GServer;
  38 use Friendica\Model\Item;
  39 use Friendica\Model\ItemURI;
  40 use Friendica\Model\Mail;
  41 use Friendica\Model\Tag;
  42 use Friendica\Model\User;
  43 use Friendica\Model\Post;
  44 use Friendica\Protocol\Activity;
  45 use Friendica\Protocol\ActivityPub;
  46 use Friendica\Protocol\Relay;
  47 use Friendica\Util\DateTimeFormat;
  48 use Friendica\Util\JsonLD;
  49 use Friendica\Util\Strings;
  50 use Friendica\Worker\Delivery;
  51
  52 /**
  53  * ActivityPub Processor Protocol class
  54  */
  55 class Processor
  56 {
  57         /**
  58          * Extracts the tag character (#, @, !) from mention links
  59          *
  60          * @param string $body
  61          * @return string
  62          */
  63         protected static function normalizeMentionLinks(string $body): string
  64         {
  65                 return preg_replace('%\[url=([^\[\]]*)]([#@!])(.*?)\[/url]%ism', '$2[url=$1]$3[/url]', $body);
  66         }
  67
  68         /**
  69          * Convert the language array into a language JSON
  70          *
  71          * @param array $languages
  72          * @return string language JSON
  73          */
  74         private static function processLanguages(array $languages)
  75         {
  76                 $codes = array_keys($languages);
  77                 $lang = [];
  78                 foreach ($codes as $code) {
  79                         $lang[$code] = 1;
  80                 }
  81
  82                 if (empty($lang)) {
  83                         return '';
  84                 }
  85
  86                 return json_encode($lang);
  87         }
  88         /**
  89          * Replaces emojis in the body
  90          *
  91          * @param array $emojis
  92          * @param string $body
  93          *
  94          * @return string with replaced emojis
  95          */
  96         private static function replaceEmojis(int $uri_id, $body, array $emojis)
  97         {
  98                 $body = strtr($body,
  99                         array_combine(
 100                                 array_column($emojis, 'name'),
 101                                 array_map(function ($emoji) {
 102                                         return '[emoji=' . $emoji['href'] . ']' . $emoji['name'] . '[/emoji]';
 103                                 }, $emojis)
 104                         )
 105                 );
 106
 107                 // We store the emoji here to be able to avoid storing it in the media
 108                 foreach ($emojis as $emoji) {
 109                         Post\Link::getByLink($uri_id, $emoji['href']);
 110                 }
 111                 return $body;
 112         }
 113
 114         /**
 115          * Store attached media files in the post-media table
 116          *
 117          * @param int $uriid
 118          * @param array $attachment
 119          * @return void
 120          */
 121         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
 122         {
 123                 if (empty($attachment['url'])) {
 124                         return;
 125                 }
 126
 127                 $data = ['uri-id' => $uriid];
 128                 $data['type'] = Post\Media::UNKNOWN;
 129                 $data['url'] = $attachment['url'];
 130                 $data['mimetype'] = $attachment['mediaType'] ?? null;
 131                 $data['height'] = $attachment['height'] ?? null;
 132                 $data['width'] = $attachment['width'] ?? null;
 133                 $data['size'] = $attachment['size'] ?? null;
 134                 $data['preview'] = $attachment['image'] ?? null;
 135                 $data['description'] = $attachment['name'] ?? null;
 136
 137                 Post\Media::insert($data);
 138         }
 139
 140         /**
 141          * Stire attachment data
 142          *
 143          * @param array   $activity
 144          * @param array   $item
 145          */
 146         private static function storeAttachments($activity, $item)
 147         {
 148                 if (empty($activity['attachments'])) {
 149                         return;
 150                 }
 151
 152                 foreach ($activity['attachments'] as $attach) {
 153                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 154                 }
 155         }
 156
 157         /**
 158          * Store attachment data
 159          *
 160          * @param array   $activity
 161          * @param array   $item
 162          */
 163         private static function storeQuestion($activity, $item)
 164         {
 165                 if (empty($activity['question'])) {
 166                         return;
 167                 }
 168                 $question = ['multiple' => $activity['question']['multiple']];
 169
 170                 if (!empty($activity['question']['voters'])) {
 171                         $question['voters'] = $activity['question']['voters'];
 172                 }
 173
 174                 if (!empty($activity['question']['end-time'])) {
 175                         $question['end-time'] = DateTimeFormat::utc($activity['question']['end-time']);
 176                 }
 177
 178                 Post\Question::update($item['uri-id'], $question);
 179
 180                 foreach ($activity['question']['options'] as $key => $option) {
 181                         $option = ['name' => $option['name'], 'replies' => $option['replies']];
 182                         Post\QuestionOption::update($item['uri-id'], $key, $option);
 183                 }
 184
 185                 Logger::debug('Storing incoming question', ['type' => $activity['type'], 'uri-id' => $item['uri-id'], 'question' => $activity['question']]);
 186         }
 187
 188         /**
 189          * Updates a message
 190          *
 191          * @param array $activity Activity array
 192          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 193          */
 194         public static function updateItem($activity)
 195         {
 196                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type'], ['uri' => $activity['id']]);
 197                 if (!DBA::isResult($item)) {
 198                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 199                         $item = self::createItem($activity);
 200                         if (empty($item)) {
 201                                 return;
 202                         }
 203
 204                         self::postItem($activity, $item);
 205                         return;
 206                 }
 207
 208                 $item['changed'] = DateTimeFormat::utcNow();
 209                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 210
 211                 $item = self::processContent($activity, $item);
 212
 213                 self::storeAttachments($activity, $item);
 214                 self::storeQuestion($activity, $item);
 215
 216                 if (empty($item)) {
 217                         return;
 218                 }
 219
 220                 Post\History::add($item['uri-id'], $item);
 221                 Item::update($item, ['uri' => $activity['id']]);
 222
 223                 if ($activity['object_type'] == 'as:Event') {
 224                         $posts = Post::select(['event-id', 'uid'], ["`uri` = ? AND `event-id` > ?", $activity['id'], 0]);
 225                         while ($post = DBA::fetch($posts)) {
 226                                 self::updateEvent($post['event-id'], $activity);
 227                         }
 228                 }
 229         }
 230
 231         /**
 232          * Update an existing event
 233          *
 234          * @param int $event_id
 235          * @param array $activity
 236          */
 237         private static function updateEvent(int $event_id, array $activity)
 238         {
 239                 $event = DBA::selectFirst('event', [], ['id' => $event_id]);
 240
 241                 $event['edited']   = DateTimeFormat::utc($activity['updated']);
 242                 $event['summary']  = HTML::toBBCode($activity['name']);
 243                 $event['desc']     = HTML::toBBCode($activity['content']);
 244                 if (!empty($activity['start-time'])) {
 245                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 246                 }
 247                 if (!empty($activity['end-time'])) {
 248                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 249                 }
 250                 $event['nofinish'] = empty($event['finish']);
 251                 $event['location'] = $activity['location'];
 252
 253                 Logger::info('Updating event', ['uri' => $activity['id'], 'id' => $event_id]);
 254                 Event::store($event);
 255         }
 256
 257         /**
 258          * Prepares data for a message
 259          *
 260          * @param array $activity Activity array
 261          * @return array Internal item
 262          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 263          * @throws \ImagickException
 264          */
 265         public static function createItem($activity)
 266         {
 267                 $item = [];
 268                 $item['verb'] = Activity::POST;
 269                 $item['thr-parent'] = $activity['reply-to-id'];
 270
 271                 if ($activity['reply-to-id'] == $activity['id']) {
 272                         $item['gravity'] = GRAVITY_PARENT;
 273                         $item['object-type'] = Activity\ObjectType::NOTE;
 274                 } else {
 275                         $item['gravity'] = GRAVITY_COMMENT;
 276                         $item['object-type'] = Activity\ObjectType::COMMENT;
 277                 }
 278
 279                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 280                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 281                         self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 282                 }
 283
 284                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 285
 286                 /// @todo What to do with $activity['context']?
 287                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 288                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 289                         return [];
 290                 }
 291
 292                 $item['network'] = Protocol::ACTIVITYPUB;
 293                 $item['author-link'] = $activity['author'];
 294                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 295                 $item['owner-link'] = $activity['actor'];
 296                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 297
 298                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 299                         $item['private'] = Item::UNLISTED;
 300                 } elseif (in_array(0, $activity['receiver'])) {
 301                         $item['private'] = Item::PUBLIC;
 302                 } else {
 303                         $item['private'] = Item::PRIVATE;
 304                 }
 305
 306                 if (!empty($activity['raw'])) {
 307                         $item['source'] = $activity['raw'];
 308                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 309                         $item['conversation-href'] = $activity['context'] ?? '';
 310                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 311
 312                         if (isset($activity['push'])) {
 313                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 314                         }
 315                 }
 316
 317                 if (!empty($activity['from-relay'])) {
 318                         $item['direction'] = Conversation::RELAY;
 319                 }
 320
 321                 if ($activity['object_type'] == 'as:Article') {
 322                         $item['post-type'] = Item::PT_ARTICLE;
 323                 } elseif ($activity['object_type'] == 'as:Audio') {
 324                         $item['post-type'] = Item::PT_AUDIO;
 325                 } elseif ($activity['object_type'] == 'as:Document') {
 326                         $item['post-type'] = Item::PT_DOCUMENT;
 327                 } elseif ($activity['object_type'] == 'as:Event') {
 328                         $item['post-type'] = Item::PT_EVENT;
 329                 } elseif ($activity['object_type'] == 'as:Image') {
 330                         $item['post-type'] = Item::PT_IMAGE;
 331                 } elseif ($activity['object_type'] == 'as:Page') {
 332                         $item['post-type'] = Item::PT_PAGE;
 333                 } elseif ($activity['object_type'] == 'as:Question') {
 334                         $item['post-type'] = Item::PT_POLL;
 335                 } elseif ($activity['object_type'] == 'as:Video') {
 336                         $item['post-type'] = Item::PT_VIDEO;
 337                 } else {
 338                         $item['post-type'] = Item::PT_NOTE;
 339                 }
 340
 341                 $item['isForum'] = false;
 342
 343                 if (!empty($activity['thread-completion'])) {
 344                         if ($activity['thread-completion'] != $item['owner-id']) {
 345                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 346                                 $item['causer-link'] = $actor['url'];
 347                                 $item['causer-id'] = $activity['thread-completion'];
 348                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 349                         } else {
 350                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 351                                 $item['causer-link'] = $item['owner-link'];
 352                                 $item['causer-id']   = $item['owner-id'];
 353                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 354                         }
 355
 356                         $item['owner-link'] = $item['author-link'];
 357                         $item['owner-id'] = $item['author-id'];
 358                 } else {
 359                         $actor = APContact::getByURL($item['owner-link'], false);
 360                         $item['isForum'] = ($actor['type'] == 'Group');
 361                 }
 362
 363                 $item['uri'] = $activity['id'];
 364
 365                 if (empty($activity['published']) || empty($activity['updated'])) {
 366                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 367                 }
 368
 369                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 370                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 371                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 372                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 373
 374                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 375                 if (empty($item['uri-id'])) {
 376                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 377                         return [];
 378                 }
 379
 380                 $item = self::processContent($activity, $item);
 381                 if (empty($item)) {
 382                         Logger::info('Message was not processed');
 383                         return [];
 384                 }
 385
 386                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 387
 388                 self::storeAttachments($activity, $item);
 389                 self::storeQuestion($activity, $item);
 390
 391                 // We received the post via AP, so we set the protocol of the server to AP
 392                 $contact = Contact::getById($item['author-id'], ['gsid']);
 393                 if (!empty($contact['gsid'])) {
 394                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 395                 }
 396
 397                 if ($item['author-id'] != $item['owner-id']) {
 398                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 399                         if (!empty($contact['gsid'])) {
 400                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 401                         }
 402                 }
 403
 404                 return $item;
 405         }
 406
 407         /**
 408          * Delete items
 409          *
 410          * @param array $activity
 411          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 412          * @throws \ImagickException
 413          */
 414         public static function deleteItem($activity)
 415         {
 416                 $owner = Contact::getIdForURL($activity['actor']);
 417
 418                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 419                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 420         }
 421
 422         /**
 423          * Prepare the item array for an activity
 424          *
 425          * @param array $activity Activity array
 426          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 427          * @throws \ImagickException
 428          */
 429         public static function addTag($activity)
 430         {
 431                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 432                         return;
 433                 }
 434
 435                 foreach ($activity['receiver'] as $receiver) {
 436                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 437                         if (!DBA::isResult($item)) {
 438                                 // We don't fetch missing content for this purpose
 439                                 continue;
 440                         }
 441
 442                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 443                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 444                                 continue;
 445                         }
 446
 447                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 448                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 449                 }
 450         }
 451
 452         /**
 453          * Prepare the item array for an activity
 454          *
 455          * @param array  $activity Activity array
 456          * @param string $verb     Activity verb
 457          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 458          * @throws \ImagickException
 459          */
 460         public static function createActivity($activity, $verb)
 461         {
 462                 $item = self::createItem($activity);
 463                 if (empty($item)) {
 464                         return;
 465                 }
 466
 467                 $item['verb'] = $verb;
 468                 $item['thr-parent'] = $activity['object_id'];
 469                 $item['gravity'] = GRAVITY_ACTIVITY;
 470                 unset($item['post-type']);
 471                 $item['object-type'] = Activity\ObjectType::NOTE;
 472
 473                 if (!empty($activity['content'])) {
 474                         $item['body'] = HTML::toBBCode($activity['content']);
 475                 }
 476
 477                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 478
 479                 self::postItem($activity, $item);
 480         }
 481
 482         /**
 483          * Fetch the Uri-Id of a post for the "featured" collection
 484          *
 485          * @param array $activity
 486          * @return null|int
 487          */
 488         private static function getUriIdForFeaturedCollection(array $activity)
 489         {
 490                 $actor = APContact::getByURL($activity['actor']);
 491                 if (empty($actor)) {
 492                         return null;
 493                 }
 494
 495                 // Refetch the account when the "featured" collection is missing.
 496                 // This can be removed in a future version (end of 2022 should be good).
 497                 if (empty($actor['featured'])) {
 498                         $actor = APContact::getByURL($activity['actor'], true);
 499                         if (empty($actor)) {
 500                                 return null;
 501                         }
 502                 }
 503
 504                 if ($activity['target_id'] != $actor['featured']) {
 505                         return null;
 506                 }
 507
 508                 $id = Contact::getIdForURL($activity['actor']);
 509                 if (empty($id)) {
 510                         return null;
 511                 }
 512
 513                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id'], 'author-id' => $id]);
 514                 if (!empty($parent['uri-id'])) {
 515                         return $parent['uri-id'];
 516                 }
 517
 518                 return null;
 519         }
 520
 521         /**
 522          * Add a post to the "Featured" collection
 523          *
 524          * @param array $activity
 525          */
 526         public static function addToFeaturedCollection(array $activity)
 527         {
 528                 $uriid = self::getUriIdForFeaturedCollection($activity);
 529                 if (empty($uriid)) {
 530                         return;
 531                 }
 532
 533                 Logger::debug('Add post to featured collection', ['uri-id' => $uriid]);
 534
 535                 Post\Collection::add($uriid, Post\Collection::FEATURED);
 536         }
 537
 538         /**
 539          * Remove a post to the "Featured" collection
 540          *
 541          * @param array $activity
 542          */
 543         public static function removeFromFeaturedCollection(array $activity)
 544         {
 545                 $uriid = self::getUriIdForFeaturedCollection($activity);
 546                 if (empty($uriid)) {
 547                         return;
 548                 }
 549
 550                 Logger::debug('Remove post from featured collection', ['uri-id' => $uriid]);
 551
 552                 Post\Collection::remove($uriid, Post\Collection::FEATURED);
 553         }
 554
 555         /**
 556          * Create an event
 557          *
 558          * @param array $activity Activity array
 559          * @param array $item
 560          *
 561          * @return int event id
 562          * @throws \Exception
 563          */
 564         public static function createEvent($activity, $item)
 565         {
 566                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 567                 $event['desc']      = HTML::toBBCode($activity['content']);
 568                 if (!empty($activity['start-time'])) {
 569                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 570                 }
 571                 if (!empty($activity['end-time'])) {
 572                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 573                 }
 574                 $event['nofinish']  = empty($event['finish']);
 575                 $event['location']  = $activity['location'];
 576                 $event['cid']       = $item['contact-id'];
 577                 $event['uid']       = $item['uid'];
 578                 $event['uri']       = $item['uri'];
 579                 $event['edited']    = $item['edited'];
 580                 $event['private']   = $item['private'];
 581                 $event['guid']      = $item['guid'];
 582                 $event['plink']     = $item['plink'];
 583                 $event['network']   = $item['network'];
 584                 $event['protocol']  = $item['protocol'];
 585                 $event['direction'] = $item['direction'];
 586                 $event['source']    = $item['source'];
 587
 588                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 589                 if (DBA::isResult($ev)) {
 590                         $event['id'] = $ev['id'];
 591                 }
 592
 593                 $event_id = Event::store($event);
 594
 595                 Logger::info('Event was stored', ['id' => $event_id]);
 596
 597                 return $event_id;
 598         }
 599
 600         /**
 601          * Process the content
 602          *
 603          * @param array $activity Activity array
 604          * @param array $item
 605          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 606          * @throws \Exception
 607          */
 608         private static function processContent($activity, $item)
 609         {
 610                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 611                         $item['title'] = strip_tags($activity['name']);
 612                         $content = Markdown::toBBCode($activity['content']);
 613                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 614                         $item['title'] = $activity['name'];
 615                         $content = $activity['content'];
 616                 } else {
 617                         // By default assume "text/html"
 618                         $item['title'] = HTML::toBBCode($activity['name']);
 619                         $content = HTML::toBBCode($activity['content']);
 620                 }
 621
 622                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 623
 624                 if (!empty($activity['languages'])) {
 625                         $item['language'] = self::processLanguages($activity['languages']);
 626                 }
 627
 628                 if (!empty($activity['emojis'])) {
 629                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 630                 }
 631
 632                 $content = self::addMentionLinks($content, $activity['tags']);
 633
 634                 if (!empty($activity['source'])) {
 635                         $item['body'] = $activity['source'];
 636                         $item['raw-body'] = $content;
 637                         $item['body'] = Item::improveSharedDataInBody($item);
 638                 } else {
 639                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 640                                 $item_private = !in_array(0, $activity['item_receiver']);
 641                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 642                                 if (!DBA::isResult($parent)) {
 643                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 644                                         return false;
 645                                 }
 646                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 647                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 648                                         return false;
 649                                 }
 650
 651                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 652                         }
 653                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 654                         $item['raw-body'] = $item['body'] = $content;
 655                 }
 656
 657                 self::storeFromBody($item);
 658                 self::storeTags($item['uri-id'], $activity['tags']);
 659
 660                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 661
 662                 $item['location'] = $activity['location'];
 663
 664                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 665                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 666                 }
 667
 668                 $item['app'] = $activity['generator'];
 669
 670                 return $item;
 671         }
 672
 673         /**
 674          * Store hashtags and mentions
 675          *
 676          * @param array $item
 677          */
 678         private static function storeFromBody(array $item)
 679         {
 680                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 681                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 682
 683                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 684         }
 685
 686         /**
 687          * Generate a GUID out of an URL of an ActivityPub post.
 688          *
 689          * @param string $url message URL
 690          * @return string with GUID
 691          */
 692         private static function getGUIDByURL(string $url)
 693         {
 694                 $parsed = parse_url($url);
 695
 696                 $host_hash = hash('crc32', $parsed['host']);
 697
 698                 unset($parsed["scheme"]);
 699                 unset($parsed["host"]);
 700
 701                 $path = implode("/", $parsed);
 702
 703                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 704         }
 705
 706         /**
 707          * Checks if an incoming message is wanted
 708          *
 709          * @param array $activity
 710          * @param array $item
 711          * @return boolean Is the message wanted?
 712          */
 713         private static function isSolicitedMessage(array $activity, array $item)
 714         {
 715                 // The checks are split to improve the support when searching why a message was accepted.
 716                 if (count($activity['receiver']) != 1) {
 717                         // The message has more than one receiver, so it is wanted.
 718                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 719                         return true;
 720                 }
 721
 722                 if ($item['private'] == Item::PRIVATE) {
 723                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 724                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 725                         return true;
 726                 }
 727
 728                 if (!empty($activity['from-relay'])) {
 729                         // We check relay posts at another place. When it arrived here, the message is already checked.
 730                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 731                         return true;
 732                 }
 733
 734                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
 735                         // Manual completions and completions caused by reshares are allowed without any further checks.
 736                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 737                         return true;
 738                 }
 739
 740                 if ($item['gravity'] != GRAVITY_PARENT) {
 741                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 742                         // This can possibly be improved in the future.
 743                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 744                         return true;
 745                 }
 746
 747                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 748                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB)) {
 749                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 750                         return true;
 751                 } else {
 752                         return false;
 753                 }
 754         }
 755
 756         /**
 757          * Creates an item post
 758          *
 759          * @param array $activity Activity data
 760          * @param array $item     item array
 761          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 762          * @throws \ImagickException
 763          */
 764         public static function postItem(array $activity, array $item)
 765         {
 766                 if (empty($item)) {
 767                         return;
 768                 }
 769
 770                 $stored = false;
 771                 ksort($activity['receiver']);
 772
 773                 if (!self::isSolicitedMessage($activity, $item)) {
 774                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
 775                         return;
 776                 }
 777
 778                 foreach ($activity['receiver'] as $receiver) {
 779                         if ($receiver == -1) {
 780                                 continue;
 781                         }
 782
 783                         $item['uid'] = $receiver;
 784
 785                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 786                         switch($type) {
 787                                 case Receiver::TARGET_TO:
 788                                         $item['post-reason'] = Item::PR_TO;
 789                                         break;
 790                                 case Receiver::TARGET_CC:
 791                                         $item['post-reason'] = Item::PR_CC;
 792                                         break;
 793                                 case Receiver::TARGET_BTO:
 794                                         $item['post-reason'] = Item::PR_BTO;
 795                                         break;
 796                                 case Receiver::TARGET_BCC:
 797                                         $item['post-reason'] = Item::PR_BCC;
 798                                         break;
 799                                 case Receiver::TARGET_FOLLOWER:
 800                                         $item['post-reason'] = Item::PR_FOLLOWER;
 801                                         break;
 802                                 case Receiver::TARGET_ANSWER:
 803                                         $item['post-reason'] = Item::PR_COMMENT;
 804                                         break;
 805                                 case Receiver::TARGET_GLOBAL:
 806                                         $item['post-reason'] = Item::PR_GLOBAL;
 807                                         break;
 808                                 default:
 809                                         $item['post-reason'] = Item::PR_NONE;
 810                         }
 811
 812                         if (!empty($activity['from-relay'])) {
 813                                 $item['post-reason'] = Item::PR_RELAY;
 814                         } elseif (!empty($activity['thread-completion'])) {
 815                                 $item['post-reason'] = Item::PR_FETCHED;
 816                         }
 817
 818                         if ($item['isForum'] ?? false) {
 819                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 820                         } else {
 821                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 822                         }
 823
 824                         if (($receiver != 0) && empty($item['contact-id'])) {
 825                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 826                         }
 827
 828                         if (!empty($activity['directmessage'])) {
 829                                 self::postMail($activity, $item);
 830                                 continue;
 831                         }
 832
 833                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 834                                 if ($item['post-reason'] == Item::PR_BCC) {
 835                                         Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 836                                         continue;
 837                                 }
 838
 839                                 if (
 840                                         !empty($activity['thread-children-type'])
 841                                         && in_array($activity['thread-children-type'], Receiver::ACTIVITY_TYPES)
 842                                         && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE
 843                                 ) {
 844                                         Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
 845                                                 ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
 846                                         continue;
 847                                 }
 848                         }
 849
 850                         $is_forum = false;
 851
 852                         if ($receiver != 0) {
 853                                 $user = User::getById($receiver, ['account-type']);
 854                                 if (!empty($user['account-type'])) {
 855                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 856                                 }
 857                         }
 858
 859                         if (!$is_forum && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 860                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 861
 862                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 863                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 864                                 }
 865
 866                                 if ($skip) {
 867                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 868                                         continue;
 869                                 }
 870
 871                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 872                         }
 873
 874                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 875                                 $event_id = self::createEvent($activity, $item);
 876
 877                                 $item = Event::getItemArrayForImportedId($event_id, $item);
 878                         }
 879
 880                         $item_id = Item::insert($item);
 881                         if ($item_id) {
 882                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 883                         } else {
 884                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 885                         }
 886
 887                         if ($item['uid'] == 0) {
 888                                 $stored = $item_id;
 889                         }
 890                 }
 891
 892                 // Store send a follow request for every reshare - but only when the item had been stored
 893                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 894                         $author = APContact::getByURL($item['owner-link'], false);
 895                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 896                         if ($author['type'] != 'Group') {
 897                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 898                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 899                         }
 900                 }
 901         }
 902
 903         /**
 904          * Store tags and mentions into the tag table
 905          *
 906          * @param integer $uriid
 907          * @param array $tags
 908          */
 909         private static function storeTags(int $uriid, array $tags = null)
 910         {
 911                 foreach ($tags as $tag) {
 912                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 913                                 continue;
 914                         }
 915
 916                         $hash = substr($tag['name'], 0, 1);
 917
 918                         if ($tag['type'] == 'Mention') {
 919                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 920                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 921                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 922                                         $tag['name'] = substr($tag['name'], 1);
 923                                 }
 924                                 $type = Tag::IMPLICIT_MENTION;
 925
 926                                 if (!empty($tag['href'])) {
 927                                         $apcontact = APContact::getByURL($tag['href']);
 928                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 929                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 930                                         }
 931                                 }
 932                         } elseif ($tag['type'] == 'Hashtag') {
 933                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 934                                         $tag['name'] = substr($tag['name'], 1);
 935                                 }
 936                                 $type = Tag::HASHTAG;
 937                         }
 938
 939                         if (empty($tag['name'])) {
 940                                 continue;
 941                         }
 942
 943                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 944                 }
 945         }
 946
 947         public static function storeReceivers(int $uriid, array $receivers)
 948         {
 949                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
 950                         if (!empty($receivers[$element])) {
 951                                 foreach ($receivers[$element] as $receiver) {
 952                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
 953                                                 $name = Receiver::PUBLIC_COLLECTION;
 954                                         } else {
 955                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
 956                                         }
 957
 958                                         $target = Tag::getTargetType($receiver);
 959                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
 960                                         Tag::store($uriid, $type, $name, $receiver, $target);
 961                                 }
 962                         }
 963                 }
 964         }
 965
 966         /**
 967          * Creates an mail post
 968          *
 969          * @param array $activity Activity data
 970          * @param array $item     item array
 971          * @return int|bool New mail table row id or false on error
 972          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 973          */
 974         private static function postMail($activity, $item)
 975         {
 976                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 977                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 978                         return false;
 979                 }
 980
 981                 Logger::info('Direct Message', $item);
 982
 983                 $msg = [];
 984                 $msg['uid'] = $item['uid'];
 985
 986                 $msg['contact-id'] = $item['contact-id'];
 987
 988                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 989                 $msg['from-name'] = $contact['name'];
 990                 $msg['from-url'] = $contact['url'];
 991                 $msg['from-photo'] = $contact['photo'];
 992
 993                 $msg['uri'] = $item['uri'];
 994                 $msg['created'] = $item['created'];
 995
 996                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 997                 if (DBA::isResult($parent)) {
 998                         $msg['parent-uri'] = $parent['parent-uri'];
 999                         $msg['title'] = $parent['title'];
1000                 } else {
1001                         $msg['parent-uri'] = $item['thr-parent'];
1002
1003                         if (!empty($item['title'])) {
1004                                 $msg['title'] = $item['title'];
1005                         } elseif (!empty($item['content-warning'])) {
1006                                 $msg['title'] = $item['content-warning'];
1007                         } else {
1008                                 // Trying to generate a title out of the body
1009                                 $title = $item['body'];
1010
1011                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1012                                         $title = $matches[3];
1013                                 }
1014
1015                                 $title = trim(BBCode::toPlaintext($title));
1016
1017                                 if (strlen($title) > 20) {
1018                                         $title = substr($title, 0, 20) . '...';
1019                                 }
1020
1021                                 $msg['title'] = $title;
1022                         }
1023                 }
1024                 $msg['body'] = $item['body'];
1025
1026                 return Mail::insert($msg);
1027         }
1028
1029         /**
1030          * Fetch featured posts from a contact with the given url
1031          *
1032          * @param string $url
1033          * @return void
1034          */
1035         public static function fetchFeaturedPosts(string $url)
1036         {
1037                 Logger::info('Fetch featured posts', ['contact' => $url]);
1038
1039                 $apcontact = APContact::getByURL($url);
1040                 if (empty($apcontact['featured'])) {
1041                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1042                         return;
1043                 }
1044
1045                 $pcid = Contact::getIdForURL($url, 0, false);
1046                 if (empty($pcid)) {
1047                         Logger::info('Contact not found', ['contact' => $url]);
1048                         return;
1049                 }
1050
1051                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1052                 if (!empty($posts)) {
1053                         $old_featured = array_column($posts, 'uri-id');
1054                 } else {
1055                         $old_featured = [];
1056                 }
1057
1058                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1059                 if (empty($featured)) {
1060                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1061
1062                         foreach ($old_featured as $uri_id) {
1063                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1064                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1065                         }
1066                         return;
1067                 }
1068
1069                 $new = 0;
1070                 $old = 0;
1071
1072                 foreach ($featured as $post) {
1073                         if (empty($post['id'])) {
1074                                 continue;
1075                         }
1076                         $id = Item::fetchByLink($post['id']);
1077                         if (!empty($id)) {
1078                                 $item = Post::selectFirst(['uri-id', 'featured'], ['id' => $id]);
1079                                 if (!empty($item['uri-id'])) {
1080                                         if (!$item['featured']) {
1081                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED);
1082                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1083                                                 $new++;
1084                                         } else {
1085                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1086                                                 $old++;
1087                                         }
1088
1089                                         $index = array_search($item['uri-id'], $old_featured);
1090                                         if (!($index === false)) {
1091                                                 unset($old_featured[$index]);
1092                                         }
1093                                 }
1094                         }
1095                 }
1096
1097                 foreach ($old_featured as $uri_id) {
1098                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1099                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1100                 }
1101
1102                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1103         }
1104
1105         /**
1106          * Fetches missing posts
1107          *
1108          * @param string $url         message URL
1109          * @param array  $child       activity array with the child of this message
1110          * @param string $relay_actor Relay actor
1111          * @param int    $completion  Completion mode, see Receiver::COMPLETION_*
1112          * @return string fetched message URL
1113          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1114          */
1115         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL)
1116         {
1117                 if (!empty($child['receiver'])) {
1118                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
1119                 } else {
1120                         $uid = 0;
1121                 }
1122
1123                 $object = ActivityPub::fetchContent($url, $uid);
1124                 if (empty($object)) {
1125                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url]);
1126                         return '';
1127                 }
1128
1129                 if (empty($object['id'])) {
1130                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1131                         return '';
1132                 }
1133
1134                 if (!empty($object['actor'])) {
1135                         $object_actor = $object['actor'];
1136                 } elseif (!empty($object['attributedTo'])) {
1137                         $object_actor = $object['attributedTo'];
1138                         if (is_array($object_actor)) {
1139                                 $compacted = JsonLD::compact($object);
1140                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1141                         }
1142                 } else {
1143                         // Shouldn't happen
1144                         $object_actor = '';
1145                 }
1146
1147                 $signer = [$object_actor];
1148
1149                 if (!empty($child['author'])) {
1150                         $actor = $child['author'];
1151                         $signer[] = $actor;
1152                 } else {
1153                         $actor = $object_actor;
1154                 }
1155
1156                 if (!empty($object['published'])) {
1157                         $published = $object['published'];
1158                 } elseif (!empty($child['published'])) {
1159                         $published = $child['published'];
1160                 } else {
1161                         $published = DateTimeFormat::utcNow();
1162                 }
1163
1164                 $activity = [];
1165                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1166                 unset($object['@context']);
1167                 $activity['id'] = $object['id'];
1168                 $activity['to'] = $object['to'] ?? [];
1169                 $activity['cc'] = $object['cc'] ?? [];
1170                 $activity['actor'] = $actor;
1171                 $activity['object'] = $object;
1172                 $activity['published'] = $published;
1173                 $activity['type'] = 'Create';
1174
1175                 $ldactivity = JsonLD::compact($activity);
1176
1177                 if (!empty($relay_actor)) {
1178                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
1179                         $ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
1180                 } elseif (!empty($child['thread-completion'])) {
1181                         $ldactivity['thread-completion'] = $child['thread-completion'];
1182                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1183                 } else {
1184                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
1185                         $ldactivity['completion-mode']   = $completion;
1186                 }
1187
1188                 if (!empty($child['type'])) {
1189                         $ldactivity['thread-children-type'] = $child['type'];
1190                 }
1191
1192                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
1193                         return '';
1194                 }
1195
1196                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
1197
1198                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
1199
1200                 return $activity['id'];
1201         }
1202
1203         /**
1204          * Test if incoming relay messages should be accepted
1205          *
1206          * @param array $activity activity array
1207          * @param string $id      object ID
1208          * @return boolean true if message is accepted
1209          */
1210         private static function acceptIncomingMessage(array $activity, string $id)
1211         {
1212                 if (empty($activity['as:object'])) {
1213                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1214                         return true;
1215                 }
1216
1217                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1218                 $uriid = ItemURI::getIdByURI($replyto);
1219                 if (Post::exists(['uri-id' => $uriid])) {
1220                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1221                         return true;
1222                 }
1223
1224                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1225                 $authorid = Contact::getIdForURL($attributed_to);
1226
1227                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value'));
1228
1229                 $messageTags = [];
1230                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1231                 if (!empty($tags)) {
1232                         foreach ($tags as $tag) {
1233                                 if ($tag['type'] != 'Hashtag') {
1234                                         continue;
1235                                 }
1236                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1237                         }
1238                 }
1239
1240                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
1241         }
1242
1243         /**
1244          * perform a "follow" request
1245          *
1246          * @param array $activity
1247          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1248          * @throws \ImagickException
1249          */
1250         public static function followUser($activity)
1251         {
1252                 $uid = User::getIdForURL($activity['object_id']);
1253                 if (empty($uid)) {
1254                         return;
1255                 }
1256
1257                 $owner = User::getOwnerDataById($uid);
1258                 if (empty($owner)) {
1259                         return;
1260                 }
1261
1262                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1263                 if (!empty($cid)) {
1264                         self::switchContact($cid);
1265                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1266                 }
1267
1268                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
1269                         'author-link' => $activity['actor']];
1270
1271                 // Ensure that the contact has got the right network type
1272                 self::switchContact($item['author-id']);
1273
1274                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1275                 if ($result === true) {
1276                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1277                 }
1278
1279                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1280                 if (empty($cid)) {
1281                         return;
1282                 }
1283
1284                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1285                         self::transmitPendingEvents($cid, $owner['uid']);
1286                 }
1287
1288                 if (empty($contact)) {
1289                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1290                 }
1291
1292                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1293         }
1294
1295         /**
1296          * Transmit pending events to the new follower
1297          *
1298          * @param integer $cid
1299          * @param integer $uid
1300          * @return void
1301          */
1302         private static function transmitPendingEvents(int $cid, int $uid)
1303         {
1304                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1305                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1306
1307                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1308                 while ($event = DBA::fetch($events)) {
1309                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1310                         if (empty($post)) {
1311                                 continue;
1312                         }
1313                         if (DI::config()->get('system', 'bulk_delivery')) {
1314                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1315                                 Worker::add(PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1316                         } else {
1317                                 Worker::add(PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1318                         }
1319                 }
1320         }
1321
1322         /**
1323          * Update the given profile
1324          *
1325          * @param array $activity
1326          * @throws \Exception
1327          */
1328         public static function updatePerson($activity)
1329         {
1330                 if (empty($activity['object_id'])) {
1331                         return;
1332                 }
1333
1334                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1335                 Contact::updateFromProbeByURL($activity['object_id']);
1336         }
1337
1338         /**
1339          * Delete the given profile
1340          *
1341          * @param array $activity
1342          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1343          */
1344         public static function deletePerson($activity)
1345         {
1346                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1347                         Logger::info('Empty object id or actor.');
1348                         return;
1349                 }
1350
1351                 if ($activity['object_id'] != $activity['actor']) {
1352                         Logger::info('Object id does not match actor.');
1353                         return;
1354                 }
1355
1356                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1357                 while ($contact = DBA::fetch($contacts)) {
1358                         Contact::remove($contact['id']);
1359                 }
1360                 DBA::close($contacts);
1361
1362                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1363         }
1364
1365         /**
1366          * Blocks the user by the contact
1367          *
1368          * @param array $activity
1369          * @throws \Exception
1370          */
1371         public static function blockAccount($activity)
1372         {
1373                 $cid = Contact::getIdForURL($activity['actor']);
1374                 if (empty($cid)) {
1375                         return;
1376                 }
1377
1378                 $uid = User::getIdForURL($activity['object_id']);
1379                 if (empty($uid)) {
1380                         return;
1381                 }
1382
1383                 Contact\User::setIsBlocked($cid, $uid, true);
1384
1385                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1386         }
1387
1388         /**
1389          * Unblocks the user by the contact
1390          *
1391          * @param array $activity
1392          * @throws \Exception
1393          */
1394         public static function unblockAccount($activity)
1395         {
1396                 $cid = Contact::getIdForURL($activity['actor']);
1397                 if (empty($cid)) {
1398                         return;
1399                 }
1400
1401                 $uid = User::getIdForURL($activity['object_object']);
1402                 if (empty($uid)) {
1403                         return;
1404                 }
1405
1406                 Contact\User::setIsBlocked($cid, $uid, false);
1407
1408                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1409         }
1410
1411         /**
1412          * Accept a follow request
1413          *
1414          * @param array $activity
1415          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1416          * @throws \ImagickException
1417          */
1418         public static function acceptFollowUser($activity)
1419         {
1420                 $uid = User::getIdForURL($activity['object_actor']);
1421                 if (empty($uid)) {
1422                         return;
1423                 }
1424
1425                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1426                 if (empty($cid)) {
1427                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1428                         return;
1429                 }
1430
1431                 self::switchContact($cid);
1432
1433                 $fields = ['pending' => false];
1434
1435                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1436                 if ($contact['rel'] == Contact::FOLLOWER) {
1437                         $fields['rel'] = Contact::FRIEND;
1438                 }
1439
1440                 $condition = ['id' => $cid];
1441                 Contact::update($fields, $condition);
1442                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1443         }
1444
1445         /**
1446          * Reject a follow request
1447          *
1448          * @param array $activity
1449          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1450          * @throws \ImagickException
1451          */
1452         public static function rejectFollowUser($activity)
1453         {
1454                 $uid = User::getIdForURL($activity['object_actor']);
1455                 if (empty($uid)) {
1456                         return;
1457                 }
1458
1459                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1460                 if (empty($cid)) {
1461                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1462                         return;
1463                 }
1464
1465                 self::switchContact($cid);
1466
1467                 $contact = Contact::getById($cid, ['rel']);
1468                 if ($contact['rel'] == Contact::SHARING) {
1469                         Contact::remove($cid);
1470                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1471                 } elseif ($contact['rel'] == Contact::FRIEND) {
1472                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1473                 } else {
1474                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1475                 }
1476         }
1477
1478         /**
1479          * Undo activity like "like" or "dislike"
1480          *
1481          * @param array $activity
1482          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1483          * @throws \ImagickException
1484          */
1485         public static function undoActivity($activity)
1486         {
1487                 if (empty($activity['object_id'])) {
1488                         return;
1489                 }
1490
1491                 if (empty($activity['object_actor'])) {
1492                         return;
1493                 }
1494
1495                 $author_id = Contact::getIdForURL($activity['object_actor']);
1496                 if (empty($author_id)) {
1497                         return;
1498                 }
1499
1500                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1501         }
1502
1503         /**
1504          * Activity to remove a follower
1505          *
1506          * @param array $activity
1507          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1508          * @throws \ImagickException
1509          */
1510         public static function undoFollowUser($activity)
1511         {
1512                 $uid = User::getIdForURL($activity['object_object']);
1513                 if (empty($uid)) {
1514                         return;
1515                 }
1516
1517                 $owner = User::getOwnerDataById($uid);
1518                 if (empty($owner)) {
1519                         return;
1520                 }
1521
1522                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1523                 if (empty($cid)) {
1524                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1525                         return;
1526                 }
1527
1528                 self::switchContact($cid);
1529
1530                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1531                 if (!DBA::isResult($contact)) {
1532                         return;
1533                 }
1534
1535                 Contact::removeFollower($contact);
1536                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1537         }
1538
1539         /**
1540          * Switches a contact to AP if needed
1541          *
1542          * @param integer $cid Contact ID
1543          * @throws \Exception
1544          */
1545         private static function switchContact($cid)
1546         {
1547                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1548                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1549                         return;
1550                 }
1551
1552                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1553                 Contact::updateFromProbe($cid);
1554         }
1555
1556         /**
1557          * Collects implicit mentions like:
1558          * - the author of the parent item
1559          * - all the mentioned conversants in the parent item
1560          *
1561          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1562          * @return array
1563          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1564          */
1565         private static function getImplicitMentionList(array $parent)
1566         {
1567                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1568
1569                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1570
1571                 $implicit_mentions = [];
1572                 if (empty($parent_author['url'])) {
1573                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1574                 } else {
1575                         $implicit_mentions[] = $parent_author['url'];
1576                         $implicit_mentions[] = $parent_author['nurl'];
1577                         $implicit_mentions[] = $parent_author['alias'];
1578                 }
1579
1580                 if (!empty($parent['alias'])) {
1581                         $implicit_mentions[] = $parent['alias'];
1582                 }
1583
1584                 foreach ($parent_terms as $term) {
1585                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1586                         if (!empty($contact['url'])) {
1587                                 $implicit_mentions[] = $contact['url'];
1588                                 $implicit_mentions[] = $contact['nurl'];
1589                                 $implicit_mentions[] = $contact['alias'];
1590                         }
1591                 }
1592
1593                 return $implicit_mentions;
1594         }
1595
1596         /**
1597          * Strips from the body prepended implicit mentions
1598          *
1599          * @param string $body
1600          * @param array $parent
1601          * @return string
1602          */
1603         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1604         {
1605                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1606                         return $body;
1607                 }
1608
1609                 $potential_mentions = self::getImplicitMentionList($parent);
1610
1611                 $kept_mentions = [];
1612
1613                 // Extract one prepended mention at a time from the body
1614                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1615                         if (!in_array($matches[2], $potential_mentions)) {
1616                                 $kept_mentions[] = $matches[1];
1617                         }
1618
1619                         $body = $matches[3];
1620                 }
1621
1622                 // Re-appending the kept mentions to the body after extraction
1623                 $kept_mentions[] = $body;
1624
1625                 return implode('', $kept_mentions);
1626         }
1627
1628         /**
1629          * Adds links to string mentions
1630          *
1631          * @param string $body
1632          * @param array  $tags
1633          * @return string
1634          */
1635         protected static function addMentionLinks(string $body, array $tags): string
1636         {
1637                 // This prevents links to be added again to Pleroma-style mention links
1638                 $body = self::normalizeMentionLinks($body);
1639
1640                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1641                         foreach ($tags as $tag) {
1642                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1643                                         continue;
1644                                 }
1645
1646                                 $hash = substr($tag['name'], 0, 1);
1647                                 $name = substr($tag['name'], 1);
1648                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1649                                         $hash = '';
1650                                         $name = $tag['name'];
1651                                 }
1652
1653                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1654                         }
1655
1656                         return $body;
1657                 });
1658
1659                 return $body;
1660         }
1661 }