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'];
 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          * Updates a message
 157          *
 158          * @param array $activity Activity array
 159          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 160          */
 161         public static function updateItem($activity)
 162         {
 163                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type'], ['uri' => $activity['id']]);
 164                 if (!DBA::isResult($item)) {
 165                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 166                         $item = self::createItem($activity);
 167                         self::postItem($activity, $item);
 168                         return;
 169                 }
 170
 171                 $item['changed'] = DateTimeFormat::utcNow();
 172                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 173
 174                 $item = self::processContent($activity, $item);
 175
 176                 self::storeAttachments($activity, $item);
 177
 178                 if (empty($item)) {
 179                         return;
 180                 }
 181
 182                 Item::update($item, ['uri' => $activity['id']]);
 183         }
 184
 185         /**
 186          * Prepares data for a message
 187          *
 188          * @param array $activity Activity array
 189          * @return array Internal item
 190          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 191          * @throws \ImagickException
 192          */
 193         public static function createItem($activity)
 194         {
 195                 $item = [];
 196                 $item['verb'] = Activity::POST;
 197                 $item['thr-parent'] = $activity['reply-to-id'];
 198
 199                 if ($activity['reply-to-id'] == $activity['id']) {
 200                         $item['gravity'] = GRAVITY_PARENT;
 201                         $item['object-type'] = Activity\ObjectType::NOTE;
 202                 } else {
 203                         $item['gravity'] = GRAVITY_COMMENT;
 204                         $item['object-type'] = Activity\ObjectType::COMMENT;
 205                 }
 206
 207                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 208                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 209                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 210                 }
 211
 212                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 213
 214                 /// @todo What to do with $activity['context']?
 215                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 216                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 217                         return [];
 218                 }
 219
 220                 $item['network'] = Protocol::ACTIVITYPUB;
 221                 $item['author-link'] = $activity['author'];
 222                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 223                 $item['owner-link'] = $activity['actor'];
 224                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 225
 226                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 227                         $item['private'] = Item::UNLISTED;
 228                 } elseif (in_array(0, $activity['receiver'])) {
 229                         $item['private'] = Item::PUBLIC;
 230                 } else {
 231                         $item['private'] = Item::PRIVATE;
 232                 }
 233
 234                 if (!empty($activity['raw'])) {
 235                         $item['source'] = $activity['raw'];
 236                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 237                         $item['conversation-href'] = $activity['context'] ?? '';
 238                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 239
 240                         if (isset($activity['push'])) {
 241                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 242                         }
 243                 }
 244
 245                 if (!empty($activity['from-relay'])) {
 246                         $item['direction'] = Conversation::RELAY;
 247                 }
 248
 249                 if ($activity['object_type'] == 'as:Article') {
 250                         $item['post-type'] = Item::PT_ARTICLE;
 251                 } elseif ($activity['object_type'] == 'as:Audio') {
 252                         $item['post-type'] = Item::PT_AUDIO;
 253                 } elseif ($activity['object_type'] == 'as:Document') {
 254                         $item['post-type'] = Item::PT_DOCUMENT;
 255                 } elseif ($activity['object_type'] == 'as:Event') {
 256                         $item['post-type'] = Item::PT_EVENT;
 257                 } elseif ($activity['object_type'] == 'as:Image') {
 258                         $item['post-type'] = Item::PT_IMAGE;
 259                 } elseif ($activity['object_type'] == 'as:Page') {
 260                         $item['post-type'] = Item::PT_PAGE;
 261                 } elseif ($activity['object_type'] == 'as:Question') {
 262                         $item['post-type'] = Item::PT_POLL;
 263                 } elseif ($activity['object_type'] == 'as:Video') {
 264                         $item['post-type'] = Item::PT_VIDEO;
 265                 } else {
 266                         $item['post-type'] = Item::PT_NOTE;
 267                 }
 268
 269                 $item['isForum'] = false;
 270
 271                 if (!empty($activity['thread-completion'])) {
 272                         if ($activity['thread-completion'] != $item['owner-id']) {
 273                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 274                                 $item['causer-link'] = $actor['url'];
 275                                 $item['causer-id'] = $activity['thread-completion'];
 276                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 277                         } else {
 278                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 279                                 $item['causer-link'] = $item['owner-link'];
 280                                 $item['causer-id'] = $item['owner-id'];
 281                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 282                         }
 283
 284                         $item['owner-link'] = $item['author-link'];
 285                         $item['owner-id'] = $item['author-id'];
 286                 } else {
 287                         $actor = APContact::getByURL($item['owner-link'], false);
 288                         $item['isForum'] = ($actor['type'] == 'Group');
 289                 }
 290
 291                 $item['uri'] = $activity['id'];
 292
 293                 if (empty($activity['published']) || empty($activity['updated'])) {
 294                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 295                 }
 296
 297                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 298                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 299                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 300                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 301
 302                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 303                 if (empty($item['uri-id'])) {
 304                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 305                         return [];
 306                 }
 307
 308                 $item = self::processContent($activity, $item);
 309                 if (empty($item)) {
 310                         Logger::info('Message was not processed');
 311                         return [];
 312                 }
 313
 314                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 315
 316                 self::storeAttachments($activity, $item);
 317
 318                 // We received the post via AP, so we set the protocol of the server to AP
 319                 $contact = Contact::getById($item['author-id'], ['gsid']);
 320                 if (!empty($contact['gsid'])) {
 321                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 322                 }
 323
 324                 if ($item['author-id'] != $item['owner-id']) {
 325                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 326                         if (!empty($contact['gsid'])) {
 327                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 328                         }
 329                 }
 330
 331                 return $item;
 332         }
 333
 334         /**
 335          * Delete items
 336          *
 337          * @param array $activity
 338          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 339          * @throws \ImagickException
 340          */
 341         public static function deleteItem($activity)
 342         {
 343                 $owner = Contact::getIdForURL($activity['actor']);
 344
 345                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 346                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 347         }
 348
 349         /**
 350          * Prepare the item array for an activity
 351          *
 352          * @param array $activity Activity array
 353          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 354          * @throws \ImagickException
 355          */
 356         public static function addTag($activity)
 357         {
 358                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 359                         return;
 360                 }
 361
 362                 foreach ($activity['receiver'] as $receiver) {
 363                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 364                         if (!DBA::isResult($item)) {
 365                                 // We don't fetch missing content for this purpose
 366                                 continue;
 367                         }
 368
 369                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 370                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 371                                 continue;
 372                         }
 373
 374                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 375                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 376                 }
 377         }
 378
 379         /**
 380          * Prepare the item array for an activity
 381          *
 382          * @param array  $activity Activity array
 383          * @param string $verb     Activity verb
 384          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 385          * @throws \ImagickException
 386          */
 387         public static function createActivity($activity, $verb)
 388         {
 389                 $item = self::createItem($activity);
 390                 $item['verb'] = $verb;
 391                 $item['thr-parent'] = $activity['object_id'];
 392                 $item['gravity'] = GRAVITY_ACTIVITY;
 393                 unset($item['post-type']);
 394                 $item['object-type'] = Activity\ObjectType::NOTE;
 395
 396                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 397
 398                 self::postItem($activity, $item);
 399         }
 400
 401         /**
 402          * Create an event
 403          *
 404          * @param array $activity Activity array
 405          * @param array $item
 406          *
 407          * @return int event id
 408          * @throws \Exception
 409          */
 410         public static function createEvent($activity, $item)
 411         {
 412                 $event['summary']   = HTML::toBBCode($activity['name']);
 413                 $event['desc']      = HTML::toBBCode($activity['content']);
 414                 $event['start']     = $activity['start-time'];
 415                 $event['finish']    = $activity['end-time'];
 416                 $event['nofinish']  = empty($event['finish']);
 417                 $event['location']  = $activity['location'];
 418                 $event['cid']       = $item['contact-id'];
 419                 $event['uid']       = $item['uid'];
 420                 $event['uri']       = $item['uri'];
 421                 $event['edited']    = $item['edited'];
 422                 $event['private']   = $item['private'];
 423                 $event['guid']      = $item['guid'];
 424                 $event['plink']     = $item['plink'];
 425                 $event['network']   = $item['network'];
 426                 $event['protocol']  = $item['protocol'];
 427                 $event['direction'] = $item['direction'];
 428                 $event['source']    = $item['source'];
 429
 430                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 431                 if (DBA::isResult($ev)) {
 432                         $event['id'] = $ev['id'];
 433                 }
 434
 435                 $event_id = Event::store($event);
 436
 437                 Logger::info('Event was stored', ['id' => $event_id]);
 438
 439                 return $event_id;
 440         }
 441
 442         /**
 443          * Process the content
 444          *
 445          * @param array $activity Activity array
 446          * @param array $item
 447          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 448          * @throws \Exception
 449          */
 450         private static function processContent($activity, $item)
 451         {
 452                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 453                         $item['title'] = Markdown::toBBCode($activity['name']);
 454                         $content = Markdown::toBBCode($activity['content']);
 455                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 456                         $item['title'] = $activity['name'];
 457                         $content = $activity['content'];
 458                 } else {
 459                         // By default assume "text/html"
 460                         $item['title'] = HTML::toBBCode($activity['name']);
 461                         $content = HTML::toBBCode($activity['content']);
 462                 }
 463
 464                 if (!empty($activity['languages'])) {
 465                         $item['language'] = self::processLanguages($activity['languages']);
 466                 }
 467
 468                 if (!empty($activity['emojis'])) {
 469                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 470                 }
 471
 472                 $content = self::addMentionLinks($content, $activity['tags']);
 473
 474                 if (!empty($activity['source'])) {
 475                         $item['body'] = $activity['source'];
 476                         $item['raw-body'] = $content;
 477                         $item['body'] = Item::improveSharedDataInBody($item);
 478                 } else {
 479                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 480                                 $item_private = !in_array(0, $activity['item_receiver']);
 481                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 482                                 if (!DBA::isResult($parent)) {
 483                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 484                                         return false;
 485                                 }
 486                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 487                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 488                                         return false;
 489                                 }
 490
 491                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 492                         }
 493                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 494                         $item['raw-body'] = $item['body'] = $content;
 495                 }
 496
 497                 self::storeFromBody($item);
 498                 self::storeTags($item['uri-id'], $activity['tags']);
 499
 500                 $item['location'] = $activity['location'];
 501
 502                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 503                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 504                 }
 505
 506                 $item['app'] = $activity['generator'];
 507
 508                 return $item;
 509         }
 510
 511         /**
 512          * Store hashtags and mentions
 513          *
 514          * @param array $item
 515          */
 516         private static function storeFromBody(array $item)
 517         {
 518                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 519                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 520
 521                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 522         }
 523
 524         /**
 525          * Generate a GUID out of an URL
 526          *
 527          * @param string $url message URL
 528          * @return string with GUID
 529          */
 530         private static function getGUIDByURL(string $url)
 531         {
 532                 $parsed = parse_url($url);
 533
 534                 $host_hash = hash('crc32', $parsed['host']);
 535
 536                 unset($parsed["scheme"]);
 537                 unset($parsed["host"]);
 538
 539                 $path = implode("/", $parsed);
 540
 541                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 542         }
 543
 544         /**
 545          * Creates an item post
 546          *
 547          * @param array $activity Activity data
 548          * @param array $item     item array
 549          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 550          * @throws \ImagickException
 551          */
 552         public static function postItem(array $activity, array $item)
 553         {
 554                 if (empty($item)) {
 555                         return;
 556                 }
 557
 558                 $stored = false;
 559                 ksort($activity['receiver']);
 560
 561                 foreach ($activity['receiver'] as $receiver) {
 562                         if ($receiver == -1) {
 563                                 continue;
 564                         }
 565
 566                         $item['uid'] = $receiver;
 567
 568                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 569                         switch($type) {
 570                                 case Receiver::TARGET_TO:
 571                                         $item['post-reason'] = Item::PR_TO;
 572                                         break;
 573                                 case Receiver::TARGET_CC:
 574                                         $item['post-reason'] = Item::PR_CC;
 575                                         break;
 576                                 case Receiver::TARGET_BTO:
 577                                         $item['post-reason'] = Item::PR_BTO;
 578                                         break;
 579                                 case Receiver::TARGET_BCC:
 580                                         $item['post-reason'] = Item::PR_BCC;
 581                                         break;
 582                                 case Receiver::TARGET_FOLLOWER:
 583                                         $item['post-reason'] = Item::PR_FOLLOWER;
 584                                         break;
 585                                 case Receiver::TARGET_ANSWER:
 586                                         $item['post-reason'] = Item::PR_COMMENT;
 587                                         break;
 588                                 case Receiver::TARGET_GLOBAL:
 589                                         $item['post-reason'] = Item::PR_GLOBAL;
 590                                         break;
 591                                 default:
 592                                         $item['post-reason'] = Item::PR_NONE;
 593                         }
 594
 595                         if (!empty($activity['from-relay'])) {
 596                                 $item['post-reason'] = Item::PR_RELAY;
 597                         } elseif (!empty($activity['thread-completion'])) {
 598                                 $item['post-reason'] = Item::PR_FETCHED;
 599                         }
 600
 601                         if ($item['isForum'] ?? false) {
 602                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 603                         } else {
 604                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 605                         }
 606
 607                         if (($receiver != 0) && empty($item['contact-id'])) {
 608                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 609                         }
 610
 611                         if (!empty($activity['directmessage'])) {
 612                                 self::postMail($activity, $item);
 613                                 continue;
 614                         }
 615
 616                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) &&
 617                                 ($item['post-reason'] == Item::PR_BCC) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 618                                 Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 619                                 continue;
 620                         }
 621
 622                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 623                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 624
 625                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 626                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 627                                 }
 628
 629                                 if ($skip) {
 630                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 631                                         continue;
 632                                 }
 633
 634                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 635                         }
 636
 637                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 638                                 $event_id = self::createEvent($activity, $item);
 639
 640                                 $item = Event::getItemArrayForImportedId($event_id, $item);
 641                         }
 642
 643                         $item_id = Item::insert($item);
 644                         if ($item_id) {
 645                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 646                         } else {
 647                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 648                         }
 649
 650                         if ($item['uid'] == 0) {
 651                                 $stored = $item_id;
 652                         }
 653                 }
 654
 655                 // Store send a follow request for every reshare - but only when the item had been stored
 656                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 657                         $author = APContact::getByURL($item['owner-link'], false);
 658                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 659                         if ($author['type'] != 'Group') {
 660                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 661                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 662                         }
 663                 }
 664         }
 665
 666         /**
 667          * Store tags and mentions into the tag table
 668          *
 669          * @param integer $uriid
 670          * @param array $tags
 671          */
 672         private static function storeTags(int $uriid, array $tags = null)
 673         {
 674                 foreach ($tags as $tag) {
 675                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 676                                 continue;
 677                         }
 678
 679                         $hash = substr($tag['name'], 0, 1);
 680
 681                         if ($tag['type'] == 'Mention') {
 682                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 683                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 684                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 685                                         $tag['name'] = substr($tag['name'], 1);
 686                                 }
 687                                 $type = Tag::IMPLICIT_MENTION;
 688
 689                                 if (!empty($tag['href'])) {
 690                                         $apcontact = APContact::getByURL($tag['href']);
 691                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 692                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 693                                         }
 694                                 }
 695                         } elseif ($tag['type'] == 'Hashtag') {
 696                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 697                                         $tag['name'] = substr($tag['name'], 1);
 698                                 }
 699                                 $type = Tag::HASHTAG;
 700                         }
 701
 702                         if (empty($tag['name'])) {
 703                                 continue;
 704                         }
 705
 706                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 707                 }
 708         }
 709
 710         /**
 711          * Creates an mail post
 712          *
 713          * @param array $activity Activity data
 714          * @param array $item     item array
 715          * @return int|bool New mail table row id or false on error
 716          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 717          */
 718         private static function postMail($activity, $item)
 719         {
 720                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 721                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 722                         return false;
 723                 }
 724
 725                 Logger::info('Direct Message', $item);
 726
 727                 $msg = [];
 728                 $msg['uid'] = $item['uid'];
 729
 730                 $msg['contact-id'] = $item['contact-id'];
 731
 732                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 733                 $msg['from-name'] = $contact['name'];
 734                 $msg['from-url'] = $contact['url'];
 735                 $msg['from-photo'] = $contact['photo'];
 736
 737                 $msg['uri'] = $item['uri'];
 738                 $msg['created'] = $item['created'];
 739
 740                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 741                 if (DBA::isResult($parent)) {
 742                         $msg['parent-uri'] = $parent['parent-uri'];
 743                         $msg['title'] = $parent['title'];
 744                 } else {
 745                         $msg['parent-uri'] = $item['thr-parent'];
 746
 747                         if (!empty($item['title'])) {
 748                                 $msg['title'] = $item['title'];
 749                         } elseif (!empty($item['content-warning'])) {
 750                                 $msg['title'] = $item['content-warning'];
 751                         } else {
 752                                 // Trying to generate a title out of the body
 753                                 $title = $item['body'];
 754
 755                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 756                                         $title = $matches[3];
 757                                 }
 758
 759                                 $title = trim(BBCode::toPlaintext($title));
 760
 761                                 if (strlen($title) > 20) {
 762                                         $title = substr($title, 0, 20) . '...';
 763                                 }
 764
 765                                 $msg['title'] = $title;
 766                         }
 767                 }
 768                 $msg['body'] = $item['body'];
 769
 770                 return Mail::insert($msg);
 771         }
 772
 773         /**
 774          * Fetches missing posts
 775          *
 776          * @param string $url         message URL
 777          * @param array  $child       activity array with the child of this message
 778          * @param string $relay_actor Relay actor
 779          * @return string fetched message URL
 780          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 781          */
 782         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '')
 783         {
 784                 if (!empty($child['receiver'])) {
 785                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 786                 } else {
 787                         $uid = 0;
 788                 }
 789
 790                 $object = ActivityPub::fetchContent($url, $uid);
 791                 if (empty($object)) {
 792                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url]);
 793                         return '';
 794                 }
 795
 796                 if (empty($object['id'])) {
 797                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
 798                         return '';
 799                 }
 800
 801                 if (!empty($object['actor'])) {
 802                         $object_actor = $object['actor'];
 803                 } elseif (!empty($object['attributedTo'])) {
 804                         $object_actor = $object['attributedTo'];
 805                         if (is_array($object_actor)) {
 806                                 $compacted = JsonLD::compact($object);
 807                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
 808                         }
 809                 } else {
 810                         // Shouldn't happen
 811                         $object_actor = '';
 812                 }
 813
 814                 $signer = [$object_actor];
 815
 816                 if (!empty($child['author'])) {
 817                         $actor = $child['author'];
 818                         $signer[] = $actor;
 819                 } else {
 820                         $actor = $object_actor;
 821                 }
 822
 823                 if (!empty($object['published'])) {
 824                         $published = $object['published'];
 825                 } elseif (!empty($child['published'])) {
 826                         $published = $child['published'];
 827                 } else {
 828                         $published = DateTimeFormat::utcNow();
 829                 }
 830
 831                 $activity = [];
 832                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
 833                 unset($object['@context']);
 834                 $activity['id'] = $object['id'];
 835                 $activity['to'] = $object['to'] ?? [];
 836                 $activity['cc'] = $object['cc'] ?? [];
 837                 $activity['actor'] = $actor;
 838                 $activity['object'] = $object;
 839                 $activity['published'] = $published;
 840                 $activity['type'] = 'Create';
 841
 842                 $ldactivity = JsonLD::compact($activity);
 843
 844                 if (!empty($relay_actor)) {
 845                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
 846                 } elseif (!empty($child['thread-completion'])) {
 847                         $ldactivity['thread-completion'] = $child['thread-completion'];
 848                 } else {
 849                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
 850                 }
 851
 852                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
 853                         return '';
 854                 }
 855
 856                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
 857
 858                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 859
 860                 return $activity['id'];
 861         }
 862
 863         /**
 864          * Test if incoming relay messages should be accepted
 865          *
 866          * @param array $activity activity array
 867          * @param string $id      object ID
 868          * @return boolean true if message is accepted
 869          */
 870         private static function acceptIncomingMessage(array $activity, string $id)
 871         {
 872                 if (empty($activity['as:object'])) {
 873                         Logger::info('No object field in activity - accepted', ['id' => $id]);
 874                         return true;
 875                 }
 876
 877                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
 878                 $uriid = ItemURI::getIdByURI($replyto);
 879                 if (Post::exists(['uri-id' => $uriid])) {
 880                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
 881                         return true;
 882                 }
 883
 884                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
 885                 $authorid = Contact::getIdForURL($attributed_to);
 886
 887                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value'));
 888
 889                 $messageTags = [];
 890                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
 891                 if (!empty($tags)) {
 892                         foreach ($tags as $tag) {
 893                                 if ($tag['type'] != 'Hashtag') {
 894                                         continue;
 895                                 }
 896                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
 897                         }
 898                 }
 899
 900                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
 901         }
 902
 903         /**
 904          * perform a "follow" request
 905          *
 906          * @param array $activity
 907          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 908          * @throws \ImagickException
 909          */
 910         public static function followUser($activity)
 911         {
 912                 $uid = User::getIdForURL($activity['object_id']);
 913                 if (empty($uid)) {
 914                         return;
 915                 }
 916
 917                 $owner = User::getOwnerDataById($uid);
 918                 if (empty($owner)) {
 919                         return;
 920                 }
 921
 922                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 923                 if (!empty($cid)) {
 924                         self::switchContact($cid);
 925                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 926                 }
 927
 928                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 929                         'author-link' => $activity['actor']];
 930
 931                 // Ensure that the contact has got the right network type
 932                 self::switchContact($item['author-id']);
 933
 934                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
 935                 if ($result === true) {
 936                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
 937                 }
 938
 939                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 940                 if (empty($cid)) {
 941                         return;
 942                 }
 943
 944                 if (empty($contact)) {
 945                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 946                 }
 947
 948                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 949         }
 950
 951         /**
 952          * Update the given profile
 953          *
 954          * @param array $activity
 955          * @throws \Exception
 956          */
 957         public static function updatePerson($activity)
 958         {
 959                 if (empty($activity['object_id'])) {
 960                         return;
 961                 }
 962
 963                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
 964                 Contact::updateFromProbeByURL($activity['object_id']);
 965         }
 966
 967         /**
 968          * Delete the given profile
 969          *
 970          * @param array $activity
 971          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 972          */
 973         public static function deletePerson($activity)
 974         {
 975                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 976                         Logger::info('Empty object id or actor.');
 977                         return;
 978                 }
 979
 980                 if ($activity['object_id'] != $activity['actor']) {
 981                         Logger::info('Object id does not match actor.');
 982                         return;
 983                 }
 984
 985                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 986                 while ($contact = DBA::fetch($contacts)) {
 987                         Contact::remove($contact['id']);
 988                 }
 989                 DBA::close($contacts);
 990
 991                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
 992         }
 993
 994         /**
 995          * Accept a follow request
 996          *
 997          * @param array $activity
 998          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 999          * @throws \ImagickException
1000          */
1001         public static function acceptFollowUser($activity)
1002         {
1003                 $uid = User::getIdForURL($activity['object_actor']);
1004                 if (empty($uid)) {
1005                         return;
1006                 }
1007
1008                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1009                 if (empty($cid)) {
1010                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1011                         return;
1012                 }
1013
1014                 self::switchContact($cid);
1015
1016                 $fields = ['pending' => false];
1017
1018                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1019                 if ($contact['rel'] == Contact::FOLLOWER) {
1020                         $fields['rel'] = Contact::FRIEND;
1021                 }
1022
1023                 $condition = ['id' => $cid];
1024                 Contact::update($fields, $condition);
1025                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1026         }
1027
1028         /**
1029          * Reject a follow request
1030          *
1031          * @param array $activity
1032          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1033          * @throws \ImagickException
1034          */
1035         public static function rejectFollowUser($activity)
1036         {
1037                 $uid = User::getIdForURL($activity['object_actor']);
1038                 if (empty($uid)) {
1039                         return;
1040                 }
1041
1042                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1043                 if (empty($cid)) {
1044                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1045                         return;
1046                 }
1047
1048                 self::switchContact($cid);
1049
1050                 $contact = Contact::getById($cid, ['rel']);
1051                 if ($contact['rel'] == Contact::SHARING) {
1052                         Contact::remove($cid);
1053                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1054                 } elseif ($contact['rel'] == Contact::FRIEND) {
1055                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1056                 } else {
1057                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1058                 }
1059         }
1060
1061         /**
1062          * Undo activity like "like" or "dislike"
1063          *
1064          * @param array $activity
1065          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1066          * @throws \ImagickException
1067          */
1068         public static function undoActivity($activity)
1069         {
1070                 if (empty($activity['object_id'])) {
1071                         return;
1072                 }
1073
1074                 if (empty($activity['object_actor'])) {
1075                         return;
1076                 }
1077
1078                 $author_id = Contact::getIdForURL($activity['object_actor']);
1079                 if (empty($author_id)) {
1080                         return;
1081                 }
1082
1083                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1084         }
1085
1086         /**
1087          * Activity to remove a follower
1088          *
1089          * @param array $activity
1090          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1091          * @throws \ImagickException
1092          */
1093         public static function undoFollowUser($activity)
1094         {
1095                 $uid = User::getIdForURL($activity['object_object']);
1096                 if (empty($uid)) {
1097                         return;
1098                 }
1099
1100                 $owner = User::getOwnerDataById($uid);
1101                 if (empty($owner)) {
1102                         return;
1103                 }
1104
1105                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1106                 if (empty($cid)) {
1107                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1108                         return;
1109                 }
1110
1111                 self::switchContact($cid);
1112
1113                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1114                 if (!DBA::isResult($contact)) {
1115                         return;
1116                 }
1117
1118                 Contact::removeFollower($contact);
1119                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1120         }
1121
1122         /**
1123          * Switches a contact to AP if needed
1124          *
1125          * @param integer $cid Contact ID
1126          * @throws \Exception
1127          */
1128         private static function switchContact($cid)
1129         {
1130                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1131                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1132                         return;
1133                 }
1134
1135                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1136                 Contact::updateFromProbe($cid);
1137         }
1138
1139         /**
1140          * Collects implicit mentions like:
1141          * - the author of the parent item
1142          * - all the mentioned conversants in the parent item
1143          *
1144          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1145          * @return array
1146          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1147          */
1148         private static function getImplicitMentionList(array $parent)
1149         {
1150                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1151
1152                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1153
1154                 $implicit_mentions = [];
1155                 if (empty($parent_author['url'])) {
1156                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1157                 } else {
1158                         $implicit_mentions[] = $parent_author['url'];
1159                         $implicit_mentions[] = $parent_author['nurl'];
1160                         $implicit_mentions[] = $parent_author['alias'];
1161                 }
1162
1163                 if (!empty($parent['alias'])) {
1164                         $implicit_mentions[] = $parent['alias'];
1165                 }
1166
1167                 foreach ($parent_terms as $term) {
1168                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1169                         if (!empty($contact['url'])) {
1170                                 $implicit_mentions[] = $contact['url'];
1171                                 $implicit_mentions[] = $contact['nurl'];
1172                                 $implicit_mentions[] = $contact['alias'];
1173                         }
1174                 }
1175
1176                 return $implicit_mentions;
1177         }
1178
1179         /**
1180          * Strips from the body prepended implicit mentions
1181          *
1182          * @param string $body
1183          * @param array $parent
1184          * @return string
1185          */
1186         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1187         {
1188                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1189                         return $body;
1190                 }
1191
1192                 $potential_mentions = self::getImplicitMentionList($parent);
1193
1194                 $kept_mentions = [];
1195
1196                 // Extract one prepended mention at a time from the body
1197                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1198                         if (!in_array($matches[2], $potential_mentions)) {
1199                                 $kept_mentions[] = $matches[1];
1200                         }
1201
1202                         $body = $matches[3];
1203                 }
1204
1205                 // Re-appending the kept mentions to the body after extraction
1206                 $kept_mentions[] = $body;
1207
1208                 return implode('', $kept_mentions);
1209         }
1210
1211         /**
1212          * Adds links to string mentions
1213          *
1214          * @param string $body
1215          * @param array  $tags
1216          * @return string
1217          */
1218         protected static function addMentionLinks(string $body, array $tags): string
1219         {
1220                 // This prevents links to be added again to Pleroma-style mention links
1221                 $body = self::normalizeMentionLinks($body);
1222
1223                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1224                         foreach ($tags as $tag) {
1225                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1226                                         continue;
1227                                 }
1228
1229                                 $hash = substr($tag['name'], 0, 1);
1230                                 $name = substr($tag['name'], 1);
1231                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1232                                         $hash = '';
1233                                         $name = $tag['name'];
1234                                 }
1235
1236                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1237                         }
1238
1239                         return $body;
1240                 });
1241
1242                 return $body;
1243         }
1244 }