src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2021, 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          * Converts mentions from Pleroma into the Friendica format
  57          *
  58          * @param string $body
  59          *
  60          * @return string converted body
  61          */
  62         private static function convertMentions($body)
  63         {
  64                 $URLSearchString = "^\[\]";
  65                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
  66
  67                 return $body;
  68         }
  69
  70         /**
  71          * Convert the language array into a language JSON
  72          *
  73          * @param array $languages
  74          * @return string language JSON
  75          */
  76         private static function processLanguages(array $languages)
  77         {
  78                 $codes = array_keys($languages);
  79                 $lang = [];
  80                 foreach ($codes as $code) {
  81                         $lang[$code] = 1;
  82                 }
  83
  84                 if (empty($lang)) {
  85                         return '';
  86                 }
  87
  88                 return json_encode($lang);
  89         }
  90         /**
  91          * Replaces emojis in the body
  92          *
  93          * @param array $emojis
  94          * @param string $body
  95          *
  96          * @return string with replaced emojis
  97          */
  98         private static function replaceEmojis($body, array $emojis)
  99         {
 100                 $body = strtr($body,
 101                         array_combine(
 102                                 array_column($emojis, 'name'),
 103                                 array_map(function ($emoji) {
 104                                         return '[class=emoji mastodon][img=' . $emoji['href'] . ']' . $emoji['name'] . '[/img][/class]';
 105                                 }, $emojis)
 106                         )
 107                 );
 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                 if (empty($activity['reply-to-id'])) {
 196                         $activity['reply-to-id'] = $activity['id'];
 197                 }
 198
 199                 $item = [];
 200                 $item['verb'] = Activity::POST;
 201                 $item['thr-parent'] = $activity['reply-to-id'];
 202
 203                 if ($activity['reply-to-id'] == $activity['id']) {
 204                         $item['gravity'] = GRAVITY_PARENT;
 205                         $item['object-type'] = Activity\ObjectType::NOTE;
 206                 } else {
 207                         $item['gravity'] = GRAVITY_COMMENT;
 208                         $item['object-type'] = Activity\ObjectType::COMMENT;
 209                 }
 210
 211                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 212                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 213                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 214                 }
 215
 216                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 217
 218                 /// @todo What to do with $activity['context']?
 219                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 220                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 221                         return [];
 222                 }
 223
 224                 $item['network'] = Protocol::ACTIVITYPUB;
 225                 $item['author-link'] = $activity['author'];
 226                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 227                 $item['owner-link'] = $activity['actor'];
 228                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 229
 230                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 231                         $item['private'] = Item::UNLISTED;
 232                 } elseif (in_array(0, $activity['receiver'])) {
 233                         $item['private'] = Item::PUBLIC;
 234                 } else {
 235                         $item['private'] = Item::PRIVATE;
 236                 }
 237
 238                 if (!empty($activity['raw'])) {
 239                         $item['source'] = $activity['raw'];
 240                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 241                         $item['conversation-href'] = $activity['context'] ?? '';
 242                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 243
 244                         if (isset($activity['push'])) {
 245                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 246                         }
 247                 }
 248
 249                 if (!empty($activity['from-relay'])) {
 250                         $item['direction'] = Conversation::RELAY;
 251                 }
 252
 253                 if ($activity['object_type'] == 'as:Article') {
 254                         $item['post-type'] = Item::PT_ARTICLE;
 255                 } elseif ($activity['object_type'] == 'as:Audio') {
 256                         $item['post-type'] = Item::PT_AUDIO;
 257                 } elseif ($activity['object_type'] == 'as:Document') {
 258                         $item['post-type'] = Item::PT_DOCUMENT;
 259                 } elseif ($activity['object_type'] == 'as:Event') {
 260                         $item['post-type'] = Item::PT_EVENT;
 261                 } elseif ($activity['object_type'] == 'as:Image') {
 262                         $item['post-type'] = Item::PT_IMAGE;
 263                 } elseif ($activity['object_type'] == 'as:Page') {
 264                         $item['post-type'] = Item::PT_PAGE;
 265                 } elseif ($activity['object_type'] == 'as:Video') {
 266                         $item['post-type'] = Item::PT_VIDEO;
 267                 } else {
 268                         $item['post-type'] = Item::PT_NOTE;
 269                 }
 270
 271                 $item['isForum'] = false;
 272
 273                 if (!empty($activity['thread-completion'])) {
 274                         if ($activity['thread-completion'] != $item['owner-id']) {
 275                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 276                                 $item['causer-link'] = $actor['url'];
 277                                 $item['causer-id'] = $activity['thread-completion'];
 278                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 279                         } else {
 280                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 281                                 $item['causer-link'] = $item['owner-link'];
 282                                 $item['causer-id'] = $item['owner-id'];
 283                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 284                         }
 285
 286                         $item['owner-link'] = $item['author-link'];
 287                         $item['owner-id'] = $item['author-id'];
 288                 } else {
 289                         $actor = APContact::getByURL($item['owner-link'], false);
 290                         $item['isForum'] = ($actor['type'] == 'Group');
 291                 }
 292
 293                 $item['uri'] = $activity['id'];
 294
 295                 $item['created'] = DateTimeFormat::utc($activity['published']);
 296                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 297                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 298                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 299
 300                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 301                 if (empty($item['uri-id'])) {
 302                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 303                         return [];
 304                 }
 305
 306                 $item = self::processContent($activity, $item);
 307                 if (empty($item)) {
 308                         Logger::info('Message was not processed');
 309                         return [];
 310                 }
 311
 312                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 313
 314                 self::storeAttachments($activity, $item);
 315
 316                 // We received the post via AP, so we set the protocol of the server to AP
 317                 $contact = Contact::getById($item['author-id'], ['gsid']);
 318                 if (!empty($contact['gsid'])) {
 319                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 320                 }
 321
 322                 if ($item['author-id'] != $item['owner-id']) {
 323                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 324                         if (!empty($contact['gsid'])) {
 325                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 326                         }
 327                 }
 328
 329                 return $item;
 330         }
 331
 332         /**
 333          * Delete items
 334          *
 335          * @param array $activity
 336          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 337          * @throws \ImagickException
 338          */
 339         public static function deleteItem($activity)
 340         {
 341                 $owner = Contact::getIdForURL($activity['actor']);
 342
 343                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 344                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 345         }
 346
 347         /**
 348          * Prepare the item array for an activity
 349          *
 350          * @param array $activity Activity array
 351          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 352          * @throws \ImagickException
 353          */
 354         public static function addTag($activity)
 355         {
 356                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 357                         return;
 358                 }
 359
 360                 foreach ($activity['receiver'] as $receiver) {
 361                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 362                         if (!DBA::isResult($item)) {
 363                                 // We don't fetch missing content for this purpose
 364                                 continue;
 365                         }
 366
 367                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 368                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 369                                 continue;
 370                         }
 371
 372                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 373                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 374                 }
 375         }
 376
 377         /**
 378          * Prepare the item array for an activity
 379          *
 380          * @param array  $activity Activity array
 381          * @param string $verb     Activity verb
 382          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 383          * @throws \ImagickException
 384          */
 385         public static function createActivity($activity, $verb)
 386         {
 387                 $item = self::createItem($activity);
 388                 $item['verb'] = $verb;
 389                 $item['thr-parent'] = $activity['object_id'];
 390                 $item['gravity'] = GRAVITY_ACTIVITY;
 391                 unset($item['post-type']);
 392                 $item['object-type'] = Activity\ObjectType::NOTE;
 393
 394                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 395
 396                 self::postItem($activity, $item);
 397         }
 398
 399         /**
 400          * Create an event
 401          *
 402          * @param array $activity Activity array
 403          * @param array $item
 404          * @throws \Exception
 405          */
 406         public static function createEvent($activity, $item)
 407         {
 408                 $event['summary']   = HTML::toBBCode($activity['name']);
 409                 $event['desc']      = HTML::toBBCode($activity['content']);
 410                 $event['start']     = $activity['start-time'];
 411                 $event['finish']    = $activity['end-time'];
 412                 $event['nofinish']  = empty($event['finish']);
 413                 $event['location']  = $activity['location'];
 414                 $event['adjust']    = $activity['adjust'] ?? true;
 415                 $event['cid']       = $item['contact-id'];
 416                 $event['uid']       = $item['uid'];
 417                 $event['uri']       = $item['uri'];
 418                 $event['edited']    = $item['edited'];
 419                 $event['private']   = $item['private'];
 420                 $event['guid']      = $item['guid'];
 421                 $event['plink']     = $item['plink'];
 422                 $event['network']   = $item['network'];
 423                 $event['protocol']  = $item['protocol'];
 424                 $event['direction'] = $item['direction'];
 425                 $event['source']    = $item['source'];
 426
 427                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 428                 $ev = DBA::selectFirst('event', ['id'], $condition);
 429                 if (DBA::isResult($ev)) {
 430                         $event['id'] = $ev['id'];
 431                 }
 432
 433                 $event_id = Event::store($event);
 434                 Logger::info('Event was stored', ['id' => $event_id]);
 435         }
 436
 437         /**
 438          * Process the content
 439          *
 440          * @param array $activity Activity array
 441          * @param array $item
 442          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 443          * @throws \Exception
 444          */
 445         private static function processContent($activity, $item)
 446         {
 447                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 448                         $item['title'] = Markdown::toBBCode($activity['name']);
 449                         $content = Markdown::toBBCode($activity['content']);
 450                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 451                         $item['title'] = $activity['name'];
 452                         $content = $activity['content'];
 453                 } else {
 454                         // By default assume "text/html"
 455                         $item['title'] = HTML::toBBCode($activity['name']);
 456                         $content = HTML::toBBCode($activity['content']);
 457                 }
 458
 459                 if (!empty($activity['languages'])) {
 460                         $item['language'] = self::processLanguages($activity['languages']);
 461                 }
 462
 463                 if (!empty($activity['emojis'])) {
 464                         $content = self::replaceEmojis($content, $activity['emojis']);
 465                 }
 466
 467                 $content = self::convertMentions($content);
 468
 469                 if (!empty($activity['source'])) {
 470                         $item['body'] = $activity['source'];
 471                         $item['raw-body'] = $content;
 472                         $item['body'] = Item::improveSharedDataInBody($item);
 473                 } else {
 474                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 475                                 $item_private = !in_array(0, $activity['item_receiver']);
 476                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 477                                 if (!DBA::isResult($parent)) {
 478                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 479                                         return false;
 480                                 }
 481                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 482                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 483                                         return false;
 484                                 }
 485
 486                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 487                         }
 488                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 489                         $item['raw-body'] = $item['body'] = $content;
 490                 }
 491
 492                 self::storeFromBody($item);
 493                 self::storeTags($item['uri-id'], $activity['tags']);
 494
 495                 $item['location'] = $activity['location'];
 496
 497                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 498                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 499                 }
 500
 501                 $item['app'] = $activity['generator'];
 502
 503                 return $item;
 504         }
 505
 506         /**
 507          * Store hashtags and mentions
 508          *
 509          * @param array $item
 510          */
 511         private static function storeFromBody(array $item)
 512         {
 513                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 514                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 515
 516                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 517         }
 518
 519         /**
 520          * Generate a GUID out of an URL
 521          *
 522          * @param string $url message URL
 523          * @return string with GUID
 524          */
 525         private static function getGUIDByURL(string $url)
 526         {
 527                 $parsed = parse_url($url);
 528
 529                 $host_hash = hash('crc32', $parsed['host']);
 530
 531                 unset($parsed["scheme"]);
 532                 unset($parsed["host"]);
 533
 534                 $path = implode("/", $parsed);
 535
 536                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 537         }
 538
 539         /**
 540          * Creates an item post
 541          *
 542          * @param array $activity Activity data
 543          * @param array $item     item array
 544          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 545          * @throws \ImagickException
 546          */
 547         public static function postItem(array $activity, array $item)
 548         {
 549                 if (empty($item)) {
 550                         return;
 551                 }
 552
 553                 $stored = false;
 554                 ksort($activity['receiver']);
 555
 556                 foreach ($activity['receiver'] as $receiver) {
 557                         if ($receiver == -1) {
 558                                 continue;
 559                         }
 560
 561                         $item['uid'] = $receiver;
 562
 563                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 564                         switch($type) {
 565                                 case Receiver::TARGET_TO:
 566                                         $item['post-reason'] = Item::PR_TO;
 567                                         break;
 568                                 case Receiver::TARGET_CC:
 569                                         $item['post-reason'] = Item::PR_CC;
 570                                         break;
 571                                 case Receiver::TARGET_BTO:
 572                                         $item['post-reason'] = Item::PR_BTO;
 573                                         break;
 574                                 case Receiver::TARGET_BCC:
 575                                         $item['post-reason'] = Item::PR_BCC;
 576                                         break;
 577                                 case Receiver::TARGET_FOLLOWER:
 578                                         $item['post-reason'] = Item::PR_FOLLOWER;
 579                                         break;
 580                                 case Receiver::TARGET_ANSWER:
 581                                         $item['post-reason'] = Item::PR_COMMENT;
 582                                         break;
 583                                 case Receiver::TARGET_GLOBAL:
 584                                         $item['post-reason'] = Item::PR_GLOBAL;
 585                                         break;
 586                                 default:
 587                                         $item['post-reason'] = Item::PR_NONE;
 588                         }
 589
 590                         if (!empty($activity['from-relay'])) {
 591                                 $item['post-reason'] = Item::PR_RELAY;
 592                         } elseif (!empty($activity['thread-completion'])) {
 593                                 $item['post-reason'] = Item::PR_FETCHED;
 594                         }
 595
 596                         if ($item['isForum'] ?? false) {
 597                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 598                         } else {
 599                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 600                         }
 601
 602                         if (($receiver != 0) && empty($item['contact-id'])) {
 603                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 604                         }
 605
 606                         if (!empty($activity['directmessage'])) {
 607                                 self::postMail($activity, $item);
 608                                 continue;
 609                         }
 610
 611                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) &&
 612                                 ($item['post-reason'] == Item::PR_BCC) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 613                                 Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 614                                 continue;
 615                         }
 616
 617                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 618                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 619
 620                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 621                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 622                                 }
 623
 624                                 if ($skip) {
 625                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 626                                         continue;
 627                                 }
 628
 629                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 630                         }
 631
 632                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 633                                 self::createEvent($activity, $item);
 634                         }
 635
 636                         $item_id = Item::insert($item);
 637                         if ($item_id) {
 638                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 639                         } else {
 640                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 641                         }
 642
 643                         if ($item['uid'] == 0) {
 644                                 $stored = $item_id;
 645                         }
 646                 }
 647
 648                 // Store send a follow request for every reshare - but only when the item had been stored
 649                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 650                         $author = APContact::getByURL($item['owner-link'], false);
 651                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 652                         if ($author['type'] != 'Group') {
 653                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 654                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 655                         }
 656                 }
 657         }
 658
 659         /**
 660          * Store tags and mentions into the tag table
 661          *
 662          * @param integer $uriid
 663          * @param array $tags
 664          */
 665         private static function storeTags(int $uriid, array $tags = null)
 666         {
 667                 foreach ($tags as $tag) {
 668                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 669                                 continue;
 670                         }
 671
 672                         $hash = substr($tag['name'], 0, 1);
 673
 674                         if ($tag['type'] == 'Mention') {
 675                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 676                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 677                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 678                                         $tag['name'] = substr($tag['name'], 1);
 679                                 }
 680                                 $type = Tag::IMPLICIT_MENTION;
 681
 682                                 if (!empty($tag['href'])) {
 683                                         $apcontact = APContact::getByURL($tag['href']);
 684                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 685                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 686                                         }
 687                                 }
 688                         } elseif ($tag['type'] == 'Hashtag') {
 689                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 690                                         $tag['name'] = substr($tag['name'], 1);
 691                                 }
 692                                 $type = Tag::HASHTAG;
 693                         }
 694
 695                         if (empty($tag['name'])) {
 696                                 continue;
 697                         }
 698
 699                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 700                 }
 701         }
 702
 703         /**
 704          * Creates an mail post
 705          *
 706          * @param array $activity Activity data
 707          * @param array $item     item array
 708          * @return int|bool New mail table row id or false on error
 709          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 710          */
 711         private static function postMail($activity, $item)
 712         {
 713                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 714                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 715                         return false;
 716                 }
 717
 718                 Logger::info('Direct Message', $item);
 719
 720                 $msg = [];
 721                 $msg['uid'] = $item['uid'];
 722
 723                 $msg['contact-id'] = $item['contact-id'];
 724
 725                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 726                 $msg['from-name'] = $contact['name'];
 727                 $msg['from-url'] = $contact['url'];
 728                 $msg['from-photo'] = $contact['photo'];
 729
 730                 $msg['uri'] = $item['uri'];
 731                 $msg['created'] = $item['created'];
 732
 733                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 734                 if (DBA::isResult($parent)) {
 735                         $msg['parent-uri'] = $parent['parent-uri'];
 736                         $msg['title'] = $parent['title'];
 737                 } else {
 738                         $msg['parent-uri'] = $item['thr-parent'];
 739
 740                         if (!empty($item['title'])) {
 741                                 $msg['title'] = $item['title'];
 742                         } elseif (!empty($item['content-warning'])) {
 743                                 $msg['title'] = $item['content-warning'];
 744                         } else {
 745                                 // Trying to generate a title out of the body
 746                                 $title = $item['body'];
 747
 748                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 749                                         $title = $matches[3];
 750                                 }
 751
 752                                 $title = trim(BBCode::toPlaintext($title));
 753
 754                                 if (strlen($title) > 20) {
 755                                         $title = substr($title, 0, 20) . '...';
 756                                 }
 757
 758                                 $msg['title'] = $title;
 759                         }
 760                 }
 761                 $msg['body'] = $item['body'];
 762
 763                 return Mail::insert($msg);
 764         }
 765
 766         /**
 767          * Fetches missing posts
 768          *
 769          * @param string $url         message URL
 770          * @param array  $child       activity array with the child of this message
 771          * @param string $relay_actor Relay actor
 772          * @return string fetched message URL
 773          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 774          */
 775         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '')
 776         {
 777                 if (!empty($child['receiver'])) {
 778                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 779                 } else {
 780                         $uid = 0;
 781                 }
 782
 783                 $object = ActivityPub::fetchContent($url, $uid);
 784                 if (empty($object)) {
 785                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url]);
 786                         return '';
 787                 }
 788
 789                 if (empty($object['id'])) {
 790                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
 791                         return '';
 792                 }
 793
 794                 if (!empty($object['actor'])) {
 795                         $object_actor = $object['actor'];
 796                 } elseif (!empty($object['attributedTo'])) {
 797                         $object_actor = $object['attributedTo'];
 798                         if (is_array($object_actor)) {
 799                                 $compacted = JsonLD::compact($object);
 800                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
 801                         }
 802                 } else {
 803                         // Shouldn't happen
 804                         $object_actor = '';
 805                 }
 806
 807                 $signer = [$object_actor];
 808
 809                 if (!empty($child['author'])) {
 810                         $actor = $child['author'];
 811                         $signer[] = $actor;
 812                 } else {
 813                         $actor = $object_actor;
 814                 }
 815
 816                 if (!empty($object['published'])) {
 817                         $published = $object['published'];
 818                 } elseif (!empty($child['published'])) {
 819                         $published = $child['published'];
 820                 } else {
 821                         $published = DateTimeFormat::utcNow();
 822                 }
 823
 824                 $activity = [];
 825                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
 826                 unset($object['@context']);
 827                 $activity['id'] = $object['id'];
 828                 $activity['to'] = $object['to'] ?? [];
 829                 $activity['cc'] = $object['cc'] ?? [];
 830                 $activity['actor'] = $actor;
 831                 $activity['object'] = $object;
 832                 $activity['published'] = $published;
 833                 $activity['type'] = 'Create';
 834
 835                 $ldactivity = JsonLD::compact($activity);
 836
 837                 if (!empty($relay_actor)) {
 838                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
 839                 } elseif (!empty($child['thread-completion'])) {
 840                         $ldactivity['thread-completion'] = $child['thread-completion'];
 841                 } else {
 842                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
 843                 }
 844
 845                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
 846                         return '';
 847                 }
 848
 849                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
 850
 851                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 852
 853                 return $activity['id'];
 854         }
 855
 856         /**
 857          * Test if incoming relay messages should be accepted
 858          *
 859          * @param array $activity activity array
 860          * @param string $id      object ID
 861          * @return boolean true if message is accepted
 862          */
 863         private static function acceptIncomingMessage(array $activity, string $id)
 864         {
 865                 if (empty($activity['as:object'])) {
 866                         Logger::info('No object field in activity - accepted', ['id' => $id]);
 867                         return true;
 868                 }
 869
 870                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
 871                 $uriid = ItemURI::getIdByURI($replyto);
 872                 if (Post::exists(['uri-id' => $uriid])) {
 873                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
 874                         return true;
 875                 }
 876
 877                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
 878                 $authorid = Contact::getIdForURL($attributed_to);
 879
 880                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value'));
 881
 882                 $messageTags = [];
 883                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
 884                 if (!empty($tags)) {
 885                         foreach ($tags as $tag) {
 886                                 if ($tag['type'] != 'Hashtag') {
 887                                         continue;
 888                                 }
 889                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
 890                         }
 891                 }
 892
 893                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
 894         }
 895
 896         /**
 897          * perform a "follow" request
 898          *
 899          * @param array $activity
 900          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 901          * @throws \ImagickException
 902          */
 903         public static function followUser($activity)
 904         {
 905                 $uid = User::getIdForURL($activity['object_id']);
 906                 if (empty($uid)) {
 907                         return;
 908                 }
 909
 910                 $owner = User::getOwnerDataById($uid);
 911                 if (empty($owner)) {
 912                         return;
 913                 }
 914
 915                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 916                 if (!empty($cid)) {
 917                         self::switchContact($cid);
 918                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 919                 }
 920
 921                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 922                         'author-link' => $activity['actor']];
 923
 924                 // Ensure that the contact has got the right network type
 925                 self::switchContact($item['author-id']);
 926
 927                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
 928                 if ($result === true) {
 929                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
 930                 }
 931
 932                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 933                 if (empty($cid)) {
 934                         return;
 935                 }
 936
 937                 if (empty($contact)) {
 938                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 939                 }
 940
 941                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 942         }
 943
 944         /**
 945          * Update the given profile
 946          *
 947          * @param array $activity
 948          * @throws \Exception
 949          */
 950         public static function updatePerson($activity)
 951         {
 952                 if (empty($activity['object_id'])) {
 953                         return;
 954                 }
 955
 956                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
 957                 Contact::updateFromProbeByURL($activity['object_id']);
 958         }
 959
 960         /**
 961          * Delete the given profile
 962          *
 963          * @param array $activity
 964          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 965          */
 966         public static function deletePerson($activity)
 967         {
 968                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 969                         Logger::info('Empty object id or actor.');
 970                         return;
 971                 }
 972
 973                 if ($activity['object_id'] != $activity['actor']) {
 974                         Logger::info('Object id does not match actor.');
 975                         return;
 976                 }
 977
 978                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 979                 while ($contact = DBA::fetch($contacts)) {
 980                         Contact::remove($contact['id']);
 981                 }
 982                 DBA::close($contacts);
 983
 984                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
 985         }
 986
 987         /**
 988          * Accept a follow request
 989          *
 990          * @param array $activity
 991          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 992          * @throws \ImagickException
 993          */
 994         public static function acceptFollowUser($activity)
 995         {
 996                 $uid = User::getIdForURL($activity['object_actor']);
 997                 if (empty($uid)) {
 998                         return;
 999                 }
1000
1001                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1002                 if (empty($cid)) {
1003                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1004                         return;
1005                 }
1006
1007                 self::switchContact($cid);
1008
1009                 $fields = ['pending' => false];
1010
1011                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1012                 if ($contact['rel'] == Contact::FOLLOWER) {
1013                         $fields['rel'] = Contact::FRIEND;
1014                 }
1015
1016                 $condition = ['id' => $cid];
1017                 DBA::update('contact', $fields, $condition);
1018                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1019         }
1020
1021         /**
1022          * Reject a follow request
1023          *
1024          * @param array $activity
1025          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1026          * @throws \ImagickException
1027          */
1028         public static function rejectFollowUser($activity)
1029         {
1030                 $uid = User::getIdForURL($activity['object_actor']);
1031                 if (empty($uid)) {
1032                         return;
1033                 }
1034
1035                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1036                 if (empty($cid)) {
1037                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1038                         return;
1039                 }
1040
1041                 self::switchContact($cid);
1042
1043                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
1044                         Contact::remove($cid);
1045                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1046                 } else {
1047                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1048                 }
1049         }
1050
1051         /**
1052          * Undo activity like "like" or "dislike"
1053          *
1054          * @param array $activity
1055          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1056          * @throws \ImagickException
1057          */
1058         public static function undoActivity($activity)
1059         {
1060                 if (empty($activity['object_id'])) {
1061                         return;
1062                 }
1063
1064                 if (empty($activity['object_actor'])) {
1065                         return;
1066                 }
1067
1068                 $author_id = Contact::getIdForURL($activity['object_actor']);
1069                 if (empty($author_id)) {
1070                         return;
1071                 }
1072
1073                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1074         }
1075
1076         /**
1077          * Activity to remove a follower
1078          *
1079          * @param array $activity
1080          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1081          * @throws \ImagickException
1082          */
1083         public static function undoFollowUser($activity)
1084         {
1085                 $uid = User::getIdForURL($activity['object_object']);
1086                 if (empty($uid)) {
1087                         return;
1088                 }
1089
1090                 $owner = User::getOwnerDataById($uid);
1091                 if (empty($owner)) {
1092                         return;
1093                 }
1094
1095                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1096                 if (empty($cid)) {
1097                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1098                         return;
1099                 }
1100
1101                 self::switchContact($cid);
1102
1103                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1104                 if (!DBA::isResult($contact)) {
1105                         return;
1106                 }
1107
1108                 Contact::removeFollower($owner, $contact);
1109                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1110         }
1111
1112         /**
1113          * Switches a contact to AP if needed
1114          *
1115          * @param integer $cid Contact ID
1116          * @throws \Exception
1117          */
1118         private static function switchContact($cid)
1119         {
1120                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1121                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1122                         return;
1123                 }
1124
1125                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1126                 Contact::updateFromProbe($cid);
1127         }
1128
1129         /**
1130          * Collects implicit mentions like:
1131          * - the author of the parent item
1132          * - all the mentioned conversants in the parent item
1133          *
1134          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1135          * @return array
1136          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1137          */
1138         private static function getImplicitMentionList(array $parent)
1139         {
1140                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1141
1142                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1143
1144                 $implicit_mentions = [];
1145                 if (empty($parent_author['url'])) {
1146                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1147                 } else {
1148                         $implicit_mentions[] = $parent_author['url'];
1149                         $implicit_mentions[] = $parent_author['nurl'];
1150                         $implicit_mentions[] = $parent_author['alias'];
1151                 }
1152
1153                 if (!empty($parent['alias'])) {
1154                         $implicit_mentions[] = $parent['alias'];
1155                 }
1156
1157                 foreach ($parent_terms as $term) {
1158                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1159                         if (!empty($contact['url'])) {
1160                                 $implicit_mentions[] = $contact['url'];
1161                                 $implicit_mentions[] = $contact['nurl'];
1162                                 $implicit_mentions[] = $contact['alias'];
1163                         }
1164                 }
1165
1166                 return $implicit_mentions;
1167         }
1168
1169         /**
1170          * Strips from the body prepended implicit mentions
1171          *
1172          * @param string $body
1173          * @param array $parent
1174          * @return string
1175          */
1176         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1177         {
1178                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1179                         return $body;
1180                 }
1181
1182                 $potential_mentions = self::getImplicitMentionList($parent);
1183
1184                 $kept_mentions = [];
1185
1186                 // Extract one prepended mention at a time from the body
1187                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1188                         if (!in_array($matches[2], $potential_mentions)) {
1189                                 $kept_mentions[] = $matches[1];
1190                         }
1191
1192                         $body = $matches[3];
1193                 }
1194
1195                 // Re-appending the kept mentions to the body after extraction
1196                 $kept_mentions[] = $body;
1197
1198                 return implode('', $kept_mentions);
1199         }
1200 }