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\Database\DBA;
  30 use Friendica\DI;
  31 use Friendica\Model\APContact;
  32 use Friendica\Model\Contact;
  33 use Friendica\Model\Conversation;
  34 use Friendica\Model\Event;
  35 use Friendica\Model\GServer;
  36 use Friendica\Model\Item;
  37 use Friendica\Model\ItemURI;
  38 use Friendica\Model\Mail;
  39 use Friendica\Model\Tag;
  40 use Friendica\Model\User;
  41 use Friendica\Model\Post;
  42 use Friendica\Protocol\Activity;
  43 use Friendica\Protocol\ActivityPub;
  44 use Friendica\Protocol\Relay;
  45 use Friendica\Util\DateTimeFormat;
  46 use Friendica\Util\JsonLD;
  47 use Friendica\Util\Strings;
  48
  49 /**
  50  * ActivityPub Processor Protocol class
  51  */
  52 class Processor
  53 {
  54         /**
  55          * Converts mentions from Pleroma into the Friendica format
  56          *
  57          * @param string $body
  58          *
  59          * @return string converted body
  60          */
  61         private static function convertMentions($body)
  62         {
  63                 $URLSearchString = "^\[\]";
  64                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
  65
  66                 return $body;
  67         }
  68
  69         /**
  70          * Convert the language array into a language JSON
  71          *
  72          * @param array $languages
  73          * @return string language JSON
  74          */
  75         private static function processLanguages(array $languages)
  76         {
  77                 $codes = array_keys($languages);
  78                 $lang = [];
  79                 foreach ($codes as $code) {
  80                         $lang[$code] = 1;
  81                 }
  82
  83                 if (empty($lang)) {
  84                         return '';
  85                 }
  86
  87                 return json_encode($lang);
  88         }
  89         /**
  90          * Replaces emojis in the body
  91          *
  92          * @param array $emojis
  93          * @param string $body
  94          *
  95          * @return string with replaced emojis
  96          */
  97         private static function replaceEmojis($body, array $emojis)
  98         {
  99                 $body = strtr($body,
 100                         array_combine(
 101                                 array_column($emojis, 'name'),
 102                                 array_map(function ($emoji) {
 103                                         return '[class=emoji mastodon][img=' . $emoji['href'] . ']' . $emoji['name'] . '[/img][/class]';
 104                                 }, $emojis)
 105                         )
 106                 );
 107
 108                 return $body;
 109         }
 110
 111         /**
 112          * Store attached media files in the post-media table
 113          *
 114          * @param int $uriid
 115          * @param array $attachment
 116          * @return void
 117          */
 118         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
 119         {
 120                 if (empty($attachment['url'])) {
 121                         return;
 122                 }
 123
 124                 $data = ['uri-id' => $uriid];
 125                 $data['type'] = Post\Media::UNKNOWN;
 126                 $data['url'] = $attachment['url'];
 127                 $data['mimetype'] = $attachment['mediaType'];
 128                 $data['height'] = $attachment['height'] ?? null;
 129                 $data['width'] = $attachment['width'] ?? null;
 130                 $data['size'] = $attachment['size'] ?? null;
 131                 $data['preview'] = $attachment['image'] ?? null;
 132                 $data['description'] = $attachment['name'] ?? null;
 133
 134                 Post\Media::insert($data);
 135         }
 136
 137         /**
 138          * Stire attachment data
 139          *
 140          * @param array   $activity
 141          * @param array   $item
 142          */
 143         private static function storeAttachments($activity, $item)
 144         {
 145                 if (empty($activity['attachments'])) {
 146                         return;
 147                 }
 148
 149                 foreach ($activity['attachments'] as $attach) {
 150                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 151                 }
 152         }
 153
 154         /**
 155          * Updates a message
 156          *
 157          * @param array $activity Activity array
 158          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 159          */
 160         public static function updateItem($activity)
 161         {
 162                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type'], ['uri' => $activity['id']]);
 163                 if (!DBA::isResult($item)) {
 164                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 165                         $item = self::createItem($activity);
 166                         self::postItem($activity, $item);
 167                         return;
 168                 }
 169
 170                 $item['changed'] = DateTimeFormat::utcNow();
 171                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 172
 173                 $item = self::processContent($activity, $item);
 174
 175                 self::storeAttachments($activity, $item);
 176
 177                 if (empty($item)) {
 178                         return;
 179                 }
 180
 181                 Item::update($item, ['uri' => $activity['id']]);
 182         }
 183
 184         /**
 185          * Prepares data for a message
 186          *
 187          * @param array $activity Activity array
 188          * @return array Internal item
 189          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 190          * @throws \ImagickException
 191          */
 192         public static function createItem($activity)
 193         {
 194                 $item = [];
 195                 $item['verb'] = Activity::POST;
 196                 $item['thr-parent'] = $activity['reply-to-id'];
 197
 198                 if ($activity['reply-to-id'] == $activity['id']) {
 199                         $item['gravity'] = GRAVITY_PARENT;
 200                         $item['object-type'] = Activity\ObjectType::NOTE;
 201                 } else {
 202                         $item['gravity'] = GRAVITY_COMMENT;
 203                         $item['object-type'] = Activity\ObjectType::COMMENT;
 204                 }
 205
 206                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 207                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 208                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 209                 }
 210
 211                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 212
 213                 /// @todo What to do with $activity['context']?
 214                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 215                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 216                         return [];
 217                 }
 218
 219                 $item['network'] = Protocol::ACTIVITYPUB;
 220                 $item['author-link'] = $activity['author'];
 221                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 222                 $item['owner-link'] = $activity['actor'];
 223                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 224
 225                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 226                         $item['private'] = Item::UNLISTED;
 227                 } elseif (in_array(0, $activity['receiver'])) {
 228                         $item['private'] = Item::PUBLIC;
 229                 } else {
 230                         $item['private'] = Item::PRIVATE;
 231                 }
 232
 233                 if (!empty($activity['raw'])) {
 234                         $item['source'] = $activity['raw'];
 235                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 236                         $item['conversation-href'] = $activity['context'] ?? '';
 237                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 238
 239                         if (isset($activity['push'])) {
 240                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 241                         }
 242                 }
 243
 244                 if (!empty($activity['from-relay'])) {
 245                         $item['direction'] = Conversation::RELAY;
 246                 }
 247
 248                 if ($activity['object_type'] == 'as:Article') {
 249                         $item['post-type'] = Item::PT_ARTICLE;
 250                 } elseif ($activity['object_type'] == 'as:Audio') {
 251                         $item['post-type'] = Item::PT_AUDIO;
 252                 } elseif ($activity['object_type'] == 'as:Document') {
 253                         $item['post-type'] = Item::PT_DOCUMENT;
 254                 } elseif ($activity['object_type'] == 'as:Event') {
 255                         $item['post-type'] = Item::PT_EVENT;
 256                 } elseif ($activity['object_type'] == 'as:Image') {
 257                         $item['post-type'] = Item::PT_IMAGE;
 258                 } elseif ($activity['object_type'] == 'as:Page') {
 259                         $item['post-type'] = Item::PT_PAGE;
 260                 } elseif ($activity['object_type'] == 'as:Video') {
 261                         $item['post-type'] = Item::PT_VIDEO;
 262                 } else {
 263                         $item['post-type'] = Item::PT_NOTE;
 264                 }
 265
 266                 $item['isForum'] = false;
 267
 268                 if (!empty($activity['thread-completion'])) {
 269                         if ($activity['thread-completion'] != $item['owner-id']) {
 270                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 271                                 $item['causer-link'] = $actor['url'];
 272                                 $item['causer-id'] = $activity['thread-completion'];
 273                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 274                         } else {
 275                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 276                                 $item['causer-link'] = $item['owner-link'];
 277                                 $item['causer-id'] = $item['owner-id'];
 278                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 279                         }
 280
 281                         $item['owner-link'] = $item['author-link'];
 282                         $item['owner-id'] = $item['author-id'];
 283                 } else {
 284                         $actor = APContact::getByURL($item['owner-link'], false);
 285                         $item['isForum'] = ($actor['type'] == 'Group');
 286                 }
 287
 288                 $item['uri'] = $activity['id'];
 289
 290                 $item['created'] = DateTimeFormat::utc($activity['published']);
 291                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 292                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 293                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 294
 295                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 296                 if (empty($item['uri-id'])) {
 297                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 298                         return [];
 299                 }
 300
 301                 $item = self::processContent($activity, $item);
 302                 if (empty($item)) {
 303                         Logger::info('Message was not processed');
 304                         return [];
 305                 }
 306
 307                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 308
 309                 self::storeAttachments($activity, $item);
 310
 311                 // We received the post via AP, so we set the protocol of the server to AP
 312                 $contact = Contact::getById($item['author-id'], ['gsid']);
 313                 if (!empty($contact['gsid'])) {
 314                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 315                 }
 316
 317                 if ($item['author-id'] != $item['owner-id']) {
 318                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 319                         if (!empty($contact['gsid'])) {
 320                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 321                         }
 322                 }
 323
 324                 return $item;
 325         }
 326
 327         /**
 328          * Delete items
 329          *
 330          * @param array $activity
 331          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 332          * @throws \ImagickException
 333          */
 334         public static function deleteItem($activity)
 335         {
 336                 $owner = Contact::getIdForURL($activity['actor']);
 337
 338                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 339                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 340         }
 341
 342         /**
 343          * Prepare the item array for an activity
 344          *
 345          * @param array $activity Activity array
 346          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 347          * @throws \ImagickException
 348          */
 349         public static function addTag($activity)
 350         {
 351                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 352                         return;
 353                 }
 354
 355                 foreach ($activity['receiver'] as $receiver) {
 356                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 357                         if (!DBA::isResult($item)) {
 358                                 // We don't fetch missing content for this purpose
 359                                 continue;
 360                         }
 361
 362                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 363                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 364                                 continue;
 365                         }
 366
 367                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 368                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 369                 }
 370         }
 371
 372         /**
 373          * Prepare the item array for an activity
 374          *
 375          * @param array  $activity Activity array
 376          * @param string $verb     Activity verb
 377          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 378          * @throws \ImagickException
 379          */
 380         public static function createActivity($activity, $verb)
 381         {
 382                 $item = self::createItem($activity);
 383                 $item['verb'] = $verb;
 384                 $item['thr-parent'] = $activity['object_id'];
 385                 $item['gravity'] = GRAVITY_ACTIVITY;
 386                 unset($item['post-type']);
 387                 $item['object-type'] = Activity\ObjectType::NOTE;
 388
 389                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 390
 391                 self::postItem($activity, $item);
 392         }
 393
 394         /**
 395          * Create an event
 396          *
 397          * @param array $activity Activity array
 398          * @param array $item
 399          * @throws \Exception
 400          */
 401         public static function createEvent($activity, $item)
 402         {
 403                 $event['summary']   = HTML::toBBCode($activity['name']);
 404                 $event['desc']      = HTML::toBBCode($activity['content']);
 405                 $event['start']     = $activity['start-time'];
 406                 $event['finish']    = $activity['end-time'];
 407                 $event['nofinish']  = empty($event['finish']);
 408                 $event['location']  = $activity['location'];
 409                 $event['adjust']    = $activity['adjust'] ?? true;
 410                 $event['cid']       = $item['contact-id'];
 411                 $event['uid']       = $item['uid'];
 412                 $event['uri']       = $item['uri'];
 413                 $event['edited']    = $item['edited'];
 414                 $event['private']   = $item['private'];
 415                 $event['guid']      = $item['guid'];
 416                 $event['plink']     = $item['plink'];
 417                 $event['network']   = $item['network'];
 418                 $event['protocol']  = $item['protocol'];
 419                 $event['direction'] = $item['direction'];
 420                 $event['source']    = $item['source'];
 421
 422                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 423                 $ev = DBA::selectFirst('event', ['id'], $condition);
 424                 if (DBA::isResult($ev)) {
 425                         $event['id'] = $ev['id'];
 426                 }
 427
 428                 $event_id = Event::store($event);
 429                 Logger::info('Event was stored', ['id' => $event_id]);
 430         }
 431
 432         /**
 433          * Process the content
 434          *
 435          * @param array $activity Activity array
 436          * @param array $item
 437          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 438          * @throws \Exception
 439          */
 440         private static function processContent($activity, $item)
 441         {
 442                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 443                         $item['title'] = Markdown::toBBCode($activity['name']);
 444                         $content = Markdown::toBBCode($activity['content']);
 445                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 446                         $item['title'] = $activity['name'];
 447                         $content = $activity['content'];
 448                 } else {
 449                         // By default assume "text/html"
 450                         $item['title'] = HTML::toBBCode($activity['name']);
 451                         $content = HTML::toBBCode($activity['content']);
 452                 }
 453
 454                 if (!empty($activity['languages'])) {
 455                         $item['language'] = self::processLanguages($activity['languages']);
 456                 }
 457
 458                 if (!empty($activity['emojis'])) {
 459                         $content = self::replaceEmojis($content, $activity['emojis']);
 460                 }
 461
 462                 $content = self::convertMentions($content);
 463
 464                 if (!empty($activity['source'])) {
 465                         $item['body'] = $activity['source'];
 466                         $item['raw-body'] = $content;
 467                         $item['body'] = Item::improveSharedDataInBody($item);
 468                 } else {
 469                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 470                                 $item_private = !in_array(0, $activity['item_receiver']);
 471                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 472                                 if (!DBA::isResult($parent)) {
 473                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 474                                         return false;
 475                                 }
 476                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 477                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 478                                         return false;
 479                                 }
 480
 481                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 482                         }
 483                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 484                         $item['raw-body'] = $item['body'] = $content;
 485                 }
 486
 487                 self::storeFromBody($item);
 488                 self::storeTags($item['uri-id'], $activity['tags']);
 489
 490                 $item['location'] = $activity['location'];
 491
 492                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 493                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 494                 }
 495
 496                 $item['app'] = $activity['generator'];
 497
 498                 return $item;
 499         }
 500
 501         /**
 502          * Store hashtags and mentions
 503          *
 504          * @param array $item
 505          */
 506         private static function storeFromBody(array $item)
 507         {
 508                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 509                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 510
 511                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 512         }
 513
 514         /**
 515          * Generate a GUID out of an URL
 516          *
 517          * @param string $url message URL
 518          * @return string with GUID
 519          */
 520         private static function getGUIDByURL(string $url)
 521         {
 522                 $parsed = parse_url($url);
 523
 524                 $host_hash = hash('crc32', $parsed['host']);
 525
 526                 unset($parsed["scheme"]);
 527                 unset($parsed["host"]);
 528
 529                 $path = implode("/", $parsed);
 530
 531                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 532         }
 533
 534         /**
 535          * Creates an item post
 536          *
 537          * @param array $activity Activity data
 538          * @param array $item     item array
 539          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 540          * @throws \ImagickException
 541          */
 542         public static function postItem(array $activity, array $item)
 543         {
 544                 if (empty($item)) {
 545                         return;
 546                 }
 547
 548                 $stored = false;
 549                 ksort($activity['receiver']);
 550
 551                 foreach ($activity['receiver'] as $receiver) {
 552                         if ($receiver == -1) {
 553                                 continue;
 554                         }
 555
 556                         $item['uid'] = $receiver;
 557
 558                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 559                         switch($type) {
 560                                 case Receiver::TARGET_TO:
 561                                         $item['post-reason'] = Item::PR_TO;
 562                                         break;
 563                                 case Receiver::TARGET_CC:
 564                                         $item['post-reason'] = Item::PR_CC;
 565                                         break;
 566                                 case Receiver::TARGET_BTO:
 567                                         $item['post-reason'] = Item::PR_BTO;
 568                                         break;
 569                                 case Receiver::TARGET_BCC:
 570                                         $item['post-reason'] = Item::PR_BCC;
 571                                         break;
 572                                 case Receiver::TARGET_FOLLOWER:
 573                                         $item['post-reason'] = Item::PR_FOLLOWER;
 574                                         break;
 575                                 case Receiver::TARGET_ANSWER:
 576                                         $item['post-reason'] = Item::PR_COMMENT;
 577                                         break;
 578                                 case Receiver::TARGET_GLOBAL:
 579                                         $item['post-reason'] = Item::PR_GLOBAL;
 580                                         break;
 581                                 default:
 582                                         $item['post-reason'] = Item::PR_NONE;
 583                         }
 584
 585                         if (!empty($activity['from-relay'])) {
 586                                 $item['post-reason'] = Item::PR_RELAY;
 587                         } elseif (!empty($activity['thread-completion'])) {
 588                                 $item['post-reason'] = Item::PR_FETCHED;
 589                         }
 590
 591                         if ($item['isForum'] ?? false) {
 592                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 593                         } else {
 594                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 595                         }
 596
 597                         if (($receiver != 0) && empty($item['contact-id'])) {
 598                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 599                         }
 600
 601                         if (!empty($activity['directmessage'])) {
 602                                 self::postMail($activity, $item);
 603                                 continue;
 604                         }
 605
 606                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) &&
 607                                 ($item['post-reason'] == Item::PR_BCC) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 608                                 Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 609                                 continue;
 610                         }
 611
 612                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 613                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 614
 615                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 616                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 617                                 }
 618
 619                                 if ($skip) {
 620                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 621                                         continue;
 622                                 }
 623
 624                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 625                         }
 626
 627                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 628                                 self::createEvent($activity, $item);
 629                         }
 630
 631                         $item_id = Item::insert($item);
 632                         if ($item_id) {
 633                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 634                         } else {
 635                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 636                         }
 637
 638                         if ($item['uid'] == 0) {
 639                                 $stored = $item_id;
 640                         }
 641                 }
 642
 643                 // Store send a follow request for every reshare - but only when the item had been stored
 644                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 645                         $author = APContact::getByURL($item['owner-link'], false);
 646                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 647                         if ($author['type'] != 'Group') {
 648                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 649                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 650                         }
 651                 }
 652         }
 653
 654         /**
 655          * Store tags and mentions into the tag table
 656          *
 657          * @param integer $uriid
 658          * @param array $tags
 659          */
 660         private static function storeTags(int $uriid, array $tags = null)
 661         {
 662                 foreach ($tags as $tag) {
 663                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 664                                 continue;
 665                         }
 666
 667                         $hash = substr($tag['name'], 0, 1);
 668
 669                         if ($tag['type'] == 'Mention') {
 670                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 671                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 672                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 673                                         $tag['name'] = substr($tag['name'], 1);
 674                                 }
 675                                 $type = Tag::IMPLICIT_MENTION;
 676
 677                                 if (!empty($tag['href'])) {
 678                                         $apcontact = APContact::getByURL($tag['href']);
 679                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 680                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 681                                         }
 682                                 }
 683                         } elseif ($tag['type'] == 'Hashtag') {
 684                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 685                                         $tag['name'] = substr($tag['name'], 1);
 686                                 }
 687                                 $type = Tag::HASHTAG;
 688                         }
 689
 690                         if (empty($tag['name'])) {
 691                                 continue;
 692                         }
 693
 694                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 695                 }
 696         }
 697
 698         /**
 699          * Creates an mail post
 700          *
 701          * @param array $activity Activity data
 702          * @param array $item     item array
 703          * @return int|bool New mail table row id or false on error
 704          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 705          */
 706         private static function postMail($activity, $item)
 707         {
 708                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 709                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 710                         return false;
 711                 }
 712
 713                 Logger::info('Direct Message', $item);
 714
 715                 $msg = [];
 716                 $msg['uid'] = $item['uid'];
 717
 718                 $msg['contact-id'] = $item['contact-id'];
 719
 720                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 721                 $msg['from-name'] = $contact['name'];
 722                 $msg['from-url'] = $contact['url'];
 723                 $msg['from-photo'] = $contact['photo'];
 724
 725                 $msg['uri'] = $item['uri'];
 726                 $msg['created'] = $item['created'];
 727
 728                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 729                 if (DBA::isResult($parent)) {
 730                         $msg['parent-uri'] = $parent['parent-uri'];
 731                         $msg['title'] = $parent['title'];
 732                 } else {
 733                         $msg['parent-uri'] = $item['thr-parent'];
 734
 735                         if (!empty($item['title'])) {
 736                                 $msg['title'] = $item['title'];
 737                         } elseif (!empty($item['content-warning'])) {
 738                                 $msg['title'] = $item['content-warning'];
 739                         } else {
 740                                 // Trying to generate a title out of the body
 741                                 $title = $item['body'];
 742
 743                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 744                                         $title = $matches[3];
 745                                 }
 746
 747                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, BBCode::API, true), 0));
 748
 749                                 if (strlen($title) > 20) {
 750                                         $title = substr($title, 0, 20) . '...';
 751                                 }
 752
 753                                 $msg['title'] = $title;
 754                         }
 755                 }
 756                 $msg['body'] = $item['body'];
 757
 758                 return Mail::insert($msg);
 759         }
 760
 761         /**
 762          * Fetches missing posts
 763          *
 764          * @param string $url         message URL
 765          * @param array  $child       activity array with the child of this message
 766          * @param string $relay_actor Relay actor
 767          * @return string fetched message URL
 768          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 769          */
 770         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '')
 771         {
 772                 if (!empty($child['receiver'])) {
 773                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 774                 } else {
 775                         $uid = 0;
 776                 }
 777
 778                 $object = ActivityPub::fetchContent($url, $uid);
 779                 if (empty($object)) {
 780                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url]);
 781                         return '';
 782                 }
 783
 784                 if (empty($object['id'])) {
 785                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
 786                         return '';
 787                 }
 788
 789                 if (!empty($object['actor'])) {
 790                         $object_actor = $object['actor'];
 791                 } elseif (!empty($object['attributedTo'])) {
 792                         $object_actor = $object['attributedTo'];
 793                         if (is_array($object_actor)) {
 794                                 $compacted = JsonLD::compact($object);
 795                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
 796                         }
 797                 } else {
 798                         // Shouldn't happen
 799                         $object_actor = '';
 800                 }
 801
 802                 $signer = [$object_actor];
 803
 804                 if (!empty($child['author'])) {
 805                         $actor = $child['author'];
 806                         $signer[] = $actor;
 807                 } else {
 808                         $actor = $object_actor;
 809                 }
 810
 811                 if (!empty($object['published'])) {
 812                         $published = $object['published'];
 813                 } elseif (!empty($child['published'])) {
 814                         $published = $child['published'];
 815                 } else {
 816                         $published = DateTimeFormat::utcNow();
 817                 }
 818
 819                 $activity = [];
 820                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
 821                 unset($object['@context']);
 822                 $activity['id'] = $object['id'];
 823                 $activity['to'] = $object['to'] ?? [];
 824                 $activity['cc'] = $object['cc'] ?? [];
 825                 $activity['actor'] = $actor;
 826                 $activity['object'] = $object;
 827                 $activity['published'] = $published;
 828                 $activity['type'] = 'Create';
 829
 830                 $ldactivity = JsonLD::compact($activity);
 831
 832                 if (!empty($relay_actor)) {
 833                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
 834                 } elseif (!empty($child['thread-completion'])) {
 835                         $ldactivity['thread-completion'] = $child['thread-completion'];
 836                 } else {
 837                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
 838                 }
 839
 840                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
 841                         return '';
 842                 }
 843
 844                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
 845
 846                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 847
 848                 return $activity['id'];
 849         }
 850
 851         /**
 852          * Test if incoming relay messages should be accepted
 853          *
 854          * @param array $activity activity array
 855          * @param string $id      object ID
 856          * @return boolean true if message is accepted
 857          */
 858         private static function acceptIncomingMessage(array $activity, string $id)
 859         {
 860                 if (empty($activity['as:object'])) {
 861                         Logger::info('No object field in activity - accepted', ['id' => $id]);
 862                         return true;
 863                 }
 864
 865                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
 866                 $uriid = ItemURI::getIdByURI($replyto);
 867                 if (Post::exists(['uri-id' => $uriid])) {
 868                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
 869                         return true;
 870                 }
 871
 872                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
 873                 $authorid = Contact::getIdForURL($attributed_to);
 874
 875                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value'));
 876
 877                 $messageTags = [];
 878                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
 879                 if (!empty($tags)) {
 880                         foreach ($tags as $tag) {
 881                                 if ($tag['type'] != 'Hashtag') {
 882                                         continue;
 883                                 }
 884                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
 885                         }
 886                 }
 887
 888                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
 889         }
 890
 891         /**
 892          * perform a "follow" request
 893          *
 894          * @param array $activity
 895          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 896          * @throws \ImagickException
 897          */
 898         public static function followUser($activity)
 899         {
 900                 $uid = User::getIdForURL($activity['object_id']);
 901                 if (empty($uid)) {
 902                         return;
 903                 }
 904
 905                 $owner = User::getOwnerDataById($uid);
 906                 if (empty($owner)) {
 907                         return;
 908                 }
 909
 910                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 911                 if (!empty($cid)) {
 912                         self::switchContact($cid);
 913                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 914                 }
 915
 916                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 917                         'author-link' => $activity['actor']];
 918
 919                 // Ensure that the contact has got the right network type
 920                 self::switchContact($item['author-id']);
 921
 922                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
 923                 if ($result === true) {
 924                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
 925                 }
 926
 927                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 928                 if (empty($cid)) {
 929                         return;
 930                 }
 931
 932                 if (empty($contact)) {
 933                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 934                 }
 935
 936                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 937         }
 938
 939         /**
 940          * Update the given profile
 941          *
 942          * @param array $activity
 943          * @throws \Exception
 944          */
 945         public static function updatePerson($activity)
 946         {
 947                 if (empty($activity['object_id'])) {
 948                         return;
 949                 }
 950
 951                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
 952                 Contact::updateFromProbeByURL($activity['object_id']);
 953         }
 954
 955         /**
 956          * Delete the given profile
 957          *
 958          * @param array $activity
 959          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 960          */
 961         public static function deletePerson($activity)
 962         {
 963                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 964                         Logger::info('Empty object id or actor.');
 965                         return;
 966                 }
 967
 968                 if ($activity['object_id'] != $activity['actor']) {
 969                         Logger::info('Object id does not match actor.');
 970                         return;
 971                 }
 972
 973                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 974                 while ($contact = DBA::fetch($contacts)) {
 975                         Contact::remove($contact['id']);
 976                 }
 977                 DBA::close($contacts);
 978
 979                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
 980         }
 981
 982         /**
 983          * Accept a follow request
 984          *
 985          * @param array $activity
 986          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 987          * @throws \ImagickException
 988          */
 989         public static function acceptFollowUser($activity)
 990         {
 991                 $uid = User::getIdForURL($activity['object_actor']);
 992                 if (empty($uid)) {
 993                         return;
 994                 }
 995
 996                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 997                 if (empty($cid)) {
 998                         Logger::info('No contact found', ['actor' => $activity['actor']]);
 999                         return;
1000                 }
1001
1002                 self::switchContact($cid);
1003
1004                 $fields = ['pending' => false];
1005
1006                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1007                 if ($contact['rel'] == Contact::FOLLOWER) {
1008                         $fields['rel'] = Contact::FRIEND;
1009                 }
1010
1011                 $condition = ['id' => $cid];
1012                 DBA::update('contact', $fields, $condition);
1013                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1014         }
1015
1016         /**
1017          * Reject a follow request
1018          *
1019          * @param array $activity
1020          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1021          * @throws \ImagickException
1022          */
1023         public static function rejectFollowUser($activity)
1024         {
1025                 $uid = User::getIdForURL($activity['object_actor']);
1026                 if (empty($uid)) {
1027                         return;
1028                 }
1029
1030                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1031                 if (empty($cid)) {
1032                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1033                         return;
1034                 }
1035
1036                 self::switchContact($cid);
1037
1038                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
1039                         Contact::remove($cid);
1040                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1041                 } else {
1042                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1043                 }
1044         }
1045
1046         /**
1047          * Undo activity like "like" or "dislike"
1048          *
1049          * @param array $activity
1050          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1051          * @throws \ImagickException
1052          */
1053         public static function undoActivity($activity)
1054         {
1055                 if (empty($activity['object_id'])) {
1056                         return;
1057                 }
1058
1059                 if (empty($activity['object_actor'])) {
1060                         return;
1061                 }
1062
1063                 $author_id = Contact::getIdForURL($activity['object_actor']);
1064                 if (empty($author_id)) {
1065                         return;
1066                 }
1067
1068                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1069         }
1070
1071         /**
1072          * Activity to remove a follower
1073          *
1074          * @param array $activity
1075          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1076          * @throws \ImagickException
1077          */
1078         public static function undoFollowUser($activity)
1079         {
1080                 $uid = User::getIdForURL($activity['object_object']);
1081                 if (empty($uid)) {
1082                         return;
1083                 }
1084
1085                 $owner = User::getOwnerDataById($uid);
1086                 if (empty($owner)) {
1087                         return;
1088                 }
1089
1090                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1091                 if (empty($cid)) {
1092                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1093                         return;
1094                 }
1095
1096                 self::switchContact($cid);
1097
1098                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1099                 if (!DBA::isResult($contact)) {
1100                         return;
1101                 }
1102
1103                 Contact::removeFollower($owner, $contact);
1104                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1105         }
1106
1107         /**
1108          * Switches a contact to AP if needed
1109          *
1110          * @param integer $cid Contact ID
1111          * @throws \Exception
1112          */
1113         private static function switchContact($cid)
1114         {
1115                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1116                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1117                         return;
1118                 }
1119
1120                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1121                 Contact::updateFromProbe($cid);
1122         }
1123
1124         /**
1125          * Collects implicit mentions like:
1126          * - the author of the parent item
1127          * - all the mentioned conversants in the parent item
1128          *
1129          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1130          * @return array
1131          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1132          */
1133         private static function getImplicitMentionList(array $parent)
1134         {
1135                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1136
1137                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1138
1139                 $implicit_mentions = [];
1140                 if (empty($parent_author['url'])) {
1141                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1142                 } else {
1143                         $implicit_mentions[] = $parent_author['url'];
1144                         $implicit_mentions[] = $parent_author['nurl'];
1145                         $implicit_mentions[] = $parent_author['alias'];
1146                 }
1147
1148                 if (!empty($parent['alias'])) {
1149                         $implicit_mentions[] = $parent['alias'];
1150                 }
1151
1152                 foreach ($parent_terms as $term) {
1153                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1154                         if (!empty($contact['url'])) {
1155                                 $implicit_mentions[] = $contact['url'];
1156                                 $implicit_mentions[] = $contact['nurl'];
1157                                 $implicit_mentions[] = $contact['alias'];
1158                         }
1159                 }
1160
1161                 return $implicit_mentions;
1162         }
1163
1164         /**
1165          * Strips from the body prepended implicit mentions
1166          *
1167          * @param string $body
1168          * @param array $parent
1169          * @return string
1170          */
1171         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1172         {
1173                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1174                         return $body;
1175                 }
1176
1177                 $potential_mentions = self::getImplicitMentionList($parent);
1178
1179                 $kept_mentions = [];
1180
1181                 // Extract one prepended mention at a time from the body
1182                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1183                         if (!in_array($matches[2], $potential_mentions)) {
1184                                 $kept_mentions[] = $matches[1];
1185                         }
1186
1187                         $body = $matches[3];
1188                 }
1189
1190                 // Re-appending the kept mentions to the body after extraction
1191                 $kept_mentions[] = $body;
1192
1193                 return implode('', $kept_mentions);
1194         }
1195 }