src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   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\PageInfo;
  25 use Friendica\Content\Text\BBCode;
  26 use Friendica\Content\Text\HTML;
  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\Item;
  36 use Friendica\Model\ItemURI;
  37 use Friendica\Model\Mail;
  38 use Friendica\Model\Tag;
  39 use Friendica\Model\User;
  40 use Friendica\Model\Post;
  41 use Friendica\Protocol\Activity;
  42 use Friendica\Protocol\ActivityPub;
  43 use Friendica\Protocol\Relay;
  44 use Friendica\Util\DateTimeFormat;
  45 use Friendica\Util\JsonLD;
  46 use Friendica\Util\Strings;
  47
  48 /**
  49  * ActivityPub Processor Protocol class
  50  */
  51 class Processor
  52 {
  53         /**
  54          * Converts mentions from Pleroma into the Friendica format
  55          *
  56          * @param string $body
  57          *
  58          * @return string converted body
  59          */
  60         private static function convertMentions($body)
  61         {
  62                 $URLSearchString = "^\[\]";
  63                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
  64
  65                 return $body;
  66         }
  67
  68         /**
  69          * Replaces emojis in the body
  70          *
  71          * @param array $emojis
  72          * @param string $body
  73          *
  74          * @return string with replaced emojis
  75          */
  76         private static function replaceEmojis($body, array $emojis)
  77         {
  78                 $body = strtr($body,
  79                         array_combine(
  80                                 array_column($emojis, 'name'),
  81                                 array_map(function ($emoji) {
  82                                         return '[class=emoji mastodon][img=' . $emoji['href'] . ']' . $emoji['name'] . '[/img][/class]';
  83                                 }, $emojis)
  84                         )
  85                 );
  86
  87                 return $body;
  88         }
  89
  90         /**
  91          * Store attached media files in the post-media table
  92          *
  93          * @param int $uriid
  94          * @param array $attachment
  95          * @return void
  96          */
  97         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
  98         {
  99                 if (empty($attachment['url'])) {
 100                         return;
 101                 }
 102
 103                 $data = ['uri-id' => $uriid];
 104
 105                 $filetype = strtolower(substr($attachment['mediaType'], 0, strpos($attachment['mediaType'], '/')));
 106                 if ($filetype == 'image') {
 107                         $data['type'] = Post\Media::IMAGE;
 108                 } elseif ($filetype == 'video') {
 109                         $data['type'] = Post\Media::VIDEO;
 110                 } elseif ($filetype == 'audio') {
 111                         $data['type'] = Post\Media::AUDIO;
 112                 } elseif (in_array($attachment['mediaType'], ['application/x-bittorrent', 'application/x-bittorrent;x-scheme-handler/magnet'])) {
 113                         $data['type'] = Post\Media::TORRENT;
 114                 } else {
 115                         Logger::info('Unknown type', ['attachment' => $attachment]);
 116                         return;
 117                 }
 118
 119                 $data['url'] = $attachment['url'];
 120                 $data['mimetype'] = $attachment['mediaType'];
 121                 $data['height'] = $attachment['height'] ?? null;
 122                 $data['size'] = $attachment['size'] ?? null;
 123                 $data['preview'] = $attachment['image'] ?? null;
 124                 $data['description'] = $attachment['name'] ?? null;
 125
 126                 Post\Media::insert($data);
 127         }
 128
 129         /**
 130          * Add attachment data to the item array
 131          *
 132          * @param array   $activity
 133          * @param array   $item
 134          *
 135          * @return array array
 136          */
 137         private static function constructAttachList($activity, $item)
 138         {
 139                 if (empty($activity['attachments'])) {
 140                         return $item;
 141                 }
 142
 143                 foreach ($activity['attachments'] as $attach) {
 144                         switch ($attach['type']) {
 145                                 case 'link':
 146                                         $data = [
 147                                                 'url'      => $attach['url'],
 148                                                 'type'     => $attach['type'],
 149                                                 'title'    => $attach['title'] ?? '',
 150                                                 'text'     => $attach['desc']  ?? '',
 151                                                 'image'    => $attach['image'] ?? '',
 152                                                 'images'   => [],
 153                                                 'keywords' => [],
 154                                         ];
 155                                         $item['body'] = PageInfo::appendDataToBody($item['body'], $data);
 156                                         break;
 157                                 default:
 158                                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 159
 160                                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 161                                         if ($filetype == 'image') {
 162                                                 if (!empty($activity['source'])) {
 163                                                         foreach ([0, 1, 2] as $size) {
 164                                                                 if (preg_match('#/photo/.*-' . $size . '\.#ism', $attach['url']) &&
 165                                                                         strpos(preg_replace('#(/photo/.*)-[012]\.#ism', '$1-' . $size . '.', $activity['source']), $attach['url'])) {
 166                                                                         continue 3;
 167                                                                 }
 168                                                         }
 169                                                         if (strpos($activity['source'], $attach['url'])) {
 170                                                                 continue 2;
 171                                                         }
 172                                                 }
 173
 174                                                 $item['body'] .= "\n";
 175
 176                                                 // image is the preview/thumbnail URL
 177                                                 if (!empty($attach['image'])) {
 178                                                         $item['body'] .= '[url=' . $attach['url'] . ']';
 179                                                         $attach['url'] = $attach['image'];
 180                                                 }
 181
 182                                                 if (empty($attach['name'])) {
 183                                                         $item['body'] .= '[img]' . $attach['url'] . '[/img]';
 184                                                 } else {
 185                                                         $item['body'] .= '[img=' . $attach['url'] . ']' . $attach['name'] . '[/img]';
 186                                                 }
 187
 188                                                 if (!empty($attach['image'])) {
 189                                                         $item['body'] .= '[/url]';
 190                                                 }
 191                                         } elseif ($filetype == 'audio') {
 192                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 193                                                         continue 2;
 194                                                 }
 195
 196                                                 $item['body'] .= "\n[audio]" . $attach['url'] . '[/audio]';
 197                                         } elseif ($filetype == 'video') {
 198                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 199                                                         continue 2;
 200                                                 }
 201
 202                                                 $item['body'] .= "\n[video]" . $attach['url'] . '[/video]';
 203                                         }
 204                         }
 205                 }
 206
 207                 return $item;
 208         }
 209
 210         /**
 211          * Updates a message
 212          *
 213          * @param array $activity Activity array
 214          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 215          */
 216         public static function updateItem($activity)
 217         {
 218                 $item = Item::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity'], ['uri' => $activity['id']]);
 219                 if (!DBA::isResult($item)) {
 220                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 221                         $item = self::createItem($activity);
 222                         self::postItem($activity, $item);
 223                         return;
 224                 }
 225
 226                 $item['changed'] = DateTimeFormat::utcNow();
 227                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 228
 229                 $item = self::processContent($activity, $item);
 230
 231                 $item = self::constructAttachList($activity, $item);
 232
 233                 if (empty($item)) {
 234                         return;
 235                 }
 236
 237                 Item::update($item, ['uri' => $activity['id']]);
 238         }
 239
 240         /**
 241          * Prepares data for a message
 242          *
 243          * @param array $activity Activity array
 244          * @return array Internal item
 245          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 246          * @throws \ImagickException
 247          */
 248         public static function createItem($activity)
 249         {
 250                 $item = [];
 251                 $item['verb'] = Activity::POST;
 252                 $item['thr-parent'] = $activity['reply-to-id'];
 253
 254                 if ($activity['reply-to-id'] == $activity['id']) {
 255                         $item['gravity'] = GRAVITY_PARENT;
 256                         $item['object-type'] = Activity\ObjectType::NOTE;
 257                 } else {
 258                         $item['gravity'] = GRAVITY_COMMENT;
 259                         $item['object-type'] = Activity\ObjectType::COMMENT;
 260                 }
 261
 262                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Item::exists(['uri' => $activity['reply-to-id']])) {
 263                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 264                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 265                 }
 266
 267                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 268
 269                 /// @todo What to do with $activity['context']?
 270                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['thr-parent']])) {
 271                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 272                         return [];
 273                 }
 274
 275                 $item['network'] = Protocol::ACTIVITYPUB;
 276                 $item['author-link'] = $activity['author'];
 277                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 278                 $item['owner-link'] = $activity['actor'];
 279                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 280
 281                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 282                         $item['private'] = Item::UNLISTED;
 283                 } elseif (in_array(0, $activity['receiver'])) {
 284                         $item['private'] = Item::PUBLIC;
 285                 } else {
 286                         $item['private'] = Item::PRIVATE;
 287                 }
 288
 289                 if (!empty($activity['raw'])) {
 290                         $item['source'] = $activity['raw'];
 291                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 292                         $item['conversation-href'] = $activity['context'] ?? '';
 293                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 294
 295                         if (isset($activity['push'])) {
 296                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 297                         }
 298                 }
 299
 300                 $item['isForum'] = false;
 301
 302                 if (!empty($activity['thread-completion'])) {
 303                         if ($activity['thread-completion'] != $item['owner-id']) {
 304                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 305                                 $item['causer-link'] = $actor['url'];
 306                                 $item['causer-id'] = $activity['thread-completion'];
 307                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 308                         } else {
 309                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 310                                 $item['causer-link'] = $item['owner-link'];
 311                                 $item['causer-id'] = $item['owner-id'];
 312                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 313                         }
 314
 315                         $item['owner-link'] = $item['author-link'];
 316                         $item['owner-id'] = $item['author-id'];
 317                 } else {
 318                         $actor = APContact::getByURL($item['owner-link'], false);
 319                         $item['isForum'] = ($actor['type'] == 'Group');
 320                 }
 321
 322                 $item['uri'] = $activity['id'];
 323
 324                 $item['created'] = DateTimeFormat::utc($activity['published']);
 325                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 326                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 327                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 328
 329                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 330                 if (empty($item['uri-id'])) {
 331                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 332                         return [];
 333                 }
 334
 335                 $item = self::processContent($activity, $item);
 336                 if (empty($item)) {
 337                         Logger::info('Message was not processed');
 338                         return [];
 339                 }
 340
 341                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 342
 343                 $item = self::constructAttachList($activity, $item);
 344
 345                 return $item;
 346         }
 347
 348         /**
 349          * Delete items
 350          *
 351          * @param array $activity
 352          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 353          * @throws \ImagickException
 354          */
 355         public static function deleteItem($activity)
 356         {
 357                 $owner = Contact::getIdForURL($activity['actor']);
 358
 359                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 360                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 361         }
 362
 363         /**
 364          * Prepare the item array for an activity
 365          *
 366          * @param array $activity Activity array
 367          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 368          * @throws \ImagickException
 369          */
 370         public static function addTag($activity)
 371         {
 372                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 373                         return;
 374                 }
 375
 376                 foreach ($activity['receiver'] as $receiver) {
 377                         $item = Item::selectFirst(['id', 'uri-id', 'tag', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 378                         if (!DBA::isResult($item)) {
 379                                 // We don't fetch missing content for this purpose
 380                                 continue;
 381                         }
 382
 383                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 384                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 385                                 continue;
 386                         }
 387
 388                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 389                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 390                 }
 391         }
 392
 393         /**
 394          * Prepare the item array for an activity
 395          *
 396          * @param array  $activity Activity array
 397          * @param string $verb     Activity verb
 398          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 399          * @throws \ImagickException
 400          */
 401         public static function createActivity($activity, $verb)
 402         {
 403                 $item = self::createItem($activity);
 404                 $item['verb'] = $verb;
 405                 $item['thr-parent'] = $activity['object_id'];
 406                 $item['gravity'] = GRAVITY_ACTIVITY;
 407                 $item['object-type'] = Activity\ObjectType::NOTE;
 408
 409                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 410
 411                 self::postItem($activity, $item);
 412         }
 413
 414         /**
 415          * Create an event
 416          *
 417          * @param array $activity Activity array
 418          * @param array $item
 419          * @throws \Exception
 420          */
 421         public static function createEvent($activity, $item)
 422         {
 423                 $event['summary']   = HTML::toBBCode($activity['name']);
 424                 $event['desc']      = HTML::toBBCode($activity['content']);
 425                 $event['start']     = $activity['start-time'];
 426                 $event['finish']    = $activity['end-time'];
 427                 $event['nofinish']  = empty($event['finish']);
 428                 $event['location']  = $activity['location'];
 429                 $event['adjust']    = true;
 430                 $event['cid']       = $item['contact-id'];
 431                 $event['uid']       = $item['uid'];
 432                 $event['uri']       = $item['uri'];
 433                 $event['edited']    = $item['edited'];
 434                 $event['private']   = $item['private'];
 435                 $event['guid']      = $item['guid'];
 436                 $event['plink']     = $item['plink'];
 437                 $event['network']   = $item['network'];
 438                 $event['protocol']  = $item['protocol'];
 439                 $event['direction'] = $item['direction'];
 440                 $event['source']    = $item['source'];
 441
 442                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 443                 $ev = DBA::selectFirst('event', ['id'], $condition);
 444                 if (DBA::isResult($ev)) {
 445                         $event['id'] = $ev['id'];
 446                 }
 447
 448                 $event_id = Event::store($event);
 449                 Logger::info('Event was stored', ['id' => $event_id]);
 450         }
 451
 452         /**
 453          * Process the content
 454          *
 455          * @param array $activity Activity array
 456          * @param array $item
 457          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 458          * @throws \Exception
 459          */
 460         private static function processContent($activity, $item)
 461         {
 462                 $item['title'] = HTML::toBBCode($activity['name']);
 463
 464                 $content = HTML::toBBCode($activity['content']);
 465
 466                 if (!empty($activity['emojis'])) {
 467                         $content = self::replaceEmojis($content, $activity['emojis']);
 468                 }
 469
 470                 $content = self::convertMentions($content);
 471
 472                 if (!empty($activity['source'])) {
 473                         $item['body'] = $activity['source'];
 474                         $item['raw-body'] = $content;
 475                 } else {
 476                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 477                                 $item_private = !in_array(0, $activity['item_receiver']);
 478                                 $parent = Item::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 479                                 if (!DBA::isResult($parent)) {
 480                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 481                                         return false;
 482                                 }
 483                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 484                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 485                                         return false;
 486                                 }
 487
 488                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 489                         }
 490                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 491                         $item['raw-body'] = $item['body'] = $content;
 492                 }
 493
 494                 self::storeFromBody($item);
 495                 self::storeTags($item['uri-id'], $activity['tags']);
 496
 497                 $item['location'] = $activity['location'];
 498
 499                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 500                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 501                 }
 502
 503                 $item['app'] = $activity['generator'];
 504
 505                 return $item;
 506         }
 507
 508         /**
 509          * Store hashtags and mentions
 510          *
 511          * @param array $item
 512          */
 513         private static function storeFromBody(array $item)
 514         {
 515                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 516                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 517
 518                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 519         }
 520
 521         /**
 522          * Generate a GUID out of an URL
 523          *
 524          * @param string $url message URL
 525          * @return string with GUID
 526          */
 527         private static function getGUIDByURL(string $url)
 528         {
 529                 $parsed = parse_url($url);
 530
 531                 $host_hash = hash('crc32', $parsed['host']);
 532
 533                 unset($parsed["scheme"]);
 534                 unset($parsed["host"]);
 535
 536                 $path = implode("/", $parsed);
 537
 538                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 539         }
 540
 541         /**
 542          * Creates an item post
 543          *
 544          * @param array $activity Activity data
 545          * @param array $item     item array
 546          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 547          * @throws \ImagickException
 548          */
 549         public static function postItem(array $activity, array $item)
 550         {
 551                 if (empty($item)) {
 552                         return;
 553                 }
 554
 555                 $stored = false;
 556                 ksort($activity['receiver']);
 557
 558                 foreach ($activity['receiver'] as $receiver) {
 559                         if ($receiver == -1) {
 560                                 continue;
 561                         }
 562
 563                         $item['uid'] = $receiver;
 564
 565                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 566                         switch($type) {
 567                                 case Receiver::TARGET_TO:
 568                                         $item['post-type'] = Item::PT_TO;
 569                                         break;
 570                                 case Receiver::TARGET_CC:
 571                                         $item['post-type'] = Item::PT_CC;
 572                                         break;
 573                                 case Receiver::TARGET_BTO:
 574                                         $item['post-type'] = Item::PT_BTO;
 575                                         break;
 576                                 case Receiver::TARGET_BCC:
 577                                         $item['post-type'] = Item::PT_BCC;
 578                                         break;
 579                                 case Receiver::TARGET_FOLLOWER:
 580                                         $item['post-type'] = Item::PT_FOLLOWER;
 581                                         break;
 582                                 case Receiver::TARGET_ANSWER:
 583                                         $item['post-type'] = Item::PT_COMMENT;
 584                                         break;
 585                                 case Receiver::TARGET_GLOBAL:
 586                                         $item['post-type'] = Item::PT_GLOBAL;
 587                                         break;
 588                                 default:
 589                                         $item['post-type'] = Item::PT_ARTICLE;
 590                         }
 591
 592                         if (!empty($activity['from-relay'])) {
 593                                 $item['post-type'] = Item::PT_RELAY;
 594                         } elseif (!empty($activity['thread-completion'])) {
 595                                 $item['post-type'] = Item::PT_FETCHED;
 596                         }
 597
 598                         if ($item['isForum'] ?? false) {
 599                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 600                         } else {
 601                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 602                         }
 603
 604                         if (($receiver != 0) && empty($item['contact-id'])) {
 605                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 606                         }
 607
 608                         if (!empty($activity['directmessage'])) {
 609                                 self::postMail($activity, $item);
 610                                 continue;
 611                         }
 612
 613                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 614                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 615
 616                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 617                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 618                                 }
 619
 620                                 if ($skip) {
 621                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 622                                         continue;
 623                                 }
 624
 625                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 626                         }
 627
 628                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 629                                 self::createEvent($activity, $item);
 630                         }
 631
 632                         $item_id = Item::insert($item);
 633                         if ($item_id) {
 634                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 635                         } else {
 636                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 637                         }
 638
 639                         if ($item['uid'] == 0) {
 640                                 $stored = $item_id;
 641                         }
 642                 }
 643
 644                 // Store send a follow request for every reshare - but only when the item had been stored
 645                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 646                         $author = APContact::getByURL($item['owner-link'], false);
 647                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 648                         if ($author['type'] != 'Group') {
 649                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 650                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 651                         }
 652                 }
 653         }
 654
 655         /**
 656          * Store tags and mentions into the tag table
 657          *
 658          * @param integer $uriid
 659          * @param array $tags
 660          */
 661         private static function storeTags(int $uriid, array $tags = null)
 662         {
 663                 foreach ($tags as $tag) {
 664                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 665                                 continue;
 666                         }
 667
 668                         $hash = substr($tag['name'], 0, 1);
 669
 670                         if ($tag['type'] == 'Mention') {
 671                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 672                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 673                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 674                                         $tag['name'] = substr($tag['name'], 1);
 675                                 }
 676                                 $type = Tag::IMPLICIT_MENTION;
 677
 678                                 if (!empty($tag['href'])) {
 679                                         $apcontact = APContact::getByURL($tag['href']);
 680                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 681                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 682                                         }
 683                                 }
 684                         } elseif ($tag['type'] == 'Hashtag') {
 685                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 686                                         $tag['name'] = substr($tag['name'], 1);
 687                                 }
 688                                 $type = Tag::HASHTAG;
 689                         }
 690
 691                         if (empty($tag['name'])) {
 692                                 continue;
 693                         }
 694
 695                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 696                 }
 697         }
 698
 699         /**
 700          * Creates an mail post
 701          *
 702          * @param array $activity Activity data
 703          * @param array $item     item array
 704          * @return int|bool New mail table row id or false on error
 705          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 706          */
 707         private static function postMail($activity, $item)
 708         {
 709                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 710                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 711                         return false;
 712                 }
 713
 714                 Logger::info('Direct Message', $item);
 715
 716                 $msg = [];
 717                 $msg['uid'] = $item['uid'];
 718
 719                 $msg['contact-id'] = $item['contact-id'];
 720
 721                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 722                 $msg['from-name'] = $contact['name'];
 723                 $msg['from-url'] = $contact['url'];
 724                 $msg['from-photo'] = $contact['photo'];
 725
 726                 $msg['uri'] = $item['uri'];
 727                 $msg['created'] = $item['created'];
 728
 729                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 730                 if (DBA::isResult($parent)) {
 731                         $msg['parent-uri'] = $parent['parent-uri'];
 732                         $msg['title'] = $parent['title'];
 733                 } else {
 734                         $msg['parent-uri'] = $item['thr-parent'];
 735
 736                         if (!empty($item['title'])) {
 737                                 $msg['title'] = $item['title'];
 738                         } elseif (!empty($item['content-warning'])) {
 739                                 $msg['title'] = $item['content-warning'];
 740                         } else {
 741                                 // Trying to generate a title out of the body
 742                                 $title = $item['body'];
 743
 744                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 745                                         $title = $matches[3];
 746                                 }
 747
 748                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, BBCode::API, true), 0));
 749
 750                                 if (strlen($title) > 20) {
 751                                         $title = substr($title, 0, 20) . '...';
 752                                 }
 753
 754                                 $msg['title'] = $title;
 755                         }
 756                 }
 757                 $msg['body'] = $item['body'];
 758
 759                 return Mail::insert($msg);
 760         }
 761
 762         /**
 763          * Fetches missing posts
 764          *
 765          * @param string $url         message URL
 766          * @param array  $child       activity array with the child of this message
 767          * @param string $relay_actor Relay actor
 768          * @return string fetched message URL
 769          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 770          */
 771         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '')
 772         {
 773                 if (!empty($child['receiver'])) {
 774                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 775                 } else {
 776                         $uid = 0;
 777                 }
 778
 779                 $object = ActivityPub::fetchContent($url, $uid);
 780                 if (empty($object)) {
 781                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 782                         return '';
 783                 }
 784
 785                 if (empty($object['id'])) {
 786                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 787                         return '';
 788                 }
 789
 790                 if (!empty($object['actor'])) {
 791                         $object_actor = $object['actor'];
 792                 } elseif (!empty($object['attributedTo'])) {
 793                         $object_actor = $object['attributedTo'];
 794                         if (is_array($object_actor)) {
 795                                 $compacted = JsonLD::compact($object);
 796                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
 797                         }
 798                 } else {
 799                         // Shouldn't happen
 800                         $object_actor = '';
 801                 }
 802
 803                 $signer = [$object_actor];
 804
 805                 if (!empty($child['author'])) {
 806                         $actor = $child['author'];
 807                         $signer[] = $actor;
 808                 } else {
 809                         $actor = $object_actor;
 810                 }
 811
 812                 if (!empty($object['published'])) {
 813                         $published = $object['published'];
 814                 } elseif (!empty($child['published'])) {
 815                         $published = $child['published'];
 816                 } else {
 817                         $published = DateTimeFormat::utcNow();
 818                 }
 819
 820                 $activity = [];
 821                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
 822                 unset($object['@context']);
 823                 $activity['id'] = $object['id'];
 824                 $activity['to'] = $object['to'] ?? [];
 825                 $activity['cc'] = $object['cc'] ?? [];
 826                 $activity['actor'] = $actor;
 827                 $activity['object'] = $object;
 828                 $activity['published'] = $published;
 829                 $activity['type'] = 'Create';
 830
 831                 $ldactivity = JsonLD::compact($activity);
 832
 833                 if (!empty($relay_actor)) {
 834                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
 835                 } elseif (!empty($child['thread-completion'])) {
 836                         $ldactivity['thread-completion'] = $child['thread-completion'];
 837                 } else {
 838                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
 839                 }
 840
 841                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
 842                         return '';
 843                 }
 844
 845                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
 846
 847                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 848
 849                 return $activity['id'];
 850         }
 851
 852         /**
 853          * Test if incoming relay messages should be accepted
 854          *
 855          * @param array $activity activity array
 856          * @param string $id      object ID
 857          * @return boolean true if message is accepted
 858          */
 859         private static function acceptIncomingMessage(array $activity, string $id)
 860         {
 861                 if (empty($activity['as:object'])) {
 862                         Logger::info('No object field in activity - accepted', ['id' => $id]);
 863                         return true;
 864                 }
 865
 866                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
 867                 if (Item::exists(['uri' => $replyto])) {
 868                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, '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::log('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'], 'item-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 }