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\Search;
  39 use Friendica\Model\Tag;
  40 use Friendica\Model\User;
  41 use Friendica\Protocol\Activity;
  42 use Friendica\Protocol\ActivityPub;
  43 use Friendica\Util\DateTimeFormat;
  44 use Friendica\Util\JsonLD;
  45 use Friendica\Util\Strings;
  46 use Text_LanguageDetect;
  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 $emojis)
  77         {
  78                 foreach ($emojis as $emoji) {
  79                         $replace = '[class=emoji mastodon][img=' . $emoji['href'] . ']' . $emoji['name'] . '[/img][/class]';
  80                         $body = str_replace($emoji['name'], $replace, $body);
  81                 }
  82                 return $body;
  83         }
  84
  85         /**
  86          * Add attachment data to the item array
  87          *
  88          * @param array   $activity
  89          * @param array   $item
  90          *
  91          * @return array array
  92          */
  93         private static function constructAttachList($activity, $item)
  94         {
  95                 if (empty($activity['attachments'])) {
  96                         return $item;
  97                 }
  98
  99                 foreach ($activity['attachments'] as $attach) {
 100                         switch ($attach['type']) {
 101                                 case 'link':
 102                                         $data = [
 103                                                 'url'      => $attach['url'],
 104                                                 'type'     => $attach['type'],
 105                                                 'title'    => $attach['title'] ?? '',
 106                                                 'text'     => $attach['desc']  ?? '',
 107                                                 'image'    => $attach['image'] ?? '',
 108                                                 'images'   => [],
 109                                                 'keywords' => [],
 110                                         ];
 111                                         $item['body'] = PageInfo::appendDataToBody($item['body'], $data);
 112                                         break;
 113                                 default:
 114                                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 115                                         if ($filetype == 'image') {
 116                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 117                                                         continue 2;
 118                                                 }
 119
 120                                                 $item['body'] .= "\n";
 121
 122                                                 // image is the preview/thumbnail URL
 123                                                 if (!empty($attach['image'])) {
 124                                                         $item['body'] .= '[url=' . $attach['url'] . ']';
 125                                                         $attach['url'] = $attach['image'];
 126                                                 }
 127
 128                                                 if (empty($attach['name'])) {
 129                                                         $item['body'] .= '[img]' . $attach['url'] . '[/img]';
 130                                                 } else {
 131                                                         $item['body'] .= '[img=' . $attach['url'] . ']' . $attach['name'] . '[/img]';
 132                                                 }
 133
 134                                                 if (!empty($attach['image'])) {
 135                                                         $item['body'] .= '[/url]';
 136                                                 }
 137                                         } elseif ($filetype == 'audio') {
 138                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 139                                                         continue 2;
 140                                                 }
 141
 142                                                 $item['body'] .= "\n[audio]" . $attach['url'] . '[/audio]';
 143                                         } elseif ($filetype == 'video') {
 144                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 145                                                         continue 2;
 146                                                 }
 147
 148                                                 $item['body'] .= "\n[video]" . $attach['url'] . '[/video]';
 149                                         } else {
 150                                                 if (!empty($item["attach"])) {
 151                                                         $item["attach"] .= ',';
 152                                                 } else {
 153                                                         $item["attach"] = '';
 154                                                 }
 155
 156                                                 $item["attach"] .= '[attach]href="' . $attach['url'] . '" length="' . ($attach['length'] ?? '0') . '" type="' . $attach['mediaType'] . '" title="' . ($attach['name'] ?? '') . '"[/attach]';
 157                                         }
 158                         }
 159                 }
 160
 161                 return $item;
 162         }
 163
 164         /**
 165          * Updates a message
 166          *
 167          * @param array $activity Activity array
 168          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 169          */
 170         public static function updateItem($activity)
 171         {
 172                 $item = Item::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity'], ['uri' => $activity['id']]);
 173                 if (!DBA::isResult($item)) {
 174                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 175                         $item = self::createItem($activity);
 176                         self::postItem($activity, $item);
 177                         return;
 178                 }
 179
 180                 $item['changed'] = DateTimeFormat::utcNow();
 181                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 182
 183                 $item = self::processContent($activity, $item);
 184                 if (empty($item)) {
 185                         return;
 186                 }
 187
 188                 Item::update($item, ['uri' => $activity['id']]);
 189         }
 190
 191         /**
 192          * Prepares data for a message
 193          *
 194          * @param array $activity Activity array
 195          * @return array Internal item
 196          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 197          * @throws \ImagickException
 198          */
 199         public static function createItem($activity)
 200         {
 201                 $item = [];
 202                 $item['verb'] = Activity::POST;
 203                 $item['thr-parent'] = $activity['reply-to-id'];
 204
 205                 if ($activity['reply-to-id'] == $activity['id']) {
 206                         $item['gravity'] = GRAVITY_PARENT;
 207                         $item['object-type'] = Activity\ObjectType::NOTE;
 208                 } else {
 209                         $item['gravity'] = GRAVITY_COMMENT;
 210                         $item['object-type'] = Activity\ObjectType::COMMENT;
 211                 }
 212
 213                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Item::exists(['uri' => $activity['reply-to-id']])) {
 214                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 215                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 216                 }
 217
 218                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 219
 220                 /// @todo What to do with $activity['context']?
 221                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['thr-parent']])) {
 222                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 223                         return [];
 224                 }
 225
 226                 $item['network'] = Protocol::ACTIVITYPUB;
 227                 $item['author-link'] = $activity['author'];
 228                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 229                 $item['owner-link'] = $activity['actor'];
 230                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 231
 232                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 233                         $item['private'] = Item::UNLISTED;
 234                 } elseif (in_array(0, $activity['receiver'])) {
 235                         $item['private'] = Item::PUBLIC;
 236                 } else {
 237                         $item['private'] = Item::PRIVATE;
 238                 }
 239
 240                 if (!empty($activity['raw'])) {
 241                         $item['source'] = $activity['raw'];
 242                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 243                         $item['conversation-href'] = $activity['context'] ?? '';
 244                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 245
 246                         if (isset($activity['push'])) {
 247                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 248                         }
 249                 }
 250
 251                 $item['isForum'] = false;
 252
 253                 if (!empty($activity['thread-completion'])) {
 254                         // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 255                         $item['causer-link'] = $item['owner-link'];
 256                         $item['causer-id'] = $item['owner-id'];
 257
 258                         Logger::info('Ignoring actor because of thread completion.', ['actor' => $item['owner-link']]);
 259                         $item['owner-link'] = $item['author-link'];
 260                         $item['owner-id'] = $item['author-id'];
 261                 } else {
 262                         $actor = APContact::getByURL($item['owner-link'], false);
 263                         $item['isForum'] = ($actor['type'] == 'Group');
 264                 }
 265
 266                 $item['uri'] = $activity['id'];
 267
 268                 $item['created'] = DateTimeFormat::utc($activity['published']);
 269                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 270                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 271                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 272
 273                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 274
 275                 $item = self::processContent($activity, $item);
 276                 if (empty($item)) {
 277                         Logger::info('Message was not processed');
 278                         return [];
 279                 }
 280
 281                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 282
 283                 $item = self::constructAttachList($activity, $item);
 284
 285                 return $item;
 286         }
 287
 288         /**
 289          * Delete items
 290          *
 291          * @param array $activity
 292          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 293          * @throws \ImagickException
 294          */
 295         public static function deleteItem($activity)
 296         {
 297                 $owner = Contact::getIdForURL($activity['actor']);
 298
 299                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 300                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 301         }
 302
 303         /**
 304          * Prepare the item array for an activity
 305          *
 306          * @param array $activity Activity array
 307          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 308          * @throws \ImagickException
 309          */
 310         public static function addTag($activity)
 311         {
 312                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 313                         return;
 314                 }
 315
 316                 foreach ($activity['receiver'] as $receiver) {
 317                         $item = Item::selectFirst(['id', 'uri-id', 'tag', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 318                         if (!DBA::isResult($item)) {
 319                                 // We don't fetch missing content for this purpose
 320                                 continue;
 321                         }
 322
 323                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 324                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 325                                 continue;
 326                         }
 327
 328                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 329                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 330                 }
 331         }
 332
 333         /**
 334          * Prepare the item array for an activity
 335          *
 336          * @param array  $activity Activity array
 337          * @param string $verb     Activity verb
 338          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 339          * @throws \ImagickException
 340          */
 341         public static function createActivity($activity, $verb)
 342         {
 343                 $item = self::createItem($activity);
 344                 $item['verb'] = $verb;
 345                 $item['thr-parent'] = $activity['object_id'];
 346                 $item['gravity'] = GRAVITY_ACTIVITY;
 347                 $item['object-type'] = Activity\ObjectType::NOTE;
 348
 349                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 350
 351                 self::postItem($activity, $item);
 352         }
 353
 354         /**
 355          * Create an event
 356          *
 357          * @param array $activity Activity array
 358          * @param array $item
 359          * @throws \Exception
 360          */
 361         public static function createEvent($activity, $item)
 362         {
 363                 $event['summary']  = HTML::toBBCode($activity['name']);
 364                 $event['desc']     = HTML::toBBCode($activity['content']);
 365                 $event['start']    = $activity['start-time'];
 366                 $event['finish']   = $activity['end-time'];
 367                 $event['nofinish'] = empty($event['finish']);
 368                 $event['location'] = $activity['location'];
 369                 $event['adjust']   = true;
 370                 $event['cid']      = $item['contact-id'];
 371                 $event['uid']      = $item['uid'];
 372                 $event['uri']      = $item['uri'];
 373                 $event['edited']   = $item['edited'];
 374                 $event['private']  = $item['private'];
 375                 $event['guid']     = $item['guid'];
 376                 $event['plink']    = $item['plink'];
 377
 378                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 379                 $ev = DBA::selectFirst('event', ['id'], $condition);
 380                 if (DBA::isResult($ev)) {
 381                         $event['id'] = $ev['id'];
 382                 }
 383
 384                 $event_id = Event::store($event);
 385                 Logger::info('Event was stored', ['id' => $event_id]);
 386         }
 387
 388         /**
 389          * Process the content
 390          *
 391          * @param array $activity Activity array
 392          * @param array $item
 393          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 394          * @throws \Exception
 395          */
 396         private static function processContent($activity, $item)
 397         {
 398                 $item['title'] = HTML::toBBCode($activity['name']);
 399
 400                 if (!empty($activity['source'])) {
 401                         $item['body'] = $activity['source'];
 402                 } else {
 403                         $content = HTML::toBBCode($activity['content']);
 404
 405                         if (!empty($activity['emojis'])) {
 406                                 $content = self::replaceEmojis($content, $activity['emojis']);
 407                         }
 408
 409                         $content = self::convertMentions($content);
 410
 411                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 412                                 $item_private = !in_array(0, $activity['item_receiver']);
 413                                 $parent = Item::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 414                                 if (!DBA::isResult($parent)) {
 415                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 416                                         return false;
 417                                 }
 418                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 419                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 420                                         return false;
 421                                 }
 422
 423                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 424                         }
 425                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 426                         $item['body'] = $content;
 427                 }
 428
 429                 self::storeFromBody($item);
 430                 self::storeTags($item['uri-id'], $activity['tags']);
 431
 432                 $item['location'] = $activity['location'];
 433
 434                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 435                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 436                 }
 437
 438                 $item['app'] = $activity['generator'];
 439
 440                 return $item;
 441         }
 442
 443         /**
 444          * Store hashtags and mentions
 445          *
 446          * @param array $item
 447          */
 448         private static function storeFromBody(array $item)
 449         {
 450                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 451                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 452
 453                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 454         }
 455
 456         /**
 457          * Generate a GUID out of an URL
 458          *
 459          * @param string $url message URL
 460          * @return string with GUID
 461          */
 462         private static function getGUIDByURL(string $url)
 463         {
 464                 $parsed = parse_url($url);
 465
 466                 $host_hash = hash('crc32', $parsed['host']);
 467
 468                 unset($parsed["scheme"]);
 469                 unset($parsed["host"]);
 470
 471                 $path = implode("/", $parsed);
 472
 473                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 474         }
 475
 476         /**
 477          * Creates an item post
 478          *
 479          * @param array $activity Activity data
 480          * @param array $item     item array
 481          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 482          * @throws \ImagickException
 483          */
 484         public static function postItem(array $activity, array $item)
 485         {
 486                 if (empty($item)) {
 487                         return;
 488                 }
 489
 490                 $stored = false;
 491                 ksort($activity['receiver']);
 492
 493                 foreach ($activity['receiver'] as $receiver) {
 494                         if ($receiver == -1) {
 495                                 continue;
 496                         }
 497
 498                         $item['uid'] = $receiver;
 499
 500                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 501                         switch($type) {
 502                                 case Receiver::TARGET_TO:
 503                                         $item['post-type'] = Item::PT_TO;
 504                                         break;
 505                                 case Receiver::TARGET_CC:
 506                                         $item['post-type'] = Item::PT_CC;
 507                                         break;
 508                                 case Receiver::TARGET_BTO:
 509                                         $item['post-type'] = Item::PT_BTO;
 510                                         break;
 511                                 case Receiver::TARGET_BCC:
 512                                         $item['post-type'] = Item::PT_BCC;
 513                                         break;
 514                                 case Receiver::TARGET_FOLLOWER:
 515                                         $item['post-type'] = Item::PT_FOLLOWER;
 516                                         break;
 517                                 case Receiver::TARGET_ANSWER:
 518                                         $item['post-type'] = Item::PT_COMMENT;
 519                                         break;
 520                                 case Receiver::TARGET_GLOBAL:
 521                                         $item['post-type'] = Item::PT_GLOBAL;
 522                                         break;
 523                                 default:
 524                                         $item['post-type'] = Item::PT_ARTICLE;
 525                         }
 526
 527                         if (!empty($activity['from-relay'])) {
 528                                 $item['post-type'] = Item::PT_RELAY;
 529                         } elseif (!empty($activity['thread-completion'])) {
 530                                 $item['post-type'] = Item::PT_FETCHED;
 531                         }
 532
 533                         if (!empty($activity['from-relay'])) {
 534                                 $item['causer-id'] = $activity['from-relay'];
 535                         }
 536
 537                         if ($item['isForum'] ?? false) {
 538                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 539                         } else {
 540                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 541                         }
 542
 543                         if (($receiver != 0) && empty($item['contact-id'])) {
 544                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 545                         }
 546
 547                         if (!empty($activity['directmessage'])) {
 548                                 self::postMail($activity, $item);
 549                                 continue;
 550                         }
 551
 552                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 553                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 554
 555                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 556                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 557                                 }
 558
 559                                 if ($skip) {
 560                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 561                                         continue;
 562                                 }
 563
 564                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 565                         }
 566
 567                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 568                                 self::createEvent($activity, $item);
 569                         }
 570
 571                         $item_id = Item::insert($item);
 572                         if ($item_id) {
 573                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 574                         } else {
 575                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 576                         }
 577
 578                         if ($item['uid'] == 0) {
 579                                 $stored = $item_id;
 580                         }
 581                 }
 582
 583                 // Store send a follow request for every reshare - but only when the item had been stored
 584                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 585                         $author = APContact::getByURL($item['owner-link'], false);
 586                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 587                         if ($author['type'] != 'Group') {
 588                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 589                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 590                         }
 591                 }
 592         }
 593
 594         /**
 595          * Store tags and mentions into the tag table
 596          *
 597          * @param integer $uriid
 598          * @param array $tags
 599          */
 600         private static function storeTags(int $uriid, array $tags = null)
 601         {
 602                 foreach ($tags as $tag) {
 603                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 604                                 continue;
 605                         }
 606
 607                         $hash = substr($tag['name'], 0, 1);
 608
 609                         if ($tag['type'] == 'Mention') {
 610                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 611                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 612                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 613                                         $tag['name'] = substr($tag['name'], 1);
 614                                 }
 615                                 $type = Tag::IMPLICIT_MENTION;
 616
 617                                 if (!empty($tag['href'])) {
 618                                         $apcontact = APContact::getByURL($tag['href']);
 619                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 620                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 621                                         }
 622                                 }
 623                         } elseif ($tag['type'] == 'Hashtag') {
 624                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 625                                         $tag['name'] = substr($tag['name'], 1);
 626                                 }
 627                                 $type = Tag::HASHTAG;
 628                         }
 629
 630                         if (empty($tag['name'])) {
 631                                 continue;
 632                         }
 633
 634                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 635                 }
 636         }
 637
 638         /**
 639          * Creates an mail post
 640          *
 641          * @param array $activity Activity data
 642          * @param array $item     item array
 643          * @return int|bool New mail table row id or false on error
 644          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 645          */
 646         private static function postMail($activity, $item)
 647         {
 648                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 649                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 650                         return false;
 651                 }
 652
 653                 Logger::info('Direct Message', $item);
 654
 655                 $msg = [];
 656                 $msg['uid'] = $item['uid'];
 657
 658                 $msg['contact-id'] = $item['contact-id'];
 659
 660                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 661                 $msg['from-name'] = $contact['name'];
 662                 $msg['from-url'] = $contact['url'];
 663                 $msg['from-photo'] = $contact['photo'];
 664
 665                 $msg['uri'] = $item['uri'];
 666                 $msg['created'] = $item['created'];
 667
 668                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 669                 if (DBA::isResult($parent)) {
 670                         $msg['parent-uri'] = $parent['parent-uri'];
 671                         $msg['title'] = $parent['title'];
 672                 } else {
 673                         $msg['parent-uri'] = $item['thr-parent'];
 674
 675                         if (!empty($item['title'])) {
 676                                 $msg['title'] = $item['title'];
 677                         } elseif (!empty($item['content-warning'])) {
 678                                 $msg['title'] = $item['content-warning'];
 679                         } else {
 680                                 // Trying to generate a title out of the body
 681                                 $title = $item['body'];
 682
 683                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 684                                         $title = $matches[3];
 685                                 }
 686
 687                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, BBCode::API, true), 0));
 688
 689                                 if (strlen($title) > 20) {
 690                                         $title = substr($title, 0, 20) . '...';
 691                                 }
 692
 693                                 $msg['title'] = $title;
 694                         }
 695                 }
 696                 $msg['body'] = $item['body'];
 697
 698                 return Mail::insert($msg);
 699         }
 700
 701         /**
 702          * Fetches missing posts
 703          *
 704          * @param string $url         message URL
 705          * @param array  $child       activity array with the child of this message
 706          * @param string $relay_actor Relay actor
 707          * @return string fetched message URL
 708          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 709          */
 710         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '')
 711         {
 712                 if (!empty($child['receiver'])) {
 713                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 714                 } else {
 715                         $uid = 0;
 716                 }
 717
 718                 $object = ActivityPub::fetchContent($url, $uid);
 719                 if (empty($object)) {
 720                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 721                         return '';
 722                 }
 723
 724                 if (empty($object['id'])) {
 725                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 726                         return '';
 727                 }
 728
 729                 if (!empty($object['actor'])) {
 730                         $object_actor = $object['actor'];
 731                 } elseif (!empty($object['attributedTo'])) {
 732                         $object_actor = $object['attributedTo'];
 733                 } else {
 734                         // Shouldn't happen
 735                         $object_actor = '';
 736                 }
 737
 738                 $signer = [$object_actor];
 739
 740                 if (!empty($child['author'])) {
 741                         $actor = $child['author'];
 742                         $signer[] = $actor;
 743                 } else {
 744                         $actor = $object_actor;
 745                 }
 746
 747                 if (!empty($object['published'])) {
 748                         $published = $object['published'];
 749                 } elseif (!empty($child['published'])) {
 750                         $published = $child['published'];
 751                 } else {
 752                         $published = DateTimeFormat::utcNow();
 753                 }
 754
 755                 $activity = [];
 756                 $activity['@context'] = $object['@context'];
 757                 unset($object['@context']);
 758                 $activity['id'] = $object['id'];
 759                 $activity['to'] = $object['to'] ?? [];
 760                 $activity['cc'] = $object['cc'] ?? [];
 761                 $activity['actor'] = $actor;
 762                 $activity['object'] = $object;
 763                 $activity['published'] = $published;
 764                 $activity['type'] = 'Create';
 765
 766                 $ldactivity = JsonLD::compact($activity);
 767
 768                 $ldactivity['thread-completion'] = true;
 769                 $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
 770
 771                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
 772                         return '';
 773                 }
 774
 775                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
 776
 777                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 778
 779                 return $activity['id'];
 780         }
 781
 782         /**
 783          * Test if incoming relay messages should be accepted
 784          *
 785          * @param array $activity activity array
 786          * @param string $id      object ID
 787          * @return boolean true if message is accepted
 788          */
 789         private static function acceptIncomingMessage(array $activity, string $id)
 790         {
 791                 if (empty($activity['as:object'])) {
 792                         Logger::info('No object field in activity - accepted', ['id' => $id]);
 793                         return true;
 794                 }
 795
 796                 $config = DI::config();
 797
 798                 $subscribe = $config->get('system', 'relay_subscribe', false);
 799                 if ($subscribe) {
 800                         $scope = $config->get('system', 'relay_scope', SR_SCOPE_ALL);
 801                 } else {
 802                         $scope = SR_SCOPE_NONE;
 803                 }
 804
 805                 if ($scope == SR_SCOPE_ALL) {
 806                         Logger::info('Server accept all posts - accepted', ['id' => $id]);
 807                         return true;
 808                 }
 809
 810                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
 811                 if (Item::exists(['uri' => $replyto])) {
 812                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'replyto' => $replyto]);
 813                         return true;
 814                 }
 815
 816                 if ($scope == SR_SCOPE_NONE) {
 817                         Logger::info('Server does not accept relay posts - rejected', ['id' => $id]);
 818                         return false;
 819                 }
 820
 821                 $messageTags = [];
 822                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
 823                 if (!empty($tags)) {
 824                         foreach ($tags as $tag) {
 825                                 if ($tag['type'] != 'Hashtag') {
 826                                         continue;
 827                                 }
 828                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
 829                         }
 830                 }
 831
 832                 $systemTags = [];
 833                 $userTags = [];
 834
 835                 if ($scope == SR_SCOPE_TAGS) {
 836                         $server_tags = $config->get('system', 'relay_server_tags', []);
 837                         $tagitems = explode(',', mb_strtolower($server_tags));
 838
 839                         foreach ($tagitems AS $tag) {
 840                                 $systemTags[] = trim($tag, '# ');
 841                         }
 842
 843                         if ($config->get('system', 'relay_user_tags')) {
 844                                 $userTags = Search::getUserTags();
 845                         }
 846                 }
 847
 848                 $content = mb_strtolower(BBCode::toPlaintext(HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value')), false));
 849
 850                 $tagList = array_unique(array_merge($systemTags, $userTags));
 851                 foreach ($messageTags as $tag) {
 852                         if (in_array($tag, $tagList)) {
 853                                 Logger::info('Subscribed hashtag found - accepted', ['id' => $id, 'hashtag' => $tag]);
 854                                 return true;
 855                         }
 856                         // We check with "strpos" for performance issues. Only when this is true, the regular expression check is used
 857                         // RegExp is taken from here: https://medium.com/@shiba1014/regex-word-boundaries-with-unicode-207794f6e7ed
 858                         if ((strpos($content, $tag) !== false) && preg_match('/(?<=[\s,.:;"\']|^)' . preg_quote($tag, '/') . '(?=[\s,.:;"\']|$)/', $content)) {
 859                                 Logger::info('Subscribed hashtag found in content - accepted', ['id' => $id, 'hashtag' => $tag]);
 860                                 return true;
 861                         }
 862                 }
 863
 864                 Logger::info('No matching hashtags found - rejected', ['id' => $id]);
 865                 return false;
 866         }
 867
 868         /**
 869          * perform a "follow" request
 870          *
 871          * @param array $activity
 872          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 873          * @throws \ImagickException
 874          */
 875         public static function followUser($activity)
 876         {
 877                 $uid = User::getIdForURL($activity['object_id']);
 878                 if (empty($uid)) {
 879                         return;
 880                 }
 881
 882                 $owner = User::getOwnerDataById($uid);
 883                 if (empty($owner)) {
 884                         return;
 885                 }
 886
 887                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 888                 if (!empty($cid)) {
 889                         self::switchContact($cid);
 890                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 891                         $contact = DBA::selectFirst('contact', [], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 892                 } else {
 893                         $contact = [];
 894                 }
 895
 896                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 897                         'author-link' => $activity['actor']];
 898
 899                 $note = Strings::escapeTags(trim($activity['content'] ?? ''));
 900
 901                 // Ensure that the contact has got the right network type
 902                 self::switchContact($item['author-id']);
 903
 904                 $result = Contact::addRelationship($owner, $contact, $item, false, $note);
 905                 if ($result === true) {
 906                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
 907                 }
 908
 909                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 910                 if (empty($cid)) {
 911                         return;
 912                 }
 913
 914                 if (empty($contact)) {
 915                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 916                 }
 917
 918                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 919         }
 920
 921         /**
 922          * Update the given profile
 923          *
 924          * @param array $activity
 925          * @throws \Exception
 926          */
 927         public static function updatePerson($activity)
 928         {
 929                 if (empty($activity['object_id'])) {
 930                         return;
 931                 }
 932
 933                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
 934                 Contact::updateFromProbeByURL($activity['object_id']);
 935         }
 936
 937         /**
 938          * Delete the given profile
 939          *
 940          * @param array $activity
 941          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 942          */
 943         public static function deletePerson($activity)
 944         {
 945                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 946                         Logger::info('Empty object id or actor.');
 947                         return;
 948                 }
 949
 950                 if ($activity['object_id'] != $activity['actor']) {
 951                         Logger::info('Object id does not match actor.');
 952                         return;
 953                 }
 954
 955                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 956                 while ($contact = DBA::fetch($contacts)) {
 957                         Contact::remove($contact['id']);
 958                 }
 959                 DBA::close($contacts);
 960
 961                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
 962         }
 963
 964         /**
 965          * Accept a follow request
 966          *
 967          * @param array $activity
 968          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 969          * @throws \ImagickException
 970          */
 971         public static function acceptFollowUser($activity)
 972         {
 973                 $uid = User::getIdForURL($activity['object_actor']);
 974                 if (empty($uid)) {
 975                         return;
 976                 }
 977
 978                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 979                 if (empty($cid)) {
 980                         Logger::info('No contact found', ['actor' => $activity['actor']]);
 981                         return;
 982                 }
 983
 984                 self::switchContact($cid);
 985
 986                 $fields = ['pending' => false];
 987
 988                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
 989                 if ($contact['rel'] == Contact::FOLLOWER) {
 990                         $fields['rel'] = Contact::FRIEND;
 991                 }
 992
 993                 $condition = ['id' => $cid];
 994                 DBA::update('contact', $fields, $condition);
 995                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
 996         }
 997
 998         /**
 999          * Reject a follow request
1000          *
1001          * @param array $activity
1002          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1003          * @throws \ImagickException
1004          */
1005         public static function rejectFollowUser($activity)
1006         {
1007                 $uid = User::getIdForURL($activity['object_actor']);
1008                 if (empty($uid)) {
1009                         return;
1010                 }
1011
1012                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1013                 if (empty($cid)) {
1014                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1015                         return;
1016                 }
1017
1018                 self::switchContact($cid);
1019
1020                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
1021                         Contact::remove($cid);
1022                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1023                 } else {
1024                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1025                 }
1026         }
1027
1028         /**
1029          * Undo activity like "like" or "dislike"
1030          *
1031          * @param array $activity
1032          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1033          * @throws \ImagickException
1034          */
1035         public static function undoActivity($activity)
1036         {
1037                 if (empty($activity['object_id'])) {
1038                         return;
1039                 }
1040
1041                 if (empty($activity['object_actor'])) {
1042                         return;
1043                 }
1044
1045                 $author_id = Contact::getIdForURL($activity['object_actor']);
1046                 if (empty($author_id)) {
1047                         return;
1048                 }
1049
1050                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1051         }
1052
1053         /**
1054          * Activity to remove a follower
1055          *
1056          * @param array $activity
1057          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1058          * @throws \ImagickException
1059          */
1060         public static function undoFollowUser($activity)
1061         {
1062                 $uid = User::getIdForURL($activity['object_object']);
1063                 if (empty($uid)) {
1064                         return;
1065                 }
1066
1067                 $owner = User::getOwnerDataById($uid);
1068                 if (empty($owner)) {
1069                         return;
1070                 }
1071
1072                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1073                 if (empty($cid)) {
1074                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1075                         return;
1076                 }
1077
1078                 self::switchContact($cid);
1079
1080                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1081                 if (!DBA::isResult($contact)) {
1082                         return;
1083                 }
1084
1085                 Contact::removeFollower($owner, $contact);
1086                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1087         }
1088
1089         /**
1090          * Switches a contact to AP if needed
1091          *
1092          * @param integer $cid Contact ID
1093          * @throws \Exception
1094          */
1095         private static function switchContact($cid)
1096         {
1097                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1098                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1099                         return;
1100                 }
1101
1102                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1103                 Contact::updateFromProbe($cid);
1104         }
1105
1106         /**
1107          * Collects implicit mentions like:
1108          * - the author of the parent item
1109          * - all the mentioned conversants in the parent item
1110          *
1111          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1112          * @return array
1113          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1114          */
1115         private static function getImplicitMentionList(array $parent)
1116         {
1117                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1118
1119                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1120
1121                 $implicit_mentions = [];
1122                 if (empty($parent_author['url'])) {
1123                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
1124                 } else {
1125                         $implicit_mentions[] = $parent_author['url'];
1126                         $implicit_mentions[] = $parent_author['nurl'];
1127                         $implicit_mentions[] = $parent_author['alias'];
1128                 }
1129
1130                 if (!empty($parent['alias'])) {
1131                         $implicit_mentions[] = $parent['alias'];
1132                 }
1133
1134                 foreach ($parent_terms as $term) {
1135                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1136                         if (!empty($contact['url'])) {
1137                                 $implicit_mentions[] = $contact['url'];
1138                                 $implicit_mentions[] = $contact['nurl'];
1139                                 $implicit_mentions[] = $contact['alias'];
1140                         }
1141                 }
1142
1143                 return $implicit_mentions;
1144         }
1145
1146         /**
1147          * Strips from the body prepended implicit mentions
1148          *
1149          * @param string $body
1150          * @param array $parent
1151          * @return string
1152          */
1153         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1154         {
1155                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1156                         return $body;
1157                 }
1158
1159                 $potential_mentions = self::getImplicitMentionList($parent);
1160
1161                 $kept_mentions = [];
1162
1163                 // Extract one prepended mention at a time from the body
1164                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1165                         if (!in_array($matches[2], $potential_mentions)) {
1166                                 $kept_mentions[] = $matches[1];
1167                         }
1168
1169                         $body = $matches[3];
1170                 }
1171
1172                 // Re-appending the kept mentions to the body after extraction
1173                 $kept_mentions[] = $body;
1174
1175                 return implode('', $kept_mentions);
1176         }
1177 }