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