src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol\ActivityPub;
  23
  24 use Friendica\Content\PageInfo;
  25 use Friendica\Content\Text\BBCode;
  26 use Friendica\Content\Text\HTML;
  27 use Friendica\Core\Logger;
  28 use Friendica\Core\Protocol;
  29 use Friendica\Database\DBA;
  30 use Friendica\DI;
  31 use Friendica\Model\APContact;
  32 use Friendica\Model\Contact;
  33 use Friendica\Model\Conversation;
  34 use Friendica\Model\Event;
  35 use Friendica\Model\Item;
  36 use Friendica\Model\ItemURI;
  37 use Friendica\Model\Mail;
  38 use Friendica\Model\Tag;
  39 use Friendica\Model\User;
  40 use Friendica\Protocol\Activity;
  41 use Friendica\Protocol\ActivityPub;
  42 use Friendica\Util\DateTimeFormat;
  43 use Friendica\Util\JsonLD;
  44 use Friendica\Util\Strings;
  45
  46 /**
  47  * ActivityPub Processor Protocol class
  48  */
  49 class Processor
  50 {
  51         /**
  52          * Converts mentions from Pleroma into the Friendica format
  53          *
  54          * @param string $body
  55          *
  56          * @return string converted body
  57          */
  58         private static function convertMentions($body)
  59         {
  60                 $URLSearchString = "^\[\]";
  61                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
  62
  63                 return $body;
  64         }
  65
  66         /**
  67          * Replaces emojis in the body
  68          *
  69          * @param array $emojis
  70          * @param string $body
  71          *
  72          * @return string with replaced emojis
  73          */
  74         private static function replaceEmojis($body, array $emojis)
  75         {
  76                 foreach ($emojis as $emoji) {
  77                         $replace = '[class=emoji mastodon][img=' . $emoji['href'] . ']' . $emoji['name'] . '[/img][/class]';
  78                         $body = str_replace($emoji['name'], $replace, $body);
  79                 }
  80                 return $body;
  81         }
  82
  83         /**
  84          * Add attachment data to the item array
  85          *
  86          * @param array   $activity
  87          * @param array   $item
  88          *
  89          * @return array array
  90          */
  91         private static function constructAttachList($activity, $item)
  92         {
  93                 if (empty($activity['attachments'])) {
  94                         return $item;
  95                 }
  96
  97                 foreach ($activity['attachments'] as $attach) {
  98                         switch ($attach['type']) {
  99                                 case 'link':
 100                                         $data = [
 101                                                 'url'      => $attach['url'],
 102                                                 'type'     => $attach['type'],
 103                                                 'title'    => $attach['title'] ?? '',
 104                                                 'text'     => $attach['desc']  ?? '',
 105                                                 'image'    => $attach['image'] ?? '',
 106                                                 'images'   => [],
 107                                                 'keywords' => [],
 108                                         ];
 109                                         $item['body'] = PageInfo::appendDataToBody($item['body'], $data);
 110                                         break;
 111                                 default:
 112                                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 113                                         if ($filetype == 'image') {
 114                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 115                                                         continue 2;
 116                                                 }
 117
 118                                                 $item['body'] .= "\n";
 119
 120                                                 // image is the preview/thumbnail URL
 121                                                 if (!empty($attach['image'])) {
 122                                                         $item['body'] .= '[url=' . $attach['url'] . ']';
 123                                                         $attach['url'] = $attach['image'];
 124                                                 }
 125
 126                                                 if (empty($attach['name'])) {
 127                                                         $item['body'] .= '[img]' . $attach['url'] . '[/img]';
 128                                                 } else {
 129                                                         $item['body'] .= '[img=' . $attach['url'] . ']' . $attach['name'] . '[/img]';
 130                                                 }
 131
 132                                                 if (!empty($attach['image'])) {
 133                                                         $item['body'] .= '[/url]';
 134                                                 }
 135                                         } elseif ($filetype == 'audio') {
 136                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 137                                                         continue 2;
 138                                                 }
 139
 140                                                 $item['body'] .= "\n[audio]" . $attach['url'] . '[/audio]';
 141                                         } elseif ($filetype == 'video') {
 142                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 143                                                         continue 2;
 144                                                 }
 145
 146                                                 $item['body'] .= "\n[video]" . $attach['url'] . '[/video]';
 147                                         } else {
 148                                                 if (!empty($item["attach"])) {
 149                                                         $item["attach"] .= ',';
 150                                                 } else {
 151                                                         $item["attach"] = '';
 152                                                 }
 153
 154                                                 $item["attach"] .= '[attach]href="' . $attach['url'] . '" length="' . ($attach['length'] ?? '0') . '" type="' . $attach['mediaType'] . '" title="' . ($attach['name'] ?? '') . '"[/attach]';
 155                                         }
 156                         }
 157                 }
 158
 159                 return $item;
 160         }
 161
 162         /**
 163          * Updates a message
 164          *
 165          * @param array $activity Activity array
 166          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 167          */
 168         public static function updateItem($activity)
 169         {
 170                 $item = Item::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity'], ['uri' => $activity['id']]);
 171                 if (!DBA::isResult($item)) {
 172                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 173                         $item = self::createItem($activity);
 174                         self::postItem($activity, $item);
 175                         return;
 176                 }
 177
 178                 $item['changed'] = DateTimeFormat::utcNow();
 179                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 180
 181                 $item = self::processContent($activity, $item);
 182                 if (empty($item)) {
 183                         return;
 184                 }
 185
 186                 Item::update($item, ['uri' => $activity['id']]);
 187         }
 188
 189         /**
 190          * Prepares data for a message
 191          *
 192          * @param array $activity Activity array
 193          * @return array Internal item
 194          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 195          * @throws \ImagickException
 196          */
 197         public static function createItem($activity)
 198         {
 199                 $item = [];
 200                 $item['verb'] = Activity::POST;
 201                 $item['thr-parent'] = $activity['reply-to-id'];
 202
 203                 if ($activity['reply-to-id'] == $activity['id']) {
 204                         $item['gravity'] = GRAVITY_PARENT;
 205                         $item['object-type'] = Activity\ObjectType::NOTE;
 206                 } else {
 207                         $item['gravity'] = GRAVITY_COMMENT;
 208                         $item['object-type'] = Activity\ObjectType::COMMENT;
 209
 210                         // Ensure that the comment reaches all receivers of the referring post
 211                         $activity['receiver'] = self::addReceivers($activity);
 212                 }
 213
 214                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Item::exists(['uri' => $activity['reply-to-id']])) {
 215                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 216                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 217                 }
 218
 219                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 220
 221                 /// @todo What to do with $activity['context']?
 222                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['thr-parent']])) {
 223                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 224                         return [];
 225                 }
 226
 227                 $item['network'] = Protocol::ACTIVITYPUB;
 228                 $item['author-link'] = $activity['author'];
 229                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 230                 $item['owner-link'] = $activity['actor'];
 231                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 232
 233                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 234                         $item['private'] = Item::UNLISTED;
 235                 } elseif (in_array(0, $activity['receiver'])) {
 236                         $item['private'] = Item::PUBLIC;
 237                 } else {
 238                         $item['private'] = Item::PRIVATE;
 239                 }
 240
 241                 if (!empty($activity['raw'])) {
 242                         $item['source'] = $activity['raw'];
 243                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 244                         $item['conversation-href'] = $activity['context'] ?? '';
 245                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 246
 247                         if (isset($activity['push'])) {
 248                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 249                         }
 250                 }
 251
 252                 $item['isForum'] = false;
 253
 254                 if (!empty($activity['thread-completion'])) {
 255                         // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 256                         $item['causer-link'] = $item['owner-link'];
 257                         $item['causer-id'] = $item['owner-id'];
 258
 259                         Logger::info('Ignoring actor because of thread completion.', ['actor' => $item['owner-link']]);
 260                         $item['owner-link'] = $item['author-link'];
 261                         $item['owner-id'] = $item['author-id'];
 262                 } else {
 263                         $actor = APContact::getByURL($item['owner-link'], false);
 264                         $item['isForum'] = ($actor['type'] == 'Group');
 265                 }
 266
 267                 $item['uri'] = $activity['id'];
 268
 269                 $item['created'] = DateTimeFormat::utc($activity['published']);
 270                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 271                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 272                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 273
 274                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 275
 276                 $item = self::processContent($activity, $item);
 277                 if (empty($item)) {
 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          * Add users to the receiver list of the given public activity.
 335          * This is used to ensure that the activity will be stored in every thread.
 336          *
 337          * @param array $activity Activity array
 338          * @return array Modified receiver list
 339          */
 340         private static function addReceivers(array $activity)
 341         {
 342                 if (!in_array(0, $activity['receiver'])) {
 343                         // Private activities will not be modified
 344                         return $activity['receiver'];
 345                 }
 346
 347                 // Add all owners of the referring item to the receivers
 348                 $original = $receivers = $activity['receiver'];
 349                 $items = Item::select(['uid'], ['uri' => $activity['object_id']]);
 350                 while ($item = DBA::fetch($items)) {
 351                         $receivers['uid:' . $item['uid']] = $item['uid'];
 352                 }
 353                 DBA::close($items);
 354
 355                 if (count($original) != count($receivers)) {
 356                         Logger::info('Improved data', ['id' => $activity['id'], 'object' => $activity['object_id'], 'original' => $original, 'improved' => $receivers]);
 357                 }
 358
 359                 return $receivers;
 360         }
 361
 362         /**
 363          * Prepare the item array for an activity
 364          *
 365          * @param array  $activity Activity array
 366          * @param string $verb     Activity verb
 367          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 368          * @throws \ImagickException
 369          */
 370         public static function createActivity($activity, $verb)
 371         {
 372                 $item = self::createItem($activity);
 373                 $item['verb'] = $verb;
 374                 $item['thr-parent'] = $activity['object_id'];
 375                 $item['gravity'] = GRAVITY_ACTIVITY;
 376                 $item['object-type'] = Activity\ObjectType::NOTE;
 377
 378                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 379
 380                 $activity['receiver'] = self::addReceivers($activity);
 381
 382                 self::postItem($activity, $item);
 383         }
 384
 385         /**
 386          * Create an event
 387          *
 388          * @param array $activity Activity array
 389          * @param array $item
 390          * @throws \Exception
 391          */
 392         public static function createEvent($activity, $item)
 393         {
 394                 $event['summary']  = HTML::toBBCode($activity['name']);
 395                 $event['desc']     = HTML::toBBCode($activity['content']);
 396                 $event['start']    = $activity['start-time'];
 397                 $event['finish']   = $activity['end-time'];
 398                 $event['nofinish'] = empty($event['finish']);
 399                 $event['location'] = $activity['location'];
 400                 $event['adjust']   = true;
 401                 $event['cid']      = $item['contact-id'];
 402                 $event['uid']      = $item['uid'];
 403                 $event['uri']      = $item['uri'];
 404                 $event['edited']   = $item['edited'];
 405                 $event['private']  = $item['private'];
 406                 $event['guid']     = $item['guid'];
 407                 $event['plink']    = $item['plink'];
 408
 409                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 410                 $ev = DBA::selectFirst('event', ['id'], $condition);
 411                 if (DBA::isResult($ev)) {
 412                         $event['id'] = $ev['id'];
 413                 }
 414
 415                 $event_id = Event::store($event);
 416                 Logger::info('Event was stored', ['id' => $event_id]);
 417         }
 418
 419         /**
 420          * Process the content
 421          *
 422          * @param array $activity Activity array
 423          * @param array $item
 424          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 425          * @throws \Exception
 426          */
 427         private static function processContent($activity, $item)
 428         {
 429                 $item['title'] = HTML::toBBCode($activity['name']);
 430
 431                 if (!empty($activity['source'])) {
 432                         $item['body'] = $activity['source'];
 433                 } else {
 434                         $content = HTML::toBBCode($activity['content']);
 435
 436                         if (!empty($activity['emojis'])) {
 437                                 $content = self::replaceEmojis($content, $activity['emojis']);
 438                         }
 439
 440                         $content = self::convertMentions($content);
 441
 442                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 443                                 $item_private = !in_array(0, $activity['item_receiver']);
 444                                 $parent = Item::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 445                                 if (!DBA::isResult($parent)) {
 446                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 447                                         return false;
 448                                 }
 449                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 450                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 451                                         return false;
 452                                 }
 453
 454                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 455                         }
 456                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 457                         $item['body'] = $content;
 458                 }
 459
 460                 self::storeFromBody($item);
 461                 self::storeTags($item['uri-id'], $activity['tags']);
 462
 463                 $item['location'] = $activity['location'];
 464
 465                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 466                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 467                 }
 468
 469                 $item['app'] = $activity['generator'];
 470
 471                 return $item;
 472         }
 473
 474         /**
 475          * Store hashtags and mentions
 476          *
 477          * @param array $item
 478          */
 479         private static function storeFromBody(array $item)
 480         {
 481                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 482                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 483
 484                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 485         }
 486
 487         /**
 488          * Generate a GUID out of an URL
 489          *
 490          * @param string $url message URL
 491          * @return string with GUID
 492          */
 493         private static function getGUIDByURL(string $url)
 494         {
 495                 $parsed = parse_url($url);
 496
 497                 $host_hash = hash('crc32', $parsed['host']);
 498
 499                 unset($parsed["scheme"]);
 500                 unset($parsed["host"]);
 501
 502                 $path = implode("/", $parsed);
 503
 504                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 505         }
 506
 507         /**
 508          * Creates an item post
 509          *
 510          * @param array $activity Activity data
 511          * @param array $item     item array
 512          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 513          * @throws \ImagickException
 514          */
 515         public static function postItem(array $activity, array $item)
 516         {
 517                 if (empty($item)) {
 518                         return;
 519                 }
 520
 521                 $stored = false;
 522
 523                 foreach ($activity['receiver'] as $receiver) {
 524                         if ($receiver == -1) {
 525                                 continue;
 526                         }
 527
 528                         $item['uid'] = $receiver;
 529
 530                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 531                         switch($type) {
 532                                 case Receiver::TARGET_TO:
 533                                         $item['post-type'] = Item::PT_TO;
 534                                         break;
 535                                 case Receiver::TARGET_CC:
 536                                         $item['post-type'] = Item::PT_CC;
 537                                         break;
 538                                 case Receiver::TARGET_BTO:
 539                                         $item['post-type'] = Item::PT_BTO;
 540                                         break;
 541                                 case Receiver::TARGET_BCC:
 542                                         $item['post-type'] = Item::PT_BCC;
 543                                         break;
 544                                 case Receiver::TARGET_FOLLOWER:
 545                                         $item['post-type'] = Item::PT_FOLLOWER;
 546                                         break;
 547                                 default:
 548                                         $item['post-type'] = Item::PT_ARTICLE;
 549                         }
 550
 551                         if ($item['isForum'] ?? false) {
 552                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 553                         } else {
 554                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 555                         }
 556
 557                         if (($receiver != 0) && empty($item['contact-id'])) {
 558                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 559                         }
 560
 561                         if (!empty($activity['directmessage'])) {
 562                                 self::postMail($activity, $item);
 563                                 continue;
 564                         }
 565
 566                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 567                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 568
 569                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 570                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 571                                 }
 572
 573                                 if ($skip) {
 574                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 575                                         continue;
 576                                 }
 577
 578                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 579                         }
 580
 581                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 582                                 self::createEvent($activity, $item);
 583                         }
 584
 585                         $item_id = Item::insert($item);
 586                         if ($item_id) {
 587                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 588                         } else {
 589                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 590                         }
 591
 592                         if ($item['uid'] == 0) {
 593                                 $stored = $item_id;
 594                         }
 595                 }
 596
 597                 // Store send a follow request for every reshare - but only when the item had been stored
 598                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 599                         $author = APContact::getByURL($item['owner-link'], false);
 600                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 601                         if ($author['type'] != 'Group') {
 602                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 603                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 604                         }
 605                 }
 606         }
 607
 608         /**
 609          * Store tags and mentions into the tag table
 610          *
 611          * @param integer $uriid
 612          * @param array $tags
 613          */
 614         private static function storeTags(int $uriid, array $tags = null)
 615         {
 616                 foreach ($tags as $tag) {
 617                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 618                                 continue;
 619                         }
 620
 621                         $hash = substr($tag['name'], 0, 1);
 622
 623                         if ($tag['type'] == 'Mention') {
 624                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 625                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 626                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 627                                         $tag['name'] = substr($tag['name'], 1);
 628                                 }
 629                                 $type = Tag::IMPLICIT_MENTION;
 630
 631                                 if (!empty($tag['href'])) {
 632                                         $apcontact = APContact::getByURL($tag['href']);
 633                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 634                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 635                                         }
 636                                 }
 637                         } elseif ($tag['type'] == 'Hashtag') {
 638                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 639                                         $tag['name'] = substr($tag['name'], 1);
 640                                 }
 641                                 $type = Tag::HASHTAG;
 642                         }
 643
 644                         if (empty($tag['name'])) {
 645                                 continue;
 646                         }
 647
 648                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 649                 }
 650         }
 651
 652         /**
 653          * Creates an mail post
 654          *
 655          * @param array $activity Activity data
 656          * @param array $item     item array
 657          * @return int|bool New mail table row id or false on error
 658          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 659          */
 660         private static function postMail($activity, $item)
 661         {
 662                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 663                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 664                         return false;
 665                 }
 666
 667                 Logger::info('Direct Message', $item);
 668
 669                 $msg = [];
 670                 $msg['uid'] = $item['uid'];
 671
 672                 $msg['contact-id'] = $item['contact-id'];
 673
 674                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 675                 $msg['from-name'] = $contact['name'];
 676                 $msg['from-url'] = $contact['url'];
 677                 $msg['from-photo'] = $contact['photo'];
 678
 679                 $msg['uri'] = $item['uri'];
 680                 $msg['created'] = $item['created'];
 681
 682                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 683                 if (DBA::isResult($parent)) {
 684                         $msg['parent-uri'] = $parent['parent-uri'];
 685                         $msg['title'] = $parent['title'];
 686                 } else {
 687                         $msg['parent-uri'] = $item['thr-parent'];
 688
 689                         if (!empty($item['title'])) {
 690                                 $msg['title'] = $item['title'];
 691                         } elseif (!empty($item['content-warning'])) {
 692                                 $msg['title'] = $item['content-warning'];
 693                         } else {
 694                                 // Trying to generate a title out of the body
 695                                 $title = $item['body'];
 696
 697                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 698                                         $title = $matches[3];
 699                                 }
 700
 701                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, BBCode::API, true), 0));
 702
 703                                 if (strlen($title) > 20) {
 704                                         $title = substr($title, 0, 20) . '...';
 705                                 }
 706
 707                                 $msg['title'] = $title;
 708                         }
 709                 }
 710                 $msg['body'] = $item['body'];
 711
 712                 return Mail::insert($msg);
 713         }
 714
 715         /**
 716          * Fetches missing posts
 717          *
 718          * @param string $url message URL
 719          * @param array $child activity array with the child of this message
 720          * @return string fetched message URL
 721          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 722          */
 723         public static function fetchMissingActivity(string $url, array $child = [])
 724         {
 725                 if (!empty($child['receiver'])) {
 726                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 727                 } else {
 728                         $uid = 0;
 729                 }
 730
 731                 $object = ActivityPub::fetchContent($url, $uid);
 732                 if (empty($object)) {
 733                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 734                         return '';
 735                 }
 736
 737                 if (empty($object['id'])) {
 738                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 739                         return '';
 740                 }
 741
 742                 if (!empty($child['author'])) {
 743                         $actor = $child['author'];
 744                 } elseif (!empty($object['actor'])) {
 745                         $actor = $object['actor'];
 746                 } elseif (!empty($object['attributedTo'])) {
 747                         $actor = $object['attributedTo'];
 748                 } else {
 749                         // Shouldn't happen
 750                         $actor = '';
 751                 }
 752
 753                 if (!empty($object['published'])) {
 754                         $published = $object['published'];
 755                 } elseif (!empty($child['published'])) {
 756                         $published = $child['published'];
 757                 } else {
 758                         $published = DateTimeFormat::utcNow();
 759                 }
 760
 761                 $activity = [];
 762                 $activity['@context'] = $object['@context'];
 763                 unset($object['@context']);
 764                 $activity['id'] = $object['id'];
 765                 $activity['to'] = $object['to'] ?? [];
 766                 $activity['cc'] = $object['cc'] ?? [];
 767                 $activity['actor'] = $actor;
 768                 $activity['object'] = $object;
 769                 $activity['published'] = $published;
 770                 $activity['type'] = 'Create';
 771
 772                 $ldactivity = JsonLD::compact($activity);
 773
 774                 $ldactivity['thread-completion'] = true;
 775
 776                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity));
 777
 778                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 779
 780                 return $activity['id'];
 781         }
 782
 783         /**
 784          * perform a "follow" request
 785          *
 786          * @param array $activity
 787          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 788          * @throws \ImagickException
 789          */
 790         public static function followUser($activity)
 791         {
 792                 $uid = User::getIdForURL($activity['object_id']);
 793                 if (empty($uid)) {
 794                         return;
 795                 }
 796
 797                 $owner = User::getOwnerDataById($uid);
 798                 if (empty($owner)) {
 799                         return;
 800                 }
 801
 802                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 803                 if (!empty($cid)) {
 804                         self::switchContact($cid);
 805                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 806                         $contact = DBA::selectFirst('contact', [], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 807                 } else {
 808                         $contact = [];
 809                 }
 810
 811                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 812                         'author-link' => $activity['actor']];
 813
 814                 $note = Strings::escapeTags(trim($activity['content'] ?? ''));
 815
 816                 // Ensure that the contact has got the right network type
 817                 self::switchContact($item['author-id']);
 818
 819                 $result = Contact::addRelationship($owner, $contact, $item, false, $note);
 820                 if ($result === true) {
 821                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
 822                 }
 823
 824                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 825                 if (empty($cid)) {
 826                         return;
 827                 }
 828
 829                 if (empty($contact)) {
 830                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 831                 }
 832
 833                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 834         }
 835
 836         /**
 837          * Update the given profile
 838          *
 839          * @param array $activity
 840          * @throws \Exception
 841          */
 842         public static function updatePerson($activity)
 843         {
 844                 if (empty($activity['object_id'])) {
 845                         return;
 846                 }
 847
 848                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
 849                 Contact::updateFromProbeByURL($activity['object_id']);
 850         }
 851
 852         /**
 853          * Delete the given profile
 854          *
 855          * @param array $activity
 856          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 857          */
 858         public static function deletePerson($activity)
 859         {
 860                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 861                         Logger::info('Empty object id or actor.');
 862                         return;
 863                 }
 864
 865                 if ($activity['object_id'] != $activity['actor']) {
 866                         Logger::info('Object id does not match actor.');
 867                         return;
 868                 }
 869
 870                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 871                 while ($contact = DBA::fetch($contacts)) {
 872                         Contact::remove($contact['id']);
 873                 }
 874                 DBA::close($contacts);
 875
 876                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
 877         }
 878
 879         /**
 880          * Accept a follow request
 881          *
 882          * @param array $activity
 883          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 884          * @throws \ImagickException
 885          */
 886         public static function acceptFollowUser($activity)
 887         {
 888                 $uid = User::getIdForURL($activity['object_actor']);
 889                 if (empty($uid)) {
 890                         return;
 891                 }
 892
 893                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 894                 if (empty($cid)) {
 895                         Logger::info('No contact found', ['actor' => $activity['actor']]);
 896                         return;
 897                 }
 898
 899                 self::switchContact($cid);
 900
 901                 $fields = ['pending' => false];
 902
 903                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
 904                 if ($contact['rel'] == Contact::FOLLOWER) {
 905                         $fields['rel'] = Contact::FRIEND;
 906                 }
 907
 908                 $condition = ['id' => $cid];
 909                 DBA::update('contact', $fields, $condition);
 910                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
 911         }
 912
 913         /**
 914          * Reject a follow request
 915          *
 916          * @param array $activity
 917          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 918          * @throws \ImagickException
 919          */
 920         public static function rejectFollowUser($activity)
 921         {
 922                 $uid = User::getIdForURL($activity['object_actor']);
 923                 if (empty($uid)) {
 924                         return;
 925                 }
 926
 927                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 928                 if (empty($cid)) {
 929                         Logger::info('No contact found', ['actor' => $activity['actor']]);
 930                         return;
 931                 }
 932
 933                 self::switchContact($cid);
 934
 935                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
 936                         Contact::remove($cid);
 937                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
 938                 } else {
 939                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
 940                 }
 941         }
 942
 943         /**
 944          * Undo activity like "like" or "dislike"
 945          *
 946          * @param array $activity
 947          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 948          * @throws \ImagickException
 949          */
 950         public static function undoActivity($activity)
 951         {
 952                 if (empty($activity['object_id'])) {
 953                         return;
 954                 }
 955
 956                 if (empty($activity['object_actor'])) {
 957                         return;
 958                 }
 959
 960                 $author_id = Contact::getIdForURL($activity['object_actor']);
 961                 if (empty($author_id)) {
 962                         return;
 963                 }
 964
 965                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
 966         }
 967
 968         /**
 969          * Activity to remove a follower
 970          *
 971          * @param array $activity
 972          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 973          * @throws \ImagickException
 974          */
 975         public static function undoFollowUser($activity)
 976         {
 977                 $uid = User::getIdForURL($activity['object_object']);
 978                 if (empty($uid)) {
 979                         return;
 980                 }
 981
 982                 $owner = User::getOwnerDataById($uid);
 983                 if (empty($owner)) {
 984                         return;
 985                 }
 986
 987                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 988                 if (empty($cid)) {
 989                         Logger::info('No contact found', ['actor' => $activity['actor']]);
 990                         return;
 991                 }
 992
 993                 self::switchContact($cid);
 994
 995                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
 996                 if (!DBA::isResult($contact)) {
 997                         return;
 998                 }
 999
1000                 Contact::removeFollower($owner, $contact);
1001                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1002         }
1003
1004         /**
1005          * Switches a contact to AP if needed
1006          *
1007          * @param integer $cid Contact ID
1008          * @throws \Exception
1009          */
1010         private static function switchContact($cid)
1011         {
1012                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1013                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1014                         return;
1015                 }
1016
1017                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1018                 Contact::updateFromProbe($cid);
1019         }
1020
1021         /**
1022          * Collects implicit mentions like:
1023          * - the author of the parent item
1024          * - all the mentioned conversants in the parent item
1025          *
1026          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1027          * @return array
1028          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1029          */
1030         private static function getImplicitMentionList(array $parent)
1031         {
1032                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1033
1034                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1035
1036                 $implicit_mentions = [];
1037                 if (empty($parent_author['url'])) {
1038                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
1039                 } else {
1040                         $implicit_mentions[] = $parent_author['url'];
1041                         $implicit_mentions[] = $parent_author['nurl'];
1042                         $implicit_mentions[] = $parent_author['alias'];
1043                 }
1044
1045                 if (!empty($parent['alias'])) {
1046                         $implicit_mentions[] = $parent['alias'];
1047                 }
1048
1049                 foreach ($parent_terms as $term) {
1050                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1051                         if (!empty($contact['url'])) {
1052                                 $implicit_mentions[] = $contact['url'];
1053                                 $implicit_mentions[] = $contact['nurl'];
1054                                 $implicit_mentions[] = $contact['alias'];
1055                         }
1056                 }
1057
1058                 return $implicit_mentions;
1059         }
1060
1061         /**
1062          * Strips from the body prepended implicit mentions
1063          *
1064          * @param string $body
1065          * @param array $parent
1066          * @return string
1067          */
1068         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1069         {
1070                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1071                         return $body;
1072                 }
1073
1074                 $potential_mentions = self::getImplicitMentionList($parent);
1075
1076                 $kept_mentions = [];
1077
1078                 // Extract one prepended mention at a time from the body
1079                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1080                         if (!in_array($matches[2], $potential_mentions)) {
1081                                 $kept_mentions[] = $matches[1];
1082                         }
1083
1084                         $body = $matches[3];
1085                 }
1086
1087                 // Re-appending the kept mentions to the body after extraction
1088                 $kept_mentions[] = $body;
1089
1090                 return implode('', $kept_mentions);
1091         }
1092 }