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\Term;
  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          * Constructs a string with tags for a given tag array
  84          *
  85          * @param array   $tags
  86          * @param boolean $sensitive
  87          * @return string with tags
  88          */
  89         private static function constructTagString(array $tags = null, $sensitive = false)
  90         {
  91                 if (empty($tags)) {
  92                         return '';
  93                 }
  94
  95                 $tag_text = '';
  96                 foreach ($tags as $tag) {
  97                         if (in_array($tag['type'] ?? '', ['Mention', 'Hashtag'])) {
  98                                 if (!empty($tag_text)) {
  99                                         $tag_text .= ',';
 100                                 }
 101
 102                                 $tag_text .= substr($tag['name'], 0, 1) . '[url=' . $tag['href'] . ']' . substr($tag['name'], 1) . '[/url]';
 103                         }
 104                 }
 105
 106                 /// @todo add nsfw for $sensitive
 107
 108                 return $tag_text;
 109         }
 110
 111         /**
 112          * Add attachment data to the item array
 113          *
 114          * @param array   $activity
 115          * @param array   $item
 116          *
 117          * @return array array
 118          */
 119         private static function constructAttachList($activity, $item)
 120         {
 121                 if (empty($activity['attachments'])) {
 122                         return $item;
 123                 }
 124
 125                 foreach ($activity['attachments'] as $attach) {
 126                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 127                         if ($filetype == 'image') {
 128                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 129                                         continue;
 130                                 }
 131
 132                                 if (empty($attach['name'])) {
 133                                         $item['body'] .= "\n[img]" . $attach['url'] . '[/img]';
 134                                 } else {
 135                                         $item['body'] .= "\n[img=" . $attach['url'] . ']' . $attach['name'] . '[/img]';
 136                                 }
 137                         } elseif ($filetype == 'audio') {
 138                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 139                                         continue;
 140                                 }
 141
 142                                 $item['body'] .= "\n[audio]" . $attach['url'] . '[/audio]';
 143                         } elseif ($filetype == 'video') {
 144                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 145                                         continue;
 146                                 }
 147
 148                                 $item['body'] .= "\n[video]" . $attach['url'] . '[/video]';
 149                         } else {
 150                                 if (!empty($item["attach"])) {
 151                                         $item["attach"] .= ',';
 152                                 } else {
 153                                         $item["attach"] = '';
 154                                 }
 155                                 if (!isset($attach['length'])) {
 156                                         $attach['length'] = "0";
 157                                 }
 158                                 $item["attach"] .= '[attach]href="'.$attach['url'].'" length="'.$attach['length'].'" type="'.$attach['mediaType'].'" title="'.($attach['name'] ?? '') .'"[/attach]';
 159                         }
 160                 }
 161
 162                 return $item;
 163         }
 164
 165         /**
 166          * Updates a message
 167          *
 168          * @param array $activity Activity array
 169          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 170          */
 171         public static function updateItem($activity)
 172         {
 173                 $item = Item::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity'], ['uri' => $activity['id']]);
 174                 if (!DBA::isResult($item)) {
 175                         Logger::warning('Unknown item', ['uri' => $activity['id']]);
 176                         return;
 177                 }
 178
 179                 $item['changed'] = DateTimeFormat::utcNow();
 180                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 181
 182                 $item = self::processContent($activity, $item);
 183                 if (empty($item)) {
 184                         return;
 185                 }
 186
 187                 Item::update($item, ['uri' => $activity['id']]);
 188         }
 189
 190         /**
 191          * Prepares data for a message
 192          *
 193          * @param array $activity Activity array
 194          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 195          * @throws \ImagickException
 196          */
 197         public static function createItem($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'] = $activity['diaspora:comment'] ?? '';
 220
 221                 self::postItem($activity, $item);
 222         }
 223
 224         /**
 225          * Delete items
 226          *
 227          * @param array $activity
 228          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 229          * @throws \ImagickException
 230          */
 231         public static function deleteItem($activity)
 232         {
 233                 $owner = Contact::getIdForURL($activity['actor']);
 234
 235                 Logger::log('Deleting item ' . $activity['object_id'] . ' from ' . $owner, Logger::DEBUG);
 236                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 237         }
 238
 239         /**
 240          * Prepare the item array for an activity
 241          *
 242          * @param array $activity Activity array
 243          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 244          * @throws \ImagickException
 245          */
 246         public static function addTag($activity)
 247         {
 248                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 249                         return;
 250                 }
 251
 252                 foreach ($activity['receiver'] as $receiver) {
 253                         $item = Item::selectFirst(['id', 'tag', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 254                         if (!DBA::isResult($item)) {
 255                                 // We don't fetch missing content for this purpose
 256                                 continue;
 257                         }
 258
 259                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 260                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 261                                 continue;
 262                         }
 263
 264                         // To-Do:
 265                         // - Check if "blocktag" is set
 266                         // - Check if actor is a contact
 267
 268                         if (!stristr($item['tag'], trim($activity['object_content']))) {
 269                                 $tag = $item['tag'] . (strlen($item['tag']) ? ',' : '') . '#[url=' . $activity['object_id'] . ']'. $activity['object_content'] . '[/url]';
 270                                 Item::update(['tag' => $tag], ['id' => $item['id']]);
 271                                 Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 272                         }
 273                 }
 274         }
 275
 276         /**
 277          * Add users to the receiver list of the given public activity.
 278          * This is used to ensure that the activity will be stored in every thread.
 279          *
 280          * @param array $activity Activity array
 281          * @return array Modified receiver list
 282          */
 283         private static function addReceivers(array $activity)
 284         {
 285                 if (!in_array(0, $activity['receiver'])) {
 286                         // Private activities will not be modified
 287                         return $activity['receiver'];
 288                 }
 289
 290                 // Add all owners of the referring item to the receivers
 291                 $original = $receivers = $activity['receiver'];
 292                 $items = Item::select(['uid'], ['uri' => $activity['object_id']]);
 293                 while ($item = DBA::fetch($items)) {
 294                         $receivers['uid:' . $item['uid']] = $item['uid'];
 295                 }
 296                 DBA::close($items);
 297
 298                 if (count($original) != count($receivers)) {
 299                         Logger::info('Improved data', ['id' => $activity['id'], 'object' => $activity['object_id'], 'original' => $original, 'improved' => $receivers]);
 300                 }
 301
 302                 return $receivers;
 303         }
 304
 305         /**
 306          * Prepare the item array for an activity
 307          *
 308          * @param array  $activity Activity array
 309          * @param string $verb     Activity verb
 310          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 311          * @throws \ImagickException
 312          */
 313         public static function createActivity($activity, $verb)
 314         {
 315                 $item = [];
 316                 $item['verb'] = $verb;
 317                 $item['thr-parent'] = $activity['object_id'];
 318                 $item['gravity'] = GRAVITY_ACTIVITY;
 319                 $item['object-type'] = Activity\ObjectType::NOTE;
 320
 321                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 322
 323                 $activity['receiver'] = self::addReceivers($activity);
 324
 325                 self::postItem($activity, $item);
 326         }
 327
 328         /**
 329          * Create an event
 330          *
 331          * @param array $activity Activity array
 332          * @param array $item
 333          * @throws \Exception
 334          */
 335         public static function createEvent($activity, $item)
 336         {
 337                 $event['summary']  = HTML::toBBCode($activity['name']);
 338                 $event['desc']     = HTML::toBBCode($activity['content']);
 339                 $event['start']    = $activity['start-time'];
 340                 $event['finish']   = $activity['end-time'];
 341                 $event['nofinish'] = empty($event['finish']);
 342                 $event['location'] = $activity['location'];
 343                 $event['adjust']   = true;
 344                 $event['cid']      = $item['contact-id'];
 345                 $event['uid']      = $item['uid'];
 346                 $event['uri']      = $item['uri'];
 347                 $event['edited']   = $item['edited'];
 348                 $event['private']  = $item['private'];
 349                 $event['guid']     = $item['guid'];
 350                 $event['plink']    = $item['plink'];
 351
 352                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 353                 $ev = DBA::selectFirst('event', ['id'], $condition);
 354                 if (DBA::isResult($ev)) {
 355                         $event['id'] = $ev['id'];
 356                 }
 357
 358                 $event_id = Event::store($event);
 359                 Logger::log('Event '.$event_id.' was stored', Logger::DEBUG);
 360         }
 361
 362         /**
 363          * Process the content
 364          *
 365          * @param array $activity Activity array
 366          * @param array $item
 367          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 368          * @throws \Exception
 369          */
 370         private static function processContent($activity, $item)
 371         {
 372                 $item['title'] = HTML::toBBCode($activity['name']);
 373
 374                 if (!empty($activity['source'])) {
 375                         $item['body'] = $activity['source'];
 376                 } else {
 377                         $content = HTML::toBBCode($activity['content']);
 378
 379                         if (!empty($activity['emojis'])) {
 380                                 $content = self::replaceEmojis($content, $activity['emojis']);
 381                         }
 382
 383                         $content = self::convertMentions($content);
 384
 385                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 386                                 $item_private = !in_array(0, $activity['item_receiver']);
 387                                 $parent = Item::selectFirst(['id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 388                                 if (!DBA::isResult($parent)) {
 389                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 390                                         return false;
 391                                 }
 392                                 if ($item_private && ($parent['private'] == Item::PRIVATE)) {
 393                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 394                                         return false;
 395                                 }
 396
 397                                 $potential_implicit_mentions = self::getImplicitMentionList($parent);
 398                                 $content = self::removeImplicitMentionsFromBody($content, $potential_implicit_mentions);
 399                                 $activity['tags'] = self::convertImplicitMentionsInTags($activity['tags'], $potential_implicit_mentions);
 400                         }
 401                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 402                         $item['body'] = $content;
 403                 }
 404
 405                 $item['tag'] = self::constructTagString($activity['tags'], $activity['sensitive']);
 406
 407                 self::storeTags($item['uri-id'], $activity['tags']);
 408
 409                 $item['location'] = $activity['location'];
 410
 411                 if (!empty($item['latitude']) && !empty($item['longitude'])) {
 412                         $item['coord'] = $item['latitude'] . ' ' . $item['longitude'];
 413                 }
 414
 415                 $item['app'] = $activity['generator'];
 416
 417                 return $item;
 418         }
 419
 420         /**
 421          * Generate a GUID out of an URL
 422          *
 423          * @param string $url message URL
 424          * @return string with GUID
 425          */
 426         private static function getGUIDByURL(string $url)
 427         {
 428                 $parsed = parse_url($url);
 429
 430                 $host_hash = hash('crc32', $parsed['host']);
 431
 432                 unset($parsed["scheme"]);
 433                 unset($parsed["host"]);
 434
 435                 $path = implode("/", $parsed);
 436
 437                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 438         }
 439
 440         /**
 441          * Creates an item post
 442          *
 443          * @param array $activity Activity data
 444          * @param array $item     item array
 445          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 446          * @throws \ImagickException
 447          */
 448         private static function postItem($activity, $item)
 449         {
 450                 /// @todo What to do with $activity['context']?
 451                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['thr-parent']])) {
 452                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 453                         return;
 454                 }
 455
 456                 $item['network'] = Protocol::ACTIVITYPUB;
 457                 $item['author-link'] = $activity['author'];
 458                 $item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
 459                 $item['owner-link'] = $activity['actor'];
 460                 $item['owner-id'] = Contact::getIdForURL($activity['actor'], 0, true);
 461
 462                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 463                         $item['private'] = Item::UNLISTED;
 464                 } elseif (in_array(0, $activity['receiver'])) {
 465                         $item['private'] = Item::PUBLIC;
 466                 } else {
 467                         $item['private'] = Item::PRIVATE;
 468                 }
 469
 470                 if (!empty($activity['raw'])) {
 471                         $item['source'] = $activity['raw'];
 472                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 473                         $item['conversation-href'] = $activity['context'] ?? '';
 474                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 475
 476                         if (isset($activity['push'])) {
 477                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 478                         }
 479                 }
 480
 481                 $isForum = false;
 482
 483                 if (!empty($activity['thread-completion'])) {
 484                         // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 485                         $item['causer-link'] = $item['owner-link'];
 486                         $item['causer-id'] = $item['owner-id'];
 487
 488                         Logger::info('Ignoring actor because of thread completion.', ['actor' => $item['owner-link']]);
 489                         $item['owner-link'] = $item['author-link'];
 490                         $item['owner-id'] = $item['author-id'];
 491                 } else {
 492                         $actor = APContact::getByURL($item['owner-link'], false);
 493                         $isForum = ($actor['type'] == 'Group');
 494                 }
 495
 496                 $item['uri'] = $activity['id'];
 497
 498                 $item['created'] = DateTimeFormat::utc($activity['published']);
 499                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 500                 $item['guid'] = $activity['diaspora:guid'] ?: $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 501
 502                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 503
 504                 $item = self::processContent($activity, $item);
 505                 if (empty($item)) {
 506                         return;
 507                 }
 508
 509                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 510
 511                 $item = self::constructAttachList($activity, $item);
 512
 513                 $stored = false;
 514
 515                 foreach ($activity['receiver'] as $receiver) {
 516                         if ($receiver == -1) {
 517                                 continue;
 518                         }
 519
 520                         $item['uid'] = $receiver;
 521
 522                         if ($isForum) {
 523                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver, true);
 524                         } else {
 525                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
 526                         }
 527
 528                         if (($receiver != 0) && empty($item['contact-id'])) {
 529                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
 530                         }
 531
 532                         if (!empty($activity['directmessage'])) {
 533                                 self::postMail($activity, $item);
 534                                 continue;
 535                         }
 536
 537                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 538                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 539
 540                                 if ($skip && (($activity['type'] == 'as:Announce') || $isForum)) {
 541                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 542                                 }
 543
 544                                 if ($skip) {
 545                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 546                                         continue;
 547                                 }
 548
 549                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 550                         }
 551
 552                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 553                                 self::createEvent($activity, $item);
 554                         }
 555
 556                         $item_id = Item::insert($item);
 557                         if ($item_id) {
 558                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 559                         } else {
 560                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 561                         }
 562
 563                         if ($item['uid'] == 0) {
 564                                 $stored = $item_id;
 565                         }
 566                 }
 567
 568                 // Store send a follow request for every reshare - but only when the item had been stored
 569                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 570                         $author = APContact::getByURL($item['owner-link'], false);
 571                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 572                         if ($author['type'] != 'Group') {
 573                                 Logger::log('Send follow request for ' . $item['uri'] . ' (' . $stored . ') to ' . $item['author-link'], Logger::DEBUG);
 574                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 575                         }
 576                 }
 577         }
 578
 579         private static function storeTags(int $uriid, array $tags = null)
 580         {
 581                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 582                 DBA::delete('tag', ['uri-id' => $uriid]);
 583
 584                 foreach ($tags as $tag) {
 585                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 586                                 continue;
 587                         }
 588
 589                         $fields = ['uri-id' => $uriid, 'name' => $tag['name']];
 590
 591                         if ($tag['type'] == 'Mention') {
 592                                 $fields['type'] = Term::MENTION;
 593
 594                                 if (substr($fields['name'], 0, 1) == Term::TAG_CHARACTER[Term::MENTION]) {
 595                                         $fields['name'] = substr($fields['name'], 1);
 596                                 } elseif (substr($fields['name'], 0, 1) == Term::TAG_CHARACTER[Term::EXCLUSIVE_MENTION]) {
 597                                         $fields['type'] = Term::EXCLUSIVE_MENTION;
 598                                         $fields['name'] = substr($fields['name'], 1);
 599                                 } elseif (substr($fields['name'], 0, 1) == Term::TAG_CHARACTER[Term::IMPLICIT_MENTION]) {
 600                                         $fields['type'] = Term::IMPLICIT_MENTION;
 601                                         $fields['name'] = substr($fields['name'], 1);
 602                                 }
 603                         } elseif ($tag['type'] == 'Hashtag') {
 604                                 $fields['type'] = Term::HASHTAG;
 605                                 if (substr($fields['name'], 0, 1) == Term::TAG_CHARACTER[Term::HASHTAG]) {
 606                                         $fields['name'] = substr($fields['name'], 1);
 607                                 }
 608                         }
 609
 610                         if (empty($fields['name'])) {
 611                                 continue;
 612                         } else {
 613                                 $fields['name'] = substr($fields['name'], 0, 64);
 614                         }
 615
 616                         if (!empty($tag['href'] && ($tag['href'] != $tag['name']))) {
 617                                 $fields['url'] = $tag['href'];
 618                         }
 619
 620                         DBA::insert('tag', $fields, true);
 621
 622                         Logger::info('Stored tag/mention', ['uriid' => $uriid, 'tag' => $tag, 'fields' => $fields]);
 623                 }
 624         }
 625
 626         /**
 627          * Creates an mail post
 628          *
 629          * @param array $activity Activity data
 630          * @param array $item     item array
 631          * @return int|bool New mail table row id or false on error
 632          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 633          */
 634         private static function postMail($activity, $item)
 635         {
 636                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 637                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 638                         return false;
 639                 }
 640
 641                 Logger::info('Direct Message', $item);
 642
 643                 $msg = [];
 644                 $msg['uid'] = $item['uid'];
 645
 646                 $msg['contact-id'] = $item['contact-id'];
 647
 648                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 649                 $msg['from-name'] = $contact['name'];
 650                 $msg['from-url'] = $contact['url'];
 651                 $msg['from-photo'] = $contact['photo'];
 652
 653                 $msg['uri'] = $item['uri'];
 654                 $msg['created'] = $item['created'];
 655
 656                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 657                 if (DBA::isResult($parent)) {
 658                         $msg['parent-uri'] = $parent['parent-uri'];
 659                         $msg['title'] = $parent['title'];
 660                 } else {
 661                         $msg['parent-uri'] = $item['thr-parent'];
 662
 663                         if (!empty($item['title'])) {
 664                                 $msg['title'] = $item['title'];
 665                         } elseif (!empty($item['content-warning'])) {
 666                                 $msg['title'] = $item['content-warning'];
 667                         } else {
 668                                 // Trying to generate a title out of the body
 669                                 $title = $item['body'];
 670
 671                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 672                                         $title = $matches[3];
 673                                 }
 674
 675                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, 2, true), 0));
 676
 677                                 if (strlen($title) > 20) {
 678                                         $title = substr($title, 0, 20) . '...';
 679                                 }
 680
 681                                 $msg['title'] = $title;
 682                         }
 683                 }
 684                 $msg['body'] = $item['body'];
 685
 686                 return Mail::insert($msg);
 687         }
 688
 689         /**
 690          * Fetches missing posts
 691          *
 692          * @param string $url message URL
 693          * @param array $child activity array with the child of this message
 694          * @return string fetched message URL
 695          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 696          */
 697         public static function fetchMissingActivity($url, $child = [])
 698         {
 699                 if (!empty($child['receiver'])) {
 700                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 701                 } else {
 702                         $uid = 0;
 703                 }
 704
 705                 $object = ActivityPub::fetchContent($url, $uid);
 706                 if (empty($object)) {
 707                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 708                         return '';
 709                 }
 710
 711                 if (empty($object['id'])) {
 712                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 713                         return '';
 714                 }
 715
 716                 if (!empty($child['author'])) {
 717                         $actor = $child['author'];
 718                 } elseif (!empty($object['actor'])) {
 719                         $actor = $object['actor'];
 720                 } elseif (!empty($object['attributedTo'])) {
 721                         $actor = $object['attributedTo'];
 722                 } else {
 723                         // Shouldn't happen
 724                         $actor = '';
 725                 }
 726
 727                 if (!empty($object['published'])) {
 728                         $published = $object['published'];
 729                 } elseif (!empty($child['published'])) {
 730                         $published = $child['published'];
 731                 } else {
 732                         $published = DateTimeFormat::utcNow();
 733                 }
 734
 735                 $activity = [];
 736                 $activity['@context'] = $object['@context'];
 737                 unset($object['@context']);
 738                 $activity['id'] = $object['id'];
 739                 $activity['to'] = $object['to'] ?? [];
 740                 $activity['cc'] = $object['cc'] ?? [];
 741                 $activity['actor'] = $actor;
 742                 $activity['object'] = $object;
 743                 $activity['published'] = $published;
 744                 $activity['type'] = 'Create';
 745
 746                 $ldactivity = JsonLD::compact($activity);
 747
 748                 $ldactivity['thread-completion'] = true;
 749
 750                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity));
 751
 752                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 753
 754                 return $activity['id'];
 755         }
 756
 757         /**
 758          * perform a "follow" request
 759          *
 760          * @param array $activity
 761          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 762          * @throws \ImagickException
 763          */
 764         public static function followUser($activity)
 765         {
 766                 $uid = User::getIdForURL($activity['object_id']);
 767                 if (empty($uid)) {
 768                         return;
 769                 }
 770
 771                 $owner = User::getOwnerDataById($uid);
 772
 773                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 774                 if (!empty($cid)) {
 775                         self::switchContact($cid);
 776                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 777                         $contact = DBA::selectFirst('contact', [], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 778                 } else {
 779                         $contact = [];
 780                 }
 781
 782                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 783                         'author-link' => $activity['actor']];
 784
 785                 $note = Strings::escapeTags(trim($activity['content'] ?? ''));
 786
 787                 // Ensure that the contact has got the right network type
 788                 self::switchContact($item['author-id']);
 789
 790                 $result = Contact::addRelationship($owner, $contact, $item, false, $note);
 791                 if ($result === true) {
 792                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $item['author-id'], $owner['uid']);
 793                 }
 794
 795                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 796                 if (empty($cid)) {
 797                         return;
 798                 }
 799
 800                 if (empty($contact)) {
 801                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 802                 }
 803
 804                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 805         }
 806
 807         /**
 808          * Update the given profile
 809          *
 810          * @param array $activity
 811          * @throws \Exception
 812          */
 813         public static function updatePerson($activity)
 814         {
 815                 if (empty($activity['object_id'])) {
 816                         return;
 817                 }
 818
 819                 Logger::log('Updating profile for ' . $activity['object_id'], Logger::DEBUG);
 820                 Contact::updateFromProbeByURL($activity['object_id'], true);
 821         }
 822
 823         /**
 824          * Delete the given profile
 825          *
 826          * @param array $activity
 827          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 828          */
 829         public static function deletePerson($activity)
 830         {
 831                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 832                         Logger::log('Empty object id or actor.', Logger::DEBUG);
 833                         return;
 834                 }
 835
 836                 if ($activity['object_id'] != $activity['actor']) {
 837                         Logger::log('Object id does not match actor.', Logger::DEBUG);
 838                         return;
 839                 }
 840
 841                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 842                 while ($contact = DBA::fetch($contacts)) {
 843                         Contact::remove($contact['id']);
 844                 }
 845                 DBA::close($contacts);
 846
 847                 Logger::log('Deleted contact ' . $activity['object_id'], Logger::DEBUG);
 848         }
 849
 850         /**
 851          * Accept a follow request
 852          *
 853          * @param array $activity
 854          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 855          * @throws \ImagickException
 856          */
 857         public static function acceptFollowUser($activity)
 858         {
 859                 $uid = User::getIdForURL($activity['object_actor']);
 860                 if (empty($uid)) {
 861                         return;
 862                 }
 863
 864                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 865                 if (empty($cid)) {
 866                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 867                         return;
 868                 }
 869
 870                 self::switchContact($cid);
 871
 872                 $fields = ['pending' => false];
 873
 874                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
 875                 if ($contact['rel'] == Contact::FOLLOWER) {
 876                         $fields['rel'] = Contact::FRIEND;
 877                 }
 878
 879                 $condition = ['id' => $cid];
 880                 DBA::update('contact', $fields, $condition);
 881                 Logger::log('Accept contact request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 882         }
 883
 884         /**
 885          * Reject a follow request
 886          *
 887          * @param array $activity
 888          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 889          * @throws \ImagickException
 890          */
 891         public static function rejectFollowUser($activity)
 892         {
 893                 $uid = User::getIdForURL($activity['object_actor']);
 894                 if (empty($uid)) {
 895                         return;
 896                 }
 897
 898                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 899                 if (empty($cid)) {
 900                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 901                         return;
 902                 }
 903
 904                 self::switchContact($cid);
 905
 906                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
 907                         Contact::remove($cid);
 908                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . ' - contact had been removed.', Logger::DEBUG);
 909                 } else {
 910                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . '.', Logger::DEBUG);
 911                 }
 912         }
 913
 914         /**
 915          * Undo activity like "like" or "dislike"
 916          *
 917          * @param array $activity
 918          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 919          * @throws \ImagickException
 920          */
 921         public static function undoActivity($activity)
 922         {
 923                 if (empty($activity['object_id'])) {
 924                         return;
 925                 }
 926
 927                 if (empty($activity['object_actor'])) {
 928                         return;
 929                 }
 930
 931                 $author_id = Contact::getIdForURL($activity['object_actor']);
 932                 if (empty($author_id)) {
 933                         return;
 934                 }
 935
 936                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
 937         }
 938
 939         /**
 940          * Activity to remove a follower
 941          *
 942          * @param array $activity
 943          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 944          * @throws \ImagickException
 945          */
 946         public static function undoFollowUser($activity)
 947         {
 948                 $uid = User::getIdForURL($activity['object_object']);
 949                 if (empty($uid)) {
 950                         return;
 951                 }
 952
 953                 $owner = User::getOwnerDataById($uid);
 954
 955                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 956                 if (empty($cid)) {
 957                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 958                         return;
 959                 }
 960
 961                 self::switchContact($cid);
 962
 963                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
 964                 if (!DBA::isResult($contact)) {
 965                         return;
 966                 }
 967
 968                 Contact::removeFollower($owner, $contact);
 969                 Logger::log('Undo following request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 970         }
 971
 972         /**
 973          * Switches a contact to AP if needed
 974          *
 975          * @param integer $cid Contact ID
 976          * @throws \Exception
 977          */
 978         private static function switchContact($cid)
 979         {
 980                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
 981                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
 982                         return;
 983                 }
 984
 985                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
 986                 Contact::updateFromProbe($cid);
 987         }
 988
 989         /**
 990          * Collects implicit mentions like:
 991          * - the author of the parent item
 992          * - all the mentioned conversants in the parent item
 993          *
 994          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
 995          * @return array
 996          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 997          */
 998         private static function getImplicitMentionList(array $parent)
 999         {
1000                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1001                         return [];
1002                 }
1003
1004                 $parent_terms = Term::tagArrayFromItemId($parent['id'], [Term::MENTION, Term::IMPLICIT_MENTION]);
1005
1006                 $parent_author = Contact::getDetailsByURL($parent['author-link'], 0);
1007
1008                 $implicit_mentions = [];
1009                 if (empty($parent_author)) {
1010                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
1011                 } else {
1012                         $implicit_mentions[] = $parent_author['url'];
1013                         $implicit_mentions[] = $parent_author['nurl'];
1014                         $implicit_mentions[] = $parent_author['alias'];
1015                 }
1016
1017                 if (!empty($parent['alias'])) {
1018                         $implicit_mentions[] = $parent['alias'];
1019                 }
1020
1021                 foreach ($parent_terms as $term) {
1022                         $contact = Contact::getDetailsByURL($term['url'], 0);
1023                         if (!empty($contact)) {
1024                                 $implicit_mentions[] = $contact['url'];
1025                                 $implicit_mentions[] = $contact['nurl'];
1026                                 $implicit_mentions[] = $contact['alias'];
1027                         }
1028                 }
1029
1030                 return $implicit_mentions;
1031         }
1032
1033         /**
1034          * Strips from the body prepended implicit mentions
1035          *
1036          * @param string $body
1037          * @param array $potential_mentions
1038          * @return string
1039          */
1040         private static function removeImplicitMentionsFromBody($body, array $potential_mentions)
1041         {
1042                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1043                         return $body;
1044                 }
1045
1046                 $kept_mentions = [];
1047
1048                 // Extract one prepended mention at a time from the body
1049                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1050                         if (!in_array($matches[2], $potential_mentions)) {
1051                                 $kept_mentions[] = $matches[1];
1052                         }
1053
1054                         $body = $matches[3];
1055                 }
1056
1057                 // Re-appending the kept mentions to the body after extraction
1058                 $kept_mentions[] = $body;
1059
1060                 return implode('', $kept_mentions);
1061         }
1062
1063         private static function convertImplicitMentionsInTags($activity_tags, array $potential_mentions)
1064         {
1065                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1066                         return $activity_tags;
1067                 }
1068
1069                 foreach ($activity_tags as $index => $tag) {
1070                         if (in_array($tag['href'], $potential_mentions)) {
1071                                 $activity_tags[$index]['name'] = preg_replace(
1072                                         '/' . preg_quote(Term::TAG_CHARACTER[Term::MENTION], '/') . '/',
1073                                         Term::TAG_CHARACTER[Term::IMPLICIT_MENTION],
1074                                         $activity_tags[$index]['name'],
1075                                         1
1076                                 );
1077                         }
1078                 }
1079
1080                 return $activity_tags;
1081         }
1082 }