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'], 0, false);
 230                 $item['owner-link'] = $activity['actor'];
 231                 $item['owner-id'] = Contact::getIdForURL($activity['actor'], 0, false);
 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                 $stored = false;
 518
 519                 foreach ($activity['receiver'] as $receiver) {
 520                         if ($receiver == -1) {
 521                                 continue;
 522                         }
 523
 524                         $item['uid'] = $receiver;
 525
 526                         if ($item['isForum'] ?? false) {
 527                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver, false);
 528                         } else {
 529                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, false);
 530                         }
 531
 532                         if (($receiver != 0) && empty($item['contact-id'])) {
 533                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, false);
 534                         }
 535
 536                         if (!empty($activity['directmessage'])) {
 537                                 self::postMail($activity, $item);
 538                                 continue;
 539                         }
 540
 541                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 542                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 543
 544                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 545                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 546                                 }
 547
 548                                 if ($skip) {
 549                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 550                                         continue;
 551                                 }
 552
 553                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 554                         }
 555
 556                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 557                                 self::createEvent($activity, $item);
 558                         }
 559
 560                         $item_id = Item::insert($item);
 561                         if ($item_id) {
 562                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 563                         } else {
 564                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 565                         }
 566
 567                         if ($item['uid'] == 0) {
 568                                 $stored = $item_id;
 569                         }
 570                 }
 571
 572                 // Store send a follow request for every reshare - but only when the item had been stored
 573                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 574                         $author = APContact::getByURL($item['owner-link'], false);
 575                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 576                         if ($author['type'] != 'Group') {
 577                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 578                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 579                         }
 580                 }
 581         }
 582
 583         /**
 584          * Store tags and mentions into the tag table
 585          *
 586          * @param integer $uriid
 587          * @param array $tags
 588          */
 589         private static function storeTags(int $uriid, array $tags = null)
 590         {
 591                 foreach ($tags as $tag) {
 592                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 593                                 continue;
 594                         }
 595
 596                         $hash = substr($tag['name'], 0, 1);
 597
 598                         if ($tag['type'] == 'Mention') {
 599                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 600                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 601                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 602                                         $tag['name'] = substr($tag['name'], 1);
 603                                 }
 604                                 $type = Tag::IMPLICIT_MENTION;
 605
 606                                 if (!empty($tag['href'])) {
 607                                         $apcontact = APContact::getByURL($tag['href']);
 608                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 609                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 610                                         }
 611                                 }
 612                         } elseif ($tag['type'] == 'Hashtag') {
 613                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 614                                         $tag['name'] = substr($tag['name'], 1);
 615                                 }
 616                                 $type = Tag::HASHTAG;
 617                         }
 618
 619                         if (empty($tag['name'])) {
 620                                 continue;
 621                         }
 622
 623                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 624                 }
 625         }
 626
 627         /**
 628          * Creates an mail post
 629          *
 630          * @param array $activity Activity data
 631          * @param array $item     item array
 632          * @return int|bool New mail table row id or false on error
 633          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 634          */
 635         private static function postMail($activity, $item)
 636         {
 637                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 638                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 639                         return false;
 640                 }
 641
 642                 Logger::info('Direct Message', $item);
 643
 644                 $msg = [];
 645                 $msg['uid'] = $item['uid'];
 646
 647                 $msg['contact-id'] = $item['contact-id'];
 648
 649                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 650                 $msg['from-name'] = $contact['name'];
 651                 $msg['from-url'] = $contact['url'];
 652                 $msg['from-photo'] = $contact['photo'];
 653
 654                 $msg['uri'] = $item['uri'];
 655                 $msg['created'] = $item['created'];
 656
 657                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 658                 if (DBA::isResult($parent)) {
 659                         $msg['parent-uri'] = $parent['parent-uri'];
 660                         $msg['title'] = $parent['title'];
 661                 } else {
 662                         $msg['parent-uri'] = $item['thr-parent'];
 663
 664                         if (!empty($item['title'])) {
 665                                 $msg['title'] = $item['title'];
 666                         } elseif (!empty($item['content-warning'])) {
 667                                 $msg['title'] = $item['content-warning'];
 668                         } else {
 669                                 // Trying to generate a title out of the body
 670                                 $title = $item['body'];
 671
 672                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 673                                         $title = $matches[3];
 674                                 }
 675
 676                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, BBCode::API, true), 0));
 677
 678                                 if (strlen($title) > 20) {
 679                                         $title = substr($title, 0, 20) . '...';
 680                                 }
 681
 682                                 $msg['title'] = $title;
 683                         }
 684                 }
 685                 $msg['body'] = $item['body'];
 686
 687                 return Mail::insert($msg);
 688         }
 689
 690         /**
 691          * Fetches missing posts
 692          *
 693          * @param string $url message URL
 694          * @param array $child activity array with the child of this message
 695          * @return string fetched message URL
 696          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 697          */
 698         public static function fetchMissingActivity($url, $child = [])
 699         {
 700                 if (!empty($child['receiver'])) {
 701                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 702                 } else {
 703                         $uid = 0;
 704                 }
 705
 706                 $object = ActivityPub::fetchContent($url, $uid);
 707                 if (empty($object)) {
 708                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 709                         return '';
 710                 }
 711
 712                 if (empty($object['id'])) {
 713                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 714                         return '';
 715                 }
 716
 717                 if (!empty($child['author'])) {
 718                         $actor = $child['author'];
 719                 } elseif (!empty($object['actor'])) {
 720                         $actor = $object['actor'];
 721                 } elseif (!empty($object['attributedTo'])) {
 722                         $actor = $object['attributedTo'];
 723                 } else {
 724                         // Shouldn't happen
 725                         $actor = '';
 726                 }
 727
 728                 if (!empty($object['published'])) {
 729                         $published = $object['published'];
 730                 } elseif (!empty($child['published'])) {
 731                         $published = $child['published'];
 732                 } else {
 733                         $published = DateTimeFormat::utcNow();
 734                 }
 735
 736                 $activity = [];
 737                 $activity['@context'] = $object['@context'];
 738                 unset($object['@context']);
 739                 $activity['id'] = $object['id'];
 740                 $activity['to'] = $object['to'] ?? [];
 741                 $activity['cc'] = $object['cc'] ?? [];
 742                 $activity['actor'] = $actor;
 743                 $activity['object'] = $object;
 744                 $activity['published'] = $published;
 745                 $activity['type'] = 'Create';
 746
 747                 $ldactivity = JsonLD::compact($activity);
 748
 749                 $ldactivity['thread-completion'] = true;
 750
 751                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity));
 752
 753                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 754
 755                 return $activity['id'];
 756         }
 757
 758         /**
 759          * perform a "follow" request
 760          *
 761          * @param array $activity
 762          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 763          * @throws \ImagickException
 764          */
 765         public static function followUser($activity)
 766         {
 767                 $uid = User::getIdForURL($activity['object_id']);
 768                 if (empty($uid)) {
 769                         return;
 770                 }
 771
 772                 $owner = User::getOwnerDataById($uid);
 773
 774                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 775                 if (!empty($cid)) {
 776                         self::switchContact($cid);
 777                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 778                         $contact = DBA::selectFirst('contact', [], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 779                 } else {
 780                         $contact = [];
 781                 }
 782
 783                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 784                         'author-link' => $activity['actor']];
 785
 786                 $note = Strings::escapeTags(trim($activity['content'] ?? ''));
 787
 788                 // Ensure that the contact has got the right network type
 789                 self::switchContact($item['author-id']);
 790
 791                 $result = Contact::addRelationship($owner, $contact, $item, false, $note);
 792                 if ($result === true) {
 793                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
 794                 }
 795
 796                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 797                 if (empty($cid)) {
 798                         return;
 799                 }
 800
 801                 if (empty($contact)) {
 802                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 803                 }
 804
 805                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 806         }
 807
 808         /**
 809          * Update the given profile
 810          *
 811          * @param array $activity
 812          * @throws \Exception
 813          */
 814         public static function updatePerson($activity)
 815         {
 816                 if (empty($activity['object_id'])) {
 817                         return;
 818                 }
 819
 820                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
 821                 Contact::updateFromProbeByURL($activity['object_id'], true);
 822         }
 823
 824         /**
 825          * Delete the given profile
 826          *
 827          * @param array $activity
 828          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 829          */
 830         public static function deletePerson($activity)
 831         {
 832                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 833                         Logger::info('Empty object id or actor.');
 834                         return;
 835                 }
 836
 837                 if ($activity['object_id'] != $activity['actor']) {
 838                         Logger::info('Object id does not match actor.');
 839                         return;
 840                 }
 841
 842                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 843                 while ($contact = DBA::fetch($contacts)) {
 844                         Contact::remove($contact['id']);
 845                 }
 846                 DBA::close($contacts);
 847
 848                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
 849         }
 850
 851         /**
 852          * Accept a follow request
 853          *
 854          * @param array $activity
 855          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 856          * @throws \ImagickException
 857          */
 858         public static function acceptFollowUser($activity)
 859         {
 860                 $uid = User::getIdForURL($activity['object_actor']);
 861                 if (empty($uid)) {
 862                         return;
 863                 }
 864
 865                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 866                 if (empty($cid)) {
 867                         Logger::info('No contact found', ['actor' => $activity['actor']]);
 868                         return;
 869                 }
 870
 871                 self::switchContact($cid);
 872
 873                 $fields = ['pending' => false];
 874
 875                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
 876                 if ($contact['rel'] == Contact::FOLLOWER) {
 877                         $fields['rel'] = Contact::FRIEND;
 878                 }
 879
 880                 $condition = ['id' => $cid];
 881                 DBA::update('contact', $fields, $condition);
 882                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
 883         }
 884
 885         /**
 886          * Reject a follow request
 887          *
 888          * @param array $activity
 889          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 890          * @throws \ImagickException
 891          */
 892         public static function rejectFollowUser($activity)
 893         {
 894                 $uid = User::getIdForURL($activity['object_actor']);
 895                 if (empty($uid)) {
 896                         return;
 897                 }
 898
 899                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 900                 if (empty($cid)) {
 901                         Logger::info('No contact found', ['actor' => $activity['actor']]);
 902                         return;
 903                 }
 904
 905                 self::switchContact($cid);
 906
 907                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
 908                         Contact::remove($cid);
 909                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
 910                 } else {
 911                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
 912                 }
 913         }
 914
 915         /**
 916          * Undo activity like "like" or "dislike"
 917          *
 918          * @param array $activity
 919          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 920          * @throws \ImagickException
 921          */
 922         public static function undoActivity($activity)
 923         {
 924                 if (empty($activity['object_id'])) {
 925                         return;
 926                 }
 927
 928                 if (empty($activity['object_actor'])) {
 929                         return;
 930                 }
 931
 932                 $author_id = Contact::getIdForURL($activity['object_actor']);
 933                 if (empty($author_id)) {
 934                         return;
 935                 }
 936
 937                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
 938         }
 939
 940         /**
 941          * Activity to remove a follower
 942          *
 943          * @param array $activity
 944          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 945          * @throws \ImagickException
 946          */
 947         public static function undoFollowUser($activity)
 948         {
 949                 $uid = User::getIdForURL($activity['object_object']);
 950                 if (empty($uid)) {
 951                         return;
 952                 }
 953
 954                 $owner = User::getOwnerDataById($uid);
 955
 956                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 957                 if (empty($cid)) {
 958                         Logger::info('No contact found', ['actor' => $activity['actor']]);
 959                         return;
 960                 }
 961
 962                 self::switchContact($cid);
 963
 964                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
 965                 if (!DBA::isResult($contact)) {
 966                         return;
 967                 }
 968
 969                 Contact::removeFollower($owner, $contact);
 970                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
 971         }
 972
 973         /**
 974          * Switches a contact to AP if needed
 975          *
 976          * @param integer $cid Contact ID
 977          * @throws \Exception
 978          */
 979         private static function switchContact($cid)
 980         {
 981                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
 982                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
 983                         return;
 984                 }
 985
 986                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
 987                 Contact::updateFromProbe($cid);
 988         }
 989
 990         /**
 991          * Collects implicit mentions like:
 992          * - the author of the parent item
 993          * - all the mentioned conversants in the parent item
 994          *
 995          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
 996          * @return array
 997          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 998          */
 999         private static function getImplicitMentionList(array $parent)
1000         {
1001                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1002
1003                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1004
1005                 $implicit_mentions = [];
1006                 if (empty($parent_author['url'])) {
1007                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
1008                 } else {
1009                         $implicit_mentions[] = $parent_author['url'];
1010                         $implicit_mentions[] = $parent_author['nurl'];
1011                         $implicit_mentions[] = $parent_author['alias'];
1012                 }
1013
1014                 if (!empty($parent['alias'])) {
1015                         $implicit_mentions[] = $parent['alias'];
1016                 }
1017
1018                 foreach ($parent_terms as $term) {
1019                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1020                         if (!empty($contact['url'])) {
1021                                 $implicit_mentions[] = $contact['url'];
1022                                 $implicit_mentions[] = $contact['nurl'];
1023                                 $implicit_mentions[] = $contact['alias'];
1024                         }
1025                 }
1026
1027                 return $implicit_mentions;
1028         }
1029
1030         /**
1031          * Strips from the body prepended implicit mentions
1032          *
1033          * @param string $body
1034          * @param array $parent
1035          * @return string
1036          */
1037         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1038         {
1039                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1040                         return $body;
1041                 }
1042
1043                 $potential_mentions = self::getImplicitMentionList($parent);
1044
1045                 $kept_mentions = [];
1046
1047                 // Extract one prepended mention at a time from the body
1048                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1049                         if (!in_array($matches[2], $potential_mentions)) {
1050                                 $kept_mentions[] = $matches[1];
1051                         }
1052
1053                         $body = $matches[3];
1054                 }
1055
1056                 // Re-appending the kept mentions to the body after extraction
1057                 $kept_mentions[] = $body;
1058
1059                 return implode('', $kept_mentions);
1060         }
1061 }