src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol\ActivityPub;
  23
  24 use Friendica\Content\Text\BBCode;
  25 use Friendica\Content\Text\HTML;
  26 use Friendica\Core\Logger;
  27 use Friendica\Core\Protocol;
  28 use Friendica\Database\DBA;
  29 use Friendica\DI;
  30 use Friendica\Model\APContact;
  31 use Friendica\Model\Contact;
  32 use Friendica\Model\Conversation;
  33 use Friendica\Model\Event;
  34 use Friendica\Model\Item;
  35 use Friendica\Model\ItemURI;
  36 use Friendica\Model\Mail;
  37 use Friendica\Model\Tag;
  38 use Friendica\Model\Term;
  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          * Constructs a string with tags for a given tag array
  85          *
  86          * @param array   $tags
  87          * @param boolean $sensitive
  88          * @return string with tags
  89          */
  90         private static function constructTagString(array $tags = null, $sensitive = false)
  91         {
  92                 if (empty($tags)) {
  93                         return '';
  94                 }
  95
  96                 $tag_text = '';
  97                 foreach ($tags as $tag) {
  98                         if (in_array($tag['type'] ?? '', ['Mention', 'Hashtag'])) {
  99                                 if (!empty($tag_text)) {
 100                                         $tag_text .= ',';
 101                                 }
 102
 103                                 $tag_text .= substr($tag['name'], 0, 1) . '[url=' . $tag['href'] . ']' . substr($tag['name'], 1) . '[/url]';
 104                         }
 105                 }
 106
 107                 /// @todo add nsfw for $sensitive
 108
 109                 return $tag_text;
 110         }
 111
 112         /**
 113          * Add attachment data to the item array
 114          *
 115          * @param array   $activity
 116          * @param array   $item
 117          *
 118          * @return array array
 119          */
 120         private static function constructAttachList($activity, $item)
 121         {
 122                 if (empty($activity['attachments'])) {
 123                         return $item;
 124                 }
 125
 126                 foreach ($activity['attachments'] as $attach) {
 127                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 128                         if ($filetype == 'image') {
 129                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 130                                         continue;
 131                                 }
 132
 133                                 if (empty($attach['name'])) {
 134                                         $item['body'] .= "\n[img]" . $attach['url'] . '[/img]';
 135                                 } else {
 136                                         $item['body'] .= "\n[img=" . $attach['url'] . ']' . $attach['name'] . '[/img]';
 137                                 }
 138                         } elseif ($filetype == 'audio') {
 139                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 140                                         continue;
 141                                 }
 142
 143                                 $item['body'] .= "\n[audio]" . $attach['url'] . '[/audio]';
 144                         } elseif ($filetype == 'video') {
 145                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 146                                         continue;
 147                                 }
 148
 149                                 $item['body'] .= "\n[video]" . $attach['url'] . '[/video]';
 150                         } else {
 151                                 if (!empty($item["attach"])) {
 152                                         $item["attach"] .= ',';
 153                                 } else {
 154                                         $item["attach"] = '';
 155                                 }
 156                                 if (!isset($attach['length'])) {
 157                                         $attach['length'] = "0";
 158                                 }
 159                                 $item["attach"] .= '[attach]href="'.$attach['url'].'" length="'.$attach['length'].'" type="'.$attach['mediaType'].'" title="'.($attach['name'] ?? '') .'"[/attach]';
 160                         }
 161                 }
 162
 163                 return $item;
 164         }
 165
 166         /**
 167          * Updates a message
 168          *
 169          * @param array $activity Activity array
 170          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 171          */
 172         public static function updateItem($activity)
 173         {
 174                 $item = Item::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity'], ['uri' => $activity['id']]);
 175                 if (!DBA::isResult($item)) {
 176                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 177                         self::createItem($activity);
 178                         return;
 179                 }
 180
 181                 $item['changed'] = DateTimeFormat::utcNow();
 182                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 183
 184                 $item = self::processContent($activity, $item);
 185                 if (empty($item)) {
 186                         return;
 187                 }
 188
 189                 Item::update($item, ['uri' => $activity['id']]);
 190         }
 191
 192         /**
 193          * Prepares data for a message
 194          *
 195          * @param array $activity Activity array
 196          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 197          * @throws \ImagickException
 198          */
 199         public static function createItem($activity)
 200         {
 201                 $item = [];
 202                 $item['verb'] = Activity::POST;
 203                 $item['thr-parent'] = $activity['reply-to-id'];
 204
 205                 if ($activity['reply-to-id'] == $activity['id']) {
 206                         $item['gravity'] = GRAVITY_PARENT;
 207                         $item['object-type'] = Activity\ObjectType::NOTE;
 208                 } else {
 209                         $item['gravity'] = GRAVITY_COMMENT;
 210                         $item['object-type'] = Activity\ObjectType::COMMENT;
 211
 212                         // Ensure that the comment reaches all receivers of the referring post
 213                         $activity['receiver'] = self::addReceivers($activity);
 214                 }
 215
 216                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Item::exists(['uri' => $activity['reply-to-id']])) {
 217                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 218                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 219                 }
 220
 221                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 222
 223                 self::postItem($activity, $item);
 224         }
 225
 226         /**
 227          * Delete items
 228          *
 229          * @param array $activity
 230          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 231          * @throws \ImagickException
 232          */
 233         public static function deleteItem($activity)
 234         {
 235                 $owner = Contact::getIdForURL($activity['actor']);
 236
 237                 Logger::log('Deleting item ' . $activity['object_id'] . ' from ' . $owner, Logger::DEBUG);
 238                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 239         }
 240
 241         /**
 242          * Prepare the item array for an activity
 243          *
 244          * @param array $activity Activity array
 245          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 246          * @throws \ImagickException
 247          */
 248         public static function addTag($activity)
 249         {
 250                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 251                         return;
 252                 }
 253
 254                 foreach ($activity['receiver'] as $receiver) {
 255                         $item = Item::selectFirst(['id', 'uri-id', 'tag', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 256                         if (!DBA::isResult($item)) {
 257                                 // We don't fetch missing content for this purpose
 258                                 continue;
 259                         }
 260
 261                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 262                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 263                                 continue;
 264                         }
 265
 266                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 267
 268                         // To-Do:
 269                         // - Check if "blocktag" is set
 270                         // - Check if actor is a contact
 271
 272                         if (!stristr($item['tag'], trim($activity['object_content']))) {
 273                                 $tag = $item['tag'] . (strlen($item['tag']) ? ',' : '') . '#[url=' . $activity['object_id'] . ']'. $activity['object_content'] . '[/url]';
 274                                 Item::update(['tag' => $tag], ['id' => $item['id']]);
 275                                 Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 276                         }
 277                 }
 278         }
 279
 280         /**
 281          * Add users to the receiver list of the given public activity.
 282          * This is used to ensure that the activity will be stored in every thread.
 283          *
 284          * @param array $activity Activity array
 285          * @return array Modified receiver list
 286          */
 287         private static function addReceivers(array $activity)
 288         {
 289                 if (!in_array(0, $activity['receiver'])) {
 290                         // Private activities will not be modified
 291                         return $activity['receiver'];
 292                 }
 293
 294                 // Add all owners of the referring item to the receivers
 295                 $original = $receivers = $activity['receiver'];
 296                 $items = Item::select(['uid'], ['uri' => $activity['object_id']]);
 297                 while ($item = DBA::fetch($items)) {
 298                         $receivers['uid:' . $item['uid']] = $item['uid'];
 299                 }
 300                 DBA::close($items);
 301
 302                 if (count($original) != count($receivers)) {
 303                         Logger::info('Improved data', ['id' => $activity['id'], 'object' => $activity['object_id'], 'original' => $original, 'improved' => $receivers]);
 304                 }
 305
 306                 return $receivers;
 307         }
 308
 309         /**
 310          * Prepare the item array for an activity
 311          *
 312          * @param array  $activity Activity array
 313          * @param string $verb     Activity verb
 314          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 315          * @throws \ImagickException
 316          */
 317         public static function createActivity($activity, $verb)
 318         {
 319                 $item = [];
 320                 $item['verb'] = $verb;
 321                 $item['thr-parent'] = $activity['object_id'];
 322                 $item['gravity'] = GRAVITY_ACTIVITY;
 323                 $item['object-type'] = Activity\ObjectType::NOTE;
 324
 325                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 326
 327                 $activity['receiver'] = self::addReceivers($activity);
 328
 329                 self::postItem($activity, $item);
 330         }
 331
 332         /**
 333          * Create an event
 334          *
 335          * @param array $activity Activity array
 336          * @param array $item
 337          * @throws \Exception
 338          */
 339         public static function createEvent($activity, $item)
 340         {
 341                 $event['summary']  = HTML::toBBCode($activity['name']);
 342                 $event['desc']     = HTML::toBBCode($activity['content']);
 343                 $event['start']    = $activity['start-time'];
 344                 $event['finish']   = $activity['end-time'];
 345                 $event['nofinish'] = empty($event['finish']);
 346                 $event['location'] = $activity['location'];
 347                 $event['adjust']   = true;
 348                 $event['cid']      = $item['contact-id'];
 349                 $event['uid']      = $item['uid'];
 350                 $event['uri']      = $item['uri'];
 351                 $event['edited']   = $item['edited'];
 352                 $event['private']  = $item['private'];
 353                 $event['guid']     = $item['guid'];
 354                 $event['plink']    = $item['plink'];
 355
 356                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 357                 $ev = DBA::selectFirst('event', ['id'], $condition);
 358                 if (DBA::isResult($ev)) {
 359                         $event['id'] = $ev['id'];
 360                 }
 361
 362                 $event_id = Event::store($event);
 363                 Logger::log('Event '.$event_id.' was stored', Logger::DEBUG);
 364         }
 365
 366         /**
 367          * Process the content
 368          *
 369          * @param array $activity Activity array
 370          * @param array $item
 371          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 372          * @throws \Exception
 373          */
 374         private static function processContent($activity, $item)
 375         {
 376                 $item['title'] = HTML::toBBCode($activity['name']);
 377
 378                 if (!empty($activity['source'])) {
 379                         $item['body'] = $activity['source'];
 380                 } else {
 381                         $content = HTML::toBBCode($activity['content']);
 382
 383                         if (!empty($activity['emojis'])) {
 384                                 $content = self::replaceEmojis($content, $activity['emojis']);
 385                         }
 386
 387                         $content = self::convertMentions($content);
 388
 389                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 390                                 $item_private = !in_array(0, $activity['item_receiver']);
 391                                 $parent = Item::selectFirst(['id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 392                                 if (!DBA::isResult($parent)) {
 393                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 394                                         return false;
 395                                 }
 396                                 if ($item_private && ($parent['private'] == Item::PRIVATE)) {
 397                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 398                                         return false;
 399                                 }
 400
 401                                 $potential_implicit_mentions = self::getImplicitMentionList($parent);
 402                                 $content = self::removeImplicitMentionsFromBody($content, $potential_implicit_mentions);
 403                                 $activity['tags'] = self::convertImplicitMentionsInTags($activity['tags'], $potential_implicit_mentions);
 404                         }
 405                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 406                         $item['body'] = $content;
 407                 }
 408
 409                 $item['tag'] = self::constructTagString($activity['tags'], $activity['sensitive']);
 410
 411                 self::storeFromBody($item);
 412                 self::storeTags($item['uri-id'], $activity['tags']);
 413
 414                 $item['location'] = $activity['location'];
 415
 416                 if (!empty($item['latitude']) && !empty($item['longitude'])) {
 417                         $item['coord'] = $item['latitude'] . ' ' . $item['longitude'];
 418                 }
 419
 420                 $item['app'] = $activity['generator'];
 421
 422                 return $item;
 423         }
 424
 425         /**
 426          * Store hashtags and mentions
 427          *
 428          * @param array $item
 429          */
 430         private static function storeFromBody(array $item)
 431         {
 432                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 433                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 434
 435                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 436         }
 437
 438         /**
 439          * Generate a GUID out of an URL
 440          *
 441          * @param string $url message URL
 442          * @return string with GUID
 443          */
 444         private static function getGUIDByURL(string $url)
 445         {
 446                 $parsed = parse_url($url);
 447
 448                 $host_hash = hash('crc32', $parsed['host']);
 449
 450                 unset($parsed["scheme"]);
 451                 unset($parsed["host"]);
 452
 453                 $path = implode("/", $parsed);
 454
 455                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 456         }
 457
 458         /**
 459          * Creates an item post
 460          *
 461          * @param array $activity Activity data
 462          * @param array $item     item array
 463          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 464          * @throws \ImagickException
 465          */
 466         private static function postItem($activity, $item)
 467         {
 468                 /// @todo What to do with $activity['context']?
 469                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['thr-parent']])) {
 470                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 471                         return;
 472                 }
 473
 474                 $item['network'] = Protocol::ACTIVITYPUB;
 475                 $item['author-link'] = $activity['author'];
 476                 $item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
 477                 $item['owner-link'] = $activity['actor'];
 478                 $item['owner-id'] = Contact::getIdForURL($activity['actor'], 0, true);
 479
 480                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 481                         $item['private'] = Item::UNLISTED;
 482                 } elseif (in_array(0, $activity['receiver'])) {
 483                         $item['private'] = Item::PUBLIC;
 484                 } else {
 485                         $item['private'] = Item::PRIVATE;
 486                 }
 487
 488                 if (!empty($activity['raw'])) {
 489                         $item['source'] = $activity['raw'];
 490                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 491                         $item['conversation-href'] = $activity['context'] ?? '';
 492                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 493
 494                         if (isset($activity['push'])) {
 495                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 496                         }
 497                 }
 498
 499                 $isForum = false;
 500
 501                 if (!empty($activity['thread-completion'])) {
 502                         // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 503                         $item['causer-link'] = $item['owner-link'];
 504                         $item['causer-id'] = $item['owner-id'];
 505
 506                         Logger::info('Ignoring actor because of thread completion.', ['actor' => $item['owner-link']]);
 507                         $item['owner-link'] = $item['author-link'];
 508                         $item['owner-id'] = $item['author-id'];
 509                 } else {
 510                         $actor = APContact::getByURL($item['owner-link'], false);
 511                         $isForum = ($actor['type'] == 'Group');
 512                 }
 513
 514                 $item['uri'] = $activity['id'];
 515
 516                 $item['created'] = DateTimeFormat::utc($activity['published']);
 517                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 518                 $item['guid'] = $activity['diaspora:guid'] ?: $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 519
 520                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 521
 522                 $item = self::processContent($activity, $item);
 523                 if (empty($item)) {
 524                         return;
 525                 }
 526
 527                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 528
 529                 $item = self::constructAttachList($activity, $item);
 530
 531                 $stored = false;
 532
 533                 foreach ($activity['receiver'] as $receiver) {
 534                         if ($receiver == -1) {
 535                                 continue;
 536                         }
 537
 538                         $item['uid'] = $receiver;
 539
 540                         if ($isForum) {
 541                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver, true);
 542                         } else {
 543                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
 544                         }
 545
 546                         if (($receiver != 0) && empty($item['contact-id'])) {
 547                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
 548                         }
 549
 550                         if (!empty($activity['directmessage'])) {
 551                                 self::postMail($activity, $item);
 552                                 continue;
 553                         }
 554
 555                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 556                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 557
 558                                 if ($skip && (($activity['type'] == 'as:Announce') || $isForum)) {
 559                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 560                                 }
 561
 562                                 if ($skip) {
 563                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 564                                         continue;
 565                                 }
 566
 567                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 568                         }
 569
 570                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 571                                 self::createEvent($activity, $item);
 572                         }
 573
 574                         $item_id = Item::insert($item);
 575                         if ($item_id) {
 576                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 577                         } else {
 578                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 579                         }
 580
 581                         if ($item['uid'] == 0) {
 582                                 $stored = $item_id;
 583                         }
 584                 }
 585
 586                 // Store send a follow request for every reshare - but only when the item had been stored
 587                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 588                         $author = APContact::getByURL($item['owner-link'], false);
 589                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 590                         if ($author['type'] != 'Group') {
 591                                 Logger::log('Send follow request for ' . $item['uri'] . ' (' . $stored . ') to ' . $item['author-link'], Logger::DEBUG);
 592                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 593                         }
 594                 }
 595         }
 596
 597         /**
 598          * Store tags and mentions into the tag table
 599          *
 600          * @param integer $uriid
 601          * @param array $tags
 602          */
 603         private static function storeTags(int $uriid, array $tags = null)
 604         {
 605                 foreach ($tags as $tag) {
 606                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 607                                 continue;
 608                         }
 609
 610                         $hash = substr($tag['name'], 0, 1);
 611
 612                         if ($tag['type'] == 'Mention') {
 613                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 614                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 615                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 616                                         $tag['name'] = substr($tag['name'], 1);
 617                                 }
 618                                 $type = Tag::IMPLICIT_MENTION;
 619
 620                                 if (!empty($tag['href'])) {
 621                                         $apcontact = APContact::getByURL($tag['href']);
 622                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 623                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 624                                         }
 625                                 }
 626                         } elseif ($tag['type'] == 'Hashtag') {
 627                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 628                                         $tag['name'] = substr($tag['name'], 1);
 629                                 }
 630                                 $type = Tag::HASHTAG;
 631                         }
 632
 633                         if (empty($tag['name'])) {
 634                                 continue;
 635                         }
 636
 637                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 638                 }
 639         }
 640
 641         /**
 642          * Creates an mail post
 643          *
 644          * @param array $activity Activity data
 645          * @param array $item     item array
 646          * @return int|bool New mail table row id or false on error
 647          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 648          */
 649         private static function postMail($activity, $item)
 650         {
 651                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 652                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 653                         return false;
 654                 }
 655
 656                 Logger::info('Direct Message', $item);
 657
 658                 $msg = [];
 659                 $msg['uid'] = $item['uid'];
 660
 661                 $msg['contact-id'] = $item['contact-id'];
 662
 663                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 664                 $msg['from-name'] = $contact['name'];
 665                 $msg['from-url'] = $contact['url'];
 666                 $msg['from-photo'] = $contact['photo'];
 667
 668                 $msg['uri'] = $item['uri'];
 669                 $msg['created'] = $item['created'];
 670
 671                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 672                 if (DBA::isResult($parent)) {
 673                         $msg['parent-uri'] = $parent['parent-uri'];
 674                         $msg['title'] = $parent['title'];
 675                 } else {
 676                         $msg['parent-uri'] = $item['thr-parent'];
 677
 678                         if (!empty($item['title'])) {
 679                                 $msg['title'] = $item['title'];
 680                         } elseif (!empty($item['content-warning'])) {
 681                                 $msg['title'] = $item['content-warning'];
 682                         } else {
 683                                 // Trying to generate a title out of the body
 684                                 $title = $item['body'];
 685
 686                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 687                                         $title = $matches[3];
 688                                 }
 689
 690                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, 2, true), 0));
 691
 692                                 if (strlen($title) > 20) {
 693                                         $title = substr($title, 0, 20) . '...';
 694                                 }
 695
 696                                 $msg['title'] = $title;
 697                         }
 698                 }
 699                 $msg['body'] = $item['body'];
 700
 701                 return Mail::insert($msg);
 702         }
 703
 704         /**
 705          * Fetches missing posts
 706          *
 707          * @param string $url message URL
 708          * @param array $child activity array with the child of this message
 709          * @return string fetched message URL
 710          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 711          */
 712         public static function fetchMissingActivity($url, $child = [])
 713         {
 714                 if (!empty($child['receiver'])) {
 715                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 716                 } else {
 717                         $uid = 0;
 718                 }
 719
 720                 $object = ActivityPub::fetchContent($url, $uid);
 721                 if (empty($object)) {
 722                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 723                         return '';
 724                 }
 725
 726                 if (empty($object['id'])) {
 727                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 728                         return '';
 729                 }
 730
 731                 if (!empty($child['author'])) {
 732                         $actor = $child['author'];
 733                 } elseif (!empty($object['actor'])) {
 734                         $actor = $object['actor'];
 735                 } elseif (!empty($object['attributedTo'])) {
 736                         $actor = $object['attributedTo'];
 737                 } else {
 738                         // Shouldn't happen
 739                         $actor = '';
 740                 }
 741
 742                 if (!empty($object['published'])) {
 743                         $published = $object['published'];
 744                 } elseif (!empty($child['published'])) {
 745                         $published = $child['published'];
 746                 } else {
 747                         $published = DateTimeFormat::utcNow();
 748                 }
 749
 750                 $activity = [];
 751                 $activity['@context'] = $object['@context'];
 752                 unset($object['@context']);
 753                 $activity['id'] = $object['id'];
 754                 $activity['to'] = $object['to'] ?? [];
 755                 $activity['cc'] = $object['cc'] ?? [];
 756                 $activity['actor'] = $actor;
 757                 $activity['object'] = $object;
 758                 $activity['published'] = $published;
 759                 $activity['type'] = 'Create';
 760
 761                 $ldactivity = JsonLD::compact($activity);
 762
 763                 $ldactivity['thread-completion'] = true;
 764
 765                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity));
 766
 767                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 768
 769                 return $activity['id'];
 770         }
 771
 772         /**
 773          * perform a "follow" request
 774          *
 775          * @param array $activity
 776          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 777          * @throws \ImagickException
 778          */
 779         public static function followUser($activity)
 780         {
 781                 $uid = User::getIdForURL($activity['object_id']);
 782                 if (empty($uid)) {
 783                         return;
 784                 }
 785
 786                 $owner = User::getOwnerDataById($uid);
 787
 788                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 789                 if (!empty($cid)) {
 790                         self::switchContact($cid);
 791                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 792                         $contact = DBA::selectFirst('contact', [], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 793                 } else {
 794                         $contact = [];
 795                 }
 796
 797                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 798                         'author-link' => $activity['actor']];
 799
 800                 $note = Strings::escapeTags(trim($activity['content'] ?? ''));
 801
 802                 // Ensure that the contact has got the right network type
 803                 self::switchContact($item['author-id']);
 804
 805                 $result = Contact::addRelationship($owner, $contact, $item, false, $note);
 806                 if ($result === true) {
 807                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $item['author-id'], $owner['uid']);
 808                 }
 809
 810                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 811                 if (empty($cid)) {
 812                         return;
 813                 }
 814
 815                 if (empty($contact)) {
 816                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 817                 }
 818
 819                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 820         }
 821
 822         /**
 823          * Update the given profile
 824          *
 825          * @param array $activity
 826          * @throws \Exception
 827          */
 828         public static function updatePerson($activity)
 829         {
 830                 if (empty($activity['object_id'])) {
 831                         return;
 832                 }
 833
 834                 Logger::log('Updating profile for ' . $activity['object_id'], Logger::DEBUG);
 835                 Contact::updateFromProbeByURL($activity['object_id'], true);
 836         }
 837
 838         /**
 839          * Delete the given profile
 840          *
 841          * @param array $activity
 842          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 843          */
 844         public static function deletePerson($activity)
 845         {
 846                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 847                         Logger::log('Empty object id or actor.', Logger::DEBUG);
 848                         return;
 849                 }
 850
 851                 if ($activity['object_id'] != $activity['actor']) {
 852                         Logger::log('Object id does not match actor.', Logger::DEBUG);
 853                         return;
 854                 }
 855
 856                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 857                 while ($contact = DBA::fetch($contacts)) {
 858                         Contact::remove($contact['id']);
 859                 }
 860                 DBA::close($contacts);
 861
 862                 Logger::log('Deleted contact ' . $activity['object_id'], Logger::DEBUG);
 863         }
 864
 865         /**
 866          * Accept a follow request
 867          *
 868          * @param array $activity
 869          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 870          * @throws \ImagickException
 871          */
 872         public static function acceptFollowUser($activity)
 873         {
 874                 $uid = User::getIdForURL($activity['object_actor']);
 875                 if (empty($uid)) {
 876                         return;
 877                 }
 878
 879                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 880                 if (empty($cid)) {
 881                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 882                         return;
 883                 }
 884
 885                 self::switchContact($cid);
 886
 887                 $fields = ['pending' => false];
 888
 889                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
 890                 if ($contact['rel'] == Contact::FOLLOWER) {
 891                         $fields['rel'] = Contact::FRIEND;
 892                 }
 893
 894                 $condition = ['id' => $cid];
 895                 DBA::update('contact', $fields, $condition);
 896                 Logger::log('Accept contact request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 897         }
 898
 899         /**
 900          * Reject a follow request
 901          *
 902          * @param array $activity
 903          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 904          * @throws \ImagickException
 905          */
 906         public static function rejectFollowUser($activity)
 907         {
 908                 $uid = User::getIdForURL($activity['object_actor']);
 909                 if (empty($uid)) {
 910                         return;
 911                 }
 912
 913                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 914                 if (empty($cid)) {
 915                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 916                         return;
 917                 }
 918
 919                 self::switchContact($cid);
 920
 921                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
 922                         Contact::remove($cid);
 923                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . ' - contact had been removed.', Logger::DEBUG);
 924                 } else {
 925                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . '.', Logger::DEBUG);
 926                 }
 927         }
 928
 929         /**
 930          * Undo activity like "like" or "dislike"
 931          *
 932          * @param array $activity
 933          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 934          * @throws \ImagickException
 935          */
 936         public static function undoActivity($activity)
 937         {
 938                 if (empty($activity['object_id'])) {
 939                         return;
 940                 }
 941
 942                 if (empty($activity['object_actor'])) {
 943                         return;
 944                 }
 945
 946                 $author_id = Contact::getIdForURL($activity['object_actor']);
 947                 if (empty($author_id)) {
 948                         return;
 949                 }
 950
 951                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
 952         }
 953
 954         /**
 955          * Activity to remove a follower
 956          *
 957          * @param array $activity
 958          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 959          * @throws \ImagickException
 960          */
 961         public static function undoFollowUser($activity)
 962         {
 963                 $uid = User::getIdForURL($activity['object_object']);
 964                 if (empty($uid)) {
 965                         return;
 966                 }
 967
 968                 $owner = User::getOwnerDataById($uid);
 969
 970                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 971                 if (empty($cid)) {
 972                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 973                         return;
 974                 }
 975
 976                 self::switchContact($cid);
 977
 978                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
 979                 if (!DBA::isResult($contact)) {
 980                         return;
 981                 }
 982
 983                 Contact::removeFollower($owner, $contact);
 984                 Logger::log('Undo following request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 985         }
 986
 987         /**
 988          * Switches a contact to AP if needed
 989          *
 990          * @param integer $cid Contact ID
 991          * @throws \Exception
 992          */
 993         private static function switchContact($cid)
 994         {
 995                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
 996                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
 997                         return;
 998                 }
 999
1000                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1001                 Contact::updateFromProbe($cid);
1002         }
1003
1004         /**
1005          * Collects implicit mentions like:
1006          * - the author of the parent item
1007          * - all the mentioned conversants in the parent item
1008          *
1009          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1010          * @return array
1011          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1012          */
1013         private static function getImplicitMentionList(array $parent)
1014         {
1015                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1016                         return [];
1017                 }
1018
1019                 $parent_terms = Term::tagArrayFromItemId($parent['id'], [Term::MENTION, Term::IMPLICIT_MENTION]);
1020
1021                 $parent_author = Contact::getDetailsByURL($parent['author-link'], 0);
1022
1023                 $implicit_mentions = [];
1024                 if (empty($parent_author)) {
1025                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
1026                 } else {
1027                         $implicit_mentions[] = $parent_author['url'];
1028                         $implicit_mentions[] = $parent_author['nurl'];
1029                         $implicit_mentions[] = $parent_author['alias'];
1030                 }
1031
1032                 if (!empty($parent['alias'])) {
1033                         $implicit_mentions[] = $parent['alias'];
1034                 }
1035
1036                 foreach ($parent_terms as $term) {
1037                         $contact = Contact::getDetailsByURL($term['url'], 0);
1038                         if (!empty($contact)) {
1039                                 $implicit_mentions[] = $contact['url'];
1040                                 $implicit_mentions[] = $contact['nurl'];
1041                                 $implicit_mentions[] = $contact['alias'];
1042                         }
1043                 }
1044
1045                 return $implicit_mentions;
1046         }
1047
1048         /**
1049          * Strips from the body prepended implicit mentions
1050          *
1051          * @param string $body
1052          * @param array $potential_mentions
1053          * @return string
1054          */
1055         private static function removeImplicitMentionsFromBody($body, array $potential_mentions)
1056         {
1057                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1058                         return $body;
1059                 }
1060
1061                 $kept_mentions = [];
1062
1063                 // Extract one prepended mention at a time from the body
1064                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1065                         if (!in_array($matches[2], $potential_mentions)) {
1066                                 $kept_mentions[] = $matches[1];
1067                         }
1068
1069                         $body = $matches[3];
1070                 }
1071
1072                 // Re-appending the kept mentions to the body after extraction
1073                 $kept_mentions[] = $body;
1074
1075                 return implode('', $kept_mentions);
1076         }
1077
1078         private static function convertImplicitMentionsInTags($activity_tags, array $potential_mentions)
1079         {
1080                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1081                         return $activity_tags;
1082                 }
1083
1084                 foreach ($activity_tags as $index => $tag) {
1085                         if (in_array($tag['href'], $potential_mentions)) {
1086                                 $activity_tags[$index]['name'] = preg_replace(
1087                                         '/' . preg_quote(Term::TAG_CHARACTER[Term::MENTION], '/') . '/',
1088                                         Term::TAG_CHARACTER[Term::IMPLICIT_MENTION],
1089                                         $activity_tags[$index]['name'],
1090                                         1
1091                                 );
1092                         }
1093                 }
1094
1095                 return $activity_tags;
1096         }
1097 }