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