src/Protocol/ActivityPub/Transmitter.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2021, the Friendica project
   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\Feature;
  25 use Friendica\Content\Text\BBCode;
  26 use Friendica\Core\Cache\Duration;
  27 use Friendica\Core\Logger;
  28 use Friendica\Core\Protocol;
  29 use Friendica\Core\System;
  30 use Friendica\Database\DBA;
  31 use Friendica\DI;
  32 use Friendica\Model\APContact;
  33 use Friendica\Model\Contact;
  34 use Friendica\Model\Conversation;
  35 use Friendica\Model\GServer;
  36 use Friendica\Model\Item;
  37 use Friendica\Model\Photo;
  38 use Friendica\Model\Post;
  39 use Friendica\Model\Profile;
  40 use Friendica\Model\Tag;
  41 use Friendica\Model\User;
  42 use Friendica\Network\HTTPException;
  43 use Friendica\Protocol\Activity;
  44 use Friendica\Protocol\ActivityPub;
  45 use Friendica\Protocol\Relay;
  46 use Friendica\Util\DateTimeFormat;
  47 use Friendica\Util\HTTPSignature;
  48 use Friendica\Util\JsonLD;
  49 use Friendica\Util\LDSignature;
  50 use Friendica\Util\Map;
  51 use Friendica\Util\Network;
  52 use Friendica\Util\XML;
  53
  54 /**
  55  * ActivityPub Transmitter Protocol class
  56  *
  57  * To-Do:
  58  * @todo Undo Announce
  59  */
  60 class Transmitter
  61 {
  62         /**
  63          * Add relay servers to the list of inboxes
  64          *
  65          * @param array $inboxes
  66          * @return array inboxes with added relay servers
  67          */
  68         public static function addRelayServerInboxes(array $inboxes = [])
  69         {
  70                 foreach (Relay::getList(['inbox']) as $contact) {
  71                         $inboxes[$contact['inbox']] = $contact['inbox'];
  72                 }
  73
  74                 return $inboxes;
  75         }
  76
  77         /**
  78          * Add relay servers to the list of inboxes
  79          *
  80          * @param array $inboxes
  81          * @return array inboxes with added relay servers
  82          */
  83         public static function addRelayServerInboxesForItem(int $item_id, array $inboxes = [])
  84         {
  85                 $item = Post::selectFirst(['uid'], ['id' => $item_id]);
  86                 if (empty($item)) {
  87                         return $inboxes;
  88                 }
  89
  90                 $relays = Relay::getDirectRelayList($item_id);
  91                 if (empty($relays)) {
  92                         return $inboxes;
  93                 }
  94
  95                 foreach ($relays as $relay) {
  96                         $contact = Contact::getByURLForUser($relay['url'], $item['uid'], false, ['id']);
  97                         $inboxes[$relay['batch']][] = $contact['id'] ?? 0;
  98                 }
  99                 return $inboxes;
 100         }
 101
 102         /**
 103          * Subscribe to a relay
 104          *
 105          * @param string $url Subscribe actor url
 106          * @return bool success
 107          */
 108         public static function sendRelayFollow(string $url)
 109         {
 110                 $contact = Contact::getByURL($url);
 111                 if (empty($contact)) {
 112                         return false;
 113                 }
 114
 115                 $activity_id = ActivityPub\Transmitter::activityIDFromContact($contact['id']);
 116                 $success = ActivityPub\Transmitter::sendActivity('Follow', $url, 0, $activity_id);
 117                 if ($success) {
 118                         Contact::update(['rel' => Contact::FRIEND], ['id' => $contact['id']]);
 119                 }
 120
 121                 return $success;
 122         }
 123
 124         /**
 125          * Unsubscribe from a relay
 126          *
 127          * @param string $url   Subscribe actor url
 128          * @param bool   $force Set the relay status as non follower even if unsubscribe hadn't worked
 129          * @return bool success
 130          */
 131         public static function sendRelayUndoFollow(string $url, bool $force = false)
 132         {
 133                 $contact = Contact::getByURL($url);
 134                 if (empty($contact)) {
 135                         return false;
 136                 }
 137
 138                 $success = self::sendContactUndo($url, $contact['id'], 0);
 139                 if ($success || $force) {
 140                         Contact::update(['rel' => Contact::NOTHING], ['id' => $contact['id']]);
 141                 }
 142
 143                 return $success;
 144         }
 145
 146         /**
 147          * Collects a list of contacts of the given owner
 148          *
 149          * @param array     $owner  Owner array
 150          * @param int|array $rel    The relevant value(s) contact.rel should match
 151          * @param string    $module The name of the relevant AP endpoint module (followers|following)
 152          * @param integer   $page   Page number
 153          *
 154          * @return array of owners
 155          * @throws \Exception
 156          */
 157         public static function getContacts($owner, $rel, $module, $page = null)
 158         {
 159                 $parameters = [
 160                         'rel' => $rel,
 161                         'uid' => $owner['uid'],
 162                         'self' => false,
 163                         'deleted' => false,
 164                         'hidden' => false,
 165                         'archive' => false,
 166                         'pending' => false,
 167                         'blocked' => false,
 168                 ];
 169                 $condition = DBA::buildCondition($parameters);
 170
 171                 $sql = "SELECT COUNT(*) as `count`
 172                         FROM `contact`
 173                         JOIN `apcontact` ON `apcontact`.`url` = `contact`.`url`
 174                         " . $condition;
 175
 176                 $contacts = DBA::fetchFirst($sql, ...$parameters);
 177
 178                 $modulePath = '/' . $module . '/';
 179
 180                 $data = ['@context' => ActivityPub::CONTEXT];
 181                 $data['id'] = DI::baseUrl() . $modulePath . $owner['nickname'];
 182                 $data['type'] = 'OrderedCollection';
 183                 $data['totalItems'] = $contacts['count'];
 184
 185                 // When we hide our friends we will only show the pure number but don't allow more.
 186                 $profile = Profile::getByUID($owner['uid']);
 187                 if (!empty($profile['hide-friends'])) {
 188                         return $data;
 189                 }
 190
 191                 if (empty($page)) {
 192                         $data['first'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=1';
 193                 } else {
 194                         $data['type'] = 'OrderedCollectionPage';
 195                         $list = [];
 196
 197                         $sql = "SELECT `contact`.`url`
 198                                 FROM `contact`
 199                                 JOIN `apcontact` ON `apcontact`.`url` = `contact`.`url`
 200                                 " . $condition . "
 201                                 LIMIT ?, ?";
 202
 203                         $parameters[] = ($page - 1) * 100;
 204                         $parameters[] = 100;
 205
 206                         $contacts = DBA::p($sql, ...$parameters);
 207                         while ($contact = DBA::fetch($contacts)) {
 208                                 $list[] = $contact['url'];
 209                         }
 210                         DBA::close($contacts);
 211
 212                         if (!empty($list)) {
 213                                 $data['next'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=' . ($page + 1);
 214                         }
 215
 216                         $data['partOf'] = DI::baseUrl() . $modulePath . $owner['nickname'];
 217
 218                         $data['orderedItems'] = $list;
 219                 }
 220
 221                 return $data;
 222         }
 223
 224         /**
 225          * Public posts for the given owner
 226          *
 227          * @param array   $owner     Owner array
 228          * @param integer $page      Page number
 229          * @param string  $requester URL of requesting account
 230          *
 231          * @return array of posts
 232          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 233          * @throws \ImagickException
 234          */
 235         public static function getOutbox($owner, $page = null, $requester = '')
 236         {
 237                 $condition = ['private' => [Item::PUBLIC, Item::UNLISTED]];
 238
 239                 if (!empty($requester)) {
 240                         $requester_id = Contact::getIdForURL($requester, $owner['uid']);
 241                         if (!empty($requester_id)) {
 242                                 $permissionSets = DI::permissionSet()->selectByContactId($requester_id, $owner['uid']);
 243                                 if (!empty($permissionSets)) {
 244                                         $condition = ['psid' => array_merge($permissionSets->column('id'),
 245                                                         [DI::permissionSet()->getIdFromACL($owner['uid'], '', '', '', '')])];
 246                                 }
 247                         }
 248                 }
 249
 250                 $condition = array_merge($condition,
 251                         ['uid'           => $owner['uid'],
 252                         'author-id'      => Contact::getIdForURL($owner['url'], 0, false),
 253                         'gravity'        => [GRAVITY_PARENT, GRAVITY_COMMENT],
 254                         'network'        => Protocol::FEDERATED,
 255                         'parent-network' => Protocol::FEDERATED,
 256                         'origin'         => true,
 257                         'deleted'        => false,
 258                         'visible'        => true]);
 259
 260                 $count = Post::count($condition);
 261
 262                 $data = ['@context' => ActivityPub::CONTEXT];
 263                 $data['id'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
 264                 $data['type'] = 'OrderedCollection';
 265                 $data['totalItems'] = $count;
 266
 267                 if (empty($page)) {
 268                         $data['first'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=1';
 269                 } else {
 270                         $data['type'] = 'OrderedCollectionPage';
 271                         $list = [];
 272
 273                         $items = Post::select(['id'], $condition, ['limit' => [($page - 1) * 20, 20], 'order' => ['created' => true]]);
 274                         while ($item = Post::fetch($items)) {
 275                                 $activity = self::createActivityFromItem($item['id'], true);
 276                                 $activity['type'] = $activity['type'] == 'Update' ? 'Create' : $activity['type'];
 277
 278                                 // Only list "Create" activity objects here, no reshares
 279                                 if (!empty($activity['object']) && ($activity['type'] == 'Create')) {
 280                                         $list[] = $activity['object'];
 281                                 }
 282                         }
 283                         DBA::close($items);
 284
 285                         if (!empty($list)) {
 286                                 $data['next'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=' . ($page + 1);
 287                         }
 288
 289                         $data['partOf'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
 290
 291                         $data['orderedItems'] = $list;
 292                 }
 293
 294                 return $data;
 295         }
 296
 297         /**
 298          * Return the service array containing information the used software and it's url
 299          *
 300          * @return array with service data
 301          */
 302         private static function getService()
 303         {
 304                 return ['type' => 'Service',
 305                         'name' =>  FRIENDICA_PLATFORM . " '" . FRIENDICA_CODENAME . "' " . FRIENDICA_VERSION . '-' . DB_UPDATE_VERSION,
 306                         'url' => DI::baseUrl()->get()];
 307         }
 308
 309         /**
 310          * Return the ActivityPub profile of the given user
 311          *
 312          * @param int $uid User ID
 313          * @return array with profile data
 314          * @throws HTTPException\NotFoundException
 315          * @throws HTTPException\InternalServerErrorException
 316          */
 317         public static function getProfile(int $uid): array
 318         {
 319                 $owner = User::getOwnerDataById($uid);
 320                 if (!isset($owner['id'])) {
 321                         DI::logger()->error('Unable to find owner data for uid', ['uid' => $uid, 'callstack' => System::callstack(20)]);
 322                         throw new HTTPException\NotFoundException('User not found.');
 323                 }
 324
 325                 $data = ['@context' => ActivityPub::CONTEXT];
 326                 $data['id'] = $owner['url'];
 327
 328                 if (!empty($owner['guid'])) {
 329                         $data['diaspora:guid'] = $owner['guid'];
 330                 }
 331
 332                 $data['type'] = ActivityPub::ACCOUNT_TYPES[$owner['account-type']];
 333
 334                 if ($uid != 0) {
 335                         $data['following'] = DI::baseUrl() . '/following/' . $owner['nick'];
 336                         $data['followers'] = DI::baseUrl() . '/followers/' . $owner['nick'];
 337                         $data['inbox'] = DI::baseUrl() . '/inbox/' . $owner['nick'];
 338                         $data['outbox'] = DI::baseUrl() . '/outbox/' . $owner['nick'];
 339                 } else {
 340                         $data['inbox'] = DI::baseUrl() . '/friendica/inbox';
 341                 }
 342
 343                 $data['preferredUsername'] = $owner['nick'];
 344                 $data['name'] = $owner['name'];
 345
 346                 if (!empty($owner['country-name'] . $owner['region'] . $owner['locality'])) {
 347                         $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $owner['country-name'],
 348                                 'vcard:region' => $owner['region'], 'vcard:locality' => $owner['locality']];
 349                 }
 350
 351                 if (!empty($owner['about'])) {
 352                         $data['summary'] = BBCode::convertForUriId($owner['uri-id'] ?? 0, $owner['about'], BBCode::EXTERNAL);
 353                 }
 354
 355                 if (!empty($owner['xmpp']) || !empty($owner['matrix'])) {
 356                         $data['vcard:hasInstantMessage'] = [];
 357
 358                         if (!empty($owner['xmpp'])) {
 359                                 $data['vcard:hasInstantMessage'][] = 'xmpp:' . $owner['xmpp'];
 360                         }
 361                         if (!empty($owner['matrix'])) {
 362                                 $data['vcard:hasInstantMessage'][] = 'matrix:' . $owner['matrix'];
 363                         }
 364                 }
 365
 366                 $data['url'] = $owner['url'];
 367                 $data['manuallyApprovesFollowers'] = in_array($owner['page-flags'], [User::PAGE_FLAGS_NORMAL, User::PAGE_FLAGS_PRVGROUP]);
 368                 $data['discoverable'] = (bool)$owner['net-publish'];
 369                 $data['publicKey'] = ['id' => $owner['url'] . '#main-key',
 370                         'owner' => $owner['url'],
 371                         'publicKeyPem' => $owner['pubkey']];
 372                 $data['endpoints'] = ['sharedInbox' => DI::baseUrl() . '/inbox'];
 373                 $data['icon'] = ['type' => 'Image', 'url' => Contact::getAvatarUrlForId($owner['id'], '', $owner['updated'])];
 374
 375                 $resourceid = Photo::ridFromURI($owner['photo']);
 376                 if (!empty($resourceid)) {
 377                         $photo = Photo::selectFirst(['type'], ["resource-id" => $resourceid]);
 378                         if (!empty($photo['type'])) {
 379                                 $data['icon']['mediaType'] = $photo['type'];
 380                         }
 381                 }
 382
 383                 if (!empty($owner['header'])) {
 384                         $data['image'] = ['type' => 'Image', 'url' => Contact::getHeaderUrlForId($owner['id'], '', $owner['updated'])];
 385
 386                         $resourceid = Photo::ridFromURI($owner['header']);
 387                         if (!empty($resourceid)) {
 388                                 $photo = Photo::selectFirst(['type'], ["resource-id" => $resourceid]);
 389                                 if (!empty($photo['type'])) {
 390                                         $data['image']['mediaType'] = $photo['type'];
 391                                 }
 392                         }
 393                 }
 394
 395                 $data['generator'] = self::getService();
 396
 397                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
 398                 return $data;
 399         }
 400
 401         /**
 402          * @param string $username
 403          * @return array
 404          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 405          */
 406         public static function getDeletedUser($username)
 407         {
 408                 return [
 409                         '@context' => ActivityPub::CONTEXT,
 410                         'id' => DI::baseUrl() . '/profile/' . $username,
 411                         'type' => 'Tombstone',
 412                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 413                         'updated' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 414                         'deleted' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 415                 ];
 416         }
 417
 418         /**
 419          * Returns an array with permissions of a given item array
 420          *
 421          * @param array $item
 422          *
 423          * @return array with permissions
 424          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 425          * @throws \ImagickException
 426          */
 427         private static function fetchPermissionBlockFromConversation($item)
 428         {
 429                 if (empty($item['thr-parent'])) {
 430                         return [];
 431                 }
 432
 433                 $condition = ['item-uri' => $item['thr-parent'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
 434                 $conversation = DBA::selectFirst('conversation', ['source'], $condition);
 435                 if (!DBA::isResult($conversation)) {
 436                         return [];
 437                 }
 438
 439                 $activity = json_decode($conversation['source'], true);
 440
 441                 $actor = JsonLD::fetchElement($activity, 'actor', 'id');
 442                 if (!empty($actor)) {
 443                         $permissions['to'][] = $actor;
 444                         $profile = APContact::getByURL($actor);
 445                 } else {
 446                         $profile = [];
 447                 }
 448
 449                 $item_profile = APContact::getByURL($item['author-link']);
 450                 $exclude[] = $item['author-link'];
 451
 452                 if ($item['gravity'] == GRAVITY_PARENT) {
 453                         $exclude[] = $item['owner-link'];
 454                 }
 455
 456                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 457                         if (empty($activity[$element])) {
 458                                 continue;
 459                         }
 460                         if (is_string($activity[$element])) {
 461                                 $activity[$element] = [$activity[$element]];
 462                         }
 463
 464                         foreach ($activity[$element] as $receiver) {
 465                                 if (empty($receiver)) {
 466                                         continue;
 467                                 }
 468
 469                                 if (!empty($profile['followers']) && $receiver == $profile['followers'] && !empty($item_profile['followers'])) {
 470                                         $permissions[$element][] = $item_profile['followers'];
 471                                 } elseif (!in_array($receiver, $exclude)) {
 472                                         $permissions[$element][] = $receiver;
 473                                 }
 474                         }
 475                 }
 476                 return $permissions;
 477         }
 478
 479         /**
 480          * Check if the given item id is from ActivityPub
 481          *
 482          * @param integer $item_id
 483          * @return boolean "true" if the post is from ActivityPub
 484          */
 485         private static function isAPPost(int $item_id)
 486         {
 487                 if (empty($item_id)) {
 488                         return false;
 489                 }
 490
 491                 return Post::exists(['id' => $item_id, 'network' => Protocol::ACTIVITYPUB]);
 492         }
 493
 494         /**
 495          * Creates an array of permissions from an item thread
 496          *
 497          * @param array   $item       Item array
 498          * @param boolean $blindcopy  addressing via "bcc" or "cc"?
 499          * @param integer $last_id    Last item id for adding receivers
 500          * @param boolean $forum_mode "true" means that we are sending content to a forum
 501          *
 502          * @return array with permission data
 503          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 504          * @throws \ImagickException
 505          */
 506         private static function createPermissionBlockForItem($item, $blindcopy, $last_id = 0, $forum_mode = false)
 507         {
 508                 if ($last_id == 0) {
 509                         $last_id = $item['id'];
 510                 }
 511
 512                 $always_bcc = false;
 513
 514                 // Check if we should always deliver our stuff via BCC
 515                 if (!empty($item['uid'])) {
 516                         $profile = User::getOwnerDataById($item['uid']);
 517                         if (!empty($profile)) {
 518                                 $always_bcc = $profile['hide-friends'];
 519                         }
 520                 }
 521
 522                 if (DI::config()->get('system', 'ap_always_bcc')) {
 523                         $always_bcc = true;
 524                 }
 525
 526                 if (self::isAnnounce($item) || DI::config()->get('debug', 'total_ap_delivery') || self::isAPPost($last_id)) {
 527                         // Will be activated in a later step
 528                         $networks = Protocol::FEDERATED;
 529                 } else {
 530                         // For now only send to these contacts:
 531                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 532                 }
 533
 534                 $data = ['to' => [], 'cc' => [], 'bcc' => []];
 535
 536                 if ($item['gravity'] == GRAVITY_PARENT) {
 537                         $actor_profile = APContact::getByURL($item['owner-link']);
 538                 } else {
 539                         $actor_profile = APContact::getByURL($item['author-link']);
 540                 }
 541
 542                 $exclusive = false;
 543
 544                 $terms = Tag::getByURIId($item['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
 545
 546                 if ($item['private'] != Item::PRIVATE) {
 547                         // Directly mention the original author upon a quoted reshare.
 548                         // Else just ensure that the original author receives the reshare.
 549                         $announce = self::getAnnounceArray($item);
 550                         if (!empty($announce['comment'])) {
 551                                 $data['to'][] = $announce['actor']['url'];
 552                         } elseif (!empty($announce)) {
 553                                 $data['cc'][] = $announce['actor']['url'];
 554                         }
 555
 556                         $data = array_merge($data, self::fetchPermissionBlockFromConversation($item));
 557
 558                         // Check if the item is completely public or unlisted
 559                         if ($item['private'] == Item::PUBLIC) {
 560                                 $data['to'][] = ActivityPub::PUBLIC_COLLECTION;
 561                         } else {
 562                                 $data['cc'][] = ActivityPub::PUBLIC_COLLECTION;
 563                         }
 564
 565                         foreach ($terms as $term) {
 566                                 $profile = APContact::getByURL($term['url'], false);
 567                                 if (!empty($profile)) {
 568                                         if ($term['type'] == Tag::EXCLUSIVE_MENTION) {
 569                                                 $exclusive = true;
 570                                                 if (!empty($profile['followers']) && ($profile['type'] == 'Group')) {
 571                                                         $data['cc'][] = $profile['followers'];
 572                                                 }
 573                                         }
 574                                         $data['to'][] = $profile['url'];
 575                                 }
 576                         }
 577                 } else {
 578                         $receiver_list = Item::enumeratePermissions($item, true);
 579
 580                         foreach ($terms as $term) {
 581                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 582                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 583                                         $contact = DBA::selectFirst('contact', ['url', 'network', 'protocol', 'gsid'], ['id' => $cid, 'network' => Protocol::FEDERATED]);
 584                                         if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
 585                                                 continue;
 586                                         }
 587
 588                                         if (!empty($profile = APContact::getByURL($contact['url'], false))) {
 589                                                 $data['to'][] = $profile['url'];
 590                                         }
 591                                 }
 592                         }
 593
 594                         foreach ($receiver_list as $receiver) {
 595                                 $contact = DBA::selectFirst('contact', ['url', 'hidden', 'network', 'protocol', 'gsid'], ['id' => $receiver, 'network' => Protocol::FEDERATED]);
 596                                 if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
 597                                         continue;
 598                                 }
 599
 600                                 if (!empty($profile = APContact::getByURL($contact['url'], false))) {
 601                                         if ($contact['hidden'] || $always_bcc) {
 602                                                 $data['bcc'][] = $profile['url'];
 603                                         } else {
 604                                                 $data['cc'][] = $profile['url'];
 605                                         }
 606                                 }
 607                         }
 608                 }
 609
 610                 if (!empty($item['parent'])) {
 611                         $parents = Post::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']]);
 612                         while ($parent = Post::fetch($parents)) {
 613                                 if ($parent['gravity'] == GRAVITY_PARENT) {
 614                                         $profile = APContact::getByURL($parent['owner-link'], false);
 615                                         if (!empty($profile)) {
 616                                                 if ($item['gravity'] != GRAVITY_PARENT) {
 617                                                         // Comments to forums are directed to the forum
 618                                                         // But comments to forums aren't directed to the followers collection
 619                                                         // This rule is only valid when the actor isn't the forum.
 620                                                         // The forum needs to transmit their content to their followers.
 621                                                         if (($profile['type'] == 'Group') && ($profile['url'] != ($actor_profile['url'] ?? ''))) {
 622                                                                 $data['to'][] = $profile['url'];
 623                                                         } else {
 624                                                                 $data['cc'][] = $profile['url'];
 625                                                                 if (($item['private'] != Item::PRIVATE) && !empty($actor_profile['followers'])) {
 626                                                                         $data['cc'][] = $actor_profile['followers'];
 627                                                                 }
 628                                                         }
 629                                                 } elseif (!$exclusive) {
 630                                                         // Public thread parent post always are directed to the followers.
 631                                                         // This mustn't be done by posts that are directed to forum servers via the exclusive mention.
 632                                                         // But possibly in that case we could add the "followers" collection of the forum to the message.
 633                                                         if (($item['private'] != Item::PRIVATE) && !$forum_mode) {
 634                                                                 $data['cc'][] = $actor_profile['followers'];
 635                                                         }
 636                                                 }
 637                                         }
 638                                 }
 639
 640                                 // Don't include data from future posts
 641                                 if ($parent['id'] >= $last_id) {
 642                                         continue;
 643                                 }
 644
 645                                 $profile = APContact::getByURL($parent['author-link'], false);
 646                                 if (!empty($profile)) {
 647                                         if (($profile['type'] == 'Group') || ($parent['uri'] == $item['thr-parent'])) {
 648                                                 $data['to'][] = $profile['url'];
 649                                         } else {
 650                                                 $data['cc'][] = $profile['url'];
 651                                         }
 652                                 }
 653                         }
 654                         DBA::close($parents);
 655                 }
 656
 657                 $data['to'] = array_unique($data['to']);
 658                 $data['cc'] = array_unique($data['cc']);
 659                 $data['bcc'] = array_unique($data['bcc']);
 660
 661                 if (($key = array_search($item['author-link'], $data['to'])) !== false) {
 662                         unset($data['to'][$key]);
 663                 }
 664
 665                 if (($key = array_search($item['author-link'], $data['cc'])) !== false) {
 666                         unset($data['cc'][$key]);
 667                 }
 668
 669                 if (($key = array_search($item['author-link'], $data['bcc'])) !== false) {
 670                         unset($data['bcc'][$key]);
 671                 }
 672
 673                 foreach ($data['to'] as $to) {
 674                         if (($key = array_search($to, $data['cc'])) !== false) {
 675                                 unset($data['cc'][$key]);
 676                         }
 677
 678                         if (($key = array_search($to, $data['bcc'])) !== false) {
 679                                 unset($data['bcc'][$key]);
 680                         }
 681                 }
 682
 683                 foreach ($data['cc'] as $cc) {
 684                         if (($key = array_search($cc, $data['bcc'])) !== false) {
 685                                 unset($data['bcc'][$key]);
 686                         }
 687                 }
 688
 689                 $receivers = ['to' => array_values($data['to']), 'cc' => array_values($data['cc']), 'bcc' => array_values($data['bcc'])];
 690
 691                 if (!$blindcopy) {
 692                         unset($receivers['bcc']);
 693                 }
 694
 695                 return $receivers;
 696         }
 697
 698         /**
 699          * Check if an inbox is archived
 700          *
 701          * @param string $url Inbox url
 702          *
 703          * @return boolean "true" if inbox is archived
 704          */
 705         public static function archivedInbox($url)
 706         {
 707                 return DBA::exists('inbox-status', ['url' => $url, 'archive' => true]);
 708         }
 709
 710         /**
 711          * Check if a given contact should be delivered via AP
 712          *
 713          * @param array $contact
 714          * @param array $networks
 715          * @return bool
 716          * @throws Exception
 717          */
 718         private static function isAPContact(array $contact, array $networks)
 719         {
 720                 if (in_array($contact['network'], $networks) || ($contact['protocol'] == Protocol::ACTIVITYPUB)) {
 721                         return true;
 722                 }
 723
 724                 return GServer::getProtocol($contact['gsid'] ?? 0) == Post\DeliveryData::ACTIVITYPUB;
 725         }
 726
 727         /**
 728          * Fetches a list of inboxes of followers of a given user
 729          *
 730          * @param integer $uid      User ID
 731          * @param boolean $personal fetch personal inboxes
 732          * @param boolean $all_ap   Retrieve all AP enabled inboxes
 733          *
 734          * @return array of follower inboxes
 735          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 736          * @throws \ImagickException
 737          */
 738         public static function fetchTargetInboxesforUser($uid, $personal = false, bool $all_ap = false)
 739         {
 740                 $inboxes = [];
 741
 742                 $isforum = false;
 743
 744                 if (!empty($item['uid'])) {
 745                         $profile = User::getOwnerDataById($item['uid']);
 746                         if (!empty($profile)) {
 747                                 $isforum = $profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY;
 748                         }
 749                 }
 750
 751                 if (DI::config()->get('debug', 'total_ap_delivery') || $all_ap) {
 752                         // Will be activated in a later step
 753                         $networks = Protocol::FEDERATED;
 754                 } else {
 755                         // For now only send to these contacts:
 756                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 757                 }
 758
 759                 $condition = ['uid' => $uid, 'archive' => false, 'pending' => false, 'blocked' => false, 'network' => Protocol::FEDERATED];
 760
 761                 if (!empty($uid)) {
 762                         $condition['rel'] = [Contact::FOLLOWER, Contact::FRIEND];
 763                 }
 764
 765                 $contacts = DBA::select('contact', ['id', 'url', 'network', 'protocol', 'gsid'], $condition);
 766                 while ($contact = DBA::fetch($contacts)) {
 767                         if (!self::isAPContact($contact, $networks)) {
 768                                 continue;
 769                         }
 770
 771                         if ($isforum && ($contact['network'] == Protocol::DFRN)) {
 772                                 continue;
 773                         }
 774
 775                         if (Network::isUrlBlocked($contact['url'])) {
 776                                 continue;
 777                         }
 778
 779                         $profile = APContact::getByURL($contact['url'], false);
 780                         if (!empty($profile)) {
 781                                 if (empty($profile['sharedinbox']) || $personal || Contact::isLocal($contact['url'])) {
 782                                         $target = $profile['inbox'];
 783                                 } else {
 784                                         $target = $profile['sharedinbox'];
 785                                 }
 786                                 if (!self::archivedInbox($target)) {
 787                                         $inboxes[$target][] = $contact['id'];
 788                                 }
 789                         }
 790                 }
 791                 DBA::close($contacts);
 792
 793                 return $inboxes;
 794         }
 795
 796         /**
 797          * Fetches an array of inboxes for the given item and user
 798          *
 799          * @param array   $item       Item array
 800          * @param integer $uid        User ID
 801          * @param boolean $personal   fetch personal inboxes
 802          * @param integer $last_id    Last item id for adding receivers
 803          * @param boolean $forum_mode "true" means that we are sending content to a forum
 804          * @return array with inboxes
 805          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 806          * @throws \ImagickException
 807          */
 808         public static function fetchTargetInboxes($item, $uid, $personal = false, $last_id = 0, $forum_mode = false)
 809         {
 810                 $permissions = self::createPermissionBlockForItem($item, true, $last_id, $forum_mode);
 811                 if (empty($permissions)) {
 812                         return [];
 813                 }
 814
 815                 $inboxes = [];
 816
 817                 if ($item['gravity'] == GRAVITY_ACTIVITY) {
 818                         $item_profile = APContact::getByURL($item['author-link'], false);
 819                 } else {
 820                         $item_profile = APContact::getByURL($item['owner-link'], false);
 821                 }
 822
 823                 if (empty($item_profile)) {
 824                         return [];
 825                 }
 826
 827                 $profile_uid = User::getIdForURL($item_profile['url']);
 828
 829                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 830                         if (empty($permissions[$element])) {
 831                                 continue;
 832                         }
 833
 834                         $blindcopy = in_array($element, ['bto', 'bcc']);
 835
 836                         foreach ($permissions[$element] as $receiver) {
 837                                 if (empty($receiver) || Network::isUrlBlocked($receiver)) {
 838                                         continue;
 839                                 }
 840
 841                                 if ($item_profile && ($receiver == $item_profile['followers']) && ($uid == $profile_uid)) {
 842                                         $inboxes = array_merge($inboxes, self::fetchTargetInboxesforUser($uid, $personal, self::isAPPost($last_id)));
 843                                 } else {
 844                                         $profile = APContact::getByURL($receiver, false);
 845                                         if (!empty($profile)) {
 846                                                 $contact = Contact::getByURLForUser($receiver, $uid, false, ['id']);
 847
 848                                                 if (empty($profile['sharedinbox']) || $personal || $blindcopy || Contact::isLocal($receiver)) {
 849                                                         $target = $profile['inbox'];
 850                                                 } else {
 851                                                         $target = $profile['sharedinbox'];
 852                                                 }
 853                                                 if (!self::archivedInbox($target)) {
 854                                                         $inboxes[$target][] = $contact['id'] ?? 0;
 855                                                 }
 856                                         }
 857                                 }
 858                         }
 859                 }
 860
 861                 return $inboxes;
 862         }
 863
 864         /**
 865          * Creates an array in the structure of the item table for a given mail id
 866          *
 867          * @param integer $mail_id
 868          *
 869          * @return array
 870          * @throws \Exception
 871          */
 872         public static function ItemArrayFromMail($mail_id, $use_title = false)
 873         {
 874                 $mail = DBA::selectFirst('mail', [], ['id' => $mail_id]);
 875                 if (!DBA::isResult($mail)) {
 876                         return [];
 877                 }
 878
 879                 $reply = DBA::selectFirst('mail', ['uri', 'uri-id', 'from-url'], ['parent-uri' => $mail['parent-uri'], 'reply' => false]);
 880                 if (!DBA::isResult($reply)) {
 881                         $reply = $mail;
 882                 }
 883
 884                 // Making the post more compatible for Mastodon by:
 885                 // - Making it a note and not an article (no title)
 886                 // - Moving the title into the "summary" field that is used as a "content warning"
 887
 888                 if (!$use_title) {
 889                         $mail['body']         = '[abstract]' . $mail['title'] . "[/abstract]\n" . $mail['body'];
 890                         $mail['title']        = '';
 891                 }
 892
 893                 $mail['author-link']      = $mail['owner-link'] = $mail['from-url'];
 894                 $mail['owner-id']         = $mail['author-id'];
 895                 $mail['allow_cid']        = '<'.$mail['contact-id'].'>';
 896                 $mail['allow_gid']        = '';
 897                 $mail['deny_cid']         = '';
 898                 $mail['deny_gid']         = '';
 899                 $mail['private']          = Item::PRIVATE;
 900                 $mail['deleted']          = false;
 901                 $mail['edited']           = $mail['created'];
 902                 $mail['plink']            = DI::baseUrl() . '/message/' . $mail['id'];
 903                 $mail['parent-uri']       = $reply['uri'];
 904                 $mail['parent-uri-id']    = $reply['uri-id'];
 905                 $mail['parent-author-id'] = Contact::getIdForURL($reply['from-url'], 0, false);
 906                 $mail['gravity']          = ($mail['reply'] ? GRAVITY_COMMENT: GRAVITY_PARENT);
 907                 $mail['event-type']       = '';
 908                 $mail['language']         = '';
 909                 $mail['parent']           = 0;
 910
 911                 return $mail;
 912         }
 913
 914         /**
 915          * Creates an activity array for a given mail id
 916          *
 917          * @param integer $mail_id
 918          * @param boolean $object_mode Is the activity item is used inside another object?
 919          *
 920          * @return array of activity
 921          * @throws \Exception
 922          */
 923         public static function createActivityFromMail($mail_id, $object_mode = false)
 924         {
 925                 $mail = self::ItemArrayFromMail($mail_id);
 926                 if (empty($mail)) {
 927                         return [];
 928                 }
 929                 $object = self::createNote($mail);
 930
 931                 if (!$object_mode) {
 932                         $data = ['@context' => ActivityPub::CONTEXT];
 933                 } else {
 934                         $data = [];
 935                 }
 936
 937                 $data['id'] = $mail['uri'] . '/Create';
 938                 $data['type'] = 'Create';
 939                 $data['actor'] = $mail['author-link'];
 940                 $data['published'] = DateTimeFormat::utc($mail['created'] . '+00:00', DateTimeFormat::ATOM);
 941                 $data['instrument'] = self::getService();
 942                 $data = array_merge($data, self::createPermissionBlockForItem($mail, true));
 943
 944                 if (empty($data['to']) && !empty($data['cc'])) {
 945                         $data['to'] = $data['cc'];
 946                 }
 947
 948                 if (empty($data['to']) && !empty($data['bcc'])) {
 949                         $data['to'] = $data['bcc'];
 950                 }
 951
 952                 unset($data['cc']);
 953                 unset($data['bcc']);
 954
 955                 $object['to'] = $data['to'];
 956                 $object['tag'] = [['type' => 'Mention', 'href' => $object['to'][0], 'name' => '']];
 957
 958                 unset($object['cc']);
 959                 unset($object['bcc']);
 960
 961                 $data['directMessage'] = true;
 962
 963                 $data['object'] = $object;
 964
 965                 $owner = User::getOwnerDataById($mail['uid']);
 966
 967                 if (!$object_mode && !empty($owner)) {
 968                         return LDSignature::sign($data, $owner);
 969                 } else {
 970                         return $data;
 971                 }
 972         }
 973
 974         /**
 975          * Returns the activity type of a given item
 976          *
 977          * @param array $item
 978          *
 979          * @return string with activity type
 980          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 981          * @throws \ImagickException
 982          */
 983         private static function getTypeOfItem($item)
 984         {
 985                 $reshared = false;
 986
 987                 // Only check for a reshare, if it is a real reshare and no quoted reshare
 988                 if (strpos($item['body'], "[share") === 0) {
 989                         $announce = self::getAnnounceArray($item);
 990                         $reshared = !empty($announce);
 991                 }
 992
 993                 if ($reshared) {
 994                         $type = 'Announce';
 995                 } elseif ($item['verb'] == Activity::POST) {
 996                         if ($item['created'] == $item['edited']) {
 997                                 $type = 'Create';
 998                         } else {
 999                                 $type = 'Update';
1000                         }
1001                 } elseif ($item['verb'] == Activity::LIKE) {
1002                         $type = 'Like';
1003                 } elseif ($item['verb'] == Activity::DISLIKE) {
1004                         $type = 'Dislike';
1005                 } elseif ($item['verb'] == Activity::ATTEND) {
1006                         $type = 'Accept';
1007                 } elseif ($item['verb'] == Activity::ATTENDNO) {
1008                         $type = 'Reject';
1009                 } elseif ($item['verb'] == Activity::ATTENDMAYBE) {
1010                         $type = 'TentativeAccept';
1011                 } elseif ($item['verb'] == Activity::FOLLOW) {
1012                         $type = 'Follow';
1013                 } elseif ($item['verb'] == Activity::TAG) {
1014                         $type = 'Add';
1015                 } elseif ($item['verb'] == Activity::ANNOUNCE) {
1016                         $type = 'Announce';
1017                 } else {
1018                         $type = '';
1019                 }
1020
1021                 return $type;
1022         }
1023
1024         /**
1025          * Creates the activity or fetches it from the cache
1026          *
1027          * @param integer $item_id
1028          * @param boolean $force Force new cache entry
1029          *
1030          * @return array with the activity
1031          * @throws \Exception
1032          */
1033         public static function createCachedActivityFromItem($item_id, $force = false)
1034         {
1035                 $cachekey = 'APDelivery:createActivity:' . $item_id;
1036
1037                 if (!$force) {
1038                         $data = DI::cache()->get($cachekey);
1039                         if (!is_null($data)) {
1040                                 return $data;
1041                         }
1042                 }
1043
1044                 $data = self::createActivityFromItem($item_id);
1045
1046                 DI::cache()->set($cachekey, $data, Duration::QUARTER_HOUR);
1047                 return $data;
1048         }
1049
1050         /**
1051          * Creates an activity array for a given item id
1052          *
1053          * @param integer $item_id
1054          * @param boolean $object_mode Is the activity item is used inside another object?
1055          *
1056          * @return false|array
1057          * @throws \Exception
1058          */
1059         public static function createActivityFromItem(int $item_id, bool $object_mode = false)
1060         {
1061                 Logger::info('Fetching activity', ['item' => $item_id]);
1062                 $item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['id' => $item_id, 'parent-network' => Protocol::NATIVE_SUPPORT]);
1063                 if (!DBA::isResult($item)) {
1064                         return false;
1065                 }
1066
1067                 // In case of a forum post ensure to return the original post if author and forum are on the same machine
1068                 if (($item['gravity'] == GRAVITY_PARENT) && !empty($item['forum_mode'])) {
1069                         $author = Contact::getById($item['author-id'], ['nurl']);
1070                         if (!empty($author['nurl'])) {
1071                                 $self = Contact::selectFirst(['uid'], ['nurl' => $author['nurl'], 'self' => true]);
1072                                 if (!empty($self['uid'])) {
1073                                         $forum_item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['uri-id' => $item['uri-id'], 'uid' => $self['uid']]);
1074                                         if (DBA::isResult($forum_item)) {
1075                                                 $item = $forum_item;
1076                                         }
1077                                 }
1078                         }
1079                 }
1080
1081                 if (empty($item['uri-id'])) {
1082                         Logger::warning('Item without uri-id', ['item' => $item]);
1083                         return false;
1084                 }
1085
1086                 if (!$item['deleted']) {
1087                         $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
1088                         $conversation = DBA::selectFirst('conversation', ['source'], $condition);
1089                         if (!$item['origin'] && DBA::isResult($conversation)) {
1090                                 $data = json_decode($conversation['source'], true);
1091                                 if (!empty($data['type'])) {
1092                                         if (in_array($data['type'], ['Create', 'Update'])) {
1093                                                 if ($object_mode) {
1094                                                         unset($data['@context']);
1095                                                         unset($data['signature']);
1096                                                 }
1097                                                 Logger::info('Return stored conversation', ['item' => $item_id]);
1098                                                 return $data;
1099                                         } elseif (in_array('as:' . $data['type'], Receiver::CONTENT_TYPES)) {
1100                                                 if (!empty($data['@context'])) {
1101                                                         $context = $data['@context'];
1102                                                         unset($data['@context']);
1103                                                 }
1104                                                 unset($data['actor']);
1105                                                 $object = $data;
1106                                         }
1107                                 }
1108                         }
1109                 }
1110
1111                 $type = self::getTypeOfItem($item);
1112
1113                 if (!$object_mode) {
1114                         $data = ['@context' => $context ?? ActivityPub::CONTEXT];
1115
1116                         if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
1117                                 $type = 'Undo';
1118                         } elseif ($item['deleted']) {
1119                                 $type = 'Delete';
1120                         }
1121                 } else {
1122                         $data = [];
1123                 }
1124
1125                 if ($type == 'Delete') {
1126                         $data['id'] = Item::newURI($item['uid'], $item['guid']) . '/' . $type;;
1127                 } elseif (($item['gravity'] == GRAVITY_ACTIVITY) && ($type != 'Undo')) {
1128                         $data['id'] = $item['uri'];
1129                 } else {
1130                         $data['id'] = $item['uri'] . '/' . $type;
1131                 }
1132
1133                 $data['type'] = $type;
1134
1135                 if (($type != 'Announce') || ($item['gravity'] != GRAVITY_PARENT)) {
1136                         $data['actor'] = $item['author-link'];
1137                 } else {
1138                         $data['actor'] = $item['owner-link'];
1139                 }
1140
1141                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1142
1143                 $data['instrument'] = self::getService();
1144
1145                 $data = array_merge($data, self::createPermissionBlockForItem($item, false));
1146
1147                 if (in_array($data['type'], ['Create', 'Update', 'Delete'])) {
1148                         $data['object'] = $object ?? self::createNote($item);
1149                 } elseif ($data['type'] == 'Add') {
1150                         $data = self::createAddTag($item, $data);
1151                 } elseif ($data['type'] == 'Announce') {
1152                         if ($item['verb'] == ACTIVITY::ANNOUNCE) {
1153                                 $data['object'] = $item['thr-parent'];
1154                         } else {
1155                                 $data = self::createAnnounce($item, $data);
1156                         }
1157                 } elseif ($data['type'] == 'Follow') {
1158                         $data['object'] = $item['parent-uri'];
1159                 } elseif ($data['type'] == 'Undo') {
1160                         $data['object'] = self::createActivityFromItem($item_id, true);
1161                 } else {
1162                         $data['diaspora:guid'] = $item['guid'];
1163                         if (!empty($item['signed_text'])) {
1164                                 $data['diaspora:like'] = $item['signed_text'];
1165                         }
1166                         $data['object'] = $item['thr-parent'];
1167                 }
1168
1169                 if (!empty($item['contact-uid'])) {
1170                         $uid = $item['contact-uid'];
1171                 } else {
1172                         $uid = $item['uid'];
1173                 }
1174
1175                 $owner = User::getOwnerDataById($uid);
1176
1177                 Logger::info('Fetched activity', ['item' => $item_id, 'uid' => $uid]);
1178
1179                 // We don't sign if we aren't the actor. This is important for relaying content especially for forums
1180                 if (!$object_mode && !empty($owner) && ($data['actor'] == $owner['url'])) {
1181                         return LDSignature::sign($data, $owner);
1182                 } else {
1183                         return $data;
1184                 }
1185
1186                 /// @todo Create "conversation" entry
1187         }
1188
1189         /**
1190          * Creates a location entry for a given item array
1191          *
1192          * @param array $item
1193          *
1194          * @return array with location array
1195          */
1196         private static function createLocation($item)
1197         {
1198                 $location = ['type' => 'Place'];
1199
1200                 if (!empty($item['location'])) {
1201                         $location['name'] = $item['location'];
1202                 }
1203
1204                 $coord = [];
1205
1206                 if (empty($item['coord'])) {
1207                         $coord = Map::getCoordinates($item['location']);
1208                 } else {
1209                         $coords = explode(' ', $item['coord']);
1210                         if (count($coords) == 2) {
1211                                 $coord = ['lat' => $coords[0], 'lon' => $coords[1]];
1212                         }
1213                 }
1214
1215                 if (!empty($coord['lat']) && !empty($coord['lon'])) {
1216                         $location['latitude'] = $coord['lat'];
1217                         $location['longitude'] = $coord['lon'];
1218                 }
1219
1220                 return $location;
1221         }
1222
1223         /**
1224          * Returns a tag array for a given item array
1225          *
1226          * @param array $item
1227          *
1228          * @return array of tags
1229          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1230          */
1231         private static function createTagList($item)
1232         {
1233                 $tags = [];
1234
1235                 $terms = Tag::getByURIId($item['uri-id'], [Tag::HASHTAG, Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1236                 foreach ($terms as $term) {
1237                         if ($term['type'] == Tag::HASHTAG) {
1238                                 $url = DI::baseUrl() . '/search?tag=' . urlencode($term['name']);
1239                                 $tags[] = ['type' => 'Hashtag', 'href' => $url, 'name' => '#' . $term['name']];
1240                         } else {
1241                                 $contact = Contact::getByURL($term['url'], false, ['addr']);
1242                                 if (empty($contact)) {
1243                                         continue;
1244                                 }
1245                                 if (!empty($contact['addr'])) {
1246                                         $mention = '@' . $contact['addr'];
1247                                 } else {
1248                                         $mention = '@' . $term['url'];
1249                                 }
1250
1251                                 $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
1252                         }
1253                 }
1254
1255                 $announce = self::getAnnounceArray($item);
1256                 // Mention the original author upon commented reshares
1257                 if (!empty($announce['comment'])) {
1258                         $tags[] = ['type' => 'Mention', 'href' => $announce['actor']['url'], 'name' => '@' . $announce['actor']['addr']];
1259                 }
1260
1261                 return $tags;
1262         }
1263
1264         /**
1265          * Adds attachment data to the JSON document
1266          *
1267          * @param array  $item Data of the item that is to be posted
1268          * @param string $type Object type
1269          *
1270          * @return array with attachment data
1271          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1272          */
1273         private static function createAttachmentList($item, $type)
1274         {
1275                 $attachments = [];
1276
1277                 $uriids = [$item['uri-id']];
1278                 $shared = BBCode::fetchShareAttributes($item['body']);
1279                 if (!empty($shared['guid'])) {
1280                         $shared_item = Post::selectFirst(['uri-id'], ['guid' => $shared['guid']]);
1281                         if (!empty($shared_item['uri-id'])) {
1282                                 $uriids[] = $shared_item['uri-id'];
1283                         }
1284                 }
1285
1286                 $urls = [];
1287                 foreach ($uriids as $uriid) {
1288                         foreach (Post\Media::getByURIId($uriid, [Post\Media::DOCUMENT, Post\Media::TORRENT]) as $attachment) {
1289                                 if (in_array($attachment['url'], $urls)) {
1290                                         continue;
1291                                 }
1292                                 $urls[] = $attachment['url'];
1293
1294                                 $attach = ['type' => 'Document',
1295                                         'mediaType' => $attachment['mimetype'],
1296                                         'url' => $attachment['url'],
1297                                         'name' => $attachment['description']];
1298
1299                                 if (!empty($attachment['height'])) {
1300                                         $attach['height'] = $attachment['height'];
1301                                 }
1302
1303                                 if (!empty($attachment['width'])) {
1304                                         $attach['width'] = $attachment['width'];
1305                                 }
1306
1307                                 if (!empty($attachment['preview'])) {
1308                                         $attach['image'] = $attachment['preview'];
1309                                 }
1310
1311                                 $attachments[] = $attach;
1312                         }
1313                 }
1314
1315                 if ($type != 'Note') {
1316                         return $attachments;
1317                 }
1318
1319                 foreach ($uriids as $uriid) {
1320                         foreach (Post\Media::getByURIId($uriid, [Post\Media::AUDIO, Post\Media::IMAGE, Post\Media::VIDEO]) as $attachment) {
1321                                 if (in_array($attachment['url'], $urls)) {
1322                                         continue;
1323                                 }
1324                                 $urls[] = $attachment['url'];
1325
1326                                 $attach = ['type' => 'Document',
1327                                         'mediaType' => $attachment['mimetype'],
1328                                         'url' => $attachment['url'],
1329                                         'name' => $attachment['description']];
1330
1331                                 if (!empty($attachment['height'])) {
1332                                         $attach['height'] = $attachment['height'];
1333                                 }
1334
1335                                 if (!empty($attachment['width'])) {
1336                                         $attach['width'] = $attachment['width'];
1337                                 }
1338
1339                                 if (!empty($attachment['preview'])) {
1340                                         $attach['image'] = $attachment['preview'];
1341                                 }
1342
1343                                 $attachments[] = $attach;
1344                         }
1345                         // Currently deactivated, since it creates side effects on Mastodon and Pleroma.
1346                         // It will be activated, once this cleared.
1347                         /*
1348                         foreach (Post\Media::getByURIId($uriid, [Post\Media::HTML]) as $attachment) {
1349                                 if (in_array($attachment['url'], $urls)) {
1350                                         continue;
1351                                 }
1352                                 $urls[] = $attachment['url'];
1353
1354                                 $attachments[] = ['type' => 'Page',
1355                                         'mediaType' => $attachment['mimetype'],
1356                                         'url' => $attachment['url'],
1357                                         'name' => $attachment['description']];
1358                         }*/
1359                 }
1360
1361                 return $attachments;
1362         }
1363
1364         /**
1365          * Callback function to replace a Friendica style mention in a mention for a summary
1366          *
1367          * @param array $match Matching values for the callback
1368          * @return string Replaced mention
1369          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1370          */
1371         private static function mentionAddrCallback($match)
1372         {
1373                 if (empty($match[1])) {
1374                         return '';
1375                 }
1376
1377                 $data = Contact::getByURL($match[1], false, ['addr']);
1378                 if (empty($data['addr'])) {
1379                         return $match[0];
1380                 }
1381
1382                 return '@' . $data['addr'];
1383         }
1384
1385         /**
1386          * Remove image elements since they are added as attachment
1387          *
1388          * @param string $body
1389          *
1390          * @return string with removed images
1391          */
1392         private static function removePictures($body)
1393         {
1394                 // Simplify image codes
1395                 $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $body);
1396                 $body = preg_replace("/\[img\=(.*?)\](.*?)\[\/img\]/ism", '[img]$1[/img]', $body);
1397
1398                 // Now remove local links
1399                 $body = preg_replace_callback(
1400                         '/\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]/Usi',
1401                         function ($match) {
1402                                 // We remove the link when it is a link to a local photo page
1403                                 if (Photo::isLocalPage($match[1])) {
1404                                         return '';
1405                                 }
1406                                 // otherwise we just return the link
1407                                 return '[url]' . $match[1] . '[/url]';
1408                         },
1409                         $body
1410                 );
1411
1412                 // Remove all pictures
1413                 $body = preg_replace("/\[img\]([^\[\]]*)\[\/img\]/Usi", '', $body);
1414
1415                 return $body;
1416         }
1417
1418         /**
1419          * Fetches the "context" value for a givem item array from the "conversation" table
1420          *
1421          * @param array $item
1422          *
1423          * @return string with context url
1424          * @throws \Exception
1425          */
1426         private static function fetchContextURLForItem($item)
1427         {
1428                 $conversation = DBA::selectFirst('conversation', ['conversation-href', 'conversation-uri'], ['item-uri' => $item['parent-uri']]);
1429                 if (DBA::isResult($conversation) && !empty($conversation['conversation-href'])) {
1430                         $context_uri = $conversation['conversation-href'];
1431                 } elseif (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
1432                         $context_uri = $conversation['conversation-uri'];
1433                 } else {
1434                         $context_uri = $item['parent-uri'] . '#context';
1435                 }
1436                 return $context_uri;
1437         }
1438
1439         /**
1440          * Returns if the post contains sensitive content ("nsfw")
1441          *
1442          * @param integer $uri_id
1443          *
1444          * @return boolean
1445          * @throws \Exception
1446          */
1447         private static function isSensitive($uri_id)
1448         {
1449                 return DBA::exists('tag-view', ['uri-id' => $uri_id, 'name' => 'nsfw']);
1450         }
1451
1452         /**
1453          * Creates event data
1454          *
1455          * @param array $item
1456          *
1457          * @return array with the event data
1458          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1459          */
1460         private static function createEvent($item)
1461         {
1462                 $event = [];
1463                 $event['name'] = $item['event-summary'];
1464                 $event['content'] = BBCode::convertForUriId($item['uri-id'], $item['event-desc'], BBCode::ACTIVITYPUB);
1465                 $event['startTime'] = DateTimeFormat::utc($item['event-start'] . '+00:00', DateTimeFormat::ATOM);
1466
1467                 if (!$item['event-nofinish']) {
1468                         $event['endTime'] = DateTimeFormat::utc($item['event-finish'] . '+00:00', DateTimeFormat::ATOM);
1469                 }
1470
1471                 if (!empty($item['event-location'])) {
1472                         $item['location'] = $item['event-location'];
1473                         $event['location'] = self::createLocation($item);
1474                 }
1475
1476                 $event['dfrn:adjust'] = (bool)$item['event-adjust'];
1477
1478                 return $event;
1479         }
1480
1481         /**
1482          * Creates a note/article object array
1483          *
1484          * @param array $item
1485          *
1486          * @return array with the object data
1487          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1488          * @throws \ImagickException
1489          */
1490         public static function createNote($item)
1491         {
1492                 if (empty($item)) {
1493                         return [];
1494                 }
1495
1496                 if ($item['event-type'] == 'event') {
1497                         $type = 'Event';
1498                 } elseif (!empty($item['title'])) {
1499                         $type = 'Article';
1500                 } else {
1501                         $type = 'Note';
1502                 }
1503
1504                 if ($item['deleted']) {
1505                         $type = 'Tombstone';
1506                 }
1507
1508                 $data = [];
1509                 $data['id'] = $item['uri'];
1510                 $data['type'] = $type;
1511
1512                 if ($item['deleted']) {
1513                         return $data;
1514                 }
1515
1516                 $data['summary'] = BBCode::toPlaintext(BBCode::getAbstract($item['body'], Protocol::ACTIVITYPUB));
1517
1518                 if ($item['uri'] != $item['thr-parent']) {
1519                         $data['inReplyTo'] = $item['thr-parent'];
1520                 } else {
1521                         $data['inReplyTo'] = null;
1522                 }
1523
1524                 $data['diaspora:guid'] = $item['guid'];
1525                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1526
1527                 if ($item['created'] != $item['edited']) {
1528                         $data['updated'] = DateTimeFormat::utc($item['edited'] . '+00:00', DateTimeFormat::ATOM);
1529                 }
1530
1531                 $data['url'] = $item['plink'];
1532                 $data['attributedTo'] = $item['author-link'];
1533                 $data['sensitive'] = self::isSensitive($item['uri-id']);
1534                 $data['context'] = self::fetchContextURLForItem($item);
1535
1536                 if (!empty($item['title'])) {
1537                         $data['name'] = BBCode::toPlaintext($item['title'], false);
1538                 }
1539
1540                 $permission_block = self::createPermissionBlockForItem($item, false);
1541
1542                 $body = $item['body'];
1543
1544                 if ($type == 'Note') {
1545                         $body = $item['raw-body'] ?? self::removePictures($body);
1546                 }
1547
1548                 /**
1549                  * @todo Improve the automated summary
1550                  * This part is currently deactivated. The automated summary seems to be more
1551                  * confusing than helping. But possibly we will find a better way.
1552                  * So the code is left here for now as a reminder
1553                  *
1554                  * } elseif (($type == 'Article') && empty($data['summary'])) {
1555                  *              $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1556                  *              $summary = preg_replace_callback($regexp, ['self', 'mentionAddrCallback'], $body);
1557                  *              $data['summary'] = BBCode::toPlaintext(Plaintext::shorten(self::removePictures($summary), 1000));
1558                  * }
1559                  */
1560
1561                 if (empty($item['uid']) || !Feature::isEnabled($item['uid'], 'explicit_mentions')) {
1562                         $body = self::prependMentions($body, $item['uri-id'], $item['author-link']);
1563                 }
1564
1565                 if ($type == 'Event') {
1566                         $data = array_merge($data, self::createEvent($item));
1567                 } else {
1568                         $body = BBCode::setMentionsToNicknames($body);
1569
1570                         $data['content'] = BBCode::convertForUriId($item['uri-id'], $body, BBCode::ACTIVITYPUB);
1571                 }
1572
1573                 // The regular "content" field does contain a minimized HTML. This is done since systems like
1574                 // Mastodon has got problems with - for example - embedded pictures.
1575                 // The contentMap does contain the unmodified HTML.
1576                 $language = self::getLanguage($item);
1577                 if (!empty($language)) {
1578                         $richbody = BBCode::setMentionsToNicknames($item['body'] ?? '');
1579                         $richbody = BBCode::removeAttachment($richbody);
1580
1581                         $data['contentMap'][$language] = BBCode::convertForUriId($item['uri-id'], $richbody, BBCode::EXTERNAL);
1582                 }
1583
1584                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
1585
1586                 if (!empty($item['signed_text']) && ($item['uri'] != $item['thr-parent'])) {
1587                         $data['diaspora:comment'] = $item['signed_text'];
1588                 }
1589
1590                 $data['attachment'] = self::createAttachmentList($item, $type);
1591                 $data['tag'] = self::createTagList($item);
1592
1593                 if (empty($data['location']) && (!empty($item['coord']) || !empty($item['location']))) {
1594                         $data['location'] = self::createLocation($item);
1595                 }
1596
1597                 if (!empty($item['app'])) {
1598                         $data['generator'] = ['type' => 'Application', 'name' => $item['app']];
1599                 }
1600
1601                 $data = array_merge($data, $permission_block);
1602
1603                 return $data;
1604         }
1605
1606         /**
1607          * Fetches the language from the post, the user or the system.
1608          *
1609          * @param array $item
1610          *
1611          * @return string language string
1612          */
1613         private static function getLanguage(array $item)
1614         {
1615                 // Try to fetch the language from the post itself
1616                 if (!empty($item['language'])) {
1617                         $languages = array_keys(json_decode($item['language'], true));
1618                         if (!empty($languages[0])) {
1619                                 return $languages[0];
1620                         }
1621                 }
1622
1623                 // Otherwise use the user's language
1624                 if (!empty($item['uid'])) {
1625                         $user = DBA::selectFirst('user', ['language'], ['uid' => $item['uid']]);
1626                         if (!empty($user['language'])) {
1627                                 return $user['language'];
1628                         }
1629                 }
1630
1631                 // And finally just use the system language
1632                 return DI::config()->get('system', 'language');
1633         }
1634
1635         /**
1636          * Creates an an "add tag" entry
1637          *
1638          * @param array $item
1639          * @param array $data activity data
1640          *
1641          * @return array with activity data for adding tags
1642          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1643          * @throws \ImagickException
1644          */
1645         private static function createAddTag($item, $data)
1646         {
1647                 $object = XML::parseString($item['object']);
1648                 $target = XML::parseString($item["target"]);
1649
1650                 $data['diaspora:guid'] = $item['guid'];
1651                 $data['actor'] = $item['author-link'];
1652                 $data['target'] = (string)$target->id;
1653                 $data['summary'] = BBCode::toPlaintext($item['body']);
1654                 $data['object'] = ['id' => (string)$object->id, 'type' => 'tag', 'name' => (string)$object->title, 'content' => (string)$object->content];
1655
1656                 return $data;
1657         }
1658
1659         /**
1660          * Creates an announce object entry
1661          *
1662          * @param array $item
1663          * @param array $data activity data
1664          *
1665          * @return array with activity data
1666          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1667          * @throws \ImagickException
1668          */
1669         private static function createAnnounce($item, $data)
1670         {
1671                 $orig_body = $item['body'];
1672                 $announce = self::getAnnounceArray($item);
1673                 if (empty($announce)) {
1674                         $data['type'] = 'Create';
1675                         $data['object'] = self::createNote($item);
1676                         return $data;
1677                 }
1678
1679                 if (empty($announce['comment'])) {
1680                         // Pure announce, without a quote
1681                         $data['type'] = 'Announce';
1682                         $data['object'] = $announce['object']['uri'];
1683                         return $data;
1684                 }
1685
1686                 // Quote
1687                 $data['type'] = 'Create';
1688                 $item['body'] = $announce['comment'] . "\n" . $announce['object']['plink'];
1689                 $data['object'] = self::createNote($item);
1690
1691                 /// @todo Finally descide how to implement this in AP. This is a possible way:
1692                 $data['object']['attachment'][] = self::createNote($announce['object']);
1693
1694                 $data['object']['source']['content'] = $orig_body;
1695                 return $data;
1696         }
1697
1698         /**
1699          * Return announce related data if the item is an annunce
1700          *
1701          * @param array $item
1702          *
1703          * @return array
1704          */
1705         public static function getAnnounceArray($item)
1706         {
1707                 $reshared = Item::getShareArray($item);
1708                 if (empty($reshared['guid'])) {
1709                         return [];
1710                 }
1711
1712                 $reshared_item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['guid' => $reshared['guid']]);
1713                 if (!DBA::isResult($reshared_item)) {
1714                         return [];
1715                 }
1716
1717                 if (!in_array($reshared_item['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN])) {
1718                         return [];
1719                 }
1720
1721                 $profile = APContact::getByURL($reshared_item['author-link'], false);
1722                 if (empty($profile)) {
1723                         return [];
1724                 }
1725
1726                 return ['object' => $reshared_item, 'actor' => $profile, 'comment' => $reshared['comment']];
1727         }
1728
1729         /**
1730          * Checks if the provided item array is an announce
1731          *
1732          * @param array $item
1733          *
1734          * @return boolean
1735          */
1736         public static function isAnnounce($item)
1737         {
1738                 if (!empty($item['verb']) && ($item['verb'] == Activity::ANNOUNCE)) {
1739                         return true;
1740                 }
1741
1742                 $announce = self::getAnnounceArray($item);
1743                 if (empty($announce)) {
1744                         return false;
1745                 }
1746
1747                 return empty($announce['comment']);
1748         }
1749
1750         /**
1751          * Creates an activity id for a given contact id
1752          *
1753          * @param integer $cid Contact ID of target
1754          *
1755          * @return bool|string activity id
1756          */
1757         public static function activityIDFromContact($cid)
1758         {
1759                 $contact = DBA::selectFirst('contact', ['uid', 'id', 'created'], ['id' => $cid]);
1760                 if (!DBA::isResult($contact)) {
1761                         return false;
1762                 }
1763
1764                 $hash = hash('ripemd128', $contact['uid'].'-'.$contact['id'].'-'.$contact['created']);
1765                 $uuid = substr($hash, 0, 8). '-' . substr($hash, 8, 4) . '-' . substr($hash, 12, 4) . '-' . substr($hash, 16, 4) . '-' . substr($hash, 20, 12);
1766                 return DI::baseUrl() . '/activity/' . $uuid;
1767         }
1768
1769         /**
1770          * Transmits a contact suggestion to a given inbox
1771          *
1772          * @param integer $uid           User ID
1773          * @param string  $inbox         Target inbox
1774          * @param integer $suggestion_id Suggestion ID
1775          *
1776          * @return boolean was the transmission successful?
1777          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1778          */
1779         public static function sendContactSuggestion($uid, $inbox, $suggestion_id)
1780         {
1781                 $owner = User::getOwnerDataById($uid);
1782
1783                 $suggestion = DI::fsuggest()->getById($suggestion_id);
1784
1785                 $data = ['@context' => ActivityPub::CONTEXT,
1786                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1787                         'type' => 'Announce',
1788                         'actor' => $owner['url'],
1789                         'object' => $suggestion->url,
1790                         'content' => $suggestion->note,
1791                         'instrument' => self::getService(),
1792                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1793                         'cc' => []];
1794
1795                 $signed = LDSignature::sign($data, $owner);
1796
1797                 Logger::log('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1798                 return HTTPSignature::transmit($signed, $inbox, $uid);
1799         }
1800
1801         /**
1802          * Transmits a profile relocation to a given inbox
1803          *
1804          * @param integer $uid   User ID
1805          * @param string  $inbox Target inbox
1806          *
1807          * @return boolean was the transmission successful?
1808          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1809          */
1810         public static function sendProfileRelocation($uid, $inbox)
1811         {
1812                 $owner = User::getOwnerDataById($uid);
1813
1814                 $data = ['@context' => ActivityPub::CONTEXT,
1815                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1816                         'type' => 'dfrn:relocate',
1817                         'actor' => $owner['url'],
1818                         'object' => $owner['url'],
1819                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1820                         'instrument' => self::getService(),
1821                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1822                         'cc' => []];
1823
1824                 $signed = LDSignature::sign($data, $owner);
1825
1826                 Logger::log('Deliver profile relocation for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1827                 return HTTPSignature::transmit($signed, $inbox, $uid);
1828         }
1829
1830         /**
1831          * Transmits a profile deletion to a given inbox
1832          *
1833          * @param integer $uid   User ID
1834          * @param string  $inbox Target inbox
1835          *
1836          * @return boolean was the transmission successful?
1837          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1838          */
1839         public static function sendProfileDeletion($uid, $inbox)
1840         {
1841                 $owner = User::getOwnerDataById($uid);
1842
1843                 if (empty($owner)) {
1844                         Logger::error('No owner data found, the deletion message cannot be processed.', ['user' => $uid]);
1845                         return false;
1846                 }
1847
1848                 if (empty($owner['uprvkey'])) {
1849                         Logger::error('No private key for owner found, the deletion message cannot be processed.', ['user' => $uid]);
1850                         return false;
1851                 }
1852
1853                 $data = ['@context' => ActivityPub::CONTEXT,
1854                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1855                         'type' => 'Delete',
1856                         'actor' => $owner['url'],
1857                         'object' => $owner['url'],
1858                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1859                         'instrument' => self::getService(),
1860                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1861                         'cc' => []];
1862
1863                 $signed = LDSignature::sign($data, $owner);
1864
1865                 Logger::log('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1866                 return HTTPSignature::transmit($signed, $inbox, $uid);
1867         }
1868
1869         /**
1870          * Transmits a profile change to a given inbox
1871          *
1872          * @param integer $uid   User ID
1873          * @param string  $inbox Target inbox
1874          *
1875          * @return boolean was the transmission successful?
1876          * @throws HTTPException\InternalServerErrorException
1877          * @throws HTTPException\NotFoundException
1878          * @throws \ImagickException
1879          */
1880         public static function sendProfileUpdate(int $uid, string $inbox): bool
1881         {
1882                 $owner = User::getOwnerDataById($uid);
1883                 $profile = APContact::getByURL($owner['url']);
1884
1885                 $data = ['@context' => ActivityPub::CONTEXT,
1886                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1887                         'type' => 'Update',
1888                         'actor' => $owner['url'],
1889                         'object' => self::getProfile($uid),
1890                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1891                         'instrument' => self::getService(),
1892                         'to' => [$profile['followers']],
1893                         'cc' => []];
1894
1895                 $signed = LDSignature::sign($data, $owner);
1896
1897                 Logger::log('Deliver profile update for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1898                 return HTTPSignature::transmit($signed, $inbox, $uid);
1899         }
1900
1901         /**
1902          * Transmits a given activity to a target
1903          *
1904          * @param string  $activity Type name
1905          * @param string  $target   Target profile
1906          * @param integer $uid      User ID
1907          * @return bool
1908          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1909          * @throws \ImagickException
1910          * @throws \Exception
1911          */
1912         public static function sendActivity($activity, $target, $uid, $id = '')
1913         {
1914                 $profile = APContact::getByURL($target);
1915                 if (empty($profile['inbox'])) {
1916                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1917                         return;
1918                 }
1919
1920                 $owner = User::getOwnerDataById($uid);
1921
1922                 if (empty($id)) {
1923                         $id = DI::baseUrl() . '/activity/' . System::createGUID();
1924                 }
1925
1926                 $data = ['@context' => ActivityPub::CONTEXT,
1927                         'id' => $id,
1928                         'type' => $activity,
1929                         'actor' => $owner['url'],
1930                         'object' => $profile['url'],
1931                         'instrument' => self::getService(),
1932                         'to' => [$profile['url']]];
1933
1934                 Logger::log('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid, Logger::DEBUG);
1935
1936                 $signed = LDSignature::sign($data, $owner);
1937                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1938         }
1939
1940         /**
1941          * Transmits a "follow object" activity to a target
1942          * This is a preparation for sending automated "follow" requests when receiving "Announce" messages
1943          *
1944          * @param string  $object Object URL
1945          * @param string  $target Target profile
1946          * @param integer $uid    User ID
1947          * @return bool
1948          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1949          * @throws \ImagickException
1950          * @throws \Exception
1951          */
1952         public static function sendFollowObject($object, $target, $uid = 0)
1953         {
1954                 $profile = APContact::getByURL($target);
1955                 if (empty($profile['inbox'])) {
1956                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1957                         return;
1958                 }
1959
1960                 if (empty($uid)) {
1961                         // Fetch the list of administrators
1962                         $admin_mail = explode(',', str_replace(' ', '', DI::config()->get('config', 'admin_email')));
1963
1964                         // We need to use some user as a sender. It doesn't care who it will send. We will use an administrator account.
1965                         $condition = ['verified' => true, 'blocked' => false, 'account_removed' => false, 'account_expired' => false, 'email' => $admin_mail];
1966                         $first_user = DBA::selectFirst('user', ['uid'], $condition);
1967                         $uid = $first_user['uid'];
1968                 }
1969
1970                 $condition = ['verb' => Activity::FOLLOW, 'uid' => 0, 'parent-uri' => $object,
1971                         'author-id' => Contact::getPublicIdByUserId($uid)];
1972                 if (Post::exists($condition)) {
1973                         Logger::log('Follow for ' . $object . ' for user ' . $uid . ' does already exist.', Logger::DEBUG);
1974                         return false;
1975                 }
1976
1977                 $owner = User::getOwnerDataById($uid);
1978
1979                 $data = ['@context' => ActivityPub::CONTEXT,
1980                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1981                         'type' => 'Follow',
1982                         'actor' => $owner['url'],
1983                         'object' => $object,
1984                         'instrument' => self::getService(),
1985                         'to' => [$profile['url']]];
1986
1987                 Logger::log('Sending follow ' . $object . ' to ' . $target . ' for user ' . $uid, Logger::DEBUG);
1988
1989                 $signed = LDSignature::sign($data, $owner);
1990                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1991         }
1992
1993         /**
1994          * Transmit a message that the contact request had been accepted
1995          *
1996          * @param string  $target Target profile
1997          * @param         $id
1998          * @param integer $uid    User ID
1999          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2000          * @throws \ImagickException
2001          */
2002         public static function sendContactAccept($target, $id, $uid)
2003         {
2004                 $profile = APContact::getByURL($target);
2005                 if (empty($profile['inbox'])) {
2006                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2007                         return;
2008                 }
2009
2010                 $owner = User::getOwnerDataById($uid);
2011                 $data = ['@context' => ActivityPub::CONTEXT,
2012                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2013                         'type' => 'Accept',
2014                         'actor' => $owner['url'],
2015                         'object' => [
2016                                 'id' => (string)$id,
2017                                 'type' => 'Follow',
2018                                 'actor' => $profile['url'],
2019                                 'object' => $owner['url']
2020                         ],
2021                         'instrument' => self::getService(),
2022                         'to' => [$profile['url']]];
2023
2024                 Logger::debug('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2025
2026                 $signed = LDSignature::sign($data, $owner);
2027                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2028         }
2029
2030         /**
2031          * Reject a contact request or terminates the contact relation
2032          *
2033          * @param string  $target Target profile
2034          * @param         $id
2035          * @param integer $uid    User ID
2036          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2037          * @throws \ImagickException
2038          */
2039         public static function sendContactReject($target, $id, $uid)
2040         {
2041                 $profile = APContact::getByURL($target);
2042                 if (empty($profile['inbox'])) {
2043                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2044                         return;
2045                 }
2046
2047                 $owner = User::getOwnerDataById($uid);
2048                 $data = ['@context' => ActivityPub::CONTEXT,
2049                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2050                         'type' => 'Reject',
2051                         'actor' => $owner['url'],
2052                         'object' => [
2053                                 'id' => (string)$id,
2054                                 'type' => 'Follow',
2055                                 'actor' => $profile['url'],
2056                                 'object' => $owner['url']
2057                         ],
2058                         'instrument' => self::getService(),
2059                         'to' => [$profile['url']]];
2060
2061                 Logger::debug('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2062
2063                 $signed = LDSignature::sign($data, $owner);
2064                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2065         }
2066
2067         /**
2068          * Transmits a message that we don't want to follow this contact anymore
2069          *
2070          * @param string  $target Target profile
2071          * @param integer $uid    User ID
2072          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2073          * @throws \ImagickException
2074          * @throws \Exception
2075          * @return bool success
2076          */
2077         public static function sendContactUndo($target, $cid, $uid)
2078         {
2079                 $profile = APContact::getByURL($target);
2080                 if (empty($profile['inbox'])) {
2081                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2082                         return false;
2083                 }
2084
2085                 $object_id = self::activityIDFromContact($cid);
2086                 if (empty($object_id)) {
2087                         return false;
2088                 }
2089
2090                 $id = DI::baseUrl() . '/activity/' . System::createGUID();
2091
2092                 $owner = User::getOwnerDataById($uid);
2093                 $data = ['@context' => ActivityPub::CONTEXT,
2094                         'id' => $id,
2095                         'type' => 'Undo',
2096                         'actor' => $owner['url'],
2097                         'object' => ['id' => $object_id, 'type' => 'Follow',
2098                                 'actor' => $owner['url'],
2099                                 'object' => $profile['url']],
2100                         'instrument' => self::getService(),
2101                         'to' => [$profile['url']]];
2102
2103                 Logger::log('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id, Logger::DEBUG);
2104
2105                 $signed = LDSignature::sign($data, $owner);
2106                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2107         }
2108
2109         private static function prependMentions($body, int $uriid, string $authorLink)
2110         {
2111                 $mentions = [];
2112
2113                 foreach (Tag::getByURIId($uriid, [Tag::IMPLICIT_MENTION]) as $tag) {
2114                         $profile = Contact::getByURL($tag['url'], false, ['addr', 'contact-type', 'nick']);
2115                         if (!empty($profile['addr'])
2116                                 && $profile['contact-type'] != Contact::TYPE_COMMUNITY
2117                                 && !strstr($body, $profile['addr'])
2118                                 && !strstr($body, $tag['url'])
2119                                 && $tag['url'] !== $authorLink
2120                         ) {
2121                                 $mentions[] = '@[url=' . $tag['url'] . ']' . $profile['nick'] . '[/url]';
2122                         }
2123                 }
2124
2125                 $mentions[] = $body;
2126
2127                 return implode(' ', $mentions);
2128         }
2129 }