src/Protocol/ActivityPub/Transmitter.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol\ActivityPub;
  23
  24 use Friendica\Content\Feature;
  25 use Friendica\Content\Text\BBCode;
  26 use Friendica\Content\Text\Plaintext;
  27 use Friendica\Core\Cache\Duration;
  28 use Friendica\Core\Logger;
  29 use Friendica\Core\Protocol;
  30 use Friendica\Core\System;
  31 use Friendica\Database\DBA;
  32 use Friendica\DI;
  33 use Friendica\Model\APContact;
  34 use Friendica\Model\Contact;
  35 use Friendica\Model\Conversation;
  36 use Friendica\Model\Item;
  37 use Friendica\Model\ItemURI;
  38 use Friendica\Model\Profile;
  39 use Friendica\Model\Photo;
  40 use Friendica\Model\Tag;
  41 use Friendica\Model\User;
  42 use Friendica\Protocol\Activity;
  43 use Friendica\Protocol\ActivityPub;
  44 use Friendica\Util\DateTimeFormat;
  45 use Friendica\Util\HTTPSignature;
  46 use Friendica\Util\Images;
  47 use Friendica\Util\JsonLD;
  48 use Friendica\Util\LDSignature;
  49 use Friendica\Util\Map;
  50 use Friendica\Util\Network;
  51 use Friendica\Util\XML;
  52
  53 require_once 'include/api.php';
  54 require_once 'mod/share.php';
  55
  56 /**
  57  * ActivityPub Transmitter Protocol class
  58  *
  59  * To-Do:
  60  * @todo Undo Announce
  61  */
  62 class Transmitter
  63 {
  64         /**
  65          * Add relay servers to the list of inboxes
  66          *
  67          * @param array $inboxes
  68          * @return array inboxes with added relay servers
  69          */
  70         public static function addRelayServerInboxes(array $inboxes = [])
  71         {
  72                 $contacts = DBA::select('apcontact', ['inbox'],
  73                         ["`type` = ? AND `url` IN (SELECT `url` FROM `contact` WHERE `uid` = ? AND `rel` IN (?, ?))",
  74                                 'Application', 0, Contact::FOLLOWER, Contact::FRIEND]);
  75                 while ($contact = DBA::fetch($contacts)) {
  76                         $inboxes[] = $contact['inbox'];
  77                 }
  78                 DBA::close($contacts);
  79
  80                 return $inboxes;
  81         }
  82
  83         /**
  84          * Subscribe to a relay
  85          *
  86          * @param string $url Subscribe actor url
  87          * @return bool success
  88          */
  89         public static function sendRelayFollow(string $url)
  90         {
  91                 $contact = Contact::getByURL($url);
  92                 if (empty($contact)) {
  93                         return false;
  94                 }
  95
  96                 $activity_id = ActivityPub\Transmitter::activityIDFromContact($contact['id']);
  97                 $success = ActivityPub\Transmitter::sendActivity('Follow', $url, 0, $activity_id);
  98                 if ($success) {
  99                         $rel = $contact['rel'] == Contact::SHARING ? Contact::FRIEND : Contact::FOLLOWER;
 100                         DBA::update('contact', ['rel' => $rel], ['id' => $contact['id']]);
 101                 }
 102
 103                 return $success;
 104         }
 105
 106         /**
 107          * Unsubscribe from a relay
 108          *
 109          * @param string $url   Subscribe actor url
 110          * @param bool   $force Set the relay status as non follower even if unsubscribe hadn't worked
 111          * @return bool success
 112          */
 113         public static function sendRelayUndoFollow(string $url, bool $force = false)
 114         {
 115                 $contact = Contact::getByURL($url);
 116                 if (empty($contact)) {
 117                         return false;
 118                 }
 119
 120                 $success = self::sendContactUndo($url, $contact['id'], 0);
 121                 if ($success || $force) {
 122                         $rel = $contact['rel'] == Contact::FRIEND ? Contact::SHARING : Contact::NOTHING;
 123                         DBA::update('contact', ['rel' => $rel], ['id' => $contact['id']]);
 124                 }
 125
 126                 return $success;
 127         }
 128
 129         /**
 130          * Collects a list of contacts of the given owner
 131          *
 132          * @param array     $owner  Owner array
 133          * @param int|array $rel    The relevant value(s) contact.rel should match
 134          * @param string    $module The name of the relevant AP endpoint module (followers|following)
 135          * @param integer   $page   Page number
 136          *
 137          * @return array of owners
 138          * @throws \Exception
 139          */
 140         public static function getContacts($owner, $rel, $module, $page = null)
 141         {
 142                 $parameters = [
 143                         'rel' => $rel,
 144                         'uid' => $owner['uid'],
 145                         'self' => false,
 146                         'deleted' => false,
 147                         'hidden' => false,
 148                         'archive' => false,
 149                         'pending' => false
 150                 ];
 151                 $condition = DBA::buildCondition($parameters);
 152
 153                 $sql = "SELECT COUNT(*) as `count`
 154                         FROM `contact`
 155                         JOIN `apcontact` ON `apcontact`.`url` = `contact`.`url`
 156                         " . $condition;
 157
 158                 $contacts = DBA::fetchFirst($sql, ...$parameters);
 159
 160                 $modulePath = '/' . $module . '/';
 161
 162                 $data = ['@context' => ActivityPub::CONTEXT];
 163                 $data['id'] = DI::baseUrl() . $modulePath . $owner['nickname'];
 164                 $data['type'] = 'OrderedCollection';
 165                 $data['totalItems'] = $contacts['count'];
 166
 167                 // When we hide our friends we will only show the pure number but don't allow more.
 168                 $profile = Profile::getByUID($owner['uid']);
 169                 if (!empty($profile['hide-friends'])) {
 170                         return $data;
 171                 }
 172
 173                 if (empty($page)) {
 174                         $data['first'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=1';
 175                 } else {
 176                         $data['type'] = 'OrderedCollectionPage';
 177                         $list = [];
 178
 179                         $sql = "SELECT `contact`.`url`
 180                                 FROM `contact`
 181                                 JOIN `apcontact` ON `apcontact`.`url` = `contact`.`url`
 182                                 " . $condition . "
 183                                 LIMIT ?, ?";
 184
 185                         $parameters[] = ($page - 1) * 100;
 186                         $parameters[] = 100;
 187
 188                         $contacts = DBA::p($sql, ...$parameters);
 189                         while ($contact = DBA::fetch($contacts)) {
 190                                 $list[] = $contact['url'];
 191                         }
 192                         DBA::close($contacts);
 193
 194                         if (!empty($list)) {
 195                                 $data['next'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=' . ($page + 1);
 196                         }
 197
 198                         $data['partOf'] = DI::baseUrl() . $modulePath . $owner['nickname'];
 199
 200                         $data['orderedItems'] = $list;
 201                 }
 202
 203                 return $data;
 204         }
 205
 206         /**
 207          * Public posts for the given owner
 208          *
 209          * @param array   $owner     Owner array
 210          * @param integer $page      Page number
 211          * @param string  $requester URL of requesting account
 212          *
 213          * @return array of posts
 214          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 215          * @throws \ImagickException
 216          */
 217         public static function getOutbox($owner, $page = null, $requester = '')
 218         {
 219                 $public_contact = Contact::getIdForURL($owner['url']);
 220                 $condition = ['uid' => 0, 'contact-id' => $public_contact,
 221                         'private' => [Item::PUBLIC, Item::UNLISTED]];
 222
 223                 if (!empty($requester)) {
 224                         $requester_id = Contact::getIdForURL($requester, $owner['uid']);
 225                         if (!empty($requester_id)) {
 226                                 $permissionSets = DI::permissionSet()->selectByContactId($requester_id, $owner['uid']);
 227                                 if (!empty($permissionSets)) {
 228                                         $condition = ['uid' => $owner['uid'], 'origin' => true,
 229                                                 'psid' => array_merge($permissionSets->column('id'),
 230                                                         [DI::permissionSet()->getIdFromACL($owner['uid'], '', '', '', '')])];
 231                                 }
 232                         }
 233                 }
 234
 235                 $condition = array_merge($condition,
 236                         ['author-id' => $public_contact,
 237                         'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT],
 238                         'deleted' => false, 'visible' => true, 'moderated' => false]);
 239
 240                 $count = DBA::count('item', $condition);
 241
 242                 $data = ['@context' => ActivityPub::CONTEXT];
 243                 $data['id'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
 244                 $data['type'] = 'OrderedCollection';
 245                 $data['totalItems'] = $count;
 246
 247                 if (empty($page)) {
 248                         $data['first'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=1';
 249                 } else {
 250                         $data['type'] = 'OrderedCollectionPage';
 251                         $list = [];
 252
 253                         $condition['parent-network'] = Protocol::NATIVE_SUPPORT;
 254
 255                         $items = Item::select(['id'], $condition, ['limit' => [($page - 1) * 20, 20], 'order' => ['created' => true]]);
 256                         while ($item = Item::fetch($items)) {
 257                                 $activity = self::createActivityFromItem($item['id'], true);
 258                                 $activity['type'] = $activity['type'] == 'Update' ? 'Create' : $activity['type'];
 259
 260                                 // Only list "Create" activity objects here, no reshares
 261                                 if (!empty($activity['object']) && ($activity['type'] == 'Create')) {
 262                                         $list[] = $activity['object'];
 263                                 }
 264                         }
 265
 266                         if (!empty($list)) {
 267                                 $data['next'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=' . ($page + 1);
 268                         }
 269
 270                         $data['partOf'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
 271
 272                         $data['orderedItems'] = $list;
 273                 }
 274
 275                 return $data;
 276         }
 277
 278         /**
 279          * Return the service array containing information the used software and it's url
 280          *
 281          * @return array with service data
 282          */
 283         private static function getService()
 284         {
 285                 return ['type' => 'Service',
 286                         'name' =>  FRIENDICA_PLATFORM . " '" . FRIENDICA_CODENAME . "' " . FRIENDICA_VERSION . '-' . DB_UPDATE_VERSION,
 287                         'url' => DI::baseUrl()->get()];
 288         }
 289
 290         /**
 291          * Return the ActivityPub profile of the given user
 292          *
 293          * @param integer $uid User ID
 294          * @return array with profile data
 295          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 296          */
 297         public static function getProfile($uid)
 298         {
 299                 if ($uid != 0) {
 300                         $condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
 301                                 'account_removed' => false, 'verified' => true];
 302                         $fields = ['guid', 'nickname', 'pubkey', 'account-type', 'page-flags'];
 303                         $user = DBA::selectFirst('user', $fields, $condition);
 304                         if (!DBA::isResult($user)) {
 305                                 return [];
 306                         }
 307
 308                         $fields = ['locality', 'region', 'country-name'];
 309                         $profile = DBA::selectFirst('profile', $fields, ['uid' => $uid]);
 310                         if (!DBA::isResult($profile)) {
 311                                 return [];
 312                         }
 313
 314                         $fields = ['name', 'url', 'location', 'about', 'avatar', 'photo'];
 315                         $contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
 316                         if (!DBA::isResult($contact)) {
 317                                 return [];
 318                         }
 319                 } else {
 320                         $contact = User::getSystemAccount();
 321                         $user = ['guid' => '', 'nickname' => $contact['nick'], 'pubkey' => $contact['pubkey'],
 322                                 'account-type' => $contact['contact-type'], 'page-flags' => User::PAGE_FLAGS_NORMAL];
 323                         $profile = ['locality' => '', 'region' => '', 'country-name' => ''];
 324                 }
 325
 326                 $data = ['@context' => ActivityPub::CONTEXT];
 327                 $data['id'] = $contact['url'];
 328
 329                 if (!empty($user['guid'])) {
 330                         $data['diaspora:guid'] = $user['guid'];
 331                 }
 332
 333                 $data['type'] = ActivityPub::ACCOUNT_TYPES[$user['account-type']];
 334
 335                 if ($uid != 0) {
 336                         $data['following'] = DI::baseUrl() . '/following/' . $user['nickname'];
 337                         $data['followers'] = DI::baseUrl() . '/followers/' . $user['nickname'];
 338                         $data['inbox'] = DI::baseUrl() . '/inbox/' . $user['nickname'];
 339                         $data['outbox'] = DI::baseUrl() . '/outbox/' . $user['nickname'];
 340                 } else {
 341                         $data['inbox'] = DI::baseUrl() . '/friendica/inbox';
 342                 }
 343
 344                 $data['preferredUsername'] = $user['nickname'];
 345                 $data['name'] = $contact['name'];
 346
 347                 if (!empty($profile['country-name'] . $profile['region'] . $profile['locality'])) {
 348                         $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $profile['country-name'],
 349                                 'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
 350                 }
 351
 352                 if (!empty($contact['about'])) {
 353                         $data['summary'] = BBCode::convert($contact['about'], false);
 354                 }
 355
 356                 $data['url'] = $contact['url'];
 357                 $data['manuallyApprovesFollowers'] = in_array($user['page-flags'], [User::PAGE_FLAGS_NORMAL, User::PAGE_FLAGS_PRVGROUP]);
 358                 $data['publicKey'] = ['id' => $contact['url'] . '#main-key',
 359                         'owner' => $contact['url'],
 360                         'publicKeyPem' => $user['pubkey']];
 361                 $data['endpoints'] = ['sharedInbox' => DI::baseUrl() . '/inbox'];
 362                 $data['icon'] = ['type' => 'Image',
 363                         'url' => $contact['photo']];
 364
 365                 $data['generator'] = self::getService();
 366
 367                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
 368                 return $data;
 369         }
 370
 371         /**
 372          * @param string $username
 373          * @return array
 374          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 375          */
 376         public static function getDeletedUser($username)
 377         {
 378                 return [
 379                         '@context' => ActivityPub::CONTEXT,
 380                         'id' => DI::baseUrl() . '/profile/' . $username,
 381                         'type' => 'Tombstone',
 382                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 383                         'updated' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 384                         'deleted' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 385                 ];
 386         }
 387
 388         /**
 389          * Returns an array with permissions of a given item array
 390          *
 391          * @param array $item
 392          *
 393          * @return array with permissions
 394          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 395          * @throws \ImagickException
 396          */
 397         private static function fetchPermissionBlockFromConversation($item)
 398         {
 399                 if (empty($item['thr-parent'])) {
 400                         return [];
 401                 }
 402
 403                 $condition = ['item-uri' => $item['thr-parent'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
 404                 $conversation = DBA::selectFirst('conversation', ['source'], $condition);
 405                 if (!DBA::isResult($conversation)) {
 406                         return [];
 407                 }
 408
 409                 $activity = json_decode($conversation['source'], true);
 410
 411                 $actor = JsonLD::fetchElement($activity, 'actor', 'id');
 412                 $profile = APContact::getByURL($actor);
 413
 414                 $item_profile = APContact::getByURL($item['author-link']);
 415                 $exclude[] = $item['author-link'];
 416
 417                 if ($item['gravity'] == GRAVITY_PARENT) {
 418                         $exclude[] = $item['owner-link'];
 419                 }
 420
 421                 $permissions['to'][] = $actor;
 422
 423                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 424                         if (empty($activity[$element])) {
 425                                 continue;
 426                         }
 427                         if (is_string($activity[$element])) {
 428                                 $activity[$element] = [$activity[$element]];
 429                         }
 430
 431                         foreach ($activity[$element] as $receiver) {
 432                                 if (empty($receiver)) {
 433                                         continue;
 434                                 }
 435
 436                                 if (!empty($profile['followers']) && $receiver == $profile['followers'] && !empty($item_profile['followers'])) {
 437                                         $permissions[$element][] = $item_profile['followers'];
 438                                 } elseif (!in_array($receiver, $exclude)) {
 439                                         $permissions[$element][] = $receiver;
 440                                 }
 441                         }
 442                 }
 443                 return $permissions;
 444         }
 445
 446         /**
 447          * Creates an array of permissions from an item thread
 448          *
 449          * @param array   $item       Item array
 450          * @param boolean $blindcopy  addressing via "bcc" or "cc"?
 451          * @param integer $last_id    Last item id for adding receivers
 452          * @param boolean $forum_mode "true" means that we are sending content to a forum
 453          *
 454          * @return array with permission data
 455          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 456          * @throws \ImagickException
 457          */
 458         private static function createPermissionBlockForItem($item, $blindcopy, $last_id = 0, $forum_mode = false)
 459         {
 460                 if ($last_id == 0) {
 461                         $last_id = $item['id'];
 462                 }
 463
 464                 $always_bcc = false;
 465
 466                 // Check if we should always deliver our stuff via BCC
 467                 if (!empty($item['uid'])) {
 468                         $profile = User::getOwnerDataById($item['uid']);
 469                         if (!empty($profile)) {
 470                                 $always_bcc = $profile['hide-friends'];
 471                         }
 472                 }
 473
 474                 if (DI::config()->get('system', 'ap_always_bcc')) {
 475                         $always_bcc = true;
 476                 }
 477
 478                 if (self::isAnnounce($item) || DI::config()->get('debug', 'total_ap_delivery')) {
 479                         // Will be activated in a later step
 480                         $networks = Protocol::FEDERATED;
 481                 } else {
 482                         // For now only send to these contacts:
 483                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 484                 }
 485
 486                 $data = ['to' => [], 'cc' => [], 'bcc' => []];
 487
 488                 if ($item['gravity'] == GRAVITY_PARENT) {
 489                         $actor_profile = APContact::getByURL($item['owner-link']);
 490                 } else {
 491                         $actor_profile = APContact::getByURL($item['author-link']);
 492                 }
 493
 494                 $terms = Tag::getByURIId($item['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
 495
 496                 if ($item['private'] != Item::PRIVATE) {
 497                         // Directly mention the original author upon a quoted reshare.
 498                         // Else just ensure that the original author receives the reshare.
 499                         $announce = self::getAnnounceArray($item);
 500                         if (!empty($announce['comment'])) {
 501                                 $data['to'][] = $announce['actor']['url'];
 502                         } elseif (!empty($announce)) {
 503                                 $data['cc'][] = $announce['actor']['url'];
 504                         }
 505
 506                         $data = array_merge($data, self::fetchPermissionBlockFromConversation($item));
 507
 508                         // Check if the item is completely public or unlisted
 509                         if ($item['private'] == Item::PUBLIC) {
 510                                 $data['to'][] = ActivityPub::PUBLIC_COLLECTION;
 511                         } else {
 512                                 $data['cc'][] = ActivityPub::PUBLIC_COLLECTION;
 513                         }
 514
 515                         foreach ($terms as $term) {
 516                                 $profile = APContact::getByURL($term['url'], false);
 517                                 if (!empty($profile)) {
 518                                         $data['to'][] = $profile['url'];
 519                                 }
 520                         }
 521                 } else {
 522                         $receiver_list = Item::enumeratePermissions($item, true);
 523
 524                         foreach ($terms as $term) {
 525                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 526                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 527                                         $contact = DBA::selectFirst('contact', ['url', 'network', 'protocol'], ['id' => $cid]);
 528                                         if (!DBA::isResult($contact) || (!in_array($contact['network'], $networks) && ($contact['protocol'] != Protocol::ACTIVITYPUB))) {
 529                                                 continue;
 530                                         }
 531
 532                                         if (!empty($profile = APContact::getByURL($contact['url'], false))) {
 533                                                 $data['to'][] = $profile['url'];
 534                                         }
 535                                 }
 536                         }
 537
 538                         foreach ($receiver_list as $receiver) {
 539                                 $contact = DBA::selectFirst('contact', ['url', 'hidden', 'network', 'protocol'], ['id' => $receiver]);
 540                                 if (!DBA::isResult($contact) || (!in_array($contact['network'], $networks) && ($contact['protocol'] != Protocol::ACTIVITYPUB))) {
 541                                         continue;
 542                                 }
 543
 544                                 if (!empty($profile = APContact::getByURL($contact['url'], false))) {
 545                                         if ($contact['hidden'] || $always_bcc) {
 546                                                 $data['bcc'][] = $profile['url'];
 547                                         } else {
 548                                                 $data['cc'][] = $profile['url'];
 549                                         }
 550                                 }
 551                         }
 552                 }
 553
 554                 if (!empty($item['parent'])) {
 555                         $parents = Item::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']]);
 556                         while ($parent = Item::fetch($parents)) {
 557                                 if ($parent['gravity'] == GRAVITY_PARENT) {
 558                                         $profile = APContact::getByURL($parent['owner-link'], false);
 559                                         if (!empty($profile)) {
 560                                                 if ($item['gravity'] != GRAVITY_PARENT) {
 561                                                         // Comments to forums are directed to the forum
 562                                                         // But comments to forums aren't directed to the followers collection
 563                                                         // This rule is only valid when the actor isn't the forum.
 564                                                         // The forum needs to transmit their content to their followers.
 565                                                         if (($profile['type'] == 'Group') && ($profile['url'] != $actor_profile['url'])) {
 566                                                                 $data['to'][] = $profile['url'];
 567                                                         } else {
 568                                                                 $data['cc'][] = $profile['url'];
 569                                                                 if (($item['private'] != Item::PRIVATE) && !empty($actor_profile['followers'])) {
 570                                                                         $data['cc'][] = $actor_profile['followers'];
 571                                                                 }
 572                                                         }
 573                                                 } else {
 574                                                         // Public thread parent post always are directed to the followers
 575                                                         if (($item['private'] != Item::PRIVATE) && !$forum_mode) {
 576                                                                 $data['cc'][] = $actor_profile['followers'];
 577                                                         }
 578                                                 }
 579                                         }
 580                                 }
 581
 582                                 // Don't include data from future posts
 583                                 if ($parent['id'] >= $last_id) {
 584                                         continue;
 585                                 }
 586
 587                                 $profile = APContact::getByURL($parent['author-link'], false);
 588                                 if (!empty($profile)) {
 589                                         if (($profile['type'] == 'Group') || ($parent['uri'] == $item['thr-parent'])) {
 590                                                 $data['to'][] = $profile['url'];
 591                                         } else {
 592                                                 $data['cc'][] = $profile['url'];
 593                                         }
 594                                 }
 595                         }
 596                         DBA::close($parents);
 597                 }
 598
 599                 $data['to'] = array_unique($data['to']);
 600                 $data['cc'] = array_unique($data['cc']);
 601                 $data['bcc'] = array_unique($data['bcc']);
 602
 603                 if (($key = array_search($item['author-link'], $data['to'])) !== false) {
 604                         unset($data['to'][$key]);
 605                 }
 606
 607                 if (($key = array_search($item['author-link'], $data['cc'])) !== false) {
 608                         unset($data['cc'][$key]);
 609                 }
 610
 611                 if (($key = array_search($item['author-link'], $data['bcc'])) !== false) {
 612                         unset($data['bcc'][$key]);
 613                 }
 614
 615                 foreach ($data['to'] as $to) {
 616                         if (($key = array_search($to, $data['cc'])) !== false) {
 617                                 unset($data['cc'][$key]);
 618                         }
 619
 620                         if (($key = array_search($to, $data['bcc'])) !== false) {
 621                                 unset($data['bcc'][$key]);
 622                         }
 623                 }
 624
 625                 foreach ($data['cc'] as $cc) {
 626                         if (($key = array_search($cc, $data['bcc'])) !== false) {
 627                                 unset($data['bcc'][$key]);
 628                         }
 629                 }
 630
 631                 $receivers = ['to' => array_values($data['to']), 'cc' => array_values($data['cc']), 'bcc' => array_values($data['bcc'])];
 632
 633                 if (!$blindcopy) {
 634                         unset($receivers['bcc']);
 635                 }
 636
 637                 return $receivers;
 638         }
 639
 640         /**
 641          * Check if an inbox is archived
 642          *
 643          * @param string $url Inbox url
 644          *
 645          * @return boolean "true" if inbox is archived
 646          */
 647         private static function archivedInbox($url)
 648         {
 649                 return DBA::exists('inbox-status', ['url' => $url, 'archive' => true]);
 650         }
 651
 652         /**
 653          * Fetches a list of inboxes of followers of a given user
 654          *
 655          * @param integer $uid      User ID
 656          * @param boolean $personal fetch personal inboxes
 657          *
 658          * @return array of follower inboxes
 659          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 660          * @throws \ImagickException
 661          */
 662         public static function fetchTargetInboxesforUser($uid, $personal = false)
 663         {
 664                 $inboxes = [];
 665
 666                 $isforum = false;
 667
 668                 if (!empty($item['uid'])) {
 669                         $profile = User::getOwnerDataById($item['uid']);
 670                         if (!empty($profile)) {
 671                                 $isforum = $profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY;
 672                         }
 673                 }
 674
 675                 if (DI::config()->get('debug', 'total_ap_delivery')) {
 676                         // Will be activated in a later step
 677                         $networks = Protocol::FEDERATED;
 678                 } else {
 679                         // For now only send to these contacts:
 680                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 681                 }
 682
 683                 $condition = ['uid' => $uid, 'archive' => false, 'pending' => false];
 684
 685                 if (!empty($uid)) {
 686                         $condition['rel'] = [Contact::FOLLOWER, Contact::FRIEND];
 687                 }
 688
 689                 $contacts = DBA::select('contact', ['url', 'network', 'protocol'], $condition);
 690                 while ($contact = DBA::fetch($contacts)) {
 691                         if (Contact::isLocal($contact['url'])) {
 692                                 continue;
 693                         }
 694
 695                         if (!in_array($contact['network'], $networks) && ($contact['protocol'] != Protocol::ACTIVITYPUB)) {
 696                                 continue;
 697                         }
 698
 699                         if ($isforum && ($contact['dfrn'] == Protocol::DFRN)) {
 700                                 continue;
 701                         }
 702
 703                         if (Network::isUrlBlocked($contact['url'])) {
 704                                 continue;
 705                         }
 706
 707                         $profile = APContact::getByURL($contact['url'], false);
 708                         if (!empty($profile)) {
 709                                 if (empty($profile['sharedinbox']) || $personal) {
 710                                         $target = $profile['inbox'];
 711                                 } else {
 712                                         $target = $profile['sharedinbox'];
 713                                 }
 714                                 if (!self::archivedInbox($target)) {
 715                                         $inboxes[$target] = $target;
 716                                 }
 717                         }
 718                 }
 719                 DBA::close($contacts);
 720
 721                 return $inboxes;
 722         }
 723
 724         /**
 725          * Fetches an array of inboxes for the given item and user
 726          *
 727          * @param array   $item       Item array
 728          * @param integer $uid        User ID
 729          * @param boolean $personal   fetch personal inboxes
 730          * @param integer $last_id    Last item id for adding receivers
 731          * @param boolean $forum_mode "true" means that we are sending content to a forum
 732          * @return array with inboxes
 733          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 734          * @throws \ImagickException
 735          */
 736         public static function fetchTargetInboxes($item, $uid, $personal = false, $last_id = 0, $forum_mode = false)
 737         {
 738                 $permissions = self::createPermissionBlockForItem($item, true, $last_id, $forum_mode);
 739                 if (empty($permissions)) {
 740                         return [];
 741                 }
 742
 743                 $inboxes = [];
 744
 745                 if ($item['gravity'] == GRAVITY_ACTIVITY) {
 746                         $item_profile = APContact::getByURL($item['author-link'], false);
 747                 } else {
 748                         $item_profile = APContact::getByURL($item['owner-link'], false);
 749                 }
 750
 751                 if (empty($item_profile)) {
 752                         return [];
 753                 }
 754
 755                 $profile_uid = User::getIdForURL($item_profile['url']);
 756
 757                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 758                         if (empty($permissions[$element])) {
 759                                 continue;
 760                         }
 761
 762                         $blindcopy = in_array($element, ['bto', 'bcc']);
 763
 764                         foreach ($permissions[$element] as $receiver) {
 765                                 if (empty($receiver) || Network::isUrlBlocked($receiver)) {
 766                                         continue;
 767                                 }
 768
 769                                 if ($item_profile && ($receiver == $item_profile['followers']) && ($uid == $profile_uid)) {
 770                                         $inboxes = array_merge($inboxes, self::fetchTargetInboxesforUser($uid, $personal));
 771                                 } else {
 772                                         if (Contact::isLocal($receiver)) {
 773                                                 continue;
 774                                         }
 775
 776                                         $profile = APContact::getByURL($receiver, false);
 777                                         if (!empty($profile)) {
 778                                                 if (empty($profile['sharedinbox']) || $personal || $blindcopy) {
 779                                                         $target = $profile['inbox'];
 780                                                 } else {
 781                                                         $target = $profile['sharedinbox'];
 782                                                 }
 783                                                 if (!self::archivedInbox($target)) {
 784                                                         $inboxes[$target] = $target;
 785                                                 }
 786                                         }
 787                                 }
 788                         }
 789                 }
 790
 791                 return $inboxes;
 792         }
 793
 794         /**
 795          * Creates an array in the structure of the item table for a given mail id
 796          *
 797          * @param integer $mail_id
 798          *
 799          * @return array
 800          * @throws \Exception
 801          */
 802         public static function ItemArrayFromMail($mail_id)
 803         {
 804                 $mail = DBA::selectFirst('mail', [], ['id' => $mail_id]);
 805                 if (!DBA::isResult($mail)) {
 806                         return [];
 807                 }
 808
 809                 $mail['uri-id'] = ItemURI::insert(['uri' => $mail['uri'], 'guid' => $mail['guid']]);
 810
 811                 $reply = DBA::selectFirst('mail', ['uri'], ['parent-uri' => $mail['parent-uri'], 'reply' => false]);
 812
 813                 // Making the post more compatible for Mastodon by:
 814                 // - Making it a note and not an article (no title)
 815                 // - Moving the title into the "summary" field that is used as a "content warning"
 816                 $mail['body'] = '[abstract]' . $mail['title'] . "[/abstract]\n" . $mail['body'];
 817                 $mail['title'] = '';
 818
 819                 $mail['author-link'] = $mail['owner-link'] = $mail['from-url'];
 820                 $mail['allow_cid'] = '<'.$mail['contact-id'].'>';
 821                 $mail['allow_gid'] = '';
 822                 $mail['deny_cid'] = '';
 823                 $mail['deny_gid'] = '';
 824                 $mail['private'] = true;
 825                 $mail['deleted'] = false;
 826                 $mail['edited'] = $mail['created'];
 827                 $mail['plink'] = $mail['uri'];
 828                 $mail['thr-parent'] = $reply['uri'];
 829                 $mail['gravity'] = ($mail['reply'] ? GRAVITY_COMMENT: GRAVITY_PARENT);
 830
 831                 $mail['event-type'] = '';
 832                 $mail['attach'] = '';
 833
 834                 $mail['parent'] = 0;
 835
 836                 return $mail;
 837         }
 838
 839         /**
 840          * Creates an activity array for a given mail id
 841          *
 842          * @param integer $mail_id
 843          * @param boolean $object_mode Is the activity item is used inside another object?
 844          *
 845          * @return array of activity
 846          * @throws \Exception
 847          */
 848         public static function createActivityFromMail($mail_id, $object_mode = false)
 849         {
 850                 $mail = self::ItemArrayFromMail($mail_id);
 851                 if (empty($mail)) {
 852                         return [];
 853                 }
 854                 $object = self::createNote($mail);
 855
 856                 if (!$object_mode) {
 857                         $data = ['@context' => ActivityPub::CONTEXT];
 858                 } else {
 859                         $data = [];
 860                 }
 861
 862                 $data['id'] = $mail['uri'] . '/Create';
 863                 $data['type'] = 'Create';
 864                 $data['actor'] = $mail['author-link'];
 865                 $data['published'] = DateTimeFormat::utc($mail['created'] . '+00:00', DateTimeFormat::ATOM);
 866                 $data['instrument'] = self::getService();
 867                 $data = array_merge($data, self::createPermissionBlockForItem($mail, true));
 868
 869                 if (empty($data['to']) && !empty($data['cc'])) {
 870                         $data['to'] = $data['cc'];
 871                 }
 872
 873                 if (empty($data['to']) && !empty($data['bcc'])) {
 874                         $data['to'] = $data['bcc'];
 875                 }
 876
 877                 unset($data['cc']);
 878                 unset($data['bcc']);
 879
 880                 $object['to'] = $data['to'];
 881                 $object['tag'] = [['type' => 'Mention', 'href' => $object['to'][0], 'name' => '']];
 882
 883                 unset($object['cc']);
 884                 unset($object['bcc']);
 885
 886                 $data['directMessage'] = true;
 887
 888                 $data['object'] = $object;
 889
 890                 $owner = User::getOwnerDataById($mail['uid']);
 891
 892                 if (!$object_mode && !empty($owner)) {
 893                         return LDSignature::sign($data, $owner);
 894                 } else {
 895                         return $data;
 896                 }
 897         }
 898
 899         /**
 900          * Returns the activity type of a given item
 901          *
 902          * @param array $item
 903          *
 904          * @return string with activity type
 905          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 906          * @throws \ImagickException
 907          */
 908         private static function getTypeOfItem($item)
 909         {
 910                 $reshared = false;
 911
 912                 // Only check for a reshare, if it is a real reshare and no quoted reshare
 913                 if (strpos($item['body'], "[share") === 0) {
 914                         $announce = self::getAnnounceArray($item);
 915                         $reshared = !empty($announce);
 916                 }
 917
 918                 if ($reshared) {
 919                         $type = 'Announce';
 920                 } elseif ($item['verb'] == Activity::POST) {
 921                         if ($item['created'] == $item['edited']) {
 922                                 $type = 'Create';
 923                         } else {
 924                                 $type = 'Update';
 925                         }
 926                 } elseif ($item['verb'] == Activity::LIKE) {
 927                         $type = 'Like';
 928                 } elseif ($item['verb'] == Activity::DISLIKE) {
 929                         $type = 'Dislike';
 930                 } elseif ($item['verb'] == Activity::ATTEND) {
 931                         $type = 'Accept';
 932                 } elseif ($item['verb'] == Activity::ATTENDNO) {
 933                         $type = 'Reject';
 934                 } elseif ($item['verb'] == Activity::ATTENDMAYBE) {
 935                         $type = 'TentativeAccept';
 936                 } elseif ($item['verb'] == Activity::FOLLOW) {
 937                         $type = 'Follow';
 938                 } elseif ($item['verb'] == Activity::TAG) {
 939                         $type = 'Add';
 940                 } elseif ($item['verb'] == Activity::ANNOUNCE) {
 941                         $type = 'Announce';
 942                 } else {
 943                         $type = '';
 944                 }
 945
 946                 return $type;
 947         }
 948
 949         /**
 950          * Creates the activity or fetches it from the cache
 951          *
 952          * @param integer $item_id
 953          * @param boolean $force Force new cache entry
 954          *
 955          * @return array with the activity
 956          * @throws \Exception
 957          */
 958         public static function createCachedActivityFromItem($item_id, $force = false)
 959         {
 960                 $cachekey = 'APDelivery:createActivity:' . $item_id;
 961
 962                 if (!$force) {
 963                         $data = DI::cache()->get($cachekey);
 964                         if (!is_null($data)) {
 965                                 return $data;
 966                         }
 967                 }
 968
 969                 $data = self::createActivityFromItem($item_id);
 970
 971                 DI::cache()->set($cachekey, $data, Duration::QUARTER_HOUR);
 972                 return $data;
 973         }
 974
 975         /**
 976          * Creates an activity array for a given item id
 977          *
 978          * @param integer $item_id
 979          * @param boolean $object_mode Is the activity item is used inside another object?
 980          *
 981          * @return array of activity
 982          * @throws \Exception
 983          */
 984         public static function createActivityFromItem($item_id, $object_mode = false)
 985         {
 986                 Logger::info('Fetching activity', ['item' => $item_id]);
 987                 $item = Item::selectFirst([], ['id' => $item_id, 'parent-network' => Protocol::NATIVE_SUPPORT]);
 988                 if (!DBA::isResult($item)) {
 989                         return false;
 990                 }
 991
 992                 // In case of a forum post ensure to return the original post if author and forum are on the same machine
 993                 if (!empty($item['forum_mode'])) {
 994                         $author = Contact::getById($item['author-id'], ['nurl']);
 995                         if (!empty($author['nurl'])) {
 996                                 $self = Contact::selectFirst(['uid'], ['nurl' => $author['nurl'], 'self' => true]);
 997                                 if (!empty($self['uid'])) {
 998                                         $item = Item::selectFirst([], ['uri-id' => $item['uri-id'], 'uid' => $self['uid']]);
 999                                 }
1000                         }
1001                 }
1002
1003                 if (empty($type)) {
1004                         $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
1005                         $conversation = DBA::selectFirst('conversation', ['source'], $condition);
1006                         if (DBA::isResult($conversation)) {
1007                                 $data = json_decode($conversation['source'], true);
1008                                 if (!empty($data['type'])) {
1009                                         if (in_array($data['type'], ['Create', 'Update'])) {
1010                                                 if ($object_mode) {
1011                                                         unset($data['@context']);
1012                                                         unset($data['signature']);
1013                                                 }
1014                                                 Logger::info('Return stored conversation', ['item' => $item_id]);
1015                                                 return $data;
1016                                         } elseif (in_array('as:' . $data['type'], Receiver::CONTENT_TYPES)) {
1017                                                 if (!empty($data['@context'])) {
1018                                                         $context = $data['@context'];
1019                                                         unset($data['@context']);
1020                                                 }
1021                                                 unset($data['actor']);
1022                                                 $object = $data;
1023                                         }
1024                                 }
1025                         }
1026
1027                         $type = self::getTypeOfItem($item);
1028                 }
1029
1030                 if (!$object_mode) {
1031                         $data = ['@context' => $context ?? ActivityPub::CONTEXT];
1032
1033                         if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
1034                                 $type = 'Undo';
1035                         } elseif ($item['deleted']) {
1036                                 $type = 'Delete';
1037                         }
1038                 } else {
1039                         $data = [];
1040                 }
1041
1042                 if (($item['gravity'] == GRAVITY_ACTIVITY) && ($type != 'Undo')) {
1043                         $data['id'] = $item['uri'];
1044                 } else {
1045                         $data['id'] = $item['uri'] . '/' . $type;
1046                 }
1047
1048                 $data['type'] = $type;
1049
1050                 if (($type != 'Announce') || ($item['gravity'] != GRAVITY_PARENT)) {
1051                         $data['actor'] = $item['author-link'];
1052                 } else {
1053                         $data['actor'] = $item['owner-link'];
1054                 }
1055
1056                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1057
1058                 $data['instrument'] = self::getService();
1059
1060                 $data = array_merge($data, self::createPermissionBlockForItem($item, false));
1061
1062                 if (in_array($data['type'], ['Create', 'Update', 'Delete'])) {
1063                         $data['object'] = $object ?? self::createNote($item);
1064                 } elseif ($data['type'] == 'Add') {
1065                         $data = self::createAddTag($item, $data);
1066                 } elseif ($data['type'] == 'Announce') {
1067                         if ($item['verb'] == ACTIVITY::ANNOUNCE) {
1068                                 $data['object'] = $item['thr-parent'];
1069                         } else {
1070                                 $data = self::createAnnounce($item, $data);
1071                         }
1072                 } elseif ($data['type'] == 'Follow') {
1073                         $data['object'] = $item['parent-uri'];
1074                 } elseif ($data['type'] == 'Undo') {
1075                         $data['object'] = self::createActivityFromItem($item_id, true);
1076                 } else {
1077                         $data['diaspora:guid'] = $item['guid'];
1078                         if (!empty($item['signed_text'])) {
1079                                 $data['diaspora:like'] = $item['signed_text'];
1080                         }
1081                         $data['object'] = $item['thr-parent'];
1082                 }
1083
1084                 if (!empty($item['contact-uid'])) {
1085                         $uid = $item['contact-uid'];
1086                 } else {
1087                         $uid = $item['uid'];
1088                 }
1089
1090                 $owner = User::getOwnerDataById($uid);
1091
1092                 Logger::info('Fetched activity', ['item' => $item_id, 'uid' => $uid]);
1093
1094                 // We don't sign if we aren't the actor. This is important for relaying content especially for forums
1095                 if (!$object_mode && !empty($owner) && ($data['actor'] == $owner['url'])) {
1096                         return LDSignature::sign($data, $owner);
1097                 } else {
1098                         return $data;
1099                 }
1100
1101                 /// @todo Create "conversation" entry
1102         }
1103
1104         /**
1105          * Creates a location entry for a given item array
1106          *
1107          * @param array $item
1108          *
1109          * @return array with location array
1110          */
1111         private static function createLocation($item)
1112         {
1113                 $location = ['type' => 'Place'];
1114
1115                 if (!empty($item['location'])) {
1116                         $location['name'] = $item['location'];
1117                 }
1118
1119                 $coord = [];
1120
1121                 if (empty($item['coord'])) {
1122                         $coord = Map::getCoordinates($item['location']);
1123                 } else {
1124                         $coords = explode(' ', $item['coord']);
1125                         if (count($coords) == 2) {
1126                                 $coord = ['lat' => $coords[0], 'lon' => $coords[1]];
1127                         }
1128                 }
1129
1130                 if (!empty($coord['lat']) && !empty($coord['lon'])) {
1131                         $location['latitude'] = $coord['lat'];
1132                         $location['longitude'] = $coord['lon'];
1133                 }
1134
1135                 return $location;
1136         }
1137
1138         /**
1139          * Returns a tag array for a given item array
1140          *
1141          * @param array $item
1142          *
1143          * @return array of tags
1144          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1145          */
1146         private static function createTagList($item)
1147         {
1148                 $tags = [];
1149
1150                 $terms = Tag::getByURIId($item['uri-id'], [Tag::HASHTAG, Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1151                 foreach ($terms as $term) {
1152                         if ($term['type'] == Tag::HASHTAG) {
1153                                 $url = DI::baseUrl() . '/search?tag=' . urlencode($term['name']);
1154                                 $tags[] = ['type' => 'Hashtag', 'href' => $url, 'name' => '#' . $term['name']];
1155                         } else {
1156                                 $contact = Contact::getByURL($term['url'], false, ['addr']);
1157                                 if (empty($contact)) {
1158                                         continue;
1159                                 }
1160                                 if (!empty($contact['addr'])) {
1161                                         $mention = '@' . $contact['addr'];
1162                                 } else {
1163                                         $mention = '@' . $term['url'];
1164                                 }
1165
1166                                 $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
1167                         }
1168                 }
1169
1170                 $announce = self::getAnnounceArray($item);
1171                 // Mention the original author upon commented reshares
1172                 if (!empty($announce['comment'])) {
1173                         $tags[] = ['type' => 'Mention', 'href' => $announce['actor']['url'], 'name' => '@' . $announce['actor']['addr']];
1174                 }
1175
1176                 return $tags;
1177         }
1178
1179         /**
1180          * Adds attachment data to the JSON document
1181          *
1182          * @param array  $item Data of the item that is to be posted
1183          * @param string $type Object type
1184          *
1185          * @return array with attachment data
1186          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1187          */
1188         private static function createAttachmentList($item, $type)
1189         {
1190                 $attachments = [];
1191
1192                 // Currently deactivated, since it creates side effects on Mastodon and Pleroma.
1193                 // It will be reactivated, once this cleared.
1194                 /*
1195                 $attach_data = BBCode::getAttachmentData($item['body']);
1196                 if (!empty($attach_data['url'])) {
1197                         $attachment = ['type' => 'Page',
1198                                 'mediaType' => 'text/html',
1199                                 'url' => $attach_data['url']];
1200
1201                         if (!empty($attach_data['title'])) {
1202                                 $attachment['name'] = $attach_data['title'];
1203                         }
1204
1205                         if (!empty($attach_data['description'])) {
1206                                 $attachment['summary'] = $attach_data['description'];
1207                         }
1208
1209                         if (!empty($attach_data['image'])) {
1210                                 $imgdata = Images::getInfoFromURLCached($attach_data['image']);
1211                                 if ($imgdata) {
1212                                         $attachment['icon'] = ['type' => 'Image',
1213                                                 'mediaType' => $imgdata['mime'],
1214                                                 'width' => $imgdata[0],
1215                                                 'height' => $imgdata[1],
1216                                                 'url' => $attach_data['image']];
1217                                 }
1218                         }
1219
1220                         $attachments[] = $attachment;
1221                 }
1222                 */
1223                 $arr = explode('[/attach],', $item['attach']);
1224                 if (count($arr)) {
1225                         foreach ($arr as $r) {
1226                                 $matches = false;
1227                                 $cnt = preg_match('|\[attach\]href=\"(.*?)\" length=\"(.*?)\" type=\"(.*?)\" title=\"(.*?)\"|', $r, $matches);
1228                                 if ($cnt) {
1229                                         $attributes = ['type' => 'Document',
1230                                                         'mediaType' => $matches[3],
1231                                                         'url' => $matches[1],
1232                                                         'name' => null];
1233
1234                                         if (trim($matches[4]) != '') {
1235                                                 $attributes['name'] = trim($matches[4]);
1236                                         }
1237
1238                                         $attachments[] = $attributes;
1239                                 }
1240                         }
1241                 }
1242
1243                 if ($type != 'Note') {
1244                         return $attachments;
1245                 }
1246
1247                 // Simplify image codes
1248                 $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $item['body']);
1249
1250                 // Grab all pictures without alternative descriptions and create attachments out of them
1251                 if (preg_match_all("/\[img\]([^\[\]]*)\[\/img\]/Usi", $body, $pictures)) {
1252                         foreach ($pictures[1] as $picture) {
1253                                 $imgdata = Images::getInfoFromURLCached($picture);
1254                                 if ($imgdata) {
1255                                         $attachments[] = ['type' => 'Document',
1256                                                 'mediaType' => $imgdata['mime'],
1257                                                 'url' => $picture,
1258                                                 'name' => null];
1259                                 }
1260                         }
1261                 }
1262
1263                 // Grab all pictures with alternative description and create attachments out of them
1264                 if (preg_match_all("/\[img=([^\[\]]*)\]([^\[\]]*)\[\/img\]/Usi", $body, $pictures, PREG_SET_ORDER)) {
1265                         foreach ($pictures as $picture) {
1266                                 $imgdata = Images::getInfoFromURLCached($picture[1]);
1267                                 if ($imgdata) {
1268                                         $attachments[] = ['type' => 'Document',
1269                                                 'mediaType' => $imgdata['mime'],
1270                                                 'url' => $picture[1],
1271                                                 'name' => $picture[2]];
1272                                 }
1273                         }
1274                 }
1275
1276                 return $attachments;
1277         }
1278
1279         /**
1280          * Callback function to replace a Friendica style mention in a mention that is used on AP
1281          *
1282          * @param array $match Matching values for the callback
1283          * @return string Replaced mention
1284          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1285          */
1286         private static function mentionCallback($match)
1287         {
1288                 if (empty($match[1])) {
1289                         return '';
1290                 }
1291
1292                 $data = Contact::getByURL($match[1], false, ['url', 'nick']);
1293                 if (empty($data['nick'])) {
1294                         return $match[0];
1295                 }
1296
1297                 return '@[url=' . $data['url'] . ']' . $data['nick'] . '[/url]';
1298         }
1299
1300         /**
1301          * Remove image elements since they are added as attachment
1302          *
1303          * @param string $body
1304          *
1305          * @return string with removed images
1306          */
1307         private static function removePictures($body)
1308         {
1309                 // Simplify image codes
1310                 $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $body);
1311                 $body = preg_replace("/\[img\=(.*?)\](.*?)\[\/img\]/ism", '[img]$1[/img]', $body);
1312
1313                 // Now remove local links
1314                 $body = preg_replace_callback(
1315                         '/\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]/Usi',
1316                         function ($match) {
1317                                 // We remove the link when it is a link to a local photo page
1318                                 if (Photo::isLocalPage($match[1])) {
1319                                         return '';
1320                                 }
1321                                 // otherwise we just return the link
1322                                 return '[url]' . $match[1] . '[/url]';
1323                         },
1324                         $body
1325                 );
1326
1327                 // Remove all pictures
1328                 $body = preg_replace("/\[img\]([^\[\]]*)\[\/img\]/Usi", '', $body);
1329
1330                 return $body;
1331         }
1332
1333         /**
1334          * Fetches the "context" value for a givem item array from the "conversation" table
1335          *
1336          * @param array $item
1337          *
1338          * @return string with context url
1339          * @throws \Exception
1340          */
1341         private static function fetchContextURLForItem($item)
1342         {
1343                 $conversation = DBA::selectFirst('conversation', ['conversation-href', 'conversation-uri'], ['item-uri' => $item['parent-uri']]);
1344                 if (DBA::isResult($conversation) && !empty($conversation['conversation-href'])) {
1345                         $context_uri = $conversation['conversation-href'];
1346                 } elseif (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
1347                         $context_uri = $conversation['conversation-uri'];
1348                 } else {
1349                         $context_uri = $item['parent-uri'] . '#context';
1350                 }
1351                 return $context_uri;
1352         }
1353
1354         /**
1355          * Returns if the post contains sensitive content ("nsfw")
1356          *
1357          * @param integer $uri_id
1358          *
1359          * @return boolean
1360          * @throws \Exception
1361          */
1362         private static function isSensitive($uri_id)
1363         {
1364                 return DBA::exists('tag-view', ['uri-id' => $uri_id, 'name' => 'nsfw']);
1365         }
1366
1367         /**
1368          * Creates event data
1369          *
1370          * @param array $item
1371          *
1372          * @return array with the event data
1373          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1374          */
1375         public static function createEvent($item)
1376         {
1377                 $event = [];
1378                 $event['name'] = $item['event-summary'];
1379                 $event['content'] = BBCode::convert($item['event-desc'], false, BBCode::ACTIVITYPUB);
1380                 $event['startTime'] = DateTimeFormat::utc($item['event-start'] . '+00:00', DateTimeFormat::ATOM);
1381
1382                 if (!$item['event-nofinish']) {
1383                         $event['endTime'] = DateTimeFormat::utc($item['event-finish'] . '+00:00', DateTimeFormat::ATOM);
1384                 }
1385
1386                 if (!empty($item['event-location'])) {
1387                         $item['location'] = $item['event-location'];
1388                         $event['location'] = self::createLocation($item);
1389                 }
1390
1391                 return $event;
1392         }
1393
1394         /**
1395          * Creates a note/article object array
1396          *
1397          * @param array $item
1398          *
1399          * @return array with the object data
1400          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1401          * @throws \ImagickException
1402          */
1403         public static function createNote($item)
1404         {
1405                 if (empty($item)) {
1406                         return [];
1407                 }
1408
1409                 if ($item['event-type'] == 'event') {
1410                         $type = 'Event';
1411                 } elseif (!empty($item['title'])) {
1412                         $type = 'Article';
1413                 } else {
1414                         $type = 'Note';
1415                 }
1416
1417                 if ($item['deleted']) {
1418                         $type = 'Tombstone';
1419                 }
1420
1421                 $data = [];
1422                 $data['id'] = $item['uri'];
1423                 $data['type'] = $type;
1424
1425                 if ($item['deleted']) {
1426                         return $data;
1427                 }
1428
1429                 $data['summary'] = BBCode::toPlaintext(BBCode::getAbstract($item['body'], Protocol::ACTIVITYPUB));
1430
1431                 if ($item['uri'] != $item['thr-parent']) {
1432                         $data['inReplyTo'] = $item['thr-parent'];
1433                 } else {
1434                         $data['inReplyTo'] = null;
1435                 }
1436
1437                 $data['diaspora:guid'] = $item['guid'];
1438                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1439
1440                 if ($item['created'] != $item['edited']) {
1441                         $data['updated'] = DateTimeFormat::utc($item['edited'] . '+00:00', DateTimeFormat::ATOM);
1442                 }
1443
1444                 $data['url'] = $item['plink'];
1445                 $data['attributedTo'] = $item['author-link'];
1446                 $data['sensitive'] = self::isSensitive($item['uri-id']);
1447                 $data['context'] = self::fetchContextURLForItem($item);
1448
1449                 if (!empty($item['title'])) {
1450                         $data['name'] = BBCode::toPlaintext($item['title'], false);
1451                 }
1452
1453                 $permission_block = self::createPermissionBlockForItem($item, false);
1454
1455                 $body = $item['body'];
1456
1457                 if (empty($item['uid']) || !Feature::isEnabled($item['uid'], 'explicit_mentions')) {
1458                         $body = self::prependMentions($body, $item['uri-id']);
1459                 }
1460
1461                 if ($type == 'Note') {
1462                         $body = self::removePictures($body);
1463                 } elseif (($type == 'Article') && empty($data['summary'])) {
1464                         $data['summary'] = BBCode::toPlaintext(Plaintext::shorten(self::removePictures($body), 1000));
1465                 }
1466
1467                 if ($type == 'Event') {
1468                         $data = array_merge($data, self::createEvent($item));
1469                 } else {
1470                         $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1471                         $body = preg_replace_callback($regexp, ['self', 'mentionCallback'], $body);
1472
1473                         $data['content'] = BBCode::convert($body, false, BBCode::ACTIVITYPUB);
1474                 }
1475
1476                 // The regular "content" field does contain a minimized HTML. This is done since systems like
1477                 // Mastodon has got problems with - for example - embedded pictures.
1478                 // The contentMap does contain the unmodified HTML.
1479                 $language = self::getLanguage($item);
1480                 if (!empty($language)) {
1481                         $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1482                         $richbody = preg_replace_callback($regexp, ['self', 'mentionCallback'], $item['body']);
1483                         $richbody = BBCode::removeAttachment($richbody);
1484
1485                         $data['contentMap'][$language] = BBCode::convert($richbody, false);
1486                 }
1487
1488                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
1489
1490                 if (!empty($item['signed_text']) && ($item['uri'] != $item['thr-parent'])) {
1491                         $data['diaspora:comment'] = $item['signed_text'];
1492                 }
1493
1494                 $data['attachment'] = self::createAttachmentList($item, $type);
1495                 $data['tag'] = self::createTagList($item);
1496
1497                 if (empty($data['location']) && (!empty($item['coord']) || !empty($item['location']))) {
1498                         $data['location'] = self::createLocation($item);
1499                 }
1500
1501                 if (!empty($item['app'])) {
1502                         $data['generator'] = ['type' => 'Application', 'name' => $item['app']];
1503                 }
1504
1505                 $data = array_merge($data, $permission_block);
1506
1507                 return $data;
1508         }
1509
1510         /**
1511          * Fetches the language from the post, the user or the system.
1512          *
1513          * @param array $item
1514          *
1515          * @return string language string
1516          */
1517         private static function getLanguage(array $item)
1518         {
1519                 // Try to fetch the language from the post itself
1520                 if (!empty($item['language'])) {
1521                         $languages = array_keys(json_decode($item['language'], true));
1522                         if (!empty($languages[0])) {
1523                                 return $languages[0];
1524                         }
1525                 }
1526
1527                 // Otherwise use the user's language
1528                 if (!empty($item['uid'])) {
1529                         $user = DBA::selectFirst('user', ['language'], ['uid' => $item['uid']]);
1530                         if (!empty($user['language'])) {
1531                                 return $user['language'];
1532                         }
1533                 }
1534
1535                 // And finally just use the system language
1536                 return DI::config()->get('system', 'language');
1537         }
1538
1539         /**
1540          * Creates an an "add tag" entry
1541          *
1542          * @param array $item
1543          * @param array $data activity data
1544          *
1545          * @return array with activity data for adding tags
1546          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1547          * @throws \ImagickException
1548          */
1549         private static function createAddTag($item, $data)
1550         {
1551                 $object = XML::parseString($item['object']);
1552                 $target = XML::parseString($item["target"]);
1553
1554                 $data['diaspora:guid'] = $item['guid'];
1555                 $data['actor'] = $item['author-link'];
1556                 $data['target'] = (string)$target->id;
1557                 $data['summary'] = BBCode::toPlaintext($item['body']);
1558                 $data['object'] = ['id' => (string)$object->id, 'type' => 'tag', 'name' => (string)$object->title, 'content' => (string)$object->content];
1559
1560                 return $data;
1561         }
1562
1563         /**
1564          * Creates an announce object entry
1565          *
1566          * @param array $item
1567          * @param array $data activity data
1568          *
1569          * @return array with activity data
1570          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1571          * @throws \ImagickException
1572          */
1573         private static function createAnnounce($item, $data)
1574         {
1575                 $orig_body = $item['body'];
1576                 $announce = self::getAnnounceArray($item);
1577                 if (empty($announce)) {
1578                         $data['type'] = 'Create';
1579                         $data['object'] = self::createNote($item);
1580                         return $data;
1581                 }
1582
1583                 if (empty($announce['comment'])) {
1584                         // Pure announce, without a quote
1585                         $data['type'] = 'Announce';
1586                         $data['object'] = $announce['object']['uri'];
1587                         return $data;
1588                 }
1589
1590                 // Quote
1591                 $data['type'] = 'Create';
1592                 $item['body'] = $announce['comment'] . "\n" . $announce['object']['plink'];
1593                 $data['object'] = self::createNote($item);
1594
1595                 /// @todo Finally descide how to implement this in AP. This is a possible way:
1596                 $data['object']['attachment'][] = self::createNote($announce['object']);
1597
1598                 $data['object']['source']['content'] = $orig_body;
1599                 return $data;
1600         }
1601
1602         /**
1603          * Return announce related data if the item is an annunce
1604          *
1605          * @param array $item
1606          *
1607          * @return array
1608          */
1609         public static function getAnnounceArray($item)
1610         {
1611                 $reshared = Item::getShareArray($item);
1612                 if (empty($reshared['guid'])) {
1613                         return [];
1614                 }
1615
1616                 $reshared_item = Item::selectFirst([], ['guid' => $reshared['guid']]);
1617                 if (!DBA::isResult($reshared_item)) {
1618                         return [];
1619                 }
1620
1621                 if (!in_array($reshared_item['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN])) {
1622                         return [];
1623                 }
1624
1625                 $profile = APContact::getByURL($reshared_item['author-link'], false);
1626                 if (empty($profile)) {
1627                         return [];
1628                 }
1629
1630                 return ['object' => $reshared_item, 'actor' => $profile, 'comment' => $reshared['comment']];
1631         }
1632
1633         /**
1634          * Checks if the provided item array is an announce
1635          *
1636          * @param array $item
1637          *
1638          * @return boolean
1639          */
1640         public static function isAnnounce($item)
1641         {
1642                 if (!empty($item['verb']) && ($item['verb'] == Activity::ANNOUNCE)) {
1643                         return true;
1644                 }
1645
1646                 $announce = self::getAnnounceArray($item);
1647                 if (empty($announce)) {
1648                         return false;
1649                 }
1650
1651                 return empty($announce['comment']);
1652         }
1653
1654         /**
1655          * Creates an activity id for a given contact id
1656          *
1657          * @param integer $cid Contact ID of target
1658          *
1659          * @return bool|string activity id
1660          */
1661         public static function activityIDFromContact($cid)
1662         {
1663                 $contact = DBA::selectFirst('contact', ['uid', 'id', 'created'], ['id' => $cid]);
1664                 if (!DBA::isResult($contact)) {
1665                         return false;
1666                 }
1667
1668                 $hash = hash('ripemd128', $contact['uid'].'-'.$contact['id'].'-'.$contact['created']);
1669                 $uuid = substr($hash, 0, 8). '-' . substr($hash, 8, 4) . '-' . substr($hash, 12, 4) . '-' . substr($hash, 16, 4) . '-' . substr($hash, 20, 12);
1670                 return DI::baseUrl() . '/activity/' . $uuid;
1671         }
1672
1673         /**
1674          * Transmits a contact suggestion to a given inbox
1675          *
1676          * @param integer $uid           User ID
1677          * @param string  $inbox         Target inbox
1678          * @param integer $suggestion_id Suggestion ID
1679          *
1680          * @return boolean was the transmission successful?
1681          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1682          */
1683         public static function sendContactSuggestion($uid, $inbox, $suggestion_id)
1684         {
1685                 $owner = User::getOwnerDataById($uid);
1686
1687                 $suggestion = DI::fsuggest()->getById($suggestion_id);
1688
1689                 $data = ['@context' => ActivityPub::CONTEXT,
1690                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1691                         'type' => 'Announce',
1692                         'actor' => $owner['url'],
1693                         'object' => $suggestion->url,
1694                         'content' => $suggestion->note,
1695                         'instrument' => self::getService(),
1696                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1697                         'cc' => []];
1698
1699                 $signed = LDSignature::sign($data, $owner);
1700
1701                 Logger::log('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1702                 return HTTPSignature::transmit($signed, $inbox, $uid);
1703         }
1704
1705         /**
1706          * Transmits a profile relocation to a given inbox
1707          *
1708          * @param integer $uid   User ID
1709          * @param string  $inbox Target inbox
1710          *
1711          * @return boolean was the transmission successful?
1712          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1713          */
1714         public static function sendProfileRelocation($uid, $inbox)
1715         {
1716                 $owner = User::getOwnerDataById($uid);
1717
1718                 $data = ['@context' => ActivityPub::CONTEXT,
1719                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1720                         'type' => 'dfrn:relocate',
1721                         'actor' => $owner['url'],
1722                         'object' => $owner['url'],
1723                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1724                         'instrument' => self::getService(),
1725                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1726                         'cc' => []];
1727
1728                 $signed = LDSignature::sign($data, $owner);
1729
1730                 Logger::log('Deliver profile relocation for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1731                 return HTTPSignature::transmit($signed, $inbox, $uid);
1732         }
1733
1734         /**
1735          * Transmits a profile deletion to a given inbox
1736          *
1737          * @param integer $uid   User ID
1738          * @param string  $inbox Target inbox
1739          *
1740          * @return boolean was the transmission successful?
1741          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1742          */
1743         public static function sendProfileDeletion($uid, $inbox)
1744         {
1745                 $owner = User::getOwnerDataById($uid);
1746
1747                 if (empty($owner)) {
1748                         Logger::error('No owner data found, the deletion message cannot be processed.', ['user' => $uid]);
1749                         return false;
1750                 }
1751
1752                 if (empty($owner['uprvkey'])) {
1753                         Logger::error('No private key for owner found, the deletion message cannot be processed.', ['user' => $uid]);
1754                         return false;
1755                 }
1756
1757                 $data = ['@context' => ActivityPub::CONTEXT,
1758                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1759                         'type' => 'Delete',
1760                         'actor' => $owner['url'],
1761                         'object' => $owner['url'],
1762                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1763                         'instrument' => self::getService(),
1764                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1765                         'cc' => []];
1766
1767                 $signed = LDSignature::sign($data, $owner);
1768
1769                 Logger::log('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1770                 return HTTPSignature::transmit($signed, $inbox, $uid);
1771         }
1772
1773         /**
1774          * Transmits a profile change to a given inbox
1775          *
1776          * @param integer $uid   User ID
1777          * @param string  $inbox Target inbox
1778          *
1779          * @return boolean was the transmission successful?
1780          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1781          * @throws \ImagickException
1782          */
1783         public static function sendProfileUpdate($uid, $inbox)
1784         {
1785                 $owner = User::getOwnerDataById($uid);
1786                 $profile = APContact::getByURL($owner['url']);
1787
1788                 $data = ['@context' => ActivityPub::CONTEXT,
1789                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1790                         'type' => 'Update',
1791                         'actor' => $owner['url'],
1792                         'object' => self::getProfile($uid),
1793                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1794                         'instrument' => self::getService(),
1795                         'to' => [$profile['followers']],
1796                         'cc' => []];
1797
1798                 $signed = LDSignature::sign($data, $owner);
1799
1800                 Logger::log('Deliver profile update for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1801                 return HTTPSignature::transmit($signed, $inbox, $uid);
1802         }
1803
1804         /**
1805          * Transmits a given activity to a target
1806          *
1807          * @param string  $activity Type name
1808          * @param string  $target   Target profile
1809          * @param integer $uid      User ID
1810          * @return bool
1811          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1812          * @throws \ImagickException
1813          * @throws \Exception
1814          */
1815         public static function sendActivity($activity, $target, $uid, $id = '')
1816         {
1817                 $profile = APContact::getByURL($target);
1818                 if (empty($profile['inbox'])) {
1819                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1820                         return;
1821                 }
1822
1823                 $owner = User::getOwnerDataById($uid);
1824
1825                 if (empty($id)) {
1826                         $id = DI::baseUrl() . '/activity/' . System::createGUID();
1827                 }
1828
1829                 $data = ['@context' => ActivityPub::CONTEXT,
1830                         'id' => $id,
1831                         'type' => $activity,
1832                         'actor' => $owner['url'],
1833                         'object' => $profile['url'],
1834                         'instrument' => self::getService(),
1835                         'to' => [$profile['url']]];
1836
1837                 Logger::log('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid, Logger::DEBUG);
1838
1839                 $signed = LDSignature::sign($data, $owner);
1840                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1841         }
1842
1843         /**
1844          * Transmits a "follow object" activity to a target
1845          * This is a preparation for sending automated "follow" requests when receiving "Announce" messages
1846          *
1847          * @param string  $object Object URL
1848          * @param string  $target Target profile
1849          * @param integer $uid    User ID
1850          * @return bool
1851          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1852          * @throws \ImagickException
1853          * @throws \Exception
1854          */
1855         public static function sendFollowObject($object, $target, $uid = 0)
1856         {
1857                 $profile = APContact::getByURL($target);
1858                 if (empty($profile['inbox'])) {
1859                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1860                         return;
1861                 }
1862
1863                 if (empty($uid)) {
1864                         // Fetch the list of administrators
1865                         $admin_mail = explode(',', str_replace(' ', '', DI::config()->get('config', 'admin_email')));
1866
1867                         // We need to use some user as a sender. It doesn't care who it will send. We will use an administrator account.
1868                         $condition = ['verified' => true, 'blocked' => false, 'account_removed' => false, 'account_expired' => false, 'email' => $admin_mail];
1869                         $first_user = DBA::selectFirst('user', ['uid'], $condition);
1870                         $uid = $first_user['uid'];
1871                 }
1872
1873                 $condition = ['verb' => Activity::FOLLOW, 'uid' => 0, 'parent-uri' => $object,
1874                         'author-id' => Contact::getPublicIdByUserId($uid)];
1875                 if (Item::exists($condition)) {
1876                         Logger::log('Follow for ' . $object . ' for user ' . $uid . ' does already exist.', Logger::DEBUG);
1877                         return false;
1878                 }
1879
1880                 $owner = User::getOwnerDataById($uid);
1881
1882                 $data = ['@context' => ActivityPub::CONTEXT,
1883                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1884                         'type' => 'Follow',
1885                         'actor' => $owner['url'],
1886                         'object' => $object,
1887                         'instrument' => self::getService(),
1888                         'to' => [$profile['url']]];
1889
1890                 Logger::log('Sending follow ' . $object . ' to ' . $target . ' for user ' . $uid, Logger::DEBUG);
1891
1892                 $signed = LDSignature::sign($data, $owner);
1893                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1894         }
1895
1896         /**
1897          * Transmit a message that the contact request had been accepted
1898          *
1899          * @param string  $target Target profile
1900          * @param         $id
1901          * @param integer $uid    User ID
1902          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1903          * @throws \ImagickException
1904          */
1905         public static function sendContactAccept($target, $id, $uid)
1906         {
1907                 $profile = APContact::getByURL($target);
1908                 if (empty($profile['inbox'])) {
1909                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1910                         return;
1911                 }
1912
1913                 $owner = User::getOwnerDataById($uid);
1914                 $data = ['@context' => ActivityPub::CONTEXT,
1915                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1916                         'type' => 'Accept',
1917                         'actor' => $owner['url'],
1918                         'object' => [
1919                                 'id' => (string)$id,
1920                                 'type' => 'Follow',
1921                                 'actor' => $profile['url'],
1922                                 'object' => $owner['url']
1923                         ],
1924                         'instrument' => self::getService(),
1925                         'to' => [$profile['url']]];
1926
1927                 Logger::debug('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id);
1928
1929                 $signed = LDSignature::sign($data, $owner);
1930                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1931         }
1932
1933         /**
1934          * Reject a contact request or terminates the contact relation
1935          *
1936          * @param string  $target Target profile
1937          * @param         $id
1938          * @param integer $uid    User ID
1939          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1940          * @throws \ImagickException
1941          */
1942         public static function sendContactReject($target, $id, $uid)
1943         {
1944                 $profile = APContact::getByURL($target);
1945                 if (empty($profile['inbox'])) {
1946                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1947                         return;
1948                 }
1949
1950                 $owner = User::getOwnerDataById($uid);
1951                 $data = ['@context' => ActivityPub::CONTEXT,
1952                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1953                         'type' => 'Reject',
1954                         'actor' => $owner['url'],
1955                         'object' => [
1956                                 'id' => (string)$id,
1957                                 'type' => 'Follow',
1958                                 'actor' => $profile['url'],
1959                                 'object' => $owner['url']
1960                         ],
1961                         'instrument' => self::getService(),
1962                         'to' => [$profile['url']]];
1963
1964                 Logger::debug('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id);
1965
1966                 $signed = LDSignature::sign($data, $owner);
1967                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1968         }
1969
1970         /**
1971          * Transmits a message that we don't want to follow this contact anymore
1972          *
1973          * @param string  $target Target profile
1974          * @param integer $uid    User ID
1975          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1976          * @throws \ImagickException
1977          * @throws \Exception
1978          * @return bool success
1979          */
1980         public static function sendContactUndo($target, $cid, $uid)
1981         {
1982                 $profile = APContact::getByURL($target);
1983                 if (empty($profile['inbox'])) {
1984                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1985                         return false;
1986                 }
1987
1988                 $object_id = self::activityIDFromContact($cid);
1989                 if (empty($object_id)) {
1990                         return false;
1991                 }
1992
1993                 $id = DI::baseUrl() . '/activity/' . System::createGUID();
1994
1995                 $owner = User::getOwnerDataById($uid);
1996                 $data = ['@context' => ActivityPub::CONTEXT,
1997                         'id' => $id,
1998                         'type' => 'Undo',
1999                         'actor' => $owner['url'],
2000                         'object' => ['id' => $object_id, 'type' => 'Follow',
2001                                 'actor' => $owner['url'],
2002                                 'object' => $profile['url']],
2003                         'instrument' => self::getService(),
2004                         'to' => [$profile['url']]];
2005
2006                 Logger::log('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id, Logger::DEBUG);
2007
2008                 $signed = LDSignature::sign($data, $owner);
2009                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2010         }
2011
2012         private static function prependMentions($body, int $uriid)
2013         {
2014                 $mentions = [];
2015
2016                 foreach (Tag::getByURIId($uriid, [Tag::IMPLICIT_MENTION]) as $tag) {
2017                         $profile = Contact::getByURL($tag['url'], false, ['addr', 'contact-type', 'nick']);
2018                         if (!empty($profile['addr'])
2019                                 && $profile['contact-type'] != Contact::TYPE_COMMUNITY
2020                                 && !strstr($body, $profile['addr'])
2021                                 && !strstr($body, $tag['url'])
2022                         ) {
2023                                 $mentions[] = '@[url=' . $tag['url'] . ']' . $profile['nick'] . '[/url]';
2024                         }
2025                 }
2026
2027                 $mentions[] = $body;
2028
2029                 return implode(' ', $mentions);
2030         }
2031 }