src/Protocol/ActivityPub/Transmitter.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2021, the Friendica project
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol\ActivityPub;
  23
  24 use Friendica\Content\Feature;
  25 use Friendica\Content\Text\BBCode;
  26 use Friendica\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\GServer;
  37 use Friendica\Model\Item;
  38 use Friendica\Model\ItemURI;
  39 use Friendica\Model\Profile;
  40 use Friendica\Model\Photo;
  41 use Friendica\Model\Post;
  42 use Friendica\Model\Tag;
  43 use Friendica\Model\User;
  44 use Friendica\Protocol\Activity;
  45 use Friendica\Protocol\ActivityPub;
  46 use Friendica\Protocol\Relay;
  47 use Friendica\Util\DateTimeFormat;
  48 use Friendica\Util\HTTPSignature;
  49 use Friendica\Util\JsonLD;
  50 use Friendica\Util\LDSignature;
  51 use Friendica\Util\Map;
  52 use Friendica\Util\Network;
  53 use Friendica\Util\XML;
  54
  55 /**
  56  * ActivityPub Transmitter Protocol class
  57  *
  58  * To-Do:
  59  * @todo Undo Announce
  60  */
  61 class Transmitter
  62 {
  63         /**
  64          * Add relay servers to the list of inboxes
  65          *
  66          * @param array $inboxes
  67          * @return array inboxes with added relay servers
  68          */
  69         public static function addRelayServerInboxes(array $inboxes = [])
  70         {
  71                 foreach (Relay::getList(['inbox']) as $contact) {
  72                         $inboxes[$contact['inbox']] = $contact['inbox'];
  73                 }
  74
  75                 return $inboxes;
  76         }
  77
  78         /**
  79          * Add relay servers to the list of inboxes
  80          *
  81          * @param array $inboxes
  82          * @return array inboxes with added relay servers
  83          */
  84         public static function addRelayServerInboxesForItem(int $item_id, array $inboxes = [])
  85         {
  86                 $item = Post::selectFirst(['uid'], ['id' => $item_id]);
  87                 if (empty($item)) {
  88                         return $inboxes;
  89                 }
  90
  91                 $relays = Relay::getDirectRelayList($item_id);
  92                 if (empty($relays)) {
  93                         return $inboxes;
  94                 }
  95
  96                 foreach ($relays as $relay) {
  97                         $contact = Contact::getByURLForUser($relay['url'], $item['uid'], false, ['id']);
  98                         $inboxes[$relay['batch']][] = $contact['id'] ?? 0;
  99                 }
 100                 return $inboxes;
 101         }
 102
 103         /**
 104          * Subscribe to a relay
 105          *
 106          * @param string $url Subscribe actor url
 107          * @return bool success
 108          */
 109         public static function sendRelayFollow(string $url)
 110         {
 111                 $contact = Contact::getByURL($url);
 112                 if (empty($contact)) {
 113                         return false;
 114                 }
 115
 116                 $activity_id = ActivityPub\Transmitter::activityIDFromContact($contact['id']);
 117                 $success = ActivityPub\Transmitter::sendActivity('Follow', $url, 0, $activity_id);
 118                 if ($success) {
 119                         DBA::update('contact', ['rel' => Contact::FRIEND], ['id' => $contact['id']]);
 120                 }
 121
 122                 return $success;
 123         }
 124
 125         /**
 126          * Unsubscribe from a relay
 127          *
 128          * @param string $url   Subscribe actor url
 129          * @param bool   $force Set the relay status as non follower even if unsubscribe hadn't worked
 130          * @return bool success
 131          */
 132         public static function sendRelayUndoFollow(string $url, bool $force = false)
 133         {
 134                 $contact = Contact::getByURL($url);
 135                 if (empty($contact)) {
 136                         return false;
 137                 }
 138
 139                 $success = self::sendContactUndo($url, $contact['id'], 0);
 140                 if ($success || $force) {
 141                         DBA::update('contact', ['rel' => Contact::NOTHING], ['id' => $contact['id']]);
 142                 }
 143
 144                 return $success;
 145         }
 146
 147         /**
 148          * Collects a list of contacts of the given owner
 149          *
 150          * @param array     $owner  Owner array
 151          * @param int|array $rel    The relevant value(s) contact.rel should match
 152          * @param string    $module The name of the relevant AP endpoint module (followers|following)
 153          * @param integer   $page   Page number
 154          *
 155          * @return array of owners
 156          * @throws \Exception
 157          */
 158         public static function getContacts($owner, $rel, $module, $page = null)
 159         {
 160                 $parameters = [
 161                         'rel' => $rel,
 162                         'uid' => $owner['uid'],
 163                         'self' => false,
 164                         'deleted' => false,
 165                         'hidden' => false,
 166                         'archive' => false,
 167                         'pending' => false,
 168                         'blocked' => false,
 169                 ];
 170                 $condition = DBA::buildCondition($parameters);
 171
 172                 $sql = "SELECT COUNT(*) as `count`
 173                         FROM `contact`
 174                         JOIN `apcontact` ON `apcontact`.`url` = `contact`.`url`
 175                         " . $condition;
 176
 177                 $contacts = DBA::fetchFirst($sql, ...$parameters);
 178
 179                 $modulePath = '/' . $module . '/';
 180
 181                 $data = ['@context' => ActivityPub::CONTEXT];
 182                 $data['id'] = DI::baseUrl() . $modulePath . $owner['nickname'];
 183                 $data['type'] = 'OrderedCollection';
 184                 $data['totalItems'] = $contacts['count'];
 185
 186                 // When we hide our friends we will only show the pure number but don't allow more.
 187                 $profile = Profile::getByUID($owner['uid']);
 188                 if (!empty($profile['hide-friends'])) {
 189                         return $data;
 190                 }
 191
 192                 if (empty($page)) {
 193                         $data['first'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=1';
 194                 } else {
 195                         $data['type'] = 'OrderedCollectionPage';
 196                         $list = [];
 197
 198                         $sql = "SELECT `contact`.`url`
 199                                 FROM `contact`
 200                                 JOIN `apcontact` ON `apcontact`.`url` = `contact`.`url`
 201                                 " . $condition . "
 202                                 LIMIT ?, ?";
 203
 204                         $parameters[] = ($page - 1) * 100;
 205                         $parameters[] = 100;
 206
 207                         $contacts = DBA::p($sql, ...$parameters);
 208                         while ($contact = DBA::fetch($contacts)) {
 209                                 $list[] = $contact['url'];
 210                         }
 211                         DBA::close($contacts);
 212
 213                         if (!empty($list)) {
 214                                 $data['next'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=' . ($page + 1);
 215                         }
 216
 217                         $data['partOf'] = DI::baseUrl() . $modulePath . $owner['nickname'];
 218
 219                         $data['orderedItems'] = $list;
 220                 }
 221
 222                 return $data;
 223         }
 224
 225         /**
 226          * Public posts for the given owner
 227          *
 228          * @param array   $owner     Owner array
 229          * @param integer $page      Page number
 230          * @param string  $requester URL of requesting account
 231          *
 232          * @return array of posts
 233          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 234          * @throws \ImagickException
 235          */
 236         public static function getOutbox($owner, $page = null, $requester = '')
 237         {
 238                 $public_contact = Contact::getIdForURL($owner['url']);
 239                 $condition = ['uid' => 0, 'contact-id' => $public_contact,
 240                         'private' => [Item::PUBLIC, Item::UNLISTED]];
 241
 242                 if (!empty($requester)) {
 243                         $requester_id = Contact::getIdForURL($requester, $owner['uid']);
 244                         if (!empty($requester_id)) {
 245                                 $permissionSets = DI::permissionSet()->selectByContactId($requester_id, $owner['uid']);
 246                                 if (!empty($permissionSets)) {
 247                                         $condition = ['uid' => $owner['uid'], 'origin' => true,
 248                                                 'psid' => array_merge($permissionSets->column('id'),
 249                                                         [DI::permissionSet()->getIdFromACL($owner['uid'], '', '', '', '')])];
 250                                 }
 251                         }
 252                 }
 253
 254                 $condition = array_merge($condition,
 255                         ['author-id' => $public_contact,
 256                         'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT],
 257                         'deleted' => false, 'visible' => true]);
 258
 259                 $count = Post::count($condition);
 260
 261                 $data = ['@context' => ActivityPub::CONTEXT];
 262                 $data['id'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
 263                 $data['type'] = 'OrderedCollection';
 264                 $data['totalItems'] = $count;
 265
 266                 if (empty($page)) {
 267                         $data['first'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=1';
 268                 } else {
 269                         $data['type'] = 'OrderedCollectionPage';
 270                         $list = [];
 271
 272                         $condition['parent-network'] = Protocol::NATIVE_SUPPORT;
 273
 274                         $items = Post::select(['id'], $condition, ['limit' => [($page - 1) * 20, 20], 'order' => ['created' => true]]);
 275                         while ($item = Post::fetch($items)) {
 276                                 $activity = self::createActivityFromItem($item['id'], true);
 277                                 $activity['type'] = $activity['type'] == 'Update' ? 'Create' : $activity['type'];
 278
 279                                 // Only list "Create" activity objects here, no reshares
 280                                 if (!empty($activity['object']) && ($activity['type'] == 'Create')) {
 281                                         $list[] = $activity['object'];
 282                                 }
 283                         }
 284                         DBA::close($items);
 285
 286                         if (!empty($list)) {
 287                                 $data['next'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=' . ($page + 1);
 288                         }
 289
 290                         $data['partOf'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
 291
 292                         $data['orderedItems'] = $list;
 293                 }
 294
 295                 return $data;
 296         }
 297
 298         /**
 299          * Return the service array containing information the used software and it's url
 300          *
 301          * @return array with service data
 302          */
 303         private static function getService()
 304         {
 305                 return ['type' => 'Service',
 306                         'name' =>  FRIENDICA_PLATFORM . " '" . FRIENDICA_CODENAME . "' " . FRIENDICA_VERSION . '-' . DB_UPDATE_VERSION,
 307                         'url' => DI::baseUrl()->get()];
 308         }
 309
 310         /**
 311          * Return the ActivityPub profile of the given user
 312          *
 313          * @param integer $uid User ID
 314          * @return array with profile data
 315          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 316          */
 317         public static function getProfile($uid)
 318         {
 319                 if ($uid != 0) {
 320                         $condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
 321                                 'account_removed' => false, 'verified' => true];
 322                         $fields = ['guid', 'nickname', 'pubkey', 'account-type', 'page-flags'];
 323                         $user = DBA::selectFirst('user', $fields, $condition);
 324                         if (!DBA::isResult($user)) {
 325                                 return [];
 326                         }
 327
 328                         $fields = ['locality', 'region', 'country-name', 'net-publish'];
 329                         $profile = DBA::selectFirst('profile', $fields, ['uid' => $uid]);
 330                         if (!DBA::isResult($profile)) {
 331                                 return [];
 332                         }
 333
 334                         $fields = ['id', 'name', 'url', 'location', 'about', 'avatar', 'photo', 'updated'];
 335                         $contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
 336                         if (!DBA::isResult($contact)) {
 337                                 return [];
 338                         }
 339                 } else {
 340                         $contact = User::getSystemAccount();
 341                         $user = ['guid' => '', 'nickname' => $contact['nick'], 'pubkey' => $contact['pubkey'],
 342                                 'account-type' => $contact['contact-type'], 'page-flags' => User::PAGE_FLAGS_NORMAL];
 343                         $profile = ['locality' => '', 'region' => '', 'country-name' => '', 'net-publish' => false];
 344                 }
 345
 346                 $data = ['@context' => ActivityPub::CONTEXT];
 347                 $data['id'] = $contact['url'];
 348
 349                 if (!empty($user['guid'])) {
 350                         $data['diaspora:guid'] = $user['guid'];
 351                 }
 352
 353                 $data['type'] = ActivityPub::ACCOUNT_TYPES[$user['account-type']];
 354
 355                 if ($uid != 0) {
 356                         $data['following'] = DI::baseUrl() . '/following/' . $user['nickname'];
 357                         $data['followers'] = DI::baseUrl() . '/followers/' . $user['nickname'];
 358                         $data['inbox'] = DI::baseUrl() . '/inbox/' . $user['nickname'];
 359                         $data['outbox'] = DI::baseUrl() . '/outbox/' . $user['nickname'];
 360                 } else {
 361                         $data['inbox'] = DI::baseUrl() . '/friendica/inbox';
 362                 }
 363
 364                 $data['preferredUsername'] = $user['nickname'];
 365                 $data['name'] = $contact['name'];
 366
 367                 if (!empty($profile['country-name'] . $profile['region'] . $profile['locality'])) {
 368                         $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $profile['country-name'],
 369                                 'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
 370                 }
 371
 372                 if (!empty($contact['about'])) {
 373                         $data['summary'] = BBCode::convert($contact['about'], false);
 374                 }
 375
 376                 $data['url'] = $contact['url'];
 377                 $data['manuallyApprovesFollowers'] = in_array($user['page-flags'], [User::PAGE_FLAGS_NORMAL, User::PAGE_FLAGS_PRVGROUP]);
 378                 $data['discoverable'] = $profile['net-publish'];
 379                 $data['publicKey'] = ['id' => $contact['url'] . '#main-key',
 380                         'owner' => $contact['url'],
 381                         'publicKeyPem' => $user['pubkey']];
 382                 $data['endpoints'] = ['sharedInbox' => DI::baseUrl() . '/inbox'];
 383                 $data['icon'] = ['type' => 'Image', 'url' => Contact::getAvatarUrlForId($contact['id'], '', $contact['updated'])];
 384
 385                 $resourceid = Photo::ridFromURI($contact['photo']);
 386                 if (!empty($resourceid)) {
 387                         $photo = Photo::selectFirst(['type'], ["resource-id" => $resourceid]);
 388                         if (!empty($photo['type'])) {
 389                                 $data['icon']['mediaType'] = $photo['type'];
 390                         }
 391                 }
 392
 393                 if (!empty($contact['header'])) {
 394                         $data['image'] = ['type' => 'Image', 'url' => Contact::getHeaderUrlForId($contact['id'], '', $contact['updated'])];
 395
 396                         $resourceid = Photo::ridFromURI($contact['header']);
 397                         if (!empty($resourceid)) {
 398                                 $photo = Photo::selectFirst(['type'], ["resource-id" => $resourceid]);
 399                                 if (!empty($photo['type'])) {
 400                                         $data['image']['mediaType'] = $photo['type'];
 401                                 }
 402                         }
 403                 }
 404
 405                 $data['generator'] = self::getService();
 406
 407                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
 408                 return $data;
 409         }
 410
 411         /**
 412          * @param string $username
 413          * @return array
 414          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 415          */
 416         public static function getDeletedUser($username)
 417         {
 418                 return [
 419                         '@context' => ActivityPub::CONTEXT,
 420                         'id' => DI::baseUrl() . '/profile/' . $username,
 421                         'type' => 'Tombstone',
 422                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 423                         'updated' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 424                         'deleted' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 425                 ];
 426         }
 427
 428         /**
 429          * Returns an array with permissions of a given item array
 430          *
 431          * @param array $item
 432          *
 433          * @return array with permissions
 434          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 435          * @throws \ImagickException
 436          */
 437         private static function fetchPermissionBlockFromConversation($item)
 438         {
 439                 if (empty($item['thr-parent'])) {
 440                         return [];
 441                 }
 442
 443                 $condition = ['item-uri' => $item['thr-parent'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
 444                 $conversation = DBA::selectFirst('conversation', ['source'], $condition);
 445                 if (!DBA::isResult($conversation)) {
 446                         return [];
 447                 }
 448
 449                 $activity = json_decode($conversation['source'], true);
 450
 451                 $actor = JsonLD::fetchElement($activity, 'actor', 'id');
 452                 if (!empty($actor)) {
 453                         $permissions['to'][] = $actor;
 454                         $profile = APContact::getByURL($actor);
 455                 } else {
 456                         $profile = [];
 457                 }
 458
 459                 $item_profile = APContact::getByURL($item['author-link']);
 460                 $exclude[] = $item['author-link'];
 461
 462                 if ($item['gravity'] == GRAVITY_PARENT) {
 463                         $exclude[] = $item['owner-link'];
 464                 }
 465
 466                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 467                         if (empty($activity[$element])) {
 468                                 continue;
 469                         }
 470                         if (is_string($activity[$element])) {
 471                                 $activity[$element] = [$activity[$element]];
 472                         }
 473
 474                         foreach ($activity[$element] as $receiver) {
 475                                 if (empty($receiver)) {
 476                                         continue;
 477                                 }
 478
 479                                 if (!empty($profile['followers']) && $receiver == $profile['followers'] && !empty($item_profile['followers'])) {
 480                                         $permissions[$element][] = $item_profile['followers'];
 481                                 } elseif (!in_array($receiver, $exclude)) {
 482                                         $permissions[$element][] = $receiver;
 483                                 }
 484                         }
 485                 }
 486                 return $permissions;
 487         }
 488
 489         /**
 490          * Check if the given item id is from ActivityPub
 491          *
 492          * @param integer $item_id
 493          * @return boolean "true" if the post is from ActivityPub
 494          */
 495         private static function isAPPost(int $item_id)
 496         {
 497                 if (empty($item_id)) {
 498                         return false;
 499                 }
 500
 501                 return Post::exists(['id' => $item_id, 'network' => Protocol::ACTIVITYPUB]);
 502         }
 503
 504         /**
 505          * Creates an array of permissions from an item thread
 506          *
 507          * @param array   $item       Item array
 508          * @param boolean $blindcopy  addressing via "bcc" or "cc"?
 509          * @param integer $last_id    Last item id for adding receivers
 510          * @param boolean $forum_mode "true" means that we are sending content to a forum
 511          *
 512          * @return array with permission data
 513          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 514          * @throws \ImagickException
 515          */
 516         private static function createPermissionBlockForItem($item, $blindcopy, $last_id = 0, $forum_mode = false)
 517         {
 518                 if ($last_id == 0) {
 519                         $last_id = $item['id'];
 520                 }
 521
 522                 $always_bcc = false;
 523
 524                 // Check if we should always deliver our stuff via BCC
 525                 if (!empty($item['uid'])) {
 526                         $profile = User::getOwnerDataById($item['uid']);
 527                         if (!empty($profile)) {
 528                                 $always_bcc = $profile['hide-friends'];
 529                         }
 530                 }
 531
 532                 if (DI::config()->get('system', 'ap_always_bcc')) {
 533                         $always_bcc = true;
 534                 }
 535
 536                 if (self::isAnnounce($item) || DI::config()->get('debug', 'total_ap_delivery') || self::isAPPost($last_id)) {
 537                         // Will be activated in a later step
 538                         $networks = Protocol::FEDERATED;
 539                 } else {
 540                         // For now only send to these contacts:
 541                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 542                 }
 543
 544                 $data = ['to' => [], 'cc' => [], 'bcc' => []];
 545
 546                 if ($item['gravity'] == GRAVITY_PARENT) {
 547                         $actor_profile = APContact::getByURL($item['owner-link']);
 548                 } else {
 549                         $actor_profile = APContact::getByURL($item['author-link']);
 550                 }
 551
 552                 $exclusive = false;
 553
 554                 $terms = Tag::getByURIId($item['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
 555
 556                 if ($item['private'] != Item::PRIVATE) {
 557                         // Directly mention the original author upon a quoted reshare.
 558                         // Else just ensure that the original author receives the reshare.
 559                         $announce = self::getAnnounceArray($item);
 560                         if (!empty($announce['comment'])) {
 561                                 $data['to'][] = $announce['actor']['url'];
 562                         } elseif (!empty($announce)) {
 563                                 $data['cc'][] = $announce['actor']['url'];
 564                         }
 565
 566                         $data = array_merge($data, self::fetchPermissionBlockFromConversation($item));
 567
 568                         // Check if the item is completely public or unlisted
 569                         if ($item['private'] == Item::PUBLIC) {
 570                                 $data['to'][] = ActivityPub::PUBLIC_COLLECTION;
 571                         } else {
 572                                 $data['cc'][] = ActivityPub::PUBLIC_COLLECTION;
 573                         }
 574
 575                         foreach ($terms as $term) {
 576                                 $profile = APContact::getByURL($term['url'], false);
 577                                 if (!empty($profile)) {
 578                                         if ($term['type'] == Tag::EXCLUSIVE_MENTION) {
 579                                                 $exclusive = true;
 580                                                 if (!empty($profile['followers']) && ($profile['type'] == 'Group')) {
 581                                                         $data['cc'][] = $profile['followers'];
 582                                                 }
 583                                         }
 584                                         $data['to'][] = $profile['url'];
 585                                 }
 586                         }
 587                 } else {
 588                         $receiver_list = Item::enumeratePermissions($item, true);
 589
 590                         foreach ($terms as $term) {
 591                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 592                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 593                                         $contact = DBA::selectFirst('contact', ['url', 'network', 'protocol', 'gsid'], ['id' => $cid, 'network' => Protocol::FEDERATED]);
 594                                         if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
 595                                                 continue;
 596                                         }
 597
 598                                         if (!empty($profile = APContact::getByURL($contact['url'], false))) {
 599                                                 $data['to'][] = $profile['url'];
 600                                         }
 601                                 }
 602                         }
 603
 604                         foreach ($receiver_list as $receiver) {
 605                                 $contact = DBA::selectFirst('contact', ['url', 'hidden', 'network', 'protocol', 'gsid'], ['id' => $receiver, 'network' => Protocol::FEDERATED]);
 606                                 if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
 607                                         continue;
 608                                 }
 609
 610                                 if (!empty($profile = APContact::getByURL($contact['url'], false))) {
 611                                         if ($contact['hidden'] || $always_bcc) {
 612                                                 $data['bcc'][] = $profile['url'];
 613                                         } else {
 614                                                 $data['cc'][] = $profile['url'];
 615                                         }
 616                                 }
 617                         }
 618                 }
 619
 620                 if (!empty($item['parent'])) {
 621                         $parents = Post::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']]);
 622                         while ($parent = Post::fetch($parents)) {
 623                                 if ($parent['gravity'] == GRAVITY_PARENT) {
 624                                         $profile = APContact::getByURL($parent['owner-link'], false);
 625                                         if (!empty($profile)) {
 626                                                 if ($item['gravity'] != GRAVITY_PARENT) {
 627                                                         // Comments to forums are directed to the forum
 628                                                         // But comments to forums aren't directed to the followers collection
 629                                                         // This rule is only valid when the actor isn't the forum.
 630                                                         // The forum needs to transmit their content to their followers.
 631                                                         if (($profile['type'] == 'Group') && ($profile['url'] != ($actor_profile['url'] ?? ''))) {
 632                                                                 $data['to'][] = $profile['url'];
 633                                                         } else {
 634                                                                 $data['cc'][] = $profile['url'];
 635                                                                 if (($item['private'] != Item::PRIVATE) && !empty($actor_profile['followers'])) {
 636                                                                         $data['cc'][] = $actor_profile['followers'];
 637                                                                 }
 638                                                         }
 639                                                 } elseif (!$exclusive) {
 640                                                         // Public thread parent post always are directed to the followers.
 641                                                         // This mustn't be done by posts that are directed to forum servers via the exclusive mention.
 642                                                         // But possibly in that case we could add the "followers" collection of the forum to the message.
 643                                                         if (($item['private'] != Item::PRIVATE) && !$forum_mode) {
 644                                                                 $data['cc'][] = $actor_profile['followers'];
 645                                                         }
 646                                                 }
 647                                         }
 648                                 }
 649
 650                                 // Don't include data from future posts
 651                                 if ($parent['id'] >= $last_id) {
 652                                         continue;
 653                                 }
 654
 655                                 $profile = APContact::getByURL($parent['author-link'], false);
 656                                 if (!empty($profile)) {
 657                                         if (($profile['type'] == 'Group') || ($parent['uri'] == $item['thr-parent'])) {
 658                                                 $data['to'][] = $profile['url'];
 659                                         } else {
 660                                                 $data['cc'][] = $profile['url'];
 661                                         }
 662                                 }
 663                         }
 664                         DBA::close($parents);
 665                 }
 666
 667                 $data['to'] = array_unique($data['to']);
 668                 $data['cc'] = array_unique($data['cc']);
 669                 $data['bcc'] = array_unique($data['bcc']);
 670
 671                 if (($key = array_search($item['author-link'], $data['to'])) !== false) {
 672                         unset($data['to'][$key]);
 673                 }
 674
 675                 if (($key = array_search($item['author-link'], $data['cc'])) !== false) {
 676                         unset($data['cc'][$key]);
 677                 }
 678
 679                 if (($key = array_search($item['author-link'], $data['bcc'])) !== false) {
 680                         unset($data['bcc'][$key]);
 681                 }
 682
 683                 foreach ($data['to'] as $to) {
 684                         if (($key = array_search($to, $data['cc'])) !== false) {
 685                                 unset($data['cc'][$key]);
 686                         }
 687
 688                         if (($key = array_search($to, $data['bcc'])) !== false) {
 689                                 unset($data['bcc'][$key]);
 690                         }
 691                 }
 692
 693                 foreach ($data['cc'] as $cc) {
 694                         if (($key = array_search($cc, $data['bcc'])) !== false) {
 695                                 unset($data['bcc'][$key]);
 696                         }
 697                 }
 698
 699                 $receivers = ['to' => array_values($data['to']), 'cc' => array_values($data['cc']), 'bcc' => array_values($data['bcc'])];
 700
 701                 if (!$blindcopy) {
 702                         unset($receivers['bcc']);
 703                 }
 704
 705                 return $receivers;
 706         }
 707
 708         /**
 709          * Check if an inbox is archived
 710          *
 711          * @param string $url Inbox url
 712          *
 713          * @return boolean "true" if inbox is archived
 714          */
 715         public static function archivedInbox($url)
 716         {
 717                 return DBA::exists('inbox-status', ['url' => $url, 'archive' => true]);
 718         }
 719
 720         /**
 721          * Check if a given contact should be delivered via AP
 722          *
 723          * @param array $contact
 724          * @param array $networks
 725          * @return bool
 726          * @throws Exception
 727          */
 728         private static function isAPContact(array $contact, array $networks)
 729         {
 730                 if (in_array($contact['network'], $networks) || ($contact['protocol'] == Protocol::ACTIVITYPUB)) {
 731                         return true;
 732                 }
 733
 734                 return GServer::getProtocol($contact['gsid'] ?? 0) == Post\DeliveryData::ACTIVITYPUB;
 735         }
 736
 737         /**
 738          * Fetches a list of inboxes of followers of a given user
 739          *
 740          * @param integer $uid      User ID
 741          * @param boolean $personal fetch personal inboxes
 742          * @param boolean $all_ap   Retrieve all AP enabled inboxes
 743          *
 744          * @return array of follower inboxes
 745          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 746          * @throws \ImagickException
 747          */
 748         public static function fetchTargetInboxesforUser($uid, $personal = false, bool $all_ap = false)
 749         {
 750                 $inboxes = [];
 751
 752                 $isforum = false;
 753
 754                 if (!empty($item['uid'])) {
 755                         $profile = User::getOwnerDataById($item['uid']);
 756                         if (!empty($profile)) {
 757                                 $isforum = $profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY;
 758                         }
 759                 }
 760
 761                 if (DI::config()->get('debug', 'total_ap_delivery') || $all_ap) {
 762                         // Will be activated in a later step
 763                         $networks = Protocol::FEDERATED;
 764                 } else {
 765                         // For now only send to these contacts:
 766                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 767                 }
 768
 769                 $condition = ['uid' => $uid, 'archive' => false, 'pending' => false, 'blocked' => false, 'network' => Protocol::FEDERATED];
 770
 771                 if (!empty($uid)) {
 772                         $condition['rel'] = [Contact::FOLLOWER, Contact::FRIEND];
 773                 }
 774
 775                 $contacts = DBA::select('contact', ['id', 'url', 'network', 'protocol', 'gsid'], $condition);
 776                 while ($contact = DBA::fetch($contacts)) {
 777                         if (!self::isAPContact($contact, $networks)) {
 778                                 continue;
 779                         }
 780
 781                         if ($isforum && ($contact['network'] == Protocol::DFRN)) {
 782                                 continue;
 783                         }
 784
 785                         if (Network::isUrlBlocked($contact['url'])) {
 786                                 continue;
 787                         }
 788
 789                         $profile = APContact::getByURL($contact['url'], false);
 790                         if (!empty($profile)) {
 791                                 if (empty($profile['sharedinbox']) || $personal || Contact::isLocal($contact['url'])) {
 792                                         $target = $profile['inbox'];
 793                                 } else {
 794                                         $target = $profile['sharedinbox'];
 795                                 }
 796                                 if (!self::archivedInbox($target)) {
 797                                         $inboxes[$target][] = $contact['id'];
 798                                 }
 799                         }
 800                 }
 801                 DBA::close($contacts);
 802
 803                 return $inboxes;
 804         }
 805
 806         /**
 807          * Fetches an array of inboxes for the given item and user
 808          *
 809          * @param array   $item       Item array
 810          * @param integer $uid        User ID
 811          * @param boolean $personal   fetch personal inboxes
 812          * @param integer $last_id    Last item id for adding receivers
 813          * @param boolean $forum_mode "true" means that we are sending content to a forum
 814          * @return array with inboxes
 815          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 816          * @throws \ImagickException
 817          */
 818         public static function fetchTargetInboxes($item, $uid, $personal = false, $last_id = 0, $forum_mode = false)
 819         {
 820                 $permissions = self::createPermissionBlockForItem($item, true, $last_id, $forum_mode);
 821                 if (empty($permissions)) {
 822                         return [];
 823                 }
 824
 825                 $inboxes = [];
 826
 827                 if ($item['gravity'] == GRAVITY_ACTIVITY) {
 828                         $item_profile = APContact::getByURL($item['author-link'], false);
 829                 } else {
 830                         $item_profile = APContact::getByURL($item['owner-link'], false);
 831                 }
 832
 833                 if (empty($item_profile)) {
 834                         return [];
 835                 }
 836
 837                 $profile_uid = User::getIdForURL($item_profile['url']);
 838
 839                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 840                         if (empty($permissions[$element])) {
 841                                 continue;
 842                         }
 843
 844                         $blindcopy = in_array($element, ['bto', 'bcc']);
 845
 846                         foreach ($permissions[$element] as $receiver) {
 847                                 if (empty($receiver) || Network::isUrlBlocked($receiver)) {
 848                                         continue;
 849                                 }
 850
 851                                 if ($item_profile && ($receiver == $item_profile['followers']) && ($uid == $profile_uid)) {
 852                                         $inboxes = array_merge($inboxes, self::fetchTargetInboxesforUser($uid, $personal, self::isAPPost($last_id)));
 853                                 } else {
 854                                         $profile = APContact::getByURL($receiver, false);
 855                                         if (!empty($profile)) {
 856                                                 $contact = Contact::getByURLForUser($receiver, $uid, false, ['id']);
 857
 858                                                 if (empty($profile['sharedinbox']) || $personal || $blindcopy || Contact::isLocal($receiver)) {
 859                                                         $target = $profile['inbox'];
 860                                                 } else {
 861                                                         $target = $profile['sharedinbox'];
 862                                                 }
 863                                                 if (!self::archivedInbox($target)) {
 864                                                         $inboxes[$target][] = $contact['id'] ?? 0;
 865                                                 }
 866                                         }
 867                                 }
 868                         }
 869                 }
 870
 871                 return $inboxes;
 872         }
 873
 874         /**
 875          * Creates an array in the structure of the item table for a given mail id
 876          *
 877          * @param integer $mail_id
 878          *
 879          * @return array
 880          * @throws \Exception
 881          */
 882         public static function ItemArrayFromMail($mail_id, $use_title = false)
 883         {
 884                 $mail = DBA::selectFirst('mail', [], ['id' => $mail_id]);
 885                 if (!DBA::isResult($mail)) {
 886                         return [];
 887                 }
 888
 889                 $reply = DBA::selectFirst('mail', ['uri', 'uri-id', 'from-url'], ['parent-uri' => $mail['parent-uri'], 'reply' => false]);
 890
 891                 // Making the post more compatible for Mastodon by:
 892                 // - Making it a note and not an article (no title)
 893                 // - Moving the title into the "summary" field that is used as a "content warning"
 894
 895                 if (!$use_title) {
 896                         $mail['body']         = '[abstract]' . $mail['title'] . "[/abstract]\n" . $mail['body'];
 897                         $mail['title']        = '';
 898                 }
 899
 900                 $mail['author-link']      = $mail['owner-link'] = $mail['from-url'];
 901                 $mail['owner-id']         = $mail['author-id'];
 902                 $mail['allow_cid']        = '<'.$mail['contact-id'].'>';
 903                 $mail['allow_gid']        = '';
 904                 $mail['deny_cid']         = '';
 905                 $mail['deny_gid']         = '';
 906                 $mail['private']          = Item::PRIVATE;
 907                 $mail['deleted']          = false;
 908                 $mail['edited']           = $mail['created'];
 909                 $mail['plink']            = DI::baseUrl() . '/message/' . $mail['id'];
 910                 $mail['parent-uri']       = $reply['uri'];
 911                 $mail['parent-uri-id']    = $reply['uri-id'];
 912                 $mail['parent-author-id'] = Contact::getIdForURL($reply['from-url'], 0, false);
 913                 $mail['gravity']          = ($mail['reply'] ? GRAVITY_COMMENT: GRAVITY_PARENT);
 914                 $mail['event-type']       = '';
 915                 $mail['language']         = '';
 916                 $mail['parent']           = 0;
 917
 918                 return $mail;
 919         }
 920
 921         /**
 922          * Creates an activity array for a given mail id
 923          *
 924          * @param integer $mail_id
 925          * @param boolean $object_mode Is the activity item is used inside another object?
 926          *
 927          * @return array of activity
 928          * @throws \Exception
 929          */
 930         public static function createActivityFromMail($mail_id, $object_mode = false)
 931         {
 932                 $mail = self::ItemArrayFromMail($mail_id);
 933                 if (empty($mail)) {
 934                         return [];
 935                 }
 936                 $object = self::createNote($mail);
 937
 938                 if (!$object_mode) {
 939                         $data = ['@context' => ActivityPub::CONTEXT];
 940                 } else {
 941                         $data = [];
 942                 }
 943
 944                 $data['id'] = $mail['uri'] . '/Create';
 945                 $data['type'] = 'Create';
 946                 $data['actor'] = $mail['author-link'];
 947                 $data['published'] = DateTimeFormat::utc($mail['created'] . '+00:00', DateTimeFormat::ATOM);
 948                 $data['instrument'] = self::getService();
 949                 $data = array_merge($data, self::createPermissionBlockForItem($mail, true));
 950
 951                 if (empty($data['to']) && !empty($data['cc'])) {
 952                         $data['to'] = $data['cc'];
 953                 }
 954
 955                 if (empty($data['to']) && !empty($data['bcc'])) {
 956                         $data['to'] = $data['bcc'];
 957                 }
 958
 959                 unset($data['cc']);
 960                 unset($data['bcc']);
 961
 962                 $object['to'] = $data['to'];
 963                 $object['tag'] = [['type' => 'Mention', 'href' => $object['to'][0], 'name' => '']];
 964
 965                 unset($object['cc']);
 966                 unset($object['bcc']);
 967
 968                 $data['directMessage'] = true;
 969
 970                 $data['object'] = $object;
 971
 972                 $owner = User::getOwnerDataById($mail['uid']);
 973
 974                 if (!$object_mode && !empty($owner)) {
 975                         return LDSignature::sign($data, $owner);
 976                 } else {
 977                         return $data;
 978                 }
 979         }
 980
 981         /**
 982          * Returns the activity type of a given item
 983          *
 984          * @param array $item
 985          *
 986          * @return string with activity type
 987          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 988          * @throws \ImagickException
 989          */
 990         private static function getTypeOfItem($item)
 991         {
 992                 $reshared = false;
 993
 994                 // Only check for a reshare, if it is a real reshare and no quoted reshare
 995                 if (strpos($item['body'], "[share") === 0) {
 996                         $announce = self::getAnnounceArray($item);
 997                         $reshared = !empty($announce);
 998                 }
 999
1000                 if ($reshared) {
1001                         $type = 'Announce';
1002                 } elseif ($item['verb'] == Activity::POST) {
1003                         if ($item['created'] == $item['edited']) {
1004                                 $type = 'Create';
1005                         } else {
1006                                 $type = 'Update';
1007                         }
1008                 } elseif ($item['verb'] == Activity::LIKE) {
1009                         $type = 'Like';
1010                 } elseif ($item['verb'] == Activity::DISLIKE) {
1011                         $type = 'Dislike';
1012                 } elseif ($item['verb'] == Activity::ATTEND) {
1013                         $type = 'Accept';
1014                 } elseif ($item['verb'] == Activity::ATTENDNO) {
1015                         $type = 'Reject';
1016                 } elseif ($item['verb'] == Activity::ATTENDMAYBE) {
1017                         $type = 'TentativeAccept';
1018                 } elseif ($item['verb'] == Activity::FOLLOW) {
1019                         $type = 'Follow';
1020                 } elseif ($item['verb'] == Activity::TAG) {
1021                         $type = 'Add';
1022                 } elseif ($item['verb'] == Activity::ANNOUNCE) {
1023                         $type = 'Announce';
1024                 } else {
1025                         $type = '';
1026                 }
1027
1028                 return $type;
1029         }
1030
1031         /**
1032          * Creates the activity or fetches it from the cache
1033          *
1034          * @param integer $item_id
1035          * @param boolean $force Force new cache entry
1036          *
1037          * @return array with the activity
1038          * @throws \Exception
1039          */
1040         public static function createCachedActivityFromItem($item_id, $force = false)
1041         {
1042                 $cachekey = 'APDelivery:createActivity:' . $item_id;
1043
1044                 if (!$force) {
1045                         $data = DI::cache()->get($cachekey);
1046                         if (!is_null($data)) {
1047                                 return $data;
1048                         }
1049                 }
1050
1051                 $data = self::createActivityFromItem($item_id);
1052
1053                 DI::cache()->set($cachekey, $data, Duration::QUARTER_HOUR);
1054                 return $data;
1055         }
1056
1057         /**
1058          * Creates an activity array for a given item id
1059          *
1060          * @param integer $item_id
1061          * @param boolean $object_mode Is the activity item is used inside another object?
1062          *
1063          * @return false|array
1064          * @throws \Exception
1065          */
1066         public static function createActivityFromItem(int $item_id, bool $object_mode = false)
1067         {
1068                 Logger::info('Fetching activity', ['item' => $item_id]);
1069                 $item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['id' => $item_id, 'parent-network' => Protocol::NATIVE_SUPPORT]);
1070                 if (!DBA::isResult($item)) {
1071                         return false;
1072                 }
1073
1074                 // In case of a forum post ensure to return the original post if author and forum are on the same machine
1075                 if (($item['gravity'] == GRAVITY_PARENT) && !empty($item['forum_mode'])) {
1076                         $author = Contact::getById($item['author-id'], ['nurl']);
1077                         if (!empty($author['nurl'])) {
1078                                 $self = Contact::selectFirst(['uid'], ['nurl' => $author['nurl'], 'self' => true]);
1079                                 if (!empty($self['uid'])) {
1080                                         $forum_item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['uri-id' => $item['uri-id'], 'uid' => $self['uid']]);
1081                                         if (DBA::isResult($forum_item)) {
1082                                                 $item = $forum_item;
1083                                         }
1084                                 }
1085                         }
1086                 }
1087
1088                 if (empty($item['uri-id'])) {
1089                         Logger::warning('Item without uri-id', ['item' => $item]);
1090                         return false;
1091                 }
1092
1093                 if (!$item['deleted']) {
1094                         $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
1095                         $conversation = DBA::selectFirst('conversation', ['source'], $condition);
1096                         if (!$item['origin'] && DBA::isResult($conversation)) {
1097                                 $data = json_decode($conversation['source'], true);
1098                                 if (!empty($data['type'])) {
1099                                         if (in_array($data['type'], ['Create', 'Update'])) {
1100                                                 if ($object_mode) {
1101                                                         unset($data['@context']);
1102                                                         unset($data['signature']);
1103                                                 }
1104                                                 Logger::info('Return stored conversation', ['item' => $item_id]);
1105                                                 return $data;
1106                                         } elseif (in_array('as:' . $data['type'], Receiver::CONTENT_TYPES)) {
1107                                                 if (!empty($data['@context'])) {
1108                                                         $context = $data['@context'];
1109                                                         unset($data['@context']);
1110                                                 }
1111                                                 unset($data['actor']);
1112                                                 $object = $data;
1113                                         }
1114                                 }
1115                         }
1116                 }
1117
1118                 $type = self::getTypeOfItem($item);
1119
1120                 if (!$object_mode) {
1121                         $data = ['@context' => $context ?? ActivityPub::CONTEXT];
1122
1123                         if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
1124                                 $type = 'Undo';
1125                         } elseif ($item['deleted']) {
1126                                 $type = 'Delete';
1127                         }
1128                 } else {
1129                         $data = [];
1130                 }
1131
1132                 if ($type == 'Delete') {
1133                         $data['id'] = Item::newURI($item['uid'], $item['guid']) . '/' . $type;;
1134                 } elseif (($item['gravity'] == GRAVITY_ACTIVITY) && ($type != 'Undo')) {
1135                         $data['id'] = $item['uri'];
1136                 } else {
1137                         $data['id'] = $item['uri'] . '/' . $type;
1138                 }
1139
1140                 $data['type'] = $type;
1141
1142                 if (($type != 'Announce') || ($item['gravity'] != GRAVITY_PARENT)) {
1143                         $data['actor'] = $item['author-link'];
1144                 } else {
1145                         $data['actor'] = $item['owner-link'];
1146                 }
1147
1148                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1149
1150                 $data['instrument'] = self::getService();
1151
1152                 $data = array_merge($data, self::createPermissionBlockForItem($item, false));
1153
1154                 if (in_array($data['type'], ['Create', 'Update', 'Delete'])) {
1155                         $data['object'] = $object ?? self::createNote($item);
1156                 } elseif ($data['type'] == 'Add') {
1157                         $data = self::createAddTag($item, $data);
1158                 } elseif ($data['type'] == 'Announce') {
1159                         if ($item['verb'] == ACTIVITY::ANNOUNCE) {
1160                                 $data['object'] = $item['thr-parent'];
1161                         } else {
1162                                 $data = self::createAnnounce($item, $data);
1163                         }
1164                 } elseif ($data['type'] == 'Follow') {
1165                         $data['object'] = $item['parent-uri'];
1166                 } elseif ($data['type'] == 'Undo') {
1167                         $data['object'] = self::createActivityFromItem($item_id, true);
1168                 } else {
1169                         $data['diaspora:guid'] = $item['guid'];
1170                         if (!empty($item['signed_text'])) {
1171                                 $data['diaspora:like'] = $item['signed_text'];
1172                         }
1173                         $data['object'] = $item['thr-parent'];
1174                 }
1175
1176                 if (!empty($item['contact-uid'])) {
1177                         $uid = $item['contact-uid'];
1178                 } else {
1179                         $uid = $item['uid'];
1180                 }
1181
1182                 $owner = User::getOwnerDataById($uid);
1183
1184                 Logger::info('Fetched activity', ['item' => $item_id, 'uid' => $uid]);
1185
1186                 // We don't sign if we aren't the actor. This is important for relaying content especially for forums
1187                 if (!$object_mode && !empty($owner) && ($data['actor'] == $owner['url'])) {
1188                         return LDSignature::sign($data, $owner);
1189                 } else {
1190                         return $data;
1191                 }
1192
1193                 /// @todo Create "conversation" entry
1194         }
1195
1196         /**
1197          * Creates a location entry for a given item array
1198          *
1199          * @param array $item
1200          *
1201          * @return array with location array
1202          */
1203         private static function createLocation($item)
1204         {
1205                 $location = ['type' => 'Place'];
1206
1207                 if (!empty($item['location'])) {
1208                         $location['name'] = $item['location'];
1209                 }
1210
1211                 $coord = [];
1212
1213                 if (empty($item['coord'])) {
1214                         $coord = Map::getCoordinates($item['location']);
1215                 } else {
1216                         $coords = explode(' ', $item['coord']);
1217                         if (count($coords) == 2) {
1218                                 $coord = ['lat' => $coords[0], 'lon' => $coords[1]];
1219                         }
1220                 }
1221
1222                 if (!empty($coord['lat']) && !empty($coord['lon'])) {
1223                         $location['latitude'] = $coord['lat'];
1224                         $location['longitude'] = $coord['lon'];
1225                 }
1226
1227                 return $location;
1228         }
1229
1230         /**
1231          * Returns a tag array for a given item array
1232          *
1233          * @param array $item
1234          *
1235          * @return array of tags
1236          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1237          */
1238         private static function createTagList($item)
1239         {
1240                 $tags = [];
1241
1242                 $terms = Tag::getByURIId($item['uri-id'], [Tag::HASHTAG, Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1243                 foreach ($terms as $term) {
1244                         if ($term['type'] == Tag::HASHTAG) {
1245                                 $url = DI::baseUrl() . '/search?tag=' . urlencode($term['name']);
1246                                 $tags[] = ['type' => 'Hashtag', 'href' => $url, 'name' => '#' . $term['name']];
1247                         } else {
1248                                 $contact = Contact::getByURL($term['url'], false, ['addr']);
1249                                 if (empty($contact)) {
1250                                         continue;
1251                                 }
1252                                 if (!empty($contact['addr'])) {
1253                                         $mention = '@' . $contact['addr'];
1254                                 } else {
1255                                         $mention = '@' . $term['url'];
1256                                 }
1257
1258                                 $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
1259                         }
1260                 }
1261
1262                 $announce = self::getAnnounceArray($item);
1263                 // Mention the original author upon commented reshares
1264                 if (!empty($announce['comment'])) {
1265                         $tags[] = ['type' => 'Mention', 'href' => $announce['actor']['url'], 'name' => '@' . $announce['actor']['addr']];
1266                 }
1267
1268                 return $tags;
1269         }
1270
1271         /**
1272          * Adds attachment data to the JSON document
1273          *
1274          * @param array  $item Data of the item that is to be posted
1275          * @param string $type Object type
1276          *
1277          * @return array with attachment data
1278          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1279          */
1280         private static function createAttachmentList($item, $type)
1281         {
1282                 $attachments = [];
1283
1284                 $uriids = [$item['uri-id']];
1285                 $shared = BBCode::fetchShareAttributes($item['body']);
1286                 if (!empty($shared['guid'])) {
1287                         $shared_item = Post::selectFirst(['uri-id'], ['guid' => $shared['guid']]);
1288                         if (!empty($shared_item['uri-id'])) {
1289                                 $uriids[] = $shared_item['uri-id'];
1290                         }
1291                 }
1292
1293                 $urls = [];
1294                 foreach ($uriids as $uriid) {
1295                         foreach (Post\Media::getByURIId($uriid, [Post\Media::DOCUMENT, Post\Media::TORRENT]) as $attachment) {
1296                                 if (in_array($attachment['url'], $urls)) {
1297                                         continue;
1298                                 }
1299                                 $urls[] = $attachment['url'];
1300
1301                                 $attachments[] = ['type' => 'Document',
1302                                         'mediaType' => $attachment['mimetype'],
1303                                         'url' => $attachment['url'],
1304                                         'name' => $attachment['description']];
1305                         }
1306                 }
1307
1308                 if ($type != 'Note') {
1309                         return $attachments;
1310                 }
1311
1312                 foreach ($uriids as $uriid) {
1313                         foreach (Post\Media::getByURIId($uriid, [Post\Media::AUDIO, Post\Media::IMAGE, Post\Media::VIDEO]) as $attachment) {
1314                                 if (in_array($attachment['url'], $urls)) {
1315                                         continue;
1316                                 }
1317                                 $urls[] = $attachment['url'];
1318
1319                                 $attachments[] = ['type' => 'Document',
1320                                         'mediaType' => $attachment['mimetype'],
1321                                         'url' => $attachment['url'],
1322                                         'name' => $attachment['description']];
1323                         }
1324                         // Currently deactivated, since it creates side effects on Mastodon and Pleroma.
1325                         // It will be activated, once this cleared.
1326                         /*
1327                         foreach (Post\Media::getByURIId($uriid, [Post\Media::HTML]) as $attachment) {
1328                                 if (in_array($attachment['url'], $urls)) {
1329                                         continue;
1330                                 }
1331                                 $urls[] = $attachment['url'];
1332
1333                                 $attachments[] = ['type' => 'Page',
1334                                         'mediaType' => $attachment['mimetype'],
1335                                         'url' => $attachment['url'],
1336                                         'name' => $attachment['description']];
1337                         }*/
1338                 }
1339
1340                 return $attachments;
1341         }
1342
1343         /**
1344          * Callback function to replace a Friendica style mention in a mention that is used on AP
1345          *
1346          * @param array $match Matching values for the callback
1347          * @return string Replaced mention
1348          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1349          */
1350         private static function mentionCallback($match)
1351         {
1352                 if (empty($match[1])) {
1353                         return '';
1354                 }
1355
1356                 $data = Contact::getByURL($match[1], false, ['url', 'alias', 'nick']);
1357                 if (empty($data['nick'])) {
1358                         return $match[0];
1359                 }
1360
1361                 return '[url=' . $data['url'] . ']@' . $data['nick'] . '[/url]';
1362         }
1363
1364         /**
1365          * Callback function to replace a Friendica style mention in a mention for a summary
1366          *
1367          * @param array $match Matching values for the callback
1368          * @return string Replaced mention
1369          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1370          */
1371         private static function mentionAddrCallback($match)
1372         {
1373                 if (empty($match[1])) {
1374                         return '';
1375                 }
1376
1377                 $data = Contact::getByURL($match[1], false, ['addr']);
1378                 if (empty($data['addr'])) {
1379                         return $match[0];
1380                 }
1381
1382                 return '@' . $data['addr'];
1383         }
1384
1385         /**
1386          * Remove image elements since they are added as attachment
1387          *
1388          * @param string $body
1389          *
1390          * @return string with removed images
1391          */
1392         private static function removePictures($body)
1393         {
1394                 // Simplify image codes
1395                 $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $body);
1396                 $body = preg_replace("/\[img\=(.*?)\](.*?)\[\/img\]/ism", '[img]$1[/img]', $body);
1397
1398                 // Now remove local links
1399                 $body = preg_replace_callback(
1400                         '/\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]/Usi',
1401                         function ($match) {
1402                                 // We remove the link when it is a link to a local photo page
1403                                 if (Photo::isLocalPage($match[1])) {
1404                                         return '';
1405                                 }
1406                                 // otherwise we just return the link
1407                                 return '[url]' . $match[1] . '[/url]';
1408                         },
1409                         $body
1410                 );
1411
1412                 // Remove all pictures
1413                 $body = preg_replace("/\[img\]([^\[\]]*)\[\/img\]/Usi", '', $body);
1414
1415                 return $body;
1416         }
1417
1418         /**
1419          * Fetches the "context" value for a givem item array from the "conversation" table
1420          *
1421          * @param array $item
1422          *
1423          * @return string with context url
1424          * @throws \Exception
1425          */
1426         private static function fetchContextURLForItem($item)
1427         {
1428                 $conversation = DBA::selectFirst('conversation', ['conversation-href', 'conversation-uri'], ['item-uri' => $item['parent-uri']]);
1429                 if (DBA::isResult($conversation) && !empty($conversation['conversation-href'])) {
1430                         $context_uri = $conversation['conversation-href'];
1431                 } elseif (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
1432                         $context_uri = $conversation['conversation-uri'];
1433                 } else {
1434                         $context_uri = $item['parent-uri'] . '#context';
1435                 }
1436                 return $context_uri;
1437         }
1438
1439         /**
1440          * Returns if the post contains sensitive content ("nsfw")
1441          *
1442          * @param integer $uri_id
1443          *
1444          * @return boolean
1445          * @throws \Exception
1446          */
1447         private static function isSensitive($uri_id)
1448         {
1449                 return DBA::exists('tag-view', ['uri-id' => $uri_id, 'name' => 'nsfw']);
1450         }
1451
1452         /**
1453          * Creates event data
1454          *
1455          * @param array $item
1456          *
1457          * @return array with the event data
1458          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1459          */
1460         private static function createEvent($item)
1461         {
1462                 $event = [];
1463                 $event['name'] = $item['event-summary'];
1464                 $event['content'] = BBCode::convert($item['event-desc'], false, BBCode::ACTIVITYPUB);
1465                 $event['startTime'] = DateTimeFormat::utc($item['event-start'] . '+00:00', DateTimeFormat::ATOM);
1466
1467                 if (!$item['event-nofinish']) {
1468                         $event['endTime'] = DateTimeFormat::utc($item['event-finish'] . '+00:00', DateTimeFormat::ATOM);
1469                 }
1470
1471                 if (!empty($item['event-location'])) {
1472                         $item['location'] = $item['event-location'];
1473                         $event['location'] = self::createLocation($item);
1474                 }
1475
1476                 $event['dfrn:adjust'] = (bool)$item['event-adjust'];
1477
1478                 return $event;
1479         }
1480
1481         /**
1482          * Creates a note/article object array
1483          *
1484          * @param array $item
1485          *
1486          * @return array with the object data
1487          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1488          * @throws \ImagickException
1489          */
1490         public static function createNote($item)
1491         {
1492                 if (empty($item)) {
1493                         return [];
1494                 }
1495
1496                 if ($item['event-type'] == 'event') {
1497                         $type = 'Event';
1498                 } elseif (!empty($item['title'])) {
1499                         $type = 'Article';
1500                 } else {
1501                         $type = 'Note';
1502                 }
1503
1504                 if ($item['deleted']) {
1505                         $type = 'Tombstone';
1506                 }
1507
1508                 $data = [];
1509                 $data['id'] = $item['uri'];
1510                 $data['type'] = $type;
1511
1512                 if ($item['deleted']) {
1513                         return $data;
1514                 }
1515
1516                 $data['summary'] = BBCode::toPlaintext(BBCode::getAbstract($item['body'], Protocol::ACTIVITYPUB));
1517
1518                 if ($item['uri'] != $item['thr-parent']) {
1519                         $data['inReplyTo'] = $item['thr-parent'];
1520                 } else {
1521                         $data['inReplyTo'] = null;
1522                 }
1523
1524                 $data['diaspora:guid'] = $item['guid'];
1525                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1526
1527                 if ($item['created'] != $item['edited']) {
1528                         $data['updated'] = DateTimeFormat::utc($item['edited'] . '+00:00', DateTimeFormat::ATOM);
1529                 }
1530
1531                 $data['url'] = $item['plink'];
1532                 $data['attributedTo'] = $item['author-link'];
1533                 $data['sensitive'] = self::isSensitive($item['uri-id']);
1534                 $data['context'] = self::fetchContextURLForItem($item);
1535
1536                 if (!empty($item['title'])) {
1537                         $data['name'] = BBCode::toPlaintext($item['title'], false);
1538                 }
1539
1540                 $permission_block = self::createPermissionBlockForItem($item, false);
1541
1542                 $body = $item['body'];
1543
1544                 if ($type == 'Note') {
1545                         $body = $item['raw-body'] ?? self::removePictures($body);
1546                 }
1547
1548                 /**
1549                  * @todo Improve the automated summary
1550                  * This part is currently deactivated. The automated summary seems to be more
1551                  * confusing than helping. But possibly we will find a better way.
1552                  * So the code is left here for now as a reminder
1553                  *
1554                  * } elseif (($type == 'Article') && empty($data['summary'])) {
1555                  *              $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1556                  *              $summary = preg_replace_callback($regexp, ['self', 'mentionAddrCallback'], $body);
1557                  *              $data['summary'] = BBCode::toPlaintext(Plaintext::shorten(self::removePictures($summary), 1000));
1558                  * }
1559                  */
1560
1561                 if (empty($item['uid']) || !Feature::isEnabled($item['uid'], 'explicit_mentions')) {
1562                         $body = self::prependMentions($body, $item['uri-id'], $item['author-link']);
1563                 }
1564
1565                 if ($type == 'Event') {
1566                         $data = array_merge($data, self::createEvent($item));
1567                 } else {
1568                         $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1569                         $body = preg_replace_callback($regexp, ['self', 'mentionCallback'], $body);
1570
1571                         $data['content'] = BBCode::convert($body, false, BBCode::ACTIVITYPUB);
1572                 }
1573
1574                 // The regular "content" field does contain a minimized HTML. This is done since systems like
1575                 // Mastodon has got problems with - for example - embedded pictures.
1576                 // The contentMap does contain the unmodified HTML.
1577                 $language = self::getLanguage($item);
1578                 if (!empty($language)) {
1579                         $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1580                         $richbody = preg_replace_callback($regexp, ['self', 'mentionCallback'], $item['body']);
1581                         $richbody = BBCode::removeAttachment($richbody);
1582
1583                         $data['contentMap'][$language] = BBCode::convert($richbody, false, BBCode::EXTERNAL);
1584                 }
1585
1586                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
1587
1588                 if (!empty($item['signed_text']) && ($item['uri'] != $item['thr-parent'])) {
1589                         $data['diaspora:comment'] = $item['signed_text'];
1590                 }
1591
1592                 $data['attachment'] = self::createAttachmentList($item, $type);
1593                 $data['tag'] = self::createTagList($item);
1594
1595                 if (empty($data['location']) && (!empty($item['coord']) || !empty($item['location']))) {
1596                         $data['location'] = self::createLocation($item);
1597                 }
1598
1599                 if (!empty($item['app'])) {
1600                         $data['generator'] = ['type' => 'Application', 'name' => $item['app']];
1601                 }
1602
1603                 $data = array_merge($data, $permission_block);
1604
1605                 return $data;
1606         }
1607
1608         /**
1609          * Fetches the language from the post, the user or the system.
1610          *
1611          * @param array $item
1612          *
1613          * @return string language string
1614          */
1615         private static function getLanguage(array $item)
1616         {
1617                 // Try to fetch the language from the post itself
1618                 if (!empty($item['language'])) {
1619                         $languages = array_keys(json_decode($item['language'], true));
1620                         if (!empty($languages[0])) {
1621                                 return $languages[0];
1622                         }
1623                 }
1624
1625                 // Otherwise use the user's language
1626                 if (!empty($item['uid'])) {
1627                         $user = DBA::selectFirst('user', ['language'], ['uid' => $item['uid']]);
1628                         if (!empty($user['language'])) {
1629                                 return $user['language'];
1630                         }
1631                 }
1632
1633                 // And finally just use the system language
1634                 return DI::config()->get('system', 'language');
1635         }
1636
1637         /**
1638          * Creates an an "add tag" entry
1639          *
1640          * @param array $item
1641          * @param array $data activity data
1642          *
1643          * @return array with activity data for adding tags
1644          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1645          * @throws \ImagickException
1646          */
1647         private static function createAddTag($item, $data)
1648         {
1649                 $object = XML::parseString($item['object']);
1650                 $target = XML::parseString($item["target"]);
1651
1652                 $data['diaspora:guid'] = $item['guid'];
1653                 $data['actor'] = $item['author-link'];
1654                 $data['target'] = (string)$target->id;
1655                 $data['summary'] = BBCode::toPlaintext($item['body']);
1656                 $data['object'] = ['id' => (string)$object->id, 'type' => 'tag', 'name' => (string)$object->title, 'content' => (string)$object->content];
1657
1658                 return $data;
1659         }
1660
1661         /**
1662          * Creates an announce object entry
1663          *
1664          * @param array $item
1665          * @param array $data activity data
1666          *
1667          * @return array with activity data
1668          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1669          * @throws \ImagickException
1670          */
1671         private static function createAnnounce($item, $data)
1672         {
1673                 $orig_body = $item['body'];
1674                 $announce = self::getAnnounceArray($item);
1675                 if (empty($announce)) {
1676                         $data['type'] = 'Create';
1677                         $data['object'] = self::createNote($item);
1678                         return $data;
1679                 }
1680
1681                 if (empty($announce['comment'])) {
1682                         // Pure announce, without a quote
1683                         $data['type'] = 'Announce';
1684                         $data['object'] = $announce['object']['uri'];
1685                         return $data;
1686                 }
1687
1688                 // Quote
1689                 $data['type'] = 'Create';
1690                 $item['body'] = $announce['comment'] . "\n" . $announce['object']['plink'];
1691                 $data['object'] = self::createNote($item);
1692
1693                 /// @todo Finally descide how to implement this in AP. This is a possible way:
1694                 $data['object']['attachment'][] = self::createNote($announce['object']);
1695
1696                 $data['object']['source']['content'] = $orig_body;
1697                 return $data;
1698         }
1699
1700         /**
1701          * Return announce related data if the item is an annunce
1702          *
1703          * @param array $item
1704          *
1705          * @return array
1706          */
1707         public static function getAnnounceArray($item)
1708         {
1709                 $reshared = Item::getShareArray($item);
1710                 if (empty($reshared['guid'])) {
1711                         return [];
1712                 }
1713
1714                 $reshared_item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['guid' => $reshared['guid']]);
1715                 if (!DBA::isResult($reshared_item)) {
1716                         return [];
1717                 }
1718
1719                 if (!in_array($reshared_item['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN])) {
1720                         return [];
1721                 }
1722
1723                 $profile = APContact::getByURL($reshared_item['author-link'], false);
1724                 if (empty($profile)) {
1725                         return [];
1726                 }
1727
1728                 return ['object' => $reshared_item, 'actor' => $profile, 'comment' => $reshared['comment']];
1729         }
1730
1731         /**
1732          * Checks if the provided item array is an announce
1733          *
1734          * @param array $item
1735          *
1736          * @return boolean
1737          */
1738         public static function isAnnounce($item)
1739         {
1740                 if (!empty($item['verb']) && ($item['verb'] == Activity::ANNOUNCE)) {
1741                         return true;
1742                 }
1743
1744                 $announce = self::getAnnounceArray($item);
1745                 if (empty($announce)) {
1746                         return false;
1747                 }
1748
1749                 return empty($announce['comment']);
1750         }
1751
1752         /**
1753          * Creates an activity id for a given contact id
1754          *
1755          * @param integer $cid Contact ID of target
1756          *
1757          * @return bool|string activity id
1758          */
1759         public static function activityIDFromContact($cid)
1760         {
1761                 $contact = DBA::selectFirst('contact', ['uid', 'id', 'created'], ['id' => $cid]);
1762                 if (!DBA::isResult($contact)) {
1763                         return false;
1764                 }
1765
1766                 $hash = hash('ripemd128', $contact['uid'].'-'.$contact['id'].'-'.$contact['created']);
1767                 $uuid = substr($hash, 0, 8). '-' . substr($hash, 8, 4) . '-' . substr($hash, 12, 4) . '-' . substr($hash, 16, 4) . '-' . substr($hash, 20, 12);
1768                 return DI::baseUrl() . '/activity/' . $uuid;
1769         }
1770
1771         /**
1772          * Transmits a contact suggestion to a given inbox
1773          *
1774          * @param integer $uid           User ID
1775          * @param string  $inbox         Target inbox
1776          * @param integer $suggestion_id Suggestion ID
1777          *
1778          * @return boolean was the transmission successful?
1779          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1780          */
1781         public static function sendContactSuggestion($uid, $inbox, $suggestion_id)
1782         {
1783                 $owner = User::getOwnerDataById($uid);
1784
1785                 $suggestion = DI::fsuggest()->getById($suggestion_id);
1786
1787                 $data = ['@context' => ActivityPub::CONTEXT,
1788                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1789                         'type' => 'Announce',
1790                         'actor' => $owner['url'],
1791                         'object' => $suggestion->url,
1792                         'content' => $suggestion->note,
1793                         'instrument' => self::getService(),
1794                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1795                         'cc' => []];
1796
1797                 $signed = LDSignature::sign($data, $owner);
1798
1799                 Logger::log('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1800                 return HTTPSignature::transmit($signed, $inbox, $uid);
1801         }
1802
1803         /**
1804          * Transmits a profile relocation to a given inbox
1805          *
1806          * @param integer $uid   User ID
1807          * @param string  $inbox Target inbox
1808          *
1809          * @return boolean was the transmission successful?
1810          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1811          */
1812         public static function sendProfileRelocation($uid, $inbox)
1813         {
1814                 $owner = User::getOwnerDataById($uid);
1815
1816                 $data = ['@context' => ActivityPub::CONTEXT,
1817                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1818                         'type' => 'dfrn:relocate',
1819                         'actor' => $owner['url'],
1820                         'object' => $owner['url'],
1821                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1822                         'instrument' => self::getService(),
1823                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1824                         'cc' => []];
1825
1826                 $signed = LDSignature::sign($data, $owner);
1827
1828                 Logger::log('Deliver profile relocation for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1829                 return HTTPSignature::transmit($signed, $inbox, $uid);
1830         }
1831
1832         /**
1833          * Transmits a profile deletion to a given inbox
1834          *
1835          * @param integer $uid   User ID
1836          * @param string  $inbox Target inbox
1837          *
1838          * @return boolean was the transmission successful?
1839          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1840          */
1841         public static function sendProfileDeletion($uid, $inbox)
1842         {
1843                 $owner = User::getOwnerDataById($uid);
1844
1845                 if (empty($owner)) {
1846                         Logger::error('No owner data found, the deletion message cannot be processed.', ['user' => $uid]);
1847                         return false;
1848                 }
1849
1850                 if (empty($owner['uprvkey'])) {
1851                         Logger::error('No private key for owner found, the deletion message cannot be processed.', ['user' => $uid]);
1852                         return false;
1853                 }
1854
1855                 $data = ['@context' => ActivityPub::CONTEXT,
1856                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1857                         'type' => 'Delete',
1858                         'actor' => $owner['url'],
1859                         'object' => $owner['url'],
1860                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1861                         'instrument' => self::getService(),
1862                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1863                         'cc' => []];
1864
1865                 $signed = LDSignature::sign($data, $owner);
1866
1867                 Logger::log('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1868                 return HTTPSignature::transmit($signed, $inbox, $uid);
1869         }
1870
1871         /**
1872          * Transmits a profile change to a given inbox
1873          *
1874          * @param integer $uid   User ID
1875          * @param string  $inbox Target inbox
1876          *
1877          * @return boolean was the transmission successful?
1878          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1879          * @throws \ImagickException
1880          */
1881         public static function sendProfileUpdate($uid, $inbox)
1882         {
1883                 $owner = User::getOwnerDataById($uid);
1884                 $profile = APContact::getByURL($owner['url']);
1885
1886                 $data = ['@context' => ActivityPub::CONTEXT,
1887                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1888                         'type' => 'Update',
1889                         'actor' => $owner['url'],
1890                         'object' => self::getProfile($uid),
1891                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1892                         'instrument' => self::getService(),
1893                         'to' => [$profile['followers']],
1894                         'cc' => []];
1895
1896                 $signed = LDSignature::sign($data, $owner);
1897
1898                 Logger::log('Deliver profile update for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1899                 return HTTPSignature::transmit($signed, $inbox, $uid);
1900         }
1901
1902         /**
1903          * Transmits a given activity to a target
1904          *
1905          * @param string  $activity Type name
1906          * @param string  $target   Target profile
1907          * @param integer $uid      User ID
1908          * @return bool
1909          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1910          * @throws \ImagickException
1911          * @throws \Exception
1912          */
1913         public static function sendActivity($activity, $target, $uid, $id = '')
1914         {
1915                 $profile = APContact::getByURL($target);
1916                 if (empty($profile['inbox'])) {
1917                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1918                         return;
1919                 }
1920
1921                 $owner = User::getOwnerDataById($uid);
1922
1923                 if (empty($id)) {
1924                         $id = DI::baseUrl() . '/activity/' . System::createGUID();
1925                 }
1926
1927                 $data = ['@context' => ActivityPub::CONTEXT,
1928                         'id' => $id,
1929                         'type' => $activity,
1930                         'actor' => $owner['url'],
1931                         'object' => $profile['url'],
1932                         'instrument' => self::getService(),
1933                         'to' => [$profile['url']]];
1934
1935                 Logger::log('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid, Logger::DEBUG);
1936
1937                 $signed = LDSignature::sign($data, $owner);
1938                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1939         }
1940
1941         /**
1942          * Transmits a "follow object" activity to a target
1943          * This is a preparation for sending automated "follow" requests when receiving "Announce" messages
1944          *
1945          * @param string  $object Object URL
1946          * @param string  $target Target profile
1947          * @param integer $uid    User ID
1948          * @return bool
1949          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1950          * @throws \ImagickException
1951          * @throws \Exception
1952          */
1953         public static function sendFollowObject($object, $target, $uid = 0)
1954         {
1955                 $profile = APContact::getByURL($target);
1956                 if (empty($profile['inbox'])) {
1957                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1958                         return;
1959                 }
1960
1961                 if (empty($uid)) {
1962                         // Fetch the list of administrators
1963                         $admin_mail = explode(',', str_replace(' ', '', DI::config()->get('config', 'admin_email')));
1964
1965                         // We need to use some user as a sender. It doesn't care who it will send. We will use an administrator account.
1966                         $condition = ['verified' => true, 'blocked' => false, 'account_removed' => false, 'account_expired' => false, 'email' => $admin_mail];
1967                         $first_user = DBA::selectFirst('user', ['uid'], $condition);
1968                         $uid = $first_user['uid'];
1969                 }
1970
1971                 $condition = ['verb' => Activity::FOLLOW, 'uid' => 0, 'parent-uri' => $object,
1972                         'author-id' => Contact::getPublicIdByUserId($uid)];
1973                 if (Post::exists($condition)) {
1974                         Logger::log('Follow for ' . $object . ' for user ' . $uid . ' does already exist.', Logger::DEBUG);
1975                         return false;
1976                 }
1977
1978                 $owner = User::getOwnerDataById($uid);
1979
1980                 $data = ['@context' => ActivityPub::CONTEXT,
1981                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1982                         'type' => 'Follow',
1983                         'actor' => $owner['url'],
1984                         'object' => $object,
1985                         'instrument' => self::getService(),
1986                         'to' => [$profile['url']]];
1987
1988                 Logger::log('Sending follow ' . $object . ' to ' . $target . ' for user ' . $uid, Logger::DEBUG);
1989
1990                 $signed = LDSignature::sign($data, $owner);
1991                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1992         }
1993
1994         /**
1995          * Transmit a message that the contact request had been accepted
1996          *
1997          * @param string  $target Target profile
1998          * @param         $id
1999          * @param integer $uid    User ID
2000          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2001          * @throws \ImagickException
2002          */
2003         public static function sendContactAccept($target, $id, $uid)
2004         {
2005                 $profile = APContact::getByURL($target);
2006                 if (empty($profile['inbox'])) {
2007                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2008                         return;
2009                 }
2010
2011                 $owner = User::getOwnerDataById($uid);
2012                 $data = ['@context' => ActivityPub::CONTEXT,
2013                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2014                         'type' => 'Accept',
2015                         'actor' => $owner['url'],
2016                         'object' => [
2017                                 'id' => (string)$id,
2018                                 'type' => 'Follow',
2019                                 'actor' => $profile['url'],
2020                                 'object' => $owner['url']
2021                         ],
2022                         'instrument' => self::getService(),
2023                         'to' => [$profile['url']]];
2024
2025                 Logger::debug('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2026
2027                 $signed = LDSignature::sign($data, $owner);
2028                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2029         }
2030
2031         /**
2032          * Reject a contact request or terminates the contact relation
2033          *
2034          * @param string  $target Target profile
2035          * @param         $id
2036          * @param integer $uid    User ID
2037          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2038          * @throws \ImagickException
2039          */
2040         public static function sendContactReject($target, $id, $uid)
2041         {
2042                 $profile = APContact::getByURL($target);
2043                 if (empty($profile['inbox'])) {
2044                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2045                         return;
2046                 }
2047
2048                 $owner = User::getOwnerDataById($uid);
2049                 $data = ['@context' => ActivityPub::CONTEXT,
2050                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2051                         'type' => 'Reject',
2052                         'actor' => $owner['url'],
2053                         'object' => [
2054                                 'id' => (string)$id,
2055                                 'type' => 'Follow',
2056                                 'actor' => $profile['url'],
2057                                 'object' => $owner['url']
2058                         ],
2059                         'instrument' => self::getService(),
2060                         'to' => [$profile['url']]];
2061
2062                 Logger::debug('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2063
2064                 $signed = LDSignature::sign($data, $owner);
2065                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2066         }
2067
2068         /**
2069          * Transmits a message that we don't want to follow this contact anymore
2070          *
2071          * @param string  $target Target profile
2072          * @param integer $uid    User ID
2073          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2074          * @throws \ImagickException
2075          * @throws \Exception
2076          * @return bool success
2077          */
2078         public static function sendContactUndo($target, $cid, $uid)
2079         {
2080                 $profile = APContact::getByURL($target);
2081                 if (empty($profile['inbox'])) {
2082                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2083                         return false;
2084                 }
2085
2086                 $object_id = self::activityIDFromContact($cid);
2087                 if (empty($object_id)) {
2088                         return false;
2089                 }
2090
2091                 $id = DI::baseUrl() . '/activity/' . System::createGUID();
2092
2093                 $owner = User::getOwnerDataById($uid);
2094                 $data = ['@context' => ActivityPub::CONTEXT,
2095                         'id' => $id,
2096                         'type' => 'Undo',
2097                         'actor' => $owner['url'],
2098                         'object' => ['id' => $object_id, 'type' => 'Follow',
2099                                 'actor' => $owner['url'],
2100                                 'object' => $profile['url']],
2101                         'instrument' => self::getService(),
2102                         'to' => [$profile['url']]];
2103
2104                 Logger::log('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id, Logger::DEBUG);
2105
2106                 $signed = LDSignature::sign($data, $owner);
2107                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2108         }
2109
2110         private static function prependMentions($body, int $uriid, string $authorLink)
2111         {
2112                 $mentions = [];
2113
2114                 foreach (Tag::getByURIId($uriid, [Tag::IMPLICIT_MENTION]) as $tag) {
2115                         $profile = Contact::getByURL($tag['url'], false, ['addr', 'contact-type', 'nick']);
2116                         if (!empty($profile['addr'])
2117                                 && $profile['contact-type'] != Contact::TYPE_COMMUNITY
2118                                 && !strstr($body, $profile['addr'])
2119                                 && !strstr($body, $tag['url'])
2120                                 && $tag['url'] !== $authorLink
2121                         ) {
2122                                 $mentions[] = '@[url=' . $tag['url'] . ']' . $profile['nick'] . '[/url]';
2123                         }
2124                 }
2125
2126                 $mentions[] = $body;
2127
2128                 return implode(' ', $mentions);
2129         }
2130 }