src/Protocol/ActivityPub/Transmitter.php

   1 <?php
   2 /**
   3  * @file src/Protocol/ActivityPub/Transmitter.php
   4  */
   5 namespace Friendica\Protocol\ActivityPub;
   6
   7 use Friendica\BaseObject;
   8 use Friendica\Content\Feature;
   9 use Friendica\Database\DBA;
  10 use Friendica\Core\Config;
  11 use Friendica\Core\Logger;
  12 use Friendica\Core\System;
  13 use Friendica\Util\HTTPSignature;
  14 use Friendica\Core\Protocol;
  15 use Friendica\Model\Conversation;
  16 use Friendica\Model\Contact;
  17 use Friendica\Model\APContact;
  18 use Friendica\Model\Item;
  19 use Friendica\Model\Term;
  20 use Friendica\Model\User;
  21 use Friendica\Util\DateTimeFormat;
  22 use Friendica\Content\Text\BBCode;
  23 use Friendica\Util\JsonLD;
  24 use Friendica\Util\LDSignature;
  25 use Friendica\Model\Profile;
  26 use Friendica\Object\Image;
  27 use Friendica\Protocol\ActivityPub;
  28 use Friendica\Core\Cache;
  29 use Friendica\Util\Map;
  30 use Friendica\Util\Network;
  31
  32 require_once 'include/api.php';
  33 require_once 'mod/share.php';
  34
  35 /**
  36  * @brief ActivityPub Transmitter Protocol class
  37  *
  38  * To-Do:
  39  * - Undo Announce
  40  */
  41 class Transmitter
  42 {
  43         /**
  44          * collects the lost of followers of the given owner
  45          *
  46          * @param array   $owner Owner array
  47          * @param integer $page  Page number
  48          *
  49          * @return array of owners
  50          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  51          */
  52         public static function getFollowers($owner, $page = null)
  53         {
  54                 $condition = ['rel' => [Contact::FOLLOWER, Contact::FRIEND], 'network' => Protocol::NATIVE_SUPPORT, 'uid' => $owner['uid'],
  55                         'self' => false, 'deleted' => false, 'hidden' => false, 'archive' => false, 'pending' => false];
  56                 $count = DBA::count('contact', $condition);
  57
  58                 $data = ['@context' => ActivityPub::CONTEXT];
  59                 $data['id'] = System::baseUrl() . '/followers/' . $owner['nickname'];
  60                 $data['type'] = 'OrderedCollection';
  61                 $data['totalItems'] = $count;
  62
  63                 // When we hide our friends we will only show the pure number but don't allow more.
  64                 $profile = Profile::getByUID($owner['uid']);
  65                 if (!empty($profile['hide-friends'])) {
  66                         return $data;
  67                 }
  68
  69                 if (empty($page)) {
  70                         $data['first'] = System::baseUrl() . '/followers/' . $owner['nickname'] . '?page=1';
  71                 } else {
  72                         $list = [];
  73
  74                         $contacts = DBA::select('contact', ['url'], $condition, ['limit' => [($page - 1) * 100, 100]]);
  75                         while ($contact = DBA::fetch($contacts)) {
  76                                 $list[] = $contact['url'];
  77                         }
  78
  79                         if (!empty($list)) {
  80                                 $data['next'] = System::baseUrl() . '/followers/' . $owner['nickname'] . '?page=' . ($page + 1);
  81                         }
  82
  83                         $data['partOf'] = System::baseUrl() . '/followers/' . $owner['nickname'];
  84
  85                         $data['orderedItems'] = $list;
  86                 }
  87
  88                 return $data;
  89         }
  90
  91         /**
  92          * Create list of following contacts
  93          *
  94          * @param array   $owner Owner array
  95          * @param integer $page  Page numbe
  96          *
  97          * @return array of following contacts
  98          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  99          */
 100         public static function getFollowing($owner, $page = null)
 101         {
 102                 $condition = ['rel' => [Contact::SHARING, Contact::FRIEND], 'network' => Protocol::NATIVE_SUPPORT, 'uid' => $owner['uid'],
 103                         'self' => false, 'deleted' => false, 'hidden' => false, 'archive' => false, 'pending' => false];
 104                 $count = DBA::count('contact', $condition);
 105
 106                 $data = ['@context' => ActivityPub::CONTEXT];
 107                 $data['id'] = System::baseUrl() . '/following/' . $owner['nickname'];
 108                 $data['type'] = 'OrderedCollection';
 109                 $data['totalItems'] = $count;
 110
 111                 // When we hide our friends we will only show the pure number but don't allow more.
 112                 $profile = Profile::getByUID($owner['uid']);
 113                 if (!empty($profile['hide-friends'])) {
 114                         return $data;
 115                 }
 116
 117                 if (empty($page)) {
 118                         $data['first'] = System::baseUrl() . '/following/' . $owner['nickname'] . '?page=1';
 119                 } else {
 120                         $list = [];
 121
 122                         $contacts = DBA::select('contact', ['url'], $condition, ['limit' => [($page - 1) * 100, 100]]);
 123                         while ($contact = DBA::fetch($contacts)) {
 124                                 $list[] = $contact['url'];
 125                         }
 126
 127                         if (!empty($list)) {
 128                                 $data['next'] = System::baseUrl() . '/following/' . $owner['nickname'] . '?page=' . ($page + 1);
 129                         }
 130
 131                         $data['partOf'] = System::baseUrl() . '/following/' . $owner['nickname'];
 132
 133                         $data['orderedItems'] = $list;
 134                 }
 135
 136                 return $data;
 137         }
 138
 139         /**
 140          * Public posts for the given owner
 141          *
 142          * @param array   $owner Owner array
 143          * @param integer $page  Page numbe
 144          *
 145          * @return array of posts
 146          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 147          * @throws \ImagickException
 148          */
 149         public static function getOutbox($owner, $page = null)
 150         {
 151                 $public_contact = Contact::getIdForURL($owner['url'], 0, true);
 152
 153                 $condition = ['uid' => 0, 'contact-id' => $public_contact, 'author-id' => $public_contact,
 154                         'private' => false, 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT],
 155                         'deleted' => false, 'visible' => true, 'moderated' => false];
 156                 $count = DBA::count('item', $condition);
 157
 158                 $data = ['@context' => ActivityPub::CONTEXT];
 159                 $data['id'] = System::baseUrl() . '/outbox/' . $owner['nickname'];
 160                 $data['type'] = 'OrderedCollection';
 161                 $data['totalItems'] = $count;
 162
 163                 if (empty($page)) {
 164                         $data['first'] = System::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=1';
 165                 } else {
 166                         $list = [];
 167
 168                         $condition['parent-network'] = Protocol::NATIVE_SUPPORT;
 169
 170                         $items = Item::select(['id'], $condition, ['limit' => [($page - 1) * 20, 20], 'order' => ['created' => true]]);
 171                         while ($item = Item::fetch($items)) {
 172                                 $object = self::createObjectFromItemID($item['id']);
 173                                 unset($object['@context']);
 174                                 $list[] = $object;
 175                         }
 176
 177                         if (!empty($list)) {
 178                                 $data['next'] = System::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=' . ($page + 1);
 179                         }
 180
 181                         $data['partOf'] = System::baseUrl() . '/outbox/' . $owner['nickname'];
 182
 183                         $data['orderedItems'] = $list;
 184                 }
 185
 186                 return $data;
 187         }
 188
 189         /**
 190          * Return the ActivityPub profile of the given user
 191          *
 192          * @param integer $uid User ID
 193          * @return array with profile data
 194          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 195          */
 196         public static function getProfile($uid)
 197         {
 198                 $condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
 199                         'account_removed' => false, 'verified' => true];
 200                 $fields = ['guid', 'nickname', 'pubkey', 'account-type', 'page-flags'];
 201                 $user = DBA::selectFirst('user', $fields, $condition);
 202                 if (!DBA::isResult($user)) {
 203                         return [];
 204                 }
 205
 206                 $fields = ['locality', 'region', 'country-name'];
 207                 $profile = DBA::selectFirst('profile', $fields, ['uid' => $uid, 'is-default' => true]);
 208                 if (!DBA::isResult($profile)) {
 209                         return [];
 210                 }
 211
 212                 $fields = ['name', 'url', 'location', 'about', 'avatar', 'photo'];
 213                 $contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
 214                 if (!DBA::isResult($contact)) {
 215                         return [];
 216                 }
 217
 218                 // On old installations and never changed contacts this might not be filled
 219                 if (empty($contact['avatar'])) {
 220                         $contact['avatar'] = $contact['photo'];
 221                 }
 222
 223                 $data = ['@context' => ActivityPub::CONTEXT];
 224                 $data['id'] = $contact['url'];
 225                 $data['diaspora:guid'] = $user['guid'];
 226                 $data['type'] = ActivityPub::ACCOUNT_TYPES[$user['account-type']];
 227                 $data['following'] = System::baseUrl() . '/following/' . $user['nickname'];
 228                 $data['followers'] = System::baseUrl() . '/followers/' . $user['nickname'];
 229                 $data['inbox'] = System::baseUrl() . '/inbox/' . $user['nickname'];
 230                 $data['outbox'] = System::baseUrl() . '/outbox/' . $user['nickname'];
 231                 $data['preferredUsername'] = $user['nickname'];
 232                 $data['name'] = $contact['name'];
 233                 $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $profile['country-name'],
 234                         'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
 235                 $data['summary'] = $contact['about'];
 236                 $data['url'] = $contact['url'];
 237                 $data['manuallyApprovesFollowers'] = in_array($user['page-flags'], [User::PAGE_FLAGS_NORMAL, User::PAGE_FLAGS_PRVGROUP]);
 238                 $data['publicKey'] = ['id' => $contact['url'] . '#main-key',
 239                         'owner' => $contact['url'],
 240                         'publicKeyPem' => $user['pubkey']];
 241                 $data['endpoints'] = ['sharedInbox' => System::baseUrl() . '/inbox'];
 242                 $data['icon'] = ['type' => 'Image',
 243                         'url' => $contact['avatar']];
 244
 245                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
 246                 return $data;
 247         }
 248
 249         /**
 250          * Returns an array with permissions of a given item array
 251          *
 252          * @param array $item
 253          *
 254          * @return array with permissions
 255          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 256          * @throws \ImagickException
 257          */
 258         private static function fetchPermissionBlockFromConversation($item)
 259         {
 260                 if (empty($item['thr-parent'])) {
 261                         return [];
 262                 }
 263
 264                 $condition = ['item-uri' => $item['thr-parent'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
 265                 $conversation = DBA::selectFirst('conversation', ['source'], $condition);
 266                 if (!DBA::isResult($conversation)) {
 267                         return [];
 268                 }
 269
 270                 $activity = json_decode($conversation['source'], true);
 271
 272                 $actor = JsonLD::fetchElement($activity, 'actor', 'id');
 273                 $profile = APContact::getByURL($actor);
 274
 275                 $item_profile = APContact::getByURL($item['author-link']);
 276                 $exclude[] = $item['author-link'];
 277
 278                 if ($item['gravity'] == GRAVITY_PARENT) {
 279                         $exclude[] = $item['owner-link'];
 280                 }
 281
 282                 $permissions['to'][] = $actor;
 283
 284                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 285                         if (empty($activity[$element])) {
 286                                 continue;
 287                         }
 288                         if (is_string($activity[$element])) {
 289                                 $activity[$element] = [$activity[$element]];
 290                         }
 291
 292                         foreach ($activity[$element] as $receiver) {
 293                                 if ($receiver == $profile['followers'] && !empty($item_profile['followers'])) {
 294                                         $permissions[$element][] = $item_profile['followers'];
 295                                 } elseif (!in_array($receiver, $exclude)) {
 296                                         $permissions[$element][] = $receiver;
 297                                 }
 298                         }
 299                 }
 300                 return $permissions;
 301         }
 302
 303         /**
 304          * Creates an array of permissions from an item thread
 305          *
 306          * @param array   $item       Item array
 307          * @param boolean $blindcopy  addressing via "bcc" or "cc"?
 308          * @param integer $last_id    Last item id for adding receivers
 309          * @param boolean $forum_mode "true" means that we are sending content to a forum
 310          *
 311          * @return array with permission data
 312          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 313          * @throws \ImagickException
 314          */
 315         private static function createPermissionBlockForItem($item, $blindcopy, $last_id = 0, $forum_mode = false)
 316         {
 317                 if ($last_id == 0) {
 318                         $last_id = $item['id'];
 319                 }
 320
 321                 $always_bcc = false;
 322
 323                 // Check if we should always deliver our stuff via BCC
 324                 if (!empty($item['uid'])) {
 325                         $profile = Profile::getByUID($item['uid']);
 326                         if (!empty($profile)) {
 327                                 $always_bcc = $profile['hide-friends'];
 328                         }
 329                 }
 330
 331                 if (Config::get('debug', 'total_ap_delivery')) {
 332                         // Will be activated in a later step
 333                         $networks = [Protocol::ACTIVITYPUB, Protocol::DFRN, Protocol::DIASPORA, Protocol::OSTATUS];
 334                 } else {
 335                         // For now only send to these contacts:
 336                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 337                 }
 338
 339                 $data = ['to' => [], 'cc' => [], 'bcc' => []];
 340
 341                 if ($item['gravity'] == GRAVITY_PARENT) {
 342                         $actor_profile = APContact::getByURL($item['owner-link']);
 343                 } else {
 344                         $actor_profile = APContact::getByURL($item['author-link']);
 345                 }
 346
 347                 $terms = Term::tagArrayFromItemId($item['id'], [Term::MENTION, Term::IMPLICIT_MENTION]);
 348
 349                 if (!$item['private']) {
 350                         $data = array_merge($data, self::fetchPermissionBlockFromConversation($item));
 351
 352                         $data['to'][] = ActivityPub::PUBLIC_COLLECTION;
 353
 354                         foreach ($terms as $term) {
 355                                 $profile = APContact::getByURL($term['url'], false);
 356                                 if (!empty($profile)) {
 357                                         $data['to'][] = $profile['url'];
 358                                 }
 359                         }
 360                 } else {
 361                         $receiver_list = Item::enumeratePermissions($item);
 362
 363                         foreach ($terms as $term) {
 364                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 365                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 366                                         $contact = DBA::selectFirst('contact', ['url'], ['id' => $cid, 'network' => $networks]);
 367                                         if (DBA::isResult($contact) && !empty($profile = APContact::getByURL($contact['url'], false))) {
 368                                                 $data['to'][] = $profile['url'];
 369                                         }
 370                                 }
 371                         }
 372
 373                         foreach ($receiver_list as $receiver) {
 374                                 $contact = DBA::selectFirst('contact', ['url', 'hidden'], ['id' => $receiver, 'network' => $networks]);
 375                                 if (DBA::isResult($contact) && !empty($profile = APContact::getByURL($contact['url'], false))) {
 376                                         if ($contact['hidden'] || $always_bcc) {
 377                                                 $data['bcc'][] = $profile['url'];
 378                                         } else {
 379                                                 $data['cc'][] = $profile['url'];
 380                                         }
 381                                 }
 382                         }
 383                 }
 384
 385                 $parents = Item::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']]);
 386                 while ($parent = Item::fetch($parents)) {
 387                         if ($parent['gravity'] == GRAVITY_PARENT) {
 388                                 $profile = APContact::getByURL($parent['owner-link'], false);
 389                                 if (!empty($profile)) {
 390                                         if ($item['gravity'] != GRAVITY_PARENT) {
 391                                                 // Comments to forums are directed to the forum
 392                                                 // But comments to forums aren't directed to the followers collection
 393                                                 if ($profile['type'] == 'Group') {
 394                                                         $data['to'][] = $profile['url'];
 395                                                 } else {
 396                                                         $data['cc'][] = $profile['url'];
 397                                                         if (!$item['private']) {
 398                                                                 $data['cc'][] = $actor_profile['followers'];
 399                                                         }
 400                                                 }
 401                                         } else {
 402                                                 // Public thread parent post always are directed to the followes
 403                                                 if (!$item['private'] && !$forum_mode) {
 404                                                         $data['cc'][] = $actor_profile['followers'];
 405                                                 }
 406                                         }
 407                                 }
 408                         }
 409
 410                         // Don't include data from future posts
 411                         if ($parent['id'] >= $last_id) {
 412                                 continue;
 413                         }
 414
 415                         $profile = APContact::getByURL($parent['author-link'], false);
 416                         if (!empty($profile)) {
 417                                 if (($profile['type'] == 'Group') || ($parent['uri'] == $item['thr-parent'])) {
 418                                         $data['to'][] = $profile['url'];
 419                                 } else {
 420                                         $data['cc'][] = $profile['url'];
 421                                 }
 422                         }
 423                 }
 424                 DBA::close($parents);
 425
 426                 $data['to'] = array_unique($data['to']);
 427                 $data['cc'] = array_unique($data['cc']);
 428                 $data['bcc'] = array_unique($data['bcc']);
 429
 430                 if (($key = array_search($item['author-link'], $data['to'])) !== false) {
 431                         unset($data['to'][$key]);
 432                 }
 433
 434                 if (($key = array_search($item['author-link'], $data['cc'])) !== false) {
 435                         unset($data['cc'][$key]);
 436                 }
 437
 438                 if (($key = array_search($item['author-link'], $data['bcc'])) !== false) {
 439                         unset($data['bcc'][$key]);
 440                 }
 441
 442                 foreach ($data['to'] as $to) {
 443                         if (($key = array_search($to, $data['cc'])) !== false) {
 444                                 unset($data['cc'][$key]);
 445                         }
 446
 447                         if (($key = array_search($to, $data['bcc'])) !== false) {
 448                                 unset($data['bcc'][$key]);
 449                         }
 450                 }
 451
 452                 foreach ($data['cc'] as $cc) {
 453                         if (($key = array_search($cc, $data['bcc'])) !== false) {
 454                                 unset($data['bcc'][$key]);
 455                         }
 456                 }
 457
 458                 $receivers = ['to' => array_values($data['to']), 'cc' => array_values($data['cc']), 'bcc' => array_values($data['bcc'])];
 459
 460                 if (!$blindcopy) {
 461                         unset($receivers['bcc']);
 462                 }
 463
 464                 return $receivers;
 465         }
 466
 467         /**
 468          * Fetches a list of inboxes of followers of a given user
 469          *
 470          * @param integer $uid      User ID
 471          * @param boolean $personal fetch personal inboxes
 472          *
 473          * @return array of follower inboxes
 474          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 475          * @throws \ImagickException
 476          */
 477         public static function fetchTargetInboxesforUser($uid, $personal = false)
 478         {
 479                 $inboxes = [];
 480
 481                 if (Config::get('debug', 'total_ap_delivery')) {
 482                         // Will be activated in a later step
 483                         $networks = [Protocol::ACTIVITYPUB, Protocol::DFRN, Protocol::DIASPORA, Protocol::OSTATUS];
 484                 } else {
 485                         // For now only send to these contacts:
 486                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 487                 }
 488
 489                 $condition = ['uid' => $uid, 'network' => $networks, 'archive' => false, 'pending' => false];
 490
 491                 if (!empty($uid)) {
 492                         $condition['rel'] = [Contact::FOLLOWER, Contact::FRIEND];
 493                 }
 494
 495                 $contacts = DBA::select('contact', ['url'], $condition);
 496                 while ($contact = DBA::fetch($contacts)) {
 497                         if (Network::isUrlBlocked($contact['url'])) {
 498                                 continue;
 499                         }
 500
 501                         $profile = APContact::getByURL($contact['url'], false);
 502                         if (!empty($profile)) {
 503                                 if (empty($profile['sharedinbox']) || $personal) {
 504                                         $target = $profile['inbox'];
 505                                 } else {
 506                                         $target = $profile['sharedinbox'];
 507                                 }
 508                                 $inboxes[$target] = $target;
 509                         }
 510                 }
 511                 DBA::close($contacts);
 512
 513                 return $inboxes;
 514         }
 515
 516         /**
 517          * Fetches an array of inboxes for the given item and user
 518          *
 519          * @param array   $item       Item array
 520          * @param integer $uid        User ID
 521          * @param boolean $personal   fetch personal inboxes
 522          * @param integer $last_id    Last item id for adding receivers
 523          * @param boolean $forum_mode "true" means that we are sending content to a forum
 524          * @return array with inboxes
 525          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 526          * @throws \ImagickException
 527          */
 528         public static function fetchTargetInboxes($item, $uid, $personal = false, $last_id = 0, $forum_mode = false)
 529         {
 530                 $permissions = self::createPermissionBlockForItem($item, true, $last_id, $forum_mode);
 531                 if (empty($permissions)) {
 532                         return [];
 533                 }
 534
 535                 $inboxes = [];
 536
 537                 if ($item['gravity'] == GRAVITY_ACTIVITY) {
 538                         $item_profile = APContact::getByURL($item['author-link'], false);
 539                 } else {
 540                         $item_profile = APContact::getByURL($item['owner-link'], false);
 541                 }
 542
 543                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 544                         if (empty($permissions[$element])) {
 545                                 continue;
 546                         }
 547
 548                         $blindcopy = in_array($element, ['bto', 'bcc']);
 549
 550                         foreach ($permissions[$element] as $receiver) {
 551                                 if (Network::isUrlBlocked($receiver)) {
 552                                         continue;
 553                                 }
 554
 555                                 if ($receiver == $item_profile['followers']) {
 556                                         $inboxes = array_merge($inboxes, self::fetchTargetInboxesforUser($uid, $personal));
 557                                 } else {
 558                                         $profile = APContact::getByURL($receiver, false);
 559                                         if (!empty($profile)) {
 560                                                 if (empty($profile['sharedinbox']) || $personal || $blindcopy) {
 561                                                         $target = $profile['inbox'];
 562                                                 } else {
 563                                                         $target = $profile['sharedinbox'];
 564                                                 }
 565                                                 $inboxes[$target] = $target;
 566                                         }
 567                                 }
 568                         }
 569                 }
 570
 571                 return $inboxes;
 572         }
 573
 574         /**
 575          * Returns the activity type of a given item
 576          *
 577          * @param array $item
 578          *
 579          * @return string with activity type
 580          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 581          * @throws \ImagickException
 582          */
 583         private static function getTypeOfItem($item)
 584         {
 585                 $reshared = false;
 586
 587                 // Only check for a reshare, if it is a real reshare and no quoted reshare
 588                 if (strpos($item['body'], "[share") === 0) {
 589                         $announce = api_share_as_retweet($item);
 590                         $reshared = !empty($announce['plink']);
 591                 }
 592
 593                 if ($reshared) {
 594                         $type = 'Announce';
 595                 } elseif ($item['verb'] == ACTIVITY_POST) {
 596                         if ($item['created'] == $item['edited']) {
 597                                 $type = 'Create';
 598                         } else {
 599                                 $type = 'Update';
 600                         }
 601                 } elseif ($item['verb'] == ACTIVITY_LIKE) {
 602                         $type = 'Like';
 603                 } elseif ($item['verb'] == ACTIVITY_DISLIKE) {
 604                         $type = 'Dislike';
 605                 } elseif ($item['verb'] == ACTIVITY_ATTEND) {
 606                         $type = 'Accept';
 607                 } elseif ($item['verb'] == ACTIVITY_ATTENDNO) {
 608                         $type = 'Reject';
 609                 } elseif ($item['verb'] == ACTIVITY_ATTENDMAYBE) {
 610                         $type = 'TentativeAccept';
 611                 } elseif ($item['verb'] == ACTIVITY_FOLLOW) {
 612                         $type = 'Follow';
 613                 } else {
 614                         $type = '';
 615                 }
 616
 617                 return $type;
 618         }
 619
 620         /**
 621          * Creates the activity or fetches it from the cache
 622          *
 623          * @param integer $item_id
 624          * @param boolean $force Force new cache entry
 625          *
 626          * @return array with the activity
 627          * @throws \Exception
 628          */
 629         public static function createCachedActivityFromItem($item_id, $force = false)
 630         {
 631                 $cachekey = 'APDelivery:createActivity:' . $item_id;
 632
 633                 if (!$force) {
 634                         $data = Cache::get($cachekey);
 635                         if (!is_null($data)) {
 636                                 return $data;
 637                         }
 638                 }
 639
 640                 $data = ActivityPub\Transmitter::createActivityFromItem($item_id);
 641
 642                 Cache::set($cachekey, $data, Cache::QUARTER_HOUR);
 643                 return $data;
 644         }
 645
 646         /**
 647          * Creates an activity array for a given item id
 648          *
 649          * @param integer $item_id
 650          * @param boolean $object_mode Is the activity item is used inside another object?
 651          *
 652          * @return array of activity
 653          * @throws \Exception
 654          */
 655         public static function createActivityFromItem($item_id, $object_mode = false)
 656         {
 657                 $item = Item::selectFirst([], ['id' => $item_id, 'parent-network' => Protocol::NATIVE_SUPPORT]);
 658
 659                 if (!DBA::isResult($item)) {
 660                         return false;
 661                 }
 662
 663                 if ($item['wall'] && ($item['uri'] == $item['parent-uri'])) {
 664                         $owner = User::getOwnerDataById($item['uid']);
 665                         if (($owner['account-type'] == User::ACCOUNT_TYPE_COMMUNITY) && ($item['author-link'] != $owner['url'])) {
 666                                 $type = 'Announce';
 667
 668                                 // Disguise forum posts as reshares. Will later be converted to a real announce
 669                                 $item['body'] = share_header($item['author-name'], $item['author-link'], $item['author-avatar'],
 670                                         $item['guid'], $item['created'], $item['plink']) . $item['body'] . '[/share]';
 671                         }
 672                 }
 673
 674                 if (empty($type)) {
 675                         $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
 676                         $conversation = DBA::selectFirst('conversation', ['source'], $condition);
 677                         if (DBA::isResult($conversation)) {
 678                                 $data = json_decode($conversation['source']);
 679                                 if (!empty($data)) {
 680                                         return $data;
 681                                 }
 682                         }
 683
 684                         $type = self::getTypeOfItem($item);
 685                 }
 686
 687                 if (!$object_mode) {
 688                         $data = ['@context' => ActivityPub::CONTEXT];
 689
 690                         if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
 691                                 $type = 'Undo';
 692                         } elseif ($item['deleted']) {
 693                                 $type = 'Delete';
 694                         }
 695                 } else {
 696                         $data = [];
 697                 }
 698
 699                 $data['id'] = $item['uri'] . '#' . $type;
 700                 $data['type'] = $type;
 701
 702                 if (Item::isForumPost($item) && ($type != 'Announce')) {
 703                         $data['actor'] = $item['author-link'];
 704                 } else {
 705                         $data['actor'] = $item['owner-link'];
 706                 }
 707
 708                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
 709
 710                 $data['instrument'] = ['type' => 'Service', 'name' => BaseObject::getApp()->getUserAgent()];
 711
 712                 $data = array_merge($data, self::createPermissionBlockForItem($item, false));
 713
 714                 if (in_array($data['type'], ['Create', 'Update', 'Delete'])) {
 715                         $data['object'] = self::createNote($item);
 716                 } elseif ($data['type'] == 'Announce') {
 717                         $data = self::createAnnounce($item, $data);
 718                 } elseif ($data['type'] == 'Follow') {
 719                         $data['object'] = $item['parent-uri'];
 720                 } elseif ($data['type'] == 'Undo') {
 721                         $data['object'] = self::createActivityFromItem($item_id, true);
 722                 } else {
 723                         $data['diaspora:guid'] = $item['guid'];
 724                         if (!empty($item['signed_text'])) {
 725                                 $data['diaspora:like'] = $item['signed_text'];
 726                         }
 727                         $data['object'] = $item['thr-parent'];
 728                 }
 729
 730                 if (!empty($item['contact-uid'])) {
 731                         $uid = $item['contact-uid'];
 732                 } else {
 733                         $uid = $item['uid'];
 734                 }
 735
 736                 $owner = User::getOwnerDataById($uid);
 737
 738                 if (!$object_mode && !empty($owner)) {
 739                         return LDSignature::sign($data, $owner);
 740                 } else {
 741                         return $data;
 742                 }
 743
 744                 /// @todo Create "conversation" entry
 745         }
 746
 747         /**
 748          * Creates an object array for a given item id
 749          *
 750          * @param integer $item_id
 751          *
 752          * @return array with the object data
 753          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 754          * @throws \ImagickException
 755          */
 756         public static function createObjectFromItemID($item_id)
 757         {
 758                 $item = Item::selectFirst([], ['id' => $item_id, 'parent-network' => Protocol::NATIVE_SUPPORT]);
 759
 760                 if (!DBA::isResult($item)) {
 761                         return false;
 762                 }
 763
 764                 $data = ['@context' => ActivityPub::CONTEXT];
 765                 $data = array_merge($data, self::createNote($item));
 766
 767                 return $data;
 768         }
 769
 770         /**
 771          * Creates a location entry for a given item array
 772          *
 773          * @param array $item
 774          *
 775          * @return array with location array
 776          */
 777         private static function createLocation($item)
 778         {
 779                 $location = ['type' => 'Place'];
 780
 781                 if (!empty($item['location'])) {
 782                         $location['name'] = $item['location'];
 783                 }
 784
 785                 $coord = [];
 786
 787                 if (empty($item['coord'])) {
 788                         $coord = Map::getCoordinates($item['location']);
 789                 } else {
 790                         $coords = explode(' ', $item['coord']);
 791                         if (count($coords) == 2) {
 792                                 $coord = ['lat' => $coords[0], 'lon' => $coords[1]];
 793                         }
 794                 }
 795
 796                 if (!empty($coord['lat']) && !empty($coord['lon'])) {
 797                         $location['latitude'] = $coord['lat'];
 798                         $location['longitude'] = $coord['lon'];
 799                 }
 800
 801                 return $location;
 802         }
 803
 804         /**
 805          * Returns a tag array for a given item array
 806          *
 807          * @param array $item
 808          *
 809          * @return array of tags
 810          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 811          */
 812         private static function createTagList($item)
 813         {
 814                 $tags = [];
 815
 816                 $terms = Term::tagArrayFromItemId($item['id'], [Term::HASHTAG, Term::MENTION, Term::IMPLICIT_MENTION]);
 817                 foreach ($terms as $term) {
 818                         if ($term['type'] == Term::HASHTAG) {
 819                                 $url = System::baseUrl() . '/search?tag=' . urlencode($term['term']);
 820                                 $tags[] = ['type' => 'Hashtag', 'href' => $url, 'name' => '#' . $term['term']];
 821                         } elseif ($term['type'] == Term::MENTION || $term['type'] == Term::IMPLICIT_MENTION) {
 822                                 $contact = Contact::getDetailsByURL($term['url']);
 823                                 if (!empty($contact['addr'])) {
 824                                         $mention = '@' . $contact['addr'];
 825                                 } else {
 826                                         $mention = '@' . $term['url'];
 827                                 }
 828
 829                                 $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
 830                         }
 831                 }
 832                 return $tags;
 833         }
 834
 835         /**
 836          * Adds attachment data to the JSON document
 837          *
 838          * @param array  $item Data of the item that is to be posted
 839          * @param string $type Object type
 840          *
 841          * @return array with attachment data
 842          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 843          */
 844         private static function createAttachmentList($item, $type)
 845         {
 846                 $attachments = [];
 847
 848                 $arr = explode('[/attach],', $item['attach']);
 849                 if (count($arr)) {
 850                         foreach ($arr as $r) {
 851                                 $matches = false;
 852                                 $cnt = preg_match('|\[attach\]href=\"(.*?)\" length=\"(.*?)\" type=\"(.*?)\" title=\"(.*?)\"|', $r, $matches);
 853                                 if ($cnt) {
 854                                         $attributes = ['type' => 'Document',
 855                                                         'mediaType' => $matches[3],
 856                                                         'url' => $matches[1],
 857                                                         'name' => null];
 858
 859                                         if (trim($matches[4]) != '') {
 860                                                 $attributes['name'] = trim($matches[4]);
 861                                         }
 862
 863                                         $attachments[] = $attributes;
 864                                 }
 865                         }
 866                 }
 867
 868                 if ($type != 'Note') {
 869                         return $attachments;
 870                 }
 871
 872                 // Simplify image codes
 873                 $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $item['body']);
 874
 875                 // Grab all pictures and create attachments out of them
 876                 if (preg_match_all("/\[img\]([^\[\]]*)\[\/img\]/Usi", $body, $pictures)) {
 877                         foreach ($pictures[1] as $picture) {
 878                                 $imgdata = Image::getInfoFromURL($picture);
 879                                 if ($imgdata) {
 880                                         $attachments[] = ['type' => 'Document',
 881                                                 'mediaType' => $imgdata['mime'],
 882                                                 'url' => $picture,
 883                                                 'name' => null];
 884                                 }
 885                         }
 886                 }
 887
 888                 return $attachments;
 889         }
 890
 891         /**
 892          * @brief Callback function to replace a Friendica style mention in a mention that is used on AP
 893          *
 894          * @param array $match Matching values for the callback
 895          * @return string Replaced mention
 896          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 897          */
 898         private static function mentionCallback($match)
 899         {
 900                 if (empty($match[1])) {
 901                         return '';
 902                 }
 903
 904                 $data = Contact::getDetailsByURL($match[1]);
 905                 if (empty($data['nick'])) {
 906                         return $match[0];
 907                 }
 908
 909                 return '@[url=' . $data['url'] . ']' . $data['nick'] . '[/url]';
 910         }
 911
 912         /**
 913          * Remove image elements and replaces them with links to the image
 914          *
 915          * @param string $body
 916          *
 917          * @return string with replaced elements
 918          */
 919         private static function removePictures($body)
 920         {
 921                 // Simplify image codes
 922                 $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $body);
 923
 924                 $body = preg_replace("/\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]/Usi", '[url]$1[/url]', $body);
 925                 $body = preg_replace("/\[img\]([^\[\]]*)\[\/img\]/Usi", '[url]$1[/url]', $body);
 926
 927                 return $body;
 928         }
 929
 930         /**
 931          * Fetches the "context" value for a givem item array from the "conversation" table
 932          *
 933          * @param array $item
 934          *
 935          * @return string with context url
 936          * @throws \Exception
 937          */
 938         private static function fetchContextURLForItem($item)
 939         {
 940                 $conversation = DBA::selectFirst('conversation', ['conversation-href', 'conversation-uri'], ['item-uri' => $item['parent-uri']]);
 941                 if (DBA::isResult($conversation) && !empty($conversation['conversation-href'])) {
 942                         $context_uri = $conversation['conversation-href'];
 943                 } elseif (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
 944                         $context_uri = $conversation['conversation-uri'];
 945                 } else {
 946                         $context_uri = $item['parent-uri'] . '#context';
 947                 }
 948                 return $context_uri;
 949         }
 950
 951         /**
 952          * Returns if the post contains sensitive content ("nsfw")
 953          *
 954          * @param integer $item_id
 955          *
 956          * @return boolean
 957          * @throws \Exception
 958          */
 959         private static function isSensitive($item_id)
 960         {
 961                 $condition = ['otype' => TERM_OBJ_POST, 'oid' => $item_id, 'type' => TERM_HASHTAG, 'term' => 'nsfw'];
 962                 return DBA::exists('term', $condition);
 963         }
 964
 965         /**
 966          * Creates event data
 967          *
 968          * @param array $item
 969          *
 970          * @return array with the event data
 971          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 972          */
 973         public static function createEvent($item)
 974         {
 975                 $event = [];
 976                 $event['name'] = $item['event-summary'];
 977                 $event['content'] = BBCode::convert($item['event-desc'], false, 7);
 978                 $event['startTime'] = DateTimeFormat::utc($item['event-start'] . '+00:00', DateTimeFormat::ATOM);
 979
 980                 if (!$item['event-nofinish']) {
 981                         $event['endTime'] = DateTimeFormat::utc($item['event-finish'] . '+00:00', DateTimeFormat::ATOM);
 982                 }
 983
 984                 if (!empty($item['event-location'])) {
 985                         $item['location'] = $item['event-location'];
 986                         $event['location'] = self::createLocation($item);
 987                 }
 988
 989                 return $event;
 990         }
 991
 992         /**
 993          * Creates a note/article object array
 994          *
 995          * @param array $item
 996          *
 997          * @return array with the object data
 998          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 999          * @throws \ImagickException
1000          */
1001         public static function createNote($item)
1002         {
1003                 if ($item['event-type'] == 'event') {
1004                         $type = 'Event';
1005                 } elseif (!empty($item['title'])) {
1006                         $type = 'Article';
1007                 } else {
1008                         $type = 'Note';
1009                 }
1010
1011                 if ($item['deleted']) {
1012                         $type = 'Tombstone';
1013                 }
1014
1015                 $data = [];
1016                 $data['id'] = $item['uri'];
1017                 $data['type'] = $type;
1018
1019                 if ($item['deleted']) {
1020                         return $data;
1021                 }
1022
1023                 $data['summary'] = null; // Ignore by now
1024
1025                 if ($item['uri'] != $item['thr-parent']) {
1026                         $data['inReplyTo'] = $item['thr-parent'];
1027                 } else {
1028                         $data['inReplyTo'] = null;
1029                 }
1030
1031                 $data['diaspora:guid'] = $item['guid'];
1032                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1033
1034                 if ($item['created'] != $item['edited']) {
1035                         $data['updated'] = DateTimeFormat::utc($item['edited'] . '+00:00', DateTimeFormat::ATOM);
1036                 }
1037
1038                 $data['url'] = $item['plink'];
1039                 $data['attributedTo'] = $item['author-link'];
1040                 $data['sensitive'] = self::isSensitive($item['id']);
1041                 $data['context'] = self::fetchContextURLForItem($item);
1042
1043                 if (!empty($item['title'])) {
1044                         $data['name'] = BBCode::toPlaintext($item['title'], false);
1045                 }
1046
1047                 $permission_block = self::createPermissionBlockForItem($item, false);
1048
1049                 $body = $item['body'];
1050
1051                 if (empty($item['uid']) || !Feature::isEnabled($item['uid'], 'explicit_mentions')) {
1052                         $body = self::prependMentions($body, $permission_block);
1053                 }
1054
1055                 if ($type == 'Note') {
1056                         $body = self::removePictures($body);
1057                 }
1058
1059                 if ($type == 'Event') {
1060                         $data = array_merge($data, self::createEvent($item));
1061                 } else {
1062                         $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1063                         $body = preg_replace_callback($regexp, ['self', 'mentionCallback'], $body);
1064
1065                         $data['content'] = BBCode::convert($body, false, 7);
1066                 }
1067
1068                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
1069
1070                 if (!empty($item['signed_text']) && ($item['uri'] != $item['thr-parent'])) {
1071                         $data['diaspora:comment'] = $item['signed_text'];
1072                 }
1073
1074                 $data['attachment'] = self::createAttachmentList($item, $type);
1075                 $data['tag'] = self::createTagList($item);
1076
1077                 if (empty($data['location']) && (!empty($item['coord']) || !empty($item['location']))) {
1078                         $data['location'] = self::createLocation($item);
1079                 }
1080
1081                 if (!empty($item['app'])) {
1082                         $data['generator'] = ['type' => 'Application', 'name' => $item['app']];
1083                 }
1084
1085                 $data = array_merge($data, $permission_block);
1086
1087                 return $data;
1088         }
1089
1090         /**
1091          * Creates an announce object entry
1092          *
1093          * @param array $item
1094          * @param array $data activity data
1095          *
1096          * @return array with activity data
1097          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1098          * @throws \ImagickException
1099          */
1100         private static function createAnnounce($item, $data)
1101         {
1102                 $announce = api_share_as_retweet($item);
1103                 if (empty($announce['plink'])) {
1104                         $data['type'] = 'Create';
1105                         $data['object'] = self::createNote($item);
1106                         return $data;
1107                 }
1108
1109                 // Fetch the original id of the object
1110                 $activity = ActivityPub::fetchContent($announce['plink'], $item['uid']);
1111                 if (!empty($activity)) {
1112                         $ldactivity = JsonLD::compact($activity);
1113                         $id = JsonLD::fetchElement($ldactivity, '@id');
1114                         if (!empty($id)) {
1115                                 $data['object'] = $id;
1116                                 return $data;
1117                         }
1118                 }
1119
1120                 $data['type'] = 'Create';
1121                 $data['object'] = self::createNote($item);
1122                 return $data;
1123         }
1124
1125         /**
1126          * Creates an activity id for a given contact id
1127          *
1128          * @param integer $cid Contact ID of target
1129          *
1130          * @return bool|string activity id
1131          */
1132         public static function activityIDFromContact($cid)
1133         {
1134                 $contact = DBA::selectFirst('contact', ['uid', 'id', 'created'], ['id' => $cid]);
1135                 if (!DBA::isResult($contact)) {
1136                         return false;
1137                 }
1138
1139                 $hash = hash('ripemd128', $contact['uid'].'-'.$contact['id'].'-'.$contact['created']);
1140                 $uuid = substr($hash, 0, 8). '-' . substr($hash, 8, 4) . '-' . substr($hash, 12, 4) . '-' . substr($hash, 16, 4) . '-' . substr($hash, 20, 12);
1141                 return System::baseUrl() . '/activity/' . $uuid;
1142         }
1143
1144         /**
1145          * Transmits a contact suggestion to a given inbox
1146          *
1147          * @param integer $uid           User ID
1148          * @param string  $inbox         Target inbox
1149          * @param integer $suggestion_id Suggestion ID
1150          *
1151          * @return boolean was the transmission successful?
1152          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1153          */
1154         public static function sendContactSuggestion($uid, $inbox, $suggestion_id)
1155         {
1156                 $owner = User::getOwnerDataById($uid);
1157
1158                 $suggestion = DBA::selectFirst('fsuggest', ['url', 'note', 'created'], ['id' => $suggestion_id]);
1159
1160                 $data = ['@context' => ActivityPub::CONTEXT,
1161                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
1162                         'type' => 'Announce',
1163                         'actor' => $owner['url'],
1164                         'object' => $suggestion['url'],
1165                         'content' => $suggestion['note'],
1166                         'instrument' => ['type' => 'Service', 'name' => BaseObject::getApp()->getUserAgent()],
1167                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1168                         'cc' => []];
1169
1170                 $signed = LDSignature::sign($data, $owner);
1171
1172                 Logger::log('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1173                 return HTTPSignature::transmit($signed, $inbox, $uid);
1174         }
1175
1176         /**
1177          * Transmits a profile relocation to a given inbox
1178          *
1179          * @param integer $uid   User ID
1180          * @param string  $inbox Target inbox
1181          *
1182          * @return boolean was the transmission successful?
1183          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1184          */
1185         public static function sendProfileRelocation($uid, $inbox)
1186         {
1187                 $owner = User::getOwnerDataById($uid);
1188
1189                 $data = ['@context' => ActivityPub::CONTEXT,
1190                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
1191                         'type' => 'dfrn:relocate',
1192                         'actor' => $owner['url'],
1193                         'object' => $owner['url'],
1194                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1195                         'instrument' => ['type' => 'Service', 'name' => BaseObject::getApp()->getUserAgent()],
1196                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1197                         'cc' => []];
1198
1199                 $signed = LDSignature::sign($data, $owner);
1200
1201                 Logger::log('Deliver profile relocation for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1202                 return HTTPSignature::transmit($signed, $inbox, $uid);
1203         }
1204
1205         /**
1206          * Transmits a profile deletion to a given inbox
1207          *
1208          * @param integer $uid   User ID
1209          * @param string  $inbox Target inbox
1210          *
1211          * @return boolean was the transmission successful?
1212          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1213          */
1214         public static function sendProfileDeletion($uid, $inbox)
1215         {
1216                 $owner = User::getOwnerDataById($uid);
1217
1218                 if (empty($owner)) {
1219                         Logger::error('No owner data found, the deletion message cannot be processed.', ['user' => $uid]);
1220                         return false;
1221                 }
1222
1223                 if (empty($owner['uprvkey'])) {
1224                         Logger::error('No private key for owner found, the deletion message cannot be processed.', ['user' => $uid]);
1225                         return false;
1226                 }
1227
1228                 $data = ['@context' => ActivityPub::CONTEXT,
1229                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
1230                         'type' => 'Delete',
1231                         'actor' => $owner['url'],
1232                         'object' => $owner['url'],
1233                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1234                         'instrument' => ['type' => 'Service', 'name' => BaseObject::getApp()->getUserAgent()],
1235                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1236                         'cc' => []];
1237
1238                 $signed = LDSignature::sign($data, $owner);
1239
1240                 Logger::log('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1241                 return HTTPSignature::transmit($signed, $inbox, $uid);
1242         }
1243
1244         /**
1245          * Transmits a profile change to a given inbox
1246          *
1247          * @param integer $uid   User ID
1248          * @param string  $inbox Target inbox
1249          *
1250          * @return boolean was the transmission successful?
1251          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1252          * @throws \ImagickException
1253          */
1254         public static function sendProfileUpdate($uid, $inbox)
1255         {
1256                 $owner = User::getOwnerDataById($uid);
1257                 $profile = APContact::getByURL($owner['url']);
1258
1259                 $data = ['@context' => ActivityPub::CONTEXT,
1260                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
1261                         'type' => 'Update',
1262                         'actor' => $owner['url'],
1263                         'object' => self::getProfile($uid),
1264                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1265                         'instrument' => ['type' => 'Service', 'name' => BaseObject::getApp()->getUserAgent()],
1266                         'to' => [$profile['followers']],
1267                         'cc' => []];
1268
1269                 $signed = LDSignature::sign($data, $owner);
1270
1271                 Logger::log('Deliver profile update for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1272                 return HTTPSignature::transmit($signed, $inbox, $uid);
1273         }
1274
1275         /**
1276          * Transmits a given activity to a target
1277          *
1278          * @param string  $activity Type name
1279          * @param string  $target   Target profile
1280          * @param integer $uid      User ID
1281          * @return bool
1282          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1283          * @throws \ImagickException
1284          * @throws \Exception
1285          */
1286         public static function sendActivity($activity, $target, $uid, $id = '')
1287         {
1288                 $profile = APContact::getByURL($target);
1289
1290                 $owner = User::getOwnerDataById($uid);
1291
1292                 if (empty($id)) {
1293                         $id = System::baseUrl() . '/activity/' . System::createGUID();
1294                 }
1295
1296                 $data = ['@context' => ActivityPub::CONTEXT,
1297                         'id' => $id,
1298                         'type' => $activity,
1299                         'actor' => $owner['url'],
1300                         'object' => $profile['url'],
1301                         'instrument' => ['type' => 'Service', 'name' => BaseObject::getApp()->getUserAgent()],
1302                         'to' => [$profile['url']]];
1303
1304                 Logger::log('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid, Logger::DEBUG);
1305
1306                 $signed = LDSignature::sign($data, $owner);
1307                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1308         }
1309
1310         /**
1311          * Transmits a "follow object" activity to a target
1312          * This is a preparation for sending automated "follow" requests when receiving "Announce" messages
1313          *
1314          * @param string  $object Object URL
1315          * @param string  $target Target profile
1316          * @param integer $uid    User ID
1317          * @return bool
1318          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1319          * @throws \ImagickException
1320          * @throws \Exception
1321          */
1322         public static function sendFollowObject($object, $target, $uid = 0)
1323         {
1324                 $profile = APContact::getByURL($target);
1325
1326                 if (empty($uid)) {
1327                         // Fetch the list of administrators
1328                         $admin_mail = explode(',', str_replace(' ', '', Config::get('config', 'admin_email')));
1329
1330                         // We need to use some user as a sender. It doesn't care who it will send. We will use an administrator account.
1331                         $condition = ['verified' => true, 'blocked' => false, 'account_removed' => false, 'account_expired' => false, 'email' => $admin_mail];
1332                         $first_user = DBA::selectFirst('user', ['uid'], $condition);
1333                         $uid = $first_user['uid'];
1334                 }
1335
1336                 $condition = ['verb' => ACTIVITY_FOLLOW, 'uid' => 0, 'parent-uri' => $object,
1337                         'author-id' => Contact::getPublicIdByUserId($uid)];
1338                 if (Item::exists($condition)) {
1339                         Logger::log('Follow for ' . $object . ' for user ' . $uid . ' does already exist.', Logger::DEBUG);
1340                         return false;
1341                 }
1342
1343                 $owner = User::getOwnerDataById($uid);
1344
1345                 $data = ['@context' => ActivityPub::CONTEXT,
1346                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
1347                         'type' => 'Follow',
1348                         'actor' => $owner['url'],
1349                         'object' => $object,
1350                         'instrument' => ['type' => 'Service', 'name' => BaseObject::getApp()->getUserAgent()],
1351                         'to' => [$profile['url']]];
1352
1353                 Logger::log('Sending follow ' . $object . ' to ' . $target . ' for user ' . $uid, Logger::DEBUG);
1354
1355                 $signed = LDSignature::sign($data, $owner);
1356                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1357         }
1358
1359         /**
1360          * Transmit a message that the contact request had been accepted
1361          *
1362          * @param string  $target Target profile
1363          * @param         $id
1364          * @param integer $uid    User ID
1365          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1366          * @throws \ImagickException
1367          */
1368         public static function sendContactAccept($target, $id, $uid)
1369         {
1370                 $profile = APContact::getByURL($target);
1371
1372                 $owner = User::getOwnerDataById($uid);
1373                 $data = ['@context' => ActivityPub::CONTEXT,
1374                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
1375                         'type' => 'Accept',
1376                         'actor' => $owner['url'],
1377                         'object' => ['id' => $id, 'type' => 'Follow',
1378                                 'actor' => $profile['url'],
1379                                 'object' => $owner['url']],
1380                         'instrument' => ['type' => 'Service', 'name' => BaseObject::getApp()->getUserAgent()],
1381                         'to' => [$profile['url']]];
1382
1383                 Logger::log('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id, Logger::DEBUG);
1384
1385                 $signed = LDSignature::sign($data, $owner);
1386                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1387         }
1388
1389         /**
1390          * Reject a contact request or terminates the contact relation
1391          *
1392          * @param string  $target Target profile
1393          * @param         $id
1394          * @param integer $uid    User ID
1395          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1396          * @throws \ImagickException
1397          */
1398         public static function sendContactReject($target, $id, $uid)
1399         {
1400                 $profile = APContact::getByURL($target);
1401
1402                 $owner = User::getOwnerDataById($uid);
1403                 $data = ['@context' => ActivityPub::CONTEXT,
1404                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
1405                         'type' => 'Reject',
1406                         'actor' => $owner['url'],
1407                         'object' => ['id' => $id, 'type' => 'Follow',
1408                                 'actor' => $profile['url'],
1409                                 'object' => $owner['url']],
1410                         'instrument' => ['type' => 'Service', 'name' => BaseObject::getApp()->getUserAgent()],
1411                         'to' => [$profile['url']]];
1412
1413                 Logger::log('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id, Logger::DEBUG);
1414
1415                 $signed = LDSignature::sign($data, $owner);
1416                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1417         }
1418
1419         /**
1420          * Transmits a message that we don't want to follow this contact anymore
1421          *
1422          * @param string  $target Target profile
1423          * @param integer $uid    User ID
1424          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1425          * @throws \ImagickException
1426          * @throws \Exception
1427          */
1428         public static function sendContactUndo($target, $cid, $uid)
1429         {
1430                 $profile = APContact::getByURL($target);
1431
1432                 $object_id = self::activityIDFromContact($cid);
1433                 if (empty($object_id)) {
1434                         return;
1435                 }
1436
1437                 $id = System::baseUrl() . '/activity/' . System::createGUID();
1438
1439                 $owner = User::getOwnerDataById($uid);
1440                 $data = ['@context' => ActivityPub::CONTEXT,
1441                         'id' => $id,
1442                         'type' => 'Undo',
1443                         'actor' => $owner['url'],
1444                         'object' => ['id' => $object_id, 'type' => 'Follow',
1445                                 'actor' => $owner['url'],
1446                                 'object' => $profile['url']],
1447                         'instrument' => ['type' => 'Service', 'name' => BaseObject::getApp()->getUserAgent()],
1448                         'to' => [$profile['url']]];
1449
1450                 Logger::log('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id, Logger::DEBUG);
1451
1452                 $signed = LDSignature::sign($data, $owner);
1453                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1454         }
1455
1456         private static function prependMentions($body, array $permission_block)
1457         {
1458                 if (Config::get('system', 'disable_implicit_mentions')) {
1459                         return $body;
1460                 }
1461
1462                 $mentions = [];
1463
1464                 foreach ($permission_block['to'] as $profile_url) {
1465                         $profile = Contact::getDetailsByURL($profile_url);
1466                         if (!empty($profile['addr'])
1467                                 && $profile['contact-type'] != Contact::TYPE_COMMUNITY
1468                                 && !strstr($body, $profile['addr'])
1469                                 && !strstr($body, $profile_url)
1470                         ) {
1471                                 $mentions[] = '@[url=' . $profile_url . ']' . $profile['nick'] . '[/url]';
1472                         }
1473                 }
1474
1475                 $mentions[] = $body;
1476
1477                 return implode(' ', $mentions);
1478         }
1479 }