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