src/Protocol/ActivityPub.php

   1 <?php
   2 /**
   3  * @file src/Protocol/ActivityPub.php
   4  */
   5 namespace Friendica\Protocol;
   6
   7 use Friendica\Database\DBA;
   8 use Friendica\Core\System;
   9 use Friendica\BaseObject;
  10 use Friendica\Util\Network;
  11 use Friendica\Util\HTTPSignature;
  12 use Friendica\Core\Protocol;
  13 use Friendica\Model\Conversation;
  14 use Friendica\Model\Contact;
  15 use Friendica\Model\Item;
  16 use Friendica\Model\Term;
  17 use Friendica\Model\User;
  18 use Friendica\Util\DateTimeFormat;
  19 use Friendica\Util\Crypto;
  20 use Friendica\Content\Text\BBCode;
  21 use Friendica\Content\Text\HTML;
  22 use Friendica\Util\JsonLD;
  23 use Friendica\Util\LDSignature;
  24
  25 /**
  26  * @brief ActivityPub Protocol class
  27  * The ActivityPub Protocol is a message exchange protocol defined by the W3C.
  28  * https://www.w3.org/TR/activitypub/
  29  * https://www.w3.org/TR/activitystreams-core/
  30  * https://www.w3.org/TR/activitystreams-vocabulary/
  31  *
  32  * https://blog.joinmastodon.org/2018/06/how-to-implement-a-basic-activitypub-server/
  33  * https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/
  34  *
  35  * Digest: https://tools.ietf.org/html/rfc5843
  36  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  37  * https://github.com/digitalbazaar/php-json-ld
  38  *
  39  * Part of the code for HTTP signing is taken from the Osada project.
  40  * https://framagit.org/macgirvin/osada
  41  *
  42  * To-do:
  43  *
  44  * Receiver:
  45  * - Activities: Dislike, Update, Delete
  46  * - Object Types: Person, Tombstome
  47  *
  48  * Transmitter:
  49  * - Activities: Like, Dislike, Update, Delete
  50  * - Object Tyoes: Article, Announce, Person, Tombstone
  51  *
  52  * General:
  53  * - Message distribution
  54  * - Endpoints: Outbox, Object, Follower, Following
  55  * - General cleanup
  56  */
  57 class ActivityPub
  58 {
  59         const PUBLIC = 'https://www.w3.org/ns/activitystreams#Public';
  60
  61         public static function isRequest()
  62         {
  63                 return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
  64                         stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
  65         }
  66
  67         /**
  68          * Return the ActivityPub profile of the given user
  69          *
  70          * @param integer $uid User ID
  71          * @return array
  72          */
  73         public static function profile($uid)
  74         {
  75                 $accounttype = ['Person', 'Organization', 'Service', 'Group', 'Application'];
  76                 $condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
  77                         'account_removed' => false, 'verified' => true];
  78                 $fields = ['guid', 'nickname', 'pubkey', 'account-type', 'page-flags'];
  79                 $user = DBA::selectFirst('user', $fields, $condition);
  80                 if (!DBA::isResult($user)) {
  81                         return [];
  82                 }
  83
  84                 $fields = ['locality', 'region', 'country-name'];
  85                 $profile = DBA::selectFirst('profile', $fields, ['uid' => $uid, 'is-default' => true]);
  86                 if (!DBA::isResult($profile)) {
  87                         return [];
  88                 }
  89
  90                 $fields = ['name', 'url', 'location', 'about', 'avatar'];
  91                 $contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
  92                 if (!DBA::isResult($contact)) {
  93                         return [];
  94                 }
  95
  96                 $data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  97                         ['vcard' => 'http://www.w3.org/2006/vcard/ns#', 'uuid' => 'http://schema.org/identifier',
  98                         'sensitive' => 'as:sensitive', 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers']]];
  99
 100                 $data['id'] = $contact['url'];
 101                 $data['uuid'] = $user['guid'];
 102                 $data['type'] = $accounttype[$user['account-type']];
 103                 $data['following'] = System::baseUrl() . '/following/' . $user['nickname'];
 104                 $data['followers'] = System::baseUrl() . '/followers/' . $user['nickname'];
 105                 $data['inbox'] = System::baseUrl() . '/inbox/' . $user['nickname'];
 106                 $data['outbox'] = System::baseUrl() . '/outbox/' . $user['nickname'];
 107                 $data['preferredUsername'] = $user['nickname'];
 108                 $data['name'] = $contact['name'];
 109                 $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $profile['country-name'],
 110                         'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
 111                 $data['summary'] = $contact['about'];
 112                 $data['url'] = $contact['url'];
 113                 $data['manuallyApprovesFollowers'] = in_array($user['page-flags'], [Contact::PAGE_NORMAL, Contact::PAGE_PRVGROUP]);
 114                 $data['publicKey'] = ['id' => $contact['url'] . '#main-key',
 115                         'owner' => $contact['url'],
 116                         'publicKeyPem' => $user['pubkey']];
 117                 $data['endpoints'] = ['sharedInbox' => System::baseUrl() . '/inbox'];
 118                 $data['icon'] = ['type' => 'Image',
 119                         'url' => $contact['avatar']];
 120
 121                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
 122                 return $data;
 123         }
 124
 125         public static function createPermissionBlockForItem($item)
 126         {
 127                 $data = ['to' => [], 'cc' => []];
 128
 129                 $terms = Term::tagArrayFromItemId($item['id']);
 130
 131                 if (!$item['private']) {
 132                         $data['to'][] = self::PUBLIC;
 133                         $data['cc'][] = System::baseUrl() . '/followers/' . $item['author-nick'];
 134
 135                         foreach ($terms as $term) {
 136                                 if ($term['type'] != TERM_MENTION) {
 137                                         continue;
 138                                 }
 139                                 $profile = self::fetchprofile($term['url']);
 140                                 if (!empty($profile)) {
 141                                         $data['cc'][] = $profile['url'];
 142                                 }
 143                         }
 144                 } else {
 145                         //$data['cc'][] = System::baseUrl() . '/followers/' . $item['author-nick'];
 146                         $receiver_list = Item::enumeratePermissions($item);
 147
 148                         $mentioned = [];
 149
 150                         foreach ($terms as $term) {
 151                                 if ($term['type'] != TERM_MENTION) {
 152                                         continue;
 153                                 }
 154                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 155                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 156                                         $contact = DBA::selectFirst('contact', ['url'], ['id' => $cid, 'network' => Protocol::ACTIVITYPUB]);
 157                                         $data['to'][] = $contact['url'];
 158                                 }
 159                         }
 160
 161                         foreach ($receiver_list as $receiver) {
 162                                 $contact = DBA::selectFirst('contact', ['url'], ['id' => $receiver, 'network' => Protocol::ACTIVITYPUB]);
 163                                 $data['cc'][] = $contact['url'];
 164                         }
 165
 166                         if (empty($data['to'])) {
 167                                 $data['to'] = $data['cc'];
 168                                 $data['cc'] = [];
 169                         }
 170                 }
 171
 172                 return $data;
 173         }
 174
 175         public static function fetchTargetInboxes($item)
 176         {
 177                 $inboxes = [];
 178
 179                 $terms = Term::tagArrayFromItemId($item['id']);
 180                 if (!$item['private']) {
 181                         $contacts = DBA::select('contact', ['notify', 'batch'], ['uid' => $item['uid'],
 182                                         'rel' => [Contact::FOLLOWER, Contact::FRIEND], 'network' => Protocol::ACTIVITYPUB]);
 183                         while ($contact = DBA::fetch($contacts)) {
 184                                 $contact = defaults($contact, 'batch', $contact['notify']);
 185                                 $inboxes[$contact] = $contact;
 186                         }
 187                         DBA::close($contacts);
 188
 189                         foreach ($terms as $term) {
 190                                 if ($term['type'] != TERM_MENTION) {
 191                                         continue;
 192                                 }
 193                                 $profile = self::fetchprofile($term['url']);
 194                                 if (!empty($profile)) {
 195                                         $target = defaults($profile, 'sharedinbox', $profile['inbox']);
 196                                         $inboxes[$target] = $target;
 197                                 }
 198                         }
 199                 } else {
 200                         $receiver_list = Item::enumeratePermissions($item);
 201
 202                         $mentioned = [];
 203
 204                         foreach ($terms as $term) {
 205                                 if ($term['type'] != TERM_MENTION) {
 206                                         continue;
 207                                 }
 208                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 209                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 210                                         $contact = DBA::selectFirst('contact', ['url'], ['id' => $cid, 'network' => Protocol::ACTIVITYPUB]);
 211                                         $profile = self::fetchprofile($contact['url']);
 212                                         if (!empty($profile['network'])) {
 213                                                 $target = defaults($profile, 'sharedinbox', $profile['inbox']);
 214                                                 $inboxes[$target] = $target;
 215                                         }
 216                                 }
 217                         }
 218
 219                         foreach ($receiver_list as $receiver) {
 220                                 $contact = DBA::selectFirst('contact', ['url'], ['id' => $receiver, 'network' => Protocol::ACTIVITYPUB]);
 221                                 $profile = self::fetchprofile($contact['url']);
 222                                 if (!empty($profile['network'])) {
 223                                         $target = defaults($profile, 'sharedinbox', $profile['inbox']);
 224                                         $inboxes[$target] = $target;
 225                                 }
 226                         }
 227                 }
 228
 229                 $profile = self::fetchprofile($item['author-link']);
 230                 if (!empty($profile['sharedinbox'])) {
 231                         unset($inboxes[$profile['sharedinbox']]);
 232                 }
 233
 234                 if (!empty($profile['inbox'])) {
 235                         unset($inboxes[$profile['inbox']]);
 236                 }
 237
 238                 return $inboxes;
 239         }
 240
 241         public static function createActivityFromItem($item_id)
 242         {
 243                 $item = Item::selectFirst([], ['id' => $item_id]);
 244
 245                 if (!DBA::isResult($item)) {
 246                         return false;
 247                 }
 248
 249                 $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
 250                 $conversation = DBA::selectFirst('conversation', ['source'], $condition);
 251                 if (DBA::isResult($conversation)) {
 252                         $data = json_decode($conversation['source']);
 253                         if (!empty($data)) {
 254                                 return $data;
 255                         }
 256                 }
 257
 258                 $data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
 259                         ['ostatus' => 'http://ostatus.org#', 'sensitive' => 'as:sensitive',
 260                         'Hashtag' => 'as:Hashtag', 'atomUri' => 'ostatus:atomUri',
 261                         'conversation' => 'ostatus:conversation',
 262                         'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri']]];
 263
 264                 $data['type'] = 'Create';
 265                 $data['id'] = $item['uri'] . '#activity';
 266                 $data['actor'] = $item['author-link'];
 267
 268                 $data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
 269
 270                 if ($item["created"] != $item["edited"]) {
 271                         $data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
 272                 }
 273
 274                 $data = array_merge($data, ActivityPub::createPermissionBlockForItem($item));
 275
 276                 $data['object'] = self::createNote($item);
 277
 278                 $owner = User::getOwnerDataById($item['uid']);
 279
 280                 return LDSignature::sign($data, $owner);
 281         }
 282
 283         public static function createObjectFromItemID($item_id)
 284         {
 285                 $item = Item::selectFirst([], ['id' => $item_id]);
 286
 287                 if (!DBA::isResult($item)) {
 288                         return false;
 289                 }
 290
 291                 $data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
 292                         ['ostatus' => 'http://ostatus.org#', 'sensitive' => 'as:sensitive',
 293                         'Hashtag' => 'as:Hashtag', 'atomUri' => 'ostatus:atomUri',
 294                         'conversation' => 'ostatus:conversation',
 295                         'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri']]];
 296
 297                 $data = array_merge($data, self::createNote($item));
 298
 299
 300                 return $data;
 301         }
 302
 303         private static function createTagList($item)
 304         {
 305                 $tags = [];
 306
 307                 $terms = Term::tagArrayFromItemId($item['id']);
 308                 foreach ($terms as $term) {
 309                         if ($term['type'] == TERM_MENTION) {
 310                                 $contact = Contact::getDetailsByURL($term['url']);
 311                                 if (!empty($contact['addr'])) {
 312                                         $mention = '@' . $contact['addr'];
 313                                 } else {
 314                                         $mention = '@' . $term['url'];
 315                                 }
 316
 317                                 $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
 318                         }
 319                 }
 320
 321                 return $tags;
 322         }
 323
 324         public static function createNote($item)
 325         {
 326                 $data = [];
 327                 $data['type'] = 'Note';
 328                 $data['id'] = $item['uri'];
 329
 330                 if ($item['uri'] != $item['thr-parent']) {
 331                         $data['inReplyTo'] = $item['thr-parent'];
 332                 }
 333
 334                 $conversation = DBA::selectFirst('conversation', ['conversation-uri'], ['item-uri' => $item['parent-uri']]);
 335                 if (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
 336                         $conversation_uri = $conversation['conversation-uri'];
 337                 } else {
 338                         $conversation_uri = $item['parent-uri'];
 339                 }
 340
 341                 $data['context'] = $data['conversation'] = $conversation_uri;
 342                 $data['actor'] = $item['author-link'];
 343                 $data = array_merge($data, ActivityPub::createPermissionBlockForItem($item));
 344                 $data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
 345
 346                 if ($item["created"] != $item["edited"]) {
 347                         $data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
 348                 }
 349
 350                 $data['attributedTo'] = $item['author-link'];
 351                 $data['name'] = BBCode::convert($item['title'], false, 7);
 352                 $data['content'] = BBCode::convert($item['body'], false, 7);
 353                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
 354                 $data['summary'] = ''; // Ignore by now
 355                 $data['sensitive'] = false; // - Query NSFW
 356                 //$data['emoji'] = []; // Ignore by now
 357                 $data['tag'] = self::createTagList($item);
 358                 $data['attachment'] = []; // @ToDo
 359                 return $data;
 360         }
 361
 362         public static function transmitActivity($activity, $target, $uid)
 363         {
 364                 $profile = self::fetchprofile($target);
 365
 366                 $owner = User::getOwnerDataById($uid);
 367
 368                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 369                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
 370                         'type' => $activity,
 371                         'actor' => $owner['url'],
 372                         'object' => $profile['url'],
 373                         'to' => $profile['url']];
 374
 375                 logger('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid, LOGGER_DEBUG);
 376
 377                 $signed = LDSignature::sign($data, $owner);
 378                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
 379         }
 380
 381         public static function transmitContactAccept($target, $id, $uid)
 382         {
 383                 $profile = self::fetchprofile($target);
 384
 385                 $owner = User::getOwnerDataById($uid);
 386                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 387                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
 388                         'type' => 'Accept',
 389                         'actor' => $owner['url'],
 390                         'object' => ['id' => $id, 'type' => 'Follow',
 391                                 'actor' => $profile['url'],
 392                                 'object' => $owner['url']],
 393                         'to' => $profile['url']];
 394
 395                 logger('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
 396
 397                 $signed = LDSignature::sign($data, $owner);
 398                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
 399         }
 400
 401         public static function transmitContactReject($target, $id, $uid)
 402         {
 403                 $profile = self::fetchprofile($target);
 404
 405                 $owner = User::getOwnerDataById($uid);
 406                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 407                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
 408                         'type' => 'Reject',
 409                         'actor' => $owner['url'],
 410                         'object' => ['id' => $id, 'type' => 'Follow',
 411                                 'actor' => $profile['url'],
 412                                 'object' => $owner['url']],
 413                         'to' => $profile['url']];
 414
 415                 logger('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
 416
 417                 $signed = LDSignature::sign($data, $owner);
 418                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
 419         }
 420
 421         public static function transmitContactUndo($target, $uid)
 422         {
 423                 $profile = self::fetchprofile($target);
 424
 425                 $id = System::baseUrl() . '/activity/' . System::createGUID();
 426
 427                 $owner = User::getOwnerDataById($uid);
 428                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 429                         'id' => $id,
 430                         'type' => 'Undo',
 431                         'actor' => $owner['url'],
 432                         'object' => ['id' => $id, 'type' => 'Follow',
 433                                 'actor' => $owner['url'],
 434                                 'object' => $profile['url']],
 435                         'to' => $profile['url']];
 436
 437                 logger('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
 438
 439                 $signed = LDSignature::sign($data, $owner);
 440                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
 441         }
 442
 443         /**
 444          * Fetches ActivityPub content from the given url
 445          *
 446          * @param string $url content url
 447          * @return array
 448          */
 449         public static function fetchContent($url)
 450         {
 451                 $ret = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json, application/ld+json']);
 452                 if (!$ret['success'] || empty($ret['body'])) {
 453                         return;
 454                 }
 455
 456                 return json_decode($ret['body'], true);
 457         }
 458
 459         /**
 460          * Resolves the profile url from the address by using webfinger
 461          *
 462          * @param string $addr profile address (user@domain.tld)
 463          * @return string url
 464          */
 465         private static function addrToUrl($addr)
 466         {
 467                 $addr_parts = explode('@', $addr);
 468                 if (count($addr_parts) != 2) {
 469                         return false;
 470                 }
 471
 472                 $webfinger = 'https://' . $addr_parts[1] . '/.well-known/webfinger?resource=acct:' . urlencode($addr);
 473
 474                 $ret = Network::curl($webfinger, false, $redirects, ['accept_content' => 'application/jrd+json,application/json']);
 475                 if (!$ret['success'] || empty($ret['body'])) {
 476                         return false;
 477                 }
 478
 479                 $data = json_decode($ret['body'], true);
 480
 481                 if (empty($data['links'])) {
 482                         return false;
 483                 }
 484
 485                 foreach ($data['links'] as $link) {
 486                         if (empty($link['href']) || empty($link['rel']) || empty($link['type'])) {
 487                                 continue;
 488                         }
 489
 490                         if (($link['rel'] == 'self') && ($link['type'] == 'application/activity+json')) {
 491                                 return $link['href'];
 492                         }
 493                 }
 494
 495                 return false;
 496         }
 497
 498         public static function fetchprofile($url, $update = false)
 499         {
 500                 if (empty($url)) {
 501                         return false;
 502                 }
 503
 504                 if (!$update) {
 505                         $apcontact = DBA::selectFirst('apcontact', [], ['url' => $url]);
 506                         if (DBA::isResult($apcontact)) {
 507                                 return $apcontact;
 508                         }
 509
 510                         $apcontact = DBA::selectFirst('apcontact', [], ['alias' => $url]);
 511                         if (DBA::isResult($apcontact)) {
 512                                 return $apcontact;
 513                         }
 514
 515                         $apcontact = DBA::selectFirst('apcontact', [], ['addr' => $url]);
 516                         if (DBA::isResult($apcontact)) {
 517                                 return $apcontact;
 518                         }
 519                 }
 520
 521                 if (empty(parse_url($url, PHP_URL_SCHEME))) {
 522                         $url = self::addrToUrl($url);
 523                         if (empty($url)) {
 524                                 return false;
 525                         }
 526                 }
 527
 528                 $data = self::fetchContent($url);
 529
 530                 if (empty($data) || empty($data['id']) || empty($data['inbox'])) {
 531                         return false;
 532                 }
 533
 534                 $apcontact = [];
 535                 $apcontact['url'] = $data['id'];
 536                 $apcontact['uuid'] = defaults($data, 'uuid', null);
 537                 $apcontact['type'] = defaults($data, 'type', null);
 538                 $apcontact['following'] = defaults($data, 'following', null);
 539                 $apcontact['followers'] = defaults($data, 'followers', null);
 540                 $apcontact['inbox'] = defaults($data, 'inbox', null);
 541                 $apcontact['outbox'] = defaults($data, 'outbox', null);
 542                 $apcontact['sharedinbox'] = JsonLD::fetchElement($data, 'endpoints', 'sharedInbox');
 543                 $apcontact['nick'] = defaults($data, 'preferredUsername', null);
 544                 $apcontact['name'] = defaults($data, 'name', $apcontact['nick']);
 545                 $apcontact['about'] = defaults($data, 'summary', '');
 546                 $apcontact['photo'] = JsonLD::fetchElement($data, 'icon', 'url');
 547                 $apcontact['alias'] = JsonLD::fetchElement($data, 'url', 'href');
 548
 549                 $parts = parse_url($apcontact['url']);
 550                 unset($parts['scheme']);
 551                 unset($parts['path']);
 552                 $apcontact['addr'] = $apcontact['nick'] . '@' . str_replace('//', '', Network::unparseURL($parts));
 553
 554                 $apcontact['pubkey'] = trim(JsonLD::fetchElement($data, 'publicKey', 'publicKeyPem'));
 555
 556                 // To-Do
 557                 // manuallyApprovesFollowers
 558
 559                 // Unhandled
 560                 // @context, tag, attachment, image, nomadicLocations, signature, following, followers, featured, movedTo, liked
 561
 562                 // Unhandled from Misskey
 563                 // sharedInbox, isCat
 564
 565                 // Unhandled from Kroeg
 566                 // kroeg:blocks, updated
 567
 568                 // Check if the address is resolvable
 569                 if (self::addrToUrl($apcontact['addr']) == $apcontact['url']) {
 570                         $parts = parse_url($apcontact['url']);
 571                         unset($parts['path']);
 572                         $apcontact['baseurl'] = Network::unparseURL($parts);
 573                 } else {
 574                         $apcontact['addr'] = null;
 575                 }
 576
 577                 if ($apcontact['url'] == $apcontact['alias']) {
 578                         $apcontact['alias'] = null;
 579                 }
 580
 581                 $apcontact['updated'] = DateTimeFormat::utcNow();
 582
 583                 DBA::update('apcontact', $apcontact, ['url' => $url], true);
 584
 585                 return $apcontact;
 586         }
 587
 588         /**
 589          * Fetches a profile from the given url into an array that is compatible to Probe::uri
 590          *
 591          * @param string $url profile url
 592          * @return array
 593          */
 594         public static function probeProfile($url)
 595         {
 596                 $apcontact = self::fetchprofile($url, true);
 597                 if (empty($apcontact)) {
 598                         return false;
 599                 }
 600
 601                 $profile = ['network' => Protocol::ACTIVITYPUB];
 602                 $profile['nick'] = $apcontact['nick'];
 603                 $profile['name'] = $apcontact['name'];
 604                 $profile['guid'] = $apcontact['uuid'];
 605                 $profile['url'] = $apcontact['url'];
 606                 $profile['addr'] = $apcontact['addr'];
 607                 $profile['alias'] = $apcontact['alias'];
 608                 $profile['photo'] = $apcontact['photo'];
 609                 // $profile['community']
 610                 // $profile['keywords']
 611                 // $profile['location']
 612                 $profile['about'] = $apcontact['about'];
 613                 $profile['batch'] = $apcontact['sharedinbox'];
 614                 $profile['notify'] = $apcontact['inbox'];
 615                 $profile['poll'] = $apcontact['outbox'];
 616                 $profile['pubkey'] = $apcontact['pubkey'];
 617                 $profile['baseurl'] = $apcontact['baseurl'];
 618
 619                 // Remove all "null" fields
 620                 foreach ($profile as $field => $content) {
 621                         if (is_null($content)) {
 622                                 unset($profile[$field]);
 623                         }
 624                 }
 625
 626                 return $profile;
 627         }
 628
 629         public static function processInbox($body, $header, $uid)
 630         {
 631                 logger('Incoming message for user ' . $uid, LOGGER_DEBUG);
 632
 633                 if (!HTTPSignature::verifyAP($body, $header)) {
 634                         logger('Invalid signature, message will be discarded.', LOGGER_DEBUG);
 635                         return;
 636                 }
 637
 638                 $activity = json_decode($body, true);
 639
 640                 if (!is_array($activity)) {
 641                         logger('Invalid body.', LOGGER_DEBUG);
 642                         return;
 643                 }
 644
 645                 self::processActivity($activity, $body, $uid);
 646         }
 647
 648         public static function fetchOutbox($url, $uid)
 649         {
 650                 $data = self::fetchContent($url);
 651                 if (empty($data)) {
 652                         return;
 653                 }
 654
 655                 if (!empty($data['orderedItems'])) {
 656                         $items = $data['orderedItems'];
 657                 } elseif (!empty($data['first']['orderedItems'])) {
 658                         $items = $data['first']['orderedItems'];
 659                 } elseif (!empty($data['first'])) {
 660                         self::fetchOutbox($data['first'], $uid);
 661                         return;
 662                 } else {
 663                         $items = [];
 664                 }
 665
 666                 foreach ($items as $activity) {
 667                         self::processActivity($activity, '', $uid);
 668                 }
 669         }
 670
 671         private static function prepareObjectData($activity, $uid)
 672         {
 673                 $actor = JsonLD::fetchElement($activity, 'actor', 'id');
 674                 if (empty($actor)) {
 675                         logger('Empty actor', LOGGER_DEBUG);
 676                         return [];
 677                 }
 678
 679                 // Fetch all receivers from to, cc, bto and bcc
 680                 $receivers = self::getReceivers($activity, $actor);
 681
 682                 // When it is a delivery to a personal inbox we add that user to the receivers
 683                 if (!empty($uid)) {
 684                         $owner = User::getOwnerDataById($uid);
 685                         $additional = ['uid:' . $uid => $uid];
 686                         $receivers = array_merge($receivers, $additional);
 687                 }
 688
 689                 logger('Receivers: ' . json_encode($receivers), LOGGER_DEBUG);
 690
 691                 $unsigned = true;
 692
 693                 if (LDSignature::isSigned($activity)) {
 694                         if (!LDSignature::isVerified($activity)) {
 695                                 logger('Invalid signature. Quitting here.', LOGGER_DEBUG);
 696                                 return [];
 697                         }
 698                         logger('Valid signature.', LOGGER_DEBUG);
 699                         $unsigned = false;
 700                 } elseif (!in_array(0, $receivers)) {
 701                         /// @todo Add some checks to only accept unsigned private posts directly from the actor
 702                         $unsigned = false;
 703                         logger('Private post without signature.', LOGGER_DEBUG);
 704                 } else {
 705                         logger('Public post without signature. Object data will be fetched.', LOGGER_DEBUG);
 706                 }
 707
 708                 if (is_string($activity['object'])) {
 709                         $object_url = $activity['object'];
 710                 } elseif (!empty($activity['object']['id'])) {
 711                         $object_url = $activity['object']['id'];
 712                 } else {
 713                         logger('No object found', LOGGER_DEBUG);
 714                         return [];
 715                 }
 716
 717                 // Fetch the content only on activities where this matters
 718                 if (in_array($activity['type'], ['Create', 'Update', 'Announce'])) {
 719                         $object_data = self::fetchObject($object_url, $activity['object'], $unsigned);
 720                         if (empty($object_data)) {
 721                                 logger("Object data couldn't be processed", LOGGER_DEBUG);
 722                                 return [];
 723                         }
 724                 } elseif ($activity['type'] == 'Accept') {
 725                         $object_data = [];
 726                         $object_data['object_type'] = JsonLD::fetchElement($activity, 'object', 'type');
 727                         $object_data['object'] = JsonLD::fetchElement($activity, 'object', 'actor');
 728                 } elseif ($activity['type'] == 'Undo') {
 729                         $object_data = [];
 730                         $object_data['object_type'] = JsonLD::fetchElement($activity, 'object', 'type');
 731                         $object_data['object'] = JsonLD::fetchElement($activity, 'object', 'object');
 732                 } elseif (in_array($activity['type'], ['Like', 'Dislike'])) {
 733                         // Create a mostly empty array out of the activity data (instead of the object).
 734                         // This way we later don't have to check for the existence of ech individual array element.
 735                         $object_data = self::processCommonData($activity);
 736                         $object_data['name'] = $activity['type'];
 737                         $object_data['author'] = $activity['actor'];
 738                         $object_data['object'] = $object_url;
 739                 } elseif ($activity['type'] == 'Follow') {
 740                         $object_data['id'] = $activity['id'];
 741                         $object_data['object'] = $object_url;
 742                 } else {
 743                         $object_data = [];
 744                 }
 745
 746                 $object_data = self::addActivityFields($object_data, $activity);
 747
 748                 $object_data['type'] = $activity['type'];
 749                 $object_data['owner'] = $actor;
 750                 $object_data['receiver'] = array_merge(defaults($object_data, 'receiver', []), $receivers);
 751
 752                 return $object_data;
 753         }
 754
 755         private static function processActivity($activity, $body = '', $uid = null)
 756         {
 757                 if (empty($activity['type'])) {
 758                         logger('Empty type', LOGGER_DEBUG);
 759                         return;
 760                 }
 761
 762                 if (empty($activity['object'])) {
 763                         logger('Empty object', LOGGER_DEBUG);
 764                         return;
 765                 }
 766
 767                 if (empty($activity['actor'])) {
 768                         logger('Empty actor', LOGGER_DEBUG);
 769                         return;
 770
 771                 }
 772
 773                 // Non standard
 774                 // title, atomUri, context_id, statusnetConversationId
 775
 776                 // To-Do?
 777                 // context, location, signature;
 778
 779                 logger('Processing activity: ' . $activity['type'], LOGGER_DEBUG);
 780
 781                 $object_data = self::prepareObjectData($activity, $uid);
 782                 if (empty($object_data)) {
 783                         logger('No object data found', LOGGER_DEBUG);
 784                         return;
 785                 }
 786
 787                 switch ($activity['type']) {
 788                         case 'Create':
 789                         case 'Announce':
 790                                 self::createItem($object_data, $body);
 791                                 break;
 792
 793                         case 'Like':
 794                                 self::likeItem($object_data, $body);
 795                                 break;
 796
 797                         case 'Dislike':
 798                                 break;
 799
 800                         case 'Update':
 801                                 break;
 802
 803                         case 'Delete':
 804                                 break;
 805
 806                         case 'Follow':
 807                                 self::followUser($object_data);
 808                                 break;
 809
 810                         case 'Accept':
 811                                 if ($object_data['object_type'] == 'Follow') {
 812                                         self::acceptFollowUser($object_data);
 813                                 }
 814                                 break;
 815
 816                         case 'Undo':
 817                                 if ($object_data['object_type'] == 'Follow') {
 818                                         self::undoFollowUser($object_data);
 819                                 }
 820                                 break;
 821
 822                         default:
 823                                 logger('Unknown activity: ' . $activity['type'], LOGGER_DEBUG);
 824                                 break;
 825                 }
 826         }
 827
 828         private static function getReceivers($activity, $actor)
 829         {
 830                 $receivers = [];
 831
 832                 if (!empty($actor)) {
 833                         $profile = self::fetchprofile($actor);
 834                         $followers = defaults($profile, 'followers', '');
 835
 836                         logger('Actor: ' . $actor . ' - Followers: ' . $followers, LOGGER_DEBUG);
 837                 } else {
 838                         logger('Empty actor', LOGGER_DEBUG);
 839                         $followers = '';
 840                 }
 841
 842                 $elements = ['to', 'cc', 'bto', 'bcc'];
 843                 foreach ($elements as $element) {
 844                         if (empty($activity[$element])) {
 845                                 continue;
 846                         }
 847
 848                         // The receiver can be an arror or a string
 849                         if (is_string($activity[$element])) {
 850                                 $activity[$element] = [$activity[$element]];
 851                         }
 852
 853                         foreach ($activity[$element] as $receiver) {
 854                                 if ($receiver == self::PUBLIC) {
 855                                         $receivers['uid:0'] = 0;
 856                                 }
 857
 858                                 if (($receiver == self::PUBLIC) && !empty($actor)) {
 859                                         // This will most likely catch all OStatus connections to Mastodon
 860                                         $condition = ['alias' => [$actor, normalise_link($actor)], 'rel' => [Contact::SHARING, Contact::FRIEND]];
 861                                         $contacts = DBA::select('contact', ['uid'], $condition);
 862                                         while ($contact = DBA::fetch($contacts)) {
 863                                                 if ($contact['uid'] != 0) {
 864                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
 865                                                 }
 866                                         }
 867                                         DBA::close($contacts);
 868                                 }
 869
 870                                 if (in_array($receiver, [$followers, self::PUBLIC]) && !empty($actor)) {
 871                                         $condition = ['nurl' => normalise_link($actor), 'rel' => [Contact::SHARING, Contact::FRIEND],
 872                                                 'network' => Protocol::ACTIVITYPUB];
 873                                         $contacts = DBA::select('contact', ['uid'], $condition);
 874                                         while ($contact = DBA::fetch($contacts)) {
 875                                                 if ($contact['uid'] != 0) {
 876                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
 877                                                 }
 878                                         }
 879                                         DBA::close($contacts);
 880                                         continue;
 881                                 }
 882
 883                                 $condition = ['self' => true, 'nurl' => normalise_link($receiver)];
 884                                 $contact = DBA::selectFirst('contact', ['uid'], $condition);
 885                                 if (!DBA::isResult($contact)) {
 886                                         continue;
 887                                 }
 888                                 $receivers['uid:' . $contact['uid']] = $contact['uid'];
 889                         }
 890                 }
 891                 return $receivers;
 892         }
 893
 894         private static function addActivityFields($object_data, $activity)
 895         {
 896                 if (!empty($activity['published']) && empty($object_data['published'])) {
 897                         $object_data['published'] = $activity['published'];
 898                 }
 899
 900                 if (!empty($activity['updated']) && empty($object_data['updated'])) {
 901                         $object_data['updated'] = $activity['updated'];
 902                 }
 903
 904                 if (!empty($activity['inReplyTo']) && empty($object_data['parent-uri'])) {
 905                         $object_data['parent-uri'] = JsonLD::fetchElement($activity, 'inReplyTo', 'id');
 906                 }
 907
 908                 if (!empty($activity['instrument'])) {
 909                         $object_data['service'] = JsonLD::fetchElement($activity, 'instrument', 'name', 'type', 'Service');
 910                 }
 911                 return $object_data;
 912         }
 913
 914         private static function fetchObject($object_url, $object = [], $unsigned = true)
 915         {
 916                 if ($unsigned) {
 917                         $data = self::fetchContent($object_url);
 918                         if (empty($data)) {
 919                                 logger('Empty content for ' . $object_url . ', check if content is available locally.', LOGGER_DEBUG);
 920                                 $data = $object_url;
 921                                 $data = $object;
 922                         }
 923                 } else {
 924                         logger('Using original object for url ' . $object_url, LOGGER_DEBUG);
 925                         $data = $object;
 926                 }
 927
 928                 if (is_string($data)) {
 929                         $item = Item::selectFirst([], ['uri' => $data]);
 930                         if (!DBA::isResult($item)) {
 931                                 logger('Object with url ' . $data . ' was not found locally.', LOGGER_DEBUG);
 932                                 return false;
 933                         }
 934                         logger('Using already stored item for url ' . $object_url, LOGGER_DEBUG);
 935                         $data = self::createNote($item);
 936                 }
 937
 938                 if (empty($data['type'])) {
 939                         logger('Empty type', LOGGER_DEBUG);
 940                         return false;
 941                 } else {
 942                         $type = $data['type'];
 943                         logger('Type ' . $type, LOGGER_DEBUG);
 944                 }
 945
 946                 if (in_array($type, ['Note', 'Article', 'Video'])) {
 947                         $common = self::processCommonData($data);
 948                 }
 949
 950                 switch ($type) {
 951                         case 'Note':
 952                                 return array_merge($common, self::processNote($data));
 953                         case 'Article':
 954                                 return array_merge($common, self::processArticle($data));
 955                         case 'Video':
 956                                 return array_merge($common, self::processVideo($data));
 957
 958                         case 'Announce':
 959                                 if (empty($data['object'])) {
 960                                         return false;
 961                                 }
 962                                 return self::fetchObject($data['object']);
 963
 964                         case 'Person':
 965                         case 'Tombstone':
 966                                 break;
 967
 968                         default:
 969                                 logger('Unknown object type: ' . $data['type'], LOGGER_DEBUG);
 970                                 break;
 971                 }
 972         }
 973
 974         private static function processCommonData(&$object)
 975         {
 976                 if (empty($object['id'])) {
 977                         return false;
 978                 }
 979
 980                 $object_data = [];
 981                 $object_data['type'] = $object['type'];
 982                 $object_data['uri'] = $object['id'];
 983
 984                 if (!empty($object['inReplyTo'])) {
 985                         $object_data['reply-to-uri'] = JsonLD::fetchElement($object, 'inReplyTo', 'id');
 986                 } else {
 987                         $object_data['reply-to-uri'] = $object_data['uri'];
 988                 }
 989
 990                 $object_data['published'] = defaults($object, 'published', null);
 991                 $object_data['updated'] = defaults($object, 'updated', $object_data['published']);
 992
 993                 if (empty($object_data['published']) && !empty($object_data['updated'])) {
 994                         $object_data['published'] = $object_data['updated'];
 995                 }
 996
 997                 $object_data['uuid'] = defaults($object, 'uuid', null);
 998                 $object_data['owner'] = $object_data['author'] = JsonLD::fetchElement($object, 'attributedTo', 'id');
 999                 $object_data['context'] = defaults($object, 'context', null);
1000                 $object_data['conversation'] = defaults($object, 'conversation', null);
1001                 $object_data['sensitive'] = defaults($object, 'sensitive', null);
1002                 $object_data['name'] = defaults($object, 'title', null);
1003                 $object_data['name'] = defaults($object, 'name', $object_data['name']);
1004                 $object_data['summary'] = defaults($object, 'summary', null);
1005                 $object_data['content'] = defaults($object, 'content', null);
1006                 $object_data['source'] = defaults($object, 'source', null);
1007                 $object_data['location'] = JsonLD::fetchElement($object, 'location', 'name', 'type', 'Place');
1008                 $object_data['attachments'] = defaults($object, 'attachment', null);
1009                 $object_data['tags'] = defaults($object, 'tag', null);
1010                 $object_data['service'] = JsonLD::fetchElement($object, 'instrument', 'name', 'type', 'Service');
1011                 $object_data['alternate-url'] = JsonLD::fetchElement($object, 'url', 'href');
1012                 $object_data['receiver'] = self::getReceivers($object, $object_data['owner']);
1013
1014                 // Unhandled
1015                 // @context, type, actor, signature, mediaType, duration, replies, icon
1016
1017                 // Also missing: (Defined in the standard, but currently unused)
1018                 // audience, preview, endTime, startTime, generator, image
1019
1020                 return $object_data;
1021         }
1022
1023         private static function processNote($object)
1024         {
1025                 $object_data = [];
1026
1027                 // To-Do?
1028                 // emoji, atomUri, inReplyToAtomUri
1029
1030                 // Unhandled
1031                 // contentMap, announcement_count, announcements, context_id, likes, like_count
1032                 // inReplyToStatusId, shares, quoteUrl, statusnetConversationId
1033
1034                 return $object_data;
1035         }
1036
1037         private static function processArticle($object)
1038         {
1039                 $object_data = [];
1040
1041                 return $object_data;
1042         }
1043
1044         private static function processVideo($object)
1045         {
1046                 $object_data = [];
1047
1048                 // To-Do?
1049                 // category, licence, language, commentsEnabled
1050
1051                 // Unhandled
1052                 // views, waitTranscoding, state, support, subtitleLanguage
1053                 // likes, dislikes, shares, comments
1054
1055                 return $object_data;
1056         }
1057
1058         private static function convertMentions($body)
1059         {
1060                 $URLSearchString = "^\[\]";
1061                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
1062
1063                 return $body;
1064         }
1065
1066         private static function constructTagList($tags, $sensitive)
1067         {
1068                 if (empty($tags)) {
1069                         return '';
1070                 }
1071
1072                 $tag_text = '';
1073                 foreach ($tags as $tag) {
1074                         if (in_array($tag['type'], ['Mention', 'Hashtag'])) {
1075                                 if (!empty($tag_text)) {
1076                                         $tag_text .= ',';
1077                                 }
1078
1079                                 if (empty($tag['href'])) {
1080                                         //$tag['href']
1081                                         logger('Blubb!');
1082                                 }
1083
1084                                 $tag_text .= substr($tag['name'], 0, 1) . '[url=' . $tag['href'] . ']' . substr($tag['name'], 1) . '[/url]';
1085                         }
1086                 }
1087
1088                 /// @todo add nsfw for $sensitive
1089
1090                 return $tag_text;
1091         }
1092
1093         private static function constructAttachList($attachments, $item)
1094         {
1095                 if (empty($attachments)) {
1096                         return $item;
1097                 }
1098
1099                 foreach ($attachments as $attach) {
1100                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
1101                         if ($filetype == 'image') {
1102                                 $item['body'] .= "\n[img]".$attach['url'].'[/img]';
1103                         } else {
1104                                 if (!empty($item["attach"])) {
1105                                         $item["attach"] .= ',';
1106                                 } else {
1107                                         $item["attach"] = '';
1108                                 }
1109                                 if (!isset($attach['length'])) {
1110                                         $attach['length'] = "0";
1111                                 }
1112                                 $item["attach"] .= '[attach]href="'.$attach['url'].'" length="'.$attach['length'].'" type="'.$attach['mediaType'].'" title="'.defaults($attach, 'name', '').'"[/attach]';
1113                         }
1114                 }
1115
1116                 return $item;
1117         }
1118
1119         private static function createItem($activity, $body)
1120         {
1121                 $item = [];
1122                 $item['verb'] = ACTIVITY_POST;
1123                 $item['parent-uri'] = $activity['reply-to-uri'];
1124
1125                 if ($activity['reply-to-uri'] == $activity['uri']) {
1126                         $item['gravity'] = GRAVITY_PARENT;
1127                         $item['object-type'] = ACTIVITY_OBJ_NOTE;
1128                 } else {
1129                         $item['gravity'] = GRAVITY_COMMENT;
1130                         $item['object-type'] = ACTIVITY_OBJ_COMMENT;
1131                 }
1132
1133                 if (($activity['uri'] != $activity['reply-to-uri']) && !Item::exists(['uri' => $activity['reply-to-uri']])) {
1134                         logger('Parent ' . $activity['reply-to-uri'] . ' not found. Try to refetch it.');
1135                         self::fetchMissingActivity($activity['reply-to-uri'], $activity);
1136                 }
1137
1138                 self::postItem($activity, $item, $body);
1139         }
1140
1141         private static function likeItem($activity, $body)
1142         {
1143                 $item = [];
1144                 $item['verb'] = ACTIVITY_LIKE;
1145                 $item['parent-uri'] = $activity['object'];
1146                 $item['gravity'] = GRAVITY_ACTIVITY;
1147                 $item['object-type'] = ACTIVITY_OBJ_NOTE;
1148
1149                 self::postItem($activity, $item, $body);
1150         }
1151
1152         private static function postItem($activity, $item, $body)
1153         {
1154                 /// @todo What to do with $activity['context']?
1155
1156                 $item['network'] = Protocol::ACTIVITYPUB;
1157                 $item['private'] = !in_array(0, $activity['receiver']);
1158                 $item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
1159                 $item['owner-id'] = Contact::getIdForURL($activity['owner'], 0, true);
1160                 $item['uri'] = $activity['uri'];
1161                 $item['created'] = $activity['published'];
1162                 $item['edited'] = $activity['updated'];
1163                 $item['guid'] = $activity['uuid'];
1164                 $item['title'] = HTML::toBBCode($activity['name']);
1165                 $item['content-warning'] = HTML::toBBCode($activity['summary']);
1166                 $item['body'] = self::convertMentions(HTML::toBBCode($activity['content']));
1167                 $item['location'] = $activity['location'];
1168                 $item['tag'] = self::constructTagList($activity['tags'], $activity['sensitive']);
1169                 $item['app'] = $activity['service'];
1170                 $item['plink'] = defaults($activity, 'alternate-url', $item['uri']);
1171
1172                 $item = self::constructAttachList($activity['attachments'], $item);
1173
1174                 $source = JsonLD::fetchElement($activity, 'source', 'content', 'mediaType', 'text/bbcode');
1175                 if (!empty($source)) {
1176                         $item['body'] = $source;
1177                 }
1178
1179                 $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
1180                 $item['source'] = $body;
1181                 $item['conversation-uri'] = $activity['conversation'];
1182
1183                 foreach ($activity['receiver'] as $receiver) {
1184                         $item['uid'] = $receiver;
1185                         $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
1186
1187                         if (($receiver != 0) && empty($item['contact-id'])) {
1188                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
1189                         }
1190
1191                         $item_id = Item::insert($item);
1192                         logger('Storing for user ' . $item['uid'] . ': ' . $item_id);
1193                 }
1194         }
1195
1196         private static function fetchMissingActivity($url, $child)
1197         {
1198                 $object = ActivityPub::fetchContent($url);
1199                 if (empty($object)) {
1200                         logger('Activity ' . $url . ' was not fetchable, aborting.');
1201                         return;
1202                 }
1203
1204                 $activity = [];
1205                 $activity['@context'] = $object['@context'];
1206                 unset($object['@context']);
1207                 $activity['id'] = $object['id'];
1208                 $activity['to'] = defaults($object, 'to', []);
1209                 $activity['cc'] = defaults($object, 'cc', []);
1210                 $activity['actor'] = $child['author'];
1211                 $activity['object'] = $object;
1212                 $activity['published'] = $object['published'];
1213                 $activity['type'] = 'Create';
1214                 self::processActivity($activity);
1215                 logger('Activity ' . $url . ' had been fetched and processed.');
1216         }
1217
1218         private static function getUserOfObject($object)
1219         {
1220                 $self = DBA::selectFirst('contact', ['uid'], ['nurl' => normalise_link($object), 'self' => true]);
1221                 if (!DBA::isResult($self)) {
1222                         return false;
1223                 } else {
1224                         return $self['uid'];
1225                 }
1226         }
1227
1228         private static function followUser($activity)
1229         {
1230                 $uid = self::getUserOfObject($activity['object']);
1231                 if (empty($uid)) {
1232                         return;
1233                 }
1234
1235                 $owner = User::getOwnerDataById($uid);
1236
1237                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1238                 if (!empty($cid)) {
1239                         $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1240                 } else {
1241                         $contact = false;
1242                 }
1243
1244                 $item = ['author-id' => Contact::getIdForURL($activity['owner']),
1245                         'author-link' => $activity['owner']];
1246
1247                 Contact::addRelationship($owner, $contact, $item);
1248                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1249                 if (empty($cid)) {
1250                         return;
1251                 }
1252
1253                 $contact = DBA::selectFirst('contact', ['network'], ['id' => $cid]);
1254                 if ($contact['network'] != Protocol::ACTIVITYPUB) {
1255                         Contact::updateFromProbe($cid, Protocol::ACTIVITYPUB);
1256                 }
1257
1258                 DBA::update('contact', ['hub-verify' => $activity['id']], ['id' => $cid]);
1259                 logger('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1260         }
1261
1262         private static function acceptFollowUser($activity)
1263         {
1264                 $uid = self::getUserOfObject($activity['object']);
1265                 if (empty($uid)) {
1266                         return;
1267                 }
1268
1269                 $owner = User::getOwnerDataById($uid);
1270
1271                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1272                 if (empty($cid)) {
1273                         logger('No contact found for ' . $activity['owner'], LOGGER_DEBUG);
1274                         return;
1275                 }
1276
1277                 $fields = ['pending' => false];
1278
1279                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1280                 if ($contact['rel'] == Contact::FOLLOWER) {
1281                         $fields['rel'] = Contact::FRIEND;
1282                 }
1283
1284                 $condition = ['id' => $cid];
1285                 DBA::update('contact', $fields, $condition);
1286                 logger('Accept contact request from contact ' . $cid . ' for user ' . $uid, LOGGER_DEBUG);
1287         }
1288
1289         private static function undoFollowUser($activity)
1290         {
1291                 $uid = self::getUserOfObject($activity['object']);
1292                 if (empty($uid)) {
1293                         return;
1294                 }
1295
1296                 $owner = User::getOwnerDataById($uid);
1297
1298                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1299                 if (empty($cid)) {
1300                         logger('No contact found for ' . $activity['owner'], LOGGER_DEBUG);
1301                         return;
1302                 }
1303
1304                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1305                 if (!DBA::isResult($contact)) {
1306                         return;
1307                 }
1308
1309                 Contact::removeFollower($owner, $contact);
1310                 logger('Undo following request from contact ' . $cid . ' for user ' . $uid, LOGGER_DEBUG);
1311         }
1312 }