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\User;
  17 use Friendica\Util\DateTimeFormat;
  18 use Friendica\Util\Crypto;
  19 use Friendica\Content\Text\BBCode;
  20 use Friendica\Content\Text\HTML;
  21 use Friendica\Network\Probe;
  22
  23 /**
  24  * @brief ActivityPub Protocol class
  25  * The ActivityPub Protocol is a message exchange protocol defined by the W3C.
  26  * https://www.w3.org/TR/activitypub/
  27  * https://www.w3.org/TR/activitystreams-core/
  28  * https://www.w3.org/TR/activitystreams-vocabulary/
  29  *
  30  * https://blog.joinmastodon.org/2018/06/how-to-implement-a-basic-activitypub-server/
  31  * https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/
  32  *
  33  * Digest: https://tools.ietf.org/html/rfc5843
  34  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  35  *
  36  * To-do:
  37  *
  38  * Receiver:
  39  * - Activities: Follow, Accept, Update
  40  * - Object Types: Person, Tombstome
  41  *
  42  * Transmitter:
  43  * - Activities: Like, Dislike, Follow, Accept, Update
  44  * - Object Tyoes: Article, Announce, Person, Tombstone
  45  *
  46  * General:
  47  * - Message distribution
  48  * - Endpoints: Outbox, Object, Follower, Following
  49  */
  50 class ActivityPub
  51 {
  52         const PUBLIC = 'https://www.w3.org/ns/activitystreams#Public';
  53
  54         public static function transmit($data, $target, $uid)
  55         {
  56                 $owner = User::getOwnerDataById($uid);
  57
  58                 if (!$owner) {
  59                         return;
  60                 }
  61
  62                 $content = json_encode($data);
  63
  64                 $host = parse_url($target, PHP_URL_HOST);
  65                 $path = parse_url($target, PHP_URL_PATH);
  66                 $date = date('r');
  67
  68                 $headers = ['Host: ' . $host, 'Date: ' . $date];
  69
  70                 $signed_data = "(request-target): post " . $path . "\nhost: " . $host . "\ndate: " . $date;
  71
  72                 $signature = base64_encode(Crypto::rsaSign($signed_data, $owner['uprvkey'], 'sha256'));
  73
  74                 $headers[] = 'Signature: keyId="' . $owner['url'] . '#main-key' . '",headers="(request-target) host date",signature="' . $signature . '"';
  75                 $headers[] = 'Content-Type: application/activity+json';
  76
  77                 Network::post($target, $content, $headers);
  78                 $return_code = BaseObject::getApp()->get_curl_code();
  79
  80                 echo $return_code."\n";
  81         }
  82
  83         /**
  84          * Return the ActivityPub profile of the given user
  85          *
  86          * @param integer $uid User ID
  87          * @return array
  88          */
  89         public static function profile($uid)
  90         {
  91                 $accounttype = ['Person', 'Organization', 'Service', 'Group', 'Application'];
  92
  93                 $condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
  94                         'account_removed' => false, 'verified' => true];
  95                 $fields = ['guid', 'nickname', 'pubkey', 'account-type'];
  96                 $user = DBA::selectFirst('user', $fields, $condition);
  97                 if (!DBA::isResult($user)) {
  98                         return [];
  99                 }
 100
 101                 $fields = ['locality', 'region', 'country-name'];
 102                 $profile = DBA::selectFirst('profile', $fields, ['uid' => $uid, 'is-default' => true]);
 103                 if (!DBA::isResult($profile)) {
 104                         return [];
 105                 }
 106
 107                 $fields = ['name', 'url', 'location', 'about', 'avatar'];
 108                 $contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
 109                 if (!DBA::isResult($contact)) {
 110                         return [];
 111                 }
 112
 113                 $data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
 114                         ['uuid' => 'http://schema.org/identifier', 'sensitive' => 'as:sensitive',
 115                         'vcard' => 'http://www.w3.org/2006/vcard/ns#']]];
 116
 117                 $data['id'] = $contact['url'];
 118                 $data['uuid'] = $user['guid'];
 119                 $data['type'] = $accounttype[$user['account-type']];
 120                 $data['following'] = System::baseUrl() . '/following/' . $user['nickname'];
 121                 $data['followers'] = System::baseUrl() . '/followers/' . $user['nickname'];
 122                 $data['inbox'] = System::baseUrl() . '/inbox/' . $user['nickname'];
 123                 $data['outbox'] = System::baseUrl() . '/outbox/' . $user['nickname'];
 124                 $data['preferredUsername'] = $user['nickname'];
 125                 $data['name'] = $contact['name'];
 126                 $data['vcard:hasAddress'] = ['@type' => 'Home', 'vcard:country-name' => $profile['country-name'],
 127                         'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
 128                 $data['summary'] = $contact['about'];
 129                 $data['url'] = $contact['url'];
 130                 $data['manuallyApprovesFollowers'] = false;
 131                 $data['publicKey'] = ['id' => $contact['url'] . '#main-key',
 132                         'owner' => $contact['url'],
 133                         'publicKeyPem' => $user['pubkey']];
 134                 $data['endpoints'] = ['sharedInbox' => System::baseUrl() . '/inbox'];
 135                 $data['icon'] = ['type' => 'Image',
 136                         'url' => $contact['avatar']];
 137
 138                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
 139                 return $data;
 140         }
 141
 142         public static function createActivityFromItem($item_id)
 143         {
 144                 $item = Item::selectFirst([], ['id' => $item_id]);
 145
 146                 $data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
 147                         ['Emoji' => 'toot:Emoji', 'Hashtag' => 'as:Hashtag', 'atomUri' => 'ostatus:atomUri',
 148                         'conversation' => 'ostatus:conversation', 'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri',
 149                         'ostatus' => 'http://ostatus.org#', 'sensitive' => 'as:sensitive',
 150                         'toot' => 'http://joinmastodon.org/ns#']]];
 151
 152                 $data['type'] = 'Create';
 153                 $data['id'] = $item['uri'];
 154                 $data['actor'] = $item['author-link'];
 155                 $data['to'] = 'https://www.w3.org/ns/activitystreams#Public';
 156                 $data['object'] = self::createNote($item);
 157                 return $data;
 158         }
 159
 160         public static function createNote($item)
 161         {
 162                 $data = [];
 163                 $data['type'] = 'Note';
 164                 $data['id'] = $item['uri'];
 165
 166                 if ($item['uri'] != $item['thr-parent']) {
 167                         $data['inReplyTo'] = $item['thr-parent'];
 168                 }
 169
 170                 $conversation = DBA::selectFirst('conversation', ['conversation-uri'], ['item-uri' => $item['parent-uri']]);
 171                 if (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
 172                         $conversation_uri = $conversation['conversation-uri'];
 173                 } else {
 174                         $conversation_uri = $item['parent-uri'];
 175                 }
 176
 177                 $data['context'] = $data['conversation'] = $conversation_uri;
 178                 $data['actor'] = $item['author-link'];
 179                 $data['to'] = [];
 180                 if (!$item['private']) {
 181                         $data['to'][] = 'https://www.w3.org/ns/activitystreams#Public';
 182                 }
 183                 $data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
 184                 $data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
 185                 $data['attributedTo'] = $item['author-link'];
 186                 $data['name'] = BBCode::convert($item['title'], false, 7);
 187                 $data['content'] = BBCode::convert($item['body'], false, 7);
 188                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
 189                 //$data['summary'] = ''; // Ignore by now
 190                 //$data['sensitive'] = false; // - Query NSFW
 191                 //$data['emoji'] = []; // Ignore by now
 192                 //$data['tag'] = []; /// @ToDo
 193                 //$data['attachment'] = []; // @ToDo
 194                 return $data;
 195         }
 196
 197         public static function transmitActivity($activity, $target, $uid)
 198         {
 199                 $profile = Probe::uri($target, Protocol::ACTIVITYPUB);
 200
 201                 $owner = User::getOwnerDataById($uid);
 202
 203                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 204                         'id' => 'https://pirati.ca/activity/' . System::createGUID(),
 205                         'type' => $activity,
 206                         'actor' => $owner['url'],
 207                         'object' => $profile['url']];
 208
 209                 return self::transmit($data,  $profile['notify'], $uid);
 210         }
 211
 212         /**
 213          * Fetches ActivityPub content from the given url
 214          *
 215          * @param string $url content url
 216          * @return array
 217          */
 218         public static function fetchContent($url)
 219         {
 220                 $ret = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json']);
 221
 222                 if (!$ret['success'] || empty($ret['body'])) {
 223                         return;
 224                 }
 225
 226                 return json_decode($ret['body'], true);
 227         }
 228
 229         /**
 230          * Resolves the profile url from the address by using webfinger
 231          *
 232          * @param string $addr profile address (user@domain.tld)
 233          * @return string url
 234          */
 235         private static function addrToUrl($addr)
 236         {
 237                 $addr_parts = explode('@', $addr);
 238                 if (count($addr_parts) != 2) {
 239                         return false;
 240                 }
 241
 242                 $webfinger = 'https://' . $addr_parts[1] . '/.well-known/webfinger?resource=acct:' . urlencode($addr);
 243
 244                 $ret = Network::curl($webfinger, false, $redirects, ['accept_content' => 'application/jrd+json,application/json']);
 245                 if (!$ret['success'] || empty($ret['body'])) {
 246                         return false;
 247                 }
 248
 249                 $data = json_decode($ret['body'], true);
 250
 251                 if (empty($data['links'])) {
 252                         return false;
 253                 }
 254
 255                 foreach ($data['links'] as $link) {
 256                         if (empty($link['href']) || empty($link['rel']) || empty($link['type'])) {
 257                                 continue;
 258                         }
 259
 260                         if (($link['rel'] == 'self') && ($link['type'] == 'application/activity+json')) {
 261                                 return $link['href'];
 262                         }
 263                 }
 264
 265                 return false;
 266         }
 267
 268         public static function verifySignature($content, $http_headers)
 269         {
 270                 $object = json_decode($content, true);
 271
 272                 if (empty($object)) {
 273                         return false;
 274                 }
 275
 276                 $actor = self::processElement($object, 'actor', 'id');
 277
 278                 $headers = [];
 279                 $headers['(request-target)'] = strtolower($http_headers['REQUEST_METHOD']) . ' ' . $http_headers['REQUEST_URI'];
 280
 281                 // First take every header
 282                 foreach ($http_headers as $k => $v) {
 283                         $field = str_replace('_', '-', strtolower($k));
 284                         $headers[$field] = $v;
 285                 }
 286
 287                 // Now add every http header
 288                 foreach ($http_headers as $k => $v) {
 289                         if (strpos($k, 'HTTP_') === 0) {
 290                                 $field = str_replace('_', '-', strtolower(substr($k, 5)));
 291                                 $headers[$field] = $v;
 292                         }
 293                 }
 294
 295                 $sig_block = ActivityPub::parseSigHeader($http_headers['HTTP_SIGNATURE']);
 296
 297                 if (empty($sig_block) || empty($sig_block['headers']) || empty($sig_block['keyId'])) {
 298                         return false;
 299                 }
 300
 301                 $signed_data = '';
 302                 foreach ($sig_block['headers'] as $h) {
 303                         if (array_key_exists($h, $headers)) {
 304                                 $signed_data .= $h . ': ' . $headers[$h] . "\n";
 305                         }
 306                 }
 307                 $signed_data = rtrim($signed_data, "\n");
 308
 309                 if (empty($signed_data)) {
 310                         return false;
 311                 }
 312
 313                 $algorithm = null;
 314
 315                 if ($sig_block['algorithm'] === 'rsa-sha256') {
 316                         $algorithm = 'sha256';
 317                 }
 318
 319                 if ($sig_block['algorithm'] === 'rsa-sha512') {
 320                         $algorithm = 'sha512';
 321                 }
 322
 323                 if (empty($algorithm)) {
 324                         return false;
 325                 }
 326
 327                 $key = self::fetchKey($sig_block['keyId'], $actor);
 328
 329                 if (empty($key)) {
 330                         return false;
 331                 }
 332
 333                 if (!Crypto::rsaVerify($signed_data, $sig_block['signature'], $key, $algorithm)) {
 334                         return false;
 335                 }
 336
 337                 // Check the digest if it was part of the signed data
 338                 if (in_array('digest', $sig_block['headers'])) {
 339                         $digest = explode('=', $headers['digest'], 2);
 340                         if ($digest[0] === 'SHA-256') {
 341                                 $hashalg = 'sha256';
 342                         }
 343                         if ($digest[0] === 'SHA-512') {
 344                                 $hashalg = 'sha512';
 345                         }
 346
 347                         /// @todo add all hashes from the rfc
 348
 349                         if (!empty($hashalg) && base64_encode(hash($hashalg, $content, true)) != $digest[1]) {
 350                                 return false;
 351                         }
 352                 }
 353
 354                 // Check the content-length if it was part of the signed data
 355                 if (in_array('content-length', $sig_block['headers'])) {
 356                         if (strlen($content) != $headers['content-length']) {
 357                                 return false;
 358                         }
 359                 }
 360
 361                 return true;
 362
 363         }
 364
 365         private static function fetchKey($id, $actor)
 366         {
 367                 $url = (strpos($id, '#') ? substr($id, 0, strpos($id, '#')) : $id);
 368
 369                 $profile = Probe::uri($url, Protocol::ACTIVITYPUB);
 370                 if (!empty($profile)) {
 371                         return $profile['pubkey'];
 372                 } elseif ($url != $actor) {
 373                         $profile = Probe::uri($actor, Protocol::ACTIVITYPUB);
 374                         if (!empty($profile)) {
 375                                 return $profile['pubkey'];
 376                         }
 377                 }
 378
 379                 return false;
 380         }
 381
 382         /**
 383          * @brief
 384          *
 385          * @param string $header
 386          * @return array associate array with
 387          *   - \e string \b keyID
 388          *   - \e string \b algorithm
 389          *   - \e array  \b headers
 390          *   - \e string \b signature
 391          */
 392         private static function parseSigHeader($header)
 393         {
 394                 $ret = [];
 395                 $matches = [];
 396
 397                 if (preg_match('/keyId="(.*?)"/ism',$header,$matches)) {
 398                         $ret['keyId'] = $matches[1];
 399                 }
 400
 401                 if (preg_match('/algorithm="(.*?)"/ism',$header,$matches)) {
 402                         $ret['algorithm'] = $matches[1];
 403                 }
 404
 405                 if (preg_match('/headers="(.*?)"/ism',$header,$matches)) {
 406                         $ret['headers'] = explode(' ', $matches[1]);
 407                 }
 408
 409                 if (preg_match('/signature="(.*?)"/ism',$header,$matches)) {
 410                         $ret['signature'] = base64_decode(preg_replace('/\s+/','',$matches[1]));
 411                 }
 412
 413                 return $ret;
 414         }
 415
 416         /**
 417          * Fetches a profile from the given url
 418          *
 419          * @param string $url profile url
 420          * @return array
 421          */
 422         public static function fetchProfile($url)
 423         {
 424                 if (empty(parse_url($url, PHP_URL_SCHEME))) {
 425                         $url = self::addrToUrl($url);
 426                         if (empty($url)) {
 427                                 return false;
 428                         }
 429                 }
 430
 431                 $data = self::fetchContent($url);
 432
 433                 if (empty($data) || empty($data['id']) || empty($data['inbox'])) {
 434                         return false;
 435                 }
 436
 437                 $profile = ['network' => Protocol::ACTIVITYPUB];
 438                 $profile['nick'] = $data['preferredUsername'];
 439                 $profile['name'] = defaults($data, 'name', $profile['nick']);
 440                 $profile['guid'] = defaults($data, 'uuid', null);
 441                 $profile['url'] = $data['id'];
 442
 443                 $parts = parse_url($profile['url']);
 444                 unset($parts['scheme']);
 445                 unset($parts['path']);
 446                 $profile['addr'] = $profile['nick'] . '@' . str_replace('//', '', Network::unparseURL($parts));
 447                 $profile['alias'] = self::processElement($data, 'url', 'href');
 448                 $profile['photo'] = self::processElement($data, 'icon', 'url');
 449                 // $profile['community']
 450                 // $profile['keywords']
 451                 // $profile['location']
 452                 $profile['about'] = defaults($data, 'summary', '');
 453                 $profile['batch'] = self::processElement($data, 'endpoints', 'sharedInbox');
 454                 $profile['notify'] = $data['inbox'];
 455                 $profile['poll'] = $data['outbox'];
 456                 $profile['pubkey'] = self::processElement($data, 'publicKey', 'publicKeyPem');
 457
 458                 // Check if the address is resolvable
 459                 if (self::addrToUrl($profile['addr']) == $profile['url']) {
 460                         $parts = parse_url($profile['url']);
 461                         unset($parts['path']);
 462                         $profile['baseurl'] = Network::unparseURL($parts);
 463                 } else {
 464                         unset($profile['addr']);
 465                 }
 466
 467                 if ($profile['url'] == $profile['alias']) {
 468                         unset($profile['alias']);
 469                 }
 470
 471                 // Remove all "null" fields
 472                 foreach ($profile as $field => $content) {
 473                         if (is_null($content)) {
 474                                 unset($profile[$field]);
 475                         }
 476                 }
 477
 478 /*
 479                 // To-Do
 480                 unset($data['type']);
 481                 unset($data['manuallyApprovesFollowers']);
 482
 483                 // Unhandled
 484                 unset($data['@context']);
 485                 unset($data['tag']);
 486                 unset($data['attachment']);
 487                 unset($data['image']);
 488                 unset($data['nomadicLocations']);
 489                 unset($data['signature']);
 490                 unset($data['following']);
 491                 unset($data['followers']);
 492                 unset($data['featured']);
 493                 unset($data['movedTo']);
 494                 unset($data['liked']);
 495                 unset($data['sharedInbox']); // Misskey
 496                 unset($data['isCat']); // Misskey
 497                 unset($data['kroeg:blocks']); // Kroeg
 498                 unset($data['updated']); // Kroeg
 499 */
 500                 return $profile;
 501         }
 502
 503         public static function processInbox($body, $header, $uid)
 504         {
 505                 logger('Incoming message for user ' . $uid, LOGGER_DEBUG);
 506
 507                 if (!self::verifySignature($body, $header)) {
 508                         logger('Invalid signature, message will be discarded.', LOGGER_DEBUG);
 509                         return;
 510                 }
 511
 512                 $activity = json_decode($body, true);
 513
 514                 if (!is_array($activity)) {
 515                         logger('Invalid body.', LOGGER_DEBUG);
 516                         return;
 517                 }
 518
 519                 self::processActivity($activity, $body, $uid);
 520         }
 521
 522         public static function fetchOutbox($url)
 523         {
 524                 $data = self::fetchContent($url);
 525                 if (empty($data)) {
 526                         return;
 527                 }
 528
 529                 if (!empty($data['orderedItems'])) {
 530                         $items = $data['orderedItems'];
 531                 } elseif (!empty($data['first']['orderedItems'])) {
 532                         $items = $data['first']['orderedItems'];
 533                 } elseif (!empty($data['first'])) {
 534                         self::fetchOutbox($data['first']);
 535                         return;
 536                 } else {
 537                         $items = [];
 538                 }
 539
 540                 foreach ($items as $activity) {
 541                         self::processActivity($activity);
 542                 }
 543         }
 544
 545         function processActivity($activity, $body = '', $uid = null)
 546         {
 547                 if (empty($activity['type'])) {
 548                         logger('Empty type', LOGGER_DEBUG);
 549                         return;
 550                 }
 551
 552                 if (empty($activity['object'])) {
 553                         logger('Empty object', LOGGER_DEBUG);
 554                         return;
 555                 }
 556
 557                 if (empty($activity['actor'])) {
 558                         logger('Empty actor', LOGGER_DEBUG);
 559                         return;
 560
 561                 }
 562
 563                 $actor = self::processElement($activity, 'actor', 'id');
 564                 if (empty($actor)) {
 565                         logger('Empty actor - 2', LOGGER_DEBUG);
 566                         return;
 567                 }
 568
 569                 if (is_string($activity['object'])) {
 570                         $object_url = $activity['object'];
 571                 } elseif (!empty($activity['object']['id'])) {
 572                         $object_url = $activity['object']['id'];
 573                 } else {
 574                         logger('No object found', LOGGER_DEBUG);
 575                         return;
 576                 }
 577
 578                 // ----------------------------------
 579 /*
 580                 // unhandled
 581                 unset($activity['@context']);
 582                 unset($activity['id']);
 583
 584                 // Non standard
 585                 unset($activity['title']);
 586                 unset($activity['atomUri']);
 587                 unset($activity['context_id']);
 588                 unset($activity['statusnetConversationId']);
 589
 590                 // To-Do?
 591                 unset($activity['context']);
 592                 unset($activity['location']);
 593                 unset($activity['signature']);
 594 */
 595                 // Fetch all receivers from to, cc, bto and bcc
 596                 $receivers = self::getReceivers($activity);
 597
 598                 // When it is a delivery to a personal inbox we add that user to the receivers
 599                 if (!empty($uid)) {
 600                         $owner = User::getOwnerDataById($uid);
 601                         $additional = [$owner['url'] => $uid];
 602                         $receivers = array_merge($receivers, $additional);
 603                 }
 604
 605                 logger('Receivers: ' . json_encode($receivers), LOGGER_DEBUG);
 606
 607                 if (!in_array($activity['type'], ['Like', 'Dislike'])) {
 608                         $item = self::fetchObject($object_url, $activity['object']);
 609                         if (empty($item)) {
 610                                 logger("Object data couldn't be processed", LOGGER_DEBUG);
 611                                 return;
 612                         }
 613                 } else {
 614                         $item['object'] = $object_url;
 615                         $item['receiver'] = [];
 616                         $item['type'] = $activity['type'];
 617                 }
 618
 619                 $item = self::addActivityFields($item, $activity);
 620
 621                 $item['owner'] = $actor;
 622
 623                 $item['receiver'] = array_merge($item['receiver'], $receivers);
 624
 625                 logger('Processing activity: ' . $activity['type'], LOGGER_DEBUG);
 626
 627                 switch ($activity['type']) {
 628                         case 'Create':
 629                         case 'Update':
 630                         case 'Announce':
 631                                 self::createItem($item, $body);
 632                                 break;
 633
 634                         case 'Like':
 635                         case 'Dislike':
 636                                 self::activityItem($item, $body);
 637                                 break;
 638
 639                         case 'Follow':
 640                                 break;
 641
 642                         default:
 643                                 logger('Unknown activity: ' . $activity['type'], LOGGER_DEBUG);
 644                                 break;
 645                 }
 646         }
 647
 648         private static function getReceivers($activity)
 649         {
 650                 $receivers = [];
 651
 652                 $elements = ['to', 'cc', 'bto', 'bcc'];
 653                 foreach ($elements as $element) {
 654                         if (empty($activity[$element])) {
 655                                 continue;
 656                         }
 657
 658                         // The receiver can be an arror or a string
 659                         if (is_string($activity[$element])) {
 660                                 $activity[$element] = [$activity[$element]];
 661                         }
 662
 663                         foreach ($activity[$element] as $receiver) {
 664                                 if ($receiver == self::PUBLIC) {
 665                                         $receivers[$receiver] = 0;
 666                                 }
 667
 668                                 $condition = ['self' => true, 'nurl' => normalise_link($receiver)];
 669                                 $contact = DBA::selectFirst('contact', ['uid'], $condition);
 670                                 if (!DBA::isResult($contact)) {
 671                                         continue;
 672                                 }
 673                                 $receivers[$receiver] = $contact['uid'];
 674                         }
 675                 }
 676                 return $receivers;
 677         }
 678
 679         private static function addActivityFields($item, $activity)
 680         {
 681                 if (!empty($activity['published']) && empty($item['published'])) {
 682                         $item['published'] = $activity['published'];
 683                 }
 684
 685                 if (!empty($activity['updated']) && empty($item['updated'])) {
 686                         $item['updated'] = $activity['updated'];
 687                 }
 688
 689                 if (!empty($activity['inReplyTo']) && empty($item['parent-uri'])) {
 690                         $item['parent-uri'] = self::processElement($activity, 'inReplyTo', 'id');
 691                 }
 692
 693                 if (!empty($activity['instrument'])) {
 694                         $item['service'] = self::processElement($activity, 'instrument', 'name', 'type', 'Service');
 695                 }
 696                 return $item;
 697         }
 698
 699         private static function fetchObject($object_url, $object = [])
 700         {
 701                 $data = self::fetchContent($object_url);
 702                 if (empty($data)) {
 703                         $data = $object;
 704                         if (empty($data)) {
 705                                 logger('Empty content', LOGGER_DEBUG);
 706                                 return false;
 707                         } elseif (is_string($data)) {
 708                                 logger('No object array provided.', LOGGER_DEBUG);
 709                                 $item = Item::selectFirst([], ['uri' => $data]);
 710                                 if (!DBA::isResult($item)) {
 711                                         logger('Object with url ' . $data . ' was not found locally.', LOGGER_DEBUG);
 712                                         return false;
 713                                 }
 714                                 logger('Using already stored item', LOGGER_DEBUG);
 715                                 $data = self::createNote($item);
 716                         } else {
 717                                 logger('Using provided object', LOGGER_DEBUG);
 718                         }
 719                 }
 720
 721                 if (empty($data['type'])) {
 722                         logger('Empty type', LOGGER_DEBUG);
 723                         return false;
 724                 } else {
 725                         $type = $data['type'];
 726                         logger('Type ' . $type, LOGGER_DEBUG);
 727                 }
 728
 729                 if (in_array($type, ['Note', 'Article', 'Video'])) {
 730                         $common = self::processCommonData($data);
 731                 }
 732
 733                 switch ($type) {
 734                         case 'Note':
 735                                 return array_merge($common, self::processNote($data));
 736                         case 'Article':
 737                                 return array_merge($common, self::processArticle($data));
 738                         case 'Video':
 739                                 return array_merge($common, self::processVideo($data));
 740
 741                         case 'Announce':
 742                                 if (empty($data['object'])) {
 743                                         return false;
 744                                 }
 745                                 return self::fetchObject($data['object']);
 746
 747                         case 'Person':
 748                         case 'Tombstone':
 749                                 break;
 750
 751                         default:
 752                                 logger('Unknown object type: ' . $data['type'], LOGGER_DEBUG);
 753                                 break;
 754                 }
 755         }
 756
 757         private static function processCommonData(&$object)
 758         {
 759                 if (empty($object['id']) || empty($object['attributedTo'])) {
 760                         return false;
 761                 }
 762
 763                 $item = [];
 764                 $item['type'] = $object['type'];
 765                 $item['uri'] = $object['id'];
 766
 767                 if (!empty($object['inReplyTo'])) {
 768                         $item['reply-to-uri'] = self::processElement($object, 'inReplyTo', 'id');
 769                 } else {
 770                         $item['reply-to-uri'] = $item['uri'];
 771                 }
 772
 773                 $item['published'] = defaults($object, 'published', null);
 774                 $item['updated'] = defaults($object, 'updated', $item['published']);
 775
 776                 if (empty($item['published']) && !empty($item['updated'])) {
 777                         $item['published'] = $item['updated'];
 778                 }
 779
 780                 $item['uuid'] = defaults($object, 'uuid', null);
 781                 $item['owner'] = $item['author'] = self::processElement($object, 'attributedTo', 'id');
 782                 $item['context'] = defaults($object, 'context', null);
 783                 $item['conversation'] = defaults($object, 'conversation', null);
 784                 $item['sensitive'] = defaults($object, 'sensitive', null);
 785                 $item['name'] = defaults($object, 'title', null);
 786                 $item['name'] = defaults($object, 'name', $item['name']);
 787                 $item['summary'] = defaults($object, 'summary', null);
 788                 $item['content'] = defaults($object, 'content', null);
 789                 $item['source'] = defaults($object, 'source', null);
 790                 $item['location'] = self::processElement($object, 'location', 'name', 'type', 'Place');
 791                 $item['attachments'] = defaults($object, 'attachment', null);
 792                 $item['tags'] = defaults($object, 'tag', null);
 793                 $item['service'] = self::processElement($object, 'instrument', 'name', 'type', 'Service');
 794                 $item['alternate-url'] = self::processElement($object, 'url', 'href');
 795                 $item['receiver'] = self::getReceivers($object);
 796
 797 /*
 798                 // To-Do
 799                 unset($object['source']);
 800
 801                 // Unhandled
 802                 unset($object['@context']);
 803                 unset($object['type']);
 804                 unset($object['actor']);
 805                 unset($object['signature']);
 806                 unset($object['mediaType']);
 807                 unset($object['duration']);
 808                 unset($object['replies']);
 809                 unset($object['icon']);
 810
 811                 // Also missing:
 812                 audience, preview, endTime, startTime, generator, image
 813 */
 814                 return $item;
 815         }
 816
 817         private static function processNote($object)
 818         {
 819                 $item = [];
 820
 821 /*
 822                 // To-Do?
 823                 unset($object['emoji']);
 824                 unset($object['atomUri']);
 825                 unset($object['inReplyToAtomUri']);
 826
 827                 // Unhandled
 828                 unset($object['contentMap']);
 829                 unset($object['announcement_count']);
 830                 unset($object['announcements']);
 831                 unset($object['context_id']);
 832                 unset($object['likes']);
 833                 unset($object['like_count']);
 834                 unset($object['inReplyToStatusId']);
 835                 unset($object['shares']);
 836                 unset($object['quoteUrl']);
 837                 unset($object['statusnetConversationId']);
 838 */
 839                 return $item;
 840         }
 841
 842         private static function processArticle($object)
 843         {
 844                 $item = [];
 845
 846                 return $item;
 847         }
 848
 849         private static function processVideo($object)
 850         {
 851                 $item = [];
 852 /*
 853                 // To-Do?
 854                 unset($object['category']);
 855                 unset($object['licence']);
 856                 unset($object['language']);
 857                 unset($object['commentsEnabled']);
 858
 859                 // Unhandled
 860                 unset($object['views']);
 861                 unset($object['waitTranscoding']);
 862                 unset($object['state']);
 863                 unset($object['support']);
 864                 unset($object['subtitleLanguage']);
 865                 unset($object['likes']);
 866                 unset($object['dislikes']);
 867                 unset($object['shares']);
 868                 unset($object['comments']);
 869 */
 870                 return $item;
 871         }
 872
 873         private static function processElement($array, $element, $key, $type = null, $type_value = null)
 874         {
 875                 if (empty($array)) {
 876                         return false;
 877                 }
 878
 879                 if (empty($array[$element])) {
 880                         return false;
 881                 }
 882
 883                 if (is_string($array[$element])) {
 884                         return $array[$element];
 885                 }
 886
 887                 if (is_null($type_value)) {
 888                         if (!empty($array[$element][$key])) {
 889                                 return $array[$element][$key];
 890                         }
 891
 892                         if (!empty($array[$element][0][$key])) {
 893                                 return $array[$element][0][$key];
 894                         }
 895
 896                         return false;
 897                 }
 898
 899                 if (!empty($array[$element][$key]) && !empty($array[$element][$type]) && ($array[$element][$type] == $type_value)) {
 900                         return $array[$element][$key];
 901                 }
 902
 903                 /// @todo Add array search
 904
 905                 return false;
 906         }
 907
 908         private static function convertMentions($body)
 909         {
 910                 $URLSearchString = "^\[\]";
 911                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
 912
 913                 return $body;
 914         }
 915
 916         private static function constructTagList($tags, $sensitive)
 917         {
 918                 if (empty($tags)) {
 919                         return '';
 920                 }
 921
 922                 $tag_text = '';
 923                 foreach ($tags as $tag) {
 924                         if (in_array($tag['type'], ['Mention', 'Hashtag'])) {
 925                                 if (!empty($tag_text)) {
 926                                         $tag_text .= ',';
 927                                 }
 928
 929                                 $tag_text .= substr($tag['name'], 0, 1) . '[url=' . $tag['href'] . ']' . substr($tag['name'], 1) . '[/url]';
 930                         }
 931                 }
 932
 933                 /// @todo add nsfw for $sensitive
 934
 935                 return $tag_text;
 936         }
 937
 938         private static function constructAttachList($attachments, $item)
 939         {
 940                 if (empty($attachments)) {
 941                         return $item;
 942                 }
 943
 944                 foreach ($attachments as $attach) {
 945                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 946                         if ($filetype == 'image') {
 947                                 $item['body'] .= "\n[img]".$attach['url'].'[/img]';
 948                         } else {
 949                                 if (!empty($item["attach"])) {
 950                                         $item["attach"] .= ',';
 951                                 } else {
 952                                         $item["attach"] = '';
 953                                 }
 954                                 if (!isset($attach['length'])) {
 955                                         $attach['length'] = "0";
 956                                 }
 957                                 $item["attach"] .= '[attach]href="'.$attach['url'].'" length="'.$attach['length'].'" type="'.$attach['mediaType'].'" title="'.defaults($attach, 'name', '').'"[/attach]';
 958                         }
 959                 }
 960
 961                 return $item;
 962         }
 963
 964         private static function createItem($activity, $body)
 965         {
 966                 /// @todo What to do with $activity['context']?
 967
 968                 $item = [];
 969                 $item['network'] = Protocol::ACTIVITYPUB;
 970                 $item['private'] = !in_array(0, $activity['receiver']);
 971                 $item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
 972                 $item['owner-id'] = Contact::getIdForURL($activity['owner'], 0, true);
 973                 $item['uri'] = $activity['uri'];
 974                 $item['parent-uri'] = $activity['reply-to-uri'];
 975                 $item['verb'] = ACTIVITY_POST;
 976                 $item['object-type'] = ACTIVITY_OBJ_NOTE; /// Todo?
 977                 $item['created'] = $activity['published'];
 978                 $item['edited'] = $activity['updated'];
 979                 $item['guid'] = $activity['uuid'];
 980                 $item['title'] = HTML::toBBCode($activity['name']);
 981                 $item['content-warning'] = HTML::toBBCode($activity['summary']);
 982                 $item['body'] = self::convertMentions(HTML::toBBCode($activity['content']));
 983                 $item['location'] = $activity['location'];
 984                 $item['tag'] = self::constructTagList($activity['tags'], $activity['sensitive']);
 985                 $item['app'] = $activity['service'];
 986                 $item['plink'] = defaults($activity, 'alternate-url', $item['uri']);
 987
 988                 $item = self::constructAttachList($activity['attachments'], $item);
 989
 990                 $source = self::processElement($activity, 'source', 'content', 'mediaType', 'text/bbcode');
 991                 if (!empty($source)) {
 992                         $item['body'] = $source;
 993                 }
 994
 995                 $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 996                 $item['source'] = $body;
 997                 $item['conversation-uri'] = $activity['conversation'];
 998
 999                 foreach ($activity['receiver'] as $receiver) {
1000                         $item['uid'] = $receiver;
1001                         $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
1002
1003                         if (($receiver != 0) && empty($item['contact-id'])) {
1004                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
1005                         }
1006
1007                         $item_id = Item::insert($item);
1008                         logger('Storing for user ' . $item['uid'] . ': ' . $item_id);
1009                         if (!empty($item_id) && ($item['uid'] == 0)) {
1010                                 Item::distribute($item_id);
1011                         }
1012                 }
1013         }
1014
1015         private static function activityItem($data)
1016         {
1017                 logger('Activity "' . $data['type'] . '" for ' . $data['object']);
1018                 $items = Item::select(['id'], ['uri' => $data['object']]);
1019                 while ($item = Item::fetch($items)) {
1020                         logger('Activity ' . $data['type'] . ' for item ' . $item['id'], LOGGER_DEBUG);
1021                         Item::performLike($item['id'], strtolower($data['type']));
1022                 }
1023                 DBA::close($item);
1024                 logger('Activity done', LOGGER_DEBUG);
1025         }
1026
1027 }