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