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