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