/**
  * Processes a session request from the client
  * @param $action Command that is to be performed
  * @param $auth Auth interface to identify the current user
  * @param $args Arguments for the given command
  * @return stdClass Object that is supposed to be sent back to the client
  */
 function process($action, $auth, $args)
 {
     global $mediabirdDb;
     $dataHandler = new MediabirdDataHandler($auth->userId);
     $reply = (object) null;
     if (isset($args['settings'])) {
         $settings = MediabirdUtility::getArgNoSlashes($args['settings']);
         $dataHandler->storeSettings($settings);
     }
     switch ($action) {
         case "keepAlive":
             //keep alive session, that's done above
             $reply->success = true;
             break;
         case "loadTopicList":
             //retrieve the topic list
             $query = "SELECT id FROM " . MediabirdConfig::tableName('Topic') . " WHERE user_id='{$auth->userId}'";
             $infos = (array) null;
             if ($result = $mediabirdDb->getRecordSet($query)) {
                 while ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result))) {
                     $id = intval($results['id']);
                     $infos[$id] = MediabirdTopicAccessConstants::owner;
                 }
                 $query = "SELECT topic,mask FROM " . MediabirdConfig::tableName('Right') . " WHERE mask>0 AND group_id=ANY (SELECT group_id FROM " . MediabirdConfig::tableName('Membership') . " WHERE user_id={$auth->userId} AND active=1)";
                 if ($result = $mediabirdDb->getRecordSet($query)) {
                     $reply->topics = (array) null;
                     while ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result))) {
                         $id = intval($results['topic']);
                         $mask = intval($results['mask']);
                         if (array_key_exists($id, $infos)) {
                             $infos[$id] = $infos[$id] | $mask;
                         } else {
                             $infos[$id] = $mask;
                         }
                     }
                     $reply->topics = (array) null;
                     foreach ($infos as $id => $mask) {
                         if ($topic = $dataHandler->updateTopic($id, null, $mask, true)) {
                             $topic->access = $mask;
                             $reply->topics[] = $topic;
                         }
                     }
                 } else {
                     $reply->error = "database error";
                     error_log($query);
                 }
             } else {
                 $reply->error = "database error";
                 error_log($query);
             }
             $reply->success = true;
             break;
         case "checkTopicRevision":
             $remoteRevision = intval($args['revision']);
             // revision on client
             $topicId = intval($args['id']);
             if ($topic = $mediabirdDb->getRecord(MediabirdConfig::tableName('Topic', true), "id={$topicId}")) {
                 //attempt to load topic as owner
                 if ($topic->user_id != $auth->userId) {
                     if ($dataHandler->getTopicRights($topicId) < MediabirdTopicAccessConstants::allowViewingCards) {
                         $reply->error = "accessdenied";
                         break;
                     }
                 }
                 $revision = intval($topic->revision);
                 // revision in db
                 if ($revision <= $remoteRevision) {
                     $reply->success = true;
                     //revision is up-to-date
                     break;
                 } else {
                     //fall through
                     $data = null;
                     $ignoreContent = true;
                 }
             } else {
                 $reply->error = "database error";
                 break;
             }
             //fall through
         //fall through
         case "updateTopic":
             //update or create a topic
             if ($action == "updateTopic") {
                 $data = json_decode(MediabirdUtility::getArgNoSlashes($args['topic']));
                 if (isset($args['id']) && is_numeric($args['id'])) {
                     $topicId = intval(MediabirdUtility::getArgNoSlashes($args['id']));
                     $ignoreContent = true;
                 } else {
                     if (property_exists($data, "title") && property_exists($data, "category") && strlen($data->title) > 0 && strlen($data->category) > 0) {
                         $topic = (object) null;
                         $topic->user_id = $auth->userId;
                         $topic->created = $mediabirdDb->datetime(time());
                         $topic->modified = $mediabirdDb->datetime(time());
                         $topic->title = '-';
                         if ($topicId = $mediabirdDb->insertRecord(MediabirdConfig::tableName('Topic', true), $topic)) {
                             $ignoreContent = false;
                             //update content for new topic
                         } else {
                             $reply->error = "database error";
                         }
                     } else {
                         $reply->error = "invaliddata";
                     }
                 }
             }
             if (!isset($reply->error)) {
                 //check if user is owner
                 $query = "SELECT user_id FROM " . MediabirdConfig::tableName('Topic') . " WHERE id={$topicId}";
                 if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1) {
                     $results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result));
                     $owner = intval($results['user_id']);
                     $mask = 0;
                     if ($owner != $auth->userId) {
                         //retrieve access rights
                         $mask = $dataHandler->getTopicRights($topicId);
                     } else {
                         //owner has full rights
                         $mask = MediabirdTopicAccessConstants::owner;
                     }
                     if ($mask == 0) {
                         $reply->error = "accessdenied";
                     }
                 } else {
                     $reply->error = "database error";
                 }
             }
             if (!isset($reply->error)) {
                 if ($topic = $dataHandler->updateTopic($topicId, $data, $mask, $ignoreContent)) {
                     $topic->access = $mask;
                     $reply->success = true;
                     if (isset($topic->reverted)) {
                         $reply->reverted = $topic->reverted;
                         unset($topic->reverted);
                     }
                     $reply->topic = $topic;
                 } else {
                     $reply->error = "database error";
                 }
             }
             break;
         case "updateTopicLicense":
             //update or create a topic
             $topicId = intval(MediabirdUtility::getArgNoSlashes($args['id']));
             $newLicense = intval(MediabirdUtility::getArgNoSlashes($args['license']));
             $query = "SELECT license,user_id FROM " . MediabirdConfig::tableName('Topic') . " WHERE id={$topicId}";
             if (($result = $mediabirdDb->getRecordSet($query)) && ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result)))) {
                 $license = intval($results['license']);
                 $user = intval($results['user_id']);
                 if ($user == $auth->userId) {
                     if ($license != $newLicense) {
                         $topicDb = (object) null;
                         $topicDb->id = $topicId;
                         $topicDb->license = $newLicense;
                         if ($mediabirdDb->updateRecord(MediabirdConfig::tableName('Topic', true), $topicDb)) {
                             $reply->success = true;
                             $reply->license = $newLicense;
                         } else {
                             $reply->error = "database error";
                         }
                     } else {
                         $reply->success = true;
                         $reply->license = $license;
                     }
                 } else {
                     $reply->error = "accessdenied";
                 }
             } else {
                 $reply->error = "database error";
             }
             break;
         case "deleteTopics":
             //delete a topic
             $topicIds = split(",", $args['ids']);
             foreach ($topicIds as $topicId) {
                 //get user of topic and check if current user is owner
                 $query = "SELECT user_id FROM " . MediabirdConfig::tableName('Topic') . " WHERE id={$topicId} AND user_id={$auth->userId}";
                 if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1) {
                     if ($dataHandler->deleteTopic($topicId)) {
                         $reply->success = true;
                     } else {
                         unset($reply->success);
                         $reply->error = "database error";
                         break;
                     }
                 } else {
                     unset($reply->success);
                     $reply->error = "accessdenied";
                     break;
                 }
             }
             break;
         case "updateCard":
             //updates the contents and markers of an already registered content card
             $isUpdateCard = true;
         case "updateMarkers":
             //updates the personal markers of an already registered content card
             $cardId = intval($args['id']);
             if (!isset($isUpdateCard)) {
                 $isUpdateCard = false;
             }
             //determine topic
             $query = "SELECT id,user_id FROM " . MediabirdConfig::tableName('Topic') . " WHERE id=ANY (SELECT topic FROM " . MediabirdConfig::tableName('Card') . " WHERE id={$cardId})";
             if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1) {
                 $record = $mediabirdDb->fetchNextRecord($result);
                 $topicId = intval($record->id);
                 $owner = intval($record->user_id);
                 $mask = 0;
                 if ($owner != $auth->userId) {
                     $mask = $dataHandler->getTopicRights($topicId);
                 } else {
                     $mask = MediabirdTopicAccessConstants::owner;
                 }
                 if ($mask == 0) {
                     $reply->error = "accessdenied";
                 }
             } else {
                 error_log($query);
                 $reply->error = "accessdenied";
             }
             if (isset($args["markers"])) {
                 $markers = json_decode(MediabirdUtility::getArgNoSlashes($args["markers"]));
             }
             $deletedMarkerIds = array();
             //default to "none deleted"
             if (isset($args["deletedMarkerIds"])) {
                 $deletedMarkerIds = json_decode(MediabirdUtility::getArgNoSlashes($args["deletedMarkerIds"]));
             }
             if ($isUpdateCard) {
                 //check for card locks
                 $minuteAgo = $mediabirdDb->datetime(time() - 60);
                 $query = "SELECT id FROM " . MediabirdConfig::tableName('Card') . " WHERE id={$cardId} AND (locked_by={$auth->userId} OR locked_by=0 OR locked_time < '{$minuteAgo}')";
                 if ($result = $mediabirdDb->getRecordSet($query)) {
                     if ($mediabirdDb->recordLength($result) == 1) {
                         $properties = (object) null;
                         if (isset($args["content"])) {
                             if ($args["content"] == "null") {
                                 $properties->content = null;
                             } else {
                                 $content = $dataHandler->purifyHTML(MediabirdUtility::getArgNoSlashes($args["content"]));
                                 if (strlen($content) > MediabirdConstants::maxCardSize) {
                                     $reply->error = "toobig";
                                 } else {
                                     $properties->content = $content;
                                 }
                             }
                         }
                         if (isset($args["title"])) {
                             $properties->title = MediabirdUtility::getArgNoSlashes($args["title"]);
                         }
                         if (isset($markers)) {
                             $properties->markers = $markers;
                         }
                     } else {
                         $reply->error = "locked";
                     }
                 } else {
                     error_log($query);
                     $reply->error = "database error";
                 }
             } else {
                 $properties = $markers;
             }
             if (!isset($reply->error)) {
                 if ($isUpdateCard) {
                     if ($card = $dataHandler->updateCard($topicId, $cardId, $properties, $mask, null, property_exists($properties, "markers"))) {
                         if (!property_exists($properties, "markers") || is_array($card->markers = $dataHandler->updateMarkers($cardId, $properties->markers, $deletedMarkerIds, $mask, $auth->userId))) {
                             $reply->success = true;
                             $reply->content = $card->content;
                             $reply->revision = $card->revision;
                             $reply->title = $card->title;
                             if (property_exists($card, "markers") && is_array($card->markers)) {
                                 $reply->markers = $card->markers;
                             }
                         } else {
                             $reply->error = "database error";
                         }
                     } else {
                         $reply->error = "database error";
                     }
                 } else {
                     if (($markers = $dataHandler->updateMarkers($cardId, $properties, $deletedMarkerIds, $mask, $auth->userId)) !== null) {
                         $reply->success = true;
                         $reply->markers = $markers;
                         $query = "SELECT revision FROM " . MediabirdConfig::tableName('Card') . " WHERE id={$cardId}";
                         if ($result = $mediabirdDb->getRecordSet($query)) {
                             $results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result));
                             $revision = intval($results['revision']);
                             $revision++;
                             $card = (object) null;
                             $card->id = $cardId;
                             $card->revision = $revision;
                             if (!$mediabirdDb->updateRecord(MediabirdConfig::tableName('Card', true), $card)) {
                                 error_log("could not increase revision of card {$cardId}");
                             }
                         } else {
                             error_log($query);
                         }
                     } else {
                         $reply->error = "database error";
                     }
                 }
             }
             break;
         case "checkCardRevision":
             $id = intval($args['id']);
             $rev = intval($args['revision']);
             if ($card = $mediabirdDb->getRecord(MediabirdConfig::tableName('Card', true), "id={$id}")) {
                 $topicId = $card->topic;
                 if ($topic = $mediabirdDb->getRecord(MediabirdConfig::tableName('Topic', true), "id={$topicId}")) {
                     //attempt to load topic as owner
                     if ($topic->user_id != $auth->userId) {
                         if ($dataHandler->getTopicRights($topicId) < MediabirdTopicAccessConstants::allowViewingCards) {
                             $reply->error = "accessdenied";
                             break;
                         }
                     }
                     //access okay
                     $revision = intval($card->revision);
                     if ($revision <= $rev) {
                         $reply->success = true;
                         break;
                     } else {
                         $args['ids'] = "{$id}";
                         //fall through to "loadCards"
                     }
                 } else {
                     $reply->error = "database error";
                     break;
                 }
             } else {
                 $reply->error = "database error";
                 break;
             }
             //fall through
         //fall through
         case "loadCards":
             //retrieves the contents of content cards (given by their id)
             $cardIds = explode(",", MediabirdUtility::getArgNoSlashes($args['ids']));
             $cards = (array) null;
             foreach ($cardIds as $cardId) {
                 //determine topic
                 $query = "SELECT id,user_id FROM " . MediabirdConfig::tableName('Topic') . " WHERE id=ANY (SELECT topic FROM " . MediabirdConfig::tableName('Card') . " WHERE id={$cardId})";
                 if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1) {
                     $results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result));
                     $topicId = intval($results['id']);
                     $owner = intval($results['user_id']);
                     $mask = 0;
                     if ($owner != $auth->userId) {
                         $mask = $dataHandler->getTopicRights($topicId);
                     } else {
                         $mask = MediabirdTopicAccessConstants::owner;
                     }
                     if ($mask == 0) {
                         $reply->error = "accessdenied";
                     }
                 } else {
                     $reply->error = "accessdenied";
                 }
                 //load content
                 if ($card = $dataHandler->updateCard($topicId, $cardId, null, $mask)) {
                     if (is_array($markers = $dataHandler->updateMarkers($cardId, null, array(), $mask, $auth->userId))) {
                         $card->markers = $markers;
                         foreach ($card->markers as $marker) {
                             //load flash cards
                             $query = "SELECT * FROM " . MediabirdConfig::tableName('Flashcard') . " WHERE marker={$marker->id} AND user_id={$auth->userId} ORDER BY num ASC";
                             $resultFlashCards = $mediabirdDb->getRecordSet($query);
                             while ($resultsFlashCards = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($resultFlashCards))) {
                                 $flashCard = (object) null;
                                 $flashCard->marker = $marker->id;
                                 $flashCard->number = intval($resultsFlashCards['num']);
                                 $flashCard->level = intval($resultsFlashCards['level_num']);
                                 if (isset($resultsFlashCards['markedforrepetition'])) {
                                     $flashCard->markedForRepetition = intval($resultsFlashCards['markedforrepetition']);
                                 } else {
                                     $flashCard->markedForRepetition = 0;
                                 }
                                 if (isset($resultsFlashCards['lasttimeanswered'])) {
                                     $flashCard->lastTimeAnswered = intval($resultsFlashCards['lasttimeanswered']);
                                 } else {
                                     $flashCard->lastTimeAnswered = 0;
                                 }
                                 $trainingData = intval($resultsFlashCards['results']);
                                 for ($i = 0; $i < 5; $i++) {
                                     $flashCard->results[] = ($trainingData & 3 * pow(4, $i)) / pow(4, $i);
                                 }
                                 $marker->flashCards[] = $flashCard;
                             }
                         }
                         $cards[] = $card;
                     } else {
                         $reply->error = "database error";
                     }
                 } else {
                     $reply->error = "database error";
                 }
             }
             if (!isset($reply->error)) {
                 $reply->success = true;
                 $reply->cards = $cards;
             }
             break;
         case "updateTrainingSession":
             //stores the current training session, expects a marker=>flashCards array
             $flashCards = json_decode(MediabirdUtility::getArgNoSlashes($args['trainingSession']));
             $result = true;
             foreach ($flashCards as $flashCard) {
                 $trainingResults = 0;
                 for ($i = 0; $i < sizeof($flashCard->results); $i++) {
                     $trainingResults |= pow(4, $i) * $flashCard->results[$i];
                 }
                 if ($flashCard->number == 0) {
                     $mediabirdDb->deleteRecords(MediabirdConfig::tableName('Flashcard', true), "marker={$flashCard->marker} AND user_id={$auth->userId}");
                 }
                 $flashcard = (object) null;
                 $flashcard->marker = $flashCard->marker;
                 $flashcard->user_id = $auth->userId;
                 $flashcard->num = $flashCard->number;
                 $flashcard->level_num = $flashCard->level;
                 $flashcard->lastTimeAnswered = $flashCard->lastTimeAnswered;
                 $flashcard->markedForRepetition = $flashCard->markedForRepetition;
                 $flashcard->results = $trainingResults;
                 $result = $result && $mediabirdDb->insertRecord(MediabirdConfig::tableName('Flashcard', true), $flashcard);
             }
             if ($result) {
                 $reply->success = true;
             } else {
                 $reply->error = "database error";
             }
             break;
         case "reportAbuse":
             //file an abuse report
             $id = $args['id'];
             $type = $args['type'];
             $body = "User with id {$auth->userId} has reported a violation against the Terms of Use.\nConcerned type: {$type}\nConcerned content id: {$id}\n";
             if (!MediabirdConfig::$disable_mail) {
                 $oldReporting = error_reporting(0);
                 if (method_exists($auth, 'sendMail') && $auth->sendMail(-1, "Terms of Use violation report", $body)) {
                     $reply->success = true;
                 } else {
                     $reply->error = "errorsending";
                 }
                 error_reporting($oldReporting);
             } else {
                 error_log("Abuse reported by user {$auth->userId} for data type {$type} and data id {$id}.");
                 $reply->success = true;
             }
             break;
         case "suggestFeature":
             //file a suggestion
             $description = MediabirdUtility::getArgNoSlashes($args['description']);
             $body = "User with id {$auth->userId} has suggested the following feature:\n" . $description;
             $body = wordwrap($body, 70);
             if (!MediabirdConfig::$disable_mail) {
                 $oldReporting = error_reporting(0);
                 if (method_exists($auth, 'sendMail') && $auth->sendMail(-1, "Mediabird Feedback", $body)) {
                     $reply->success = true;
                 } else {
                     $reply->error = "errorsending";
                 }
                 error_reporting($oldReporting);
             } else {
                 error_log("Feature suggested by user {$auth->userId}: {$description} .");
                 $reply->success = true;
             }
             break;
         case "changePass":
             $current = MediabirdUtility::getArgNoSlashes($args['current']);
             $newpass = MediabirdUtility::getArgNoSlashes($args['newpass']);
             if ($current == $newpass) {
                 $reply->success = true;
             } else {
                 if ($user = $mediabirdDb->getRecord(MediabirdConfig::tableName("User", true), "id={$auth->userId}")) {
                     if ($user->password == $current) {
                         $user->password = $newpass;
                         if ($mediabirdDb->updateRecord(MediabirdConfig::tableName("User", true), $user)) {
                             $reply->success = true;
                         }
                     } else {
                         $reply->error = "wrongpass";
                     }
                 }
             }
             break;
         case "deleteAccount":
             //delete the current account
             $current = MediabirdUtility::getArgNoSlashes($args['current']);
             $query = "SELECT email,name FROM " . MediabirdConfig::tableName('User') . " WHERE id={$auth->userId} AND password='******'";
             $result = $mediabirdDb->getRecordSet($query);
             if ($result && $mediabirdDb->recordLength($result) == 1) {
                 //fetch user info
                 $results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result));
                 $name = $results['name'];
                 $email = $results['email'];
                 //delete user
                 $result = $mediabirdDb->deleteRecords(MediabirdConfig::tableName('User', true), "id={$auth->userId} AND password='******'");
                 //also delete topics
                 $query = "SELECT id FROM " . MediabirdConfig::tableName('Topic') . " WHERE user_id={$auth->userId}";
                 $result = $mediabirdDb->getRecordSet($query);
                 if ($result) {
                     while ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result))) {
                         $topicId = $results['id'];
                         $dataHandler->deleteTopic($topicId);
                     }
                 }
                 $userfolder = ".MediabirdConfig::{$uploads_folder}." . $auth->userId . DIRECTORY_SEPARATOR;
                 if (file_exists($userfolder)) {
                     $oldReporting = error_reporting(0);
                     MediabirdUtility::deleteFolder($userfolder);
                     error_reporting($oldReporting);
                 }
                 //notify user
                 $body = "Your account '{$name}' has been deleted and all associated personal data has been erased.\nWe hope you enjoyed using Mediabird. You are welcome back anytime.\nYour Mediabird team.";
                 if (!MediabirdConfig::$disable_mail) {
                     $oldReporting = error_reporting(0);
                     if (method_exists($auth, 'sendMail') && $auth->sendMail($email, "Account cancelled", $body)) {
                         $reply->success = true;
                     } else {
                         $reply->error = "errorsending";
                     }
                     error_reporting($oldReporting);
                 }
                 //restart session!
                 $auth->restartSession();
                 $reply->success = true;
             } else {
                 $reply->error = "wrongpass";
             }
             break;
         case "checkOutCard":
             //checks out a card for editing
             $cardid = intval($args['id']);
             $minuteAgo = $mediabirdDb->datetime(time() - 60);
             $select = "id={$cardid} AND (locked_by IN (0,{$auth->userId}) OR locked_time < '{$minuteAgo}')";
             if ($card = $mediabirdDb->getRecord(MediabirdConfig::tableName('Card', true), $select)) {
                 $topicId = $card->topic;
                 if ($topic = $mediabirdDb->getRecord(MediabirdConfig::tableName('Topic', true), "id={$topicId}")) {
                     //attempt to load topic as owner
                     if ($topic->user_id != $auth->userId) {
                         if ($dataHandler->getTopicRights($topicId) < MediabirdTopicAccessConstants::allowViewingCards) {
                             $reply->error = "accessdenied";
                             break;
                         }
                     }
                     //access okay
                     $reply->revision = intval($card->revision);
                     $card->locked_by = $auth->userId;
                     $card->locked_time = $mediabirdDb->datetime(time());
                     if ($mediabirdDb->updateRecord(MediabirdConfig::tableName('Card', true), $card)) {
                         $reply->success = true;
                     } else {
                         error_log("could not update card " . print_r($card, true));
                         $reply->error = "database error";
                     }
                 } else {
                     $reply->error = "database error";
                 }
             } else {
                 $reply->error = "locked";
             }
             break;
         case "checkInCard":
             //releases a content card lock
             $cardid = intval($args['id']);
             if ($card = $mediabirdDb->getRecord(MediabirdConfig::tableName('Card', true), "id={$cardid} AND locked_by={$auth->userId}")) {
                 $card->locked_by = 0;
                 if ($mediabirdDb->updateRecord(MediabirdConfig::tableName('Card', true), $card)) {
                     $reply->success = true;
                 } else {
                     $reply->error = "database error";
                 }
             } else {
                 $reply->error = "database error";
             }
             break;
         case "loadNotifications":
             //feed.title, feed.message_type
             $query = "SELECT id, object_id, object_type, user_id, feed_id FROM " . MediabirdConfig::tableName('FeedMessage') . "\n\t\t\t\tfeed_id = ANY (SELECT feed_id FROM " . MediabirdConfig::tableName('FeedSubscription') . " WHERE user_id={$auth->userId}) AND user_id = ANY\n\t\t\t\t\t(SELECT user_id FROM " . MediabirdConfig::tableName('Membership') . " WHERE active=1 AND user_id <> {$auth->userId} AND group_id = ANY\n\t\t\t\t\t (SELECT group_id FROM " . MediabirdConfig::tableName('Membership') . " WHERE active=1 AND user_id <> {$auth->userId})\n\t\t\t\t\t ) AND message.id NOT IN \n\t\t\t\t\t ( SELECT message_id FROM " . MediabirdConfig::tableName('FeedMessagesStatus') . " WHERE user_id={$auth->userId} AND status=1 )\n\t\t\t\t\t  GROUP BY id";
             if ($result = $mediabirdDb->getRecordSet($query)) {
                 $feedMessages = (array) null;
                 while ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result))) {
                     $feedMessage = (object) null;
                     $feedMessage->id = intval($results['id']);
                     $feedMessage->feedId = intval($results['feed_id']);
                     $feedMessage->objectId = intval($results['object_id']);
                     $feedMessage->objectType = intval($results['object_type']);
                     $feedMessage->userId = intval($results['user_id']);
                     $feedMessages[] = $feedMessage;
                 }
                 //collect feed ids
                 $feedIds = array();
                 foreach ($feedMessages as $feedMessage) {
                     if (!in_array($feedMessage->feedId, $feedIds)) {
                         array_push($feedIds, $feedMessage->feedId);
                     }
                 }
                 if ($records = $mediabirdDb->getRecords(MediabirdConfig::tableName('Feed', true), "id IN (" . join(",", $feedIds) . ")", '', "id,title,message_type")) {
                     foreach ($feedMessages as $fi => $feedMessage) {
                         foreach ($records as $record) {
                             if ($record->id == $feedMessage->feedId) {
                                 $feedMessage->messageType = $record->message_type;
                                 $feedMessage->feedTitle = $record->title;
                                 $feedMessages[$fi] = $feedMessage;
                                 break;
                             }
                         }
                     }
                 }
                 $reply->notifications = $feedMessages;
                 $reply->success = true;
             } else {
                 error_log($query);
                 $reply->error = "database error";
             }
             break;
         case "markNotificationAsRead":
             $id = intval($args['id']);
             //check if $id valid
             $query = "SELECT id,status FROM " . MediabirdConfig::tableName('FeedMessagesStatus') . " WHERE user_id={$auth->userId} AND message_id={$id} ";
             if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1) {
                 if ($results = $mediabirdDb->fetchNextRecord($result)) {
                     $statusId = intval($results->id);
                     $statusStatus = intval($results->status);
                     if ($statusStatus != 1) {
                         $messagesStatus = (object) null;
                         $messagesStatus->id = $statusId;
                         $messagesStatus->status = 1;
                         if ($mediabirdDb->updateRecord(MediabirdConfig::tableName('FeedMessagesStatus', true), $messagesStatus)) {
                             $reply->success = true;
                         } else {
                             error_log($query);
                             $reply->error = "database error";
                         }
                     } else {
                         $reply->success = true;
                     }
                 } else {
                     error_log($query);
                     $reply->error = "database error";
                 }
             } else {
                 $feedDB = (object) null;
                 $feedDB->message_id = $id;
                 $feedDB->status = 1;
                 $feedDB->user_id = $auth->userId;
                 if ($mediabirdDb->insertRecord(MediabirdConfig::tableName('FeedMessagesStatus', true), $feedDB)) {
                     $reply->success = true;
                 } else {
                     error_log($query);
                     $reply->error = "database error";
                 }
             }
             break;
         case "getCardsWithMarker":
             $type = $args['tool'];
             $select = "id IN (\n\t\t\t\t\tSELECT card FROM " . MediabirdConfig::tableName('Marker') . " WHERE  notify>0 AND tool='" . $mediabirdDb->escape($type) . "'  \n\t\t\t\t\t\tAND (shared = 1 OR user_id = {$auth->userId})\n\t\t\t\t\t)\n\t\t\t\t\tAND (\n\t\t\t\t\t\ttopic IN (\n\t\t\t\t\t\t\tSELECT id FROM " . MediabirdConfig::tableName('Topic') . " WHERE user_id={$auth->userId}\n\t\t\t\t\t\t)\n\t\t\t\t\t\tOR\n\t\t\t\t\t\ttopic IN (\n\t\t\t\t\t\t\tSELECT topic FROM " . MediabirdConfig::tableName('Right') . " WHERE group_id IN (\n\t\t\t\t\t\t\t\tSELECT group_id FROM " . MediabirdConfig::tableName('Membership') . " WHERE user_id={$auth->userId} AND active=1\n\t\t\t\t\t\t\t)\n\t\t\t\t\t\t)\n\t\t\t\t\t)";
             $cards = (array) null;
             if ($results = $mediabirdDb->getRecords(MediabirdConfig::tableName('Card', true), $select, 'created DESC', 'id')) {
                 foreach ($results as $result) {
                     $card = (object) null;
                     $card->id = intval($result->id);
                     $cards[] = $card;
                 }
             }
             $reply->cards = $cards;
             $reply->success = true;
             break;
         case "loadGroups":
             $referredUsers = (array) null;
             //retrieve all groups where current user is member and public groups
             $query = "SELECT * FROM " . MediabirdConfig::tableName('Group') . " WHERE id=ANY (SELECT group_id FROM " . MediabirdConfig::tableName('Membership') . " WHERE user_id={$auth->userId}) OR access_num>0";
             $reply->groups = (array) null;
             if ($result = $mediabirdDb->getRecordSet($query)) {
                 while ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result))) {
                     $group = (object) null;
                     $group->id = intval($results['id']);
                     $group->name = $results['name'];
                     $group->category = $results['category'];
                     $group->description = $results['description'];
                     $group->access = intval($results['access_num']);
                     //check for own membership
                     $query = "SELECT level_num,active FROM " . MediabirdConfig::tableName('Membership') . " WHERE group_id={$group->id} AND user_id={$auth->userId}";
                     if (($resultMember = $mediabirdDb->getRecordSet($query)) && ($results = $mediabirdDb->fetchNextRecord($resultMember))) {
                         $memberMe = (object) null;
                         $memberMe->user = $auth->userId;
                         $memberMe->enabled = intval($results->active);
                         $memberMe->level = intval($results->level_num);
                         $group->members[] = $memberMe;
                     }
                     //retrieve all members!
                     $query = "SELECT user_id,level_num,active FROM " . MediabirdConfig::tableName('Membership') . " WHERE group_id={$group->id} AND user_id<>{$auth->userId}";
                     if (!isset($memberMe) || $memberMe->enabled != 1 && $memberMe->enabled != 3) {
                         //if not member of group or (requested or invited by a member) -> only show active members, hide invitees and requesters
                         $query .= " AND active=1";
                     }
                     if ($resultMembers = $mediabirdDb->getRecordSet($query)) {
                         while ($resultsMember = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($resultMembers))) {
                             $member = (object) null;
                             $member->user = intval($resultsMember['user_id']);
                             if (array_search($member->user, $referredUsers) === false) {
                                 $referredUsers[] = $member->user;
                             }
                             $member->enabled = intval($resultsMember['active']);
                             $member->level = intval($resultsMember['level_num']);
                             $group->members[] = $member;
                         }
                     }
                     $reply->groups[] = $group;
                 }
             } else {
                 $reply->error = "database error";
                 error_log($query);
             }
             $users = (array) null;
             if (count($referredUsers) > 0) {
                 $query = "SELECT id,name,email FROM " . MediabirdConfig::tableName('User') . " WHERE id IN (" . join(",", $referredUsers) . ")";
                 if ($result = $mediabirdDb->getRecordSet($query)) {
                     while ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result))) {
                         $userInfo = (object) null;
                         $userInfo->id = intval($results['id']);
                         $userInfo->name = $results['name'];
                         $userInfo->email = $results['email'];
                         $users[] = $userInfo;
                     }
                     $reply->success = true;
                 } else {
                     $reply->error = "database error";
                     error_log($query);
                 }
             } else {
                 $reply->success = true;
             }
             $reply->userNames = $users;
             if (isset($args['includeKnown']) && method_exists($auth, 'getKnownUsers')) {
                 $externalUsersTemp = $auth->getKnownUsers();
                 $externalUsers = array();
                 foreach ($externalUsersTemp as $externalTemp) {
                     $found = false;
                     if (property_exists($externalTemp, 'mb_id')) {
                         foreach ($users as $user) {
                             if ($user->id == $externalTemp->mb_id) {
                                 $found = true;
                             }
                         }
                     }
                     if (!$found) {
                         array_push($externalUsers, $externalTemp);
                     }
                 }
                 $reply->externalUsers = $externalUsers;
             }
             break;
         case "updateGroup":
             $groupId = intval(MediabirdUtility::getArgNoSlashes($args['id']));
             $properties = json_decode(MediabirdUtility::getArgNoSlashes($args['group']));
             //check for own membership
             $query = "SELECT level_num,active FROM " . MediabirdConfig::tableName('Membership') . " WHERE group_id={$groupId} AND user_id={$auth->userId}";
             $memberMe = (object) null;
             if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1 && ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result)))) {
                 if (intval($results['level_num']) >= MediabirdConstants::groupLevelAdmin) {
                     //we are admin and allowed to change it
                     $groupDB = (object) null;
                     $groupDB->access_num = $properties->access;
                     $groupDB->name = $properties->name;
                     $groupDB->category = $properties->category;
                     $groupDB->description = $properties->description;
                     $groupDB->modified = $mediabirdDb->datetime(time());
                     $groupDB->id = $groupId;
                     if ($mediabirdDb->updateRecord(MediabirdConfig::tableName('Group', true), $groupDB)) {
                         $reply->access = intval($properties->access);
                         $reply->name = $properties->name;
                         $reply->category = $properties->category;
                         $reply->description = $properties->description;
                         $reply->success = true;
                     }
                 } else {
                     $reply->error = "norights";
                 }
             } else {
                 $reply->error = "database error";
             }
             break;
         case "createGroup":
             $group_raw = json_decode(MediabirdUtility::getArgNoSlashes($args['group']));
             $group = (object) null;
             $group->name = $group_raw->name;
             $group->description = $group_raw->description;
             $group->category = $group_raw->category;
             $group->type = 0;
             $group->access_num = $group_raw->access;
             $group->created = $mediabirdDb->datetime(time());
             $group->modified = $mediabirdDb->datetime(time());
             if ($id = $mediabirdDb->insertRecord(MediabirdConfig::tableName('Group', true), $group)) {
                 $group->id = intval($id);
                 $group->access = $group->access_num;
                 unset($group->access_num);
                 unset($group->created);
                 unset($group->modified);
                 //create membership with admin level
                 $membershipDB = (object) null;
                 $membershipDB->group_id = $group->id;
                 $membershipDB->user_id = $auth->userId;
                 $membershipDB->level_num = MediabirdConstants::groupLevelAdmin;
                 $membershipDB->active = 1;
                 $membershipDB->created = $mediabirdDb->datetime(time());
                 $membershipDB->modified = $mediabirdDb->datetime(time());
                 if ($id = $mediabirdDb->insertRecord(MediabirdConfig::tableName('Membership', true), $membershipDB)) {
                     $membership = (object) null;
                     $membership->id = intval($id);
                     $membership->enabled = $membershipDB->active;
                     $membership->level = $membershipDB->level_num;
                     $membership->user = $membershipDB->user_id;
                     $group->members[] = $membership;
                     $reply->success = true;
                     $reply->group = $group;
                 } else {
                     error_log("membership");
                     $reply->error = "database error";
                 }
             } else {
                 error_log("group");
                 $reply->error = "database error";
             }
             break;
         case "inviteToGroup":
             $groupId = intval(MediabirdUtility::getArgNoSlashes($args['group']));
             //users identifyable by id, i.e. mediabird members
             if (isset($args['ids']) && strlen($args['ids']) > 0) {
                 $ids = MediabirdUtility::getArgNoSlashes($args['ids']);
                 $ids = split(",", $ids);
             } else {
                 $ids = (array) null;
             }
             if (isset($args['names']) && strlen($args['names']) > 0) {
                 $emails = MediabirdUtility::getArgNoSlashes($args['names']);
                 $emails = split(",", $emails);
             } else {
                 $emails = (array) null;
             }
             //array containing users that have just been invited
             $unknownInvitees = (array) null;
             if (isset($args['externalIds']) && strlen($args['externalIds']) > 0 && method_exists($auth, 'inviteKnownUser')) {
                 $externalIds = MediabirdUtility::getArgNoSlashes($args['externalIds']);
                 //users known from a mediabird embedding plattform
                 $externalIds = split(",", $externalIds);
                 $inviteeUnknown = false;
                 // variable to receive a value whether the user is already using Mediabird or not
                 foreach ($externalIds as $eId) {
                     if ($internalId = $auth->inviteKnownUser($eId, $inviteeUnknown)) {
                         if ($inviteeUnknown) {
                             array_push($unknownInvitees, $internalId);
                         }
                         array_push($ids, $internalId);
                     }
                 }
             }
             if (count($ids) > 0 || count($emails) > 0) {
                 //check for own membership
                 $query = "SELECT level_num,active FROM " . MediabirdConfig::tableName('Membership') . " WHERE group_id={$groupId} AND user_id={$auth->userId}";
                 $memberMe = (object) null;
                 if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1 && ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result)))) {
                     $memberMe->user = $auth->userId;
                     $memberMe->enabled = intval($results['active']);
                     $memberMe->level = intval($results['level_num']);
                 }
                 //check for invite rights
                 $query = "SELECT access_num FROM " . MediabirdConfig::tableName('Group') . " WHERE id={$groupId}";
                 if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1 && ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result)))) {
                     if (isset($memberMe) && $memberMe->level >= MediabirdConstants::groupLevelAdmin || intval($results['access_num']) > 0) {
                         //current user is admin or group is public
                         if (count($ids) != 0) {
                             foreach ($ids as $i => $id) {
                                 $ids[$i] = intval($id);
                             }
                         }
                         if (count($emails) > 0) {
                             foreach ($emails as $i => $email) {
                                 if (MediabirdUtility::checkEmail($email)) {
                                     //checks if email has a valid format
                                     $query = "SELECT id FROM " . MediabirdConfig::tableName('User') . " WHERE email='" . $mediabirdDb->escape($email) . "'";
                                     if ($result = $mediabirdDb->getRecordSet($query)) {
                                         if ($results = $mediabirdDb->fetchNextRecord($result)) {
                                             $emailUserId = intval($results->id);
                                             if (array_search($emailUserId, $ids) === false) {
                                                 $ids[] = $emailUserId;
                                             }
                                         } else {
                                             if (!method_exists($auth, "inviteUser")) {
                                                 if (!property_exists($reply, "notfound")) {
                                                     $reply->notfound = (array) null;
                                                 }
                                                 $reply->notfound[] = $email;
                                             } else {
                                                 // users unknown to the system are invited per mail here
                                                 // using the auth interface to allow for external email invitation
                                                 $mailSuccess = $auth->inviteUser($email);
                                                 if ($mailSuccess) {
                                                     $ids[] = $mailSuccess;
                                                     $unknownInvitees[] = $mailSuccess;
                                                 } else {
                                                     $reply->notfound[] = $email;
                                                 }
                                             }
                                         }
                                     }
                                 }
                             }
                         }
                         //find valid ids
                         $query = "SELECT id FROM " . MediabirdConfig::tableName('User') . " WHERE id<>{$auth->userId} AND ";
                         if (count($ids) > 0) {
                             $query .= "id IN (" . join(",", $ids) . ")";
                         } else {
                             $query .= "0=1";
                         }
                         if ($result = $mediabirdDb->getRecordSet($query)) {
                             while ($results = $mediabirdDb->fetchNextRecord($result)) {
                                 $inviteId = intval($results->id);
                                 //check if user is already member of group
                                 $select = "user_id={$inviteId} AND group_id={$groupId}";
                                 if (!$mediabirdDb->getRecord(MediabirdConfig::tableName('Membership', true), $select)) {
                                     if ($memberMe->level >= MediabirdConstants::groupLevelAdmin) {
                                         if (in_array($inviteId, $unknownInvitees)) {
                                             // if user has just been invited to Mediabird, a full membership is created
                                             // new user will be able to find shared topic when having logged in
                                             $enabled = 1;
                                         } else {
                                             $enabled = 3;
                                         }
                                     } else {
                                         $enabled = 2;
                                     }
                                     $membershipDB = (object) null;
                                     $membershipDB->user_id = $inviteId;
                                     $membershipDB->group_id = $groupId;
                                     $membershipDB->active = $enabled;
                                     $membershipDB->created = $mediabirdDb->datetime(time());
                                     $membershipDB->modified = $mediabirdDb->datetime(time());
                                     if ($mediabirdDb->insertRecord(MediabirdConfig::tableName('Membership', true), $membershipDB)) {
                                         if (!property_exists($reply, "invited")) {
                                             $reply->invited = (array) null;
                                         }
                                         $reply->invited[] = $inviteId;
                                     } else {
                                         $reply->error = "database error";
                                     }
                                 }
                             }
                         } else {
                             error_log($query);
                             $reply->error = "database error";
                         }
                         if (!isset($reply->error)) {
                             $reply->success = true;
                         }
                     } else {
                         $reply->error = "norights";
                     }
                 } else {
                     error_log($query);
                     $reply->error = "database error";
                 }
             } else {
                 $reply->state = "emptylist";
             }
             break;
         case "joinGroup":
             $groupId = intval(MediabirdUtility::getArgNoSlashes($args['id']));
             //test if already joined
             $query = "SELECT id,active FROM " . MediabirdConfig::tableName('Membership') . " WHERE user_id={$auth->userId} AND group_id={$groupId}";
             if ($result = $mediabirdDb->getRecordSet($query)) {
                 $resultssCount = $mediabirdDb->recordLength($result);
                 $enabled = 0;
                 if ($resultssCount > 0 && ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result)))) {
                     $memberId = intval($results['id']);
                     $enabled = intval($results['active']);
                     $reply->state = $enabled;
                 }
                 if ($resultssCount == 0 || $enabled >= 2) {
                     //not a member or was invited
                     //check if user is allowed to join or request, or confirm invitation
                     $query = "SELECT access_num FROM " . MediabirdConfig::tableName('Group') . " WHERE id={$groupId}";
                     if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1) {
                         $results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result));
                         $access = intval($results['access_num']);
                         //enabled = 3 means was invited by admin
                         if ($enabled != 3 && $access == 0) {
                             //access denied!
                             $reply->error = "access denied";
                         } else {
                             if ($resultssCount == 0) {
                                 //request
                                 if ($access == 1) {
                                     $enabled = 0;
                                 } else {
                                     $enabled = 1;
                                 }
                                 $membershipDB = (object) null;
                                 $membershipDB->user_id = $auth->userId;
                                 $membershipDB->group_id = $groupId;
                                 $membershipDB->active = $enabled;
                                 $membershipDB->created = $mediabirdDb->datetime(time());
                                 $membershipDB->modified = $mediabirdDb->datetime(time());
                                 if ($mediabirdDb->insertRecord(MediabirdConfig::tableName('Membership', true), $membershipDB)) {
                                     $reply->state = $enabled;
                                 }
                                 $reply->created = true;
                             } else {
                                 //confirm invitation
                                 if ($enabled == 3 || $access > 1) {
                                     $enabled = 1;
                                 } else {
                                     $enabled = 0;
                                 }
                                 $membership = (object) null;
                                 $membership->id = $memberId;
                                 $membership->active = $enabled;
                                 $membership->modified = $mediabirdDb->datetime(time());
                                 if ($mediabirdDb->updateRecord(MediabirdConfig::tableName('Membership', true), $membership)) {
                                     $reply->state = $enabled;
                                 }
                             }
                         }
                     }
                 }
             }
             if (property_exists($reply, "state")) {
                 $reply->success = true;
             } else {
                 if (!isset($reply->error)) {
                     $reply->error = "database error";
                 }
             }
             break;
         case "updateMember":
             //promote, accept or remove member
             $groupId = intval(MediabirdUtility::getArgNoSlashes($args['group']));
             $memberUserId = intval(MediabirdUtility::getArgNoSlashes($args['user']));
             $level = intval(MediabirdUtility::getArgNoSlashes($args['level']));
             $enabled = intval(MediabirdUtility::getArgNoSlashes($args['enabled']));
             //check if user has admin rights
             $query = "SELECT id FROM " . MediabirdConfig::tableName('Membership') . " WHERE group_id={$groupId} AND user_id={$auth->userId} AND (level_num >= " . MediabirdConstants::groupLevelAdmin . ")";
             if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1) {
                 if ($memberUserId != $auth->userId) {
                     if ($level != -1) {
                         //check if there is a user that can be promoted
                         $membershipDB = $mediabirdDb->getRecord(MediabirdConfig::tableName('Membership', true), "group_id={$groupId} AND user_id={$memberUserId} AND active=0");
                         $membershipDB->level_num = $level;
                         $membershipDB->active = $enabled;
                         $membershipDB->modified = $mediabirdDb->datetime(time());
                         if ($mediabirdDb->updateRecord(MediabirdConfig::tableName('Membership', true), $membershipDB)) {
                             $reply->success = true;
                             $reply->level = $level;
                             $reply->enabled = $enabled;
                         } else {
                             $reply->error = "nomember";
                         }
                     } else {
                         if ($dataHandler->deleteMembership($memberUserId, $groupId)) {
                             $reply->success = true;
                             $reply->level = -1;
                         } else {
                             $reply->error = "database error";
                         }
                     }
                 } else {
                     if ($level == -1) {
                         $reply->error = "cannotremoveownmembership";
                     } else {
                         //only allow demoting oneself if there is at least one other admin!
                         $query = "SELECT FROM " . MediabirdConfig::tableName('Membership') . " WHERE group_id={$groupId} AND user_id<>{$auth->userId} AND (level_num >= " . MediabirdConstants::groupLevelAdmin . ")";
                         if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) > 0) {
                             //demoting allowed
                             $membershipDB = $mediabirdDb->getRecord(MediabirdConfig::tableName('Membership', true), "group_id={$groupId} AND user_id={$memberUserId}");
                             $membershipDB->level_num = $level;
                             $membershipDB->active = $enabled;
                             $membershipDB->modified = $mediabirdDb->datetime(time());
                             if ($mediabirdDb->updateRecord(MediabirdConfig::tableName('Membership', true), $membershipDB)) {
                                 $reply->success = true;
                                 $reply->level = $level;
                                 $reply->enabled = $enabled;
                             } else {
                                 $reply->error = "database error";
                             }
                         } else {
                             $reply->error = "notenoughadmins";
                         }
                     }
                 }
             } else {
                 $reply->error = "norights";
             }
             break;
         case "leaveGroup":
             $groupId = intval(MediabirdUtility::getArgNoSlashes($args['id']));
             //check for further admins
             $query = "SELECT user_id FROM " . MediabirdConfig::tableName('Membership') . " WHERE group_id={$groupId} AND (level_num >= " . MediabirdConstants::groupLevelAdmin . ")";
             if ($result = $mediabirdDb->getRecordSet($query)) {
                 $removeMembership = true;
                 if ($mediabirdDb->recordLength($result) == 1) {
                     $results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result));
                     if (intval($results['user_id']) == $auth->userId) {
                         //user is only admin of group, promote to next member
                         $query = "SELECT id FROM " . MediabirdConfig::tableName('Membership') . " WHERE group_id={$groupId} AND user_id <> {$auth->userId}";
                         if ($result = $mediabirdDb->getRecordSet($query)) {
                             if ($mediabirdDb->recordLength($result) > 0) {
                                 if ($membershipDB = $mediabirdDb->getRecord(MediabirdConfig::tableName('Membership', true), "group_id={$groupId} AND user_id <> {$auth->userId} AND active=1")) {
                                     $membershipDB->level_num = MediabirdConstants::groupLevelAdmin;
                                     $membershipDB->modified = $mediabirdDb->datetime(time());
                                     if ($mediabirdDb->updateRecord(MediabirdConfig::tableName('Membership', true), $membershipDB)) {
                                         $reply->state = "foundnewadmin";
                                     } else {
                                         $removeMembership = false;
                                     }
                                 } else {
                                     $removeMembership = false;
                                 }
                             } else {
                                 //no user left, delete group!
                                 if ($dataHandler->deleteGroup($groupId)) {
                                     $reply->state = "groupremoved";
                                 } else {
                                     $removeMembership = false;
                                 }
                             }
                         } else {
                             $removeMembership = false;
                         }
                     }
                 }
                 if ($removeMembership) {
                     if ($dataHandler->deleteMembership($auth->userId, $groupId)) {
                         $reply->success = true;
                     } else {
                         $reply->error = "database error";
                     }
                 } else {
                     $reply->error = "nonewadmin";
                 }
             } else {
                 $reply->error = "database error";
             }
             break;
         case "shareTopic":
             $topicId = intval(MediabirdUtility::getArgNoSlashes($args['topic']));
             $groupId = intval(MediabirdUtility::getArgNoSlashes($args['group']));
             $mask = intval(MediabirdUtility::getArgNoSlashes($args['mask']));
             //check if user is owner of topic
             $query = "SELECT user_id FROM " . MediabirdConfig::tableName('Topic') . " WHERE id={$topicId}";
             if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1) {
                 $result = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result));
                 $owner = intval($result['user_id']);
                 if ($owner == $auth->userId) {
                     //check if user is member of group
                     $query = "SELECT id FROM " . MediabirdConfig::tableName('Membership') . " WHERE group_id={$groupId} AND user_id={$auth->userId} AND active=1";
                     if (($result = $mediabirdDb->getRecordSet($query)) && $mediabirdDb->recordLength($result) == 1) {
                         //user is member of group, check if already shared
                         $query = "SELECT id,mask FROM " . MediabirdConfig::tableName('Right') . " WHERE topic={$topicId} AND group_id={$groupId}";
                         if ($result = $mediabirdDb->getRecordSet($query)) {
                             if ($mediabirdDb->recordLength($result) == 0) {
                                 //share
                                 $right = (object) null;
                                 $right->topic = $topicId;
                                 $right->group_id = $groupId;
                                 $right->mask = $mask;
                                 if ($rightId = $mediabirdDb->insertRecord(MediabirdConfig::tableName('Right', true), $right)) {
                                     $reply->mask = $mask;
                                     $reply->id = $rightId;
                                     $reply->success = true;
                                 } else {
                                     $reply->error = "database error";
                                 }
                             } else {
                                 if ($results = $mediabirdDb->recordToArray($mediabirdDb->fetchNextRecord($result))) {
                                     $reply->id = intval($results['id']);
                                     $reply->mask = $mask;
                                     $currentMask = intval($results['mask']);
                                     if ($currentMask != $mask) {
                                         $rightDB = (object) null;
                                         $rightDB->id = $reply->id;
                                         $rightDB->mask = $mask;
                                         if ($mediabirdDb->updateRecord(MediabirdConfig::tableName('Right', true), $rightDB)) {
                                             $reply->success = true;
                                         } else {
                                             $reply->error = "database error";
                                         }
                                     } else {
                                         $reply->success = true;
                                     }
                                 } else {
                                     $reply->error = "database error";
                                 }
                             }
                         } else {
                             $reply->error = "database error";
                         }
                     } else {
                         $reply->error = "notmember";
                     }
                 } else {
                     $reply->error = "notowner";
                 }
             }
             break;
         case "searchDatabase":
             $query = MediabirdUtility::getArgNoSlashes($args['query']);
             $type = intval($args['type']);
             if ($results = $dataHandler->searchDatabase($query, $type)) {
                 $reply->groups = $results[0];
                 $reply->topics = $results[1];
                 $reply->cards = $results[2];
                 $reply->success = true;
             } else {
                 $reply->error = "database error";
             }
             break;
         case "checkEquationSupport":
             $reply->exists = class_exists("LatexRender", false) && file_exists(MediabirdConfig::$latex_path) && file_exists(MediabirdConfig::$convert_path);
             break;
         case "renderEquation":
             if (class_exists("LatexRender") && isset($args["topic"]) && isset($args["equation"])) {
                 $topic = intval($args["topic"]);
                 if (MediabirdUtility::checkAccess($topic, $auth->userId)) {
                     $userFolder = MediabirdConfig::$uploads_folder;
                     if (property_exists($auth, "userSubfolder")) {
                         $userFolder .= $auth->userSubfolder . DIRECTORY_SEPARATOR;
                     } else {
                         $userFolder .= $auth->userId . DIRECTORY_SEPARATOR;
                     }
                     if (!file_exists($userFolder)) {
                         mkdir($userFolder, 0777, true);
                     }
                     $userQuota = MediabirdUtility::getUserQuota($auth->userId);
                     $quotaLeft = MediabirdUtility::quotaLeft($auth->userId, $userQuota);
                     $equation = MediabirdUtility::getArgNoSlashes($args["equation"]);
                     $renderer = new LatexRender($userFolder, "", MediabirdConfig::$cache_folder);
                     $renderer->_latex_path = MediabirdConfig::$latex_path;
                     $renderer->_convert_path = MediabirdConfig::$convert_path;
                     $resultFile = $renderer->checkFormulaCache($equation);
                     if (!$resultFile) {
                         $resultFile = $renderer->renderLatex($equation);
                         if ($resultFile && file_exists($resultFile)) {
                             $fileSize = filesize($resultFile);
                             if ($fileSize < $quotaLeft || $quotaLeft == -1) {
                                 $status_code = copy($resultFile, $renderer->destinationFile);
                                 if (!$status_code) {
                                     $resultFile = null;
                                     $renderer->_errorcode = 6;
                                 } else {
                                     $resultFile = $renderer->destinationFile;
                                 }
                             } else {
                                 $resultFile = null;
                                 $renderer->_errorcode = 7;
                                 //not enough quota
                             }
                             $renderer->cleanTemporaryDirectory();
                         } else {
                             $renderer->_errorcode = 3;
                             //could not render file
                         }
                     } else {
                         $resultFile = $userFolder . $resultFile;
                     }
                     $reply = (object) null;
                     if ($resultFile && file_exists($resultFile)) {
                         $resultFile = str_ireplace(MediabirdConfig::$uploads_folder, '', $resultFile);
                         $resultFile = str_replace(DIRECTORY_SEPARATOR, '/', $resultFile);
                         $reply->success = true;
                         $reply->topic = $topic;
                         $reply->filename = $resultFile;
                     } else {
                         $reply->errorcode = $renderer->_errorcode;
                         $reply->error = "latex";
                     }
                 } else {
                     $reply->error = "invalidtopic";
                 }
             }
             break;
     }
     return $reply;
 }