<?php

defined('_JEXEC') or die('Access denied');

jimport('joomla.application.component.helper');
jimport('joomla.application.component.model');
jimport('joomla.base.object');
jimport('joomla.cache.cache');
jimport('joomla.http.http');
jimport('joomla.log.log');

$GLOBALS['THRIFT_ROOT'] = dirname(__FILE__) . DS . 'thrift';
require_once($GLOBALS['THRIFT_ROOT'] . DS . 'Thrift.php');
require_once($GLOBALS['THRIFT_ROOT'] . DS . 'protocol' . DS . 'TBinaryProtocol.php');
require_once($GLOBALS['THRIFT_ROOT'] . DS . 'transport' . DS . 'TSocket.php');
require_once($GLOBALS['THRIFT_ROOT'] . DS . 'transport' . DS . 'TBufferedTransport.php');
require_once($GLOBALS['THRIFT_ROOT'] . DS . 'packages' . DS . 'OpenAIREConnector' . DS . 'OpenAIREConnector.php');

// This model manages alerts using DB and Thrift.
class OpenAireModelAlerts extends JModel {
	const SUBSCRIPTIONS_CACHE_ID = 'subscriptions';
	const TOPICS_CACHE_ID = 'topics';
	const ALERT_MODES_CACHE_ID = 'alert.modes';
	const CACHE_GROUP = 'openaire.alerts';
	const LOG = 'openaire';

	private $databasePrefix;
	private $pageSize;
	private $atomUrn;
	private $jdbcUri;
	private $newsCategory;
	private $newsUser;
	private $twitterAccessToken;
	private $twitterAccessTokenSecret;
	private $transport;
	private $client;
	private $cache;

	// Construct a new OpenAireModelSearch.
	// $configuration the configuration to use		
	public function __construct($configuration = array()) {
		parent :: __construct($configuration);
		$this -> db = JFactory :: getDBO();
		$this -> databasePrefix = JFactory :: getApplication() -> getCfg('dbprefix');
		$parameters = JComponentHelper :: getParams('com_openaire');
		$this -> pageSize = intval($parameters -> get('alertsPageSize'));
		$this -> atomUrn = $parameters -> get('alertsAtomUrn');
		$this -> jdbcUri = $parameters -> get('alertsJdbcUri');
		$this -> newsCategory = intval($parameters -> get('alertsNewsCategory'));
		$this -> newsUser = intval($parameters -> get('alertsNewsUser'));
		$this -> twitterAccessToken = $parameters -> get('alertsTwitterAcccessToken');
		$this -> twitterAccessTokenSecret = $parameters -> get('alertsTwitterAccessTokenSecret');
		$socket = new TSocket($parameters -> get('thriftHost'), intval($parameters -> get('thriftPort')));
		$socket -> setRecvTimeout(intval($parameters -> get('thriftTimeout')));
		$this -> transport = new TBufferedTransport($socket);
		$this -> client = new OpenAireConnectorClient(new TBinaryProtocol($this -> transport));
		$this -> transport -> open();
		$this -> cache = JCache :: getInstance();
	}
	
	// Close Thrift transport.
	public function __destruct() {
		$this -> transport -> close();
	}
	
	// Retrieve the subscriptions of a user using cache if enabled.
	// $user the user to retrieve subscriptions for
	// return the subscriptions of the user specified (array)
	public function getSubscriptions($user) {
		if ($this -> cache -> getCaching()) {
			$id = self :: SUBSCRIPTIONS_CACHE_ID . '.' . $user -> get('username');
			$subscriptions = $this -> cache -> get($id, self :: CACHE_GROUP);
			if ($subscriptions === FALSE) {
				$subscriptions = $this -> _getSubscriptions($user);
				if ($subscriptions !== NULL)
					$this -> cache -> store($subscriptions, $id, self :: CACHE_GROUP);
			}
		} else
			$subscriptions = $this -> _getSubscriptions($user);
		return $subscriptions;
	}
	
	// Retrieve alert topics using cache if enabled.
	// $parent the id of the parent topic of the topics to retrieve
	// $name retrieve only topics whose name contains this substring
	// $limit the maximum number of topics to retrieve
	// return the alert topics matching the criteria specified (array)
	public function getTopics($parent, $name, $limit) {
		if ($this -> cache -> getCaching()) {
			$id = self :: TOPICS_CACHE_ID . '.' . $parent . '.' . $name . '.' . $limit;
			$topics = $this -> cache -> get($id, self :: CACHE_GROUP);
			if ($topics === FALSE) {
				$topics = $this -> _getTopics($parent, $name, $limit);
				if ($topics !== NULL)
					$this -> cache -> store($topics, $id, self :: CACHE_GROUP);
			}
		} else
			$topics = $this -> _getTopics($parent, $name, $limit);
		return $topics;
	}
	
	// Retrieve the alert modes available to a user using cache if enabled.
	// $user the user to retrieve alert modes for
	// return the alert modes available to the user specified (array)
	public function getAlertModes($user) {
		if ($this -> cache -> getCaching()) {
			$id = self :: ALERT_MODES_CACHE_ID . '.' . $user -> get('username');
			$alertModes = $this -> cache -> get($id, self :: CACHE_GROUP);
			if ($alertModes === FALSE) {
				$alertModes = $this -> _getAlertModes($user);
				if ($alertModes !== NULL)
					$this -> cache -> store($alertModes, $id, self :: CACHE_GROUP);
			}
		} else
			$alertModes = $this -> _getAlertModes($user);
		return $alertModes;
	}
	
	// Add a new subcsription using cache if enabled.
	// $templateId the unique identifier of the template of the new subscription
	// $notificationService the notification service of the new subscription
	// $queryId the unique identifier of the query of the new subscription
	// $resultId the unique identifier of the result of the new subscription
	// $alertMode the alert mode of the new subscription
	// $batchPeriod the batch period of the new subscription
	// $user the user to add the new subscription for
	public function addSubscription($templateId, $notificationService, $queryId, $resultId, $alertMode, $batchPeriod, $user) {
		$this -> _addSubscription($templateId, $notificationService, $queryId, $resultId, $alertMode, $batchPeriod, $user);
		if ($this -> cache -> getCaching()) {
			$id = self :: SUBSCRIPTIONS_CACHE_ID . $user -> get('username');
			$this -> cache -> remove($id, self :: CACHE_GROUP);
		}
	}
	
	// Remove a subscription using cache if enabled.
	// $templateId the unique identifier of the template of the subscription to remove
	// $notificationService the notification service of the subscription to remove
	// $queryId the unique identifier of the query of the subscription to remove
	// $resultId the unique identifier of the result of the subscription to remove
	// $alertMode the alert mode of the subscription to remove
	// $subscriber the subscriber URI of the subscription to remove
	// $user the user whose subscription to remove
	public function removeSubscription($templateId, $notificationService, $queryId, $resultId, $alertMode, $subscriber, $user) {
		$this -> _removeSubscription($templateId, $notificationService, $queryId, $resultId, $alertMode, $subscriber);
		if ($this -> cache -> getCaching()) {
			$id = self :: SUBSCRIPTIONS_CACHE_ID . $user -> get('username');
			$this -> cache -> remove($id, self :: CACHE_GROUP);
		}
	}
	
	// Retrieve the subscriptions of a user using cache if enabled.
	// $user the user to retrieve subscriptions for
	// return the subscriptions of the user specified (array) or NULL if any errors occur
	private function _getSubscriptions($user) {
		try {	
			$result = array();
			foreach ($this -> getAlertModes($user) as $alertMode) { // for each alert mode that the current user may use
				list($alertMode -> id, $subscriber) = $this -> getAlertModeAndSubscriber($alertMode -> id, 0, $user);
				for ($offset = 0; ; $offset += $this -> pageSize) {
					$subscriptions = $this -> client -> getSubscriptions($alertMode -> id, $subscriber, $this -> pageSize, $offset);
					foreach ($subscriptions as $subscription) {
						$subscription -> topic = $this -> getFullTopicName($subscription -> templateId, $subscription -> notificationService, $subscription -> queryId, $subscription -> resultId);
						list($subscription -> alertModeName, $subscription -> batchPeriod) = $this -> getAlertModeNameAndBatchPeriod($subscription -> alertMode, $subscription -> subscriber);
						$result[] = $subscription;
					}
					if (count($subscriptions) < $this -> pageSize)
						break;
				}
				if ($alertMode -> batch) { // alert mode is a batch alert mode too
					list($alertMode -> id, $subscriber) = $this -> getAlertModeAndSubscriber($alertMode -> id, NULL, $user);
					for ($offset = 0; ; $offset += $this -> pageSize) {
						$subscriptions = $this -> client -> getSubscriptions($alertMode -> id, $subscriber, $this -> pageSize, $offset);
						foreach ($subscriptions as $subscription) {
							$subscription -> topic = $this -> getFullTopicName($subscription -> templateId, $subscription -> notificationService, $subscription -> queryId, $subscription -> resultId);
							list($subscription -> alertModeName, $subscription -> batchPeriod) = $this -> getAlertModeNameAndBatchPeriod($subscription -> alertMode, $subscription -> subscriber);
							$result[] = $subscription;
						}
						if (count($subscriptions) < $this -> pageSize)
							break;
					}
				}
			}
			// sort subscriptions
			usort($result, function ($subscription1, $subscription2) {
				$topicComparison = strcmp($subscription1 -> topic, $subscription2 -> topic);
				$alertModeComparison = strcmp($subscription1 -> alertModeName, $subscription2 -> alertModeName);
				$batchPeriodComparison = strcmp($subscription1 -> batchPeriod, $subscription2 -> batchPeriod);
				return ($topicComparison == 0) ? (($alertModeComparison == 0) ? $batchPeriodComparison : $alertModeComparison) : $topicComparison;			
			});
			JLog :: add ('Retrieved ' . count($result) . ' subscriptions (user: ' . $user -> get('username') . ')', JLog :: INFO, self :: LOG);
			return $result;
		} catch (Exception $e) {
			JLog :: add('Error retrieving subscriptions (user: ' . $user -> get('username') . '): ' . $e -> getMessage(), JLog :: ERROR, self :: LOG);
			return NULL;
		}
	}

	// Retrieve alert topics.
	// $parent the id of the parent topic of the topcis to retrieve
	// $name retrieve only topics whose name contains this substring
	// $limit the maximum number of topics to retrieve
	// return the alert topics matching the criteria specified (array) or NULL if any errors occur
	private function _getTopics($parent, $name, $limit) {
		try {
			$query = $this -> db -> getQuery(TRUE);
			$query -> select('id, name, description, templateId, notificationService, queryId, resultId');
			$query -> from('#__openaire_topic_hierarchy');
			$query -> where(($parent == NULL) ? 'parent IS NULL' : ('parent = ' . intval($parent)));
			$query -> where('name LIKE CONCAT(\'%\', ' . $this -> db -> quote($name) . ', \'%\')');
			$query -> order('id');
			$this -> db -> setQuery($query, 0, intval($limit));
			$topics = $this -> db -> loadObjectList();
			if ($topics === NULL)
				throw new Exception($this -> db -> getErrorMsg() . ' (' . $this -> db -> getErrorNum() . ')');
			JLog :: add('Retrieved ' . count($topics) . ' topics (parent: ' . (($parent == NULL) ? 'NULL' : $parent) . ', name: ' . $name . ', limit: ' . $limit . ')', JLog :: INFO, self :: LOG);
			return $topics;
		} catch (Exception $e) {
			JLog :: add('Error retrieving topics (parent: ' . (($parent == NULL) ? 'NULL' : $parent) . ', name: ' . $name . ', limit: ' . $limit . '): ' . $e -> getMessage(), JLog :: ERROR, self :: LOG);
			return NULL;
		}
	}
	
	// Retrieve the alert modes available to a user.
	// $user the user to retrieve alert modes for
	// return the alert modes available to the user specified (array) or NULL if any errors occur
	private function _getAlertModes($user) {
		try {
			$query = $this -> db -> getQuery(TRUE);
			$query -> select(array('id', 'name', 'description', 'batch'));
			$query -> from('#__openaire_alert_modes');
			if ($user -> username != 'admin')
				$query -> where('NOT `adminOnly`');
			$this -> db -> setQuery($query);
			$alertModes = $this -> db -> loadObjectList();
			if ($alertModes === NULL)
				throw new Exception($this -> db -> getErrorMsg() . ' (' . $this -> db -> getErrorNum() . ')');
			JLog :: add('Retrieved ' . count($alertModes) . ' alert modes (user: ' . $user -> get('username') . ')', JLog :: INFO, self :: LOG);
			return $alertModes;
		} catch (Exception $e) {
			JLog :: add('Error retrieving alert modes (user: ' . $user -> get('username') . '): ' . $e -> getMessage(), JLog :: ERROR, self :: LOG);
			return NULL;
		}
	}
	
	// Add a new subscription.
	// $templateId the unique identifier of the template of the new subscription
	// $notificationService the notification service of the new subscription
	// $queryId the unique identifier of the query of the new subscription
	// $resultId the unique identifier of the result of the new subscription
	// $alertMode the alert mode of the new subscription
	// $batchPeriod the batch period of the new subscription
	// $user the user to add the new subscription for
	private function _addSubscription($templateId, $notificationService, $queryId, $resultId, $alertMode, $batchPeriod, $user) {
		try {
			list($alertMode, $subscriber) = $this -> getAlertModeAndSubscriber($alertMode, $batchPeriod, $user);
			$this -> client -> addSubscription(new AlertSubscription(array('templateId' => $templateId, 'notificationService' => $notificationService, 'queryId' => $queryId, 'resultId' => $resultId, 'alertMode' => $alertMode, 'subscriber' => $subscriber)));
			JLog :: add('Added subscription (template: ' . $templateId . ', notification service: ' . $notificationService . ', query: ' . $queryId . ', result: ' . $resultId . ', alert mode: ' . $alertMode . ', batch period: ' . $batchPeriod . ', user: ' . $user -> get('username') . ')', JLog :: INFO, self :: LOG);
		} catch (Exception $e) {
			JLog :: add('Error adding subscription (template: ' . $templateId . ', notification service: ' . $notificationService . ', query: ' . $queryId . ', result: ' . $resultId . ', alert mode: ' . $alertMode . ', batch period: ' . $batchPeriod . ', user: ' . $user -> get('username') . '): ' . $e -> getMessage(), JLog :: ERROR, self :: LOG);
		}	
	}
	
	// Remove a subscription.
	// $templateId the unique identifier of the template of the subscription to remove
	// $notificationService the notification service of the subscription to remove
	// $queryId the unique identifier of the query of the subscription to remove
	// $resultId the unique identifier of the result of the subscription to remove
	// $alertMode the alert mode of the subscription to remove
	// $subscriber the subscriber URI of the subscription to remove
	private function _removeSubscription($templateId, $notificationService, $queryId, $resultId, $alertMode, $subscriber) {
		try {
			$this -> client -> removeSubscription(new AlertSubscription(array('templateId' => $templateId, 'notificationService' => $notificationService, 'queryId' => $queryId, 'resultId' => $resultId, 'alertMode' => $alertMode, 'subscriber' => $subscriber)));
			JLog :: add('Removed subscription (template: ' . $templateId . ', notification service: ' . $notificationService . ', query: ' . $queryId . ', result: ' . $resultId . ', alert mode: ' . $alertMode . ', subscriber: ' . $subscriber . ')', JLog :: INFO, self :: LOG);
		} catch (Exception $e) {
			JLog :: add('Error removing subscription (template: ' . $templateId . ', notification service: ' . $notificationService . ', query: ' . $queryId . ', result: ' . $resultId . ', alert mode: ' . $alertMode . ', subscriber: ' . $subscriber . '): ' . $e -> getMessage(), JLog :: ERROR, self :: LOG);
		}
	}

	private function getAlertModeAndSubscriber($alertMode, $batchPeriod, $user) {
		switch($alertMode) {
		case 'Atom':
			$subscriber = $this -> atomUrn;
			break;
		case 'JDBC':
			$subscriber = $this -> jdbcUri . '&table=' . urlencode($this -> databasePrefix . 'openaire_alerts') . '&username=' . urlencode($user -> get('username')) . '&time=' . urlencode('$time') . '&title=' . urlencode('$title') . '&message=' . urlencode('$message') . '&link=' . urlencode('$link');
			break;
		case 'Joomla!':
			$subscriber = $this -> jdbcUri . '&tablePrefix=' . urlencode($this -> databasePrefix) . '&category=' . urlencode($this -> newsCategory) . '&userId=' . urlencode($this -> newsUser);
			break;
		case 'SMTP':
			$subscriber = 'mailto:' . $user -> get('email');
			break;
		case 'twitter':
			$subscriber = 'data:accessToken=' . urlencode($this -> twitterAccessToken) . '&accessTokenSecret=' . urlencode($this -> twitterAccessTokenSecret);
			break;
		}
		if (($batchPeriod !== 0) && ($batchPeriod !== '0')) { // convert alert mode to batch alert mode
			$alertMode = 'Batch ' . $alertMode;
			$subscriber = 'batch:' . $subscriber . '#' . $batchPeriod;
		}
		return array($alertMode, $subscriber);
	}
	
	private function getAlertModeNameAndBatchPeriod($alertMode, $subscriberUri) {
		if ((strpos($alertMode, 'Batch ') === 0) && (strpos($subscriberUri, 'batch:') === 0)) { // alert mode is a batch alert mode
			$alertMode = substr($alertMode, strlen('Batch ')); // ommit 'Batch ' to get alert mode
			$batchPeriod = substr($subscriberUri, strpos($subscriberUri, '#') + 1); // find batch period
			switch ($batchPeriod) {
			case 30 * 24 * 60:
				$batchPeriod = 'monthly';
				break;
			case 15 * 24 * 60:
				$batchPeriod = 'bi-monthly';
				break;
			case 7 * 24 * 60:
				$batchPeriod = 'weekly';
				break;
			case 24 * 60:
				$batchPeriod = 'daily';
				break;
			case 0: // batch period is either zero or null; make it non-batch
			case '0':
			case NULL:
				$batchPeriod = 'as it happens';
				break;
			default:
				$batchPeriod = 'every ' . $batchPeriod . ' minute(s)';
			}
		} else // alert mode is not a batch alert mode
			$batchPeriod = 'as it happens';
		$query = $this -> db -> getQuery(TRUE);
		$query -> select('name');
		$query -> from('#__openaire_alert_modes');
		$query -> where('id = ' . $this -> db -> quote($alertMode));
		$this -> db -> setQuery($query);
		$alertModeName = $this -> db -> loadResult();
		if ($alertModeName === NULL)
			throw new Exception($this -> db -> getErrorMsg() . ' (' . $this -> db -> getErrorNum() . ')');
		return array($alertModeName, $batchPeriod);
	}
	
	private function getFullTopicName($templateId, $notificationService, $queryId, $resultId) {
		$query = $this -> db -> getQuery(TRUE);
		$query -> select('parent, name');
		$query -> from('#__openaire_topic_hierarchy');
		$query -> where('templateId = ' . $this -> db -> quote($templateId));
		$query -> where('notificationService = ' . $this -> db -> quote($notificationService));
		$query -> where('queryId = ' . $this -> db -> quote($queryId));
		$query -> where('resultId = ' . $this -> db -> quote($resultId));
		$this -> db -> setQuery($query);
		$topic = $this -> db -> loadObject();
		if ($topic === NULL)
			throw new Exception($this -> db -> getErrorMsg() . ' (' . $this -> db -> getErrorNum() . ')');
		return ($topic -> parent == NULL) ? $topic -> name : ($this -> getTopicNameById($topic -> parent) . ' ' . $topic -> name);
	}
	
	private function getTopicNameById($id) {
		$query = $this -> db -> getQuery(TRUE);
		$query -> select('parent, name');
		$query -> from('#__openaire_topic_hierarchy');
		$query -> where('id = ' . intval($id));
		$this -> db -> setQuery($query);
		$topic = $this -> db -> loadObject();		
		if ($topic === NULL)
			throw new Exception($this -> db -> getErrorMsg() . ' (' . $this -> db -> getErrorNum() . ')');
		return ($topic -> parent == NULL) ? $topic -> name : ($this -> getTopicNameById($topic -> parent) . ' ' . $topic -> name);
	}
}