<?php
/**
 * A database wrapper for peer state lookups
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009, 2010 Hub Developer Team
 * @license		GNU GPL 3.0 or any newer version
 * @link		http://www.ship-simu.org
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
class PeerStateLookupDatabaseWrapper extends BaseDatabaseWrapper {
	// Exception constants
	const EXCEPTION_PEER_ALREADY_REGISTERED = 0x300;

	// Constants for database table names
	const DB_TABLE_PEER_LOOKUP = 'peer_states';

	// Constants for database column names
	const DB_COLUMN_PEER_IP         = 'peer_ip';
	const DB_COLUMN_PEER_PORT       = 'peer_port';
	const DB_COLUMN_PEER_SESSION_ID = 'peer_session_id';

	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);
	}

	/**
	 * Creates an instance of this database wrapper by a provided user class
	 *
	 * @return	$wrapperInstance	An instance of the created wrapper class
	 */
	public final static function createPeerStateLookupDatabaseWrapper () {
		// Get a new instance
		$wrapperInstance = new PeerStateLookupDatabaseWrapper();

		// Set (primary!) table name
		$wrapperInstance->setTableName(self::DB_TABLE_PEER_LOOKUP);

		// Return the instance
		return $wrapperInstance;
	}

	/**
	 * Getter for index key
	 *
	 * @return	$indexKey	Index key
	 */
	public final function getIndexKey () {
		return $this->getDatabaseInstance()->getIndexKey();
	}

	/**
	 * Checks wether given 'sender' is a new peer
	 *
	 * @param	$packageData	Raw package data
	 * @return	$isNewPeer		Wether 'sender' is a new peer to this node
	 */
	public function isSenderNewPeer (array $packageData) {
		// Is always new peer by default
		$isNewPeer = true;

		// Remove session id > IP:port
		$ipPort = HubTools::resolveSessionId($packageData[NetworkPackage::INDEX_PACKAGE_SENDER]);

		// Is it not invalid:invalid?
		if ($ipPort != 'invalid:invalid') {
			// Get a search criteria instance
			$searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');

			// Add 'sender' as the peer's IP address
			$searchInstance->addCriteria(self::DB_COLUMN_PEER_IP, $ipPort);
			$searchInstance->setLimit(1);

			// Count the query
			$entries = $this->doSelectCountByCriteria($searchInstance);

			// Is it there?
			$isNewPeer = ($entries === 0);
		} // END - if

		// Return the result
		return $isNewPeer;
	}

	/**
	 * Registers a new peer with given package data. We use the session id from it.
	 *
	 * @param	$packageData		Raw package data
	 * @param	$socketResource		A valid socket resource
	 * @return	void
	 * @throws	PeerAlreadyRegisteredException	If a peer is already registered
	 * @throws	InvalidSocketException	If the socket resource was invalid
	 */
	public function registerPeerByPackageData (array $packageData, $socketResource) {
		// Make sure only new peers can be registered with package data
		if (!$this->isSenderNewPeer($packageData)) {
			// Throw an exception because this should normally not happen
			throw new PeerAlreadyRegisteredException(array($this, $packageData), self::EXCEPTION_PEER_ALREADY_REGISTERED);
		} // END - if

		// Generate a dataset instance
		$dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_PEER_LOOKUP));

		// Session ids must be unique
		$dataSetInstance->setUniqueKey(self::DB_COLUMN_PEER_SESSION_ID);

		// Add session id
		$dataSetInstance->addCriteria(self::DB_COLUMN_PEER_SESSION_ID, $packageData[NetworkPackage::INDEX_PACKAGE_SENDER]);

		// Get peer name
		if (!socket_getpeername($socketResource, $peerName, $peerPort)) {
			// Get last error
			$lastError = socket_last_error($socketResource);

			// Doesn't work!
			throw new InvalidSocketException(array($this, gettype($socketResource), $lastError, socket_strerror($lastError)), BaseListener::EXCEPTION_INVALID_SOCKET);
		} // END - if

		// Add ip address and port
		$dataSetInstance->addCriteria(self::DB_COLUMN_PEER_IP  , $peerName);
		$dataSetInstance->addCriteria(self::DB_COLUMN_PEER_PORT, $peerPort);

		// "Insert" the data set
		$this->getDatabaseInstance()->queryInsertDataSet($dataSetInstance);
	}

	/**
	 * Purges old entries of given socket resource. We use the IP address from that resource.
	 *
	 * @param	$socketResource		A valid socket resource
	 * @return	void
	 * @throws	InvalidSocketException	If the socket resource was invalid
	 */
	public function purgeOldEntriesBySocketResource ($socketResource) {
		// Get peer name
		if (!socket_getpeername($socketResource, $peerName, $peerPort)) {
			// Get last error
			$lastError = socket_last_error($socketResource);

			// Doesn't work!
			throw new InvalidSocketException(array($this, gettype($socketResource), $lastError, socket_strerror($lastError)), BaseListener::EXCEPTION_INVALID_SOCKET);
		} // END - if
	}
}

// [EOF]
?>