<?php
/**
 * This class contains static helper functions for our hub
 *
 * @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 HubTools extends BaseFrameworkSystem {
	// Constants for exceptions
	const EXCEPTION_SESSION_ID_IS_INVALID = 0x200;

	/**
	 * Cache for session ids
	 */
	private $sessionIdCache = array();

	/**
	 * Length for session id (should be 32+salt_length
	 */
	private $sessionIdLength = 0;

	/**
	 * Self instance
	 */
	private static $selfInstance = null;

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

		// Init salt length
		$this->sessionIdLength = 32 + $this->getConfigInstance()->getConfigEntry('salt_length');
	}

	/**
	 * Singleton getter for self instance
	 *
	 * @retuen	$selfInstance	An instance of this class
	 */
	public final static function getInstance () {
		// Is the instance set
		if (is_null(self::$selfInstance)) {
			// Then set it
			self::$selfInstance = new HubTools();
		} // END - if

		// Return own instance
		return self::$selfInstance;
	}

	/**
	 * Getter for session id length
	 *
	 * @return	$sessionIdLength	Length of session ids
	 */
	protected final function getSessionIdLength () {
		return $this->sessionIdLength;
	}

	/**
	 * Resolves a session id into an ip:port combination
	 *
	 * @param	$sessionId	A valid session id
	 * @return	$recipient	Recipient as ip:port combination
	 */
	protected function resolveIpPortBySessionId ($sessionId) {
		// Get a wrapper instance
		$wrapperInstance = DatabaseWrapperFactory::createWrapperByConfiguredName('node_list_db_wrapper_class');

		// And ask it for the session id
		$recipient = $wrapperInstance->resolveIpPortBySessionId($sessionId);

		// Return result
		return $recipient;
	}

	/**
	 * Resolves given session id into an ip:port combination, if ip:port is set, it won't be translated
	 *
	 * @param	$sessionId	Session id or ip:port combination
	 * @return	$recipient	Recipient as ip:port combination
	 * @throws	InvalidSessionIdException	If the provided session id is invalid (and no ip:port combination)
	 */
	public static function resolveSessionId ($sessionId) {
		// Get an own instance
		$selfInstance = self::getInstance();

		// Default is direct ip:port
		$recipient = $sessionId;

		// Does it match a direct ip:port? (hint: see www.regexlib.com for the regular expression)
		if (!preg_match('/((?:2[0-5]{2}|1\d{2}|[1-9]\d|[1-9])\.(?:(?:2[0-5]{2}|1\d{2}|[1-9]\d|\d)\.){2}(?:2[0-5]{2}|1\d{2}|[1-9]\d|\d)):(\d|[1-9]\d|[1-9]\d{2,3}|[1-5]\d{4}|6[0-4]\d{3}|654\d{2}|655[0-2]\d|6553[0-5])/', $sessionId)) {
			// Is it in cache?
			if (isset($selfInstance->sessionIdCache[$sessionId])) {
				// Debug message
				$selfInstance->debugOutput('HUB-TOOLS: Using entry from sessionIdCache[] array.');

				// Then use it
				$recipient = $selfInstance->sessionIdCache[$sessionId];
			} elseif (!preg_match('/([a-f0-9]{' . $selfInstance->getSessionIdLength() . '})/', $sessionId)) {
				// Invalid session id
				throw new InvalidSessionIdException($sessionId, self::EXCEPTION_SESSION_ID_IS_INVALID);
			} else {
				// Debug message
				$selfInstance->debugOutput('HUB-TOOLS: Using internal resolver.');

				// Resolve it here
				$recipient = $selfInstance->resolveIpPortBySessionId($sessionId);
			}
		} // END - if

		// Output message
		$selfInstance->debugOutput('HUB-TOOLS: Session id ' . $sessionId . ' resolved to ' . $recipient);

		// Return it
		return $recipient;
	}
}

// [EOF]
?>