<?php
/**
 * A database wrapper for the User class
 *
 * @see			DatabaseFrontendInterface - An interface for database frontends (front-end to the application)
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright(c) 2007, 2008 Roland Haeder, this is free software
 * @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 UserDatabaseWrapper extends BaseDatabaseWrapper {
	/**
	 * Cache instance
	 */
	private $cacheInstance = null;

	// Constants for exceptions
	const EXCEPTION_CLIENT_USERNAME_NOT_FOUND = 0xe00;

	// Constants for database columns
	const DB_COLUMN_USERNAME = "username";

	// Constants for database table names
	const DB_TABLE_USER = "user";

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

		// Set part description
		$this->setObjectDescription("Database wrapper for user objects");

		// Create unique ID number
		$this->createUniqueID();
	}

	/**
	 * Creates an instance of this database wrapper by a provided user class
	 *
	 * @return	$wrapperInstance	An instance of the created wrapper class
	 * @throws	WrapperUserNameNotFoundException	If the supplied username
	 *												does not exist
	 */
	public final static function createUserDatabaseWrapper () {
		// Get a new instance
		$wrapperInstance = new UserDatabaseWrapper();

		// Initialize the cache instance
		$wrapperInstance->initCacheInstance();

		// Return the instance
		return $wrapperInstance;
	}

	/**
	 * Initializes the cache instance with a new object
	 *
	 * @return	void
	 */
	protected function initCacheInstance () {
		// Set the new instance
		$this->cacheInstance = CacheFactory::getFactory()->createConfiguredCache();
	}

	/**
	 * Do a "select" query on the user table with the given search criteria and
	 * store it in cache for later usage
	 *
	 * @param	$criteriaInstance	An instance of a Criteria class
	 * @return	$resultInstance		An instance of a database result class
	 */
	public function doSelectByCriteria (Criteria $criteriaInstance) {
		// First get a key suitable for our cache and extend it with this class name
		$cacheKey = sprintf("%s@%s",
			$this->__toString(),
			$criteriaInstance->getCacheKey()
		);

		// Does this key exists in cache?
		if ($this->cacheInstance->offsetExists($cacheKey)) {
			// Then use this result
			$result = $cacheInstance->offsetGet($cacheKey);
		} else {
			// Now it's time to ask the database layer for this select statement
			$result = $this->getDatabaseInstance()->doSelectByTableCriteria(self::DB_TABLE_USER, $criteriaInstance);

			// Cache the result
			$this->cacheInstance->offsetSet($cacheKey, $result);
		}

		// Create an instance of a DatabaseResult class with the given result
		$resultInstance = DatabaseResult::createDatabaseResult($result);

		// And return the instance
		return $resultInstance;
	}
}

// [EOF]
?>