<?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
	const EXCEPTION_CLIENT_USERNAME_NOT_FOUND = 0xe00;

	/**
	 * 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();

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

	/**
	 * Creates an instance of this database wrapper by a provided user class
	 *
	 * @param	$userInstance		An instance of a 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 (ManageableUser $userInstance) {
		// Get a new instance
		$wrapperInstance = new UserDatabaseWrapper();

		// Does the username exists?
		if (!$wrapperInstance->ifUserNameExists($userInstance->getUserName())) {
			// Throw an exception here
			throw new WrapperUserNameNotFoundException (array($wrapperInstance, $userInstance), self::EXCEPTION_CLIENT_USERNAME_NOT_FOUND);
		}

		// The user exists
		$wrapperInstance->partialStub("Add loading of full user details");

		// Return the instance
		return $wrapperInstance;
	}

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

	/**
	 * Checks wether the given username is already used
	 *
	 * @param	$userName	The username we shall look up
	 * @return	$exists		Wether the username exists
	 */
	public function ifUserNameExists ($userName) {
		// By default no entry exist
		$exists = false;

		// Does this entry exist?
		if ($this->cacheInstance->offsetExists($userName)) {
			// Then we have a user!
			$exists = true;
		} else {
			// Create a search criteria
			$criteriaInstance = ObjectFactory::createObjectByConfiguredName('search_criteria');

			// Add the username as a criteria and set limit to one entry
			$criteriaInstance->add(self::DB_USERNAME, $userName);
			$criteriaInstance->setLimit(1);

			// Get a search result
			$result = $this->doSelectByCriteria($criteriaInstance);

			// Search for it
			if ($result->next()) {
				// Get the result
				$this->cacheInstance->add($userName, $result->getResultArray());

				// Entry found, so all is fine
				$exists = true;
			}
		}

		// Return the result
		return $exists;
	}
}

// [EOF]
?>