<?php
/**
 * Database selector class
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 Core 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 DatabaseConnection extends BaseMiddleware implements DatabaseConnector, Registerable {
	/**
	 * Array for connection data
	 */
	private $connectData = array(
		'login'	=> '',
		'pass'	=> '',
		'dbase'	=> '',
		'host'	=> ''
	);

	// The real database layer
	private $dbLayer = null;

	// An instance of this class
	private static $thisInstance = null;

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

	// Create new database connection layer
	public final static function createDatabaseConnection (DebugMiddleware $debugInstance, DatabaseFrontendInterface $dbLayer) {
		// Get instance
		$dbInstance = new DatabaseConnection();

		// Set debug output handler
		$dbInstance->setDebugInstance($debugInstance);

		// Set database layer
		$dbInstance->setDatabaseLayer($dbLayer);

		// Set db instance
		self::$thisInstance = $dbInstance;

		// Return instance
		return $dbInstance;
	}

	// Get an instance of this class
	public final static function getInstance () {
		return self::$thisInstance;
	}

	// Public setter for database connection
	public final function setConnectionData ($login, $pass, $dbase, $host='localhost') {
		// Transfer connection data
		$this->connectData['login'] = (string) $login;
		$this->connectData['pass']  = (string) $pass;
		$this->connectData['dbase'] = (string) $dbase;
		$this->connectData['host']  = (string) $host;
	}

	/**
	 * Getter for connection data
	 *
	 * @return	$connectData	Connection data stored with this clas
	 */
	public final function getConnectionData () {
		return $this->connectData;
	}

	/**
	 * Setter for the real database layer
	 * @param	$dbLayer	An instance of the real database layer
	 * @return	void
	 */
	public final function setDatabaseLayer (DatabaseFrontendInterface $dbLayer) {
		$this->dbLayer = $dbLayer;
	}

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

	/**
	 * Runs a 'select' statement on the database layer with given table name
	 * and criteria. If this doesn't fail the result will be returned
	 *
	 * @param	$tableName			Name of the 'table' we shall query
	 * @param	$criteriaInstance	An instance of a Criteria class
	 * @return	$result				The result as an array
	 */
	public function doSelectByTableCriteria ($tableName, Criteria $criteriaInstance) {
		// Connect to the database
		$this->dbLayer->connectToDatabase();

		// Get result from query
		$result = $this->dbLayer->querySelect('array', $tableName, $criteriaInstance);

		// Return the result
		return $result;
	}

	/**
	 * Getter for last exception
	 *
	 * @return	$exceptionInstance	Last thrown exception
	 */
	public final function getLastException () {
		$exceptionInstance = $this->dbLayer->getLastException();
		return $exceptionInstance;
	}

	/**
	 * 'Inserts' a data set instance into a local file database folder
	 *
	 * @param	$dataSetInstance	A storeable data set
	 * @return	void
	 */
	public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
		// Connect to the database
		$this->dbLayer->connectToDatabase();

		// Ask the database layer
		$this->dbLayer->queryInsertDataSet($dataSetInstance);
	}

	/**
	 * 'Updates' a data set instance with a database layer
	 *
	 * @param	$dataSetInstance	A storeable data set
	 * @return	void
	 */
	public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
		// Connect to the database
		$this->dbLayer->connectToDatabase();

		// Ask the database layer
		$this->dbLayer->queryUpdateDataSet($dataSetInstance);
	}

	/**
	 * Getter for primary key column of specified table name
	 *
	 * @param	$tableName		Name of table we need the primary key column from
	 * @return	$primaryKey		Primary key column of requested table
	 */
	public function getPrimaryKeyOfTable ($tableName) {
		// Connect to the database
		$this->dbLayer->connectToDatabase();

		// Ask the database layer
		$primaryKey = $this->dbLayer->getPrimaryKeyOfTable($tableName);

		// Return the value
		return $primaryKey;
	}
}

// [EOF]
?>