/**
 * 
 */
package de.intevation.gnv.geobackend.base.connectionpool;

import java.util.Properties;

import org.apache.log4j.Logger;

import de.intevation.gnv.geobackend.sde.connectionpool.ArcSDEConnectionPool;

/**
 * Factoryimplementation for the Interface ConnectionPool.
 * This factory delivers Instances of the Interface ConnectionPool.
 * @author Tim Englich <tim.englich@intevation.de>
 */
public class ConnectionPoolFactory {

	
	/**
     * the logger, used to log exceptions and additonaly information
     */
    private static Logger log = Logger.getLogger(ConnectionPoolFactory.class);
	
    
    /**
     * The singleton Instance of this Factory.
     */
	private static ConnectionPoolFactory instance = null;
	
	/**
	 * The ConnectionPool providing the Connections to the DatabaseBackends
	 */
	private ConnectionPool connectionPool = null;
	
	/**
	 * Basic-Constructor of this Class
	 */
	private ConnectionPoolFactory() {
		super();
	}
	
	
	/**
	 * This Method provides an singleton Instance of this Class.
	 * @return an singleton Instance of this Class
	 */
	public static ConnectionPoolFactory getInstance(){
		if (instance == null){
			instance = new ConnectionPoolFactory();
		}
		return instance;
	}
	
	
	/**
	 * Getting the ConnectionPool
	 * @return the ConnectionPool
	 */
	public ConnectionPool getConnectionPool(){
		return this.connectionPool;
	}
	
	
	/**
	 * Initializes the ConnectionPool.
	 * Should only be called once on system startup
	 * @param properties the Properties for the Individual Configuration of the ConnectionPool
	 */
	public void initializeConnectionPool(Properties properties){
		log.debug("ConnectionPoolFactory.initializeConnectionPool");
		if (this.connectionPool == null){
			//TODO: Hier k�nnte anhand eines Flags die Instanz des Connectionpools umgeschaltet werden.
			this.connectionPool = new ArcSDEConnectionPool();
			this.connectionPool.initialize(properties);
		}else{
			log.warn("ConnectionPool already initialized");
		}	
	}
	
	/**
	 * Checks if the ConnectionPool has already been initialized.
	 * @return true if the ConnectionPool is initialized.
	 */
	public boolean isInitialized(){
		return this.connectionPool != null;
	}
}