package fr.univ_tln.bruno.mycompany.jdbc.pool;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.LinkedList;
import java.util.Queue;

/**
 * The Class DatabaseManager.
 */
public class DatabaseManager {

	/** The Constant freeConnections. */
	private static final Queue<Connection> freeConnections = new LinkedList<Connection>();

	/** The Constant numberOfInitialConnections. */
	private static final int numberOfInitialConnections = 5;

	/** The Constant password. */
	private static final String password = System
			.getProperty("MyCompany.database.password");

	/** The Constant url. */
	private static final String url = System
			.getProperty("MyCompany.database.url");

	/** The Constant user. */
	private static final String user = System
			.getProperty("MyCompany.database.user");

	static {
		for (int i = 0; i < numberOfInitialConnections; i++) {
			try {
				freeConnections.add(DriverManager.getConnection(url, user,
						password));
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}

	/**
	 * Gets the connection.
	 * 
	 * @return the connection
	 * 
	 * @throws SQLException
	 *             the SQL exception
	 */
	public static synchronized Connection getConnection() throws SQLException {
		Connection connection = null;
		if (freeConnections.isEmpty()) {
			connection = DriverManager.getConnection(url, user, password);
		} else {
			connection = freeConnections.remove();
		}
		return connection;
	}

	/**
	 * Release connection.
	 * 
	 * @param connection
	 *            the connection
	 */
	public static synchronized void releaseConnection(Connection connection) {
		if (freeConnections.size() < numberOfInitialConnections) {
			freeConnections.add(connection);
		} else {
			try {
				connection.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
}