/**

 * SQL-DK

 * Copyright © 2015 František Kučera (frantovo.cz)

 *

 * 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, version 3 of the License.

 *

 * 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/>.

 */

package info.globalcode.sql.dk.configuration;

import info.globalcode.sql.dk.*;

import static info.globalcode.sql.dk.DatabaseConnection.JDBC_PROPERTY_USER;

import static info.globalcode.sql.dk.DatabaseConnection.JDBC_PROPERTY_PASSWORD;

import java.sql.Connection;

import java.sql.Driver;

import java.sql.DriverManager;

import java.sql.SQLException;

import java.util.logging.Level;

import java.util.logging.Logger;

import javax.xml.bind.JAXBContext;

import javax.xml.bind.Unmarshaller;

/**

 * Configuration loader – deserializes Configuration from the XML file.

 *

 * @author Ing. František Kučera (frantovo.cz)

 */

public class Loader {

	private static final Logger log = Logger.getLogger(Loader.class.getName());

	public Configuration loadConfiguration() throws ConfigurationException {

		try {

			JAXBContext jaxb = JAXBContext.newInstance(Configuration.class.getPackage().getName(), Configuration.class.getClassLoader());

			Unmarshaller u = jaxb.createUnmarshaller();

			return (Configuration) u.unmarshal(Constants.CONFIG_FILE);

		} catch (Exception e) {

			throw new ConfigurationException("Unable to load configuration from " + Constants.CONFIG_FILE, e);

		}

	}

	/**

	 * JDBC connection should not be used directly in SQL-DK.

	 *

	 * @see DatabaseDefinition#connect(info.globalcode.sql.dk.configuration.Properties)

	 * @param properties

	 * @param databaseDefinition

	 * @return

	 * @throws java.sql.SQLException

	 */

	public static Connection jdbcConnect(DatabaseDefinition databaseDefinition, Properties properties) throws SQLException {

		synchronized (properties) {

			/**

			 * Avoid rewriting the properties. Usually, the connection is created only once, but

			 * with --test-connection and with SQL-DK JDBC driver, it might be reused.

			 */

			properties = properties.clone();

		}

		if (properties.hasProperty(JDBC_PROPERTY_PASSWORD)) {

			log.log(Level.WARNING, "Passing DB password as CLI parameter is insecure!");

		}

		Properties credentials = new Properties();

		credentials.add(new Property(JDBC_PROPERTY_USER, databaseDefinition.getUserName()));

		credentials.add(new Property(JDBC_PROPERTY_PASSWORD, databaseDefinition.getPassword()));

		credentials.setDefaults(databaseDefinition.getProperties());

		properties.setDefaults(credentials);

		java.util.Properties javaProperties = properties.getJavaProperties();

		String driverClassName = databaseDefinition.getDriver();

		final String url = databaseDefinition.getUrl();

		if (driverClassName == null) {

			log.log(Level.FINE, "Using DriverManager to create connection for „{0}“", url);

			return DriverManager.getConnection(url, javaProperties);

		} else {

			log.log(Level.FINE, "Using custom Driver „{0}“ to create connection for „{1}“", new Object[]{driverClassName, url});

			try {

				Class<Driver> driverClass = (Class<Driver>) Class.forName(driverClassName);

				Driver driver = driverClass.newInstance();

				Connection connection = driver.connect(url, javaProperties);

				if (connection == null) {

					log.log(Level.SEVERE, "Driver „{0}“ returend null → it does not accept the URL: „{1}“", new Object[]{driverClassName, url});

					throw new SQLException("Unable to connect: driver returned null.");

				} else {

					return connection;

				}

			} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | SQLException e) {

				throw new SQLException("Unable to connect usig specific driver: " + driverClassName, e);

			}

		}

	}

}