/*
 Wotonomy: OpenStep design patterns for pure Java applications.
 Copyright (C) 2001 Michael Powers

 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.

 This library 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
 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, see http://www.gnu.org
 */
package net.wotonomy.jdbcadaptor;

import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;

import net.wotonomy.access.EOAdaptor;
import net.wotonomy.access.EOAdaptorChannel;
import net.wotonomy.access.EOAdaptorContext;
import net.wotonomy.foundation.NSDictionary;

/**
 * Concrete implementation of EOAdaptorContext for use with JDBC.
 *
 * @author ezamudio@nasoft.com
 * @author $Author: cgruber $
 * @version $Revision: 903 $
 */
public class JDBCContext extends EOAdaptorContext {

	protected Connection _jdbcConnection;

	/**
	 * Creates a new instance.
	 * 
	 * @param adaptor The adaptor this context belongs to.
	 */
	public JDBCContext(EOAdaptor adaptor) {
		super(adaptor);
	}

	public void connect() throws JDBCAdaptorException {
		try {
			if (_jdbcConnection != null && !_jdbcConnection.isClosed())
				throw new JDBCAdaptorException("Attempt to connect when already connected.", null);
			Class.forName(((JDBCAdaptor) adaptor()).driverName());
			NSDictionary<String, Object> connectionDictionary = adaptor().connectionDictionary();
			String url = (String) connectionDictionary.objectForKey("URL");
			Driver driver = DriverManager.getDriver(url);
			java.util.Properties props = new java.util.Properties();
			if (connectionDictionary.containsKey("username"))
				props.setProperty("user", (String) connectionDictionary.objectForKey("username"));
			if (connectionDictionary.containsKey("password"))
				props.setProperty("password", (String) connectionDictionary.objectForKey("password"));
			_jdbcConnection = driver.connect(url, props);
			_jdbcConnection.setAutoCommit(false);
		} catch (SQLException ex) {
			throw new JDBCAdaptorException("Cannot connect to database", ex);
		} catch (ClassNotFoundException ex) {
			throw new JDBCAdaptorException("Cannot find JDBC driver " + ex.getMessage(), null);
		}
	}

	public void disconnect() throws JDBCAdaptorException {
		if (_jdbcConnection != null) {
			try {
				_jdbcConnection.close();
				_jdbcConnection = null;
				transactionDidRollback();
			} catch (SQLException ex) {
				throw new JDBCAdaptorException("Trying to close connection.", ex);
			}
		}
	}

	public Connection connection() {
		return _jdbcConnection;
	}

	/*
	 * Begins a transaction. Actually it does nothing because it's not necessary.
	 * 
	 * @see net.wotonomy.access.EOAdaptorContext#beginTransaction()
	 */
	public void beginTransaction() {
		if (hasOpenTransaction())
			throw new JDBCAdaptorException("Cannot nest transactions.", null);
		transactionDidBegin();
	}

	/*
	 * Commits a transaction.
	 * 
	 * @see net.wotonomy.access.EOAdaptorContext#commitTransaction()
	 */
	public void commitTransaction() {
		try {
			_jdbcConnection.commit();
			transactionDidCommit();
		} catch (SQLException ex) {
			throw new JDBCAdaptorException("Cannot commit.", ex);
		}
	}

	/*
	 * Rolls back a transacion.
	 * 
	 * @see net.wotonomy.access.EOAdaptorContext#rollbackTransaction()
	 */
	public void rollbackTransaction() {
		try {
			_jdbcConnection.rollback();
			transactionDidRollback();
		} catch (SQLException ex) {
			throw new JDBCAdaptorException("Cannot commit.", ex);
		}
	}

	/*
	 * Creates a JDBCChannel instance.
	 * 
	 * @see net.wotonomy.access.EOAdaptorContext#createAdaptorChannel()
	 */
	public EOAdaptorChannel createAdaptorChannel() {
		JDBCChannel channel = new JDBCChannel(this);
		_channels.addObject(channel);
		return channel;
	}

	/*
	 * I don't know what to do here. Throw something, maybe?
	 * 
	 * @see net.wotonomy.access.EOAdaptorContext#handleDroppedConnection()
	 */
	public void handleDroppedConnection() {
		// TODO Auto-generated method stub

	}

}
/*
 * $Log$ Revision 1.2 2006/02/18 22:59:22 cgruber make it compile with maven
 * dependencies and add a cvsignore.
 *
 * Revision 1.1 2006/02/16 13:22:23 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.1 2003/08/13 20:13:33 chochos concrete implementation of
 * EOAdaptorContext for use with JDBC. This is the class that holds the physical
 * connection to the database.
 *
 */