/**

 * Simple Database Client for Java

 *

 */

package org.homelinux.largo.sql.client;

import java.util.List;

import java.util.ArrayList;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.DatabaseMetaData;

import java.sql.ResultSet;

import java.sql.Statement;

import java.sql.SQLException;

import javax.naming.Context;

import javax.naming.NamingException;

import javax.naming.InitialContext;

import javax.sql.DataSource;

public class DBClient {

	private Connection connection;

	private DatabaseMetaData metadata;

	private Statement statement;

	private ResultSet resultset;

	private String driver, username, password;

	private String dbURL;

	/**

	 * Constructor to connect to a database with a specific driver

	 * and connection string

	 */

	public DBClient (String driver, String dbURL, String username, String password) throws ClassNotFoundException, SQLException {

		this.driver = driver;

		this.dbURL = dbURL;

		Class.forName (driver);

		connect (username, password);

	}

	/**

	 * Constructor to connect to a database with a specific driver

	 * and connection string

	 */

	public DBClient (String driver, String dbURL) throws ClassNotFoundException, SQLException {

		this (driver, dbURL, null, null);

	}

	/**

	 * Default Constructor to connect to my database

	 */

	public DBClient () throws ClassNotFoundException, SQLException {

		this ("org.apache.derby.jdbc.EmbeddedDriver", "jdbc:derby:clubstatistik", null, null);

	}

	/**

	 * Constructor to connect to a DataSource on an AppServer

	 */

	public DBClient (String jndiResource) throws NamingException, SQLException {

		Context ctx = new InitialContext ();

		DataSource ds = (DataSource) ctx.lookup (jndiResource);

		connection = ds.getConnection ();

		statement = connection.createStatement ();

	}

        protected void connect(String user, String pass) throws SQLException {

		assert (connection == null) : "CONNECT: Already connected";

		this.username = user;

		this.password = pass;

		connection = DriverManager.getConnection (dbURL, username, password);

		metadata = connection.getMetaData();

		statement = connection.createStatement ();

	}

	public void disconnect () throws SQLException {

		if (connection == null)

			throw new SQLException ("DISCONNECT: Not connected");

		else

			connection.close ();

	}

	public String getColumn (int pos) throws SQLException {

		return resultset.getString (pos);

	}

	public String getColumn (String name) throws SQLException {

		return resultset.getString (name);

	}

	public List<String> getTables() throws SQLException {

		List<String> list = new ArrayList<String>();

		resultset = metadata.getTables(null, null, "%", null);

		while (resultset.next()) {

			list.add(resultset.getString("TABLE_NAME"));

		}

		return list;

	}

	public List<String> getColumns(String table) throws SQLException {

		List<String> list = new ArrayList<String>();

		resultset = metadata.getColumns(null, null, table, null);

		while (resultset.next()) {

			list.add(resultset.getString("COLUMN_NAME"));

		}

		return list;

	}

	public Connection getConnection () {

		return connection;

	}

	public String getDbURL () {

		return dbURL;

	}

	public String getDriver () {

		return driver;

	}

	public String getPassword () {

		return password;

	}

	public String getUsername () {

		return username;

	}

	public boolean hasNext () throws SQLException {

		return resultset.next ();

	}

	public void query (String query) throws SQLException {

		resultset = statement.executeQuery (query);

	}

	/**

         * returns the number of updated rows

         */

	public int update (String update) throws SQLException {

		return statement.executeUpdate (update);

	}

	public void setConnection (Connection connection) {

		this.connection = connection;

	}

	public void setDbURL (String dbURL) {

		this.dbURL = dbURL;

	}

	public void setDriver (String driver) {

		this.driver = driver;

	}

	public void setPassword (String password) {

		this.password = password;

	}

	public void setUsername (String username) {

		this.username = username;

	}

}