/* ===========================================================
 * JDBMonitor : a flexiable JDBC Monitor for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2006-2006, by yang zhongke
 *
 * Project Info:  http://www.cownew.com
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ---------------
 * DBDriver.java
 * ---------------
 * (C) Copyright 2006-2006, by yang zhongke
 *
 * Original Author:  yang zhongke;
 *
 * Changes
 * -------
 *
 */
package com.cownew.JDBMonitor.jdbc;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.DriverPropertyInfo;
import java.sql.SQLException;
import java.util.List;
import java.util.Properties;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.cownew.JDBMonitor.common.CommonUtils;
import com.cownew.JDBMonitor.common.ConfigFileInfo;
import com.cownew.JDBMonitor.common.ConfigFileReader;
import com.cownew.JDBMonitor.common.DBListenerInfo;
import com.cownew.JDBMonitor.common.InstanceUtils;

/**
 * the JDBC driver of the DBMonitor
 * @author yang zhongke
 */
public class DBDriver implements java.sql.Driver
{    
    public synchronized Connection connect(String url, Properties info)
	throws SQLException {
    	if(!acceptsURL(url))
    	{
    		throw new SQLException("Illegal URL Format:"+url);
    	}
    	
    	Matcher match = getURLMatcher(url);
    	match.matches();
    	match.group();
    	String configFile = match.group(1);
    	String realUrl = match.group(2);  
    	
    	ConfigFileInfo configInfo = null;    	
    	
    	InputStream is = null;
    	try
    	{
    		//get the configFileInfo from configFile
    		if(ConfigFileReader.isRealFilePath(configFile))
    		{
    			is = new FileInputStream(configFile);
    		}
    		else
    		{
    	    	is = this.getClass().getResourceAsStream(configFile);
    		}
    		configInfo = ConfigFileReader.getConfigFileInfo(is);
    		
    		//register the necessary JDBCDriver
    		//generally, it's the real JdbcDriver of the database to be logged
    		registerRealJdbcDriver(configInfo);
    	} catch (FileNotFoundException e)
		{
			throw JdbcUtils.toSQLException(e);
		}
    	finally
    	{
    		InstanceUtils.closeInStream(is);
    	}
    	
    	//get the real database connection of the database to be logged
    	Connection cn = DriverManager.getConnection(realUrl, info);
    	
    	//if the monitor is not active,return the real database connection
    	if(!configInfo.isActive())
    	{
    		return cn;
    	}
    	
    	List lisList = configInfo.getListenerInfoList();
    	DBListenerInfo[] dbListenerInfos = new DBListenerInfo[lisList.size()];
    	for(int i=0,n=lisList.size();i<n;i++)
    	{
    		DBListenerInfo lisInfo = (DBListenerInfo) lisList.get(i);
    		dbListenerInfos[i] = lisInfo;
    	}    	
		return new DBConnection(cn,dbListenerInfos);    	
    }


    /**
     * get the regular expression matcher of the jdbcurl 
     * @param url
     * @return
     */
	private Matcher getURLMatcher(String url)
	{
		Pattern pattern = Pattern.compile("listenerconfig=(.+):url=(.+)"); 
    	Matcher match = pattern.matcher(url);
		return match;
	}   
    
    
    private synchronized void registerRealJdbcDriver(ConfigFileInfo configInfo)
			throws SQLException
	{
		List list = configInfo.getRealJdbcDriverList();
		for (int i = 0, n = list.size(); i < n; i++)
		{
			try
			{
				Class.forName(list.get(i).toString());
			} catch (ClassNotFoundException e)
			{
				throw JdbcUtils.toSQLException(e);
			}
		}

	}


	public boolean acceptsURL(String url) throws SQLException {
		Matcher m = getURLMatcher(url);
	    return m.matches();
    }
    
    public DriverPropertyInfo[] getPropertyInfo(String url, Properties info)
			throws SQLException
	{
		DriverPropertyInfo[] props = new DriverPropertyInfo[1];
		props[0] = new DriverPropertyInfo("author", "Yang Zhongke");
		return props;
	}
    
    public int getMajorVersion() {
	return 1;
    }
    
    public int getMinorVersion() {
	return 0;
    }
    
    public boolean jdbcCompliant() {
	return true;
    }   
   
    
    static
	{
		try
		{
			DriverManager.registerDriver(new DBDriver());
		} catch (Exception e)
		{
			throw CommonUtils.toRuntimeException(e);
		}
	}
}