/*******************************************************************************
 * Copyright (c) 2004 Actuate Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *  Actuate Corporation  - initial API and implementation
 *******************************************************************************/

package org.eclipse.birt.chart.log;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.logging.Level;
import java.util.logging.SimpleFormatter;
import java.util.logging.StreamHandler;

import org.eclipse.birt.chart.internal.log.JavaUtilLoggerImpl;
import org.eclipse.birt.core.framework.Platform;

/**
 * A centralized class to start use and manager loggers.
 * 
 * @see ILogger
 */
final public class Logger
{

	private static StreamHandler tracingHandler;

	/**
	 * Don't instanciate.
	 */
	private Logger( )
	{
	}

	/**
	 * Returns the logger by the given name.
	 * 
	 * @param name
	 * @return
	 */
	synchronized public static final ILogger getLogger( String name )
	{
		// TODO use java logger impl as default, later will use the extension
		// configuration.

		JavaUtilLoggerImpl chartLogger = new JavaUtilLoggerImpl( name );

		if ( name != null )
		{
			int idx = name.indexOf( "/" ); //$NON-NLS-1$

			if ( idx > 0 )
			{
				String pluginId = name.substring( 0, idx );
				boolean isDebugging = "true".equals( Platform.getDebugOption( pluginId + "/debug" ) ); //$NON-NLS-1$ //$NON-NLS-2$

				if ( isDebugging )
				{
					// Enable tracing.
					String value = Platform.getDebugOption( name );

					if ( "true".equals( value ) ) //$NON-NLS-1$
					{
						// setup the logger.
						java.util.logging.Logger javaLogger = chartLogger.getJavaLogger( );
						try
						{
							if ( javaLogger.getLevel( ).intValue( ) > Level.FINEST.intValue( ) )
							{
								javaLogger.setLevel( Level.FINEST );
							}
							javaLogger.removeHandler( getTracingHandler( ) );
							javaLogger.addHandler( getTracingHandler( ) );
						}
						catch ( SecurityException e )
						{
							e.printStackTrace( );
						}
					}
				}
			}
		}

		return chartLogger;
	}

	private static StreamHandler getTracingHandler( )
	{
		if ( tracingHandler == null )
		{
			tracingHandler = AccessController.doPrivileged( new PrivilegedAction<StreamHandler>( ) {

				public StreamHandler run( )
				{
					StreamHandler handler = new StreamHandler( System.out,
							new SimpleFormatter( ) );
					try
					{
						tracingHandler.setLevel( Level.ALL );
					}
					catch ( SecurityException e )
					{
						e.printStackTrace( );
					}
					return handler;
				}
			} );
		}
		return tracingHandler;
	}

}
