/*  PAT: Persistent Applications Toolkit (patsystem.sf.net)
 *  Copyright (C) 2004, 2005  Tomasz Nazar, nthx at irc dot pl
 *
 *  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 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  Full version of the license is /docs/LICENSE.txt
 */
package org.nthx.pat;


import org.apache.log4j.Logger;
import org.jboss.aop.joinpoint.Invocation;
import org.jboss.aop.joinpoint.MethodInvocation;
import org.nthx.util.jbossaop.DefaultInterceptorImpl;


/** An aspect for intercepting every transacted method of system. 
 *  That's the main feature of PAT: provide automated transactions on demand.
 *  <p>Demand is specified by providing: 'pat.transaction' metadata in your
 *  code.
 * 
 *  @see GenericCommand
 *
 *  @version $Id: CommandInterceptor.java 3725 2005-06-09 23:57:03Z nthx $
 *  @author nthx@users.sourceforge.net
 */
public class CommandInterceptor
       extends DefaultInterceptorImpl
{
    private static Logger log = Logger.getLogger("pat");

    public Object invoke(Invocation invocation)
    throws Throwable
    {
        if (Pat.getInstance().isInNoCommandsMode())
            return invocation.invokeNext();

        if (Pat.getInstance().beforeRootConstructor()) 
        {
            return invocation.invokeNext();
        }


        MethodInvocation mi = (MethodInvocation) invocation;

        GenericCommand genericCommand = new GenericCommand(
                invocation.getTargetObject(),
                mi.getMethod(),
                mi.getArguments()
        );

        return Pat.getInstance().executeCommand(genericCommand);

        /* This is list place for future optimization:
         * We might want not to invoke logic from 'command', because it always
         * uses reflection.
         * Instead we might just 'save' command without invoking it, and
         * "proceed" with code - which equals in-command logic anyway.
         */
    }
}