// $Header: /home/cvs/jakarta-jmeter/src/core/org/apache/jmeter/gui/action/ActionRouter.java,v 1.22 2004/02/22 19:37:06 sebb Exp $
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
*/

package org.apache.jmeter.gui.action;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.swing.SwingUtilities;

import org.apache.jmeter.exceptions.IllegalUserActionException;
import org.apache.jmeter.gui.GuiPackage;
import org.apache.jmeter.util.JMeterUtils;
import org.apache.jorphan.logging.LoggingManager;
import org.apache.jorphan.reflect.ClassFinder;
import org.apache.log.Logger;

/**
 * @author     Michael Stover
 * @version    $Revision: 1.22 $
 */
public final class ActionRouter implements ActionListener
{
    private Map commands = new HashMap();
    private static ActionRouter router;
    transient private static Logger log = LoggingManager.getLoggerForClass();
    private Map preActionListeners = new HashMap();
    private Map postActionListeners = new HashMap();

    private ActionRouter()
    {
    }

    public void actionPerformed(final ActionEvent e)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                performAction(e);
            }

        });
    }

    private void performAction(final ActionEvent e)
    {
        try
        {
            GuiPackage.getInstance().updateCurrentNode();
            Set commandObjects = (Set) commands.get(e.getActionCommand());
            Iterator iter = commandObjects.iterator();
            while (iter.hasNext())
            {
                try
                {
                    Command c = (Command) iter.next();
                    preActionPerformed(c.getClass(), e);
                    c.doAction(e);
                    postActionPerformed(c.getClass(), e);
                }
                catch(IllegalUserActionException err)
                {
                    JMeterUtils.reportErrorToUser(err.toString());
                }
                catch (Exception err)
                {
                    log.error("", err);
                }
            }
        }
        catch (NullPointerException er)
        {
            log.error("performAction("+e.getActionCommand()+") " + e.toString() + " caused", er);
            JMeterUtils.reportErrorToUser(
                "Sorry, this feature ("
                    + e.getActionCommand()
                    + ") not yet implemented");
        }
    }

    /**
     * To execute an action immediately in the current thread.
     * @param e the action to execute
     */
    public void doActionNow(ActionEvent e)
    {
        performAction(e);
    }

    public Set getAction(String actionName)
    {
        Set set = new HashSet();
        Set commandObjects = (Set) commands.get(actionName);
        Iterator iter = commandObjects.iterator();
        while (iter.hasNext())
        {
            try
            {
                set.add(iter.next());
            }
            catch (Exception err)
            {
                log.error("", err);
            }
        }
        return set;
    }

    public Command getAction(String actionName, Class actionClass)
    {
        Set commandObjects = (Set) commands.get(actionName);
        Iterator iter = commandObjects.iterator();
        while (iter.hasNext())
        {
            try
            {
                Command com = (Command) iter.next();
                if (com.getClass().equals(actionClass))
                {
                    return com;
                }
            }
            catch (Exception err)
            {
                log.error("", err);
            }
        }
        return null;
    }

    public Command getAction(String actionName, String className)
    {
        Set commandObjects = (Set) commands.get(actionName);
        Iterator iter = commandObjects.iterator();
        while (iter.hasNext())
        {
            try
            {
                Command com = (Command) iter.next();
                if (com.getClass().getName().equals(className))
                {
                    return com;
                }
            }
            catch (Exception err)
            {
                log.error("", err);
            }
        }
        return null;
    }

    /**
     * Allows an ActionListener to receive notification of a command
     * being executed prior to the actual execution of the command.
     * 
     * @param action    the Class of the command for which the listener will
     *                  notifications for. Class must extend
     *                  org.apache.jmeter.gui.action.Command.
     * @param listener  the ActionListener to receive the notifications
     */
    public void addPreActionListener(Class action, ActionListener listener)
    {
        if (action != null)
        {
            HashSet set = (HashSet) preActionListeners.get(action.getName());
            if (set == null)
            {
                set = new HashSet();
            }
            set.add(listener);
            preActionListeners.put(action.getName(), set);
        }
    }

    /**
     * Allows an ActionListener to be removed from receiving 
     * notifications of a command being executed prior to the actual 
     * execution of the command.
     * 
     * @param action    the Class of the command for which the listener will
     *                  notifications for. Class must extend
     *                  org.apache.jmeter.gui.action.Command.
     * @param listener  the ActionListener to receive the notifications
     */
    public void removePreActionListener(Class action, ActionListener listener)
    {
        if (action != null)
        {
            HashSet set = (HashSet) preActionListeners.get(action.getName());
            if (set != null)
            {
                set.remove(listener);
                preActionListeners.put(action.getName(), set);
            }
        }
    }

    /**
     * Allows an ActionListener to receive notification of a command
     * being executed after the command has executed.
     * 
     * @param action    the Class of the command for which the listener will
     *                  notifications for. Class must extend
     *                  org.apache.jmeter.gui.action.Command.
     * @param listener
     */
    public void addPostActionListener(Class action, ActionListener listener)
    {
        if (action != null)
        {
            HashSet set = (HashSet) postActionListeners.get(action.getName());
            if (set == null)
            {
                set = new HashSet();
            }
            set.add(listener);
            postActionListeners.put(action.getName(), set);
        }
    }

    /**
     * Allows an ActionListener to be removed from receiving 
     * notifications of a command being executed after the command has executed.
     * 
     * @param action    the Class of the command for which the listener will
     *                  notifications for. Class must extend
     *                  org.apache.jmeter.gui.action.Command.
     * @param listener
     */
    public void removePostActionListener(Class action, ActionListener listener)
    {
        if (action != null)
        {
            HashSet set = (HashSet) postActionListeners.get(action.getName());
            if (set != null)
            {
                set.remove(listener);
                postActionListeners.put(action.getName(), set);
            }
        }
    }

    protected void preActionPerformed(Class action, ActionEvent e)
    {
        if (action != null)
        {
            HashSet listenerSet =
                (HashSet) preActionListeners.get(action.getName());
            if (listenerSet != null && listenerSet.size() > 0)
            {
                Object[] listeners = listenerSet.toArray();
                for (int i = 0; i < listeners.length; i++)
                {
                    ((ActionListener) listeners[i]).actionPerformed(e);
                }
            }
        }
    }

    protected void postActionPerformed(Class action, ActionEvent e)
    {
        if (action != null)
        {
            HashSet listenerSet =
                (HashSet) postActionListeners.get(action.getName());
            if (listenerSet != null && listenerSet.size() > 0)
            {
                Object[] listeners = listenerSet.toArray();
                for (int i = 0; i < listeners.length; i++)
                {
                    ((ActionListener) listeners[i]).actionPerformed(e);
                }
            }
        }
    }

    private void populateCommandMap()
    {
        List listClasses;
        Command command;
        Iterator iterClasses;
        Class commandClass;
        try
        {
            listClasses =
                ClassFinder.findClassesThatExtend(
                    JMeterUtils.getSearchPaths(),
                    new Class[] {
                        Class.forName(
                            "org.apache.jmeter.gui.action.Command")});
            commands = new HashMap(listClasses.size());
            if (listClasses.size() == 0)
            {
                log.warn("!!!!!Uh-oh, didn't find any action handlers!!!!!");
            }
            iterClasses = listClasses.iterator();
            while (iterClasses.hasNext())
            {
                String strClassName = (String) iterClasses.next();
                commandClass = Class.forName(strClassName);
                if (!Modifier.isAbstract(commandClass.getModifiers()))
                {
                    command = (Command) commandClass.newInstance();
                    Iterator iter = command.getActionNames().iterator();
                    while (iter.hasNext())
                    {
                        String commandName = (String) iter.next();
                        Set commandObjects = (Set) commands.get(commandName);
                        if (commandObjects == null)
                        {
                            commandObjects = new HashSet();
                            commands.put(commandName, commandObjects);
                        }
                        commandObjects.add(command);
                    }
                }
            }
        }
        catch (Exception e)
        {
        	if ("java.awt.HeadlessException".equals(e.getClass().getName())) //JDK1.4:
        	{
        		log.warn(e.toString());
        	}
        	else
        	{
                log.error("exception finding action handlers", e);
        	}
        }
    }

    /**
     *  Gets the Instance attribute of the ActionRouter class
     *
     *@return    The Instance value
     */
    public static ActionRouter getInstance()
    {
        if (router == null)
        {
            router = new ActionRouter();
            router.populateCommandMap();
        }
        return router;
    }
}