// $Header: /home/cvs/jakarta-jmeter/src/core/org/apache/jmeter/control/GenericController.java,v 1.23 2004/02/13 02:21:38 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.control;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import org.apache.jmeter.engine.event.LoopIterationEvent;
import org.apache.jmeter.engine.event.LoopIterationListener;
import org.apache.jmeter.junit.JMeterTestCase;
import org.apache.jmeter.junit.stubs.TestSampler;
import org.apache.jmeter.samplers.Sampler;
import org.apache.jmeter.testelement.AbstractTestElement;
import org.apache.jmeter.testelement.TestElement;
import org.apache.jorphan.logging.LoggingManager;
import org.apache.log.Logger;

/**
 * @author  Michael Stover
 * @author  Thad Smith
 * @version $Revision: 1.23 $
 */
public class GenericController
    extends AbstractTestElement
    implements Controller, Serializable
{
    protected static final Logger log = LoggingManager.getLoggerForClass();

    protected LinkedList iterationListeners = new LinkedList();
    protected List subControllersAndSamplers = new ArrayList();

    protected int current;
    private int iterCount;
    private boolean done, first;

    /**
     * Creates a Generic Controller
     */
    public GenericController(){}

    public void initialize()
    {
        resetCurrent();
        resetIterCount();
        done = false;
        first = true;
        TestElement elem;
        for (int i = 0; i < subControllersAndSamplers.size(); i++)
        {
            elem = (TestElement) subControllersAndSamplers.get(i);
            if (elem instanceof Controller)
            {
                ((Controller) elem).initialize();
            }
        }
    }

    protected void reInitialize()
    {
        resetCurrent();
        incrementIterCount();
        setFirst(true);
    }

    /**
     * @see org.apache.jmeter.control.Controller#next()
     */
    public Sampler next()
    {
        fireIterEvents();
        log.debug("Calling next on: " + this.getClass().getName());
        if (isDone()) return null;
        Sampler returnValue = null;
        TestElement currentElement = null;
        try
        {
            currentElement = getCurrentElement();
            setCurrentElement(currentElement);
            if (currentElement == null)
            {
                //incrementCurrent();  
                returnValue = nextIsNull();
            }
            else
            {
                if (currentElement instanceof Sampler)
                {
                    returnValue = nextIsASampler((Sampler) currentElement);
                }
                else
                {
                    returnValue =
                        nextIsAController((Controller) currentElement);
                }
            }
        }
        catch (NextIsNullException e)
        {
            returnValue = null;
        }
        return returnValue;
    }

    /**
     * @see org.apache.jmeter.control.Controller#isDone()
     */
    public boolean isDone()
    {
        return done;
    }

    protected void setDone(boolean done)
    {
        this.done = done;
    }

    protected boolean isFirst()
    {
        return first;
    }

    public void setFirst(boolean b)
    {
        first = b;
    }

    protected Sampler nextIsAController(Controller controller)
        throws NextIsNullException
    {
        Sampler returnValue;
        Sampler sampler = controller.next();
        if (sampler == null)
        {
            currentReturnedNull(controller);
            returnValue = next();
        }
        else
        {
            returnValue = sampler;
        }
        return returnValue;
    }

    protected Sampler nextIsASampler(Sampler element) throws NextIsNullException
    {
        incrementCurrent();
        return element;
    }

    protected Sampler nextIsNull() throws NextIsNullException
    {
        reInitialize();
        return null;
    }

    protected void currentReturnedNull(Controller c)
    {
        if (c.isDone())
        {
            removeCurrentElement();
        }
        else
        {
            incrementCurrent();
        }
    }

    /**
     * Gets the SubControllers attribute of the 
     * GenericController object
     *
     * @return  the SubControllers value
     */
    protected List getSubControllers()
    {
        return subControllersAndSamplers;
    }

    private void addElement(TestElement child)
    {
        subControllersAndSamplers.add(child);
    }

    protected void setCurrentElement(TestElement currentElement)
        throws NextIsNullException
    {
    }

    protected TestElement getCurrentElement() throws NextIsNullException
    {
        if (current < subControllersAndSamplers.size())
        {
            return (TestElement) subControllersAndSamplers.get(current);
        }
        else
        {
            if (subControllersAndSamplers.size() == 0)
            {
                setDone(true);
                throw new NextIsNullException();
            }
            return null;
        }
    }

    protected void removeCurrentElement()
    {
        subControllersAndSamplers.remove(current);
    }

    protected void incrementCurrent()
    {
        current++;
    }

    protected void resetCurrent()
    {
        current = 0;
    }

    public void addTestElement(TestElement child)
    {
        if (child instanceof Controller || child instanceof Sampler)
        {
            addElement(child);
        }
    }

    public void addIterationListener(LoopIterationListener lis)
    {
        /* A little hack - add each listener to the start of the list - this
         * ensures that the thread running the show is the first listener and
         * can modify certain values before other listeners are called.
         */
        iterationListeners.addFirst(lis);
    }

    protected void fireIterEvents()
    {
        if (isFirst())
        {
            fireIterationStart();
            first = false;
        }
    }

    protected void fireIterationStart()
    {
        Iterator iter = iterationListeners.iterator();
        LoopIterationEvent event = new LoopIterationEvent(this, getIterCount());
        while (iter.hasNext())
        {
            LoopIterationListener item = (LoopIterationListener) iter.next();
            item.iterationStart(event);
        }
    }

    protected int getIterCount()
    {
        return iterCount;
    }

    protected void incrementIterCount()
    {
        iterCount++;
    }

    protected void resetIterCount()
    {
        iterCount = 0;
    }

    public static class Test extends JMeterTestCase
    {
        public Test(String name)
        {
            super(name);
        }

        public void testProcessing() throws Exception
        {
            testLog.debug("Testing Generic Controller");
            GenericController controller = new GenericController();
            GenericController sub_1 = new GenericController();
            sub_1.addTestElement(new TestSampler("one"));
            sub_1.addTestElement(new TestSampler("two"));
            controller.addTestElement(sub_1);
            controller.addTestElement(new TestSampler("three"));
            GenericController sub_2 = new GenericController();
            GenericController sub_3 = new GenericController();
            sub_2.addTestElement(new TestSampler("four"));
            sub_3.addTestElement(new TestSampler("five"));
            sub_3.addTestElement(new TestSampler("six"));
            sub_2.addTestElement(sub_3);
            sub_2.addTestElement(new TestSampler("seven"));
            controller.addTestElement(sub_2);
            String[] order =
                new String[] {
                    "one",
                    "two",
                    "three",
                    "four",
                    "five",
                    "six",
                    "seven" };
            int counter = 7;
            controller.initialize();
            for (int i = 0; i < 2; i++)
            {
                assertEquals(7, counter);
                counter = 0;
                TestElement sampler = null;
                while ((sampler = controller.next()) != null)
                {
                    assertEquals(
                        order[counter++],
                        sampler.getPropertyAsString(TestElement.NAME));
                }
            }
        }
    }
}