/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.jmeter.samplers.Sampler;
import org.apache.jmeter.testelement.TestElement;
import org.apache.jmeter.testelement.property.IntegerProperty;

public class InterleaveControl extends GenericController implements Serializable {
	private static final String STYLE = "InterleaveControl.style";// $NON-NLS-1$

	public static final int IGNORE_SUB_CONTROLLERS = 0;

	public static final int USE_SUB_CONTROLLERS = 1;

	private boolean skipNext;

	private transient TestElement searchStart = null;

	private boolean currentReturnedAtLeastOne;

	private boolean stillSame = true;

	/***************************************************************************
	 * Constructor for the InterleaveControl object
	 **************************************************************************/
	public InterleaveControl() {
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.apache.jmeter.control.GenericController#reInitialize()
	 */
	public void reInitialize() {
		setFirst(true);
		currentReturnedAtLeastOne = false;
		searchStart = null;
		stillSame = true;
		skipNext = false;
		incrementIterCount();
		recoverRunningVersion();
	}

	public void setStyle(int style) {
		setProperty(new IntegerProperty(STYLE, style));
	}

	public int getStyle() {
		return getPropertyAsInt(STYLE);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.apache.jmeter.control.Controller#next()
	 */
	public Sampler next() {
		if (isSkipNext()) {
			reInitialize();
			return null;
		}
		return super.next();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see GenericController#nextIsAController(Controller)
	 */
	protected Sampler nextIsAController(Controller controller) throws NextIsNullException {
		Sampler sampler = controller.next();
		if (sampler == null) {
			currentReturnedNull(controller);
			return next();
		}
		currentReturnedAtLeastOne = true;
		if (getStyle() == IGNORE_SUB_CONTROLLERS) {
			incrementCurrent();
			skipNext = true;
		} else {
			searchStart = null;
		}
		return sampler;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.apache.jmeter.control.GenericController#nextIsASampler(Sampler)
	 */
	protected Sampler nextIsASampler(Sampler element) throws NextIsNullException {
		skipNext = true;
		incrementCurrent();
		return element;
	}

	/**
	 * If the current is null, reset and continue searching. The searchStart
	 * attribute will break us off when we start a repeat.
	 * 
	 * @see org.apache.jmeter.control.GenericController#nextIsNull()
	 */
	protected Sampler nextIsNull() {
		resetCurrent();
		return next();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see GenericController#setCurrentElement(TestElement)
	 */
	protected void setCurrentElement(TestElement currentElement) throws NextIsNullException {
		// Set the position when next is first called, and don't overwrite
		// until reInitialize is called.
		if (searchStart == null) {
			searchStart = currentElement;
		} else if (searchStart == currentElement && !stillSame) {
			// We've gone through the whole list and are now back at the start
			// point of our search.
			reInitialize();
			throw new NextIsNullException();
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see GenericController#currentReturnedNull(Controller)
	 */
	protected void currentReturnedNull(Controller c) {
		if (c.isDone()) {
			removeCurrentElement();
		} else if (getStyle() == USE_SUB_CONTROLLERS) {
			incrementCurrent();
		}
	}

	/**
	 * @return skipNext
	 */
	protected boolean isSkipNext() {
		return skipNext;
	}

	/**
	 * @param skipNext
	 */
	protected void setSkipNext(boolean skipNext) {
		this.skipNext = skipNext;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.apache.jmeter.control.GenericController#incrementCurrent()
	 */
	protected void incrementCurrent() {
		if (currentReturnedAtLeastOne) {
			skipNext = true;
		}
		stillSame = false;
		super.incrementCurrent();
	}
}
