/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2014 by RapidMiner and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapidminer.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.tools;

import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * @param the argument that is expected when observing other classes
 * 
 * @author Nils Woehler
 *
 */
public abstract class AbstractChangeAwareSaveable<O> extends AbstractObservable<ChangeAwareSaveable> implements ChangeAwareSaveable {

	private static final Logger LOGGER = Logger.getLogger(AbstractChangeAwareSaveable.class.getName());

	private transient boolean isModified = false;

	private DelegatingObserver<O, ChangeAwareSaveable> delegatingObserver = new DelegatingObserver<O, ChangeAwareSaveable>(this, this);

	protected void observeForChanges(Observable<O> observable) {
		if (observable != null) {
			observable.addObserver(delegatingObserver, false);
		}
	}

	protected void stopObservingForChanges(Observable<O> observable) {
		if (observable != null) {
			observable.removeObserver(delegatingObserver);
		}
	}

	@Override
	protected void fireUpdate(ChangeAwareSaveable argument) {
		LOGGER.log(Level.FINE, "Fire update called");
		LOGGER.log(Level.FINE, "Is modified: " + isModified());
		LOGGER.log(Level.FINE, "Is initialized: " + isInitialized());
		if (!isModified() && isInitialized()) {
			setIsModified(true);
			LOGGER.log(Level.FINE, "Notify observers of changed state: CHANGED");
			super.fireUpdate(argument);
		}
	}

	@Override
	public void saved() {
		setIsModified(false);
		LOGGER.log(Level.FINE, "Set changed state to UNCHANGED");
	}

	@Override
	public boolean isModified() {
		return isModified;
	}

	/**
	 * @param isModified the isModified to set
	 */
	public void setIsModified(boolean isModified) {
		LOGGER.log(Level.FINE, "Set is modified to " + isModified);
		this.isModified = isModified;
	}

}