/*
 * (c) Copyright 2008-2010 by Volker Bergmann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, is permitted under the terms of the
 * GNU General Public License.
 *
 * For redistributing this software or a derivative work under a license other
 * than the GPL-compatible Free Software License as defined by the Free
 * Software Foundation or approved by OSI, you must first obtain a commercial
 * license to this software product from Volker Bergmann.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * WITHOUT A WARRANTY OF ANY KIND. ALL EXPRESS OR IMPLIED CONDITIONS,
 * REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE
 * HEREBY EXCLUDED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

package org.databene.benerator.distribution;

import org.databene.commons.Converter;
import org.databene.commons.NullSafeComparator;
import org.databene.commons.accessor.FeatureAccessor;
import org.databene.commons.converter.AnyConverter;

/**
 * Implements the IndividualWeight function for arbitrary feature names, 
 * supporting e.g. properties, attributes, or Map keys.<br/><br/>
 * Created at 27.04.2008 17:23:45
 * @since 0.5.2
 * @author Volker Bergmann
 */
public class FeatureWeight extends IndividualWeight<Object> {

	private String feature;
	
    private FeatureAccessor<Object, Double> accessor;
	private Converter<Object, Double> converter;

	// constructors ----------------------------------------------------------------------------------------------------
	
	public FeatureWeight() {
		this("weight");
	}

	public FeatureWeight(String feature) {
		this.feature = feature;
		this.accessor = new FeatureAccessor<Object, Double>(feature);
		this.converter = new AnyConverter<Double>(Double.class);
	}
	
	// interface -------------------------------------------------------------------------------------------------------

	public String getWeightFeature() {
		return accessor.getFeatureName();
	}

	public void setWeightFeature(String weightFeature) {
		this.accessor.setFeatureName(weightFeature);
	}

	@Override
    public double weight(Object object) {
		return converter.convert(accessor.getValue(object));
	}
	
    // java.lang.Object overrides --------------------------------------------------------------------------------------

	@Override
	public int hashCode() {
		return accessor.getFeatureName().hashCode();
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		final FeatureWeight that = (FeatureWeight) obj;
		return NullSafeComparator.equals(this.getWeightFeature(), that.getWeightFeature());
	}
	
	@Override
	public String toString() {
		return getClass().getSimpleName() + '[' + feature + ']';
	}

}