/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 * 
 *    (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
 *    
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation;
 *    version 2.1 of the License.
 *
 *    This library 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
 *    Lesser General Public License for more details.
 *
 * Created on 13 November 2002, 13:59
 */
package org.geotools.styling;

import org.geotools.factory.CommonFactoryFinder;
import org.geotools.factory.GeoTools;
import org.geotools.util.Utilities;
import org.opengis.filter.FilterFactory;
import org.opengis.filter.expression.Expression;
import org.opengis.style.StyleVisitor;

/**
 * Default implementation of ShadedRelief.
 *
 * @author iant
 *
 * @source $URL$
 */
public class ShadedReliefImpl implements ShadedRelief {
    private FilterFactory filterFactory;
    private Expression reliefFactor;
    private boolean brightness = false;

    public ShadedReliefImpl(){
        this( CommonFactoryFinder.getFilterFactory(GeoTools.getDefaultHints()));
    }

    public ShadedReliefImpl(FilterFactory factory) {
        filterFactory = factory;
        reliefFactor = filterFactory.literal(55);
    }

    /**
     * The ReliefFactor gives the amount of exaggeration to use for the height
     * of the ?hills.?  A value of around 55 (times) gives reasonable results
     * for Earth-based DEMs. The default value is system-dependent.
     *
     * @return an expression which evaluates to a double.
     */
    public Expression getReliefFactor() {
        return reliefFactor;
    }

    /**
     * indicates if brightnessOnly is true or false. Default is false.
     *
     * @return boolean brightnessOn.
     */
    public boolean isBrightnessOnly() {
        return brightness;
    }

    /**
     * turns brightnessOnly on or off depending on value of flag.
     *
     * @param flag boolean
     */
    public void setBrightnessOnly(boolean flag) {
        brightness = flag;
    }

    /**
     * The ReliefFactor gives the amount of exaggeration to use for the height
     * of the ?hills.?  A value of around 55 (times) gives reasonable results
     * for Earth-based DEMs. The default value is system-dependent.
     *
     * @param reliefFactor an expression which evaluates to a double.
     */
    public void setReliefFactor(Expression reliefFactor) {
        this.reliefFactor = reliefFactor;
    }

    public Object accept(StyleVisitor visitor,Object data) {
	return visitor.visit(this,data);
    }
    
    public void accept(org.geotools.styling.StyleVisitor visitor) {
        visitor.visit( this );
    }
    
    @Override
    public int hashCode() {
        final int PRIME = 1000003;
        int result = 0;

        if (reliefFactor != null){
            result = (PRIME * result) + reliefFactor.hashCode();
        }

        result = (PRIME * result) + (brightness ? 1 : 0);
        
        return result;
    }
    
    @Override
    public boolean equals(Object obj) {
    	if (this == obj) {
            return true;
        }

        if (obj instanceof ShadedReliefImpl) {
        	ShadedReliefImpl other = (ShadedReliefImpl) obj;

            return Utilities.equals(reliefFactor, other.reliefFactor)
            && Utilities.equals(brightness, other.brightness);
        }

        return false;
    }

    static ShadedReliefImpl cast(org.opengis.style.ShadedRelief shadedRelief) {
        if( shadedRelief == null ){
            return null;
        }
        else if ( shadedRelief instanceof ShadedReliefImpl){
            return (ShadedReliefImpl) shadedRelief;
        }
        else {
            ShadedReliefImpl copy = new ShadedReliefImpl();
            copy.setBrightnessOnly( shadedRelief.isBrightnessOnly() );
            copy.setReliefFactor( shadedRelief.getReliefFactor() );
            
            return copy;
        }
    }
}