/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2004-2008, 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.
 */
package org.geotools.brewer.color;


//import edu.psu.geovista.colorbrewer.OriginalColor;
import java.awt.Color;
import java.util.List;

import org.geotools.factory.CommonFactoryFinder;
import org.geotools.filter.FunctionExpression;
import org.geotools.filter.FunctionExpressionImpl;
import org.geotools.filter.function.ClassificationFunction;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.filter.FilterFactory;
import org.opengis.filter.expression.Expression;
import org.opengis.filter.expression.Literal;


/**
 *
 * @author James Macgill
 *
 * @source $URL$
 */
public class PaletteFunction extends FunctionExpressionImpl implements FunctionExpression {
    ClassificationFunction classifier;
    String paletteName;
    FilterFactory ff;

    /** Creates a new instance of PaletteFunction */
    public PaletteFunction() {
        this(CommonFactoryFinder.getFilterFactory(null));
    }

    public PaletteFunction(FilterFactory factory) {
        super("Palette");
        ff = factory;
    }

    public void setFilterFactory(FilterFactory factory) {
        ff = factory;
    }

    public int getArgCount() {
        return 2;
    }

    public void setParameters(List args) {
        super.setParameters(args);
        classifier = (ClassificationFunction) getExpression(0);
        paletteName = ((Literal) getExpression(1)).evaluate(null, String.class);
    }

    public Expression getEvaluationExpression() {
        return classifier.getExpression();
    }

    public void setEvaluationExpression(Expression e) {
        classifier.setExpression((org.geotools.filter.Expression) e);
    }

    public ClassificationFunction getClassifier() {
        return classifier;
    }

    public void setClassifier(ClassificationFunction cf) {
        classifier = cf;
    }

    public int getNumberOfClasses() {
        return classifier.getClasses();
    }

    public void setNumberOfClasses(int i) {
        classifier.setClasses(i);
    }

    public String getPaletteName() {
        return paletteName;
    }

    public void setPaletteName(String s) {
        paletteName = s;
    }

    private String intToHex(int i) {
        String prelim = Integer.toHexString(i);

        while (prelim.length() < 2) {
            prelim = "0" + prelim;
        }

        if (prelim.length() > 2) {
            prelim = prelim.substring(0, 1);
        }

        return prelim;
    }

    public Object evaluate(SimpleFeature feature) {
        int classNum = classifier.getClasses();
        ColorBrewer brewer = new ColorBrewer();
        int klass = ((Integer) classifier.evaluate(feature)).intValue();

        BrewerPalette pal = brewer.getPalette(paletteName);
        Color[] colors = pal.getColors(classNum);
        String color = "#" + intToHex(colors[klass].getRed()) + intToHex(colors[klass].getGreen())
            + intToHex(colors[klass].getBlue());

        return color;
    }

    public String toString() {
        return "Color Brewer palette";
    }
}