/*
 *    Geotoolkit - An Open Source Java GIS Toolkit
 *    http://www.geotoolkit.org
 *
 *    (C) 2009 Geomatys
 *
 *    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.geotoolkit.style.interval;

import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.LinearGradientPaint;
import java.awt.MultipleGradientPaint;
import java.awt.Rectangle;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.AbstractMap.SimpleImmutableEntry;
import java.util.ArrayList;
import java.util.List;
import java.util.Map.Entry;

/**
 *
 * @author Johann Sorel (Geomatys)
 * @module
 */
public class DefaultRandomPalette implements RandomPalette{

    private static final float[] fractions = new float[32];
    private static final Color[] colors = new Color[32];
    static {
        for(int i=0;i<colors.length;i++){
            fractions[i] = (float)i / (colors.length-1);
            colors[i] = new Color((float)Math.random(), (float)Math.random(), (float)Math.random(), 1f);
        }
    }

    @Override
    public Color next() {
        return new Color((float)Math.random(), (float)Math.random(), (float)Math.random(), 1f);
    }

    @Override
    public void render(final Graphics2D g, final Rectangle rectangle, boolean interpolate) {

        if(interpolate){

            final MultipleGradientPaint.CycleMethod cycleMethod = MultipleGradientPaint.CycleMethod.NO_CYCLE;
            final MultipleGradientPaint.ColorSpaceType colorSpace = MultipleGradientPaint.ColorSpaceType.SRGB;

            final LinearGradientPaint paint = new LinearGradientPaint(
                new Point2D.Double(rectangle.getMinX(),rectangle.getMinY()),
                new Point2D.Double(rectangle.getMaxX(),rectangle.getMinY()),
                fractions,
                colors,
                cycleMethod
            );
            g.setPaint(paint);
            g.fill(rectangle);
        }else{
            double step = rectangle.getWidth()/colors.length;
            double start = rectangle.getX();
            for(int i=0;i<colors.length;i++){
                g.setColor(colors[i]);
                g.fill(new Rectangle2D.Double(start, rectangle.getY(), step, rectangle.getHeight()));
                start += step;
            }
        }

        g.setColor(Color.WHITE);
        final Font font = new Font("Dialog", Font.BOLD, 13);
        final FontMetrics fm = g.getFontMetrics(font);
        final String text = "Random";
        final Rectangle2D rect = fm.getStringBounds(text, g);
        g.drawString(text,
                (float)( (rectangle.getWidth()-rect.getWidth())/2),
                (float)(rectangle.getHeight() - (rectangle.getHeight()-rect.getHeight())/2) );

    }

    @Override
    public List<Entry<Double, Color>> getSteps() {
        final List<Entry<Double, Color>> steps = new ArrayList<Entry<Double, Color>>();     
        steps.add(new SimpleImmutableEntry<Double, Color>(0d, next()));
        steps.add(new SimpleImmutableEntry<Double, Color>(0.5d, next()));
        steps.add(new SimpleImmutableEntry<Double, Color>(1d, next()));
        return steps;
    }

}