/** Copyright (C) 2017 by Bundesanstalt für Gewässerkunde
 * Software engineering by
 *  Björnsen Beratende Ingenieure GmbH
 *  Dr. Schumacher Ingenieurbüro für Wasser und Umwelt
 *
 * This file is Free Software under the GNU AGPL (>=v3)
 * and comes with ABSOLUTELY NO WARRANTY! Check out the
 * documentation coming with Dive4Elements River for details.
 */
package org.dive4elements.river.jfree;

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.awt.image.BufferedImageOp;
import java.awt.image.LookupOp;
import java.io.IOException;

import javax.imageio.ImageIO;

import org.apache.log4j.Logger;

/**
 * Fill patterns for area styles.
 * REMARK: if this enum is changed, probably the ui in StyleEditorWindow must be changed too
 *
 * @author Gernot Belger
 */
public enum AreaFillPattern {

    patternFill("/images/areapatterns/patternFill.png"), //
    patternPoints("/images/areapatterns/patternPoints.png"), //
    paternCross("/images/areapatterns/paternCross.png"), //
    patternDagonalLeft("/images/areapatterns/patternDagonalLeft.png"), //
    patternDiagonalRight("/images/areapatterns/patternDiagonalRight.png");

    private static Logger log = Logger.getLogger(AreaFillPattern.class);

    private static final BufferedImage MISSING_IMAGE = new BufferedImage(16, 16, BufferedImage.TYPE_INT_RGB);

    private final String imagePath;

    private BufferedImage image = null;

    AreaFillPattern(final String imagePath) {
        this.imagePath = imagePath;
    }

    public BufferedImage getImage(final Color color) {

        if (this.image == null)
            this.image = loadImage();

        if (color == null)
            return this.image;

        /*
         * apply color and transparency, the .png must be encoded as 32bit images (rgba), with only black as non transparent
         * color
         */
        final int numComponents = this.image.getColorModel().getNumComponents();
        if (numComponents != 4) {
            log.warn(String.format("Pattern image must be a 32bit image (rgba): %s", this.imagePath));
            return this.image;
        }

        final BufferedImageOp lookup = new LookupOp(new ColorMapper(Color.black, color), null);
        return lookup.filter(this.image, null);
    }

    private BufferedImage loadImage() {
        try {
            return ImageIO.read(getClass().getResource(this.imagePath));
        }
        catch (final IOException e) {
            log.error(String.format("failed ot load pattern: %s", this.imagePath), e);
            return MISSING_IMAGE;
        }
    }
}