/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2016 Open Source Geospatial Foundation (OSGeo)
 *    (C) 2014-2016 Boundless Spatial
 *
 *    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.ysld;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import org.opengis.style.ChannelSelection;
import org.opengis.style.SelectedChannelType;

/**
 * Enumeration for valid raster band values.
 */
public enum Band {
    GRAY("gray") {

        @Override
        public org.opengis.style.SelectedChannelType getFrom(
                org.opengis.style.ChannelSelection sel) {
            return sel.getGrayChannel();
        }

        @Override
        public void setTo(org.geotools.styling.ChannelSelection sel,
                org.geotools.styling.SelectedChannelType chan) {
            sel.setGrayChannel(chan);
        }
    },
    RED("red") {
        @Override
        public SelectedChannelType getFrom(ChannelSelection sel) {
            return sel.getRGBChannels()[0];
        }

        @Override
        public void setTo(org.geotools.styling.ChannelSelection sel,
                org.geotools.styling.SelectedChannelType chan) {
            org.geotools.styling.SelectedChannelType channels[] = sel.getRGBChannels();
            channels[0] = chan;
            sel.setRGBChannels(channels);
        }
    },
    GREEN("green") {
        @Override
        public SelectedChannelType getFrom(ChannelSelection sel) {
            return sel.getRGBChannels()[1];
        }

        @Override
        public void setTo(org.geotools.styling.ChannelSelection sel,
                org.geotools.styling.SelectedChannelType chan) {
            org.geotools.styling.SelectedChannelType channels[] = sel.getRGBChannels();
            channels[1] = chan;
            sel.setRGBChannels(channels);
        }
    },
    BLUE("blue") {
        @Override
        public SelectedChannelType getFrom(ChannelSelection sel) {
            return sel.getRGBChannels()[2];
        }

        @Override
        public void setTo(org.geotools.styling.ChannelSelection sel,
                org.geotools.styling.SelectedChannelType chan) {
            org.geotools.styling.SelectedChannelType channels[] = sel.getRGBChannels();
            channels[2] = chan;
            sel.setRGBChannels(channels);
        }
    };

    /**
     * A list of the bands representing Red, Green, Blue (in order).
     */
    public static final List<Band> RGB = Collections
            .unmodifiableList(Arrays.asList(RED, GREEN, BLUE));

    /**
     * Get the {@link SelectedChannelType} in sel that is represented by this band.
     * @param sel
     */
    abstract public org.opengis.style.SelectedChannelType getFrom(
            org.opengis.style.ChannelSelection sel);

    /**
     * Set the {@link SelectedChannelType} in sel that is represented by this band to chan.
     * @param sel
     * @param chan
     */
    abstract public void setTo(org.geotools.styling.ChannelSelection sel,
            org.geotools.styling.SelectedChannelType chan);

    public final String key;

    private Band(String key) {
        this.key = key;
    }
}