/*
 *    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.
 */
package org.geotools.coverage.grid;

import java.awt.Rectangle;
import java.awt.geom.AffineTransform;
import java.awt.geom.Point2D;
import java.awt.image.Raster;
import java.io.IOException;
import java.net.InetAddress;

import javax.media.jai.BorderExtender;
import javax.media.jai.Interpolation;
import javax.media.jai.PlanarImage;

import org.opengis.coverage.grid.GridEnvelope;
import org.opengis.geometry.Envelope;

import org.geotools.referencing.operation.matrix.XAffineTransform;
import org.junit.*;
import static org.junit.Assert.*;


/**
 * Tests the {@link Interpolator2D} implementation.
 *
 *
 * @source $URL$
 * @version $Id$
 * @author Martin Desruisseaux (IRD)
 */
public final class InterpolatorTest extends GridCoverageTestBase {
    /**
     * The interpolators to use.
     */
    private Interpolation[] interpolations;
    
    /** Used to avoid errors if building on a system where hostname is not defined */
    private boolean hostnameDefined;

    /**
     * Setup the {@linkplain #interpolations} values.
     */
    @Before
    public void setup() {
        final int[] types = {
            Interpolation.INTERP_BICUBIC,
            Interpolation.INTERP_BILINEAR,
            Interpolation.INTERP_NEAREST
        };
        interpolations = new Interpolation[types.length];
        for (int i=0; i<interpolations.length; i++) {
            interpolations[i] = Interpolation.getInstance(types[i]);
        }
        
        
        try {
            InetAddress.getLocalHost();
            hostnameDefined = true;
            
        } catch (Exception ex) {
            hostnameDefined = false;
        }
    }

    /**
     * Tests bilinear intersection at pixel edges. It should be equals
     * to the average of the four pixels around.
     */
    @Test
    public void testInterpolationAtEdges() {
        // Following constant is pixel size (in degrees).
        // This constant must be identical to the one defined in 'getRandomCoverage()'
        GridCoverage2D coverage = getRandomCoverage();
        final double PIXEL_SIZE = XAffineTransform.getScale((AffineTransform) ((GridGeometry2D)coverage.getGridGeometry()).getGridToCRS());
        coverage = coverage.view(ViewType.GEOPHYSICS);
        final Interpolation interpolation =  Interpolation.getInstance(Interpolation.INTERP_BILINEAR);
        coverage = Interpolator2D.create(coverage, new Interpolation[] {interpolation});
        final int  band = 0; // Band to test.
        double[] buffer = null;
        final BorderExtender be =  BorderExtender.createInstance(BorderExtender.BORDER_COPY);
        Rectangle  rectangle = PlanarImage.wrapRenderedImage(coverage.getRenderedImage()).getBounds();
        rectangle			 = new Rectangle(rectangle.x,rectangle.y,rectangle.width+interpolation.getWidth(), rectangle.height+interpolation.getHeight());
        final Raster          data = PlanarImage.wrapRenderedImage(coverage.getRenderedImage()).getExtendedData(rectangle,be);
        final Envelope    envelope = coverage.getEnvelope();
        final GridEnvelope   range = coverage.getGridGeometry().getGridRange();
        final double          left = envelope.getMinimum(0);
        final double         upper = envelope.getMaximum(1);
        final Point2D.Double point = new Point2D.Double(); // Will maps to pixel upper-left corner
        for (int j=range.getSpan(1); j>=0;--j) {
            for (int i=range.getSpan(0); i>=0;--i) {
                point.x  = left  + PIXEL_SIZE*i;
                point.y  = upper - PIXEL_SIZE*j;
                buffer   = coverage.evaluate(point, buffer);
                double t = buffer[band];

                // Computes the expected value:
                double s00 = data.getSampleDouble(i+0, j+0, band);
                double s01 = data.getSampleDouble(i+0, j+1, band);
                double s10 = data.getSampleDouble(i+1, j+0, band);
                double s11 = data.getSampleDouble(i+1, j+1, band);
                double s = interpolation.interpolate(s00, s01, s10, s11, 0, 0);
                assertEquals(s, t, EPS);
            }
        }
    }

    /**
     * Tests the serialization of a grid coverage.
     *
     * @throws IOException if an I/O operation was needed and failed.
     * @throws ClassNotFoundException Should never happen.
     */
    @Test
    public void testSerialization() throws IOException, ClassNotFoundException {
        if (hostnameDefined) {
            GridCoverage2D coverage = EXAMPLES.get(0);
            coverage = Interpolator2D.create(coverage, interpolations);
            GridCoverage2D serial = serialize(coverage);
            assertNotSame(coverage, serial);
            assertEquals(Interpolator2D.class, serial.getClass());
            // Compares the geophysics view for working around the
            // conversions of NaN values which may be the expected ones.
            coverage = coverage.view(ViewType.GEOPHYSICS);
            serial = serial.view(ViewType.GEOPHYSICS);
            assertRasterEquals(coverage, serial);
        }
    }
}