/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2011, Open Source Geospatial Foundation (OSGeo)
 *    (C) 2008-2011 TOPP - www.openplans.org.
 *
 *    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.process.raster.gs;

import java.io.IOException;

import org.geotools.process.factory.DescribeParameter;
import org.geotools.process.factory.DescribeProcess;
import org.geotools.process.factory.DescribeResult;
import org.geotools.process.gs.GSProcess;
import org.geotools.coverage.grid.GridCoverage2D;
import org.geotools.coverage.processing.CoverageProcessor;
import org.geotools.geometry.GeneralEnvelope;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.opengis.coverage.processing.Operation;
import org.opengis.parameter.ParameterValueGroup;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.opengis.util.ProgressListener;

import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryCollection;

/**
 * Crops the coverage along the specified 
 * 
 * @author Andrea Aime - GeoSolutions
 * @author ETj <etj at geo-solutions.it>
 *
 * @source $URL$
 */
@DescribeProcess(title = "cropCoverage", description = "Collects all the default geometries in the feature collection and returns them as a single geometry collection")
public class CropCoverage implements GSProcess {

    private static final CoverageProcessor PROCESSOR = CoverageProcessor.getInstance();
    private static final Operation CROP = PROCESSOR.getOperation("CoverageCrop");

    @DescribeResult(name = "result", description = "The cropped raster")
    public GridCoverage2D execute(
            @DescribeParameter(name = "coverage", description = "The raster to be cropped") GridCoverage2D coverage,
            @DescribeParameter(name = "cropShape", description = "The geometry used to crop the raster (either single or a collection)") Geometry cropShape,
            ProgressListener progressListener) throws IOException {
        // get the bounds
        CoordinateReferenceSystem crs;
        if (cropShape.getUserData() instanceof CoordinateReferenceSystem) {
            crs = (CoordinateReferenceSystem) cropShape.getUserData();
        } else {
            // assume the geometry is in the same crs
            crs = coverage.getCoordinateReferenceSystem();
        }
        GeneralEnvelope bounds = new GeneralEnvelope(new ReferencedEnvelope(cropShape.getEnvelopeInternal(), crs));

        // force it to a collection if necessary
        GeometryCollection roi;
        if (!(cropShape instanceof GeometryCollection)) {
            roi = cropShape.getFactory().createGeometryCollection(new Geometry[] { cropShape });
        } else {
            roi = (GeometryCollection) cropShape;
        }

        // perform the crops
        final ParameterValueGroup param = CROP.getParameters();
        param.parameter("Source").setValue(coverage);
        param.parameter("Envelope").setValue(bounds);
        param.parameter("ROI").setValue(roi);

        return (GridCoverage2D) PROCESSOR.doOperation(param);
    }

}