/*
 *    Geotoolkit - An Open Source Java GIS Toolkit
 *    http://www.geotoolkit.org
 *
 *    (C) 2014, 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.filter.function.geometry;

import com.vividsolutions.jts.geom.Geometry;
import org.geotoolkit.filter.function.AbstractFunction;
import org.opengis.filter.expression.Expression;

/**
 * JTS geometry buffer.
 * 
 * @author Johann Sorel (Geomatys)
 */
public class BufferFunction extends AbstractFunction {
    
    public BufferFunction(final Expression expr1, final Expression expr2) {
        super(GeometryFunctionFactory.BUFFER, new Expression[] {expr1, expr2}, null);
    }

    @Override
    public Object evaluate(final Object feature) {
        final Geometry geom;
        double width;

        try {
            geom = parameters.get(0).evaluate(feature,Geometry.class);
            width = parameters.get(1).evaluate(feature,Number.class).doubleValue();
        } catch (Exception e){
            throw new IllegalArgumentException("Invalid function parameter."+
                    parameters.get(0)+" "+parameters.get(1));
        }

        if(width==0) return geom;
        
        final Geometry geomBuf = geom.buffer(width);
        geomBuf.setSRID(geom.getSRID());
        geomBuf.setUserData(geom.getUserData());
        return geomBuf;
    }
}