/*
 *    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.util;

import org.geotools.factory.Hints;

import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.Envelope;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.io.WKTReader;

/**
 * Converter factory performing converstions among geometric types.
 * <p>
 * Supported conversions:
 * <ul>
 * 	<li>{@link String} to {@link com.vividsolutions.jts.geom.Geometry}
 *  <li>{@link com.vividsolutions.jts.geom.Geometry} to {@link String}
 * 	<li>{@link com.vividsolutions.jts.geom.Envelope} to {@link com.vividsolutions.jts.geom.Geometry}
 *  <li>{@link com.vividsolutions.jts.geom.Geometry} to {@link com.vividsolutions.jts.geom.Envelope} 
 *  <li>
 * </ul>
 * </p>
 * @author Justin Deoliveira, The Open Planning Project
 * @since 2.4
 *
 *
 * @source $URL$
 */
public class GeometryConverterFactory implements ConverterFactory {

	public Converter createConverter(Class source, Class target, Hints hints) {
	
		if ( Geometry.class.isAssignableFrom( target ) ) {
			
			//String to Geometry
			if ( String.class.equals( source ) ) {
				return new Converter() {
					public Object convert(Object source, Class target) throws Exception {
						return new WKTReader().read( (String) source );
					}
				};
			}
			
			//Envelope to Geometry
			if ( Envelope.class.isAssignableFrom( source ) ) {
				return new Converter() {
					public Object convert(Object source, Class target) throws Exception {
						Envelope e = (Envelope) source;
						GeometryFactory factory = new GeometryFactory();
						return factory.createPolygon(
							factory.createLinearRing( 
								new Coordinate[] {
									new Coordinate( e.getMinX(), e.getMinY() ),
									new Coordinate( e.getMaxX(), e.getMinY() ), 
									new Coordinate( e.getMaxX(), e.getMaxY() ), 
									new Coordinate( e.getMinX(), e.getMaxY() ),
									new Coordinate( e.getMinX(), e.getMinY() )
								}
							), null
						);
					}
				};
			}
		}
		
		if ( Geometry.class.isAssignableFrom( source ) ) {
			//Geometry to envelope
			if ( Envelope.class.equals( target ) ) {
				return new Converter() {
					public Object convert(Object source, Class target) throws Exception {
						Geometry geometry = (Geometry) source;
						return geometry.getEnvelopeInternal();
					}
				};
			}
			
			//Geometry to String
			if ( String.class.equals( target ) ) {
				return new Converter() {
					public Object convert(Object source, Class target) throws Exception {
						Geometry geometry = (Geometry) source;
						return geometry.toText();
					}
				};
			}
		}
		
		return null;
	}
}