/*
 *    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.gml4wcs.bindings;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.Collections;
import java.util.List;

import javax.xml.namespace.QName;

import org.geotools.geometry.DirectPosition2D;
import org.geotools.gml2.bindings.GML2EncodingUtils;
import org.geotools.gml3.GML;
import org.geotools.xlink.XLINK;
import org.geotools.xml.ComplexBinding;
import org.geotools.xml.Encoder;
import org.opengis.geometry.DirectPosition;
import org.opengis.referencing.crs.CoordinateReferenceSystem;

import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.CoordinateSequence;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryCollection;
import com.vividsolutions.jts.geom.LineString;


/**
 * Utility class for gml3 encoding.
 *
 * @author Justin Deoliveira, The Open Planning Project, jdeolive@openplans.org
 *
 *
 * @source $URL: http://svn.osgeo.org/geotools/trunk/modules/extension/xsd/xsd-wcs/src/main/java/org/geotools/gml4wcs/bindings/GML3EncodingUtils.java $
 */
public class GML3EncodingUtils {
    static DirectPosition[] positions(LineString line) {
        CoordinateSequence coordinates = line.getCoordinateSequence();
        DirectPosition[] dps = new DirectPosition[coordinates.size()];

        double x;
        double y;

        for (int i = 0; i < dps.length; i++) {
            x = coordinates.getOrdinate(i, 0);
            y = coordinates.getOrdinate(i, 1);
            dps[i] = new DirectPosition2D(x, y);
        }

        return dps;
    }

    static URI toURI(CoordinateReferenceSystem crs) {
        if (crs == null) {
            return null;
        }

        try {
            String crsCode = GML2EncodingUtils.crs(crs);

            if (crsCode != null) {
                return new URI(crsCode);
            } else {
                return null;
            }
        } catch (URISyntaxException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * @deprecated use {@link #toURI(CoordinateReferenceSystem)}.
     */
    static URI crs(CoordinateReferenceSystem crs) {
        return toURI(crs);
    }

    static CoordinateReferenceSystem getCRS(Geometry g) {
        return GML2EncodingUtils.getCRS(g);
    }

    static String getID(Geometry g) {
        return GML2EncodingUtils.getID(g);
    }
    
    static String getName(Geometry g) {
        return GML2EncodingUtils.getName(g);
    }
    
    static String getDescription(Geometry g) {
        return GML2EncodingUtils.getDescription(g);
    }
    
    /**
     * Helper method used to implement {@link ComplexBinding#getProperty(Object, QName)}
     * for bindings of geometry reference types: 
     * <ul>
     *   <li>GeometryPropertyType
     *   <li>PointPropertyType
     *   <li>LineStringPropertyType
     *   <li>PolygonPropertyType
     * </ul>
     */
    static Object getProperty( Geometry geometry, QName name ) {

        if (GML._Geometry.equals(name) || GML.Point.equals( name ) || 
            GML.LineString.equals( name ) || GML.Polygon.equals( name ) ) {
            //if the geometry is null, return null
            if ( isEmpty( geometry ) ) {
                return null;
            }
            
            return geometry;
        }
        
        if (XLINK.HREF.equals(name)) {
            //only process if geometry is empty
            if ( isEmpty(geometry) ) {
                String id = GML3EncodingUtils.getID( geometry );
                if ( id != null ) {
                    return "#" + id;
                }
            }
        }

        return null;
    }
    
    /**
     * Helper method used to implement {@link ComplexBinding#getProperties(Object)}
     * for bindings of geometry reference types: 
     * <ul>
     *   <li>GeometryPropertyType
     *   <li>PointPropertyType
     *   <li>LineStringPropertyType
     *   <li>PolygonPropertyType
     * </ul>
     */
    static List getProperties(Geometry geometry) {

        String id = GML3EncodingUtils.getID( geometry );
        
        if ( !isEmpty(geometry) && id != null ) {
            // return a comment which is hte xlink href
            return Collections.singletonList(new Object[] { Encoder.COMMENT, "#" +id });            
        }
        
        return null;
    }
    
    static boolean isEmpty( Geometry geometry ) {
        if ( geometry.isEmpty() ) {
            //check for case of multi geometry, if it has > 0 goemetries 
            // we consider this to be not empty
            if ( geometry instanceof GeometryCollection ) {
                if ( ((GeometryCollection) geometry).getNumGeometries() != 0 ) {
                    return false;
                }
            }
            return true;
        }
        
        return false;
    }
}