/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2002-2011, 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.data.efeature.util;

import java.math.BigInteger;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.eclipse.emf.ecore.EDataType;
import org.eclipse.emf.ecore.EFactory;
import org.eclipse.emf.ecore.xmi.impl.XMLHelperImpl;
import org.geotools.data.efeature.DataBuilder;
import org.geotools.data.efeature.DataTypes;
import org.geotools.util.logging.Logging;

import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.io.ParseException;

/**
 * @author kengu
 *
 */
public class EFeatureXMLHelper extends XMLHelperImpl {
    
    /**
     * Cached {@link Logger} for this class
     */
    protected static final Logger LOGGER = Logging.getLogger(EFeatureXMLHelper.class);

    @Override
    public String convertToString(EFactory factory, EDataType dataType, Object value) {
        //
        // Only serialize Geometry instances
        //
        if(value instanceof Geometry) {
            //
            // Convert geometry to byte array
            //
            byte[] b = DataBuilder.toWKB((Geometry)value);
            //
            // Convert to compressed string
            //
            return toString(b);
            //return DataBuilder.toWKT((Geometry)value);
        }
        //
        // Forward to default implementation
        //
        return super.convertToString(factory, dataType, value);
    }

    @Override
    protected Object createFromString(EFactory eFactory, EDataType eDataType, String value) {
        //
        // Get data type
        //
        Class<?> type = eDataType.getInstanceClass();
        //
        // Only serialize Geometry instances
        //
        if(DataTypes.isGeometry(type)) {
            //
            // Convert hex string to WKB formated byte array
            //
            byte[] b = toByte(value);
            try {
                
                //
                // Convert to Geometry
                //
                return DataBuilder.toGeometry(b);
                
            } catch (ParseException e) {
                //
                // Notify
                //
                LOGGER.log(Level.WARNING, e.getMessage(), e);
                //
                // Try to create an empty geometry of given type
                //
                try {
                    return DataBuilder.toEmptyGeometry(type);
                } catch (ParseException e1) {
                    //
                    // Notify again
                    //
                    LOGGER.log(Level.SEVERE, e1.getMessage(), e1);
                    //
                    // This time, nothing can be done, just return null.
                    //
                    return null;
                }
            }
        }
        //
        // Forward to default implementation
        //
        return super.createFromString(eFactory, eDataType, value);
    }
    
    private static final String toString(byte[] b) {
        //
        // Create a BigInteger using the byte array
        //
        BigInteger bi = new BigInteger(b);
        //
        // Return as hex string
        //
        return bi.toString(32);
    }
    
    private static final byte[] toByte(String s) {
        //
        // Create a BigInteger using the byte array
        //
        BigInteger bi = new BigInteger(s,32);
        //
        // Return as byte array
        //
        return bi.toByteArray();
    }
    

}