/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2002-2010, 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.se.v1_1.bindings;

import org.geotools.se.v1_1.SE;
import org.geotools.xml.*;
import org.opengis.filter.FilterFactory;
import org.opengis.filter.expression.Expression;
import org.opengis.filter.expression.Function;

import javax.xml.namespace.QName;

/**
 * Binding object for the element http://www.opengis.net/se:Substring.
 * 
 * <p>
 * 
 * <pre>
 *  <code>
 *  <xsd:element name="Substring" substitutionGroup="se:Function" type="se:SubstringType">
 *      <xsd:annotation>
 *          <xsd:documentation>
 *  Returns substrings.
 *               </xsd:documentation>
 *      </xsd:annotation>
 *  </xsd:element> 
 * 	
 *   </code>
 * </pre>
 * 
 * <pre>
 *       <code>
 *  <xsd:complexType name="SubstringType">
 *      <xsd:complexContent>
 *          <xsd:extension base="se:FunctionType">
 *              <xsd:sequence>
 *                  <xsd:element ref="se:StringValue"/>
 *                  <xsd:element minOccurs="0" ref="se:Position"/>
 *                  <xsd:element minOccurs="0" ref="se:Length"/>
 *              </xsd:sequence>
 *          </xsd:extension>
 *      </xsd:complexContent>
 *  </xsd:complexType> 
 *              
 *        </code>
 * </pre>
 * 
 * </p>
 * 
 * @generated
 *
 * @source $URL: http://svn.osgeo.org/geotools/trunk/modules/extension/xsd/xsd-sld/src/main/java/org/geotools/se/v1_1/bindings/SubstringBinding.java $
 */
public class SubstringBinding extends AbstractComplexBinding {

    FilterFactory filterFactory;
    
    public SubstringBinding(FilterFactory filterFactory) {
        this.filterFactory = filterFactory;
    }
    
    /**
     * @generated
     */
    public QName getTarget() {
        return SE.Substring;
    }

    /**
     * <!-- begin-user-doc --> <!-- end-user-doc -->
     * 
     * @generated modifiable
     */
    public Class getType() {
        return Expression.class;
    }

    /**
     * <!-- begin-user-doc --> <!-- end-user-doc -->
     * 
     * @generated modifiable
     */
    public Object parse(ElementInstance instance, Node node, Object value) throws Exception {
        //<xsd:element ref="se:StringValue"/>
        Expression string = (Expression) node.getChildValue("StringValue");
        
        //<xsd:element minOccurs="0" ref="se:Position"/>
        Expression position = (Expression) node.getChildValue("Position");
        
        //function is one based
        position = filterFactory.subtract(position, filterFactory.literal(1));
        
        //<xsd:element minOccurs="0" ref="se:Length"/>
        Expression length = (Expression) node.getChildValue("Length");

        //our strSubstring function works with begin,end rather than begin,length
        Expression end = filterFactory.add(position, length);
        
        return filterFactory.function("strSubstring", string, position, end);
    }

}