package org.geotools.filter.function.string;

/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 * 
 *    (C) 2005-2008, 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.
 */

//this code is autogenerated - you shouldnt be modifying it!
import java.util.Arrays;
import java.util.List;

import org.geotools.filter.FunctionImpl;
import org.opengis.filter.capability.FunctionName;
import org.opengis.filter.expression.Expression;
import org.opengis.filter.expression.ExpressionVisitor;

/**
 * The function concatenates strings.
 * <p>
 * It is used to create concatenated strings as arguments of functions.
 * <p>
 * Implementation of Concatenate as defined by SE1.1.
 * <p>
 * 
 * @author Jody Garnett (Refractions Research, Inc.)
 *
 * @source $URL$
 */
public class ConcatenateFunction extends FunctionImpl {

    /**
     * Make the instance of FunctionName available in
     * a consistent spot.
     */
    public static final FunctionName NAME = new Name();

    /**
     * Describe how this function works.
     * (should be available via FactoryFinder lookup...)
     */
    public static class Name implements FunctionName {

        public int getArgumentCount() {
            return 2; // indicating unbounded, 2 minimum
        }

        public List<String> getArgumentNames() {
            return Arrays.asList(new String[]{
                        "text 1",
                        "text 2",
                        "text 3"
                    });
        }

        public String getName() {
            return "Concatenate";
        }
    };
    
    public ConcatenateFunction() {        
    }
    
    @Override
    public String getName() {
    	return NAME.getName();
    }

    public int getArgCount() {
        return 2; // treat this as minimum argument count
    }

    public Object evaluate(Object feature) {
        StringBuffer text = new StringBuffer();
        for( Expression expression: (List<Expression>) getParameters() ){
        	try {
        		String str = (String) expression.evaluate(feature, String.class);
        		text.append( str );
        	}
        	catch( Exception couldNotCompute){
        		// log me please
        	}
        }
        return text.toString();
    }
}