/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.cocoon.portal.aspect.impl;

import java.lang.reflect.Constructor;

import org.apache.cocoon.portal.aspect.AspectDescription;
import org.apache.cocoon.util.ClassUtils;



/**
 * Utility class for aspects
 * 
 * @author <a href="mailto:cziegeler@s-und-n.de">Carsten Ziegeler</a>
 * 
 * @version CVS $Id$
 */
public class AspectUtil { 

    /**
     * Create a new instance
     */
    public static Object createNewInstance(AspectDescription desc) {
        try {
            Class clazz = ClassUtils.loadClass(desc.getClassName());
            if ( clazz.getName().startsWith("java.lang.")) {
                Constructor constructor = clazz.getConstructor(new Class[] {String.class});
                String value = (desc.getDefaultValue() == null ? "0" : desc.getDefaultValue());
                return constructor.newInstance(new String[] {value});
            }
            if ( desc.getDefaultValue() != null ) {
                Constructor constructor = clazz.getConstructor(new Class[] {String.class});
                return constructor.newInstance(new String[] {desc.getDefaultValue()});
            }
            return clazz.newInstance();
        } catch (Exception ignore) {
            return null;
        }
    }
    
    public static Object convert(AspectDescription desc, Object value) {
        try {
            Class clazz = ClassUtils.loadClass(desc.getClassName());
            if ( clazz.getName().startsWith("java.lang.")) {
                if ( !clazz.equals(value.getClass())) {
                    Constructor constructor = clazz.getConstructor(new Class[] {String.class});
                    return constructor.newInstance(new String[] {value.toString()});
                }
                return value;
            }
            if ( !value.getClass().equals(clazz) ) {
                // FIXME - this is catch by "ignore"
                throw new RuntimeException("Class of aspect doesn't match description.");
            }
            return value;
        } catch (Exception ignore) {
            // if we can't convert, well we don't do it :)
            return value;
        }        
    }
}