/*
 * 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.tuscany.sca.databinding.jaxb;

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;

import javax.xml.namespace.QName;
import javax.xml.ws.WebFault;

import org.apache.tuscany.sca.databinding.ExceptionHandler;
import org.apache.tuscany.sca.interfacedef.DataType;
import org.apache.tuscany.sca.interfacedef.impl.DataTypeImpl;
import org.apache.tuscany.sca.interfacedef.util.XMLType;

/**
 * JAXB implementation of ExceptionHandler
 * 
 * @version $Rev$ $Date$
 */
public class JAXBExceptionHandler implements ExceptionHandler {
    private static final Class[] EMPTY_CLASS_ARRAY = new Class[0];

    /**
     * <ul>
     * <li>WrapperException(String message, FaultBean faultInfo) <br>
     * A constructor where WrapperException is replaced with the name of the
     * generated wrapper exception and FaultBean is replaced by the name of the
     * generated fault bean.
     * <li> WrapperException(String message, FaultBean faultInfo, Throwable
     * cause) <br>
     * A constructor whereWrapperException is replaced with the name of the
     * generated wrapper exception and FaultBean is replaced by the name of the
     * generated fault bean. The last argument, cause, may be used to convey
     * protocol specific fault information
     * </ul>
     */
    public Exception createException(DataType<DataType> exceptionType, String message, Object faultInfo, Throwable cause) {
        Class exceptionClass = exceptionType.getPhysical();
        DataType<?> faultBeanType = exceptionType.getLogical();
        Class faultBeanClass = faultBeanType.getPhysical();
        try {
            Constructor constructor =
                exceptionClass.getConstructor(new Class[] {String.class, faultBeanClass, Throwable.class});
            return (Exception)constructor.newInstance(new Object[] {message, faultInfo, cause});
        } catch (Throwable e) {
            throw new IllegalArgumentException(e);
        }
    }

    public Object getFaultInfo(Exception exception) {
        if (exception == null) {
            return null;
        }
        try {
            Method method = exception.getClass().getMethod("getFaultInfo", EMPTY_CLASS_ARRAY);
            return method.invoke(exception, (Object[])null);
        } catch (Throwable e) {
            throw new IllegalArgumentException(e);
        }
    }

    public DataType<?> getFaultType(DataType exDataType) {
        Class<?> exceptionType  = exDataType.getPhysical();
        WebFault webFault = exceptionType.getAnnotation(WebFault.class);
        if (webFault == null) {
            return null;
        } else {
            QName element = new QName(webFault.targetNamespace(), webFault.name());
            // TODO: Need to determine the fault bean class
            // String faultBean = webFault.faultBean();
            Class faultBeanClass = null;
            try {
                Method method = exceptionType.getMethod("getFaultInfo", EMPTY_CLASS_ARRAY);
                faultBeanClass = method.getReturnType();
            } catch (NoSuchMethodException e) {
                faultBeanClass = null;
            }
            // The logical type of a fault is the QName of the element that the
            // only part in
            // the fault message references
            DataType<XMLType> faultType =
                new DataTypeImpl<XMLType>(JAXBDataBinding.NAME, faultBeanClass, new XMLType(element, null));
            // faultType.setMetadata(ElementInfo.class.getName(), new
            // ElementInfo(element, null));
            return faultType;
        }
    }

}