/**
 *
 * 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.openejb.server.cxf.ejb;

import org.apache.cxf.Bus;
import org.apache.cxf.binding.soap.SoapMessage;
import org.apache.cxf.binding.soap.interceptor.MustUnderstandInterceptor;
import org.apache.cxf.endpoint.Endpoint;
import org.apache.cxf.interceptor.AbstractInDatabindingInterceptor;
import org.apache.cxf.interceptor.Interceptor;
import org.apache.cxf.interceptor.InterceptorChain;
import org.apache.cxf.interceptor.OutgoingChainInterceptor;
import org.apache.cxf.interceptor.ServiceInvokerInterceptor;
import org.apache.cxf.jaxws.handler.logical.LogicalHandlerInInterceptor;
import org.apache.cxf.jaxws.handler.soap.SOAPHandlerInterceptor;
import org.apache.cxf.jaxws.interceptors.HolderInInterceptor;
import org.apache.cxf.jaxws.interceptors.WrapperClassInInterceptor;
import org.apache.cxf.jaxws.support.JaxWsEndpointImpl;
import org.apache.cxf.message.Exchange;
import org.apache.cxf.message.Message;
import org.apache.cxf.phase.PhaseInterceptorChain;
import org.apache.cxf.phase.PhaseManager;
import org.apache.cxf.service.Service;
import org.apache.cxf.staxutils.StaxUtils;
import org.apache.openejb.server.ServerRuntimeException;
import org.apache.openejb.util.LogCategory;
import org.apache.openejb.util.Logger;

import javax.interceptor.AroundInvoke;
import javax.interceptor.InvocationContext;
import javax.xml.soap.SOAPMessage;
import javax.xml.stream.XMLStreamReader;
import javax.xml.transform.dom.DOMSource;
import javax.xml.ws.Binding;
import java.lang.reflect.Method;
import java.util.List;

public class EjbInterceptor {
    private static final Logger log = Logger.getInstance(LogCategory.CXF, EjbInterceptor.class);

    private Exchange exchange;
    private Bus bus;
    private List<Object> params;
    private Method method;

    public EjbInterceptor(List<Object> params, Method method, Bus bus, Exchange exchange) {
        this.params = params;
        this.method = method;
        this.bus = bus;
        this.exchange = exchange;
    }

    private static void copyDataBindingInterceptors(PhaseInterceptorChain newChain, InterceptorChain oldChain) {
        for (Interceptor interceptor : oldChain) {
            if (interceptor instanceof AbstractInDatabindingInterceptor) {
                log.debug("Added data binding interceptor: " + interceptor);
                newChain.add(interceptor);
            }
        }
    }

    @AroundInvoke
    public Object intercept(InvocationContext context) throws Exception {
        Endpoint endpoint = this.exchange.get(Endpoint.class);
        Service service = endpoint.getService();
        Binding binding = ((JaxWsEndpointImpl) endpoint).getJaxwsBinding();

        this.exchange.put(InvocationContext.class, context);

        if (binding.getHandlerChain() == null || binding.getHandlerChain().isEmpty()) {
            // no handlers so let's just directly invoke the bean
            log.debug("No handlers found.");

            EjbMethodInvoker invoker = (EjbMethodInvoker) service.getInvoker();
            return invoker.directEjbInvoke(this.exchange, this.method, this.params);

        } else {
            // have handlers so have to run handlers now and redo data binding
            // as handlers can change the soap message
            log.debug("Handlers found.");

            Message inMessage = exchange.getInMessage();
            PhaseInterceptorChain chain = new PhaseInterceptorChain(bus.getExtension(PhaseManager.class).getInPhases());

            chain.setFaultObserver(endpoint.getOutFaultObserver());

            /*
             * Since we have to re-do data binding and the XMLStreamReader
             * contents are already consumed by prior data binding step
             * we have to reinitialize the XMLStreamReader from the SOAPMessage
             * created by SAAJInInterceptor.
             */
            if (inMessage instanceof SoapMessage) {
                try {
                    reserialize((SoapMessage) inMessage);
                } catch (Exception e) {
                    throw new ServerRuntimeException("Failed to reserialize soap message", e);
                }
            } else {
                // TODO: how to handle XML/HTTP binding?
            }

            this.exchange.setOutMessage(null);

            // install default interceptors
            chain.add(new ServiceInvokerInterceptor());
            chain.add(new OutgoingChainInterceptor());

            // See http://cwiki.apache.org/CXF20DOC/interceptors.html
            // install Holder and Wrapper interceptors
            chain.add(new WrapperClassInInterceptor());
            chain.add(new HolderInInterceptor());

            // install interceptors for handler processing
            chain.add(new MustUnderstandInterceptor());
            chain.add(new LogicalHandlerInInterceptor(binding));
            chain.add(new SOAPHandlerInterceptor(binding));

            // install data binding interceptors
            copyDataBindingInterceptors(chain, inMessage.getInterceptorChain());

            InterceptorChain oldChain = inMessage.getInterceptorChain();
            inMessage.setInterceptorChain(chain);
            try {
                chain.doIntercept(inMessage);
            } finally {
                inMessage.setInterceptorChain(oldChain);
            }

            // TODO: the result should be deserialized from SOAPMessage
            Object result = getResult();

            return result;
        }
    }

    private Object getResult() {
        Message outMessage = this.exchange.getOutMessage();
        if (outMessage == null) {
            return null;
        } else {
            List<?> result = outMessage.getContent(List.class);
            if (result == null) {
                return outMessage.get(Object.class);
            } else if (result.isEmpty()) {
                return null;
            } else {
                return result.get(0);
            }
        }
    }

    private void reserialize(SoapMessage message) throws Exception {
        SOAPMessage soapMessage = message.getContent(SOAPMessage.class);
        if (soapMessage == null) {
            return;
        }

        DOMSource bodySource = new DOMSource(soapMessage.getSOAPPart());
        XMLStreamReader xmlReader = StaxUtils.createXMLStreamReader(bodySource);
        message.setContent(XMLStreamReader.class, xmlReader);
    }
}
