/**
 *
 *  Copyright 2005 The Apache Software Foundation or its licensors, as applicable.
 *
 *  Licensed 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.container.rhino.context;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Proxy;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.tuscany.container.rhino.rhino.RhinoScript;
import org.apache.tuscany.container.rhino.rhino.RhinoScriptInstance;
import org.apache.tuscany.core.context.AtomicContext;
import org.apache.tuscany.core.context.CoreRuntimeException;
import org.apache.tuscany.core.context.QualifiedName;
import org.apache.tuscany.core.context.TargetException;
import org.apache.tuscany.core.context.event.InstanceCreated;
import org.apache.tuscany.core.context.impl.AbstractContext;
import org.apache.tuscany.core.extension.ExternalServiceInvoker;
import org.apache.tuscany.core.wire.ProxyCreationException;
import org.apache.tuscany.core.wire.SourceWireFactory;
import org.apache.tuscany.core.wire.TargetWireFactory;
import org.apache.tuscany.core.wire.WireFactory;
import org.osoa.sca.ServiceRuntimeException;

public class CopyOfJavaScriptComponentContext extends AbstractContext implements AtomicContext {

    private RhinoScript rhinoScript;

    private Map<String, Object> properties;

    private List<SourceWireFactory> sourceProxyFactories;

    private Map<String, TargetWireFactory> targetProxyFactories;

    public CopyOfJavaScriptComponentContext(String name, Map<String, Object> properties, List<SourceWireFactory> sourceProxyFactories,
            Map<String, TargetWireFactory> targetProxyFactories, RhinoScript rhinoScript) {
        super(name);
        this.properties = properties;
        this.rhinoScript = rhinoScript;
        this.sourceProxyFactories = sourceProxyFactories;
        this.targetProxyFactories = targetProxyFactories;
    }

    public Object getInstance(QualifiedName qName) throws TargetException {
        return getInstance(qName, true);
    }

    public void init() throws TargetException {
        getInstance(null, false);
    }

    public void destroy() throws TargetException {

    }

    private synchronized Object getInstance(QualifiedName qName, boolean notify) throws TargetException {
        String portName = qName.getPortName();
        WireFactory targetFactory;
        if (portName != null) {
            targetFactory = targetProxyFactories.get(portName);
        } else {
            // FIXME The port name is null here, either locateService needs more information (the expected interface) to
            // select the correct port, or we need to return a factory that matches the whole set of services exposed by
            // the component.
            targetFactory = targetProxyFactories.values().iterator().next();
        }
        if (targetFactory == null) {
            TargetException e = new TargetException("Target service not found");
            e.setIdentifier(qName.getPortName());
            e.addContextName(getName());
            throw e;
        }
        try {
            Object proxy = targetFactory.createProxy(); // createProxy(new Class[] { iface });
            if (notify) {
                publish(new InstanceCreated(this));
            }
            return proxy;
        } catch (ProxyCreationException e) {
            TargetException te = new TargetException("Error returning target", e);
            e.setIdentifier(qName.getPortName());
            e.addContextName(getName());
            throw te;
        }
    }

    public Object getTargetInstance() throws TargetException {
        Map<String, Object> contexts = createServiceReferences();
        contexts.putAll(properties);

        final RhinoScriptInstance rhinoScriptInstance = rhinoScript.createRhinoScriptInstance(contexts);

        ExternalServiceInvoker esi = new ExternalServiceInvoker() {
            public Object invoke(String methodName, Object[] args) {
                return rhinoScriptInstance.invokeFunction(methodName, args);
            }
        };

        return esi;
    }

    /**
     * Creates a map containing any ServiceReferences
     */
    private Map<String, Object> createServiceReferences() {
        try {
            Map<String, Object> context = new HashMap<String, Object>();
            for (SourceWireFactory proxyFactory : sourceProxyFactories) {
                Object referenceProxy = createReferenceProxy(proxyFactory);
                context.put(proxyFactory.getConfiguration().getReferenceName(), referenceProxy);
            }
            return context;
        } catch (ProxyCreationException e) {
            throw new ServiceRuntimeException(e);
        }
    }

    private Object createReferenceProxy(SourceWireFactory proxyFactory) throws ProxyCreationException {
        Object proxy = proxyFactory.createProxy();
        Class proxyClass = proxy.getClass();
        if (Proxy.isProxyClass(proxyClass)) {
            Class[] ifaces = proxyClass.getInterfaces();
            Class[] newIfaces = new Class[ifaces.length+1];
            System.arraycopy(ifaces,0,newIfaces,0,ifaces.length);
            newIfaces[ifaces.length] = E4XReference.class;
            InvocationHandler ih = Proxy.getInvocationHandler(proxy);
            proxy = Proxy.newProxyInstance(proxyClass.getClassLoader(), newIfaces, ih);
        }
        return proxy;
    }
    
    interface E4XReference {
        public Object process(Object xml);
    }

    public boolean isEagerInit() {
        return false;
    }

    public boolean isDestroyable() {
        return false;
    }

    public void start() throws CoreRuntimeException {
    }

    public void stop() throws CoreRuntimeException {
    }

}