/*
 * 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.binding.local;

import org.apache.tuscany.sca.assembly.Endpoint;
import org.apache.tuscany.sca.core.ExtensionPointRegistry;
import org.apache.tuscany.sca.core.UtilityExtensionPoint;
import org.apache.tuscany.sca.databinding.Mediator;
import org.apache.tuscany.sca.interfacedef.Compatibility;
import org.apache.tuscany.sca.interfacedef.InterfaceContract;
import org.apache.tuscany.sca.interfacedef.InterfaceContractMapper;
import org.apache.tuscany.sca.interfacedef.Operation;
import org.apache.tuscany.sca.invocation.InvocationChain;
import org.apache.tuscany.sca.invocation.Invoker;
import org.apache.tuscany.sca.provider.EndpointReferenceProvider;
import org.apache.tuscany.sca.runtime.RuntimeComponent;
import org.apache.tuscany.sca.runtime.RuntimeComponentReference;
import org.apache.tuscany.sca.runtime.RuntimeComponentService;
import org.apache.tuscany.sca.runtime.RuntimeEndpoint;
import org.apache.tuscany.sca.runtime.RuntimeEndpointReference;
import org.oasisopen.sca.ServiceUnavailableException;

/**
 * The Local binding reference binding provider
 */
public class LocalReferenceBindingProvider implements EndpointReferenceProvider {

    private RuntimeEndpointReference endpointReference;
    private RuntimeComponent component;
    private RuntimeComponentReference reference;
    private LocalBinding binding;

    private Mediator mediator;
    private InterfaceContractMapper interfaceContractMapper;

    public LocalReferenceBindingProvider(ExtensionPointRegistry extensionPoints, RuntimeEndpointReference endpointReference) {
        this.endpointReference = endpointReference;
        this.component = (RuntimeComponent)endpointReference.getComponent();
        this.reference = (RuntimeComponentReference)endpointReference.getReference();
        this.binding = (LocalBinding)endpointReference.getBinding();

        UtilityExtensionPoint utilities = extensionPoints.getExtensionPoint(UtilityExtensionPoint.class);
        this.mediator = utilities.getUtility(Mediator.class);
        this.interfaceContractMapper = utilities.getUtility(InterfaceContractMapper.class);
    }

    public InterfaceContract getBindingInterfaceContract() {
        // Check if there is a target
        RuntimeEndpoint endpoint = (RuntimeEndpoint)endpointReference.getTargetEndpoint();
        if (endpoint != null) {
            return endpoint.getComponentTypeServiceInterfaceContract();
        } else {
            return endpointReference.getComponentTypeReferenceInterfaceContract();
        }
    }

    public boolean supportsOneWayInvocation() {
        return false;
    }

    private Invoker getInvoker(RuntimeEndpointReference epr, Operation operation) {
        Endpoint target = epr.getTargetEndpoint();
        if (target != null) {
            RuntimeComponentService service = (RuntimeComponentService)target.getService();
            if (service != null) { // not a callback wire
                InvocationChain chain = ((RuntimeEndpoint)target).getInvocationChain(operation);

                boolean passByValue = false;
                Operation targetOp = chain.getTargetOperation();
                if (!operation.getInterface().isRemotable()) {
                    if (interfaceContractMapper.isCompatibleByReference(operation, targetOp, Compatibility.SUBSET)) {
                        passByValue = false;
                    }
                } else {
                    boolean allowsPBR = false;
                    if (allowsPBR && interfaceContractMapper.isCompatibleByReference(operation,
                                                                                     targetOp,
                                                                                     Compatibility.SUBSET)) {
                        passByValue = false;
                    } else if (interfaceContractMapper.isCompatibleByValue(operation, targetOp, Compatibility.SUBSET)) {
                        passByValue = true;
                    }
                }
                // it turns out that the chain source and target operations are the same, and are the operation 
                // from the target, not sure if thats by design or a bug. The SCA binding invoker needs to know 
                // the source and target class loaders so pass in the real source operation in the constructor 
                return chain == null ? null : new LocalBindingInvoker(chain, operation, mediator, passByValue, epr);
            }
        }
        return null;
    }

    public Invoker createInvoker(Operation operation) {
        Invoker invoker = getInvoker(endpointReference, operation);
        if (invoker == null) {
            throw new ServiceUnavailableException(
                                                  "Unable to create SCA binding invoker for local target " + component
                                                      .getName()
                                                      + " reference "
                                                      + reference.getName()
                                                      + " (bindingURI="
                                                      + binding.getURI()
                                                      + " operation="
                                                      + operation.getName()
                                                      + ")");
        }
        return invoker;
    }

    public void start() {
    }

    public void stop() {
    }

    public void configure() {
    }
}