/**
 * 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.cxf.bus.osgi;

import java.util.ArrayList;
import java.util.List;

import org.apache.cxf.bus.blueprint.BlueprintNameSpaceHandlerFactory;
import org.apache.cxf.bus.blueprint.NamespaceHandlerRegisterer;
import org.apache.cxf.bus.extension.Extension;
import org.apache.cxf.bus.extension.ExtensionRegistry;
import org.apache.cxf.common.util.CollectionUtils;
import org.apache.cxf.internal.CXFAPINamespaceHandler;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.Constants;
import org.osgi.framework.ServiceRegistration;
import org.osgi.service.cm.ConfigurationAdmin;
import org.osgi.service.cm.ManagedServiceFactory;
import org.osgi.util.tracker.ServiceTracker;

/**
 * Is called in OSGi on start and stop of the cxf bundle.
 * Manages
 * - CXFBundleListener
 * - Attaching ManagedWorkqueues to config admin service
 * - OsgiBusListener
 * - Blueprint namespaces
 */
public class CXFActivator implements BundleActivator {

    private List<Extension> extensions;
    private ManagedWorkQueueList workQueues;
    private ServiceTracker<ConfigurationAdmin, ConfigurationAdmin> configAdminTracker;
    private CXFExtensionBundleListener cxfBundleListener;
    private ServiceRegistration<ManagedServiceFactory> workQueueServiceRegistration;


    /** {@inheritDoc}*/
    public void start(BundleContext context) throws Exception {
        workQueues = new ManagedWorkQueueList();
        cxfBundleListener = new CXFExtensionBundleListener(context.getBundle().getBundleId());
        context.addBundleListener(cxfBundleListener);
        cxfBundleListener.registerExistingBundles(context);

        configAdminTracker = new ServiceTracker<>(context, ConfigurationAdmin.class, null);
        configAdminTracker.open();
        workQueues.setConfigAdminTracker(configAdminTracker);
        workQueueServiceRegistration = registerManagedServiceFactory(context,
                                                                     ManagedServiceFactory.class,
                                                                     workQueues,
                                                                     ManagedWorkQueueList.FACTORY_PID);

        extensions = new ArrayList<>();
        extensions.add(createOsgiBusListenerExtension(context));
        extensions.add(createManagedWorkQueueListExtension(workQueues));
        ExtensionRegistry.addExtensions(extensions);

        BlueprintNameSpaceHandlerFactory factory = new BlueprintNameSpaceHandlerFactory() {

            @Override
            public Object createNamespaceHandler() {
                return new CXFAPINamespaceHandler();
            }
        };
        NamespaceHandlerRegisterer.register(context, factory,
                                            "http://cxf.apache.org/blueprint/core",
                                            "http://cxf.apache.org/configuration/beans",
                                            "http://cxf.apache.org/configuration/parameterized-types",
                                            "http://cxf.apache.org/configuration/security",
                                            "http://schemas.xmlsoap.org/wsdl/",
                                            "http://www.w3.org/2005/08/addressing",
                                            "http://schemas.xmlsoap.org/ws/2004/08/addressing");

    }

    private <T> ServiceRegistration<T> registerManagedServiceFactory(BundleContext context,
                                                                     Class<T> serviceClass,
                                                                     T service,
                                                                     String servicePid) {
        return context.registerService(serviceClass, service, 
                                       CollectionUtils.singletonDictionary(Constants.SERVICE_PID, servicePid));
    }

    private Extension createOsgiBusListenerExtension(BundleContext context) {
        Extension busListener = new Extension(OSGIBusListener.class);
        busListener.setArgs(new Object[] {context});
        return busListener;
    }

    private static Extension createManagedWorkQueueListExtension(final ManagedWorkQueueList workQueues) {
        return new Extension(ManagedWorkQueueList.class) {
            
            @Override
            public Object getLoadedObject() {
                return workQueues;
            }

            @Override
            public Extension cloneNoObject() {
                return this;
            }
        };
    }

    /** {@inheritDoc}*/
    public void stop(BundleContext context) throws Exception {
        context.removeBundleListener(cxfBundleListener);
        cxfBundleListener.shutdown();
        workQueues.shutDown();
        workQueueServiceRegistration.unregister();
        configAdminTracker.close();
        ExtensionRegistry.removeExtensions(extensions);
    }

}