/**
 * Licensed to jclouds, Inc. (jclouds) under one or more
 * contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  jclouds 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.jclouds.karaf.chef.cache;

import org.jclouds.chef.ChefService;
import org.jclouds.karaf.cache.BasicCacheProvider;
import org.jclouds.karaf.cache.CacheManager;
import org.jclouds.karaf.cache.CacheProvider;
import org.jclouds.karaf.cache.utils.CacheUtils;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceRegistration;
import org.osgi.util.tracker.ServiceTracker;

import java.util.Properties;

public class Activator implements BundleActivator {

    private ServiceTracker chefServiceTracker;
    private ServiceTracker chefCacheableTracker;

    private ServiceRegistration cacheProviderRegistration;

    private final CacheManager<ChefService> chefCacheManager = new CacheManager<ChefService>();


    /**
     * Called when this bundle is started so the Framework can perform the
     * bundle-specific activities necessary to start this bundle. This method
     * can be used to register services or to allocate any resources that this
     * bundle needs.
     * <p/>
     * <p/>
     * This method must complete and return to its caller in a timely manner.
     *
     * @param context The execution context of the bundle being started.
     * @throws Exception If this method throws an exception, this
     *                   bundle is marked as stopped and the Framework will remove this
     *                   bundle's listeners, unregister all services registered by this
     *                   bundle, and release all services used by this bundle.
     */
    @Override
    public void start(BundleContext context) throws Exception {
        CacheProvider cacheProvider = new BasicCacheProvider();
        cacheProviderRegistration = context.registerService(CacheProvider.class.getName(), cacheProvider, new Properties());


        chefServiceTracker = CacheUtils.createServiceCacheTracker(context, ChefService.class, chefCacheManager);
        chefCacheableTracker = CacheUtils.createCacheableTracker(context, "jclouds.chefservice", chefCacheManager);

        chefServiceTracker.open();
        chefCacheableTracker.open();
        chefCacheManager.init();

    }

    /**
     * Called when this bundle is stopped so the Framework can perform the
     * bundle-specific activities necessary to stop the bundle. In general, this
     * method should undo the work that the <code>BundleActivator.start</code>
     * method started. There should be no active threads that were started by
     * this bundle when this bundle returns. A stopped bundle must not call any
     * Framework objects.
     * <p/>
     * <p/>
     * This method must complete and return to its caller in a timely manner.
     *
     * @param context The execution context of the bundle being stopped.
     * @throws Exception If this method throws an exception, the
     *                   bundle is still marked as stopped, and the Framework will remove
     *                   the bundle's listeners, unregister all services registered by the
     *                   bundle, and release all services used by the bundle.
     */
    @Override
    public void stop(BundleContext context) throws Exception {
        chefCacheManager.destroy();

        if (cacheProviderRegistration != null) {
            cacheProviderRegistration.unregister();
        }
        if (chefServiceTracker != null) {
            chefServiceTracker.close();
        }
        if (chefCacheableTracker != null) {
            chefCacheableTracker.close();
        }
    }
}
