/*
 * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */

package org.opendaylight.controller.netconf.confignetconfconnector.osgi;

import org.opendaylight.controller.config.yang.store.api.YangStoreService;
import org.opendaylight.controller.netconf.mapping.api.NetconfOperationServiceFactory;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceRegistration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Hashtable;

import static com.google.common.base.Preconditions.checkState;

public class Activator implements BundleActivator, YangStoreServiceTracker.YangStoreTrackerListener {

    private static final Logger logger = LoggerFactory.getLogger(Activator.class);

    private BundleContext context;
    private ServiceRegistration osgiRegistration;
    private ConfigRegistryLookupThread configRegistryLookup = null;

    @Override
    public void start(BundleContext context) throws Exception {
        this.context = context;
        YangStoreServiceTracker tracker = new YangStoreServiceTracker(context, this);
        tracker.open();
    }

    @Override
    public void stop(BundleContext context) throws Exception {
        if (configRegistryLookup != null) {
            configRegistryLookup.interrupt();
        }
    }

    @Override
    public synchronized void onYangStoreAdded(YangStoreService yangStoreService) {
        checkState(configRegistryLookup  == null, "More than one onYangStoreAdded received");
        configRegistryLookup = new ConfigRegistryLookupThread(yangStoreService);
        configRegistryLookup.start();
    }

    @Override
    public synchronized void onYangStoreRemoved() {
        configRegistryLookup.interrupt();
        if (osgiRegistration != null) {
            osgiRegistration.unregister();
        }
        osgiRegistration = null;
        configRegistryLookup = null;
    }

    private class ConfigRegistryLookupThread extends Thread {
        private final YangStoreService yangStoreService;

        private ConfigRegistryLookupThread(YangStoreService yangStoreService) {
            super("config-registry-lookup");
            this.yangStoreService = yangStoreService;
        }

        @Override
        public void run() {
            NetconfOperationServiceFactoryImpl factory = new NetconfOperationServiceFactoryImpl(yangStoreService);
            logger.debug("Registering into OSGi");
            osgiRegistration = context.registerService(new String[]{NetconfOperationServiceFactory.class.getName()}, factory,
                    new Hashtable<String, Object>());
        }
    }
}