/**
 * 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.dosgi.dsw;

import java.util.ArrayList;
import java.util.Dictionary;
import java.util.Hashtable;
import java.util.List;
import java.util.Map;

import org.apache.cxf.Bus;
import org.apache.cxf.BusFactory;
import org.apache.cxf.dosgi.dsw.decorator.ServiceDecorator;
import org.apache.cxf.dosgi.dsw.decorator.ServiceDecoratorBundleListener;
import org.apache.cxf.dosgi.dsw.decorator.ServiceDecoratorImpl;
import org.apache.cxf.dosgi.dsw.handlers.ConfigTypeHandlerFactory;
import org.apache.cxf.dosgi.dsw.handlers.HttpServiceManager;
import org.apache.cxf.dosgi.dsw.qos.DefaultIntentMapFactory;
import org.apache.cxf.dosgi.dsw.qos.IntentManager;
import org.apache.cxf.dosgi.dsw.qos.IntentManagerImpl;
import org.apache.cxf.dosgi.dsw.qos.IntentMap;
import org.apache.cxf.dosgi.dsw.qos.IntentTracker;
import org.apache.cxf.dosgi.dsw.service.RemoteServiceAdminCore;
import org.apache.cxf.dosgi.dsw.service.RemoteServiceadminFactory;
import org.apache.cxf.dosgi.dsw.util.Utils;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleListener;
import org.osgi.framework.Constants;
import org.osgi.framework.ServiceRegistration;
import org.osgi.service.cm.ConfigurationException;
import org.osgi.service.cm.ManagedService;
import org.osgi.service.remoteserviceadmin.RemoteServiceAdmin;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

// registered as spring bean -> start / stop called accordingly
public class Activator implements ManagedService, BundleActivator {

    private static final Logger LOG = LoggerFactory.getLogger(Activator.class);
    private static final int DEFAULT_INTENT_TIMEOUT = 30000;
    private static final String CONFIG_SERVICE_PID = "cxf-dsw";
    private ServiceRegistration rsaFactoryReg;
    private ServiceRegistration decoratorReg;
    private IntentTracker intentTracker;
    private HttpServiceManager httpServiceManager;
    private BundleContext bc;
    private BundleListener bundleListener;

    public void start(BundleContext bundlecontext) throws Exception {
        LOG.debug("RemoteServiceAdmin Implementation is starting up");
        this.bc = bundlecontext;
        // Disable the fast infoset as it's not compatible (yet) with OSGi
        System.setProperty("org.apache.cxf.nofastinfoset", "true");
        init(new Hashtable<String, Object>());
        registerManagedService(bc);
    }

    private synchronized void init(Map<String, Object> config) {
        String httpBase = (String) config.get(org.apache.cxf.dosgi.dsw.Constants.HTTP_BASE);
        String cxfServletAlias = (String) config.get(org.apache.cxf.dosgi.dsw.Constants.CXF_SERVLET_ALIAS);

        IntentMap intentMap = new IntentMap(new DefaultIntentMapFactory().create());
        intentTracker = new IntentTracker(bc, intentMap);
        intentTracker.open();
        IntentManager intentManager = new IntentManagerImpl(intentMap, DEFAULT_INTENT_TIMEOUT);
        httpServiceManager = new HttpServiceManager(bc, httpBase, cxfServletAlias);
        ConfigTypeHandlerFactory configTypeHandlerFactory
            = new ConfigTypeHandlerFactory(bc, intentManager, httpServiceManager);
        RemoteServiceAdminCore rsaCore = new RemoteServiceAdminCore(bc, configTypeHandlerFactory);
        RemoteServiceadminFactory rsaf = new RemoteServiceadminFactory(rsaCore);
        Dictionary<String, Object> props = new Hashtable<String, Object>();
        String[] supportedIntents = intentMap.keySet().toArray(new String[] {});
        props.put("remote.intents.supported", supportedIntents);
        props.put("remote.configs.supported",
                  obtainSupportedConfigTypes(configTypeHandlerFactory.getSupportedConfigurationTypes()));
        LOG.info("Registering RemoteServiceAdminFactory...");
        rsaFactoryReg = bc.registerService(RemoteServiceAdmin.class.getName(), rsaf, props);
        ServiceDecoratorImpl serviceDecorator = new ServiceDecoratorImpl();
        bundleListener = new ServiceDecoratorBundleListener(serviceDecorator);
        bc.addBundleListener(bundleListener);
        decoratorReg = bc.registerService(ServiceDecorator.class.getName(), serviceDecorator, null);
    }

    // The CT sometimes uses the first element returned to register a service, but
    // does not provide any additional configuration.
    // Return the configuration type that works without additional configuration as the first in the list.
    private String[] obtainSupportedConfigTypes(List<String> types) {
        List<String> l = new ArrayList<String>(types);
        if (l.contains(org.apache.cxf.dosgi.dsw.Constants.WS_CONFIG_TYPE)) {
            // make sure its the first element...
            l.remove(org.apache.cxf.dosgi.dsw.Constants.WS_CONFIG_TYPE);
            l.add(0, org.apache.cxf.dosgi.dsw.Constants.WS_CONFIG_TYPE);
        }
        return l.toArray(new String[] {});
    }

    private void registerManagedService(BundleContext bundlecontext) {
        Dictionary<String, String> props = new Hashtable<String, String>();
        props.put(Constants.SERVICE_PID, CONFIG_SERVICE_PID);
        // No need to store the registration. Will be unregistered in stop by framework
        bundlecontext.registerService(ManagedService.class.getName(), this, props);
    }

    public void stop(BundleContext context) throws Exception {
        LOG.debug("RemoteServiceAdmin Implementation is shutting down now");
        bc.removeBundleListener(bundleListener);
        intentTracker.close();
        // This also triggers the unimport and unexport of the remote services
        rsaFactoryReg.unregister();
        decoratorReg.unregister();
        httpServiceManager.close();
        httpServiceManager = null;
        intentTracker = null;
        rsaFactoryReg = null;
        decoratorReg = null;
        shutdownCXFBus();
    }

    /**
     * Causes also the shutdown of the embedded HTTP server
     */
    private void shutdownCXFBus() {
        Bus b = BusFactory.getDefaultBus();
        if (b != null) {
            LOG.debug("Shutting down the CXF Bus");
            b.shutdown(true);
        }
    }

    @SuppressWarnings({ "rawtypes", "unchecked" })
    public synchronized void updated(Dictionary config) throws ConfigurationException {
        LOG.debug("RemoteServiceAdmin Implementation configuration is updated with {}", config);
        if (config != null) {
            try {
                bc.removeBundleListener(bundleListener);
                intentTracker.close();
                // This also triggers the unimport and unexport of the remote services
                rsaFactoryReg.unregister();
                decoratorReg.unregister();
                httpServiceManager.close();
                httpServiceManager = null;
                intentTracker = null;
                rsaFactoryReg = null;
                decoratorReg = null;
            } catch (Exception e) {
                LOG.error(e.getMessage(), e);
            }
            init(Utils.toMap(config));
        }
    }

}