/*
 * 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.felix.eventadmin.bridge.configuration.impl;

import java.util.Arrays;
import java.util.Dictionary;
import java.util.Hashtable;

import org.osgi.framework.BundleContext;
import org.osgi.framework.Constants;
import org.osgi.framework.ServiceReference;
import org.osgi.service.cm.ConfigurationAdmin;
import org.osgi.service.cm.ConfigurationEvent;
import org.osgi.service.cm.ConfigurationListener;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventAdmin;
import org.osgi.service.event.EventConstants;

/**
 * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
 */
public class ConfigurationEventToEventAdminBridge implements
    ConfigurationListener
{
    private final BundleContext m_context;

    public ConfigurationEventToEventAdminBridge(final BundleContext context)
    {
        m_context = context;

        m_context.registerService(ConfigurationListener.class, this,
            null);
    }

    @Override
    public void configurationEvent(final ConfigurationEvent event)
    {
        final ServiceReference<EventAdmin> ref = m_context.getServiceReference(EventAdmin.class);

        if (null != ref)
        {
            final EventAdmin eventAdmin = m_context.getService(ref);

            if (null != eventAdmin)
            {
                try
                {
                    final String topic;

                    switch (event.getType())
                    {
                        case ConfigurationEvent.CM_UPDATED:
                            topic = "org/osgi/service/cm/ConfigurationEvent/CM_UPDATED";
                            break;
                        case ConfigurationEvent.CM_DELETED:
                            topic = "org/osgi/service/cm/ConfigurationEvent/CM_DELETED";
                            break;
                        case ConfigurationEvent.CM_LOCATION_CHANGED:
                            topic = "org/osgi/service/cm/ConfigurationEvent/CM_LOCATION_CHANGED";
                            break;
                        default:
                            return;
                    }

                    final Dictionary<String, Object> properties = new Hashtable<String, Object>();

                    if (null != event.getFactoryPid())
                    {
                        properties.put("cm.factoryPid", event.getFactoryPid());
                    }

                    properties.put("cm.pid", event.getPid());

                    final ServiceReference<ConfigurationAdmin> eventRef = event.getReference();

                    if (null == eventRef)
                    {
                        throw new IllegalArgumentException(
                            "ConfigurationEvent.getReference() may not be null");
                    }

                    properties.put(EventConstants.SERVICE, eventRef);

                    properties.put(EventConstants.SERVICE_ID, eventRef.getProperty(
                        EventConstants.SERVICE_ID));

                    final Object objectClass = eventRef.getProperty(
                        Constants.OBJECTCLASS);

                    if(!(objectClass instanceof String[])
                        || !Arrays.asList((String[]) objectClass).contains(
                        ConfigurationAdmin.class.getName()))
                    {
                        throw new IllegalArgumentException(
                            "Bad objectclass: " + objectClass);
                    }

                    properties.put(EventConstants.SERVICE_OBJECTCLASS, objectClass);

                    properties.put(EventConstants.SERVICE_PID, eventRef.getProperty(
                        EventConstants.SERVICE_PID));

                    eventAdmin.postEvent(new Event(topic, properties));
                }
                finally
                {
                    m_context.ungetService(ref);
                }
            }
        }
    }
}