/*******************************************************************************
    * Copyright (c) 2007, 2014 Massimiliano Ziccardi
    *
    * Licensed 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.slf4j.impl;
  
  import org.osgi.framework.BundleContext;
  import org.osgi.framework.InvalidSyntaxException;
  import org.osgi.framework.ServiceEvent;
  import org.osgi.framework.ServiceListener;
  import org.osgi.framework.ServiceReference;
  import org.osgi.service.log.LogService;
  import org.slf4j.ILoggerFactory;
  import org.slf4j.Logger;
  
  public class OSGILogFactory implements ILoggerFactory
  {
      static private OSGiLogger s_logger = new OSGiLogger();
  
      private static BundleContext s_context = null;
      private static ServiceReference s_serviceref = null;
      private static LogService s_logservice = null;
  
      private static ServiceListener s_servlistener = new ServiceListener() {
          public void serviceChanged(final ServiceEvent event)
          {
              LogService ls =
                      (LogService) s_context.getService(event
                              .getServiceReference());
              if (ls != null)
              {
                  if (event.getType() == ServiceEvent.REGISTERED)
                  {
                      OSGILogFactory.setLogService(ls);
  
                  }
                  else if (event.getType() == ServiceEvent.UNREGISTERING)
                  {
                      if (ls.equals(s_logservice))
                      {
                          OSGILogFactory.setLogService(null);
  
                          // Try to find another log service as a replacement for
                          // our loss
                          ServiceReference ref =
                                  s_context.getServiceReference(LogService.class
                                          .getName());
                          if (ref != null)
                          {
                              s_logservice =
                                      (LogService) s_context.getService(ref);
                          }
                      }
                  }
              }
          }
      };
  
      public static void initOSGI(final BundleContext context)
      {
          initOSGI(context, null);
      }
  
      public static void
      initOSGI(final BundleContext context, final ServiceReference servref)
      {
          s_context = context;
          s_serviceref = servref;
  
          try {
              String filter = "(objectclass=" + LogService.class.getName() + ")";
              context.addServiceListener(s_servlistener, filter);
          } catch (InvalidSyntaxException e) {
              e.printStackTrace();
          }
  
          ServiceReference ref =
                  context.getServiceReference(LogService.class.getName());
          if (ref != null)
          {
              s_logservice = (LogService) context.getService(ref);
          }
      }
  
      static public LogService getLogService()
      {
          return s_logservice;
      }
 
     static public ServiceReference getServiceReference()
     {
         return s_serviceref;
     }
 
     static public void setLogService(final LogService logservice)
     {
         s_logservice = logservice;
     }
 
     static public void setServiceReference(final ServiceReference ref)
     {
         s_serviceref = ref;
     }
 
     public Logger getLogger(final String arg0) {
         return s_logger;
     }
 
 }