/*
 * Copyright (c) 2003-2004, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.bundle.cm;

import org.knopflerfish.service.log.*;

import org.osgi.service.cm.*;
import org.osgi.framework.*;

import java.util.Dictionary;
import java.util.Hashtable;
import java.util.Vector;

/**
 ** This class is responsible for dispatching configurations
 ** to ManagedService(Factories).
 **
 ** It is also responsible for calling <code>ConfigurationPlugins</code>.
 **
 ** @author Per Gustafson
 ** @version 1.0
 **/

final class ConfigurationDispatcher {
  private final static String SERVICE_PID = "service.pid";
  private final static String FACTORY_PID = "service.factoryPid";

  /**
   ** The PluginManager to use.
   **/

  private PluginManager pm;

  /**
   ** One queue per target service.
   **/

  private Hashtable serviceReferenceToTargetService = new Hashtable();
  private Hashtable targetServiceToQueue = new Hashtable();

  /**
   ** Construct a ConfigurationDispatcher given a  
   ** ConfigurationServicesTracker.
   **
   ** @param tracker The ConfigurationServicesTracker to use.
   **/

  ConfigurationDispatcher(PluginManager pm) {
    this.pm = pm;
  }

  public UpdateQueue getQueueFor(ServiceReference sr) {
    synchronized(targetServiceToQueue) {
      Object targetService = serviceReferenceToTargetService.get(sr);
      if(targetService == null) {
        return null;
      } else {
        return (UpdateQueue)targetServiceToQueue.get(targetService);
      }
    }
  }

  public void addQueueFor(ServiceReference sr) {
    synchronized(targetServiceToQueue) {
      Object targetService = serviceReferenceToTargetService.get(sr);
      if(targetService == null) {
        targetService = Activator.bc.getService(sr);
        if(targetService == null) {
          Activator.log.error("Failed getting target service to build new queue for.");
          return;
        }
        serviceReferenceToTargetService.put(sr, targetService);
      }
      if(!targetServiceToQueue.containsKey(targetService)) {
        targetServiceToQueue.put(targetService, new UpdateQueue(pm));
      }
    }
  }

  public void removeQueueFor(ServiceReference sr) {
    synchronized(targetServiceToQueue) {
      Object targetService = serviceReferenceToTargetService.remove(sr);
      if(targetService == null) {
        Activator.log.error("Missing target service for a ServiceReference in removeQueueFor(ServiceReference)");
      } else if(!serviceReferenceToTargetService.contains(targetService)) {
        UpdateQueue uq = (UpdateQueue)targetServiceToQueue.remove(targetService);
        if(uq == null) {
          Activator.log.error("Missing UpdateQueue for a ServiceReference in removeQueueFor(ServiceReference)");
        }
      }
    }
  }

  public void dispatchUpdateFor(ServiceReference sr, String pid, String factoryPid, ConfigurationDictionary cd) {
    UpdateQueue uq = getQueueFor(sr);
    if(uq == null) {
      Activator.log.error("Missing UpdateQueue for " + factoryPid);
      return;
    }
    Update u = new Update(sr, pid, factoryPid, cd);
    
    uq.enqueue(u);
  }
}