//
   //  ========================================================================
   //  Copyright (c) 1995-2015 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  All rights reserved. This program and the accompanying materials
   //  are made available under the terms of the Eclipse Public License v1.0
   //  and Apache License v2.0 which accompanies this distribution.
   //
   //      The Eclipse Public License is available at
  //      http://www.eclipse.org/legal/epl-v10.html
  //
  //      The Apache License v2.0 is available at
  //      http://www.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.websocket.servlet;
  
  import java.io.IOException;
  import java.util.Iterator;
  import java.util.ServiceLoader;
  
  import javax.servlet.ServletContext;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.eclipse.jetty.websocket.api.WebSocketPolicy;
  import org.eclipse.jetty.websocket.api.annotations.WebSocket;
  import org.eclipse.jetty.websocket.api.extensions.ExtensionFactory;
  
  /**
   * Basic WebSocketServletFactory for working with Jetty-based WebSocketServlets
   */
  public interface WebSocketServletFactory
  {
      public static class Loader
      {
          private static WebSocketServletFactory INSTANCE;
  
          public static WebSocketServletFactory create(WebSocketPolicy policy) throws ClassNotFoundException, InstantiationException, IllegalAccessException
          {
              return load().createFactory(policy);
          }
  
          public static WebSocketServletFactory load() throws ClassNotFoundException, InstantiationException, IllegalAccessException
          {
              if (INSTANCE != null)
              {
                  return INSTANCE;
              }
              WebSocketServletFactory baseFactory;
              Iterator<WebSocketServletFactory> factories = ServiceLoader.load(WebSocketServletFactory.class).iterator();
  
              if (factories.hasNext())
              {
                  baseFactory = factories.next();
              }
              else
              {
                  // Load the default class if ServiceLoader mechanism isn't valid in this environment. (such as OSGi)
                  ClassLoader loader = Thread.currentThread().getContextClassLoader();
                  @SuppressWarnings("unchecked")
                  Class<WebSocketServletFactory> wssf = (Class<WebSocketServletFactory>)loader
                          .loadClass("org.eclipse.jetty.websocket.server.WebSocketServerFactory");
                  baseFactory = wssf.newInstance();
              }
              
              INSTANCE = baseFactory;
              return INSTANCE;
          }
      }
  
      public boolean acceptWebSocket(HttpServletRequest request, HttpServletResponse response) throws IOException;
  
      public boolean acceptWebSocket(WebSocketCreator creator, HttpServletRequest request, HttpServletResponse response) throws IOException;
  
      public void cleanup();
  
      public WebSocketServletFactory createFactory(WebSocketPolicy policy);
  
      public abstract WebSocketCreator getCreator();
  
      public abstract ExtensionFactory getExtensionFactory();
  
      /**
       * Get the base policy in use for WebSockets.
       * <p>
       * Note: individual WebSocket implementations can override some of the values in here by using the {@link WebSocket &#064;WebSocket} annotation.
       * 
       * @return the base policy
       */
      public WebSocketPolicy getPolicy();
  
      public void init(ServletContext servletContext) throws Exception;
  
      public boolean isUpgradeRequest(HttpServletRequest request, HttpServletResponse response);
  
     /**
      * Register a websocket class pojo with the default {@link WebSocketCreator}.
      * <p>
      * Note: only required if using the default {@link WebSocketCreator} provided by this factory.
      * 
      * @param websocketPojo
      *            the class to instantiate for each incoming websocket upgrade request.
      */
     public void register(Class<?> websocketPojo);
 
     public abstract void setCreator(WebSocketCreator creator);
 }