/*
    * 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.myfaces.push;
  
  import org.apache.myfaces.push.cdi.WebsocketApplicationSessionHolder;
  import java.io.IOException;
  import java.io.Serializable;
  import javax.enterprise.inject.spi.BeanManager;
  import javax.enterprise.inject.spi.CDI;
  import javax.enterprise.util.AnnotationLiteral;
  import javax.faces.event.WebsocketEvent;
  import javax.faces.event.WebsocketEvent.Closed;
  import javax.faces.event.WebsocketEvent.Opened;
  import javax.websocket.CloseReason;
  import javax.websocket.CloseReason.CloseCodes;
  import javax.websocket.Endpoint;
  import javax.websocket.EndpointConfig;
  import javax.websocket.Session;
  
  /**
   *
   */
  public class EndpointImpl extends Endpoint
  {
  
      public static final String JAVAX_FACES_PUSH_PATH = "/javax.faces.push/{channel}";
  
      public static final String PUSH_CHANNEL_PARAMETER = "channel";
      
      private static final AnnotationLiteral<Opened> OPENED = 
              new AnnotationLiteral<Opened>() 
              {
                  private static final long serialVersionUID = 2789324L;
              };
      private static final AnnotationLiteral<Closed> CLOSED = 
              new AnnotationLiteral<Closed>() 
              {
                  private static final long serialVersionUID = 38450203L;
              };
  
      @Override
      public void onOpen(Session session, EndpointConfig config)
      {
          // Get the channel and the channel id
          String channel = session.getPathParameters().get(PUSH_CHANNEL_PARAMETER);
          String channelToken = session.getQueryString();
  
          // Locate holder
          // Note in this point there is no session scope because there is no HttpSession available,
          // but on the handshake there is. So, everything below should use CDI application scoped
          // beans only.
  
          if (Boolean.TRUE.equals(config.getUserProperties().get(WebsocketConfigurator.WEBSOCKET_VALID)) &&
                  WebsocketApplicationSessionHolder.addOrUpdateSession(channelToken, session))
          {
              session.setMaxIdleTimeout((Long) config.getUserProperties().getOrDefault(
                      WebsocketConfigurator.MAX_IDLE_TIMEOUT, 300000L));
  
              Serializable user = (Serializable) session.getUserProperties().get(WebsocketConfigurator.WEBSOCKET_USER);
  
              BeanManager beanManager = CDI.current().getBeanManager();
              beanManager.fireEvent(new WebsocketEvent(channel, user, null), OPENED);
              
              session.getUserProperties().put(
                      WebsocketSessionClusterSerializedRestore.WEBSOCKET_SESSION_SERIALIZED_RESTORE, 
                      new WebsocketSessionClusterSerializedRestore(channelToken));
          }
          else
          {
              try
              {
                  session.close(new CloseReason(CloseCodes.UNEXPECTED_CONDITION,
                          "Websocket connection not registered in current session"));
              }
              catch (IOException ex)
              {
                  onError(session, ex);
              }
          }
      }
  
      @Override
      public void onClose(Session session, CloseReason closeReason)
     {
         // Get the channel and the channel id
         String channel = session.getPathParameters().get(PUSH_CHANNEL_PARAMETER);
         String channelToken = session.getQueryString();
 
         Serializable user = (Serializable) session.getUserProperties().get(WebsocketConfigurator.WEBSOCKET_USER);
 
         // In this point in some cases (close reason 1006) CDI does not work and you cannot lookup application
         // scope beans, because the context could not be properly initialized. In that case we should try to
         // propagate the event but if an error happens, just ensure the Session is properly disposed.
         try
         {
             BeanManager beanManager = CDI.current().getBeanManager();
             beanManager.fireEvent(
                     new WebsocketEvent(channel, user, closeReason.getCloseCode()),  CLOSED);
         }
         catch(Exception e)
         {
             //No op because it is expected something could go wrong.
         }
         finally
         {
             WebsocketApplicationSessionHolder.removeSession(channelToken);
         }
     }
 
     @Override
     public void onError(Session session, Throwable ex)
     {
         if (session.isOpen())
         {
             session.getUserProperties().put(Throwable.class.getName(), ex);
         }
     }
 }