/*
    * Copyright 2013 The Netty Project
    *
    * The Netty Project 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 io.netty.handler.codec.http.websocketx;
  
  
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.handler.codec.MessageToMessageDecoder;
  
  import java.util.List;
  
  abstract class WebSocketProtocolHandler extends MessageToMessageDecoder<WebSocketFrame> {
      @Override
      protected void decode(ChannelHandlerContext ctx, WebSocketFrame frame, List<Object> out) throws Exception {
          if (frame instanceof PingWebSocketFrame) {
              frame.content().retain();
              ctx.channel().writeAndFlush(new PongWebSocketFrame(frame.content()));
              return;
          }
          if (frame instanceof PongWebSocketFrame) {
              // Pong frames need to get ignored
              return;
          }
  
          out.add(frame.retain());
      }
  
      @Override
      public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
          ctx.fireExceptionCaught(cause);
          ctx.close();
      }
  }