/*
    * Copyright (c) 2012 the original author or authors.
    *
    * 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.eclipse.jetty.spdy.generator;
  
  import java.nio.ByteBuffer;
  
  import org.eclipse.jetty.spdy.ByteBufferPool;
  import org.eclipse.jetty.spdy.api.SPDY;
  import org.eclipse.jetty.spdy.frames.ControlFrame;
  import org.eclipse.jetty.spdy.frames.GoAwayFrame;
  
  public class GoAwayGenerator extends ControlFrameGenerator
  {
      public GoAwayGenerator(ByteBufferPool bufferPool)
      {
          super(bufferPool);
      }
  
      @Override
      public ByteBuffer generate(ControlFrame frame)
      {
          GoAwayFrame goAway = (GoAwayFrame)frame;
  
          int frameBodyLength = 8;
          int totalLength = ControlFrame.HEADER_LENGTH + frameBodyLength;
          ByteBuffer buffer = getByteBufferPool().acquire(totalLength, true);
          generateControlFrameHeader(goAway, frameBodyLength, buffer);
  
          buffer.putInt(goAway.getLastStreamId() & 0x7F_FF_FF_FF);
          writeStatusCode(goAway, buffer);
  
          buffer.flip();
          return buffer;
      }
  
      private void writeStatusCode(GoAwayFrame goAway, ByteBuffer buffer)
      {
          switch (goAway.getVersion())
          {
              case SPDY.V2:
                  break;
              case SPDY.V3:
                  buffer.putInt(goAway.getStatusCode());
                  break;
              default:
                  throw new IllegalStateException();
          }
      }
  }