/*
    * Copyright 2012 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.buffer.ByteBuf;
  import io.netty.buffer.Unpooled;
  import io.netty.util.CharsetUtil;
  import io.netty.util.internal.EmptyArrays;
  
  /**
   * Web Socket Frame for closing the connection
   */
  public class CloseWebSocketFrame extends WebSocketFrame {
  
      /**
       * Creates a new empty close frame.
       */
      public CloseWebSocketFrame() {
          super(Unpooled.buffer(0));
      }
  
      /**
       * Creates a new empty close frame with closing getStatus code and reason text
       *
       * @param statusCode
       *            Integer status code as per <a href="http://tools.ietf.org/html/rfc6455#section-7.4">RFC 6455</a>. For
       *            example, <tt>1000</tt> indicates normal closure.
       * @param reasonText
       *            Reason text. Set to null if no text.
       */
      public CloseWebSocketFrame(int statusCode, String reasonText) {
          this(true, 0, statusCode, reasonText);
      }
  
      /**
       * Creates a new close frame with no losing getStatus code and no reason text
       *
       * @param finalFragment
       *            flag indicating if this frame is the final fragment
       * @param rsv
       *            reserved bits used for protocol extensions
       */
      public CloseWebSocketFrame(boolean finalFragment, int rsv) {
          this(finalFragment, rsv, Unpooled.buffer(0));
      }
  
      /**
       * Creates a new close frame with closing status code and reason text
       *
       * @param finalFragment
       *            flag indicating if this frame is the final fragment
       * @param rsv
       *            reserved bits used for protocol extensions
       * @param statusCode
       *            Integer status code as per <a href="http://tools.ietf.org/html/rfc6455#section-7.4">RFC 6455</a>. For
       *            example, <tt>1000</tt> indicates normal closure.
       * @param reasonText
       *            Reason text. Set to null if no text.
       */
      public CloseWebSocketFrame(boolean finalFragment, int rsv, int statusCode, String reasonText) {
          super(finalFragment, rsv, newBinaryData(statusCode, reasonText));
      }
  
      private static ByteBuf newBinaryData(int statusCode, String reasonText) {
          byte[] reasonBytes = EmptyArrays.EMPTY_BYTES;
          if (reasonText != null) {
              reasonBytes = reasonText.getBytes(CharsetUtil.UTF_8);
          }
  
          ByteBuf binaryData = Unpooled.buffer(2 + reasonBytes.length);
          binaryData.writeShort(statusCode);
          if (reasonBytes.length > 0) {
              binaryData.writeBytes(reasonBytes);
          }
  
          binaryData.readerIndex(0);
          return binaryData;
      }
  
      /**
       * Creates a new close frame
       *
       * @param finalFragment
       *            flag indicating if this frame is the final fragment
       * @param rsv
       *            reserved bits used for protocol extensions
      * @param binaryData
      *            the content of the frame. Must be 2 byte integer followed by optional UTF-8 encoded string.
      */
     public CloseWebSocketFrame(boolean finalFragment, int rsv, ByteBuf binaryData) {
         super(finalFragment, rsv, binaryData);
     }
 
     /**
      * Returns the closing status code as per <a href="http://tools.ietf.org/html/rfc6455#section-7.4">RFC 6455</a>. If
      * a getStatus code is set, -1 is returned.
      */
     public int statusCode() {
         ByteBuf binaryData = content();
         if (binaryData == null || binaryData.capacity() == 0) {
             return -1;
         }
 
         binaryData.readerIndex(0);
         int statusCode = binaryData.readShort();
         binaryData.readerIndex(0);
 
         return statusCode;
     }
 
     /**
      * Returns the reason text as per <a href="http://tools.ietf.org/html/rfc6455#section-7.4">RFC 6455</a> If a reason
      * text is not supplied, an empty string is returned.
      */
     public String reasonText() {
         ByteBuf binaryData = content();
         if (binaryData == null || binaryData.capacity() <= 2) {
             return "";
         }
 
         binaryData.readerIndex(2);
         String reasonText = binaryData.toString(CharsetUtil.UTF_8);
         binaryData.readerIndex(0);
 
         return reasonText;
     }
 
     @Override
     public CloseWebSocketFrame copy() {
         return new CloseWebSocketFrame(isFinalFragment(), rsv(), content().copy());
     }
 
     @Override
     public CloseWebSocketFrame duplicate() {
         return new CloseWebSocketFrame(isFinalFragment(), rsv(), content().duplicate());
     }
 
     @Override
     public CloseWebSocketFrame retain() {
         super.retain();
         return this;
     }
 
     @Override
     public CloseWebSocketFrame retain(int increment) {
         super.retain(increment);
         return this;
     }
 }