/*
    * Copyright 2016 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:
    *
    *   https://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.http2;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.ByteBufUtil;
  import io.netty.buffer.Unpooled;
  import io.netty.util.internal.StringUtil;
  import io.netty.util.internal.UnstableApi;
  
  import static io.netty.handler.codec.http2.Http2CodecUtil.verifyPadding;
  import static io.netty.util.internal.ObjectUtil.checkNotNull;
  
  /**
   * The default {@link Http2DataFrame} implementation.
   */
  @UnstableApi
  public final class DefaultHttp2DataFrame extends AbstractHttp2StreamFrame implements Http2DataFrame {
      private final ByteBuf content;
      private final boolean endStream;
      private final int padding;
      private final int initialFlowControlledBytes;
  
      /**
       * Equivalent to {@code new DefaultHttp2DataFrame(content, false)}.
       *
       * @param content non-{@code null} payload
       */
      public DefaultHttp2DataFrame(ByteBuf content) {
          this(content, false);
      }
  
      /**
       * Equivalent to {@code new DefaultHttp2DataFrame(Unpooled.EMPTY_BUFFER, endStream)}.
       *
       * @param endStream whether this data should terminate the stream
       */
      public DefaultHttp2DataFrame(boolean endStream) {
          this(Unpooled.EMPTY_BUFFER, endStream);
      }
  
      /**
       * Equivalent to {@code new DefaultHttp2DataFrame(content, endStream, 0)}.
       *
       * @param content non-{@code null} payload
       * @param endStream whether this data should terminate the stream
       */
      public DefaultHttp2DataFrame(ByteBuf content, boolean endStream) {
          this(content, endStream, 0);
      }
  
      /**
       * Construct a new data message.
       *
       * @param content non-{@code null} payload
       * @param endStream whether this data should terminate the stream
       * @param padding additional bytes that should be added to obscure the true content size. Must be between 0 and
       *                256 (inclusive).
       */
      public DefaultHttp2DataFrame(ByteBuf content, boolean endStream, int padding) {
          this.content = checkNotNull(content, "content");
          this.endStream = endStream;
          verifyPadding(padding);
          this.padding = padding;
          if (content().readableBytes() + (long) padding > Integer.MAX_VALUE) {
              throw new IllegalArgumentException("content + padding must be <= Integer.MAX_VALUE");
          }
          initialFlowControlledBytes = content().readableBytes() + padding;
      }
  
      @Override
      public DefaultHttp2DataFrame stream(Http2FrameStream stream) {
          super.stream(stream);
          return this;
      }
  
      @Override
      public String name() {
          return "DATA";
      }
  
      @Override
      public boolean isEndStream() {
          return endStream;
      }
  
     @Override
     public int padding() {
         return padding;
     }
 
     @Override
     public ByteBuf content() {
         return ByteBufUtil.ensureAccessible(content);
     }
 
     @Override
     public int initialFlowControlledBytes() {
         return initialFlowControlledBytes;
     }
 
     @Override
     public DefaultHttp2DataFrame copy() {
         return replace(content().copy());
     }
 
     @Override
     public DefaultHttp2DataFrame duplicate() {
         return replace(content().duplicate());
     }
 
     @Override
     public DefaultHttp2DataFrame retainedDuplicate() {
         return replace(content().retainedDuplicate());
     }
 
     @Override
     public DefaultHttp2DataFrame replace(ByteBuf content) {
         return new DefaultHttp2DataFrame(content, endStream, padding);
     }
 
     @Override
     public int refCnt() {
         return content.refCnt();
     }
 
     @Override
     public boolean release() {
         return content.release();
     }
 
     @Override
     public boolean release(int decrement) {
         return content.release(decrement);
     }
 
     @Override
     public DefaultHttp2DataFrame retain() {
         content.retain();
         return this;
     }
 
     @Override
     public DefaultHttp2DataFrame retain(int increment) {
         content.retain(increment);
         return this;
     }
 
     @Override
     public String toString() {
         return StringUtil.simpleClassName(this) + "(stream=" + stream() + ", content=" + content
                + ", endStream=" + endStream + ", padding=" + padding + ')';
     }
 
     @Override
     public DefaultHttp2DataFrame touch() {
         content.touch();
         return this;
     }
 
     @Override
     public DefaultHttp2DataFrame touch(Object hint) {
         content.touch(hint);
         return this;
     }
 
     @Override
     public boolean equals(Object o) {
         if (!(o instanceof DefaultHttp2DataFrame)) {
             return false;
         }
         DefaultHttp2DataFrame other = (DefaultHttp2DataFrame) o;
         return super.equals(other) && content.equals(other.content())
             && endStream == other.endStream && padding == other.padding;
     }
 
     @Override
     public int hashCode() {
         int hash = super.hashCode();
         hash = hash * 31 + content.hashCode();
         hash = hash * 31 + (endStream ? 0 : 1);
         hash = hash * 31 + padding;
         return hash;
     }
 }