/*
    * 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.sctp;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.sctp.SctpMessage;
  import io.netty.handler.codec.CodecException;
  import io.netty.handler.codec.MessageToMessageDecoder;
  
  import java.util.List;
  
  /**
   * A ChannelHandler which receives {@link SctpMessage}s which belong to a application protocol form a specific
   * SCTP Stream  and decode it as {@link ByteBuf}.
   */
  public class SctpInboundByteStreamHandler extends MessageToMessageDecoder<SctpMessage> {
      private final int protocolIdentifier;
      private final int streamIdentifier;
  
      /**
       * @param streamIdentifier   accepted stream number, this should be >=0 or <= max stream number of the association.
       * @param protocolIdentifier supported application protocol.
       */
      public SctpInboundByteStreamHandler(int protocolIdentifier, int streamIdentifier) {
          this.protocolIdentifier = protocolIdentifier;
          this.streamIdentifier = streamIdentifier;
      }
  
      @Override
      public final boolean acceptInboundMessage(Object msg) throws Exception {
          if (super.acceptInboundMessage(msg)) {
              return acceptInboundMessage((SctpMessage) msg);
          }
          return false;
      }
  
      protected boolean acceptInboundMessage(SctpMessage msg) {
          return msg.protocolIdentifier() == protocolIdentifier && msg.streamIdentifier() == streamIdentifier;
      }
  
      @Override
      protected void decode(ChannelHandlerContext ctx, SctpMessage msg, List<Object> out) throws Exception {
          if (!msg.isComplete()) {
              throw new CodecException(String.format("Received SctpMessage is not complete, please add %s in the " +
                      "pipeline before this handler", SctpMessageCompletionHandler.class.getSimpleName()));
          }
          out.add(msg.content().retain());
      }
  }