/*
 * Copyright 2009 Thomas Bocek
 * 
 * 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 net.tomp2p.message;

import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.ChannelDownstreamHandler;
import org.jboss.netty.channel.ChannelEvent;
import org.jboss.netty.channel.ChannelHandler.Sharable;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.MessageEvent;

import static org.jboss.netty.channel.Channels.write;

@Sharable
public class TomP2PEncoderUDP implements ChannelDownstreamHandler
{
	@Override
	public void handleDownstream(ChannelHandlerContext ctx, ChannelEvent e) throws Exception
	{
		if (!(e instanceof MessageEvent))
		{
			ctx.sendDownstream(e);
			return;
		}
		MessageEvent evt = (MessageEvent) e;
		Object msg = evt.getMessage();
		if (!(msg instanceof Message))
		{
			ctx.sendDownstream(evt);
			return;
		}
		Message message = (Message) msg;
		final ChannelBuffer headerBuffer = ChannelBuffers.buffer(MessageCodec.HEADER_SIZE);
		MessageCodec.encodeHeader(headerBuffer, message);
		if (message.hasContent())
		{
			
			ProtocolChunkedInput input = new ProtocolChunkedInput(ctx, message.getPrivateKey());
			input.copyToCurrent(headerBuffer);
			MessageCodec.encodePayload(message, input);
			//for UDP we need to flatten this
			int size = input.size();
			ChannelBuffer[] tmp = new ChannelBuffer[size];
			for (int i = 0; i < size; i++)
				tmp[i] = (ChannelBuffer) input.nextChunk();
			write(ctx, e.getFuture(), ChannelBuffers.wrappedBuffer(tmp), evt.getRemoteAddress());
		}
		else
		{
			write(ctx, e.getFuture(), headerBuffer, evt.getRemoteAddress());
		}
	}
}