package com.tyluur.network.decoders;

import java.util.NoSuchElementException;

import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.frame.FrameDecoder;

import com.tyluur.network.packet.OutgoingPacket;
import com.tyluur.utility.Constants;

/**
 * @author Tykuur
 */

public class ClientDecoder extends FrameDecoder {

	/**
	 * The opcode sent by the client to signal the file request start.
	 */
	private static final int FILE_REQUEST = 15,

	/**
	 * The opcode sent to the server to initiate login.
	 */
	LOGIN_REQUEST = 14;

	@Override
	protected Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) throws Exception {
		try {
			ctx.getPipeline().remove(this);
		} catch (NoSuchElementException e) { }
		int opcode = buffer.readByte() & 0xFF;
		OutgoingPacket response = new OutgoingPacket(null, opcode);
		switch(opcode) {
		case FILE_REQUEST:
			int revision = buffer.readInt();
			if (revision != Constants.REVISION) {
				response.put(6);
				channel.close();
			} else {
				response.put(6);
				OutgoingPacket packet = new OutgoingPacket(null, 6).put(3);
				packet.get();
				if (4 <= buffer.readableBytes()) {
					buffer.skipBytes(4);
					for (final int key : Constants.UPDATE_KEYS) {
						response.put((byte) key);
					}
					return true;
				}
			}
			break;
		case LOGIN_REQUEST:
			break;
		}
		return null;
	}


}