import drcl.comp.Port;
import drcl.inet.InetPacket;

/**
 * Example protocol class - echoer2.
 */
public class echoer2 extends drcl.inet.Protocol
{
	final static int REQ=1, RPL=2, tos=0;

	public echoer2()
	{ super(); }

	public echoer2(String id_)
	{ super(id_); }

	void sendmsg(int type_, double tm_, long dst_)
	{
		echopkt pkt_ = new echopkt(type_, tm_);
		
		forward(pkt_, 10/*size*/, drcl.net.Address.NULL_ADDR/*src*/, dst_,
				false/*routerAlert*/, 255/*TTL*/, tos);
	}

	public void send_echo_request(long dst_)
	{
		debug("Sending an Echo packet to node" + dst_);
		sendmsg(REQ, getTime(), dst_);
	}

	protected void dataArriveAtDownPort(Object data_, Port downPort_)
	{
		InetPacket ipkt_ = (InetPacket)data_;
		echopkt pkt_ = (echopkt)ipkt_.getBody();
		long src_ = ipkt_.getSource();
		if (pkt_.type==RPL)
		{
			double rtt = getTime() - pkt_.time;
			debug("Getting a reply, round-trip time is: " + rtt);
		}
		else {
			debug("Getting a request, sending time is: " + pkt_.time);
			sendmsg(RPL, pkt_.time, src_);
		}
	}
}