package suikwasha.distributedalgorithm.link;

import java.util.concurrent.LinkedBlockingQueue;

import suikwasha.distributedalgorithm.framework.Link;
import suikwasha.distributedalgorithm.framework.LinkBuilder;
import suikwasha.distributedalgorithm.framework.Message;
import suikwasha.distributedalgorithm.framework.Port;

public class ReliableLinkBuilder implements LinkBuilder
{
	public Link build()
	{
		return new LinkImpl();
	}
	
	private static class LinkImpl implements Link
	{
		private final Port port1,port2;
		
		public LinkImpl()
		{
			LinkedBlockingQueue<Message> queue1 = new LinkedBlockingQueue<Message>();
			LinkedBlockingQueue<Message> queue2 = new LinkedBlockingQueue<Message>();
			
			port1 = new PortImpl(queue1,queue2);
			port2 = new PortImpl(queue2,queue1);
		}

		public Port getPort1()
		{
			return port1;
		}

		public Port getPort2()
		{
			return port2;
		}
	}
	
	private static class PortImpl implements Port
	{
		private final LinkedBlockingQueue<Message> in;
		private final LinkedBlockingQueue<Message> out;
		
		public PortImpl(LinkedBlockingQueue<Message> _in,LinkedBlockingQueue<Message> _out)
		{
			in = _in;
			out = _out;
		}

		public void send(Message _mes)
		{
			out.add(_mes);
		}

		public Message blockingReceive() throws InterruptedException
		{
			return in.take();
		}

		public Message tryReceive()
		{
			return in.poll();
		}

		public boolean isReady()
		{
			return !in.isEmpty();
		}
	}
}