package geniusweb.runserver.websocket;

import java.io.IOException;
import java.util.List;
import java.util.logging.Level;
import java.util.stream.Collectors;

import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

import com.fasterxml.jackson.databind.ObjectMapper;

import geniusweb.protocol.NegoProtocol;
import geniusweb.runserver.RunningNego;
import geniusweb.runserver.RunningNegotiationsRepo;
import tudelft.utilities.listener.Listener;
import tudelft.utilities.logging.ReportToLogger;
import tudelft.utilities.logging.Reporter;

/**
 * Returns a websocket that communicates the list of currently running
 * {@link NegoProtocol}s. Every time something changes, a new list of
 * {@link RunningNego}s is sent.
 */
@ServerEndpoint("/websocket/running")
public class RunningListSocket {

	private Listener<String> changeListener; // final, but only initialized in
												// startSession.
	private Session session; // a web session, not a negotiatino session
	private RunningNegotiationsRepo repo;
	private final static ObjectMapper jackson = new ObjectMapper();
	private final Reporter log;

	public RunningListSocket() {
		this(new ReportToLogger("runserver"));
	}

	public RunningListSocket(Reporter reporter) {
		this.log = reporter;
	}

	@OnOpen
	public void start(Session session) throws IOException {
		this.session = session;

		repo = getRepo();
		changeListener = new Listener<String>() {
			@Override
			public void notifyChange(String data) {
				sendUpdatedSessions();
			}
		};
		repo.addListener(changeListener);

		sendUpdatedSessions();
	}

	/**
	 * Send the currently running sessions to the client.
	 */
	private void sendUpdatedSessions() {
		List<String> list = repo.list().stream().map(session -> session.getID())
				.collect(Collectors.toList());
		try {
			System.out.println("new running negotiations:" + list);
			session.getBasicRemote().sendText(jackson.writeValueAsString(list));
		} catch (IOException e) {
			log.log(Level.SEVERE, "Internal problem converting json", e);
		}
	}

	@OnClose
	public void end() throws IOException {
		repo.removeListener(changeListener);
	}

	@OnError
	public void onError(Throwable t) throws Throwable {
		log.log(Level.SEVERE, "Internal problem converting json", t);
	}

	/**
	 * FactoryMethod for testing
	 * 
	 * @return RunningPartiesRepo
	 */
	protected RunningNegotiationsRepo getRepo() {
		return RunningNegotiationsRepo.instance();
	}

}