package geniusweb.profilesserver.websocket;

import java.io.IOException;

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

import com.fasterxml.jackson.databind.ObjectMapper;

import geniusweb.profile.Profile;
import geniusweb.profilesserver.ProfilesFactory;
import geniusweb.profilesserver.events.ChangeEvent;
import tudelft.utilities.listener.Listener;

/**
 * Returns a websocket that communicates the list of currently available domains
 * and profiles. Every time something changes, a new list of domains and
 * profiles is sent. For each new websocket the server will create one of this
 * but they all share one {@link ProfilesFactory}.
 */
@ServerEndpoint("/websocket/get/{domain}/{profile}")
public class GetProfileSocket {
	private final static ObjectMapper jackson = new ObjectMapper();
	private Profile prof = null; // the latest that we sent to client.

	// should all be final, except that we can only set them when start is
	// called...
	private String profilename;
	private Listener<ChangeEvent> changeListener;
	private Session session;

	@OnOpen
	public void start(Session session, @PathParam("domain") final String domain,
			@PathParam("profile") final String profile) throws IOException {
		this.session = session;
		this.profilename = domain + "/" + profile;

		changeListener = new Listener<ChangeEvent>() {
			@Override
			public void notifyChange(ChangeEvent data) {
				sendupdatedProfile();
			}
		};
		sendupdatedProfile();
		Profiles.factory.addListener(changeListener);
	}

	private void sendupdatedProfile() {
		Profile newprof = Profiles.factory.getProfile(profilename);
		// notice, may be null if profile does not exist/was removed.
		if (newprof == null ? prof != null : !newprof.equals(prof)) {
			prof = newprof;
			try {
				session.getBasicRemote()
						.sendText(jackson.writeValueAsString(prof));
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	}

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

	@OnError
	public void onError(Throwable t) throws Throwable {
		t.printStackTrace();
	}

}