package com.example.carcontroller.SLAM;

import com.example.carcontroller.SlamScan;
import com.google.protobuf.InvalidProtocolBufferException;

import org.zeromq.SocketType;
import org.zeromq.ZContext;
import org.zeromq.ZMQ;

/**
 * Connects to Pi and retrieves updates of the SLAM map,
 * notifying listeners of changes to the map when they arrive.
 * Uses 0MQ for the transport.
 */
public class ZmqSlamUpdater extends SlamUpdater {

    private ZContext context;
    private String host;
    private String port;
    private boolean running = false;

    public ZmqSlamUpdater(String host, String port) {
        super();
        this.host = host;
        this.port = port;
        init();
    }

    @Override
    protected void init() {
        super.init();
        context = new ZContext();
    }


    @Override
    public void run() {
        // Should send a gRPC message to start listening...


        running = true;
        // Receive map from zmq and update appropriately.
        try (ZMQ.Socket socket = context.createSocket(SocketType.PAIR)) {
            socket.connect("tcp://" + host + ":" + port);
            socket.send("Hi");
            while (running) {
                byte[] map = socket.recv();
                fireMapChanged(SlamScan.parseFrom(map));
            }
        } catch (InvalidProtocolBufferException e) {
            System.out.println("Invalid map found");
            running = false;
        }
    }


    public void stop() {
        running = false;
    }
}