uraxisdaemon/src/main/java/at/acdp/urweb/rtde/RTDEClient.java

package at.acdp.urweb.rtde;

import org.slf4j.LoggerFactory;

import java.io.*;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.List;

import static at.acdp.urweb.rtde.CommandType.RTDE_REQUEST_PROTOCOL_VERSION;

public class RTDEClient implements Runnable {
    private final static org.slf4j.Logger logger = LoggerFactory.getLogger(RTDEClient.class);

    private final String ip;
    private final int port;
    private volatile boolean _running=true;
    private DataOutputStream dos;
    private DataInputStream dis;
    public static int RTDE_PROTOCOL_VERSION=2;


    public RTDEClient(String ip, int port) {
        this.ip=ip;
        this.port=port;
    }

    public void start() throws IOException {
        try (Socket rt = new Socket(ip, port);) {
            rt.setSoTimeout(0);
            rt.setReuseAddress(true);
            rt.setTcpNoDelay(true);
            if (rt.isConnected()) {
                System.out.println("Connected to UR Realtime Client");
            }
            dos = new DataOutputStream(rt.getOutputStream());
            dis = new DataInputStream(rt.getInputStream());

            negotiate_protocol_version();
            //Thread readThread = new Thread(this);
            //readThread.start();
            // send_output_setup(List.of(OutParams.timestamp), List.of(), 125);
        }
    }

    // Internal method that actually reads the data
    private void readSocket() throws IOException {
        while(true) {
            int length = dis.readInt();
            double[] rtm = new double[length];
            rtm[0] = length;
            // Calculate how much data is available from the length
            int data_available = (length - 4) / 8;
            for(int i=0; i<data_available; i++){
                rtm[i] = dis.readDouble();
            }
        }

    }

    private interface RtdeData<T> {
        public CommandType getType();
        public T read(DataInputStream di) throws IOException;
        public T send(DataOutputStream dos) throws IOException;


    }
    private class RtdeRequestProtocolVersion implements RtdeData{
        public  int major, minor, bugfix, build;
        int size=5;

        @Override
        public CommandType getType() {
            return RTDE_REQUEST_PROTOCOL_VERSION;
        }

        @Override
        public RtdeRequestProtocolVersion read(DataInputStream d) throws IOException {
             major = d.readInt();
             minor = d.readInt();
             bugfix = d.readInt();
             build = d.readInt();
             return this;
        }

        @Override
        public RtdeRequestProtocolVersion send(DataOutputStream dos) throws IOException {
            dos.writeByte(5);
            dos.writeShort(getType().getVal());
            dos.writeShort(RTDE_PROTOCOL_VERSION);
            dos.flush();
            return this;
        }
    }


    private void receive(RtdeData cmd) throws IOException {
        logger.info(cmd.getType().toString());
        cmd.read(dis);
    }

    @Override
    public void run() {
        try {
            negotiate_protocol_version();
        } catch (IOException e) {
            e.printStackTrace();
        }

        while(_running) {
            try {
                readSocket();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public void send_input_setup(List<String> variables, List<String> types) throws IOException {
        var cmd = CommandType.RTDE_CONTROL_PACKAGE_SETUP_INPUTS;
        var payload = String.join(",", variables);
        var rpv = new RtdeRequestProtocolVersion();
    }

    private void sendAndReceive(RtdeData cmd) throws IOException {
        cmd.send(dos);
        cmd.read(dis);
    }


    public void send_output_setup(List<String> variables, List<String> types, int frequency) throws IOException {
        var payload = String.join(",", variables);
        byte[] p= payload.getBytes();
        ByteBuffer bytes = ByteBuffer.allocate(8+p.length);
        bytes.putDouble(frequency);
        bytes.put(p);

        // sendAndReceive(rpv, bytes.array());
    }


    public void negotiate_protocol_version() throws IOException {
        var rpv = new RtdeRequestProtocolVersion();
        sendAndReceive(rpv);
    }
}