package at.acdp.urweb.fhpp;

import java.nio.charset.Charset;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import com.digitalpetri.modbus.codec.Modbus;
import com.digitalpetri.modbus.master.ModbusTcpMaster;
import com.digitalpetri.modbus.master.ModbusTcpMasterConfig;
import com.digitalpetri.modbus.requests.ReadHoldingRegistersRequest;
import com.digitalpetri.modbus.requests.WriteMultipleRegistersRequest;
import com.digitalpetri.modbus.requests.WriteSingleRegisterRequest;
import com.digitalpetri.modbus.responses.ReadHoldingRegistersResponse;
import io.netty.buffer.ByteBuf;
import io.netty.util.ReferenceCountUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class FHMaster {

    public static void main(String[] args) {
        new FHMaster(100, 100).start();
    }

    private final Logger logger = LoggerFactory.getLogger(getClass());

    private final ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();

    private final List<ModbusTcpMaster> masters = new CopyOnWriteArrayList<>();
    private volatile boolean started = false;

    private final int nMasters;
    private final int nRequests;

    public FHMaster(int nMasters, int nRequests) {
        this.nMasters = nMasters;
        this.nRequests = nRequests;
    }

    public void start() {
        started = true;

        ModbusTcpMasterConfig config = new ModbusTcpMasterConfig.Builder("10.0.31.14")
                .setPort(502)
                .build();

        new Thread(() -> {
            while (started) {
                try {
                    Thread.sleep(5000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

                double mean = 0.0;
                double oneMinute = 0.0;

                for (ModbusTcpMaster master : masters) {
                    mean += master.getResponseTimer().getMeanRate();
                    oneMinute += master.getResponseTimer().getOneMinuteRate();
                }

                logger.info("Mean rate={}, 1m rate={}", mean, oneMinute);
            }
        }).start();

        ModbusTcpMaster master = new ModbusTcpMaster(config);
        master.connect();
        sendAndReceive(master);

    }

    private void sendAndReceive(ModbusTcpMaster master) {
        if (!started) return;

        CompletableFuture<ReadHoldingRegistersResponse> future =
        master.sendRequest(new ReadHoldingRegistersRequest(0,4), 0);
        //master.sendRequest(new WriteMultipleRegistersRequest(0,4, new byte[]{0x01,0,0,0,0,0,0,0}), 0);

        //master.sendRequest(new ReadWriteMultipleRegisters(0, 4), 0);


        future.whenCompleteAsync((response, ex) -> {
            if (response != null) {
                ReferenceCountUtil.release(response);
                try {


                    var reg = response.getRegisters();
                    byte[] bytes = new byte[reg.readableBytes()];
                    System.out.println(String.format("%02X", bytes));
                }
                catch (Exception e) {
                    e.printStackTrace();
                }
            }
                else {
                logger.error("Completed exceptionally, message={}", ex.getMessage(), ex);
            }
            scheduler.schedule(() -> sendAndReceive(master), 1, TimeUnit.SECONDS);
        }, Modbus.sharedExecutor());
    }

    public void stop() {
        started = false;
        masters.forEach(ModbusTcpMaster::disconnect);
        masters.clear();
    }

}