package ch.hevs.isi.field;

import com.serotonin.modbus4j.ModbusFactory;
import com.serotonin.modbus4j.ModbusMaster;
import com.serotonin.modbus4j.code.DataType;
import com.serotonin.modbus4j.exception.ErrorResponseException;
import com.serotonin.modbus4j.exception.ModbusTransportException;
import com.serotonin.modbus4j.ip.IpParameters;
import com.serotonin.modbus4j.ip.tcp.TcpMaster;
import com.serotonin.modbus4j.locator.BaseLocator;

public class ModbusAccessor {

    private static ModbusAccessor mySelf = null;
    private ModbusMaster master = null;

    /**
     * private constructor
     * */
    private ModbusAccessor(){

    }

    /**
     * static method to create a singleton pattern of the class
     * checks if an instance of the class is already made
     * if not, it creates an instance of the class ModbusAccessor
     * @return instance of ModbusAccessor
     */
    public static ModbusAccessor getMySelf(){
        if (mySelf == null){
            mySelf = new ModbusAccessor();
        }
        return mySelf;
    }

    public void connect(String ipAddress, int port){
        ModbusFactory MF = new ModbusFactory();
        IpParameters IpParams = new IpParameters();

        this.master = MF.createTcpMaster(IpParams, true);
        /**
         * TODO finish connect()
         */
    }

    /**
     * methods to write in the modbus registers
     */

    /**
     * method to write a boolean value on the modbus address
     * @param address the address of the modbus register
     * @param value the value to write in the register
     */
    public void writeBoolean (int address, boolean value){
        /**
         * TODO writeBoolean()
         */
    }

    /**
     * method to write a float value on the modbus address
     * @param address the address of the modbus register
     * @param value the value to write in the register
     */
    public void writeFloat (int address, float value){
        /**
         * TODO writeFloat()
         */
    }

    /**
     * methods to read from the modbus registers
     */

    /**
     * method to read a boolean value in the correct modbus register
     * get the coil status of the register.
     * @param register address of register
     * @return  boolean value of the desired register
     */
    public boolean readBoolean(int register) throws ModbusTransportException, ErrorResponseException {
        /**
         * first parameter = slaveID = always 1 because we only have one
         * second parameter = register address ==> it is named offset because it starts with 0 and goes to the desired address
         */
        boolean booleanValue = this.master.getValue(BaseLocator.coilStatus(1,register));
       return booleanValue;
    }

    /**
     * method to read a boolean value in the correct modbus register
     * get the value from the holding register
     * @param register address of the register
     * @return float value of the desired register
     */
    public float readFloat(int register){
        /**
         * first parameter = slaveID = always 1 because we only have one
         * second parameter = register address ==> it is named offset because it starts with 0 and goes to the desired address
         * thrid parameter = DataType of the value. The max value is 3 Byte Float, but the class DataType has only 2 or 4 byte
         */
       float floatValue = this.master.getValue(BaseLocator.holdingRegister(1,register, DataType.FOUR_BYTE_FLOAT);
        return floatValue;
    }
}