from pymodbus.client import ModbusTcpClient
from pymodbus.exceptions import ModbusIOException
from pymodbus.register_read_message import ReadHoldingRegistersResponse, ReadInputRegistersResponse
from pymodbus.payload import BinaryPayloadBuilder, BinaryPayloadDecoder
from pymodbus.constants import Endian

from loguru import logger
import sys
import logging
from time import sleep


class LocalException(Exception):
  def __init__(self, msg='', cause=None):
    super().__init__(self)
    self.msg = msg
    self.cause = cause
  
  def __str__(self):
    return f"LocalException: Msg:{self.msg}, Cause:{self.cause}"

def readInputRegister(client, addr):
  client.connect()
  try:
    res = client.read_input_registers(addr, 2, slave=2)
    if (isinstance(res, ReadInputRegistersResponse)):
      v = BinaryPayloadDecoder.fromRegisters(res.registers, byteorder=Endian.Big, wordorder=Endian.Big).decode_32bit_float()
      return v
    elif (isinstance(res, ModbusIOException)):
      msg = f"Error: {type(res)}, Content: {res}"
      logger.warning(msg)
      raise LocalException(msg=msg, cause=res)
    else:
      msg = f"Unknown type: {type(res)}, Content: {res}"
      logger.warning(msg)
      raise LocalException(msg=msg)
  finally:
    client.close()

def writeCoil(client, addr, value):
  client.connect()
  try:
    res = client.write_coil(addr, value, slave=1)
    logger.debug(f"write coil result {res}")
    return value
  finally:
    client.close()


l = logging.getLogger()
for h in l.handlers:
  l.removeHandler(h)

client = ModbusTcpClient("172.16.2.42")
registers = [
  { "addr":0x0046, "name":"Frequency", "unit":"Hz" },
  { "addr":0x0048, "name":"Import active energy", "unit":"kWh" },
  { "addr":0x004a, "name":"Export active energy", "unit":"kWh" },
  { "addr":0x004c, "name":"Import reactive energy", "unit":"kvarh" },
  { "addr":0x004e, "name":"Export reactive energy", "unit":"kvarh" },
  { "addr":0x000c, "name":"Active power", "unit":"W" },
  { "addr":0x0058, "name":"Positive power", "unit":"W" },
  { "addr":0x005c, "name":"Reverse power", "unit":"W" },
  { "addr":0x0000, "name":"Voltage", "unit":"V" },
  { "addr":0x0006, "name":"Current", "unit":"A" }
]


cnt = 0
coilState = True
while True:
  try:
    for reg in registers:
      v = readInputRegister(client, reg['addr'])
      logger.info(f"{reg['name']}: {v} {reg['unit']}")

    cnt += 1
    if ((cnt % 2) == 0):
      coilState = not coilState
      logger.info(f"Write {coilState} to coil")
      writeCoil(client, 0, coilState)



    sleep(5)
  except Exception as e:
    logger.error(f"Caught exception: {str(e)}")