import sys
import traceback

import serial
from pymodbus.constants import Endian
# from pymodbus.exceptions import ModbusIOException
from pymodbus.payload import BinaryPayloadBuilder, BinaryPayloadDecoder
from PyQt5.QtCore import QMutex

if "--sim-modbus" not in sys.argv:
    from pymodbus.client.sync import ModbusSerialClient as ModbusClient
else:
    from components.dummies.pymodbus import ModbusClient

from .component import Component


class ModbusComponent(Component):
    def __init__(self, config=None, name=None, period=1, lazy=True, paused=False, threaded=True, registers=None):
        super().__init__(config=config, name=name, period=period, lazy=lazy, paused=paused, threaded=threaded)
        self.registers = registers if registers is not None else {}
        self.lock = QMutex()

    def config_changed(self):
        self.address = self.config[self.name]["address"]
        self.baudrate = int(self.config[self.name]["baudrate"])
        self.stopbits = getattr(serial, self.config[self.name].get("stopbits", "stopbits_one").upper())
        self.parity = getattr(serial, self.config[self.name].get("parity", "parity_none").upper())
        self.bytesize = getattr(serial, self.config[self.name].get("bytesize", "eightbits").upper())
        self.byteorder = getattr(Endian, self.config[self.name].get("byteorder", "Big").title())
        self.wordorder = getattr(Endian, self.config[self.name].get("wordorder", "Big").title())
        self.timeout = int(self.config[self.name].get("timeout", 1))
        self.lock.lock()
        self.client = ModbusClient(
            method="rtu",
            port=self.address,
            stopbits=self.stopbits,
            bytesize=self.bytesize,
            parity=self.parity,
            baudrate=self.baudrate,
            timeout=self.timeout,
            strict=False
        )
        if not self.client.connect():
            raise ConnectionError("device not reachable (could not connect): {} ({})".format(self.name, self.port))
        if not self.client.is_socket_open():
            raise ConnectionError("device not reachable (socket not open): {} ({})".format(self.name, self.port))
        self.lock.unlock()

    def _read(self, register, count=1):
        self.lock.lock()
        read = self.client.read_holding_registers(register, count=count)
        self.lock.unlock()
        if read.isError():
            self.log.exception(traceback.format_exception(read))
            return None
        return read

    def _write(self, register, value):
        self.lock.lock()
        wrote = self.client.write_registers(register, value, skip_encode=True)
        self.lock.unlock()
        if wrote.isError():
            self.log.exception(traceback.format_exception(wrote))
            return False
        return True

    def _decode(self, read, data_type, *args, **kwargs):
        decoder = BinaryPayloadDecoder.fromRegisters(read.registers, byteorder=self.byteorder, wordorder=self.wordorder)
        return getattr(decoder, f"decode_{data_type}")(*args, **kwargs)

    def _encode(self, data, data_type, *args, **kwargs):
        builder = BinaryPayloadBuilder(byteorder=self.byteorder, wordorder=self.wordorder)
        getattr(builder, f"add_{data_type}")(data, *args, **kwargs)
        return builder.build()

    def read(self, register, *args, **kwargs):
        if type(register) is str:
            register, s = self.registers[register]
            if not len(args):
                args = [s["dt"], *s.get("a", [])]
            if not len(kwargs):
                kwargs = s.get("k", {})
        if args[0].startswith("16bit_"):
            count = 1
        elif args[0].startswith("32bit_"):
            count = 2
        else:
            raise NotImplementedError(f"data_type {args[0]!r} is not supported")
        return self._decode(self._read(register, count=count), *args, **kwargs)

    def write(self, register, data, *args, **kwargs):
        if type(register) is str:
            register, s = self.registers[register]
            if not len(args):
                args = [s["dt"], *s.get("a", [])]
            if not len(kwargs):
                kwargs = s.get("k", {})
        return self._write(register, self._encode(data, *args, **kwargs))

    # def _get(self, data):
    #     # print("MODBUS", str(int(QThread.currentThreadId())), flush=True)
    #     super()._get(data)

    def __del__(self, event=None):
        self.lock.lock()
        if self.client.is_socket_open():
            self.client.close()
        self.lock.unlock()