import math
import time

import serial


def calculateCRC(data):
    CRC16table = (
        0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
        0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
        0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
        0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
        0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
        0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
        0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
        0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
        0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
        0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
        0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
        0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
        0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
        0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
        0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
        0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
        0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
        0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
        0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
        0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
        0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
        0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
        0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
        0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
        0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
        0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
        0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
        0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
        0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
        0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
        0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
        0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040
    )
    crc = 0xFFFF

    for c in data:
        crc = (crc >> 8) ^ CRC16table[(c ^ crc) & 0xFF]

    msb = (crc >> 8) & 0xFF
    lsb = crc & 0xFF
    return (lsb << 8) + msb


def writeReading(slave, func_code, starting_address, total_size):
    msg_bytearray = bytearray()
    msg_bytearray.append(slave.getSlaveID())
    msg_bytearray.append(func_code)
    msg_bytearray.append(starting_address >> 8)
    msg_bytearray.append(starting_address & 0xFF)
    msg_bytearray.append(total_size >> 8)
    msg_bytearray.append(total_size & 0xFF)
    crc = calculateCRC(msg_bytearray)
    msg_bytearray.append(crc >> 8)
    msg_bytearray.append(crc & 0xFF)
    slave.startCommunication()
    slave.serial.write(msg_bytearray)
    print(msg_bytearray)


class Slave:
    def __init__(self, slaveID, port='COM1', baudrate=9600, parity=serial.PARITY_NONE, byteSize=8, stopBits=1):
        self._slaveID = slaveID
        self._port = port
        self._serial = serial.Serial(
            port=port,
            baudrate=baudrate,
            parity=parity,
            bytesize=byteSize,
            stopbits=stopBits,
            timeout=1,
        )

    def getSlaveID(self):
        return self._slaveID

    def getPort(self):
        return self._port

    def startCommunication(self):
        if not self._serial.is_open:
            self._serial.open()
        self.serial.reset_input_buffer()
        self.serial.reset_output_buffer()

    @property
    def serial(self):
        return self._serial


class Master:
    def __init__(self):
        self._slaves = dict()
        self._log = ""
        self._log_count = 0

    def _printToLog(self, string):
        self._log_count += 1
        self._log += str(self._log_count) + string + "\n"

    def printLog(self):
        print(self._log)

    def addSlave(self, slave):
        if slave.getSlaveID() not in self._slaves.keys():
            self._printToLog("Slave " + str(slave.getSlaveID) + " added to slaves dictionary." + str(slave.getPort()))
            slave.serial.reset_input_buffer()
            slave.serial.reset_output_buffer()
            self._slaves[slave.getSlaveID()] = slave
        else:
            self._printToLog("Slave " + slave.getSlaveID + "already in dictionary")

    # FC01
    def readCoils(self, slaveID, starting_address, total_size):
        slave = self._slaves[slaveID]
        writeReading(slave, 0x01, starting_address, total_size)
        no_of_bytes = math.ceil(total_size / 8)
        responseFrameSize = 5 + no_of_bytes
        resp_coil_array = []
        resp_bytearray = slave.serial.read(responseFrameSize)
        print(resp_bytearray)
        slave.serial.flush()

        get_bin = lambda x, n: format(x, 'b').zfill(n)
        space_holder = no_of_bytes * 8 - total_size

        for i in range(3, responseFrameSize - 2):
            coils = get_bin(resp_bytearray[i], 8)
            for j in range(8):
                if i == responseFrameSize - 3:
                    resp_coil_array.append(coils[j + space_holder])
                    if (j + space_holder + 1) is len(coils):
                        continue
                else:
                    resp_coil_array.append(coils[j])

        return resp_coil_array

    # FC02
    def readInputStatus(self, slaveID, starting_address, total_size):
        return self.readCoils(slaveID, starting_address, total_size)

    # FC03
    def readHoldingRegisters(self, slaveID, starting_address, total_size):
        slave = self._slaves[slaveID]
        writeReading(slave, 0x03, starting_address, total_size)

        no_of_bytes = total_size * 2
        responseFrameSize = no_of_bytes + 5

        resp_bytearray = slave.serial.read(responseFrameSize)
        print(resp_bytearray)
        slave.serial.flush()
        resp_reg_array = []

        for i in range(3, responseFrameSize - 2, 2):
            resp_reg_array.append((resp_bytearray[i] << 8) | resp_bytearray[i + 1])

        crc = calculateCRC(resp_bytearray[:responseFrameSize - 2])
        if crc is not ((resp_bytearray[responseFrameSize - 2] << 8) | resp_bytearray[responseFrameSize - 1]):
            ValueError("CRC ERROR")
        return resp_reg_array

    # FC04
    def readInputRegisters(self, slaveID, starting_address, total_size):
        slave = self._slaves[slaveID]
        return self.readHoldingRegisters(slave, starting_address, total_size)

    # FC05
    def forceSingleCoil(self, slaveID, address, value):
        slave = self._slaves[slaveID]
        return writeReading(slave, 0x05, address, value)

    # FC06
    def presetSingleRegister(self, slaveID, address, value):
        slave = self._slaves[slaveID]
        return writeReading(slave, 0x06, address, value)

    # FC15
    def forceMultipleCoils(self):
        return

    # FC16
    def presetMultipleRegisters(self):
        return
