import struct
from .CRC16 import modbus_crc16


def get_bit(byte, position):
    return (byte >> position) & 1


class IdiBusMES:
    def __init__(self, data: bytearray):
        if len(data) == 0:
            raise TypeError("Data is an empty bytearray")
        self.data = data
    def validate(self):
        if self.getCRC() != modbus_crc16(self.data[0:-2]):
            return -1
        else:
            return 0
    def getAddress(self):
        return int(self.data[0])
    def getCRC(self):
        return self.data[-2::]
    def __repr__(self):
        return f"Addr:{self.getAddress()}, Body:{self.data[1::]}"
class IdiBusMMESParser(IdiBusMES):
    def __init__(self, data: bytearray):
        super().__init__(data)
    def getMMPS(self):
        return self.data[1]
    def getLongMes(self):
        return get_bit(int(self.data[1]), 0)
    def getMesType(self):
        return get_bit(int(self.data[1]), 1)
    def getAlarm(self):
        return get_bit(int(self.data[1]), 6)
    def getEncStatus(self):
        return get_bit(int(self.data[1]), 7)
    def getDEV(self):
        return int(self.data[2])
    def getCHAN(self):
        return int(self.data[3])
    def getCMD(self):
        return int(self.data[4])
    def getData(self):
        return self.data[4:-2]

class IdiBusMMESGParser(IdiBusMES):
    def __init__(self, data: bytearray):
        super().__init__(data)
    def getMMPS(self):
        return int(self.data[1])
    def getCMD(self):
        return int(self.data[2])
    def getData(self):
        return self.data[3:-2]
class IdiBusSMESParser(IdiBusMES):
    def __init__(self, data: bytearray):
        super().__init__(data)
    def getSPDU(self):
        return int(self.data[1])
    def getErrorBit(self):
        return get_bit(self.data[1], 0)
    def getLongMessage(self):
        return get_bit(self.data[1], 1)
    def getErrcode(self):
        return int(self.data[2])
    def getData(self):
        return self.data[3:-2]
    def getDataStruct(self, format_string):
        try:
            unpacked = struct.unpack(format_string, self.getData())
            return unpacked
        except struct.error as e:
            print(f"Parse error: {e}. got len {len(self.getData())}")
            return None
        except UnicodeDecodeError as e:
            print(f"Parse error: {e}")
            return None
class IdiBusDeviceInfoParser():
    # Формат: 'B H I f 10s'
    # B - unsigned char (1 байт)
    # H - unsigned short (2 байта)
    # I - unsigned int (4 байта)
    # f - float (4 байта)
    # 10s - строка из 10 байт
    format_string = '<B 3s 6s 3s 2B 7s 6s 2B I'
    def __init__(self, data: bytearray):
        if len(data) == 0:
            raise TypeError("Data is an empty bytearray")
        self.data = data
        #print(data[-4::])
    def getStruct(self):
        try:
            unpacked = struct.unpack(self.format_string, self.data)
            packed = {
                'Padding': unpacked[0],
                'GS1_country': unpacked[1].decode('utf-8'),
                'GS1_company': unpacked[2].decode('utf-8'),
                'ModuleType': unpacked[3].decode('utf-8'),
                'HW_revison': str(unpacked[4]) +"." + str(unpacked[5]),
                'SN': unpacked[6].decode('utf-8'),
                'MAC': unpacked[7].decode('utf-8'),
                'SW': str(unpacked[8]) + "." + str(unpacked[9]),
                'AppCRC': hex(unpacked[10]),
            }
            return packed
        except struct.error as e:
            print(f"Parse error: {e}")
            return None
        except UnicodeDecodeError as e:
            print(f"Parse error: {e}")
            return None