class ModbusError(Exception):
    """ Base class for all Modbus related exception. """
    pass


class IllegalFunctionError(ModbusError):
    """ The function code received in the request is not an allowable action for
    the server.

    """
    error_code = 1

    def __str__(self):
        return 'Function code is not an allowable action for the server.'


class IllegalDataAddressError(ModbusError):
    """ The data address received in the request is not an allowable address for
    the server.
    """
    error_code = 2

    def __str__(self):
        return self.__doc__


class IllegalDataValueError(ModbusError):
    """ The value contained in the request data field is not an allowable value
    for the server.

    """
    error_code = 3

    def __str__(self):
        return self.__doc__


class ServerDeviceFailureError(ModbusError):
    """ An unrecoverable error occurred. """
    error_code = 4

    def __str__(self):
        return 'An unrecoverable error occurred.'


class AcknowledgeError(ModbusError):
    """ The server has accepted the requests and it processing it, but a long
    duration of time will be required to do so.
    """
    error_code = 5

    def __str__(self):
        return self.__doc__


class ServerDeviceBusyError(ModbusError):
    """ The server is engaged in a long-duration program command. """
    error_code = 6

    def __str__(self):
        return self.__doc__


class MemoryParityError(ModbusError):
    """ The server attempted to read record file, but detected a parity error
    in memory.

    """
    error_code = 8

    def __repr__(self):
        return self.__doc__


class GatewayPathUnavailableError(ModbusError):
    """ The gateway is probably misconfigured or overloaded. """
    error_code = 10

    def __repr__(self):
        return self.__doc__


class GatewayTargetDeviceFailedToRespondError(ModbusError):
    """ Didn't get a response from target device. """
    error_code = 11

    def __repr__(self):
        return self.__doc__

error_code_to_exception_map = {
    IllegalFunctionError.error_code: IllegalFunctionError,
    IllegalDataAddressError.error_code: IllegalDataAddressError,
    IllegalDataValueError.error_code: IllegalDataValueError,
    ServerDeviceFailureError.error_code: ServerDeviceFailureError,
    AcknowledgeError.error_code: AcknowledgeError,
    ServerDeviceBusyError.error_code: ServerDeviceBusyError,
    MemoryParityError.error_code: MemoryParityError,
    GatewayPathUnavailableError.error_code: GatewayPathUnavailableError,
    GatewayTargetDeviceFailedToRespondError.error_code:
        GatewayTargetDeviceFailedToRespondError
}