import sartoriusb

from sartorius_logger.datalogger import DataLogger


class DummyLogger(DataLogger):
    """ A DataLogger implementation for testing """

    def __init__(self, *args, **kargs):
        super().__init__("log/file.txt", end="")
        self.handle = StubFile()

    def open(self):
        """ simulates opening the log file for writing """
        pass

    def close(self):
        """ simulates closing the log file for writing """
        pass


class StubFile:
    """ a stub file handle that captures everything written to it """

    def __init__(self):
        self.captured = []

    def write(self, data):
        """ simulates a filehandle write """
        self.captured.append(data)

    def __eq__(self, other):
        """ quick way of comparing the captured output to something other """
        return self.captured == other


class DummyScale:
    """ simulates a sartoriusb.SartoriusUSB class """

    _responses = {
        sartoriusb.CMD_INFO_TYPE: "Model:        Quintix-1\r\n",
        sartoriusb.CMD_INFO_SNR: "SerialNumber:    0815  \r",
        sartoriusb.CMD_INFO_VERSION_SCALE: "ScaleVersion    beta1\n",
        sartoriusb.CMD_INFO_VERSION_CONTROL_UNIT: "Version.command  1.2.3",
    }

    _measurements = [
        "G     +    850.1    \r\n",
        "G     +    851.0    \r\n",
        "G     +    852.2    \r\n",
        "G     +    853.0 mg \r\n",
        "G     +    854.4 mg \r\n",
        "G     +    857.0 mg \r\n",
        "G     +    857.0 mg \r\n",
        "G     +    858.7 mg \r\n",
        "G     +    859.0 mg \r\n",
        "G     -   1000.0 mg \r\n",
        "      Low           \r\n",
        "G            0.0    \r\n",
        "G            0.0 mg \r\n",
    ]

    def __init__(self, *args, measurements=None, **kargs):
        """ intializes the dummy scale

        :params measurements: overides for the build in measurements
        :params responses: overides for the build in responses
        """
        if measurements is None:
            self.measurements = self._measurements.copy()
        else:
            self.measurements = measurements
        self.responses = self._responses.copy()
        self.iterator = iter(self.measurements)

    def get(self, command):
        """ simulates the get() method """
        response = self.responses.get(command, False)
        return [response] if response else []

    def measure(self):
        """ simulates the measure() method """
        try:
            value = next(self.iterator)
            return sartoriusb.parse_measurement(value)
        except StopIteration:
            return sartoriusb.Measurement(
                None, None, None, None, "Connection Timeout"
            )

    def __enter__(self):
        return self

    def __exit__(self, *args, **kargs):
        pass