from rpi_ws281x import PixelStrip
import atexit


class _LedData(object):
    _led: []

    def __init__(self, channel, size):
        self.size = size
        self.channel = channel

    def __getitem__(self, pos):
        """Return the 24-bit RGB color value at the provided position or slice
        of positions.
        """
        # Handle if a slice of positions are passed in by grabbing all the values
        # and returning them in a list.
        if isinstance(pos, slice):
            return [self._led[n] for n in range(*pos.indices(self.size))]
        # Else assume the passed in value is a number to the position.
        else:
            return self._led[pos]

    def __setitem__(self, pos, value):
        """Set the 24-bit RGB color value at the provided position or slice of
        positions.
        """
        # Handle if a slice of positions are passed in by setting the appropriate
        # LED data values to the provided values.
        if isinstance(pos, slice):
            index = 0
            for n in range(*pos.indices(self.size)):
                self._led[n] = value[index]
                index += 1
            # Else assume the passed in value is a number to the position.
            # else:
            self._led[pos] = value


class FakeStrip(PixelStrip):
    _brightness: int

    def __init__(self, num, pin, freq_hz=800000, dma=10, invert=False,
                 brightness=255, channel=0, strip_type=None, gamma=None):

        if gamma is None:
            # Support gamma in place of strip_type for back-compat with
            # previous version of forked library
            if type(strip_type) is list and len(strip_type) == 256:
                gamma = strip_type
                # strip_type = None
            else:
                gamma = list(range(256))

        # Initialize the channel in use
        self._channel = None
        self._gamma = gamma
        self._brightness = brightness

        # Grab the led data array.
        self._led_data = _LedData(self._channel, num)

        # Substitute for __del__, traps an exit condition and cleans up properly
        atexit.register(self._cleanup)

    def _cleanup(self):
        # Clean up memory used by the library when not needed anymore.
        if self._channel is not None:
            self._channel = None

    def setGamma(self, gamma):
        if type(gamma) is list and len(gamma) == 256:
            self._gamma = gamma

    def begin(self):
        """Initialize library, must be called once before other functions are called."""
        return

    def show(self):
        """Update the display with the data from the LED buffer."""
        return  # render

    def getBrightness(self) -> int:
        return self._brightness

    def setBrightness(self, brightness: int):
        """Scale each LED in the buffer by the provided brightness.
        A brightness of 0 is the darkest and 255 is the brightest.
        """
        self._brightness = brightness

    def numPixels(self):
        """Return the number of pixels in the display."""
        return self._led_data.size