class NeoPixelStrip:
    """SK6812 RGBW driver using built-in neopixel module."""

    def __init__(self, pin_num, led_count):
        import neopixel
        from machine import Pin
        self.np = neopixel.NeoPixel(Pin(pin_num), led_count, bpp=4, timing=1)
        self.led_count = led_count

    def write_rgb(self, pixels):
        """Write list of (R,G,B) tuples. W channel set to 0."""
        for i, (r, g, b) in enumerate(pixels):
            if i >= self.led_count:
                break
            self.np[i] = (r, g, b, 0)
        self.np.write()

    def write_rgbw(self, pixels):
        """Write list of (R,G,B,W) tuples."""
        for i, (r, g, b, w) in enumerate(pixels):
            if i >= self.led_count:
                break
            self.np[i] = (r, g, b, w)
        self.np.write()

    def fill(self, r, g, b, w=0):
        """Fill all pixels with one color."""
        self.np.fill((r, g, b, w))
        self.np.write()

    def clear(self):
        self.fill(0, 0, 0, 0)


class WS2801Strip:
    """WS2801 RGB driver using SPI — no external library needed."""

    def __init__(self, spi_id, clk_pin, dat_pin, led_count):
        from machine import SPI, Pin
        self.spi = SPI(spi_id, baudrate=1000000, polarity=0, phase=0,
                       sck=Pin(clk_pin), mosi=Pin(dat_pin))
        self.led_count = led_count
        self._buf = bytearray(led_count * 3)

    def write_rgb(self, pixels):
        """Write list of (R,G,B) tuples."""
        for i, (r, g, b) in enumerate(pixels):
            if i >= self.led_count:
                break
            off = i * 3
            self._buf[off] = r
            self._buf[off + 1] = g
            self._buf[off + 2] = b
        self.spi.write(self._buf)

    def write_rgbw(self, pixels):
        """Write RGBW tuples — W channel is discarded (WS2801 is RGB only)."""
        for i, (r, g, b, _w) in enumerate(pixels):
            if i >= self.led_count:
                break
            off = i * 3
            self._buf[off] = r
            self._buf[off + 1] = g
            self._buf[off + 2] = b
        self.spi.write(self._buf)

    def fill(self, r, g, b, w=0):
        for i in range(self.led_count):
            off = i * 3
            self._buf[off] = r
            self._buf[off + 1] = g
            self._buf[off + 2] = b
        self.spi.write(self._buf)

    def clear(self):
        self.fill(0, 0, 0)


def create_strip(config):
    """Factory: create the right strip driver from config dict."""
    if config['strip_type'] == 'sk6812':
        return NeoPixelStrip(config['led_pin'], config['led_count'])
    elif config['strip_type'] == 'ws2801':
        return WS2801Strip(config['spi_id'], config.get('spi_clk_pin', 18),
                           config.get('spi_dat_pin', 23), config['led_count'])
    else:
        raise ValueError('Unknown strip_type: ' + config['strip_type'])