"""Twinkle NeoPixel demo — self-contained (stdlib + simulated hardware only)."""

import random
import time

from machine import Pin
import neopixel

# --- helpers


def _clamp(channel: int) -> int:
    return max(0, min(255, int(channel)))


def twinkle_frame(
    led_count: int,
    frame: int,
    base=(0, 0, 8),
    sparkle=(255, 255, 180),
    sparkles: int = 3,
    seed: int = 1337,
):
    if led_count <= 0:
        return []
    out = [tuple(_clamp(v) for v in base) for _ in range(led_count)]
    rng = random.Random(seed + frame)
    for _ in range(min(max(0, sparkles), led_count)):
        idx = rng.randrange(led_count)
        out[idx] = tuple(_clamp(v) for v in sparkle)
    return out


# --- demo

NUM_LEDS = 16

np = neopixel.NeoPixel(Pin(4), NUM_LEDS)

for frame in range(120):
    frame_colors = twinkle_frame(
        len(np),
        frame,
        base=(0, 0, 6),
        sparkle=(255, 210, 130),
        sparkles=3,
    )
    for i, color in enumerate(frame_colors):
        np[i] = color
    np.write()
    time.sleep(0.08)

np.fill((0, 0, 0))
np.write()