import random
import utime


class Flicker:
    def __init__(self, driver):
        self.driver = driver

    def run(self, preset):
        """Random brightness between n1 (min) and b (max); delay d ms between updates."""
        colors = preset.c if preset.c else [(255, 255, 255)]
        color_index = 0
        last_update = utime.ticks_ms()

        def brightness_bounds():
            lo = max(0, min(255, int(preset.n1)))
            hi = max(0, min(255, int(preset.b)))
            if lo > hi:
                lo, hi = hi, lo
            return lo, hi

        if not preset.a:
            lo, hi = brightness_bounds()
            level = random.randint(lo, hi)
            base = colors[color_index % len(colors)]
            self.driver.fill(self.driver.apply_brightness(base, level))
            yield
            return

        while True:
            current_time = utime.ticks_ms()
            delay_ms = max(1, int(preset.d))
            lo, hi = brightness_bounds()
            if utime.ticks_diff(current_time, last_update) >= delay_ms:
                level = random.randint(lo, hi)
                base = colors[color_index % len(colors)]
                self.driver.fill(self.driver.apply_brightness(base, level))
                color_index += 1
                last_update = utime.ticks_add(last_update, delay_ms)
            yield