import utime


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

    def run(self, preset):
        self.driver.off()

        # Get colors from preset
        colors = preset.c
        if not colors:
            colors = [(255, 255, 255)]

        color_index = 0
        cycle_start = utime.ticks_ms()

        # State machine based pulse using a single generator loop
        while True:
            # Read current timing parameters from preset
            attack_ms = max(0, int(preset.n1))  # Attack time in ms
            hold_ms = max(0, int(preset.n2))    # Hold time in ms
            decay_ms = max(0, int(preset.n3))   # Decay time in ms
            delay_ms = max(0, int(preset.d))

            total_ms = attack_ms + hold_ms + decay_ms + delay_ms
            if total_ms <= 0:
                total_ms = 1

            now = utime.ticks_ms()
            elapsed = utime.ticks_diff(now, cycle_start)

            base_color = colors[color_index % len(colors)]

            if elapsed < attack_ms and attack_ms > 0:
                # Attack: fade 0 -> 1
                factor = elapsed / attack_ms
                color = tuple(int(c * factor) for c in base_color)
                self.driver.fill(self.driver.apply_brightness(color, preset.b))
            elif elapsed < attack_ms + hold_ms:
                # Hold: full brightness
                self.driver.fill(self.driver.apply_brightness(base_color, preset.b))
            elif elapsed < attack_ms + hold_ms + decay_ms and decay_ms > 0:
                # Decay: fade 1 -> 0
                dec_elapsed = elapsed - attack_ms - hold_ms
                factor = max(0.0, 1.0 - (dec_elapsed / decay_ms))
                color = tuple(int(c * factor) for c in base_color)
                self.driver.fill(self.driver.apply_brightness(color, preset.b))
            elif elapsed < total_ms:
                # Delay phase: LEDs off between pulses
                self.driver.fill((0, 0, 0))
            else:
                # End of cycle, move to next color and restart timing
                color_index += 1
                cycle_start = now
                if not preset.a:
                    break
                # Skip drawing this tick, start next cycle
                yield
                continue

            # Yield once per tick
            yield