#!/usr/bin/env python3
"""Is a modal YES/NO dialog on screen?

Written because `wait_screen.sh --tap A` BLIND-taps A, and on this game's
"Load game?" dialog the cursor starts on **NO** — so a blind tap answers NO,
drops back to the save list, and the next tap reopens the dialog. That is a
stable oscillation, and it burned three consecutive 300 s boots as
"NO readyroom" while d-pad and A both worked perfectly.

The game dims the whole frame behind a modal, so the dialog is detectable
without knowing which dialog it is: sample the band where the modal sits and
compare its brightness against the undimmed screen.

Measured on the LOAD GAME save list (1279x675):

    save list, no dialog     mean 59.0 / 62.4   p95 164 / 199
    "Load game?" dialog up   mean 34.4          p95 113

so the threshold sits at 45. Used ONLY to decide whether tapping A is safe:
with a dialog up, A is the affirmative/OK button; without one, A may mean
something destructive like "open the dialog again".

⚠️ Calibrated on 1 positive and 2 negatives — thin. Widen it as runs collect
more frames.

Usage: dialog_up.py <png>     -> prints metrics, exit 0 if a dialog is up
"""
import sys

import numpy as np
from PIL import Image

THRESHOLD = 45.0


def metric(path):
    im = np.asarray(Image.open(path).convert("L"), dtype=float)
    h, w = im.shape
    box = im[int(h * 0.33):int(h * 0.48), int(w * 0.28):int(w * 0.72)]
    return float(box.mean()), float(np.percentile(box, 95))


if __name__ == "__main__":
    mean, p95 = metric(sys.argv[1])
    up = mean < THRESHOLD
    print("%s mean=%.1f p95=%.1f threshold=%.0f" %
          ("dialog" if up else "no-dialog", mean, p95, THRESHOLD))
    sys.exit(0 if up else 1)