#!/usr/bin/env python3
"""Is this screenshot the MAIN MENU or EXTRAS? screen_id.py cannot tell them apart.

Both are dark-blue `GP_TITLE` screens, so `screen_id.py` reports `menu` for
either. This correlates the grab against our own build 5 / build 6 renders and
reports which is closer, plus the margin -- a small margin means "cannot tell",
not "the closer one".

⚠️ These are OUR renders, so this identifies a screen by agreeing with our
decoding. It is a navigation aid for driving the emulator, NOT evidence about the
game. Nothing measured is allowed to rest on it.

    which_title_screen.py <grab.png> [ref_dir]
"""
import sys
import numpy as np
from PIL import Image

def load(p, shape=None):
    im = Image.open(p).convert("RGB")
    a = np.asarray(im, dtype=float)
    return a

def main():
    grab = load(sys.argv[1])
    d = sys.argv[2] if len(sys.argv) > 2 else "/sylph-home/re/ref"
    # The game surface sits at y=45 ONLY in a full 1280x720 display frame; a
    # 1279x675 grab is the surface already. Hard-coding the 45 made this tool fail
    # its own control -- it called the main menu "extras" and extras "main_menu",
    # because two of the three reference captures are surface-sized.
    off = 45 if grab.shape[0] >= 716 else 0
    best = []
    for b, name in ((5, "main_menu"), (6, "extras")):
        r = load(f"{d}/build{b}.png")
        h = min(grab.shape[0] - off, r.shape[0]); w = min(grab.shape[1], r.shape[1])
        g = grab[off:off + h, :w]; rr = r[:h, :w]
        best.append((float(np.sqrt(((g - rr) ** 2).mean())), name))
    best.sort()
    margin = best[1][0] - best[0][0]
    print(f"{best[0][1]}  rmse={best[0][0]:.2f}  (other {best[1][1]} {best[1][0]:.2f}, margin {margin:.2f})")
    return 0

if __name__ == "__main__":
    raise SystemExit(main())