#!/usr/bin/env python3
"""The `PRESS Ⓐ` plate over time: does it stay up, pulse, or blink once?

`fast_title_probe.py` answers "is the title up yet" — a threshold crossing. This
logs the **whole series**, because the port's question is about the shape: an
authored `looping_focus_records` entry is deleted if the plate blinks once and
kept if it pulses.

Counter is byte-identical to `is_title.py`. ⚠️ Controls, run before this was
pointed at anything unknown:

    live-title-press-a.png        753   (plate up)
    live-main-menu.png            327   (documented)
    live-title-build4-no-plate.png 159  ← the FLOOR: the title art alone carries
                                          159 green pixels, so 0 is not the
                                          plate-absent value and a series that
                                          bottoms at ~159 is a plate going away,
                                          not a black screen.

🔴 The stream is torn down every RESTART_S. A single long-lived x11grab degrades
to 1.60 fps and then reports a stale frame forever — see `fast_title_probe.py`.

    plate_timeseries.py SECONDS OUT.tsv
"""
import subprocess
import sys
import time

import numpy as np

W, H = 1280, 720
LIMIT = float(sys.argv[1]) if len(sys.argv) > 1 else 300
OUT = sys.argv[2] if len(sys.argv) > 2 else "/dev/stdout"
RESTART_S = 30


def _open():
    return subprocess.Popen(
        ["ffmpeg", "-loglevel", "error", "-f", "x11grab", "-draw_mouse", "0",
         "-video_size", f"{W}x{H}", "-i", ":98", "-r", "6",
         "-f", "rawvideo", "-pix_fmt", "rgb24", "-"],
        stdout=subprocess.PIPE, bufsize=W * H * 3 * 2)


p = _open()
n = W * H * 3
t0 = time.time()
seg = t0
with open(OUT, "w") as f:
    f.write("# t_s\tglyph_px\tsurface_mean\n")
    while time.time() - t0 < LIMIT:
        if time.time() - seg > RESTART_S:
            p.kill(); p = _open(); seg = time.time()
        buf = p.stdout.read(n)
        if len(buf) < n:
            p.kill(); p = _open(); seg = time.time(); continue
        a = np.frombuffer(buf, np.uint8).reshape(H, W, 3).astype(int)
        r, g, b = a[:, :, 0], a[:, :, 1], a[:, :, 2]
        c = int(((g > 130) & (g - r > 45) & (g - b > 45)).sum())
        f.write(f"{time.time()-t0:.3f}\t{c}\t{a.mean():.3f}\n")
        f.flush()
p.kill()