#!/usr/bin/env python3
"""Sample a candidate `REMAINING OB` address paired with a HUD screenshot.

`structures/mission-objective-counter.md` found the counter at a guest VA in one
Stage 02 run and left cross-run stability untested. Testing it needs the RAM word
and the HUD digits from the SAME moment, which is the trap that already cost one
pass: the value moves between the memory read and the screenshot that is supposed
to confirm it. So every sample reads the word, takes the shot, and reads the word
AGAIN — a row whose two reads disagree is thrown away rather than believed.

The HUD counter is cropped out of each shot (the region is fixed: the plate sits
in the top-right, x >= 0.72 W, 0.32 H .. 0.45 H) so the digits can be read without
squinting at a 1280x720 frame.

Usage: ob_sample.py <va> <out.csv> <shot-dir> <tag> [interval_s] [count]
"""
import os
import struct
import subprocess
import sys
import time

sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
import gmem  # noqa: E402

CROP = (0.72, 0.32, 1.0, 0.45)   # HUD "REMAINING OB" plate, fractions of W/H


def read_word(path, off):
    try:
        with open(path, "rb") as f:
            f.seek(off)
            b = f.read(4)
        return struct.unpack(">I", b)[0] if len(b) == 4 else None
    except OSError:
        return None


def crop_hud(shot, out):
    try:
        from PIL import Image
    except ImportError:
        return False
    im = Image.open(shot)
    w, h = im.size
    c = im.crop((int(CROP[0] * w), int(CROP[1] * h), int(CROP[2] * w), int(CROP[3] * h)))
    c.resize((c.width * 2, c.height * 2)).save(out)
    return True


def main():
    va = int(sys.argv[1], 0)
    out_csv, shot_dir, tag = sys.argv[2], sys.argv[3], sys.argv[4]
    interval = float(sys.argv[5]) if len(sys.argv) > 5 else 30.0
    count = int(sys.argv[6]) if len(sys.argv) > 6 else 8

    off = gmem.va_to_off(va)
    mem = gmem.mem_path()
    os.makedirs(shot_dir, exist_ok=True)
    t0 = time.time()
    with open(out_csv, "w") as f:
        f.write("t_s,ram_before,ram_after,stable,shot\n")
        for i in range(count):
            before = read_word(mem, off)
            shot = os.path.join(shot_dir, f"{tag}-{i:02d}.png")
            subprocess.run(["screenshot", shot], stdout=subprocess.DEVNULL,
                           stderr=subprocess.DEVNULL)
            after = read_word(mem, off)
            crop_hud(shot, os.path.join(shot_dir, f"{tag}-{i:02d}-ob.png"))
            row = (f"{time.time()-t0:.1f},{before},{after},"
                   f"{int(before is not None and before == after)},{shot}")
            f.write(row + "\n")
            f.flush()
            print(row, flush=True)
            time.sleep(max(0.0, interval - (time.time() - t0) % interval))


if __name__ == "__main__":
    main()