#!/usr/bin/env python3
"""Record a scan session: scan mode + auto-exposure, saving every frame (fixed
640x296 grayscale PNG) and its embedded sensor record to records.csv.
Mouse mode is restored on exit (also on Ctrl-C)."""
import argparse
import csv
import os
import sys
import time

sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
sys.stderr = os.fdopen(os.dup(2), "w")
os.dup2(os.open(os.devnull, os.O_WRONLY), 2)  # silence libjpeg warnings

import cv2  # noqa: E402
import numpy as np  # noqa: E402

from myscan.frame import fix_and_extract  # noqa: E402
from myscan.xu import XU  # noqa: E402


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("-d", "--duration", type=float, default=20)
    ap.add_argument("-o", "--out", default="scan")
    ap.add_argument("--video", default="/dev/video4")
    ap.add_argument("--target", type=float, default=150, help="auto-exposure target mean brightness")
    ap.add_argument("--exposure", type=int, help="fixed E6 value instead of auto-exposure")
    a = ap.parse_args()
    os.makedirs(a.out, exist_ok=True)

    x = XU(a.video)
    e6 = a.exposure or 40
    rows = []
    try:
        if not (x.disable_mouse()[0] and x.mcu_write_verified(0x2D, 0x60)
                and x.mcu_write_verified(0xE7, 0x28) and x.mcu_write_verified(0xE6, e6)
                and x.start_scan()[0]):
            sys.exit("failed to enter scan mode")
        cap = cv2.VideoCapture(a.video, cv2.CAP_V4L2)
        cap.set(cv2.CAP_PROP_FOURCC, cv2.VideoWriter_fourcc(*"MJPG"))
        cap.set(cv2.CAP_PROP_CONVERT_RGB, 0)
        print(f"scanning for {a.duration:.0f}s -> {a.out}/  (Ctrl-C to stop early)", flush=True)
        t0, n, last = time.time(), 0, 0.0
        while time.time() - t0 < a.duration:
            ok, f = cap.read()
            if not ok:
                continue
            t = time.time() - t0
            clean, rec = fix_and_extract(f.tobytes())
            im = cv2.imdecode(np.frombuffer(clean, np.uint8), cv2.IMREAD_GRAYSCALE)
            if im is None or rec is None:
                continue
            cv2.imwrite(f"{a.out}/f{n:05d}.png", im)
            mean = float(im.mean())
            rows.append([round(t, 4), n, rec.counter, *rec.v, rec.b14, rec.b15, rec.b16, rec.flags, e6,
                         round(mean, 1), rec.raw.hex()])
            # Proportional auto-exposure every 3 frames (brightness is ~linear in E6).
            if a.exposure is None and n % 3 == 0 and mean > 1:
                new = int(min(255, max(2, round(e6 * (a.target / mean) ** 0.7))))
                if new != e6 and x.mcu_write_verified(0xE6, new):
                    e6 = new
            if t - last >= 1:
                print(f"t={t:5.1f}s frames={n:4d} E6={e6:3d} bright={mean:5.1f} "
                      f"l1=({rec.v[0]:#06x},{rec.v[1]:#06x}) l2=({rec.v[3]:#06x},{rec.v[4]:#06x}) "
                      f"sq={rec.b14},{rec.b15} flags={rec.flags:05b}", flush=True)
                last = t
            n += 1
        cap.release()
    except KeyboardInterrupt:
        pass
    finally:
        print("restore mouse mode:", x.enable_mouse()[0])
        with open(f"{a.out}/records.csv", "w", newline="") as fh:
            w = csv.writer(fh)
            w.writerow(["t", "frame", "counter", "v0", "v1", "v2", "v3", "v4", "v5",
                        "b14", "b15", "b16", "flags", "e6", "brightness", "raw"])
            w.writerows(rows)
        print(f"{len(rows)} frames saved to {a.out}/")


if __name__ == "__main__":
    main()