"""Try auto-detection of L-shape targets on each video and save JSON sidecars.

Useful for:
- videos that DO have visible black-circle targets (saves manual clicks);
- as a smoke test of the whole pipeline before running the picker.

Failure is silent — videos that fail auto-detection are simply not written
to disk, leaving them for the manual `pick_targets.py` tool.

Output JSON has the same shape as the manual picker's so `track_videos.py`
can consume either.
"""

from __future__ import annotations

import argparse
import datetime as dt
import json
import logging
import sys
from pathlib import Path

import cv2
import numpy as np
import pandas as pd

# ethoscope source tree
sys.path.insert(0, "/home/gg/Code/ethoscope_project/ethoscope/src/ethoscope")

from config import INVENTORY_CSV, TARGETS_DIR  # noqa: E402

from ethoscope.roi_builders.target_roi_builder import TargetGridROIBuilder  # noqa: E402


def detect_one(video_path: Path, frame_idx: int) -> tuple[list[list[int]], int] | None:
    """Run ethoscope target detection on one frame; return (points, frame_idx) or None."""
    cap = cv2.VideoCapture(str(video_path))
    if not cap.isOpened():
        return None
    n = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
    if n > 0 and frame_idx >= n:
        frame_idx = max(0, n - 1)
    cap.set(cv2.CAP_PROP_POS_FRAMES, frame_idx)
    ok, frame = cap.read()
    cap.release()
    if not ok or frame is None:
        return None

    # The detector expects a single-channel image (grey) like ethoscope cameras produce.
    if frame.ndim == 3:
        gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    else:
        gray = frame

    # We don't actually need a fully-configured grid here — _find_target_coordinates
    # alone gives us the 3 reference points.
    builder = TargetGridROIBuilder(n_rows=2, n_cols=3)
    try:
        ref = builder._find_target_coordinates(gray)
    except Exception as e:
        logging.debug(f"detection failed for {video_path.name}: {e}")
        return None
    if ref is None:
        return None
    return [[int(p[0]), int(p[1])] for p in ref], frame_idx


def main() -> None:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--frame", type=int, default=125)
    parser.add_argument("--limit", type=int, default=None)
    parser.add_argument("--video", type=str, default=None,
                        help="run on a single video path (skips inventory)")
    parser.add_argument("--overwrite", action="store_true",
                        help="overwrite existing JSON sidecars")
    args = parser.parse_args()

    TARGETS_DIR.mkdir(parents=True, exist_ok=True)

    if args.video:
        videos = [Path(args.video)]
    else:
        if not INVENTORY_CSV.exists():
            sys.exit("Inventory missing — run build_video_inventory.py first.")
        inv = pd.read_csv(INVENTORY_CSV)
        todo = inv[inv["in_xlsx"] & ~inv["already_tracked"]]
        videos = [Path(p) for p in todo["mp4_path"].tolist()]
        if args.limit:
            videos = videos[: args.limit]

    n_ok = n_fail = n_skip = 0
    for v in videos:
        out = TARGETS_DIR / f"{v.stem}.json"
        if out.exists() and not args.overwrite:
            n_skip += 1
            continue
        result = detect_one(v, args.frame)
        if result is None:
            n_fail += 1
            print(f"  fail: {v.name}")
            continue
        points, used_frame = result
        out.write_text(json.dumps({
            "video_path": str(v),
            "frame_index": int(used_frame),
            "reference_points": points,
            "order": ["top", "corner", "left"],
            "picked_at": dt.datetime.now().isoformat(timespec="seconds"),
            "method": "auto",
        }, indent=2))
        n_ok += 1
        print(f"  ok:   {v.name}  →  {points}")

    print(f"\nDone. ok={n_ok}  fail={n_fail}  skipped(existing)={n_skip}")


if __name__ == "__main__":
    logging.basicConfig(level=logging.WARNING, format="%(levelname)s %(message)s")
    main()