"""One-time ROI calibration.

Usage:
    python calibrate.py samples/full_1080p.png          # interactive: drag 10 slot boxes
    python calibrate.py samples/full_1080p.png --check  # draw current config on image

Interactive mode: for each of the 10 hero slots (any order), drag a box around
the portrait (include the whole parallelogram, exclude neighbors), then press
SPACE/ENTER. Press ESC when all 10 are done. Slots are sorted left-to-right
and stored as resolution-independent relative coordinates.
"""

import sys
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parents[1]))

import time

import cv2

from common import load_config, save_config, slot_rect_px


def calibrate(image_path: str) -> None:
    img = cv2.imread(image_path)
    if img is None:
        sys.exit(f"cannot read image: {image_path}")
    ih, iw = img.shape[:2]
    print(f"image size: {iw}x{ih}")
    print("Drag a box per slot (10 total), SPACE/ENTER to confirm each, ESC to finish.")

    rois = cv2.selectROIs("calibrate - drag 10 slots", img, showCrosshair=True)
    cv2.destroyAllWindows()
    if len(rois) != 10:
        sys.exit(f"expected 10 boxes, got {len(rois)} - please rerun")

    rois = sorted(rois.tolist(), key=lambda r: r[0])
    cfg = load_config()
    cfg["slots"] = []
    avg_w = sum(r[2] for r in rois) / 10
    avg_h = sum(r[3] for r in rois) / 10
    cfg["slot_w_rel"] = round(avg_w / ih, 5)
    cfg["slot_h_rel"] = round(avg_h / ih, 5)
    for i, (x, y, w, h) in enumerate(rois):
        cfg["slots"].append(
            {
                "index": i + 1,
                "cx_rel": round((x + w / 2 - iw / 2) / ih, 5),
                "cy_rel": round((y + h / 2) / ih, 5),
            }
        )
    cfg["calibrated_on"] = f"{iw}x{ih} {time.strftime('%Y-%m-%d %H:%M')}"
    save_config(cfg)
    print(f"saved {len(cfg['slots'])} slots to config.json")
    check(image_path)


def check(image_path: str) -> None:
    """Draw configured slot rects onto the image for visual verification."""
    img = cv2.imread(image_path)
    if img is None:
        sys.exit(f"cannot read image: {image_path}")
    ih, iw = img.shape[:2]
    cfg = load_config()
    if not cfg["slots"]:
        sys.exit("config.json has no slots - run calibration first")
    for slot in cfg["slots"]:
        x, y, w, h = slot_rect_px(slot, cfg, iw, ih)
        cv2.rectangle(img, (x, y), (x + w, y + h), (0, 255, 0), 2)
        cv2.putText(img, str(slot["index"]), (x, y - 4), cv2.FONT_HERSHEY_SIMPLEX, 0.6, (0, 255, 0), 2)
    out = "calibrate_check.png"
    cv2.imwrite(out, img)
    print(f"wrote {out} - open it and verify the boxes sit on the 10 portraits")


if __name__ == "__main__":
    if len(sys.argv) < 2:
        sys.exit(__doc__)
    if "--check" in sys.argv:
        check(sys.argv[1])
    else:
        calibrate(sys.argv[1])