import sys
from pathlib import Path

import cv2

from bookmark.camera import CameraSource


def main() -> None:
    device_index = int(sys.argv[1]) if len(sys.argv) > 1 else 0
    output_path = Path(sys.argv[2]) if len(sys.argv) > 2 else Path("reference.jpg")

    camera = CameraSource(device_index=device_index)
    camera.open()
    print("Clear the platform of any book, then press ENTER to capture the reference frame.")
    input()
    frame = camera.read_frame()
    camera.close()

    cv2.imwrite(str(output_path), frame)
    print(f"Reference frame saved to {output_path}")
    print(
        "Next: open the reference image in an editor to note the pixel coordinates of "
        "each size-boundary marker and the guide box, then fill them into config.json's "
        "\"markers\" and \"guide_box\" fields."
    )


if __name__ == "__main__":
    main()