#!/usr/bin/env python3
import argparse
import sys
from pathlib import Path

import cv2 as cv


parser = argparse.ArgumentParser(description="Capture frames from a recorded video.")
parser.add_argument("video", type=Path, help="path to a recorded video file")
parser.add_argument("--frames", type=int, default=60, help="number of frames to capture")
args = parser.parse_args()

if not args.video.is_file():
    sys.exit(f"Video file not found: {args.video}")
if args.frames < 1:
    sys.exit("Frame count must be at least 1")

capture = cv.VideoCapture(str(args.video))
if not capture.isOpened():
    sys.exit(f"Cannot open video: {args.video}")

backend = capture.getBackendName()
frames_captured = 0
frame_size = None

try:
    while frames_captured < args.frames:
        ok, frame = capture.read()
        if not ok or frame is None:
            sys.exit(
                f"Cannot read frame {frames_captured + 1} from {args.video}"
            )

        frames_captured += 1
        frame_size = (frame.shape[1], frame.shape[0])
finally:
    capture.release()

width, height = frame_size
print(f"Video: {args.video}")
print(f"Backend: {backend}")
print(f"Frames captured: {frames_captured}")
print(f"Frame size: {width}x{height}")