#!/usr/bin/env -S python3.12

from pathlib import Path
import logging
import subprocess
import argparse

logger = logging.getLogger(__name__)


def hardcode_subs(
    video_path: Path,
    subtitle_path: Path,
    lang: str,
    save_path: Path | None = None,
    resolution: str | None = None,
    quality: float | None = None,
    font_size: int = 40,
) -> Path:
    if not save_path:
        save_path = video_path.with_name(f"{video_path.stem}.{lang}.hardcoded.mp4")
    vf_filters = [f"subtitles='{subtitle_path}:force_style=Fontsize={font_size}'"]
    if resolution:
        resolution_map = {"1080p": 1920, "720p": 1280, "480p": 854}
        max_width = resolution_map.get(resolution)
        if max_width:
            vf_filters.append(f"scale='min({max_width},iw)':-2")
    vf = ",".join(vf_filters)
    crf = str(quality) if quality else "35"
    cmd = [
        "ffmpeg",
        "-y",
        "-hwaccel",
        "videotoolbox",
        "-i",
        str(video_path),
        "-vf",
        vf,
        "-c:v",
        "h264_videotoolbox",
        "-crf",
        crf,
        "-c:a",
        "copy",
        str(save_path),
    ]
    logger.info(f"Hardcoding subtitles into video: {save_path.name}")
    subprocess.run(cmd, check=True)
    return save_path


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Hardcode subtitles into a video.", formatter_class=argparse.ArgumentDefaultsHelpFormatter)
    parser.add_argument("video", type=Path, help="Path to the video file")
    parser.add_argument("subtitle", type=Path, help="Path to the subtitle file")
    parser.add_argument("--out", "-o", type=Path, help="Path to the output video file")
    parser.add_argument("--lang", default="en", help="Language code for subtitles")
    parser.add_argument(
        "--resolution",
        choices=["1080p", "720p", "480p"],
        help="Set output video resolution (max width)",
    )
    parser.add_argument(
        "--quality",
        "-q",
        type=float,
        default=35,
        help="Set CRF quality factor (lower is better, default 35)",
    )
    parser.add_argument(
        "--font-size",
        type=int,
        default=40,
        help="Font size for hardcoded subtitles",
    )
    return parser.parse_args()


def main():
    logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s: %(message)s")
    args = parse_args()
    if not args.video.exists():
        raise FileNotFoundError(f"Video file not found: {args.video}")
    if not args.subtitle.exists():
        raise FileNotFoundError(f"Subtitle file not found: {args.subtitle}")

    save_path = args.out or args.video.with_name(f"{args.video.stem}.{args.lang}.hardcoded.mp4")
    hardcoded_video = hardcode_subs(
        video_path=args.video,
        subtitle_path=args.subtitle,
        lang=args.lang,
        save_path=save_path,
        resolution=args.resolution,
        quality=args.quality,
        font_size=args.font_size,
    )
    logging.info(f"Hardcoded video saved at: {hardcoded_video}")


if __name__ == "__main__":
    main()