import gzip
import shutil
import subprocess
from pathlib import Path

import httpx

FFMPEG_DIR = Path(__file__).resolve().parents[2] / "tools" / "ffmpeg"
FFMPEG_EXE = FFMPEG_DIR / "ffmpeg.exe"
FFMPEG_URL = "https://github.com/eugeneware/ffmpeg-static/releases/download/b6.1.1/ffmpeg-win32-x64.gz"


def ffmpeg_path() -> Path | None:
    if FFMPEG_EXE.is_file():
        return FFMPEG_EXE
    found = shutil.which("ffmpeg")
    return Path(found) if found else None


def ensure_ffmpeg() -> Path:
    current = ffmpeg_path()
    if current is not None:
        return current
    FFMPEG_DIR.mkdir(parents=True, exist_ok=True)
    archive = FFMPEG_DIR / "ffmpeg-win32-x64.gz"
    try:
        with httpx.Client(follow_redirects=True, timeout=120.0, trust_env=False) as client:
            response = client.get(FFMPEG_URL)
            response.raise_for_status()
            archive.write_bytes(response.content)
        import gzip

        FFMPEG_EXE.write_bytes(gzip.decompress(archive.read_bytes()))
    finally:
        archive.unlink(missing_ok=True)
    if not FFMPEG_EXE.is_file():
        raise RuntimeError("没有找到 ffmpeg")
    return FFMPEG_EXE


def convert_to_mp4(episode_dir: Path, mp4_path: Path) -> None:
    exe = ensure_ffmpeg()
    mp4_path.parent.mkdir(parents=True, exist_ok=True)
    temporary = mp4_path.with_name(f"{mp4_path.stem}.part.mp4")
    completed = subprocess.run(
        [
            str(exe),
            "-y",
            "-allowed_extensions",
            "ALL",
            "-i",
            "video.m3u8",
            "-c",
            "copy",
            "-movflags",
            "+faststart",
            "-f",
            "mp4",
            str(temporary),
        ],
        cwd=episode_dir,
        capture_output=True,
        check=False,
    )
    if completed.returncode != 0 or not temporary.is_file() or temporary.stat().st_size <= 0:
        temporary.unlink(missing_ok=True)
        detail = (completed.stderr or b"").decode("utf-8", "replace")[-400:]
        raise RuntimeError("转换成 MP4 失败" + (f"：{detail}" if detail else ""))
    temporary.replace(mp4_path)


def unused_zip_helper(path: Path) -> None:
    if path.suffix == ".zip":
        with zipfile.ZipFile(path) as archive:
            archive.extractall(path.parent)