import asyncio
import tempfile
import signal
import os
from pathlib import Path
from dataclasses import dataclass

class Downloader:
    """Class that performs content download."""

    #
    # PUBLIC
    #
    def __init__(self, url: str):
        self._url = url

    async def download_video(self, directory: str | Path) -> Path:
        directory = Path(directory).resolve()
        directory.mkdir(parents=True, exist_ok=True)

        with tempfile.TemporaryDirectory(dir=directory, prefix=".ytdlp-") as tmp:
            proc = await asyncio.create_subprocess_exec(
                "yt-dlp",
                "-f", "bv*+ba/b",
                "-P", f"home:{directory}",
                "-P", f"temp:{tmp}",
                "--no-playlist",
                "--print", "after_move:filepath",
                self._url,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE,
                start_new_session=True,
            )

            try:
                stdout, stderr = await proc.communicate()

            except asyncio.CancelledError:
                try:
                    os.killpg(proc.pid, signal.SIGKILL)
                except ProcessLookupError:
                    pass

                await asyncio.shield(proc.wait())
                raise

            if proc.returncode != 0:
                raise RuntimeError(stderr.decode(errors="replace"))

            return Path(stdout.decode().strip())