import mimetypes
import subprocess
from pathlib import Path

import http_pool


def download_from_yt(url: str, album_path: Path) -> None:
    '''YouTube-specific cover art downloader.
    See https://git.dc09.ru/DarkCat09/musicdlp/issues/1#issuecomment-202'''

    path = album_path / 'cover.webp'
    if path.exists():
        return

    ret = subprocess.call(
        [
            'ffmpeg',
            '-nostdin',
            '-i', url,
            '-vf', 'crop=ih:ih',
            str(album_path / 'cover.webp'),
        ],
        stdout=subprocess.DEVNULL,
        stderr=subprocess.DEVNULL,
    )

    if ret != 0:
        raise RuntimeError(f'FFmpeg returned {ret} exit code')


def download(url: str, album_path: Path) -> None:
    '''General cover art downloader'''

    resp = http_pool.get().request('GET', url)
    ct = resp.headers['content-type']
    if not ct.startswith('image'):
        raise ValueError('thumbnail is not an image')
    ext = mimetypes.guess_extension(ct) or '.jpg'

    path = album_path / ('cover' + ext)
    if path.exists():
        return

    with path.open('wb') as f:
        f.write(resp.data)