import re

from ytmusicapi import YTMusic

ytmusic = YTMusic()


def extract_playlist_id(url: str) -> str:
    """Extract playlist ID from a YouTube Music playlist URL."""
    match = re.search(r"[?&]list=([A-Za-z0-9_-]+)", url)
    if not match:
        raise ValueError("Invalid YouTube Music playlist URL")
    return match.group(1)


def get_playlist_tracks(playlist_url: str) -> tuple[str, str | None, list[dict]]:
    """Fetch playlist info and tracks from a public YouTube Music playlist.

    Returns (playlist_name, playlist_image_url, tracks).
    Each track dict has: title, artist, album, youtube_id, image_url.
    """
    playlist_id = extract_playlist_id(playlist_url)
    playlist = ytmusic.get_playlist(playlist_id, limit=None)

    name = playlist.get("title", playlist_id)
    image_url = None
    thumbnails = playlist.get("thumbnails")
    if thumbnails:
        image_url = thumbnails[-1].get("url")

    tracks = []
    for item in playlist.get("tracks", []):
        artists = item.get("artists") or []
        artist_name = ", ".join(a.get("name", "") for a in artists if a.get("name"))

        album_name = None
        album = item.get("album")
        if album:
            album_name = album.get("name")

        thumb_url = None
        thumbs = item.get("thumbnails")
        if thumbs:
            thumb_url = thumbs[-1].get("url")

        tracks.append({
            "title": item.get("title", "Unknown"),
            "artist": artist_name or "Unknown",
            "album": album_name,
            "youtube_id": item.get("videoId"),
            "image_url": thumb_url,
        })

    return name, image_url, tracks


def search_track(query: str) -> list[dict]:
    """Search YouTube Music for tracks matching the query.

    Returns a list of result dicts with: title, artist, album, youtube_id, image_url.
    """
    results = ytmusic.search(query, filter="songs", limit=10)

    tracks = []
    for item in results:
        artists = item.get("artists") or []
        artist_name = ", ".join(a.get("name", "") for a in artists if a.get("name"))

        album_name = None
        album = item.get("album")
        if album:
            album_name = album.get("name")

        thumb_url = None
        thumbs = item.get("thumbnails")
        if thumbs:
            thumb_url = thumbs[-1].get("url")

        tracks.append({
            "title": item.get("title", "Unknown"),
            "artist": artist_name or "Unknown",
            "album": album_name,
            "youtube_id": item.get("videoId"),
            "image_url": thumb_url,
        })

    return tracks