"""
Last.fm integration using pylast.
"""

import pylast
from django.conf import settings


def get_network() -> pylast.LastFMNetwork:
    """Return a base LastFMNetwork (no session key attached)."""
    return pylast.LastFMNetwork(
        api_key=settings.LASTFM_API_KEY,
        api_secret=settings.LASTFM_API_SECRET,
    )


def get_auth_url(callback_url: str) -> tuple[str, str]:
    """
    Start the Last.fm web auth flow.

    Returns (auth_url, token). The caller should redirect the user to auth_url
    and store the token in the session for use in the callback.
    """
    network = get_network()
    sg = pylast.SessionKeyGenerator(network)
    token = sg.get_web_auth_token()
    url = sg.get_web_auth_url(token)
    return url, token


def get_session_key(token: str) -> str:
    """
    Exchange an authorized token for a permanent session key.

    Must be called after the user has visited the auth URL and clicked Allow.
    """
    network = get_network()
    sg = pylast.SessionKeyGenerator(network)
    return sg.get_web_auth_session_key(token)


def get_username(session_key: str) -> str:
    """Return the Last.fm username for the given session key."""
    network = get_network()
    network.session_key = session_key
    user = network.get_authenticated_user()
    return user.name


def scrobble(session_key: str, artist: str, title: str, timestamp: int) -> None:
    """
    Scrobble a track to Last.fm.

    timestamp should be a Unix epoch integer (seconds since 1970-01-01 UTC).
    """
    network = get_network()
    network.session_key = session_key
    network.scrobble(artist=artist, title=title, timestamp=timestamp)


def parse_track(raw: str) -> tuple[str, str]:
    """
    Parse a raw 'Artist - Title' string into (artist, title).

    Falls back to ('', raw) when no ' - ' separator is found.
    """
    if ' - ' in raw:
        parts = raw.split(' - ', 1)
        return parts[0].strip(), parts[1].strip()
    return '', raw.strip()