import hashlib

from ..utils import handle_http_errors
from .base import BaseAuth


class LastFmAuth(BaseAuth):
    """
    Last.Fm authentication backend. Requires two settings:
        SOCIAL_AUTH_LASTFM_KEY
        SOCIAL_AUTH_LASTFM_SECRET

    Don't forget to set the Last.fm callback to something sensible like
        http://your.site/lastfm/complete
    """

    name = "lastfm"
    AUTH_URL = "http://www.last.fm/api/auth/?api_key={api_key}"
    EXTRA_DATA = [("key", "session_key")]

    def auth_url(self):
        return self.AUTH_URL.format(api_key=self.setting("KEY"))

    @handle_http_errors
    def auth_complete(self, *args, **kwargs):
        """Completes login process, must return user instance"""
        key, secret = self.get_key_and_secret()
        token = self.data["token"]

        signature = hashlib.md5(
            "".join(
                ("api_key", key, "methodauth.getSession", "token", token, secret)
            ).encode()
        ).hexdigest()

        response = self.get_json(
            "http://ws.audioscrobbler.com/2.0/",
            data={
                "method": "auth.getSession",
                "api_key": key,
                "token": token,
                "api_sig": signature,
                "format": "json",
            },
            method="POST",
        )

        kwargs.update({"response": response["session"], "backend": self})
        return self.strategy.authenticate(*args, **kwargs)

    def get_user_id(self, details, response):
        """Return a unique ID for the current user, by default from server
        response."""
        return response.get("name")

    def get_user_details(self, response):
        fullname, first_name, last_name = self.get_user_names(response["name"])
        return {
            "username": response["name"],
            "email": "",
            "fullname": fullname,
            "first_name": first_name,
            "last_name": last_name,
        }