"""passbook oauth_client Authorization backend"""
from django.contrib.auth.backends import ModelBackend
from django.db.models import Q
from django.http import HttpRequest

from passbook.core.models import User
from passbook.sources.oauth.models import OAuthSource, UserOAuthSourceConnection


class AuthorizedServiceBackend(ModelBackend):
    "Authentication backend for users registered with remote OAuth provider."

    def authenticate(
        self, request: HttpRequest, source: OAuthSource, identifier: str
    ) -> User:
        "Fetch user for a given source by id."
        source_q = Q(source__name=source)
        if isinstance(source, OAuthSource):
            source_q = Q(source=source)
        access = UserOAuthSourceConnection.objects.filter(
            source_q, identifier=identifier
        ).select_related("user")[0]
        return access.user