Authentication

class AuthenticationBackend:
    """Base class for implementing the Authentication into SQLAdmin.
    You need to inherit this class and override the methods:
    `login`, `logout` and `authenticate`.
    """

    def __init__(self, secret_key: str, **session_kwargs: Any) -> None:
        from starlette.middleware.sessions import SessionMiddleware

        self.middlewares = [
            Middleware(SessionMiddleware, secret_key=secret_key, **session_kwargs),
        ]

    async def login(self, request: Request) -> Response | bool:
        """Implement login logic here.
        You can access the login form data `await request.form()`
        and validate the credentials.
        """
        raise NotImplementedError()

    async def logout(self, request: Request) -> Response | bool:
        """Implement logout logic here.
        This will usually clear the session with `request.session.clear()`.

        If a `Response` or `RedirectResponse` is returned,
        that response is returned to the user,
        otherwise the user will be redirected to the index page.
        """
        raise NotImplementedError()

    async def authenticate(self, request: Request) -> Response | bool:
        """Implement authenticate logic here.
        This method will be called for each incoming request
        to validate the authentication.

        If a `Response` or `RedirectResponse` is returned,
        that response is returned to the user,
        otherwise a True/False is expected.
        """
        raise NotImplementedError()

    async def get_user_id(self, request: Request) -> Any:
        """Return an identifier for the authenticated user, or `None`.

        Called once per request after `authenticate` succeeds. The result is
        stored on the request and read back by
        [`get_current_user_id`][sqladmin.authentication.get_current_user_id],
        so everything that needs to know *who* is acting -- the audit backend
        and the authorization backend among them -- shares one answer instead
        of each re-deriving it.

        The default reads ``user_id`` from the session, which suits the
        session-based login flow in the docs. Override it for anything else.
        """

        if "session" in request.scope:
            return request.session.get("user_id")
        return None