from __future__ import annotations
import functools
from quart import session, redirect, url_for, abort, g
from roundtable.models.users import UserRole

_ROLE_ORDER = [UserRole.viewer, UserRole.operator, UserRole.admin]


def require_role(minimum_role: UserRole):
    """Decorator: requires authenticated user with at least minimum_role.
    Also allows access for validated share-token requests (viewer level only).
    """
    def decorator(f):
        @functools.wraps(f)
        async def wrapper(*args, **kwargs):
            # Share-token requests bypass session auth for viewer-level endpoints
            if getattr(g, "share_viewer", False) and minimum_role == UserRole.viewer:
                return await f(*args, **kwargs)
            user_id = session.get("user_id")
            if not user_id:
                return redirect(url_for("auth.login"))
            user_role = UserRole(session.get("user_role", "viewer"))
            if _ROLE_ORDER.index(user_role) < _ROLE_ORDER.index(minimum_role):
                abort(403)
            return await f(*args, **kwargs)
        return wrapper
    return decorator


def login_user(user) -> None:
    """Write user identity into the session."""
    session["user_id"] = user.id
    session["user_role"] = user.role.value
    session["username"] = user.username


def logout_user() -> None:
    session.clear()


def current_user_id() -> str | None:
    return session.get("user_id")