from fastapi import Depends, HTTPException, Request, status
from fastapi.responses import RedirectResponse
from sqlalchemy.orm import Session

from app import config, security
from app.database import get_db
from app.models import User


class LoginRequired(HTTPException):
    """Raised when there is no valid session; handled by redirecting to /admin/login."""

    def __init__(self):
        super().__init__(status_code=status.HTTP_303_SEE_OTHER)


def login_redirect_handler(request: Request, exc: LoginRequired):
    return RedirectResponse("/admin/login", status_code=303)


def current_user(request: Request, db: Session = Depends(get_db)) -> User:
    token = request.cookies.get(config.SESSION_COOKIE)
    user_id = security.read_session_token(token) if token else None
    if user_id is None:
        raise LoginRequired()
    user = db.get(User, user_id)
    if user is None or not user.is_active:
        raise LoginRequired()
    return user