from typing import Annotated

from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from sqlmodel import Session, select

from app.core.security import decode_access_token
from app.db import SessionDep
from app.models.participant import Participant
from app.models.route import Route
from app.models.user import User

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="auth/login")


def get_current_user(session: SessionDep, token: Annotated[str, Depends(oauth2_scheme)]) -> User:
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    payload = decode_access_token(token)
    if payload is None or payload.get("sub") is None:
        raise credentials_exception
    user = session.get(User, int(payload["sub"]))
    if user is None or not user.is_active:
        raise credentials_exception
    return user


CurrentUser = Annotated[User, Depends(get_current_user)]


def get_current_active_superuser(
    current_user: CurrentUser,
    token: Annotated[str, Depends(oauth2_scheme)],
) -> User:
    if not current_user.is_superadmin:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Not enough privileges")
    payload = decode_access_token(token)
    if not payload or not payload.get("elevated"):
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="This action requires an elevated session — call POST /auth/elevate first",
        )
    return current_user


CurrentSuperuser = Annotated[User, Depends(get_current_active_superuser)]


def get_route_in_organization(session: Session, route_id: int, organization_id: int) -> Route:
    route = session.get(Route, route_id)
    if route is None or route.organization_id != organization_id:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Route not found")
    return route


def get_participant_in_organization(session: Session, participant_id: int, organization_id: int) -> Participant:
    participant = session.exec(
        select(Participant)
        .join(Route)
        .where(Participant.id == participant_id, Route.organization_id == organization_id)
    ).first()
    if participant is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Participant not found")
    return participant