from fastapi import Depends, HTTPException, Request, status
from jose import JWTError, jwt
from sqlalchemy.orm import Session

from app.core.config import settings
from app.db.session import get_db
from app.models.user import User


def get_optional_user(request: Request, db: Session = Depends(get_db)) -> User | None:
    token = request.cookies.get("access_token")
    if not token:
        return None
    try:
        payload = jwt.decode(token, settings.secret_key, algorithms=[settings.algorithm])
        user_id = int(payload.get("sub"))
    except (JWTError, TypeError, ValueError):
        return None
    return db.query(User).filter(User.id == user_id, User.is_active.is_(True)).first()


def get_current_user(request: Request, db: Session = Depends(get_db)) -> User:
    token = request.cookies.get("access_token")
    if not token:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Nicht angemeldet.")
    try:
        payload = jwt.decode(token, settings.secret_key, algorithms=[settings.algorithm])
        user_id = int(payload.get("sub"))
    except (JWTError, TypeError, ValueError) as exc:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Ungültiger Token.") from exc

    user = db.query(User).filter(User.id == user_id, User.is_active.is_(True)).first()
    if not user:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Benutzer nicht gefunden.")
    return user


def get_admin_user(current_user: User = Depends(get_current_user)) -> User:
    if current_user.role != "admin" and not current_user.is_admin:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Admin-Rechte erforderlich.")
    return current_user


def require_editor_or_admin(current_user: User = Depends(get_current_user)) -> User:
    if current_user.role not in {"admin", "editor"}:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Editor- oder Admin-Rechte erforderlich.")
    return current_user


def require_reader_or_higher(current_user: User = Depends(get_current_user)) -> User:
    if current_user.role not in {"admin", "editor", "reader"}:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Admin-Rechte erforderlich.")
    return current_user