from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from sqlalchemy.orm import Session

from app.database import get_db
from app.auth import decode_access_token
from app.models.user import User
from app.models.form import Form

security = HTTPBearer(auto_error=False)


async def get_current_user(
    credentials: HTTPAuthorizationCredentials | None = Depends(security),
    db: Session = Depends(get_db),
) -> User:
    if not credentials:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Not authenticated")
    payload = decode_access_token(credentials.credentials)
    if payload is None:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid or expired token")
    user = db.get(User, int(payload["sub"]))
    if not user:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="User not found")
    return user


def verify_form_owner(
    form_id: int,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> Form:
    form = db.get(Form, form_id)
    if not form:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Form not found")
    if form.user_id != user.id:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="You are not the owner of this form")
    return form


async def get_optional_user(
    credentials: HTTPAuthorizationCredentials | None = Depends(security),
    db: Session = Depends(get_db),
) -> User | None:
    if not credentials:
        return None
    payload = decode_access_token(credentials.credentials)
    if payload is None:
        return None
    user = db.get(User, int(payload["sub"]))
    return user