from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jose import JWTError
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.security import decode_access_token
from app.database import get_db
from app.models.user import User

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


async def get_current_user(
    token: str = Depends(oauth2_scheme),
    db: AsyncSession = Depends(get_db),
) -> User:
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        user_id = decode_access_token(token)
    except JWTError:
        raise credentials_exception

    result = await db.execute(select(User).where(User.id == user_id))
    user = result.scalar_one_or_none()
    if not user or not user.is_active:
        raise credentials_exception
    return user


async def get_current_admin(
    current_user: User = Depends(get_current_user),
) -> User:
    if not current_user.is_superuser:
        # Return 404 instead of 403 — reveals neither the existence of the
        # endpoint nor that the caller lacks permission.
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Not found",
        )
    return current_user