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

from app.core.config import settings
from app.core.database import get_session
from app.core.security import decode_access_token
from app.models.user import User

reusable_oauth2 = OAuth2PasswordBearer(
    tokenUrl=f"/auth/login"
)

def get_current_user(
    session: Annotated[Session, Depends(get_session)],
    token: Annotated[str, Depends(reusable_oauth2)]
) -> User:
    """
    FastAPI dependency to get the current authenticated user.
    """
    payload = decode_access_token(token)
    user_id = payload.get("sub")
    if not user_id:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Could not validate credentials",
            headers={"WWW-Authenticate": "Bearer"},
        )
    
    user = session.get(User, user_id)
    if not user:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="User not found",
        )
    
    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Inactive user",
        )
        
    return user