from typing import Generator
from sqlmodel import Session
from app.db import engine

from typing import Generator, Annotated
from sqlmodel import Session, select
from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jose import jwt, JWTError
from pydantic import ValidationError

from app.db import engine
from app.models.user import User
from app.core import security
from app.config import settings
from app.schemas.token import TokenPayload

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/v1/login/access-token")

def get_session() -> Generator[Session, None, None]:
    with Session(engine) as session:
        yield session

SessionDep = Annotated[Session, Depends(get_session)]
TokenDep = Annotated[str, Depends(oauth2_scheme)]

def get_current_user(session: SessionDep, token: TokenDep) -> User:
    try:
        payload = jwt.decode(
            token, settings.SECRET_KEY, algorithms=[security.ALGORITHM]
        )
        token_data = TokenPayload(**payload)
    except (JWTError, ValidationError):
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Could not validate credentials",
        )
    user = session.get(User, int(token_data.sub))
    if not user:
        raise HTTPException(status_code=404, detail="User not found")
    return user

CurrentUser = Annotated[User, Depends(get_current_user)]