from typing import Annotated, Generator

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

from app.config import settings
from app.core import security
from app.db import engine
from app.models.user import User
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)]