from collections.abc import Generator

from typing import Annotated

import jwt

from fastapi import Depends, HTTPException, status

from fastapi.security import OAuth2PasswordBearer

from jwt.exceptions import InvalidTokenError

from pydantic import ValidationError

from sqlmodel import Session

from app.core import security

from app.core.config import settings

from app.core.db import engine

from app.models import TokenPayload, User

reusable_oauth2 = OAuth2PasswordBearer(

    tokenUrl=f"{settings.API_V1_STR}/login/access-token"

)

def get_db() -> Generator[Session, None, None]:

    with Session(engine) as session:

        yield session

SessionDep = Annotated[Session, Depends(get_db)]

TokenDep = Annotated[str, Depends(reusable_oauth2)]

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 (InvalidTokenError, ValidationError):

        raise HTTPException(

            status_code=status.HTTP_403_FORBIDDEN,

            detail="Could not validate credentials",

        )

    user = session.get(User, token_data.sub)

    if not user:

        raise HTTPException(status_code=404, detail="User not found")

    if not user.is_active:

        raise HTTPException(status_code=400, detail="Inactive user")

    return user

CurrentUser = Annotated[User, Depends(get_current_user)]

def get_current_active_superuser(current_user: CurrentUser) -> User:

    if not current_user.is_superuser:

        raise HTTPException(

            status_code=403, detail="The user doesn't have enough privileges"

        )

    return current_user