from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jose import JWTError, jwt
from sqlalchemy.orm import Session

from app.core.config import get_settings
from app.core.database import SessionLocal
from app.crud import user as user_crud
from app.models.user import User

settings = get_settings()

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/v1/auth/login")


def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


def get_current_user(
    db: Session = Depends(get_db),
    token: str = Depends(oauth2_scheme),
) -> User:
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=["HS256"])
        subject = payload.get("sub")
        if subject is None:
            raise credentials_exception
    except JWTError:
        raise credentials_exception

    user = user_crud.get_by_email(db, subject)
    if not user:
        raise credentials_exception
    return user