from datetime import datetime, timedelta

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

from app.config import settings

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

ALGORITHM = "HS256"


def create_access_token(subject: str) -> str:
    expire = datetime.utcnow() + timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
    return jwt.encode({"sub": subject, "exp": expire}, settings.SECRET_KEY, algorithm=ALGORITHM)


def get_current_user(token: str = Depends(oauth2_scheme)) -> str:
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED)
        return username
    except JWTError:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED)