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


SECRET_KEY = "llmbenchmark_tr" # your secret key
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="api/token")

def create_access_token(data: dict):
    to_encode = data.copy()
    expire = datetime.now() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

def get_current_user(token: str = Depends(oauth2_scheme)):
    credentials_exception = HTTPException(
        status_code=401,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        return username
    except JWTError:
        raise credentials_exception