import json

def extract(hf_token):
    """
    Extract token, user, redirect, and info from input hf_token.
    If hf_token is simple, it is the token itself.
    """
    info = {} # a copy of hf_token in json format
    try:
        info = json.loads(hf_token)
    except json.decoder.JSONDecodeError:
        return hf_token, None, None, None

    try:
        token = info['token']
    except KeyError:
        token = None

    try:
        user = info['user']
    except KeyError:
        user = None

    try:
        redirect = info['redirect']
    except KeyError:
        redirect = None

    return token, user, redirect, info