import secrets
from datetime import datetime, timedelta

import pytz


class Nonce:
    def __init__(self, value: str = None, expiration: datetime = None):
        self.value = value if value is not None else secrets.token_hex(12)
        self.expiration = expiration if expiration is not None else (datetime.now(tz=pytz.UTC) + timedelta(hours=12))