thing.py

class ClientTokenRefresh(object):
    """
    ClientTokenRefresh provides functionality to refresh Identity and
    Integration access tokens for integration API clients.

    Not all integrations will need this as some use non-expiring tokens.
    """
    @classmethod
    def check_auth(cls, model, force_refresh=False, refresh_strategy=None, **kwargs):
        """
        Check auth provides a generic yet configurable way to refresh oauth2
        style authentication tokens.

        Depending on the model passed different strategies will be used to
        refresh the token.

        - Identity
          When an Identity model is provided, the token will be refreshed using
          the identity providers `refresh_identity` method. Updating and
          returning the identity model.

        - Integration
          When an Integration model is provided, the token will be refreshed
          using the identity provider associated to the intergrations
          `refresh_oauth_data` method the token, however the access token
          will be persisted on the intergration model.

        If the token should not be refreshed using the identity providers `refresh_oauth_data`
        capabilities, a custom refresh strategy can be provided.

        By default this wiill check the ``exipred_at`` key, which is expected
        to be a unix timestamp, with the current time. If you wish to force
        access token refreshing (or require a different strategy for comparing
        expires_at) you may pass ``force_refresh=True``.
        """
        if isinstance(model, Identity):
            oauth_data = model.data
            strategy = cls.strategy_identity_refresh
        elif isinstance(model, Integration):
            oauth_data = model.metadata
            strategy = cls.strategy_integration_oauth_refresh

        # Use a default strategy for the provided model if no custom strategy
        # is provided
        if refresh_strategy is None:
            refresh_strategy = strategy

        expires_at = oauth_data.get('expires_at')

        # If we have no expires_at time then we should immedaitely try and refresh
        # the token. This is likely due to integrations such as slack that
        # previosuly did *not* have expiring tokens, or integrations that
        # previously set a 'expires' isntead of 'expires_at' key.
        if expires_at is None:
            force_refresh = True

        if force_refresh or int(expires_at) <= int(time()):
            return refresh_strategy(model, **kwargs)