Class UnsubscribeEncoder

app/handler/unsubscribe_encoder.py:42–130

class UnsubscribeEncoder:
    @staticmethod
    def encode(
        action: UnsubscribeAction,
        data: Union[int, UnsubscribeOriginalData],
        force_web: bool = False,
    ) -> UnsubscribeLink:
        if config.UNSUBSCRIBER and not force_web:
            return UnsubscribeLink(UnsubscribeEncoder.encode_mailto(action, data), True)
        return UnsubscribeLink(UnsubscribeEncoder.encode_url(action, data), False)

    @classmethod
    def encode_subject(
        cls, action: UnsubscribeAction, data: Union[int, UnsubscribeOriginalData]
    ) -> str:
        if action != UnsubscribeAction.OriginalUnsubscribeMailto and not isinstance(
            data, int
        ):
            raise ValueError(f"Data has to be an int for an action of type {action}")
        if action == UnsubscribeAction.OriginalUnsubscribeMailto:
            if type(data) is not UnsubscribeOriginalData:
                raise ValueError(
                    f"Data has to be an UnsubscribeOriginalData for an action of type {action}"
                )
            # Initial 0 is the version number. If we need to add support for extra use-cases we can bump up this number
            data = (0, data.alias_id, data.recipient, data.subject)
        payload = (action.value, data)
        serialized_data = (
            base64.urlsafe_b64encode(json.dumps(payload).encode("utf-8"))
            .rstrip(b"=")
            .decode("utf-8")
        )
        signed_data = cls._get_signer().sign(serialized_data).decode("utf-8")
        encoded_request = f"{UNSUB_PREFIX}.{signed_data}"
        if len(encoded_request) > 512:
            LOG.w("Encoded request is longer than 512 chars")
        return encoded_request

    @staticmethod
    def encode_mailto(
        action: UnsubscribeAction, data: Union[int, UnsubscribeOriginalData]
    ) -> str:
        subject = UnsubscribeEncoder.encode_subject(action, data)
        return f"mailto:{config.UNSUBSCRIBER}?subject={subject}"

    @staticmethod
    def encode_url(
        action: UnsubscribeAction, data: Union[int, UnsubscribeOriginalData]
    ) -> str:
        if action == UnsubscribeAction.DisableAlias:
            return f"{config.URL}/dashboard/unsubscribe/{data}"
        if action == UnsubscribeAction.DisableContact:
            return f"{config.URL}/dashboard/block_contact/{data}"
        if action in (
            UnsubscribeAction.UnsubscribeNewsletter,
            UnsubscribeAction.OriginalUnsubscribeMailto,
        ):
            encoded = UnsubscribeEncoder.encode_subject(action, data)