switchbot-mqtt/switchbot_mqtt/_actors/base.py

# switchbot-mqtt - MQTT client controlling SwitchBot button & curtain automators,
# compatible with home-assistant.io's MQTT Switch & Cover platform
#
# Copyright (C) 2020 Fabian Peter Hammerle <fabian@hammerle.me>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

# > Even with __all__ set appropriately, internal interfaces (packages,
# > modules, classes, functions, attributes or other names) should still be
# > prefixed with a single leading underscore. An interface is also considered
# > internal if any containing namespace (package, module or class) is
# > considered internal.
# https://peps.python.org/pep-0008/#public-and-internal-interfaces

from __future__ import annotations  # PEP563 (default in python>=3.10)

import abc
import logging
import typing

import aiomqtt
import bleak
import bleak.backends.device
import switchbot
from switchbot_mqtt._utils import (
    _join_mqtt_topic_levels,
    _mac_address_valid,
    _MQTTTopicLevel,
    _MQTTTopicPlaceholder,
    _parse_mqtt_topic,
)

_LOGGER = logging.getLogger(__name__)


class _MQTTControlledActor(abc.ABC):
    MQTT_COMMAND_TOPIC_LEVELS: typing.Tuple[_MQTTTopicLevel, ...] = NotImplemented
    _MQTT_UPDATE_DEVICE_INFO_TOPIC_LEVELS: typing.Tuple[
        _MQTTTopicLevel, ...
    ] = NotImplemented
    MQTT_STATE_TOPIC_LEVELS: typing.Tuple[_MQTTTopicLevel, ...] = NotImplemented
    _MQTT_BATTERY_PERCENTAGE_TOPIC_LEVELS: typing.Tuple[
        _MQTTTopicLevel, ...
    ] = NotImplemented

    @classmethod
    def get_mqtt_update_device_info_topic(cls, *, prefix: str, mac_address: str) -> str:
        return _join_mqtt_topic_levels(
            topic_prefix=prefix,
            topic_levels=cls._MQTT_UPDATE_DEVICE_INFO_TOPIC_LEVELS,
            mac_address=mac_address,
        )

    @classmethod
    def get_mqtt_battery_percentage_topic(cls, *, prefix: str, mac_address: str) -> str:
        return _join_mqtt_topic_levels(
            topic_prefix=prefix,
            topic_levels=cls._MQTT_BATTERY_PERCENTAGE_TOPIC_LEVELS,
            mac_address=mac_address,
        )

    @abc.abstractmethod
    def __init__(
        self,
        *,
        device: bleak.backends.device.BLEDevice,
        retry_count: int,
        password: typing.Optional[str],
    ) -> None:
        # alternative: pySwitchbot >=0.10.0 provides SwitchbotDevice.get_mac()
        self._mac_address = device.address
        self._basic_device_info: typing.Optional[typing.Dict[str, typing.Any]] = None

    @abc.abstractmethod
    def _get_device(self) -> switchbot.SwitchbotDevice:
        raise NotImplementedError()

    async def _report_battery_level(
        self, mqtt_client: aiomqtt.Client, mqtt_topic_prefix: str
    ) -> None:
        assert self._basic_device_info is not None
        # > battery: Percentage of battery that is left.
        # https://www.home-assistant.io/integrations/sensor/#device-class
        await self._mqtt_publish(
            topic_prefix=mqtt_topic_prefix,
            topic_levels=self._MQTT_BATTERY_PERCENTAGE_TOPIC_LEVELS,
            payload=str(self._basic_device_info["battery"]).encode(),
            mqtt_client=mqtt_client,
        )

    async def _update_and_report_device_info(
        self, mqtt_client: aiomqtt.Client, mqtt_topic_prefix: str
    ) -> None:
        self._basic_device_info = await self._get_device().get_basic_info()
        if self._basic_device_info is None:
            _LOGGER.error(
                "failed to retrieve basic device info from %s", self._mac_address
            )
        else:
            await self._report_battery_level(
                mqtt_client=mqtt_client, mqtt_topic_prefix=mqtt_topic_prefix
            )

    @classmethod
    async def _init_from_topic(
        cls,
        *,
        topic: aiomqtt.Topic,
        mqtt_topic_prefix: str,
        expected_topic_levels: typing.Collection[_MQTTTopicLevel],
        retry_count: int,
        device_passwords: typing.Dict[str, str],
    ) -> typing.Optional[_MQTTControlledActor]:
        try:
            mac_address = _parse_mqtt_topic(
                topic=topic.value,
                expected_prefix=mqtt_topic_prefix,
                expected_levels=expected_topic_levels,
            )[_MQTTTopicPlaceholder.MAC_ADDRESS]
        except ValueError as exc:
            _LOGGER.warning(str(exc), exc_info=False)
            return None
        if not _mac_address_valid(mac_address):
            _LOGGER.warning("invalid mac address %s", mac_address)
            return None
        # SwitchbotBaseDevice.__init__ expects BLEDevice
        device = await bleak.BleakScanner.find_device_by_address(mac_address)
        if device is None:
            _LOGGER.error(
                "failed to find bluetooth low energy device with mac address %s",
                mac_address,
            )
            return None
        return cls(
            device=device,
            retry_count=retry_count,
            password=device_passwords.get(mac_address, None),
        )

    @classmethod
    async def _mqtt_update_device_info_callback(
        # pylint: disable=duplicate-code; other callbacks with same params
        cls,
        *,
        mqtt_client: aiomqtt.Client,
        message: aiomqtt.Message,
        mqtt_topic_prefix: str,
        retry_count: int,
        device_passwords: typing.Dict[str, str],
        fetch_device_info: bool,
    ) -> None:
        # pylint: disable=unused-argument; callback
        # https://github.com/eclipse/paho.mqtt.python/blob/v1.5.0/src/paho/mqtt/client.py#L469
        _LOGGER.debug("received topic=%s payload=%r", message.topic, message.payload)
        if message.retain:
            _LOGGER.info("ignoring retained message")
            return
        actor = await cls._init_from_topic(
            topic=message.topic,
            mqtt_topic_prefix=mqtt_topic_prefix,
            expected_topic_levels=cls._MQTT_UPDATE_DEVICE_INFO_TOPIC_LEVELS,
            retry_count=retry_count,
            device_passwords=device_passwords,
        )
        if actor:
            # pylint: disable=protected-access; own instance
            await actor._update_and_report_device_info(
                mqtt_client=mqtt_client, mqtt_topic_prefix=mqtt_topic_prefix
            )

    @abc.abstractmethod
    async def execute_command(  # pylint: disable=duplicate-code; implementations
        self,
        *,
        mqtt_message_payload: bytes,
        mqtt_client: aiomqtt.Client,
        update_device_info: bool,
        mqtt_topic_prefix: str,
    ) -> None:
        raise NotImplementedError()

    @classmethod
    async def _mqtt_command_callback(
        # pylint: disable=duplicate-code; other callbacks with same params
        cls,
        *,
        mqtt_client: aiomqtt.Client,
        message: aiomqtt.Message,
        mqtt_topic_prefix: str,
        retry_count: int,
        device_passwords: typing.Dict[str, str],
        fetch_device_info: bool,
    ) -> None:
        # pylint: disable=unused-argument; callback
        # https://github.com/eclipse/paho.mqtt.python/blob/v1.5.0/src/paho/mqtt/client.py#L469
        _LOGGER.debug("received topic=%s payload=%r", message.topic, message.payload)
        if message.retain:
            _LOGGER.info("ignoring retained message")
            return
        actor = await cls._init_from_topic(
            topic=message.topic,
            mqtt_topic_prefix=mqtt_topic_prefix,
            expected_topic_levels=cls.MQTT_COMMAND_TOPIC_LEVELS,
            retry_count=retry_count,
            device_passwords=device_passwords,
        )
        if actor:
            assert isinstance(message.payload, bytes), message.payload
            await actor.execute_command(
                mqtt_message_payload=message.payload,
                mqtt_client=mqtt_client,
                update_device_info=fetch_device_info,
                mqtt_topic_prefix=mqtt_topic_prefix,
            )

    @classmethod
    def _get_mqtt_message_callbacks(
        cls,
        *,
        enable_device_info_update_topic: bool,
    ) -> typing.Dict[typing.Tuple[_MQTTTopicLevel, ...], typing.Callable]:
        # returning dict because `paho.mqtt.client.Client.message_callback_add` overwrites
        # callbacks with same topic pattern
        # https://github.com/eclipse/paho.mqtt.python/blob/v1.6.1/src/paho/mqtt/client.py#L2304
        # https://github.com/eclipse/paho.mqtt.python/blob/v1.6.1/src/paho/mqtt/matcher.py#L19
        callbacks = {cls.MQTT_COMMAND_TOPIC_LEVELS: cls._mqtt_command_callback}
        if enable_device_info_update_topic:
            callbacks[
                cls._MQTT_UPDATE_DEVICE_INFO_TOPIC_LEVELS
            ] = cls._mqtt_update_device_info_callback
        return callbacks

    @classmethod
    async def mqtt_subscribe(
        cls,
        *,
        mqtt_client: aiomqtt.Client,
        mqtt_topic_prefix: str,
        fetch_device_info: bool,
    ) -> typing.AsyncIterator[typing.Tuple[str, typing.Callable]]:
        for topic_levels, callback in cls._get_mqtt_message_callbacks(
            enable_device_info_update_topic=fetch_device_info
        ).items():
            topic = _join_mqtt_topic_levels(
                topic_prefix=mqtt_topic_prefix,
                topic_levels=topic_levels,
                mac_address="+",
            )
            _LOGGER.info("subscribing to MQTT topic %r", topic)
            await mqtt_client.subscribe(topic)
            yield (topic, callback)

    async def _mqtt_publish(
        self,
        *,
        topic_prefix: str,
        topic_levels: typing.Iterable[_MQTTTopicLevel],
        payload: bytes,
        mqtt_client: aiomqtt.Client,
    ) -> None:
        topic = _join_mqtt_topic_levels(
            topic_prefix=topic_prefix,
            topic_levels=topic_levels,
            mac_address=self._mac_address,
        )
        # https://pypi.org/project/paho-mqtt/#publishing
        _LOGGER.debug("publishing topic=%s payload=%r", topic, payload)
        try:
            await mqtt_client.publish(topic=topic, payload=payload, retain=True)
        except aiomqtt.MqttCodeError as exc:
            _LOGGER.error(
                "Failed to publish MQTT message on topic %s: aiomqtt.MqttCodeError %s",
                topic,
                exc,
            )

    async def report_state(
        self,
        state: bytes,
        mqtt_client: aiomqtt.Client,
        mqtt_topic_prefix: str,
    ) -> None:
        await self._mqtt_publish(
            topic_prefix=mqtt_topic_prefix,
            topic_levels=self.MQTT_STATE_TOPIC_LEVELS,
            payload=state,
            mqtt_client=mqtt_client,
        )