core/homeassistant/components/skybeacon/sensor.py

"""Support for Skybeacon temperature/humidity Bluetooth LE sensors."""
import logging
import threading
from uuid import UUID

import voluptuous as vol

from homeassistant.components.sensor import PLATFORM_SCHEMA
from homeassistant.const import (
    CONF_MAC,
    CONF_NAME,
    EVENT_HOMEASSISTANT_STOP,
    STATE_UNKNOWN,
    TEMP_CELSIUS,
)
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.entity import Entity

_LOGGER = logging.getLogger(__name__)

ATTR_DEVICE = "device"
ATTR_MODEL = "model"

BLE_TEMP_HANDLE = 0x24
BLE_TEMP_UUID = "0000ff92-0000-1000-8000-00805f9b34fb"

CONNECT_LOCK = threading.Lock()
CONNECT_TIMEOUT = 30

DEFAULT_NAME = "Skybeacon"

SKIP_HANDLE_LOOKUP = True

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
    {
        vol.Required(CONF_MAC): cv.string,
        vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
    }
)


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up the Skybeacon sensor."""
    name = config.get(CONF_NAME)
    mac = config.get(CONF_MAC)
    _LOGGER.debug("Setting up...")

    mon = Monitor(hass, mac, name)
    add_entities([SkybeaconTemp(name, mon)])
    add_entities([SkybeaconHumid(name, mon)])

    def monitor_stop(_service_or_event):
        """Stop the monitor thread."""
        _LOGGER.info("Stopping monitor for %s", name)
        mon.terminate()

    hass.bus.listen_once(EVENT_HOMEASSISTANT_STOP, monitor_stop)
    mon.start()


class SkybeaconHumid(Entity):
    """Representation of a Skybeacon humidity sensor."""

    def __init__(self, name, mon):
        """Initialize a sensor."""
        self.mon = mon
        self._name = name

    @property
    def name(self):
        """Return the name of the sensor."""
        return self._name

    @property
    def state(self):
        """Return the state of the device."""
        return self.mon.data["humid"]

    @property
    def unit_of_measurement(self):
        """Return the unit the value is expressed in."""
        return "%"

    @property
    def device_state_attributes(self):
        """Return the state attributes of the sensor."""
        return {ATTR_DEVICE: "SKYBEACON", ATTR_MODEL: 1}


class SkybeaconTemp(Entity):
    """Representation of a Skybeacon temperature sensor."""

    def __init__(self, name, mon):
        """Initialize a sensor."""
        self.mon = mon
        self._name = name

    @property
    def name(self):
        """Return the name of the sensor."""
        return self._name

    @property
    def state(self):
        """Return the state of the device."""
        return self.mon.data["temp"]

    @property
    def unit_of_measurement(self):
        """Return the unit the value is expressed in."""
        return TEMP_CELSIUS

    @property
    def device_state_attributes(self):
        """Return the state attributes of the sensor."""
        return {ATTR_DEVICE: "SKYBEACON", ATTR_MODEL: 1}


class Monitor(threading.Thread):
    """Connection handling."""

    def __init__(self, hass, mac, name):
        """Construct interface object."""
        threading.Thread.__init__(self)
        self.daemon = False
        self.hass = hass
        self.mac = mac
        self.name = name
        self.data = {"temp": STATE_UNKNOWN, "humid": STATE_UNKNOWN}
        self.keep_going = True
        self.event = threading.Event()

    def run(self):
        """Thread that keeps connection alive."""
        # pylint: disable=import-error
        import pygatt
        from pygatt.backends import Characteristic
        from pygatt.exceptions import BLEError, NotConnectedError, NotificationTimeout

        cached_char = Characteristic(BLE_TEMP_UUID, BLE_TEMP_HANDLE)
        adapter = pygatt.backends.GATTToolBackend()
        while True:
            try:
                _LOGGER.debug("Connecting to %s", self.name)
                # We need concurrent connect, so lets not reset the device
                adapter.start(reset_on_start=False)
                # Seems only one connection can be initiated at a time
                with CONNECT_LOCK:
                    device = adapter.connect(
                        self.mac, CONNECT_TIMEOUT, pygatt.BLEAddressType.random
                    )
                if SKIP_HANDLE_LOOKUP:
                    # HACK: inject handle mapping collected offline
                    # pylint: disable=protected-access
                    device._characteristics[UUID(BLE_TEMP_UUID)] = cached_char
                # Magic: writing this makes device happy
                device.char_write_handle(0x1B, bytearray([255]), False)
                device.subscribe(BLE_TEMP_UUID, self._update)
                _LOGGER.info("Subscribed to %s", self.name)
                while self.keep_going:
                    # protect against stale connections, just read temperature
                    device.char_read(BLE_TEMP_UUID, timeout=CONNECT_TIMEOUT)
                    self.event.wait(60)
                break
            except (BLEError, NotConnectedError, NotificationTimeout) as ex:
                _LOGGER.error("Exception: %s ", str(ex))
            finally:
                adapter.stop()

    def _update(self, handle, value):
        """Notification callback from pygatt."""
        _LOGGER.debug(
            "%s: %15s temperature = %-2d.%-2d, humidity = %3d",
            handle,
            self.name,
            value[0],
            value[2],
            value[1],
        )
        self.data["temp"] = float(("%d.%d" % (value[0], value[2])))
        self.data["humid"] = value[1]

    def terminate(self):
        """Signal runner to stop and join thread."""
        self.keep_going = False
        self.event.set()
        self.join()