Add support for Google Home device tracking (#18190)

* Add support for Google Home device tracking.

* Use dict[key] for options.

* Delete googlehome.py.save

* Change stylling of name, and attr mac_address to btle_mac_address, removed unesssesarry attributes copying.

homeassistant/components/device_tracker/googlehome.py

@@ -0,0 +1,92 @@
+"""
+Support for Google Home bluetooth tacker.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/device_tracker.googlehome/
+"""
+import logging
+
+import voluptuous as vol
+
+import homeassistant.helpers.config_validation as cv
+from homeassistant.helpers.aiohttp_client import async_get_clientsession
+from homeassistant.components.device_tracker import (
+    DOMAIN, PLATFORM_SCHEMA, DeviceScanner)
+from homeassistant.const import CONF_HOST
+
+REQUIREMENTS = ['ghlocalapi==0.0.1']
+
+_LOGGER = logging.getLogger(__name__)
+
+CONF_RSSI_THRESHOLD = 'rssi_threshold'
+
+PLATFORM_SCHEMA = vol.All(
+    PLATFORM_SCHEMA.extend({
+        vol.Required(CONF_HOST): cv.string,
+        vol.Optional(CONF_RSSI_THRESHOLD, default=-70): vol.Coerce(int),
+    }))
+
+
+async def async_get_scanner(hass, config):
+    """Validate the configuration and return an Google Home scanner."""
+    scanner = GoogleHomeDeviceScanner(hass, config[DOMAIN])
+    await scanner.async_connect()
+    return scanner if scanner.success_init else None
+
+
+class GoogleHomeDeviceScanner(DeviceScanner):
+    """This class queries a Google Home unit."""
+
+    def __init__(self, hass, config):
+        """Initialize the scanner."""
+        from ghlocalapi.device_info import DeviceInfo
+        from ghlocalapi.bluetooth import BluetoothScan
+
+        self.last_results = {}
+
+        self.success_init = False
+        self._host = config[CONF_HOST]
+        self.rssi_threshold = config[CONF_RSSI_THRESHOLD]
+
+        session = async_get_clientsession(hass)
+        self.deviceinfo = DeviceInfo(hass.loop, session, self._host)
+        self.scanner = BluetoothScan(hass.loop, session, self._host)
+
+    async def async_connect(self):
+        """Initialize connection to Google Home."""
+        await self.deviceinfo.get_device_info()
+        data = self.deviceinfo.device_info
+        self.success_init = data is not None
+
+    async def async_scan_devices(self):
+        """Scan for new devices and return a list with found device IDs."""
+        await self.async_update_info()
+        return list(self.last_results.keys())
+
+    async def async_get_device_name(self, device):
+        """Return the name of the given device or None if we don't know."""
+        if device not in self.last_results:
+            return None
+        return '{}_{}'.format(self._host,
+                              self.last_results[device]['btle_mac_address'])
+
+    async def get_extra_attributes(self, device):
+        """Return the extra attributes of the device."""
+        return self.last_results[device]
+
+    async def async_update_info(self):
+        """Ensure the information from Google Home is up to date."""
+        _LOGGER.debug('Checking Devices...')
+        await self.scanner.scan_for_devices()
+        await self.scanner.get_scan_result()
+        ghname = self.deviceinfo.device_info['name']
+        devices = {}
+        for device in self.scanner.devices:
+            if device['rssi'] > self.rssi_threshold:
+                uuid = '{}_{}'.format(self._host, device['mac_address'])
+                devices[uuid] = {}
+                devices[uuid]['rssi'] = device['rssi']
+                devices[uuid]['btle_mac_address'] = device['mac_address']
+                devices[uuid]['ghname'] = ghname
+                devices[uuid]['source_type'] = 'bluetooth'
+        self.last_results = devices