Binary Sensor for Remote UI & Fix timezone (#22076)

* Binary Sensor for Remote UI

* Fix lint

* Revert make hass public

* Add tests

homeassistant/components/cloud/binary_sensor.py

@@ -0,0 +1,73 @@
+"""Support for Home Assistant Cloud binary sensors."""
+from homeassistant.components.binary_sensor import BinarySensorDevice
+from homeassistant.core import callback
+from homeassistant.helpers.dispatcher import async_dispatcher_connect
+
+from .const import DISPATCHER_REMOTE_UPDATE, DOMAIN
+
+DEPENDENCIES = ['cloud']
+
+
+async def async_setup_platform(
+        hass, config, async_add_entities, discovery_info=None):
+    """Set up the cloud binary sensors."""
+    if discovery_info is None:
+        return
+    cloud = hass.data[DOMAIN]
+
+    async_add_entities([CloudRemoteBinary(cloud)])
+
+
+class CloudRemoteBinary(BinarySensorDevice):
+    """Representation of an Cloud Remote UI Connection binary sensor."""
+
+    def __init__(self, cloud):
+        """Initialize the binary sensor."""
+        self.cloud = cloud
+        self._unsub_dispatcher = None
+
+    @property
+    def name(self) -> str:
+        """Return the name of the binary sensor, if any."""
+        return "Remote UI"
+
+    @property
+    def unique_id(self) -> str:
+        """Return a unique ID."""
+        return "cloud-remote-ui-connectivity"
+
+    @property
+    def is_on(self) -> bool:
+        """Return true if the binary sensor is on."""
+        return self.cloud.remote.is_connected
+
+    @property
+    def device_class(self) -> str:
+        """Return the class of this device, from component DEVICE_CLASSES."""
+        return 'connectivity'
+
+    @property
+    def available(self) -> bool:
+        """Return True if entity is available."""
+        return self.cloud.remote.certificate is not None
+
+    @property
+    def should_poll(self) -> bool:
+        """Return True if entity has to be polled for state."""
+        return False
+
+    async def async_added_to_hass(self):
+        """Register update dispatcher."""
+        @callback
+        def async_state_update(data):
+            """Update callback."""
+            self.async_write_ha_state()
+
+        self._unsub_dispatcher = async_dispatcher_connect(
+            self.hass, DISPATCHER_REMOTE_UPDATE, async_state_update)
+
+    async def async_will_remove_from_hass(self):
+        """Register update dispatcher."""
+        if self._unsub_dispatcher is not None:
+            self._unsub_dispatcher()
+            self._unsub_dispatcher = None