Homekit controller reconnect (#17060)

* Add threaded call_later helper

* Reconnect to device when connection fails

* Consolidate connection logs and warn on first

homeassistant/components/homekit_controller/__init__.py

@@ -13,6 +13,7 @@ import uuid
 from homeassistant.components.discovery import SERVICE_HOMEKIT
 from homeassistant.helpers import discovery
 from homeassistant.helpers.entity import Entity
+from homeassistant.helpers.event import call_later
 
 REQUIREMENTS = ['homekit==0.10']
 
@@ -37,6 +38,13 @@ KNOWN_DEVICES = "{}-devices".format(DOMAIN)
 
 _LOGGER = logging.getLogger(__name__)
 
+REQUEST_TIMEOUT = 5  # seconds
+RETRY_INTERVAL = 60  # seconds
+
+
+class HomeKitConnectionError(ConnectionError):
+    """Raised when unable to connect to target device."""
+
 
 def homekit_http_send(self, message_body=None, encode_chunked=False):
     r"""Send the currently buffered request and clear the buffer.
@@ -89,6 +97,9 @@ class HKDevice():
         self.config_num = config_num
         self.config = config
         self.configurator = hass.components.configurator
+        self.conn = None
+        self.securecon = None
+        self._connection_warning_logged = False
 
         data_dir = os.path.join(hass.config.path(), HOMEKIT_DIR)
         if not os.path.isdir(data_dir):
@@ -101,23 +112,35 @@ class HKDevice():
         # pylint: disable=protected-access
         http.client.HTTPConnection._send_output = homekit_http_send
 
-        self.conn = http.client.HTTPConnection(self.host, port=self.port)
         if self.pairing_data is not None:
             self.accessory_setup()
         else:
             self.configure()
 
+    def connect(self):
+        """Open the connection to the HomeKit device."""
+        # pylint: disable=import-error
+        import homekit
+
+        self.conn = http.client.HTTPConnection(
+            self.host, port=self.port, timeout=REQUEST_TIMEOUT)
+        if self.pairing_data is not None:
+            controllerkey, accessorykey = \
+                homekit.get_session_keys(self.conn, self.pairing_data)
+            self.securecon = homekit.SecureHttp(
+                self.conn.sock, accessorykey, controllerkey)
+
     def accessory_setup(self):
         """Handle setup of a HomeKit accessory."""
         # pylint: disable=import-error
         import homekit
-        self.controllerkey, self.accessorykey = \
-            homekit.get_session_keys(self.conn, self.pairing_data)
-        self.securecon = homekit.SecureHttp(self.conn.sock,
-                                            self.accessorykey,
-                                            self.controllerkey)
-        response = self.securecon.get('/accessories')
-        data = json.loads(response.read().decode())
+
+        try:
+            data = self.get_json('/accessories')
+        except HomeKitConnectionError:
+            call_later(
+                self.hass, RETRY_INTERVAL, lambda _: self.accessory_setup())
+            return
         for accessory in data['accessories']:
             serial = get_serial(accessory)
             if serial in self.hass.data[KNOWN_ACCESSORIES]:
@@ -135,6 +158,31 @@ class HKDevice():
                     discovery.load_platform(self.hass, component, DOMAIN,
                                             service_info, self.config)
 
+    def get_json(self, target):
+        """Get JSON data from the device."""
+        try:
+            if self.conn is None:
+                self.connect()
+            response = self.securecon.get(target)
+            data = json.loads(response.read().decode())
+
+            # After a successful connection, clear the warning logged status
+            self._connection_warning_logged = False
+
+            return data
+        except (ConnectionError, OSError, json.JSONDecodeError) as ex:
+            # Mark connection as failed
+            if not self._connection_warning_logged:
+                _LOGGER.warning("Failed to connect to homekit device",
+                                exc_info=ex)
+                self._connection_warning_logged = True
+            else:
+                _LOGGER.debug("Failed to connect to homekit device",
+                              exc_info=ex)
+            self.conn = None
+            self.securecon = None
+            raise HomeKitConnectionError() from ex
+
     def device_config_callback(self, callback_data):
         """Handle initial pairing."""
         # pylint: disable=import-error
@@ -142,6 +190,7 @@ class HKDevice():
         pairing_id = str(uuid.uuid4())
         code = callback_data.get('code').strip()
         try:
+            self.connect()
             self.pairing_data = homekit.perform_pair_setup(self.conn, code,
                                                            pairing_id)
         except homekit.exception.UnavailableError:
@@ -192,7 +241,7 @@ class HomeKitEntity(Entity):
     def __init__(self, accessory, devinfo):
         """Initialise a generic HomeKit device."""
         self._name = accessory.model
-        self._securecon = accessory.securecon
+        self._accessory = accessory
         self._aid = devinfo['aid']
         self._iid = devinfo['iid']
         self._address = "homekit-{}-{}".format(devinfo['serial'], self._iid)
@@ -201,8 +250,10 @@ class HomeKitEntity(Entity):
 
     def update(self):
         """Obtain a HomeKit device's state."""
-        response = self._securecon.get('/accessories')
-        data = json.loads(response.read().decode())
+        try:
+            data = self._accessory.get_json('/accessories')
+        except HomeKitConnectionError:
+            return
         for accessory in data['accessories']:
             if accessory['aid'] != self._aid:
                 continue
@@ -222,6 +273,11 @@ class HomeKitEntity(Entity):
         """Return the name of the device if any."""
         return self._name
 
+    @property
+    def available(self) -> bool:
+        """Return True if entity is available."""
+        return self._accessory.conn is not None
+
     def update_characteristics(self, characteristics):
         """Synchronise a HomeKit device state with Home Assistant."""
         raise NotImplementedError
@@ -229,7 +285,7 @@ class HomeKitEntity(Entity):
     def put_characteristics(self, characteristics):
         """Control a HomeKit device state from Home Assistant."""
         body = json.dumps({'characteristics': characteristics})
-        self._securecon.put('/characteristics', body)
+        self._accessory.securecon.put('/characteristics', body)
 
 
 def setup(hass, config):