Entity registry (#11979)

* Entity#unique_id defaults to None

* Initial commit entity registry

* Clean up unique_id property

* Lint

* Add tests to entity component

* Lint

* Restore some unique ids

* Spelling

* Remove use of IP address for unique ID

* Add tests

* Add tests

* Fix tests

* Add some docs

* Add one more test

* Fix new test…

homeassistant/helpers/entity_component.py

@@ -8,10 +8,9 @@ from homeassistant.setup import async_prepare_setup_platform
 from homeassistant.const import (
     ATTR_ENTITY_ID, CONF_SCAN_INTERVAL, CONF_ENTITY_NAMESPACE,
     DEVICE_DEFAULT_NAME)
-from homeassistant.core import callback, valid_entity_id
+from homeassistant.core import callback, valid_entity_id, split_entity_id
 from homeassistant.exceptions import HomeAssistantError, PlatformNotReady
 from homeassistant.helpers import config_per_platform, discovery
-from homeassistant.helpers.entity import async_generate_entity_id
 from homeassistant.helpers.event import (
     async_track_time_interval, async_track_point_in_time)
 from homeassistant.helpers.service import extract_entity_ids
@@ -19,11 +18,13 @@ from homeassistant.util import slugify
 from homeassistant.util.async import (
     run_callback_threadsafe, run_coroutine_threadsafe)
 import homeassistant.util.dt as dt_util
+from .entity_registry import EntityRegistry
 
 DEFAULT_SCAN_INTERVAL = timedelta(seconds=15)
 SLOW_SETUP_WARNING = 10
 SLOW_SETUP_MAX_WAIT = 60
 PLATFORM_NOT_READY_RETRIES = 10
+DATA_REGISTRY = 'entity_registry'
 
 
 class EntityComponent(object):
@@ -357,12 +358,20 @@ class EntityPlatform(object):
         if not new_entities:
             return
 
+        hass = self.component.hass
         component_entities = set(entity.entity_id for entity
                                  in self.component.entities)
 
+        registry = hass.data.get(DATA_REGISTRY)
+
+        if registry is None:
+            registry = hass.data[DATA_REGISTRY] = EntityRegistry(hass)
+
+        yield from registry.async_ensure_loaded()
+
         tasks = [
             self._async_add_entity(entity, update_before_add,
-                                   component_entities)
+                                   component_entities, registry)
             for entity in new_entities]
 
         yield from asyncio.wait(tasks, loop=self.component.hass.loop)
@@ -378,15 +387,12 @@ class EntityPlatform(object):
         )
 
     @asyncio.coroutine
-    def _async_add_entity(self, entity, update_before_add, component_entities):
+    def _async_add_entity(self, entity, update_before_add, component_entities,
+                          registry):
         """Helper method to add an entity to the platform."""
         if entity is None:
             raise ValueError('Entity cannot be None')
 
-        # Do nothing if entity has already been added based on unique id.
-        if entity in self.component.entities:
-            return
-
         entity.hass = self.component.hass
         entity.platform = self
         entity.parallel_updates = self.parallel_updates
@@ -400,17 +406,39 @@ class EntityPlatform(object):
                     "%s: Error on device update!", self.platform)
                 return
 
-        # Write entity_id to entity
-        if getattr(entity, 'entity_id', None) is None:
-            object_id = entity.name or DEVICE_DEFAULT_NAME
+        suggested_object_id = None
+
+        # Get entity_id from unique ID registration
+        if entity.unique_id is not None:
+            if entity.entity_id is not None:
+                suggested_object_id = split_entity_id(entity.entity_id)[1]
+            else:
+                suggested_object_id = entity.name
+
+            entry = registry.async_get_or_create(
+                self.component.domain, self.platform, entity.unique_id,
+                suggested_object_id=suggested_object_id)
+            entity.entity_id = entry.entity_id
+
+        # We won't generate an entity ID if the platform has already set one
+        # We will however make sure that platform cannot pick a registered ID
+        elif (entity.entity_id is not None and
+              registry.async_is_registered(entity.entity_id)):
+            # If entity already registered, convert entity id to suggestion
+            suggested_object_id = split_entity_id(entity.entity_id)[1]
+            entity.entity_id = None
+
+        # Generate entity ID
+        if entity.entity_id is None:
+            suggested_object_id = \
+                suggested_object_id or entity.name or DEVICE_DEFAULT_NAME
 
             if self.entity_namespace is not None:
-                object_id = '{} {}'.format(self.entity_namespace,
-                                           object_id)
+                suggested_object_id = '{} {}'.format(self.entity_namespace,
+                                                     suggested_object_id)
 
-            entity.entity_id = async_generate_entity_id(
-                self.component.entity_id_format, object_id,
-                component_entities)
+            entity.entity_id = registry.async_generate_entity_id(
+                self.component.domain, suggested_object_id)
 
         # Make sure it is valid in case an entity set the value themselves
         if not valid_entity_id(entity.entity_id):