Rework Axis entity loader to have a better internal storage structure (#114114)

* Make one single subscribe containing all topics at once

* Update homeassistant/components/axis/hub/entity_loader.py

Co-authored-by: J. Nick Koston <nick@koston.org>

---------

Co-authored-by: J. Nick Koston <nick@koston.org>

homeassistant/components/axis/hub/entity_loader.py

@@ -5,7 +5,6 @@ Central point to load entities for the different platforms.
 
 from __future__ import annotations
 
-from functools import partial
 from typing import TYPE_CHECKING
 
 from axis.models.event import Event, EventOperation, EventTopic
@@ -23,17 +22,20 @@ class AxisEntityLoader:
     """Axis network device integration handling platforms for entity registration."""
 
     def __init__(self, hub: AxisHub) -> None:
-        """Initialize the UniFi entity loader."""
+        """Initialize the Axis entity loader."""
         self.hub = hub
 
         self.registered_events: set[tuple[str, EventTopic, str]] = set()
-        self.platforms: list[
+        self.topic_to_entity: dict[
+            EventTopic,
+            list[
                 tuple[
                     AddEntitiesCallback,
                     type[AxisEventEntity],
-                tuple[AxisEventDescription, ...],
+                    AxisEventDescription,
                 ]
-        ] = []
+            ],
+        ] = {}
 
     @callback
     def register_platform(
@@ -43,37 +45,39 @@ class AxisEntityLoader:
         descriptions: tuple[AxisEventDescription, ...],
     ) -> None:
         """Register Axis entity platforms."""
-        self.platforms.append((async_add_entities, entity_class, descriptions))
+        topics: tuple[EventTopic, ...]
+        for description in descriptions:
+            if isinstance(description.event_topic, EventTopic):
+                topics = (description.event_topic,)
+            else:
+                topics = description.event_topic
+            for topic in topics:
+                self.topic_to_entity.setdefault(topic, []).append(
+                    (async_add_entities, entity_class, description)
+                )
+
+    @callback
+    def _create_entities_from_event(self, event: Event) -> None:
+        """Create Axis entities from event."""
+        event_id = (event.topic, event.topic_base, event.id)
+        if event_id in self.registered_events:
+            # Device has restarted and all events are initialized anew
+            return
+        self.registered_events.add(event_id)
+        for (
+            async_add_entities,
+            entity_class,
+            description,
+        ) in self.topic_to_entity[event.topic_base]:
+            if not description.supported_fn(self.hub, event):
+                continue
+            async_add_entities([entity_class(self.hub, description, event)])
 
     @callback
     def initialize_platforms(self) -> None:
-        """Prepare event listeners and platforms."""
-
-        @callback
-        def load_entities(
-            platform_entity: type[AxisEventEntity],
-            descriptions: tuple[AxisEventDescription, ...],
-            async_add_entities: AddEntitiesCallback,
-        ) -> None:
-            """Set up listeners for events."""
-
-            @callback
-            def create_entity(description: AxisEventDescription, event: Event) -> None:
-                """Create Axis entity."""
-                event_id = (event.topic, event.topic_base, event.id)
-                if event_id in self.registered_events:
-                    # Device has restarted and all events are initiatlized anew
-                    return
-                self.registered_events.add(event_id)
-                if description.supported_fn(self.hub, event):
-                    async_add_entities([platform_entity(self.hub, description, event)])
-
-            for description in descriptions:
+        """Prepare event listener that can populate platform entities."""
         self.hub.api.event.subscribe(
-                    partial(create_entity, description),
-                    topic_filter=description.event_topic,
+            self._create_entities_from_event,
+            topic_filter=tuple(self.topic_to_entity.keys()),
             operation_filter=EventOperation.INITIALIZED,
         )
-
-        for async_add_entities, entity_class, descriptions in self.platforms:
-            load_entities(entity_class, descriptions, async_add_entities)