From 5fdcbbe0e1111475712da44e727de7c433a83030 Mon Sep 17 00:00:00 2001
From: Allen Porter <allen@thebends.org>
Date: Sun, 5 Dec 2021 09:45:40 -0800
Subject: [PATCH] Fetch media for events for rendering in the nest media player
 (#61056)

---
 homeassistant/components/nest/__init__.py | 8 ++++++++
 tests/components/nest/common.py           | 6 ++++++
 2 files changed, 14 insertions(+)

diff --git a/homeassistant/components/nest/__init__.py b/homeassistant/components/nest/__init__.py
index af3757d31da..fb39188710c 100644
--- a/homeassistant/components/nest/__init__.py
+++ b/homeassistant/components/nest/__init__.py
@@ -86,6 +86,11 @@ PLATFORMS = ["sensor", "camera", "climate"]
 WEB_AUTH_DOMAIN = DOMAIN
 INSTALLED_AUTH_DOMAIN = f"{DOMAIN}.installed"
 
+# Fetch media for events with an in memory cache. The largest media items
+# are mp4 clips at ~90kb each, so this totals a few MB per camera.
+# Note: Media for events can only be published within 30 seconds of the event
+EVENT_MEDIA_CACHE_SIZE = 64
+
 
 class WebAuth(config_entry_oauth2_flow.LocalOAuth2Implementation):
     """OAuth implementation using OAuth for web applications."""
@@ -206,6 +211,9 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     subscriber = await api.new_subscriber(hass, entry)
     if not subscriber:
         return False
+    # Keep media for last N events in memory
+    subscriber.cache_policy.event_cache_size = EVENT_MEDIA_CACHE_SIZE
+    subscriber.cache_policy.fetch = True
 
     callback = SignalUpdateCallback(hass)
     subscriber.set_update_callback(callback.async_handle_event)
diff --git a/tests/components/nest/common.py b/tests/components/nest/common.py
index eb44b19d540..a0ba813ab28 100644
--- a/tests/components/nest/common.py
+++ b/tests/components/nest/common.py
@@ -6,6 +6,7 @@ from unittest.mock import patch
 
 from google_nest_sdm.device_manager import DeviceManager
 from google_nest_sdm.event import EventMessage
+from google_nest_sdm.event_media import CachePolicy
 from google_nest_sdm.google_nest_subscriber import GoogleNestSubscriber
 
 from homeassistant.components.nest import DOMAIN
@@ -98,6 +99,11 @@ class FakeSubscriber(GoogleNestSubscriber):
         """Return the fake device manager."""
         return self._device_manager
 
+    @property
+    def cache_policy(self) -> CachePolicy:
+        """Return the cache policy."""
+        return self._device_manager.cache_policy
+
     def stop_async(self):
         """No-op to stop the subscriber."""
         return None