Mark camera unavailable when keepalive stream fails (#62294)

* Mark camera unavailable when keepalive stream fails

Add a listener in stream that notifies camera when the stream state has changed, and
use that to inform the camera `available` property. Update the property to be set
only from the main loop where it is read to reduce thread safety races.

Issue #54659

* Fix pylint import related errors

* Address lint naming errors

* Apply suggestions from code review

Co-authored-by: Paulus Schoutsen <paulus@home-assistant.io>

Co-authored-by: Paulus Schoutsen <paulus@home-assistant.io>

tests/components/camera/test_init.py

@@ -16,7 +16,11 @@ from homeassistant.components.camera.const import (
 from homeassistant.components.camera.prefs import CameraEntityPreferences
 from homeassistant.components.websocket_api.const import TYPE_RESULT
 from homeassistant.config import async_process_ha_core_config
-from homeassistant.const import ATTR_ENTITY_ID, EVENT_HOMEASSISTANT_START
+from homeassistant.const import (
+    ATTR_ENTITY_ID,
+    EVENT_HOMEASSISTANT_START,
+    STATE_UNAVAILABLE,
+)
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.setup import async_setup_component
 
@@ -633,3 +637,56 @@ async def test_websocket_web_rtc_offer_invalid_stream_type(
     assert response["type"] == TYPE_RESULT
     assert not response["success"]
     assert response["error"]["code"] == "web_rtc_offer_failed"
+
+
+async def test_state_streaming(hass, hass_ws_client, mock_camera):
+    """Camera state."""
+    demo_camera = hass.states.get("camera.demo_camera")
+    assert demo_camera is not None
+    assert demo_camera.state == camera.STATE_STREAMING
+
+
+async def test_stream_unavailable(hass, hass_ws_client, mock_camera, mock_stream):
+    """Camera state."""
+    await async_setup_component(hass, "camera", {})
+
+    with patch(
+        "homeassistant.components.camera.Stream.endpoint_url",
+        return_value="http://home.assistant/playlist.m3u8",
+    ), patch(
+        "homeassistant.components.demo.camera.DemoCamera.stream_source",
+        return_value="http://example.com",
+    ), patch(
+        "homeassistant.components.camera.Stream.set_update_callback",
+    ) as mock_update_callback:
+        # Request playlist through WebSocket. We just want to create the stream
+        # but don't care about the result.
+        client = await hass_ws_client(hass)
+        await client.send_json(
+            {"id": 10, "type": "camera/stream", "entity_id": "camera.demo_camera"}
+        )
+        await client.receive_json()
+        assert mock_update_callback.called
+
+    # Simluate the stream going unavailable
+    callback = mock_update_callback.call_args.args[0]
+    with patch(
+        "homeassistant.components.camera.Stream.available", new_callable=lambda: False
+    ):
+        callback()
+        await hass.async_block_till_done()
+
+    demo_camera = hass.states.get("camera.demo_camera")
+    assert demo_camera is not None
+    assert demo_camera.state == STATE_UNAVAILABLE
+
+    # Simulate stream becomes available
+    with patch(
+        "homeassistant.components.camera.Stream.available", new_callable=lambda: True
+    ):
+        callback()
+        await hass.async_block_till_done()
+
+    demo_camera = hass.states.get("camera.demo_camera")
+    assert demo_camera is not None
+    assert demo_camera.state == camera.STATE_STREAMING