Adjust backup agent platform (#132944)

* Adjust backup agent platform

* Adjust according to discussion

* Clean up the local agent dict too

* Add test

* Update kitchen_sink

* Apply suggestions from code review

Co-authored-by: Martin Hjelmare <marhje52@gmail.com>

* Adjust tests

* Clean up

* Fix kitchen sink reload

---------

Co-authored-by: Martin Hjelmare <marhje52@gmail.com>

homeassistant/components/backup/agent.py

@@ -7,7 +7,9 @@ from collections.abc import AsyncIterator, Callable, Coroutine
 from pathlib import Path
 from typing import Any, Protocol
 
-from homeassistant.core import HomeAssistant
+from propcache import cached_property
+
+from homeassistant.core import HomeAssistant, callback
 from homeassistant.exceptions import HomeAssistantError
 
 from .models import AgentBackup
@@ -26,8 +28,14 @@ class BackupAgentUnreachableError(BackupAgentError):
 class BackupAgent(abc.ABC):
     """Backup agent interface."""
 
+    domain: str
     name: str
 
+    @cached_property
+    def agent_id(self) -> str:
+        """Return the agent_id."""
+        return f"{self.domain}.{self.name}"
+
     @abc.abstractmethod
     async def async_download_backup(
         self,
@@ -98,3 +106,16 @@ class BackupAgentPlatformProtocol(Protocol):
         **kwargs: Any,
     ) -> list[BackupAgent]:
         """Return a list of backup agents."""
+
+    @callback
+    def async_register_backup_agents_listener(
+        self,
+        hass: HomeAssistant,
+        *,
+        listener: Callable[[], None],
+        **kwargs: Any,
+    ) -> Callable[[], None]:
+        """Register a listener to be called when agents are added or removed.
+
+        :return: A function to unregister the listener.
+        """

homeassistant/components/backup/backup.py

@@ -12,7 +12,7 @@ from homeassistant.core import HomeAssistant
 from homeassistant.helpers.hassio import is_hassio
 
 from .agent import BackupAgent, LocalBackupAgent
-from .const import LOGGER
+from .const import DOMAIN, LOGGER
 from .models import AgentBackup
 from .util import read_backup
 
@@ -30,6 +30,7 @@ async def async_get_backup_agents(
 class CoreLocalBackupAgent(LocalBackupAgent):
     """Local backup agent for Core and Container installations."""
 
+    domain = DOMAIN
     name = "local"
 
     def __init__(self, hass: HomeAssistant) -> None:

homeassistant/components/backup/manager.py

@@ -243,6 +243,7 @@ class BackupManager:
         """Initialize the backup manager."""
         self.hass = hass
         self.platforms: dict[str, BackupPlatformProtocol] = {}
+        self.backup_agent_platforms: dict[str, BackupAgentPlatformProtocol] = {}
         self.backup_agents: dict[str, BackupAgent] = {}
         self.local_backup_agents: dict[str, LocalBackupAgent] = {}
 
@@ -291,22 +292,48 @@ class BackupManager:
 
         self.platforms[integration_domain] = platform
 
-    async def _async_add_platform_agents(
+    @callback
+    def _async_add_backup_agent_platform(
         self,
         integration_domain: str,
         platform: BackupAgentPlatformProtocol,
     ) -> None:
-        """Add a platform to the backup manager."""
+        """Add backup agent platform to the backup manager."""
         if not hasattr(platform, "async_get_backup_agents"):
             return
 
-        agents = await platform.async_get_backup_agents(self.hass)
-        self.backup_agents.update(
-            {f"{integration_domain}.{agent.name}": agent for agent in agents}
+        self.backup_agent_platforms[integration_domain] = platform
+
+        @callback
+        def listener() -> None:
+            LOGGER.debug("Loading backup agents for %s", integration_domain)
+            self.hass.async_create_task(
+                self._async_reload_backup_agents(integration_domain)
             )
+
+        if hasattr(platform, "async_register_backup_agents_listener"):
+            platform.async_register_backup_agents_listener(self.hass, listener=listener)
+
+        listener()
+
+    async def _async_reload_backup_agents(self, domain: str) -> None:
+        """Add backup agent platform to the backup manager."""
+        platform = self.backup_agent_platforms[domain]
+
+        # Remove all agents for the domain
+        for agent_id in list(self.backup_agents):
+            if self.backup_agents[agent_id].domain == domain:
+                del self.backup_agents[agent_id]
+        for agent_id in list(self.local_backup_agents):
+            if self.local_backup_agents[agent_id].domain == domain:
+                del self.local_backup_agents[agent_id]
+
+        # Add new agents
+        agents = await platform.async_get_backup_agents(self.hass)
+        self.backup_agents.update({agent.agent_id: agent for agent in agents})
         self.local_backup_agents.update(
             {
-                f"{integration_domain}.{agent.name}": agent
+                agent.agent_id: agent
                 for agent in agents
                 if isinstance(agent, LocalBackupAgent)
             }
@@ -320,7 +347,7 @@ class BackupManager:
     ) -> None:
         """Add a backup platform manager."""
         self._add_platform_pre_post_handler(integration_domain, platform)
-        await self._async_add_platform_agents(integration_domain, platform)
+        self._async_add_backup_agent_platform(integration_domain, platform)
         LOGGER.debug("Backup platform %s loaded", integration_domain)
         LOGGER.debug("%s platforms loaded in total", len(self.platforms))
         LOGGER.debug("%s agents loaded in total", len(self.backup_agents))

homeassistant/components/cloud/backup.py

@@ -38,7 +38,11 @@ async def async_get_backup_agents(
     **kwargs: Any,
 ) -> list[BackupAgent]:
     """Return the cloud backup agent."""
-    return [CloudBackupAgent(hass=hass, cloud=hass.data[DATA_CLOUD])]
+    cloud = hass.data[DATA_CLOUD]
+    if not cloud.is_logged_in:
+        return []
+
+    return [CloudBackupAgent(hass=hass, cloud=cloud)]
 
 
 class ChunkAsyncStreamIterator:
@@ -69,6 +73,7 @@ class ChunkAsyncStreamIterator:
 class CloudBackupAgent(BackupAgent):
     """Cloud backup agent."""
 
+    domain = DOMAIN
     name = DOMAIN
 
     def __init__(self, hass: HomeAssistant, cloud: Cloud[CloudClient]) -> None:

homeassistant/components/hassio/backup.py

@@ -79,6 +79,8 @@ def _backup_details_to_agent_backup(
 class SupervisorBackupAgent(BackupAgent):
     """Backup agent for supervised installations."""
 
+    domain = DOMAIN
+
     def __init__(self, hass: HomeAssistant, name: str, location: str | None) -> None:
         """Initialize the backup agent."""
         super().__init__()

homeassistant/components/kitchen_sink/__init__.py

@@ -26,8 +26,7 @@ from homeassistant.helpers.issue_registry import IssueSeverity, async_create_iss
 from homeassistant.helpers.typing import ConfigType
 import homeassistant.util.dt as dt_util
 
-DOMAIN = "kitchen_sink"
-
+from .const import DATA_BACKUP_AGENT_LISTENERS, DOMAIN
 
 COMPONENTS_WITH_DEMO_PLATFORM = [
     Platform.BUTTON,
@@ -88,9 +87,27 @@ async def async_setup_entry(hass: HomeAssistant, config_entry: ConfigEntry) -> b
     # Start a reauth flow
     config_entry.async_start_reauth(hass)
 
+    # Notify backup listeners
+    hass.async_create_task(_notify_backup_listeners(hass), eager_start=False)
+
     return True
 
 
+async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
+    """Unload config entry."""
+    # Notify backup listeners
+    hass.async_create_task(_notify_backup_listeners(hass), eager_start=False)
+
+    return await hass.config_entries.async_unload_platforms(
+        entry, COMPONENTS_WITH_DEMO_PLATFORM
+    )
+
+
+async def _notify_backup_listeners(hass: HomeAssistant) -> None:
+    for listener in hass.data.get(DATA_BACKUP_AGENT_LISTENERS, []):
+        listener()
+
+
 def _create_issues(hass: HomeAssistant) -> None:
     """Create some issue registry issues."""
     async_create_issue(

homeassistant/components/kitchen_sink/backup.py

@@ -8,7 +8,9 @@ import logging
 from typing import Any
 
 from homeassistant.components.backup import AddonInfo, AgentBackup, BackupAgent, Folder
-from homeassistant.core import HomeAssistant
+from homeassistant.core import HomeAssistant, callback
+
+from . import DATA_BACKUP_AGENT_LISTENERS, DOMAIN
 
 LOGGER = logging.getLogger(__name__)
 
@@ -17,12 +19,35 @@ async def async_get_backup_agents(
     hass: HomeAssistant,
 ) -> list[BackupAgent]:
     """Register the backup agents."""
+    if not hass.config_entries.async_loaded_entries(DOMAIN):
+        LOGGER.info("No config entry found or entry is not loaded")
+        return []
     return [KitchenSinkBackupAgent("syncer")]
 
 
+@callback
+def async_register_backup_agents_listener(
+    hass: HomeAssistant,
+    *,
+    listener: Callable[[], None],
+    **kwargs: Any,
+) -> Callable[[], None]:
+    """Register a listener to be called when agents are added or removed."""
+    hass.data.setdefault(DATA_BACKUP_AGENT_LISTENERS, []).append(listener)
+
+    @callback
+    def remove_listener() -> None:
+        """Remove the listener."""
+        hass.data[DATA_BACKUP_AGENT_LISTENERS].remove(listener)
+
+    return remove_listener
+
+
 class KitchenSinkBackupAgent(BackupAgent):
     """Kitchen sink backup agent."""
 
+    domain = DOMAIN
+
     def __init__(self, name: str) -> None:
         """Initialize the kitchen sink backup sync agent."""
         super().__init__()

homeassistant/components/kitchen_sink/const.py

@@ -0,0 +1,12 @@
+"""Constants for the Kitchen Sink integration."""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+
+from homeassistant.util.hass_dict import HassKey
+
+DOMAIN = "kitchen_sink"
+DATA_BACKUP_AGENT_LISTENERS: HassKey[list[Callable[[], None]]] = HassKey(
+    f"{DOMAIN}.backup_agent_listeners"
+)

tests/components/backup/common.py

@@ -57,6 +57,8 @@ TEST_DOMAIN = "test"
 class BackupAgentTest(BackupAgent):
     """Test backup agent."""
 
+    domain = "test"
+
     def __init__(self, name: str, backups: list[AgentBackup] | None = None) -> None:
         """Initialize the backup agent."""
         self.name = name

tests/components/backup/test_manager.py

@@ -6,6 +6,7 @@ import asyncio
 from collections.abc import Generator
 from io import StringIO
 import json
+from pathlib import Path
 from typing import Any
 from unittest.mock import ANY, AsyncMock, MagicMock, Mock, call, mock_open, patch
 
@@ -18,6 +19,7 @@ from homeassistant.components.backup import (
     BackupManager,
     BackupPlatformProtocol,
     Folder,
+    LocalBackupAgent,
     backup as local_backup_platform,
 )
 from homeassistant.components.backup.const import DATA_MANAGER
@@ -534,21 +536,86 @@ async def test_loading_platforms(
 
     assert not manager.platforms
 
+    get_agents_mock = AsyncMock(return_value=[])
+
     await _setup_backup_platform(
         hass,
         platform=Mock(
             async_pre_backup=AsyncMock(),
             async_post_backup=AsyncMock(),
-            async_get_backup_agents=AsyncMock(),
+            async_get_backup_agents=get_agents_mock,
         ),
     )
     await manager.load_platforms()
     await hass.async_block_till_done()
 
     assert len(manager.platforms) == 1
-
     assert "Loaded 1 platforms" in caplog.text
 
+    get_agents_mock.assert_called_once_with(hass)
+
+
+class LocalBackupAgentTest(BackupAgentTest, LocalBackupAgent):
+    """Local backup agent."""
+
+    def get_backup_path(self, backup_id: str) -> Path:
+        """Return the local path to a backup."""
+        return "test.tar"
+
+
+@pytest.mark.parametrize(
+    ("agent_class", "num_local_agents"),
+    [(LocalBackupAgentTest, 2), (BackupAgentTest, 1)],
+)
+async def test_loading_platform_with_listener(
+    hass: HomeAssistant,
+    hass_ws_client: WebSocketGenerator,
+    agent_class: type[BackupAgentTest],
+    num_local_agents: int,
+) -> None:
+    """Test loading a backup agent platform which can be listened to."""
+    ws_client = await hass_ws_client(hass)
+    assert await async_setup_component(hass, DOMAIN, {})
+    manager = hass.data[DATA_MANAGER]
+
+    get_agents_mock = AsyncMock(return_value=[agent_class("remote1", backups=[])])
+    register_listener_mock = Mock()
+
+    await _setup_backup_platform(
+        hass,
+        domain="test",
+        platform=Mock(
+            async_get_backup_agents=get_agents_mock,
+            async_register_backup_agents_listener=register_listener_mock,
+        ),
+    )
+    await hass.async_block_till_done()
+
+    await ws_client.send_json_auto_id({"type": "backup/agents/info"})
+    resp = await ws_client.receive_json()
+    assert resp["result"]["agents"] == [
+        {"agent_id": "backup.local"},
+        {"agent_id": "test.remote1"},
+    ]
+    assert len(manager.local_backup_agents) == num_local_agents
+
+    get_agents_mock.assert_called_once_with(hass)
+    register_listener_mock.assert_called_once_with(hass, listener=ANY)
+
+    get_agents_mock.reset_mock()
+    get_agents_mock.return_value = [agent_class("remote2", backups=[])]
+    listener = register_listener_mock.call_args[1]["listener"]
+    listener()
+
+    get_agents_mock.assert_called_once_with(hass)
+    await ws_client.send_json_auto_id({"type": "backup/agents/info"})
+    resp = await ws_client.receive_json()
+    assert resp["result"]["agents"] == [
+        {"agent_id": "backup.local"},
+        {"agent_id": "test.remote2"},
+    ]
+    assert len(manager.local_backup_agents) == num_local_agents
+
 
 @pytest.mark.parametrize(
     "platform_mock",

tests/components/cloud/test_backup.py

@@ -26,7 +26,10 @@ from tests.typing import ClientSessionGenerator, MagicMock, WebSocketGenerator
 
 @pytest.fixture(autouse=True)
 async def setup_integration(
-    hass: HomeAssistant, aioclient_mock: AiohttpClientMocker, cloud: MagicMock
+    hass: HomeAssistant,
+    aioclient_mock: AiohttpClientMocker,
+    cloud: MagicMock,
+    cloud_logged_in: None,
 ) -> AsyncGenerator[None]:
     """Set up cloud integration."""
     with patch("homeassistant.components.backup.is_hassio", return_value=False):

tests/components/kitchen_sink/test_backup.py

@@ -57,6 +57,27 @@ async def test_agents_info(
         "agents": [{"agent_id": "backup.local"}, {"agent_id": "kitchen_sink.syncer"}],
     }
 
+    config_entry = hass.config_entries.async_entries(DOMAIN)[0]
+    await hass.config_entries.async_unload(config_entry.entry_id)
+    await hass.async_block_till_done()
+
+    await client.send_json_auto_id({"type": "backup/agents/info"})
+    response = await client.receive_json()
+
+    assert response["success"]
+    assert response["result"] == {"agents": [{"agent_id": "backup.local"}]}
+
+    await hass.config_entries.async_setup(config_entry.entry_id)
+    await hass.async_block_till_done()
+
+    await client.send_json_auto_id({"type": "backup/agents/info"})
+    response = await client.receive_json()
+
+    assert response["success"]
+    assert response["result"] == {
+        "agents": [{"agent_id": "backup.local"}, {"agent_id": "kitchen_sink.syncer"}],
+    }
+
 
 async def test_agents_list_backups(
     hass: HomeAssistant,