From dc84196202a4683881ddac9942fe1c9af6de3b5b Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 26 Aug 2020 07:52:19 -0500
Subject: [PATCH] Add the ability to reload statistics platforms from yaml
 (#39268)

---
 .../components/statistics/__init__.py         |  3 +
 homeassistant/components/statistics/sensor.py | 12 +++-
 .../components/statistics/services.yaml       |  2 +
 tests/components/statistics/test_sensor.py    | 59 ++++++++++++++++++-
 tests/fixtures/statistics/configuration.yaml  |  4 ++
 5 files changed, 75 insertions(+), 5 deletions(-)
 create mode 100644 homeassistant/components/statistics/services.yaml
 create mode 100644 tests/fixtures/statistics/configuration.yaml

diff --git a/homeassistant/components/statistics/__init__.py b/homeassistant/components/statistics/__init__.py
index 3f0f03b4909..ce5f959d731 100644
--- a/homeassistant/components/statistics/__init__.py
+++ b/homeassistant/components/statistics/__init__.py
@@ -1 +1,4 @@
 """The statistics component."""
+
+DOMAIN = "statistics"
+PLATFORMS = ["sensor"]
diff --git a/homeassistant/components/statistics/sensor.py b/homeassistant/components/statistics/sensor.py
index 945e5ff89d1..11cddc88c87 100644
--- a/homeassistant/components/statistics/sensor.py
+++ b/homeassistant/components/statistics/sensor.py
@@ -23,8 +23,11 @@ from homeassistant.helpers.event import (
     async_track_point_in_utc_time,
     async_track_state_change_event,
 )
+from homeassistant.helpers.reload import async_setup_reload_service
 from homeassistant.util import dt as dt_util
 
+from . import DOMAIN, PLATFORMS
+
 _LOGGER = logging.getLogger(__name__)
 
 ATTR_AVERAGE_CHANGE = "average_change"
@@ -66,6 +69,9 @@ PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
 
 async def async_setup_platform(hass, config, async_add_entities, discovery_info=None):
     """Set up the Statistics sensor."""
+
+    await async_setup_reload_service(hass, DOMAIN, PLATFORMS)
+
     entity_id = config.get(CONF_ENTITY_ID)
     name = config.get(CONF_NAME)
     sampling_size = config.get(CONF_SAMPLING_SIZE)
@@ -124,8 +130,10 @@ class StatisticsSensor(Entity):
             """Add listener and get recorded state."""
             _LOGGER.debug("Startup for %s", self.entity_id)
 
-            async_track_state_change_event(
-                self.hass, [self._entity_id], async_stats_sensor_state_listener
+            self.async_on_remove(
+                async_track_state_change_event(
+                    self.hass, [self._entity_id], async_stats_sensor_state_listener
+                )
             )
 
             if "recorder" in self.hass.config.components:
diff --git a/homeassistant/components/statistics/services.yaml b/homeassistant/components/statistics/services.yaml
new file mode 100644
index 00000000000..608e2991334
--- /dev/null
+++ b/homeassistant/components/statistics/services.yaml
@@ -0,0 +1,2 @@
+reload:
+  description: Reload all statistics entities.
diff --git a/tests/components/statistics/test_sensor.py b/tests/components/statistics/test_sensor.py
index 6d7f0963fa2..7a96ec4e2a4 100644
--- a/tests/components/statistics/test_sensor.py
+++ b/tests/components/statistics/test_sensor.py
@@ -1,14 +1,21 @@
 """The test for the statistics sensor platform."""
 from datetime import datetime, timedelta
+from os import path
 import statistics
 import unittest
 
 import pytest
 
+from homeassistant import config as hass_config
 from homeassistant.components import recorder
-from homeassistant.components.statistics.sensor import StatisticsSensor
-from homeassistant.const import ATTR_UNIT_OF_MEASUREMENT, STATE_UNKNOWN, TEMP_CELSIUS
-from homeassistant.setup import setup_component
+from homeassistant.components.statistics.sensor import DOMAIN, StatisticsSensor
+from homeassistant.const import (
+    ATTR_UNIT_OF_MEASUREMENT,
+    SERVICE_RELOAD,
+    STATE_UNKNOWN,
+    TEMP_CELSIUS,
+)
+from homeassistant.setup import async_setup_component, setup_component
 from homeassistant.util import dt as dt_util
 
 from tests.async_mock import patch
@@ -442,3 +449,49 @@ class TestStatisticsSensor(unittest.TestCase):
         assert mock_data["return_time"] == state.attributes.get("max_age") + timedelta(
             hours=1
         )
+
+
+async def test_reload(hass):
+    """Verify we can reload filter sensors."""
+    await hass.async_add_executor_job(
+        init_recorder_component, hass
+    )  # force in memory db
+
+    hass.states.async_set("sensor.test_monitored", 12345)
+    await async_setup_component(
+        hass,
+        "sensor",
+        {
+            "sensor": {
+                "platform": "statistics",
+                "name": "test",
+                "entity_id": "sensor.test_monitored",
+                "sampling_size": 100,
+            }
+        },
+    )
+    await hass.async_block_till_done()
+    await hass.async_start()
+    await hass.async_block_till_done()
+
+    assert len(hass.states.async_all()) == 2
+
+    assert hass.states.get("sensor.test")
+
+    yaml_path = path.join(
+        _get_fixtures_base_path(), "fixtures", "statistics/configuration.yaml",
+    )
+    with patch.object(hass_config, "YAML_CONFIG_FILE", yaml_path):
+        await hass.services.async_call(
+            DOMAIN, SERVICE_RELOAD, {}, blocking=True,
+        )
+        await hass.async_block_till_done()
+
+    assert len(hass.states.async_all()) == 2
+
+    assert hass.states.get("sensor.test") is None
+    assert hass.states.get("sensor.cputest")
+
+
+def _get_fixtures_base_path():
+    return path.dirname(path.dirname(path.dirname(__file__)))
diff --git a/tests/fixtures/statistics/configuration.yaml b/tests/fixtures/statistics/configuration.yaml
new file mode 100644
index 00000000000..a6ce34377a0
--- /dev/null
+++ b/tests/fixtures/statistics/configuration.yaml
@@ -0,0 +1,4 @@
+sensor:
+  - platform: statistics
+    entity_id: sensor.cpu
+    name: cputest