From 84d7c3f8bd44263c5b2d2ac3375f867824def831 Mon Sep 17 00:00:00 2001
From: Jon Connell <python@figsandfudge.com>
Date: Sun, 25 Jun 2023 10:51:50 +0100
Subject: [PATCH] Fix timezome history comparison

---
 .../kingspan_watchman_sensit/api.py           | 23 ++++++++++++-------
 tests/conftest.py                             |  6 ++---
 tests/test_sensor.py                          |  2 +-
 3 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/custom_components/kingspan_watchman_sensit/api.py b/custom_components/kingspan_watchman_sensit/api.py
index 42d0d31..753f9ce 100644
--- a/custom_components/kingspan_watchman_sensit/api.py
+++ b/custom_components/kingspan_watchman_sensit/api.py
@@ -75,10 +75,7 @@ async def _get_tank_data(self):
             return self.data
 
     def usage_rate(self, tank_data: TankData):
-        time_delta = datetime.today() - timedelta(days=USAGE_WINDOW)
-        time_delta = time_delta.replace(tzinfo=LOCAL_TZINFO)
-        history = tank_data.history
-        history = [x for x in history if x["reading_date"] >= time_delta]
+        history = filter_history(tank_data.history)
         if len(history) == 0:
             return 0
 
@@ -100,10 +97,7 @@ def usage_rate(self, tank_data: TankData):
             return 0
 
     def forecast_empty(self, tank_data: TankData):
-        time_delta = datetime.today() - timedelta(days=USAGE_WINDOW)
-        time_delta = time_delta.replace(tzinfo=LOCAL_TZINFO)
-        history = tank_data.history
-        history = [x for x in history if x["reading_date"] >= time_delta]
+        history = filter_history(tank_data.history)
         if len(history) == 0:
             return 0
 
@@ -114,3 +108,16 @@ def forecast_empty(self, tank_data: TankData):
         else:
             current_level = int(history[-1]["level_litres"])
             return int(current_level / abs(rate))
+
+
+def filter_history(history: list[dict]) -> list[dict]:
+    """Filter tank history to a smaller recent window of days"""
+    time_delta = datetime.today() - timedelta(days=USAGE_WINDOW)
+    time_delta = time_delta.replace(tzinfo=LOCAL_TZINFO)
+    # API returns naive datetime rather than with timezones
+    history = [
+        dict(x, reading_date=x["reading_date"].replace(tzinfo=LOCAL_TZINFO))
+        for x in history
+    ]
+    history = [x for x in history if x["reading_date"] >= time_delta]
+    return history
diff --git a/tests/conftest.py b/tests/conftest.py
index 6878ef6..1712f5b 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -16,8 +16,6 @@
     HistoryType,
 )
 
-LOCAL_TZINFO = datetime.now(timezone.utc).astimezone().tzinfo
-
 pytest_plugins = "pytest_homeassistant_custom_component"
 
 
@@ -80,7 +78,7 @@ def error_sensor_client_fixture():
 def decreasing_history(start_date: datetime) -> list:
     history = []
     start_date = start_date.replace(
-        hour=0, minute=30, second=0, microsecond=0, tzinfo=LOCAL_TZINFO
+        hour=0, minute=30, second=0, microsecond=0
     ) - timedelta(days=30)
 
     for day in range(1, 20):
@@ -156,7 +154,7 @@ async def last_read(self) -> str:
         if len(history) > 0:
             return history[-1]["reading_date"]
         else:
-            return datetime.now().replace(tzinfo=LOCAL_TZINFO)
+            return datetime.now()
 
     @async_property
     async def history(self) -> str:
diff --git a/tests/test_sensor.py b/tests/test_sensor.py
index beba301..734a4e0 100644
--- a/tests/test_sensor.py
+++ b/tests/test_sensor.py
@@ -38,7 +38,7 @@ async def test_sensor(hass, mock_sensor_client):
     state = hass.states.get("sensor.last_reading_date")
     assert state
     test_date = datetime.now().replace(hour=0, minute=30, second=0, microsecond=0)
-    # Timestamps from HA are in UTC
+    # Timestamps from HA are in UTC``
     test_date = test_date.astimezone(timezone.utc)
     assert state.state == test_date.isoformat()
     assert state.attributes.get(ATTR_ICON) == "mdi:clock-outline"