Adopt Home Assistant's time zone for the API household clock (task 6351b36d) (#275)

Co-authored-by: Joshua <joshua@cnjmail.com>
Co-committed-by: Joshua <joshua@cnjmail.com>

custom_components/nestquest/core/const.py

@@ -113,18 +113,25 @@ CONF_END_OF_DAY_REPORT_ENABLED = "end_of_day_report_enabled"
 CONF_CELEBRATION_ENABLED = "celebration_enabled"
 DEFAULT_AUTOMATION_ENABLED = True
 # The household's IANA time zone (e.g. ``America/New_York``) the API
-# service reads its clock in.  The empty string keeps the historical
-# behaviour — the API host's own local time — so an existing install is
-# unchanged until the owner sets it.  The integration itself always uses
-# Home Assistant's configured ``time_zone`` and ignores this field.
+# service reads its clock in.  The empty string is the API host's own
+# local time.  While the admin has not chosen a zone
+# (``timezone_configured`` is ``False``) the API adopts the zone the
+# integration reports from Home Assistant's configured ``time_zone``
+# (:data:`PANEL_TIMEZONE_HEADER`), so the default is the household's
+# zone without any manual setup.  The integration itself always uses
+# Home Assistant's ``time_zone`` and ignores this field.
 CONF_TIMEZONE = "timezone"
 DEFAULT_TIMEZONE = ""
 # Whether the admin has made an explicit ``timezone`` choice.  ``False``
-# (a fresh install) lets the admin UI auto-set the browser's zone once;
-# ``True`` pins the stored value — including an explicitly-chosen empty
-# ``timezone`` (the API host's local time) — so it is never auto-set again.
+# (a fresh install) lets the API follow Home Assistant's reported zone
+# and the admin UI auto-set the browser's zone once while none is
+# stored; ``True`` pins the stored value — including an explicitly-chosen
+# empty ``timezone`` (the API host's local time) — so neither changes it.
 CONF_TIMEZONE_CONFIGURED = "timezone_configured"
 DEFAULT_TIMEZONE_CONFIGURED = False
+# The panel-plane request header carrying Home Assistant's configured
+# IANA ``time_zone`` from the integration to the API service.
+PANEL_TIMEZONE_HEADER = "X-NestQuest-Timezone"
 
 # Panel-plane API client (Feature 18): the integration reaches the
 # NestQuest API service (Feature 16) over HTTP instead of the database.

custom_components/nestquest/core/settings.py

@@ -327,12 +327,14 @@ class NestQuestSettings:
     def household_now(self, instant: datetime.datetime) -> datetime.datetime:
         """Return the aware ``instant`` expressed in the household's zone.
 
-        The API service has no Home Assistant ``time_zone``, so its one
+        The API service does not run inside Home Assistant, so its one
         clock read (an aware host-local ``now``) is converted here: with
-        :attr:`timezone` set the SAME instant is re-expressed in that
-        zone, so ``.date()`` and ``.time()`` are the household's wall
-        clock even when the host runs UTC.  With :attr:`timezone` empty
-        the instant is returned unchanged (the host's local time).
+        :attr:`timezone` set — the admin's choice, or else the zone the
+        integration reports from Home Assistant — the SAME instant is
+        re-expressed in that zone, so ``.date()`` and ``.time()`` are the
+        household's wall clock even when the host runs UTC.  With
+        :attr:`timezone` empty the instant is returned unchanged (the
+        host's local time).
         """
         if not self.timezone:
             return instant

custom_components/nestquest/core/settings_store.py

@@ -36,7 +36,8 @@ after the first update:
   this field existed simply lacks it and resolves to ``""``,
 - ``timezone_configured`` — a real boolean: ``True`` once the admin
   explicitly chose ``timezone`` (including the empty host-local value),
-  so the admin UI never auto-sets it again.  A document stored before
+  so neither Home Assistant's reported zone
+  (:func:`adopt_reported_timezone`) nor the admin UI changes it again.  A document stored before
   this field existed lacks it and resolves to ``False``.
 
 Only values whose core validators ACCEPTED are ever written, so a
@@ -200,18 +201,49 @@ async def update_settings(
         )
     async with _settings_lock(database):
         current = await load_settings(database)
-        document: dict[str, Any] = {
-            field: getattr(current, field) for field in _FIELD_NAMES
-        }
-        for name, raw_value in changes.items():
-            default, validator = _RESOLUTIONS[name]
-            try:
-                document[name] = validator(
-                    default if raw_value is None else raw_value
-                )
-            except ValueError as error:
-                raise ValueError(_named(name, error)) from error
-        await MetaStateDao(database).set(
-            SETTINGS_META_KEY, json.dumps(document, sort_keys=True)
-        )
+        return await _write_merged(database, current, changes)
+
+
+async def adopt_reported_timezone(
+    database: NestQuestDatabase, zone: str
+) -> NestQuestSettings:
+    """Adopt Home Assistant's reported ``zone`` unless the admin chose one.
+
+    While ``timezone_configured`` is ``False`` the stored ``timezone``
+    follows the zone the integration reports, so the API's clock is the
+    household's without any manual setup; ``timezone_configured`` stays
+    ``False`` (the value is automatic, not an admin choice).  Once the
+    admin has chosen — including an explicitly-chosen empty zone — the
+    stored settings are returned untouched.  The check and the write
+    share the settings lock, so a concurrent admin choice is never
+    overwritten.  An invalid ``zone`` raises a ``ValueError`` naming
+    ``timezone`` and writes nothing.
+    """
+    async with _settings_lock(database):
+        current = await load_settings(database)
+        if current.timezone_configured or current.timezone == zone:
+            return current
+        return await _write_merged(database, current, {"timezone": zone})
+
+
+async def _write_merged(
+    database: NestQuestDatabase,
+    current: NestQuestSettings,
+    changes: Mapping[str, Any],
+) -> NestQuestSettings:
+    """Validate ``changes``, merge onto ``current``, persist; lock held."""
+    document: dict[str, Any] = {
+        field: getattr(current, field) for field in _FIELD_NAMES
+    }
+    for name, raw_value in changes.items():
+        default, validator = _RESOLUTIONS[name]
+        try:
+            document[name] = validator(
+                default if raw_value is None else raw_value
+            )
+        except ValueError as error:
+            raise ValueError(_named(name, error)) from error
+    await MetaStateDao(database).set(
+        SETTINGS_META_KEY, json.dumps(document, sort_keys=True)
+    )
     return NestQuestSettings(**document)