fix: deduplicate pollingPhase MQTT publishes (#436)

* fix: deduplicate pollingPhase MQTT publishes

__publish_polling_phase() was called on every polling cycle via
should_refresh(), publishing the phase to MQTT even when unchanged.
Track the current phase and skip redundant publishes, matching the
existing deduplication pattern in set_refresh_mode().

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* test: add A->B->A transition test for polling phase dedup

Verifies that the deduplication correctly re-publishes a phase after
an intervening different phase (OFF -> FORCE -> OFF publishes 3 times).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: nanomad

src/vehicle.py

@@ -130,6 +130,7 @@ def __init__(
         self.charge_polling_min_percent = charge_polling_min_percent
         self.refresh_mode = RefreshMode.OFF
         self.previous_refresh_mode = RefreshMode.OFF
+        self.__polling_phase: PollingPhase | None = None
         self.__remote_ac_temp: int | None = None
         self.__remote_ac_running: bool = False
         self.__remote_heated_seats_front_left_level: int = 0
@@ -710,6 +711,9 @@ def get_topic(self, sub_topic: str) -> str:
         return f"{self.mqtt_vin_prefix}/{sub_topic}"
 
     def __publish_polling_phase(self, phase: PollingPhase) -> None:
+        if self.__polling_phase == phase:
+            return
+        self.__polling_phase = phase
         self.publisher.publish_str(
             self.get_topic(mqtt_topics.REFRESH_POLLING_PHASE), phase.value
         )

tests/mocks/__init__.py

@@ -15,8 +15,10 @@ class MessageCapturingConsolePublisher(ConsolePublisher):
     def __init__(self, configuration: Configuration) -> None:
         super().__init__(configuration)
         self.map: dict[str, Any] = {}
+        self.publish_count: dict[str, int] = {}
 
     @override
     def internal_publish(self, key: str, value: Any) -> None:
         self.map[key] = value
+        self.publish_count[key] = self.publish_count.get(key, 0) + 1
         LOG.debug(f"{key}: {value}")

tests/test_vehicle_state.py

@@ -486,6 +486,45 @@ def test_charging_stop_triggers_after_shutdown_grace(self) -> None:
             PollingPhase.AFTER_SHUTDOWN.value,
         )
 
+    def test_polling_phase_not_republished_when_unchanged(self) -> None:
+        """Calling should_refresh() twice with the same state should only publish the phase once."""
+        self.vehicle_state.configure_missing()
+        self.vehicle_state.set_refresh_mode(RefreshMode.OFF, "test")
+        self.publisher.map.clear()
+        self.publisher.publish_count.clear()
+
+        self.vehicle_state.should_refresh()
+        self.vehicle_state.should_refresh()
+
+        phase_topic = self.get_topic(mqtt_topics.REFRESH_POLLING_PHASE)
+        assert self.publisher.publish_count.get(phase_topic, 0) == 1
+
+    def test_polling_phase_republished_after_transition_back(self) -> None:
+        """A->B->A transition must publish all three phases (not suppress the return to A)."""
+        self.vehicle_state.configure_missing()
+        # Start with OFF (phase A)
+        self.vehicle_state.set_refresh_mode(RefreshMode.OFF, "test")
+        self.publisher.map.clear()
+        self.publisher.publish_count.clear()
+
+        # Phase A: OFF
+        self.vehicle_state.should_refresh()
+        phase_topic = self.get_topic(mqtt_topics.REFRESH_POLLING_PHASE)
+        assert self.publisher.map[phase_topic] == PollingPhase.OFF.value
+        assert self.publisher.publish_count[phase_topic] == 1
+
+        # Phase B: FORCE (one-shot, reverts to PERIODIC)
+        self.vehicle_state.set_refresh_mode(RefreshMode.FORCE, "test")
+        self.vehicle_state.should_refresh()
+        assert self.publisher.map[phase_topic] == PollingPhase.FORCE.value
+        assert self.publisher.publish_count[phase_topic] == 2
+
+        # Phase A again: back to OFF
+        self.vehicle_state.set_refresh_mode(RefreshMode.OFF, "test")
+        self.vehicle_state.should_refresh()
+        assert self.publisher.map[phase_topic] == PollingPhase.OFF.value
+        assert self.publisher.publish_count[phase_topic] == 3
+
     @staticmethod
     def get_topic(sub_topic: str) -> str:
         return f"/vehicles/{VIN}/{sub_topic}"