Make GPS location persistence opt-in and fuzzed

config.yaml.example

@@ -176,10 +176,12 @@ gps:
   time_sync_min_offset_seconds: 1.0
   time_sync_min_valid_year: 2020
 
-  # Feed a valid GPS fix back into repeater.latitude/repeater.longitude so
-  # pyMC Repeater adverts and pyMC Console location details follow the receiver.
-  # Updates are throttled to avoid rewriting config on every NMEA sentence.
-  update_repeater_location_from_fix: true
+  # Opt-in: feed a valid GPS fix back into repeater.latitude/repeater.longitude
+  # so pyMC Repeater adverts and pyMC Console location details follow the
+  # receiver. repeater_location_precision_digits is applied before saving so
+  # deployments can fuzz the stored/advertised location. Updates are throttled
+  # to avoid rewriting config on every NMEA sentence.
+  update_repeater_location_from_fix: false
   location_update_interval_seconds: 600.0
 
 # Mesh Network Configuration

repeater/config.py

@@ -98,7 +98,7 @@ def load_config(config_path: Optional[str] = None) -> Dict[str, Any]:
             "time_sync_interval_seconds": 3600.0,
             "time_sync_min_offset_seconds": 1.0,
             "time_sync_min_valid_year": 2020,
-            "update_repeater_location_from_fix": True,
+            "update_repeater_location_from_fix": False,
             "location_update_interval_seconds": 600.0,
         }
 

repeater/data_acquisition/gps_service.py

@@ -619,10 +619,7 @@ class GPSService:
         self._clock_setter = clock_setter or _set_system_clock_from_datetime
         self._time_provider = time_provider or time.time
         self.location_update_enabled = bool(
-            gps_config.get(
-                "update_repeater_location_from_fix",
-                gps_config.get("use_gps_for_repeater_location", True),
-            )
+            gps_config.get("update_repeater_location_from_fix", False)
         )
         self.location_update_interval_seconds = max(
             1.0, float(gps_config.get("location_update_interval_seconds", 600.0))
@@ -879,22 +876,30 @@ class GPSService:
         if _is_zero_coordinate(latitude, longitude):
             return
 
+        effective_latitude = self._apply_precision(latitude)
+        effective_longitude = self._apply_precision(longitude)
+        if not _is_valid_latitude(effective_latitude) or not _is_valid_longitude(
+            effective_longitude
+        ):
+            return
+
         self._last_location_update_monotonic = now_monotonic
         payload = {
-            "latitude": latitude,
-            "longitude": longitude,
+            "latitude": effective_latitude,
+            "longitude": effective_longitude,
             "altitude_m": _to_float(position.get("altitude_m")),
             "fix": deepcopy(snapshot.get("fix") or {}),
             "status": deepcopy(snapshot.get("status") or {}),
             "time": deepcopy(snapshot.get("time") or {}),
+            "precision_digits": self.repeater_location_precision_digits,
         }
         try:
             updated = bool(self._location_update_callback(payload))
         except Exception as exc:
             self._record_location_update_status(
                 state="error",
-                latitude=latitude,
-                longitude=longitude,
+                latitude=effective_latitude,
+                longitude=effective_longitude,
                 error=f"{type(exc).__name__}: {exc}",
             )
             logger.warning("GPS repeater location update failed: %s", exc)
@@ -902,8 +907,8 @@ class GPSService:
 
         self._record_location_update_status(
             state="updated" if updated else "skipped",
-            latitude=latitude,
-            longitude=longitude,
+            latitude=effective_latitude,
+            longitude=effective_longitude,
             success=updated,
         )
 

tests/test_gps_service.py

@@ -464,6 +464,7 @@ def test_gps_service_updates_repeater_location_from_valid_fix(monkeypatch):
             "gps": {
                 "enabled": True,
                 "time_sync_enabled": False,
+                "update_repeater_location_from_fix": True,
                 "location_update_interval_seconds": 600.0,
             }
         },
@@ -503,6 +504,7 @@ def test_gps_service_does_not_update_repeater_location_without_valid_fix():
             "gps": {
                 "enabled": True,
                 "time_sync_enabled": False,
+                "update_repeater_location_from_fix": True,
             }
         },
         location_update_callback=lambda payload: location_updates.append(payload) or True,
@@ -516,14 +518,13 @@ def test_gps_service_does_not_update_repeater_location_without_valid_fix():
     assert service.get_snapshot()["location_update"]["state"] == "waiting_for_fix"
 
 
-def test_gps_service_honors_legacy_use_gps_for_repeater_location_flag():
+def test_gps_service_location_update_is_opt_in_by_default():
     location_updates = []
     service = GPSService(
         {
             "gps": {
                 "enabled": True,
                 "time_sync_enabled": False,
-                "use_gps_for_repeater_location": False,
             }
         },
         location_update_callback=lambda payload: location_updates.append(payload) or True,
@@ -535,3 +536,30 @@ def test_gps_service_honors_legacy_use_gps_for_repeater_location_flag():
 
     assert location_updates == []
     assert service.get_snapshot()["location_update"]["state"] == "disabled"
+
+
+def test_gps_service_fuzzes_persisted_repeater_location():
+    location_updates = []
+    service = GPSService(
+        {
+            "gps": {
+                "enabled": True,
+                "time_sync_enabled": False,
+                "update_repeater_location_from_fix": True,
+                "repeater_location_precision_digits": 3,
+            }
+        },
+        location_update_callback=lambda payload: location_updates.append(payload) or True,
+    )
+
+    assert service.ingest_sentence(
+        _sentence("GPGGA,010203,4250.123,N,07106.456,W,1,05,1.4,32.0,M,0.0,M,,")
+    )
+
+    assert len(location_updates) == 1
+    assert location_updates[0]["latitude"] == 42.835
+    assert location_updates[0]["longitude"] == -71.108
+    assert location_updates[0]["precision_digits"] == 3
+    snapshot = service.get_snapshot()
+    assert snapshot["location_update"]["last_latitude"] == 42.835
+    assert snapshot["location_update"]["last_longitude"] == -71.108