Preload cached stations at launch (all tabs populate instantly); alert handler falls back to cache on background wake, restores enabled/fuel/radius in monitor init, re-registers geofences on setEnabled

FuelBoard/ProximityMonitor.swift

@@ -25,12 +25,21 @@ final class ProximityMonitor: NSObject, ObservableObject, @preconcurrency CLLoca
         manager.delegate = self
         manager.desiredAccuracy = kCLLocationAccuracyHundredMeters
         manager.pausesLocationUpdatesAutomatically = true
+        // Restore persisted state on background relaunch so region events work
+        // even before the view fully appears.
+        enabled = FuelStore.loadAlertsEnabled()
+        fuel = FuelStore.loadSelectedFuel()
+        radiusKM = FuelStore.loadAlertsRadius()
+        stations = FuelStore.loadStations()
+        favourites = FuelStore.loadFavourites()
     }
 
     /// Re-registers geofences. Call whenever stations/favourites/settings change.
     func update(stations: [FuelStation], favourites: [FuelStation], fuel: FuelType, radiusKM: Double) {
-        self.stations = stations
-        self.favourites = favourites
+        // Fall back to the shared cache when called before the first fetch
+        // completes (launch, background region-event wake).
+        self.stations = stations.isEmpty ? FuelStore.loadStations() : stations
+        self.favourites = favourites.isEmpty ? FuelStore.loadFavourites() : favourites
         self.fuel = fuel
         self.radiusKM = radiusKM
 
@@ -78,6 +87,8 @@ final class ProximityMonitor: NSObject, ObservableObject, @preconcurrency CLLoca
             monitoredStationIDs = []
         } else {
             requestPermissions()
+            // Re-register geofences from restored cache immediately.
+            update(stations: stations, favourites: favourites, fuel: fuel, radiusKM: radiusKM)
         }
     }
 
@@ -111,6 +122,9 @@ final class ProximityMonitor: NSObject, ObservableObject, @preconcurrency CLLoca
 
     private func handleEntry(_ region: CLRegion) {
         let stationID = region.identifier
+        // Fall back to cached data on background wake (stations may not be
+        // fetched yet when the app is relaunched by a region event).
+        if stations.isEmpty { stations = FuelStore.loadStations() }
         guard let station = stations.first(where: { $0.id == stationID }) else { return }
 
         // Dedup: one alert per station per hour.
@@ -128,9 +142,9 @@ final class ProximityMonitor: NSObject, ObservableObject, @preconcurrency CLLoca
                 }
                 guard let cheapest = withinRadius.min(by: { $0.prices[fuel]! < $1.prices[fuel]! }),
                       cheapest.id == station.id,
-                      let price = station.prices[fuel] else { return }
+                      let price = cheapest.prices[fuel] else { return }
 
-                fireAlert(for: station, price: price)
+                fireAlert(for: cheapest, price: price)
                 lastNotified[stationID] = Date()
             } catch {
                 // Silent — geofence state stays valid for next entry.