Add Smart data checking mode

FuelBoard/ContentView.swift

@@ -16,6 +16,7 @@ struct ContentView: View {
 
     @State private var stations: [FuelStation] = FuelStore.loadStations()
     @State private var selectedFuel: FuelType = FuelStore.loadSelectedFuel()
+    @State private var dataRefreshMode: DataRefreshMode = FuelStore.loadDataRefreshMode()
     @State private var sortMode: SortMode = FuelStore.loadSortMode()
     @State private var stationLimit: Int = FuelStore.loadStationLimit()
     @State private var distanceUnit: DistanceUnit = FuelStore.loadDistanceUnit()
@@ -365,6 +366,7 @@ struct ContentView: View {
             if !showing, FuelStore.loadHasCompletedOnboarding() {
                 locationManager.startForegroundTracking()
                 installLocationUpdateHook()
+                SmartDataRefreshScheduler.scheduleNextIfNeeded()
                 ensureBackgroundMotionTrackingIfNeeded()
                 monitor.update(stations: stations, favourites: refreshedFavourites,
                                fuel: alertsFuel, radiusKM: effectiveAlertsRadiusKM)
@@ -380,6 +382,7 @@ struct ContentView: View {
                 if !showOnboarding, FuelStore.loadHasCompletedOnboarding() {
                     locationManager.startForegroundTracking()
                 }
+                SmartDataRefreshScheduler.scheduleNextIfNeeded()
                 monitor.update(stations: stations, favourites: refreshedFavourites,
                                fuel: alertsFuel, radiusKM: effectiveAlertsRadiusKM)
                 updateLiveActivity()
@@ -787,6 +790,7 @@ struct ContentView: View {
             tipStore: tipStore,
             distanceUnit: $distanceUnit,
             priceDisplayStyle: $priceDisplayStyle,
+            dataRefreshMode: $dataRefreshMode,
             alertsFuel: alertsFuel,
             alertsRadiusKM: alertsRadius,
             testAlertResult: monitor.lastTestResult,
@@ -849,6 +853,7 @@ struct ContentView: View {
             stations = fetched
             FuelStore.saveStations(fetched)
             FuelStore.saveLastRefresh()
+            FuelStore.saveLastSmartProbe()
             // Persist envelope metadata (source, station count, GOV.UK
             // dataset update time) for the Settings → About section — the
             // live chain records whichever leg served the fetch.

FuelBoard/FuelBoardApp.swift

@@ -1,4 +1,5 @@
 import ActivityKit
+import BackgroundTasks
 import SwiftUI
 
 @main
@@ -22,6 +23,9 @@ struct FuelBoardApp: App {
             ContentView()
                 .onOpenURL(perform: handleOpenURL)
         }
+        .backgroundTask(.appRefresh(SmartDataRefreshScheduler.taskIdentifier)) {
+            await SmartDataRefreshCoordinator.runBackgroundProbe()
+        }
     }
 
     #if DEBUG

FuelBoard/SettingsView.swift

@@ -18,6 +18,7 @@ struct SettingsView: View {
     @ObservedObject var tipStore: TipStore
     @Binding var distanceUnit: DistanceUnit
     @Binding var priceDisplayStyle: PriceDisplayStyle
+    @Binding var dataRefreshMode: DataRefreshMode
     /// The fuel + radius currently configured for alerts (mirrors the Alerts
     /// tab) so the test notification matches what real alerts will say.
     var alertsFuel: FuelType = .e10
@@ -120,6 +121,29 @@ struct SettingsView: View {
                     Text("Distances and search radii across the app, widget and alerts are shown in this unit. Prices can be shown as on a station sign (129.9) or in pounds and pence (£1.29⁹/L).")
                 }
 
+                Section {
+                    Picker("Data checking", selection: $dataRefreshMode) {
+                        ForEach(DataRefreshMode.allCases) { mode in
+                            Text(mode.displayName).tag(mode)
+                        }
+                    }
+                    .pickerStyle(.segmented)
+                    .onChange(of: dataRefreshMode) { _, newValue in
+                        FuelStore.saveDataRefreshMode(newValue)
+                        SmartDataRefreshScheduler.scheduleNextIfNeeded()
+                    }
+                    VStack(alignment: .leading, spacing: 8) {
+                        Text(dataRefreshMode.summary)
+                        Text("Background checks are best-effort and happen only when iOS allows, so timing is not exact.")
+                            .foregroundStyle(.secondary)
+                    }
+                    .font(.footnote)
+                } header: {
+                    Text("Data checking")
+                } footer: {
+                    Text("Standard saves battery and refreshes price data up to twice daily. Smart checks for newer data more often in the background and only refreshes full prices when an update is available.")
+                }
+
                 Section {
                     Button {
                         onShowOnboarding()

FuelBoard/SmartDataRefresh.swift

@@ -0,0 +1,88 @@
+import BackgroundTasks
+import Foundation
+import WidgetKit
+
+enum SmartDataRefreshScheduler {
+    static let taskIdentifier = "com.apt.fuelboard.smart-refresh"
+
+    static func register() {
+        BGTaskScheduler.shared.register(forTaskWithIdentifier: taskIdentifier, using: nil) { task in
+            guard let task = task as? BGAppRefreshTask else {
+                task.setTaskCompleted(success: false)
+                return
+            }
+            handle(task)
+        }
+    }
+
+    static func scheduleNextIfNeeded() {
+        BGTaskScheduler.shared.cancel(taskRequestWithIdentifier: taskIdentifier)
+        guard FuelStore.loadDataRefreshMode() == .smart else { return }
+        let request = BGAppRefreshTaskRequest(identifier: taskIdentifier)
+        request.earliestBeginDate = Date(timeIntervalSinceNow: FuelStore.smartProbeInterval)
+        do {
+            try BGTaskScheduler.shared.submit(request)
+        } catch {
+            #if DEBUG
+            print("SMART-REFRESH schedule failed: \(error)")
+            #endif
+        }
+    }
+
+    private static func handle(_ task: BGAppRefreshTask) {
+        scheduleNextIfNeeded()
+        let refreshTask = Task {
+            let success = await SmartDataRefreshCoordinator.runBackgroundProbe()
+            task.setTaskCompleted(success: success)
+        }
+        task.expirationHandler = {
+            refreshTask.cancel()
+        }
+    }
+}
+
+enum SmartDataRefreshCoordinator {
+    @discardableResult
+    static func runBackgroundProbe(now: Date = Date()) async -> Bool {
+        guard FuelStore.loadDataRefreshMode() == .smart else { return true }
+        guard FuelStore.isSmartProbeDue(now: now) || FuelStore.loadStations().isEmpty else {
+            return true
+        }
+        FuelStore.saveLastSmartProbe(now)
+        guard !Task.isCancelled else { return false }
+
+        guard let latest = await FuelHistoryStore.fetchLatest() else {
+            return false
+        }
+
+        let latestDay = latest.availableTo ?? latest.date
+        let latestUpdated = latest.dataUpdated
+        let cachedDay = MirrorFuelProvider.loadDumpCache()?.day
+        let savedUpdated = FuelStore.loadDataUpdated()
+        let shouldFetchFullDump = FuelStore.loadStations().isEmpty
+            || !FuelStore.isCacheFresh(now: now)
+            || (latestDay != nil && latestDay != cachedDay)
+            || (latestUpdated != nil && latestUpdated != savedUpdated)
+
+        guard shouldFetchFullDump, !Task.isCancelled else { return true }
+
+        do {
+            let fetched = try await FuelPriceProvider.active.fetchStations(
+                near: nil,
+                lng: nil,
+                fuel: FuelStore.loadSelectedFuel(),
+                radiusKM: nil
+            )
+            guard !Task.isCancelled else { return false }
+            FuelStore.saveStations(fetched)
+            FuelStore.saveLastRefresh(now)
+            if let meta = LiveChainProvider.latestMeta {
+                FuelStore.saveRelayMeta(meta)
+            }
+            WidgetCenter.shared.reloadAllTimelines()
+            return true
+        } catch {
+            return false
+        }
+    }
+}