Add dismissable top banner for Nightscout, Dexcom, and heartbeat issues

LoopFollow.xcodeproj/project.pbxproj

@@ -67,9 +67,11 @@
 		65E153C32E4BB69100693A4F /* URLTokenValidationView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 65E153C22E4BB69100693A4F /* URLTokenValidationView.swift */; };
 		65E8A2862E44B0300065037B /* VolumeButtonHandler.swift in Sources */ = {isa = PBXBuildFile; fileRef = 65E8A2852E44B0300065037B /* VolumeButtonHandler.swift */; };
 		66E3D12E66AA4534A144A54B /* BackgroundRefreshManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = A8CA8BE0B3D247408FE088B4 /* BackgroundRefreshManager.swift */; };
+		87F526CE28FD073330D2F516 /* BannerManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = 098BA6FC4279B166734A0E13 /* BannerManager.swift */; };
+		8897B18D53EA2F1963B8B4E0 /* AppBannerView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8000BC181BCE5AA8553FB3B6 /* AppBannerView.swift */; };
+		9C7FB98C98BE4FF98F4815EE /* Telemetry.swift in Sources */ = {isa = PBXBuildFile; fileRef = BDFBE69CEF18416D84959974 /* Telemetry.swift */; };
 		92664FA270DA9905E1F08676 /* BGChartStubs.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6C508E0E86BEC0B13280F34B /* BGChartStubs.swift */; };
 		9727B75402723679BD39CDE5 /* DBSizeTask.swift in Sources */ = {isa = PBXBuildFile; fileRef = EBE9ECA96BEA20DBD21B570D /* DBSizeTask.swift */; };
-		9C7FB98C98BE4FF98F4815EE /* Telemetry.swift in Sources */ = {isa = PBXBuildFile; fileRef = BDFBE69CEF18416D84959974 /* Telemetry.swift */; };
 		9F24B79D2722BB040AE3311F /* BGChartModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7C8CB992D98689FC7D019CEC /* BGChartModel.swift */; };
 		A1A1A10001000000A0CFEED1 /* APNsCredentialValidator.swift in Sources */ = {isa = PBXBuildFile; fileRef = A1A1A10001000000A0CFEED2 /* APNsCredentialValidator.swift */; };
 		A1A1A10002000000A0CFEED1 /* LogRedactor.swift in Sources */ = {isa = PBXBuildFile; fileRef = A1A1A10002000000A0CFEED2 /* LogRedactor.swift */; };
@@ -474,6 +476,7 @@
 
 /* Begin PBXFileReference section */
 		059B0FA59AABFE72FE13DDDA /* Pods-LoopFollow.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-LoopFollow.release.xcconfig"; path = "Target Support Files/Pods-LoopFollow/Pods-LoopFollow.release.xcconfig"; sourceTree = "<group>"; };
+		098BA6FC4279B166734A0E13 /* BannerManager.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = BannerManager.swift; sourceTree = "<group>"; };
 		21EBF6ACF259782445DA1A7E /* DBSizeAlarmEditor.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = DBSizeAlarmEditor.swift; sourceTree = "<group>"; };
 		2B9BEC26E4E48EF9B811A372 /* PendingFutureCarb.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PendingFutureCarb.swift; sourceTree = "<group>"; };
 		2EBAB9EECE7095238A558060 /* FutureCarbsCondition.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FutureCarbsCondition.swift; sourceTree = "<group>"; };
@@ -528,6 +531,7 @@
 		65A100022F5AA00000AA1002 /* UnitsConfigurationView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UnitsConfigurationView.swift; sourceTree = "<group>"; };
 		65E153C22E4BB69100693A4F /* URLTokenValidationView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = URLTokenValidationView.swift; sourceTree = "<group>"; };
 		65E8A2852E44B0300065037B /* VolumeButtonHandler.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = VolumeButtonHandler.swift; sourceTree = "<group>"; };
+		8000BC181BCE5AA8553FB3B6 /* AppBannerView.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = AppBannerView.swift; sourceTree = "<group>"; };
 		6C508E0E86BEC0B13280F34B /* BGChartStubs.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = BGChartStubs.swift; sourceTree = "<group>"; };
 		7C8CB992D98689FC7D019CEC /* BGChartModel.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = BGChartModel.swift; sourceTree = "<group>"; };
 		8B81E18A2489A364AFC0A9E4 /* DBSize.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = DBSize.swift; sourceTree = "<group>"; };
@@ -1042,6 +1046,16 @@
 			path = Settings;
 			sourceTree = "<group>";
 		};
+		6A3463E271ADFF0E844E3E61 /* Banner */ = {
+			isa = PBXGroup;
+			children = (
+				098BA6FC4279B166734A0E13 /* BannerManager.swift */,
+				8000BC181BCE5AA8553FB3B6 /* AppBannerView.swift */,
+			);
+			name = Banner;
+			path = Banner;
+			sourceTree = "<group>";
+		};
 		6A5880E0B811AF443B05AB02 /* Frameworks */ = {
 			isa = PBXGroup;
 			children = (
@@ -1717,6 +1731,7 @@
 				DDC7E5CD2DC6637800EB1127 /* Storage */,
 				DDEF503D2D32753A00999A5D /* Task */,
 				FCC68871248A736700A0279D /* ViewControllers */,
+				6A3463E271ADFF0E844E3E61 /* Banner */,
 				CC1E389FE3B6E6EA3184474B /* Charts */,
 			);
 			path = LoopFollow;
@@ -2480,6 +2495,8 @@
 				DDEF50422D479BAA00884336 /* LoopAPNSCarbsView.swift in Sources */,
 				DDEF50432D479BBA00884336 /* LoopAPNSBolusView.swift in Sources */,
 				DDEF50452D479BDA00884336 /* LoopAPNSRemoteView.swift in Sources */,
+				87F526CE28FD073330D2F516 /* BannerManager.swift in Sources */,
+				8897B18D53EA2F1963B8B4E0 /* AppBannerView.swift in Sources */,
 				9F24B79D2722BB040AE3311F /* BGChartModel.swift in Sources */,
 				2F99F2B5C902F3018383C086 /* BGChartView.swift in Sources */,
 				92664FA270DA9905E1F08676 /* BGChartStubs.swift in Sources */,

LoopFollow/Application/MainTabView.swift

@@ -13,6 +13,7 @@ struct MainTabView: View {
     @ObservedObject private var snoozerPosition = Storage.shared.snoozerPosition
     @ObservedObject private var statisticsPosition = Storage.shared.statisticsPosition
     @ObservedObject private var treatmentsPosition = Storage.shared.treatmentsPosition
+    @ObservedObject private var activeBanner = Observable.shared.activeBanner
 
     @State private var showTelemetryConsent = false
 
@@ -21,6 +22,21 @@ struct MainTabView: View {
     }
 
     var body: some View {
+        // The banner sits in a VStack above the TabView (rather than a
+        // .safeAreaInset) so the UIKit-hosted Home content is physically
+        // pushed down too — safe-area changes don't propagate into
+        // UIViewControllerRepresentable.
+        VStack(spacing: 0) {
+            if let message = activeBanner.value {
+                AppBannerView(message: message)
+                    .transition(.move(edge: .top).combined(with: .opacity))
+            }
+            tabView
+        }
+        .animation(.easeInOut(duration: 0.25), value: activeBanner.value)
+    }
+
+    private var tabView: some View {
         TabView(selection: $selectedTab.value) {
             ForEach(Array(orderedItems.prefix(4).enumerated()), id: \.element) { index, item in
                 tabContent(for: item)

LoopFollow/BackgroundRefresh/BT/BLEManager.swift

@@ -13,6 +13,21 @@ class BLEManager: NSObject, ObservableObject {
     private var centralManager: CBCentralManager!
     private var activeDevice: BluetoothDevice?
 
+    /// Arrival times of recent heartbeat dropouts. Main-queue-confined
+    /// (centralManager delivers on .main) and deliberately not persisted:
+    /// stale history must not resurrect the banner after a relaunch.
+    private var heartbeatDropoutTimes: [Date] = []
+
+    /// A beat this much later than expected counts as one dropout event.
+    /// Stricter than the 15% logging margin - normal jitter must not count.
+    private let dropoutFactor = 1.5
+
+    /// Sliding window over which dropout events are counted.
+    private let dropoutWindow: TimeInterval = 60 * 60
+
+    /// Dropout events within the window needed to raise the banner.
+    private let dropoutTriggerCount = 5
+
     override private init() {
         super.init()
 
@@ -49,6 +64,8 @@ class BLEManager: NSObject, ObservableObject {
             activeDevice = nil
             device.lastHeartbeatTime = nil
         }
+        heartbeatDropoutTimes.removeAll()
+        BannerManager.shared.clear(.heartbeat)
         Storage.shared.selectedBLEDevice.value = nil
     }
 
@@ -208,6 +225,7 @@ extension BLEManager: BluetoothDeviceDelegate {
                 let delay = elapsedTime - expectedInterval
                 LogManager.shared.log(category: .bluetooth, message: "Heartbeat triggered (Delayed by \(String(format: "%.1f", delay)) seconds)")
             }
+            recordHeartbeatOutcome(elapsed: elapsedTime, expectedInterval: expectedInterval, now: now)
         } else {
             LogManager.shared.log(category: .bluetooth, message: "Heartbeat triggered (First heartbeat)")
         }
@@ -216,6 +234,55 @@ extension BLEManager: BluetoothDeviceDelegate {
 
         TaskScheduler.shared.checkTasksNow()
     }
+
+    /// Counts late heartbeats over a sliding window and raises a banner when
+    /// dropouts become frequent - the typical symptom of a dying transmitter
+    /// battery. Detection is arrival-based on purpose: a struggling battery
+    /// still delivers (late) beats, whereas total silence usually means
+    /// out-of-range or a dead device and is already surfaced by the
+    /// connection status in Background Refresh settings and by BG alarms.
+    private func recordHeartbeatOutcome(elapsed: TimeInterval, expectedInterval: TimeInterval, now: Date) {
+        heartbeatDropoutTimes.removeAll { now.timeIntervalSince($0) > dropoutWindow }
+
+        // A gap this large means out-of-range, Bluetooth off or a suspended
+        // app - not a struggling battery. Discard the history collected
+        // before the blind spot instead of counting it.
+        let resetGap = max(6 * expectedInterval, 30 * 60)
+        if elapsed > resetGap {
+            if !heartbeatDropoutTimes.isEmpty {
+                heartbeatDropoutTimes.removeAll()
+                LogManager.shared.log(category: .bluetooth, message: "Heartbeat gap of \(Int(elapsed)) seconds, resetting dropout history")
+            }
+        } else if elapsed > expectedInterval * dropoutFactor {
+            heartbeatDropoutTimes.append(now)
+            LogManager.shared.log(category: .bluetooth, message: "Heartbeat dropout recorded (\(heartbeatDropoutTimes.count) in the last hour)")
+        }
+
+        // Hysteresis: raise at the trigger count, clear only once the window
+        // is completely clean, so the banner doesn't flap at the boundary.
+        if heartbeatDropoutTimes.count >= dropoutTriggerCount {
+            BannerManager.shared.report(source: .heartbeat, severity: .warning, text: heartbeatDropoutBannerText())
+        } else if heartbeatDropoutTimes.isEmpty {
+            BannerManager.shared.clear(.heartbeat)
+        }
+    }
+
+    /// The text must stay stable while the condition persists (no counts or
+    /// durations) so BannerManager's dedupe keeps the banner from
+    /// re-animating on every beat and user dismissal keeps working.
+    private func heartbeatDropoutBannerText() -> String {
+        let name = activeDevice?.deviceName ?? "heartbeat device"
+        let cause: String
+        switch Storage.shared.backgroundRefreshType.value {
+        case .rileyLink:
+            cause = "a low RileyLink battery"
+        case .omnipodDash:
+            cause = "a low pod battery"
+        default:
+            cause = "a low transmitter battery"
+        }
+        return "Heartbeat: repeated Bluetooth dropouts from \(name). This can be a sign of \(cause) or a weak Bluetooth connection."
+    }
 }
 
 extension BLEManager {

LoopFollow/Banner/AppBannerView.swift

@@ -0,0 +1,75 @@
+// LoopFollow
+// AppBannerView.swift
+
+import SwiftUI
+
+/// Dismissable banner shown at the top of the app, above the tab content.
+struct AppBannerView: View {
+    let message: BannerMessage
+
+    var body: some View {
+        HStack(alignment: .top, spacing: 12) {
+            Image(systemName: iconName)
+                .font(.title3)
+                .foregroundColor(iconColor)
+
+            Text(message.text)
+                .font(.callout)
+                .lineLimit(3)
+                .fixedSize(horizontal: false, vertical: true)
+                .frame(maxWidth: .infinity, alignment: .leading)
+
+            Button {
+                BannerManager.shared.dismissCurrent()
+            } label: {
+                Image(systemName: "xmark.circle.fill")
+                    .font(.title3)
+                    .foregroundColor(.secondary)
+            }
+            .accessibilityLabel("Dismiss")
+        }
+        .padding()
+        .background(
+            RoundedRectangle(cornerRadius: 12, style: .continuous)
+                .fill(tint)
+        )
+        .overlay(
+            RoundedRectangle(cornerRadius: 12, style: .continuous)
+                .stroke(border, lineWidth: 1)
+        )
+        .padding(.horizontal, 10)
+        .padding(.vertical, 4)
+    }
+
+    private var iconName: String {
+        switch message.severity {
+        case .info: return "info.circle.fill"
+        case .warning: return "exclamationmark.triangle.fill"
+        case .error: return "xmark.octagon.fill"
+        }
+    }
+
+    private var iconColor: Color {
+        switch message.severity {
+        case .info: return .blue
+        case .warning: return .orange
+        case .error: return .red
+        }
+    }
+
+    private var tint: Color {
+        switch message.severity {
+        case .info: return Color.blue.opacity(0.20)
+        case .warning: return Color.orange.opacity(0.20)
+        case .error: return Color.red.opacity(0.20)
+        }
+    }
+
+    private var border: Color {
+        switch message.severity {
+        case .info: return Color.blue.opacity(0.40)
+        case .warning: return Color.orange.opacity(0.40)
+        case .error: return Color.red.opacity(0.40)
+        }
+    }
+}