Show the paired sensor's warm-up time on the Sensor Paired screen

G7SensorKitUI/G7CGMManager/G7UICoordinator.swift

@@ -207,7 +207,7 @@ class G7UICoordinator: UINavigationController, CGMManagerOnboarding, CompletionN
             // advertised; `.g7` when it did not announce one, matching what
             // the pairing screen showed a moment ago.
             let model = deviceName.flatMap(G7SensorModel.init(advertisedName:)) ?? .g7
-            let view = G7PairingSuccessView(model: model, deviceName: deviceName, hasNextStep: offersShare) { [weak self] in
+            let view = G7PairingSuccessView(model: model, deviceName: deviceName, hasNextStep: offersShare, warmup: G7PairingWarmupModel(cgmManager: cgmManager)) { [weak self] in
                 guard let self = self else { return }
                 if offersShare {
                     self.navigate(to: .shareSignIn)

G7SensorKitUI/Localizable.xcstrings

@@ -433,8 +433,11 @@
     "%1$@ connects to your G7, ONE+ or Stelo sensor directly. Pair it with the 4-digit code printed on the sensor applicator, and the Dexcom app is not needed." : {
       "comment" : "Descriptive text on G7StartupView (1: appName)"
     },
-    "%1$@ is now connected to the sensor directly. Readings arrive every 5 minutes; a new sensor needs about 30 minutes to warm up first." : {
-      "comment" : "Body of the pairing success screen (1: appName)"
+    "%1$@ is now connected to the sensor directly. Readings arrive every 5 minutes after a %2$@ warm-up." : {
+      "comment" : "Body of the pairing success screen (1: appName, 2: warm-up duration, e.g. 27 minutes)"
+    },
+    "%1$@ is now connected to the sensor directly. Readings arrive every 5 minutes once the sensor has warmed up." : {
+      "comment" : "Body of the pairing success screen before the sensor reports its warm-up time (1: appName)"
     },
     "%1$@ will read glucose from the Dexcom app's session until you pair a sensor. The Dexcom app must stay installed for this to work." : {
       "comment" : "Explanation of eavesdropping mode on G7StartupView (1: appName)"

G7SensorKitUI/Views/Onboarding/G7PairingSuccessView.swift

@@ -15,10 +15,25 @@ struct G7PairingSuccessView: View {
     var deviceName: String?
     /// Whether setup continues after this page (Dexcom Share sign-in).
     var hasNextStep = false
+    @ObservedObject var warmup: G7PairingWarmupModel
     var didFinish: () -> Void
 
     @Environment(\.appName) private var appName
 
+    private var bodyText: String {
+        guard let duration = warmup.duration, let formatted = Self.durationFormatter.string(from: duration) else {
+            return String(format: LocalizedString("%1$@ is now connected to the sensor directly. Readings arrive every 5 minutes once the sensor has warmed up.", comment: "Body of the pairing success screen before the sensor reports its warm-up time (1: appName)"), appName)
+        }
+        return String(format: LocalizedString("%1$@ is now connected to the sensor directly. Readings arrive every 5 minutes after a %2$@ warm-up.", comment: "Body of the pairing success screen (1: appName, 2: warm-up duration, e.g. 27 minutes)"), appName, formatted)
+    }
+
+    private static let durationFormatter: DateComponentsFormatter = {
+        let formatter = DateComponentsFormatter()
+        formatter.allowedUnits = [.hour, .minute]
+        formatter.unitsStyle = .full
+        return formatter
+    }()
+
     var body: some View {
         // Laid out like the pairing screen this arrives from: the sensor
         // centred at the top, the text from one left edge under it, and the
@@ -42,7 +57,7 @@ struct G7PairingSuccessView: View {
                         }
                     }
 
-                    Text(String(format: LocalizedString("%1$@ is now connected to the sensor directly. Readings arrive every 5 minutes; a new sensor needs about 30 minutes to warm up first.", comment: "Body of the pairing success screen (1: appName)"), appName))
+                    Text(bodyText)
                         .foregroundColor(.secondary)
                         .fixedSize(horizontal: false, vertical: true)
 
@@ -65,3 +80,21 @@ struct G7PairingSuccessView: View {
         .navigationBarBackButtonHidden(true)
     }
 }
+
+/// The warm-up the sensor reports, which arrives shortly after pairing.
+final class G7PairingWarmupModel: ObservableObject, G7StateObserver {
+    @Published private(set) var duration: TimeInterval?
+
+    init(cgmManager: G7CGMManager?) {
+        duration = cgmManager?.state.extendedVersion?.warmupDuration
+        cgmManager?.addStateObserver(self, queue: .main)
+    }
+
+    func g7StateDidUpdate(_ state: G7CGMManagerState?) {
+        if let warmupDuration = state?.extendedVersion?.warmupDuration {
+            duration = warmupDuration
+        }
+    }
+
+    func g7ConnectionStatusDidChange() {}
+}