Add boot detection in the NSE and use this to inform the user that there may be more notifications. (#5054)

* Add an initial implementation of the receivedWhileOfflineNotification.

* Only deliver a single receivedWhileOffline notification per boot and clarify the API.

* Add a 15-minute threshold for the receiveWhileOfflineNotification.

ElementX/Sources/Application/Settings/AppSettings.swift

@@ -14,7 +14,9 @@ import Foundation
 import SwiftUI
 
 /// Common settings between app and NSE
-protocol CommonSettingsProtocol {
+protocol CommonSettingsProtocol: AnyObject {
+    var lastNotificationBootTime: TimeInterval? { get set }
+    
     var logLevel: LogLevel { get }
     var traceLogPacks: Set<TraceLogPack> { get }
     var bugReportRageshakeURL: RemotePreference<RageshakeConfiguration> { get }
@@ -51,6 +53,7 @@ final class AppSettings {
         case enableNotifications
         case enableInAppNotifications
         case pusherProfileTag
+        case lastNotificationBootTime
         case logLevel
         case traceLogPacks
         case viewSourceEnabled
@@ -291,6 +294,10 @@ final class AppSettings {
     @UserPreference(key: UserDefaultsKeys.pusherProfileTag, storageType: .userDefaults(store))
     var pusherProfileTag: String?
     
+    /// The device's last boot time as recorded by the NSE.
+    @UserPreference(key: UserDefaultsKeys.lastNotificationBootTime, storageType: .userDefaults(store))
+    var lastNotificationBootTime: TimeInterval?
+    
     // MARK: - Logging
         
     @UserPreference(key: UserDefaultsKeys.logLevel, defaultValue: LogLevel.info, storageType: .userDefaults(store))

ElementX/Sources/Generated/Strings.swift

@@ -1060,6 +1060,8 @@ internal enum L10n {
   internal static func notificationReactionBody(_ p1: Any) -> String {
     return L10n.tr("Localizable", "notification_reaction_body", String(describing: p1))
   }
+  /// You received one or more notifications while offline.
+  internal static var notificationReceivedWhileOfflineIos: String { return L10n.tr("Localizable", "notification_received_while_offline_ios") }
   /// Mark as read
   internal static var notificationRoomActionMarkAsRead: String { return L10n.tr("Localizable", "notification_room_action_mark_as_read") }
   /// Quick reply

ElementX/Sources/Other/Extensions/UNNotificationContent.swift

@@ -29,6 +29,10 @@ extension UNNotificationContent {
     @objc var threadRootEventID: String? {
         userInfo[NotificationConstants.UserInfoKey.threadRootEventIdentifier] as? String
     }
+    
+    var unreadCount: Int? {
+        userInfo[NotificationConstants.UserInfoKey.unreadCount] as? Int
+    }
 }
 
 extension UNMutableNotificationContent {
@@ -40,7 +44,7 @@ extension UNMutableNotificationContent {
             userInfo[NotificationConstants.UserInfoKey.receiverIdentifier] = newValue
         }
     }
-
+    
     override var roomID: String? {
         get {
             userInfo[NotificationConstants.UserInfoKey.roomIdentifier] as? String
@@ -67,8 +71,4 @@ extension UNMutableNotificationContent {
             userInfo[NotificationConstants.UserInfoKey.threadRootEventIdentifier] = newValue
         }
     }
-    
-    var unreadCount: Int? {
-        userInfo[NotificationConstants.UserInfoKey.unreadCount] as? Int
-    }
 }

ElementX/Sources/Services/Notification/Manager/NotificationManager.swift

@@ -56,8 +56,14 @@ final class NotificationManager: NSObject, NotificationManagerProtocol {
                 self?.enableNotifications(newValue)
             }
             .store(in: &cancellables)
-    }
         
+        NotificationCenter.default.publisher(for: UIApplication.didBecomeActiveNotification)
+            .sink { [weak self] _ in
+                self?.removeReceivedWhileOfflineNotification()
+            }
+            .store(in: &cancellables)
+    }
+    
     func requestAuthorization() {
         guard appSettings.enableNotifications, !userSession.isNil else { return }
         Task {
@@ -151,6 +157,10 @@ final class NotificationManager: NSObject, NotificationManagerProtocol {
         
         notificationCenter.removeDeliveredNotifications(withIdentifiers: notificationsIdentifiers)
     }
+    
+    private func removeReceivedWhileOfflineNotification() {
+        notificationCenter.removeDeliveredNotifications(withIdentifiers: [NotificationServiceExtension.receivedWhileOfflineNotificationID])
+    }
 
     private func setPusher(with deviceToken: Data, clientProxy: ClientProxyProtocol) async -> Bool {
         do {