From bec6cdac0522e2ca0eda28e3a6032e8878fd5d05 Mon Sep 17 00:00:00 2001
From: Stefan Ceriu <stefanc@matrix.org>
Date: Tue, 21 Nov 2023 10:59:10 +0200
Subject: [PATCH] Secure backup tweaks (#2122)

* Show the recovery section if key backup is anything **but** disabled

* Don't show an action on secure backup if its current state is unknown

* Do not show a badge on the home screen avatar while the recovery state is unknown

* Do not assume key backup is disabled when its state is unknown. If the state is unknown, check if a backup exists remotely.

* Dedupe remote backup state requests and handle task cancellations
---
 .../HomeScreen/HomeScreenViewModel.swift      |  2 +-
 .../View/SecureBackupScreen.swift             |  6 ++-
 .../SecureBackup/SecureBackupController.swift | 40 ++++++++++++++++++-
 3 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/ElementX/Sources/Screens/HomeScreen/HomeScreenViewModel.swift b/ElementX/Sources/Screens/HomeScreen/HomeScreenViewModel.swift
index d4be6994b..81834dcd5 100644
--- a/ElementX/Sources/Screens/HomeScreen/HomeScreenViewModel.swift
+++ b/ElementX/Sources/Screens/HomeScreen/HomeScreenViewModel.swift
@@ -85,7 +85,7 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
             .sink { [weak self] recoveryKeyState in
                 guard let self, appSettings.chatBackupEnabled else { return }
                 
-                let requiresSecureBackupSetup = recoveryKeyState == .unknown || recoveryKeyState == .disabled || recoveryKeyState == .incomplete
+                let requiresSecureBackupSetup = recoveryKeyState == .disabled || recoveryKeyState == .incomplete
                 
                 state.showUserMenuBadge = requiresSecureBackupSetup
                 state.showSettingsMenuOptionBadge = requiresSecureBackupSetup
diff --git a/ElementX/Sources/Screens/SecureBackup/SecureBackupScreen/View/SecureBackupScreen.swift b/ElementX/Sources/Screens/SecureBackup/SecureBackupScreen/View/SecureBackupScreen.swift
index 990478c7b..0f19bf279 100644
--- a/ElementX/Sources/Screens/SecureBackup/SecureBackupScreen/View/SecureBackupScreen.swift
+++ b/ElementX/Sources/Screens/SecureBackup/SecureBackupScreen/View/SecureBackupScreen.swift
@@ -23,7 +23,7 @@ struct SecureBackupScreen: View {
     
     var body: some View {
         Form {
-            if context.viewState.keyBackupState != .enabled {
+            if context.viewState.keyBackupState == .disabled {
                 keyBackupSection
             } else {
                 keyBackupSection
@@ -77,10 +77,12 @@ struct SecureBackupScreen: View {
             ListRow(label: .plain(title: L10n.screenChatBackupKeyBackupActionDisable, role: .destructive), kind: .navigationLink {
                 context.send(viewAction: .keyBackup)
             })
-        case .disabled, .enabling, .unknown:
+        case .disabled, .enabling:
             ListRow(label: .plain(title: L10n.screenChatBackupKeyBackupActionEnable), kind: .navigationLink {
                 context.send(viewAction: .keyBackup)
             })
+        case .unknown:
+            EmptyView()
         }
     }
     
diff --git a/ElementX/Sources/Services/SecureBackup/SecureBackupController.swift b/ElementX/Sources/Services/SecureBackup/SecureBackupController.swift
index f5d7f5d7e..95cbde9c7 100644
--- a/ElementX/Sources/Services/SecureBackup/SecureBackupController.swift
+++ b/ElementX/Sources/Services/SecureBackup/SecureBackupController.swift
@@ -27,6 +27,9 @@ class SecureBackupController: SecureBackupControllerProtocol {
     private var backupStateListenerTaskHandle: TaskHandle?
     private var recoveryStateListenerTaskHandle: TaskHandle?
     
+    /// Used to dedupe remote backup state requests
+    @CancellableTask private var remoteBackupStateTask: Task<Void, Error>?
+    
     var recoveryKeyState: CurrentValuePublisher<SecureBackupRecoveryKeyState, Never> {
         recoveryKeyStateSubject.asCurrentValuePublisher()
     }
@@ -39,11 +42,18 @@ class SecureBackupController: SecureBackupControllerProtocol {
         self.encryption = encryption
         
         backupStateListenerTaskHandle = encryption.backupStateListener(listener: SecureBackupControllerBackupStateListener { [weak self] state in
-            self?.keyBackupStateSubject.send(state.keyBackupState)
+            guard let self else { return }
+            
+            keyBackupStateSubject.send(state.keyBackupState)
+            
+            if case .unknown = state {
+                updateBackupStateFromRemote()
+            }
         })
         
         recoveryStateListenerTaskHandle = encryption.recoveryStateListener(listener: SecureBackupRecoveryStateListener { [weak self] state in
             guard let self else { return }
+            
             switch state {
             case .unknown:
                 recoveryKeyStateSubject.send(.unknown)
@@ -55,6 +65,8 @@ class SecureBackupController: SecureBackupControllerProtocol {
                 recoveryKeyStateSubject.send(.incomplete)
             }
         })
+        
+        updateBackupStateFromRemote()
     }
     
     func enable() async -> Result<Void, SecureBackupControllerError> {
@@ -140,6 +152,30 @@ class SecureBackupController: SecureBackupControllerProtocol {
             return .failure(.failedUploadingForBackup)
         }
     }
+    
+    // MARK: - Private
+    
+    private func updateBackupStateFromRemote(retry: Bool = true) {
+        remoteBackupStateTask = Task {
+            do {
+                let backupExists = try await self.encryption.backupExistsOnServer()
+                
+                if Task.isCancelled {
+                    return
+                }
+                
+                if !backupExists {
+                    keyBackupStateSubject.send(.disabled)
+                }
+            } catch {
+                MXLog.error("Failed retrieving remote backup state with error: \(error)")
+                
+                if retry {
+                    updateBackupStateFromRemote(retry: false)
+                }
+            }
+        }
+    }
 }
 
 private final class SecureBackupControllerBackupStateListener: BackupStateListener {
@@ -182,7 +218,7 @@ extension BackupState {
     var keyBackupState: SecureBackupKeyBackupState {
         switch self {
         case .unknown:
-            return .disabled
+            return .unknown
         case .creating:
             return .enabling
         case .enabling: