Fix #6820: Allow to permanently delete Sync accounts (#7031)

Sources/Brave/Frontend/Browser/BrowserViewController.swift

@@ -124,6 +124,7 @@ public class BrowserViewController: UIViewController {
   var pageZoomBar: UIHostingController<PageZoomView>?
   private var pageZoomListener: NSObjectProtocol?
   private var openTabsModelStateListener: SendTabToSelfModelStateListener?
+  private var syncServiceStateListener: AnyObject?
   let collapsedURLBarView = CollapsedURLBarView()
 
   // Single data source used for all favorites vcs
@@ -361,6 +362,16 @@ public class BrowserViewController: UIViewController {
           }
         }
       })
+
+    // Observer watching state change in sync chain
+    syncServiceStateListener = braveCore.syncAPI.addServiceStateObserver { [weak self] in
+      guard let self = self else { return }
+      // Observe Sync State in order to determine if the sync chain is deleted
+      // from another device - Clean local sync chain
+      if self.braveCore.syncAPI.shouldLeaveSyncGroup {
+        self.braveCore.syncAPI.leaveSyncGroup()
+      }
+    }
   }
 
   deinit {

Sources/Brave/Frontend/Browser/BrowserViewController/BrowserViewController+WKNavigationDelegate.swift

@@ -783,11 +783,11 @@ extension BrowserViewController {
       titleWeight: .semibold,
       titleSize: 21
     )
-    popup.addButton(title: Strings.openExternalAppURLDontAllow, fontSize: 16) { () -> PopupViewDismissType in
+    popup.addButton(title: Strings.openExternalAppURLDontAllow) { () -> PopupViewDismissType in
       removeTabIfEmpty()
       return .flyDown
     }
-    popup.addButton(title: Strings.openExternalAppURLAllow, type: .primary, fontSize: 16) { () -> PopupViewDismissType in
+    popup.addButton(title: Strings.openExternalAppURLAllow, type: .primary) { () -> PopupViewDismissType in
       UIApplication.shared.open(url, options: [:], completionHandler: openedURLCompletionHandler)
       removeTabIfEmpty()
       return .flyDown

Sources/Brave/Frontend/Browser/Tabs/TabTray/TabTrayController.swift

@@ -47,7 +47,8 @@ class TabTrayController: LoadingViewController {
   let tabManager: TabManager
   let braveCore: BraveCoreMain
   private var openTabsSessionServiceListener: OpenTabsSessionStateListener?
-
+  private var syncServicStateListener: AnyObject?
+
   weak var delegate: TabTrayDelegate?
   weak var toolbarUrlActionsDelegate: ToolbarUrlActionsDelegate?
 
@@ -200,6 +201,17 @@ class TabTrayController: LoadingViewController {
           }
         }
       })
+
+    // Adding State Sync Observer to watch the states change in sync chain
+    syncServicStateListener = braveCore.syncAPI.addServiceStateObserver { [weak self] in
+      guard let self = self else { return }
+
+      if self.braveCore.syncAPI.shouldLeaveSyncGroup {
+        self.tabSyncView.do {
+          $0.updateSyncStatusPanel(for: self.emptyPanelState)
+        }
+      }
+    }
   }
 
   @available(*, unavailable)

Sources/Brave/Frontend/Sync/BraveCore/BraveSyncAPIExtensions.swift

@@ -30,6 +30,15 @@ extension BraveSyncAPI {
   var isInSyncGroup: Bool {
     return Preferences.Chromium.syncEnabled.value
   }
+
+  /// Property that determines if the local sync chain should be resetted
+  var shouldLeaveSyncGroup: Bool {
+    guard isInSyncGroup else {
+      return false
+    }
+
+    return !(isSyncFeatureActive && isFirstSetupComplete) || isSyncAccountDeletedNoticePending
+  }
 
   var isSendTabToSelfVisible: Bool {
     guard let json = getDeviceListJSON(), let data = json.data(using: .utf8) else {
@@ -47,9 +56,11 @@ extension BraveSyncAPI {
 
   @discardableResult
   func joinSyncGroup(codeWords: String, syncProfileService: BraveSyncProfileServiceIOS) -> Bool {
-    if self.setSyncCode(codeWords) {
-      Preferences.Chromium.syncEnabled.value = true
+    if setSyncCode(codeWords) {
       enableSyncTypes(syncProfileService: syncProfileService)
+      requestSync()
+      setSetupComplete()
+      Preferences.Chromium.syncEnabled.value = true
 
       return true
     }
@@ -60,10 +71,15 @@ extension BraveSyncAPI {
     deleteDevice(deviceGuid)
   }
 
-  func leaveSyncGroup() {
-    // Remove all observers before leaving the sync chain
-    removeAllObservers()
-
+  /// Method for leaving sync chain
+  /// Removing Observers, clearing local preferences and calling reset chain on brave-core side
+  /// - Parameter preservingObservers: Parameter that decides if observers should be preserved or removed
+  func leaveSyncGroup(preservingObservers: Bool = false) {
+    if !preservingObservers {
+      // Remove all observers before leaving the sync chain
+      removeAllObservers()
+    }
+
     resetSyncChain()
     Preferences.Chromium.syncEnabled.value = false
   }
@@ -96,11 +112,18 @@ extension BraveSyncAPI {
     }
   }
 
-  func addServiceStateObserver(_ observer: @escaping () -> Void) -> AnyObject {
+  /// Method to add observer for SyncService for onStateChanged and onSyncShutdown
+  /// OnStateChanged can be called in various situations like successful initialization - services unavaiable
+  /// sync shutdown - sync errors - sync chain deleted
+  /// - Parameters:
+  ///   - onStateChanged: Callback for sync service state changes
+  ///   - onServiceShutdown: Callback for sync service shutdown
+  /// - Returns: Listener for service
+  func addServiceStateObserver(_ onStateChanged: @escaping () -> Void, onServiceShutdown: @escaping () -> Void = {}) -> AnyObject {
     let serviceStateListener = BraveSyncServiceListener(onRemoved: { [weak self] observer in
       self?.serviceObservers.remove(observer)
     })
-    serviceStateListener.observer = createSyncServiceObserver(observer, onSyncServiceShutdown: {})
+    serviceStateListener.observer = createSyncServiceObserver(onStateChanged, onSyncServiceShutdown: onServiceShutdown)
 
     serviceObservers.add(serviceStateListener)
     return serviceStateListener

Sources/Brave/Frontend/Sync/SyncAddDeviceViewController.swift

@@ -151,7 +151,7 @@ class SyncAddDeviceViewController: SyncViewController {
   override func viewDidAppear(_ animated: Bool) {
     super.viewDidAppear(animated)
 
-    if !syncAPI.isInSyncGroup {
+    if !syncAPI.isInSyncGroup && !syncAPI.isSyncFeatureActive && !syncAPI.isFirstSetupComplete {
       showInitializationError()
     }
   }