[Universal Links] Do not enter undetermined state if the user does not have access to the passed blog Id

WooCommerce/Classes/Authentication/Epilogue/SwitchStoreUseCase.swift

@@ -1,5 +1,6 @@
 import UIKit
 import Yosemite
+import protocol Storage.StorageManagerType
 
 protocol SwitchStoreUseCaseProtocol {
     func switchStore(with storeID: Int64, onCompletion: @escaping (Bool) -> Void)
@@ -10,9 +11,19 @@ protocol SwitchStoreUseCaseProtocol {
 final class SwitchStoreUseCase: SwitchStoreUseCaseProtocol {
 
     private let stores: StoresManager
+    private let storageManager: StorageManagerType
 
-    init(stores: StoresManager) {
+    private lazy var resultsController: ResultsController<StorageSite> = {
+        return ResultsController(storageManager: storageManager, sortedBy: [])
+    }()
+
+    private var wooCommerceSites: [Site] {
+        resultsController.fetchedObjects.filter { $0.isWooCommerceActive == true }
+    }
+
+    init(stores: StoresManager, storageManager: StorageManagerType = ServiceLocator.storageManager) {
         self.stores = stores
+        self.storageManager = storageManager
     }
 
     /// The async version of `switchStore` that wraps the completion block version.
@@ -28,6 +39,25 @@ final class SwitchStoreUseCase: SwitchStoreUseCaseProtocol {
         }
     }
 
+    /// Switches the to store with the given id if it was previously synced and stored.
+    /// This is done to check whether the user has access to that store, avoiding undetermined states if we log out
+    /// from the current one and try to switch to a store they don't have access to.
+    ///
+    /// - Parameter storeID: target store ID.
+    /// - Returns: a boolean that indicates whether the site was changed.
+    ///
+    func switchToStoreIfSiteIsStored(with storeID: Int64, onCompletion: @escaping (Bool) -> Void) {
+        self.refreshStoredSites()
+
+        let siteWasStored = self.wooCommerceSites.first(where: { $0.siteID == storeID }) != nil
+
+        guard siteWasStored else {
+            return onCompletion(false)
+        }
+
+        switchStore(with: storeID, onCompletion: onCompletion)
+    }
+
     /// A static method which allows easily to switch store. The boolean argument in `onCompletion` indicates that the site was changed.
     /// When `onCompletion` is called, the selected site ID is updated while `Site` might still not be available if the site does not exist in storage yet
     /// (e.g. a newly connected site).
@@ -111,4 +141,8 @@ final class SwitchStoreUseCase: SwitchStoreUseCaseProtocol {
 
         AppDelegate.shared.authenticatorWasDismissed()
     }
+
+    private func refreshStoredSites() {
+        try? resultsController.performFetch()
+    }
 }

WooCommerce/Classes/ViewRelated/MainTabBarController.swift

@@ -337,9 +337,10 @@ extension MainTabBarController {
             }
             let siteID = Int64(note.meta.identifier(forKey: .site) ?? Int.min)
 
-            switchToStore(with: siteID, onCompletion: {
-                presentNotificationDetails(for: note)
-
+            switchToStore(with: siteID, onCompletion: { siteChanged in
+                if siteChanged {
+                    presentNotificationDetails(for: note)
+                }
             })
         }
         ServiceLocator.stores.dispatch(action)
@@ -368,14 +369,16 @@ extension MainTabBarController {
                                                                               "already_read": note.read ])
     }
 
-    private static func switchToStore(with siteID: Int64, onCompletion: @escaping () -> Void) {
-        SwitchStoreUseCase(stores: ServiceLocator.stores).switchStore(with: siteID) { siteChanged in
-            if siteChanged {
-                let presenter = SwitchStoreNoticePresenter(siteID: siteID)
-                presenter.presentStoreSwitchedNoticeWhenSiteIsAvailable(configuration: .switchingStores)
+    private static func switchToStore(with siteID: Int64, onCompletion: @escaping (Bool) -> Void) {
+        SwitchStoreUseCase(stores: ServiceLocator.stores).switchToStoreIfSiteIsStored(with: siteID) { siteChanged in
+            guard siteChanged else {
+                return onCompletion(false)
             }
 
-            onCompletion()
+            let presenter = SwitchStoreNoticePresenter(siteID: siteID)
+            presenter.presentStoreSwitchedNoticeWhenSiteIsAvailable(configuration: .switchingStores)
+
+            onCompletion(true)
         }
     }
 
@@ -392,8 +395,11 @@ extension MainTabBarController {
     }
 
     static func navigateToOrderDetails(with orderID: Int64, siteID: Int64) {
-        switchToStore(with: siteID, onCompletion: {
+        switchToStore(with: siteID, onCompletion: { siteChanged in
             switchToOrdersTab {
+                guard siteChanged else {
+                    return
+                }
                 // We give some time to the orders tab transition to finish, otherwise it might prevent the second navigation from happening
                 DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) {
                     presentDetails(for: orderID, siteID: siteID)