Add state restoration for current account in main scene

Tusker/AppDelegate.swift

@@ -65,6 +65,9 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
         }
         
         switch type {
+        case .mainScene:
+            return "main-scene"
+        
         case .showConversation,
              .showTimeline,
              .checkNotifications,

Tusker/Info.plist

@@ -69,6 +69,7 @@
 		<string>$(PRODUCT_BUNDLE_IDENTIFIER).activity.bookmarks</string>
 		<string>$(PRODUCT_BUNDLE_IDENTIFIER).activity.my-profile</string>
 		<string>$(PRODUCT_BUNDLE_IDENTIFIER).activity.show-profile</string>
+		<string>$(PRODUCT_BUNDLE_IDENTIFIER).activity.main-scene</string>
 	</array>
 	<key>UIApplicationSceneManifest</key>
 	<dict>

Tusker/MainSceneDelegate.swift

@@ -15,12 +15,15 @@ class MainSceneDelegate: UIResponder, UIWindowSceneDelegate {
     
     var window: UIWindow?
 
+    private var launchActivity: NSUserActivity?
+    
     func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
-        // Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
-        // If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
-        // This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
         guard let windowScene = scene as? UIWindowScene else { return }
         
+        if let activity = connectionOptions.userActivities.first ?? session.stateRestorationActivity {
+            launchActivity = activity
+        }
+        
         window = UIWindow(windowScene: windowScene)
         
         if let report = AppDelegate.pendingCrashReport {
@@ -91,6 +94,14 @@ class MainSceneDelegate: UIResponder, UIWindowSceneDelegate {
         DraftsManager.save()
     }
     
+    func stateRestorationActivity(for scene: UIScene) -> NSUserActivity? {
+        if let mastodonController =  window?.windowScene?.session.mastodonController {
+            return UserActivityManager.mainSceneActivity(accountID: mastodonController.accountInfo!.id)
+        } else {
+            return nil
+        }
+    }
+    
     func sceneWillEnterForeground(_ scene: UIScene) {
         // Called as the scene transitions from the background to the foreground.
         // Use this method to undo the changes made on entering the background.
@@ -123,7 +134,14 @@ class MainSceneDelegate: UIResponder, UIWindowSceneDelegate {
     func showAppOrOnboardingUI(session: UISceneSession? = nil) {
         let session = session ?? window!.windowScene!.session
         if LocalData.shared.onboardingComplete {
-            let account = LocalData.shared.getMostRecentAccount()!
+            let account: LocalData.UserAccountInfo
+            if let activity = launchActivity,
+               let activityAccount = UserActivityManager.getAccount(from: activity) {
+                account = activityAccount
+            } else {
+                account = LocalData.shared.getMostRecentAccount()!
+            }
+            
             if session.mastodonController == nil {
                 session.mastodonController = MastodonController.getForAccount(account)
             }

Tusker/Shortcuts/UserActivityManager.swift

@@ -37,6 +37,15 @@ class UserActivityManager {
         }
         return LocalData.shared.getAccount(id: id)
     }
+    
+    // MARK: - Main Scene
+    static func mainSceneActivity(accountID: String) -> NSUserActivity {
+        let activity = NSUserActivity(type: .mainScene)
+        activity.userInfo = [
+            "accountID": accountID,
+        ]
+        return activity
+    }
 
     // MARK: - New Post
     static func newPostActivity(mentioning: Account? = nil, accountID: String) -> NSUserActivity {

Tusker/Shortcuts/UserActivityType.swift

@@ -9,6 +9,7 @@
 import Foundation
 
 enum UserActivityType: String {
+    case mainScene = "space.vaccor.Tusker.activity.main-scene"
     case newPost = "space.vaccor.Tusker.activity.new-post"
     case checkNotifications = "space.vaccor.Tusker.activity.check-notifications"
     case showTimeline = "space.vaccor.Tusker.activity.show-timeline"
@@ -22,6 +23,8 @@ enum UserActivityType: String {
 extension UserActivityType {
     var handle: (NSUserActivity) -> Void {
         switch self {
+        case .mainScene:
+            fatalError("cannot handle main scene activity")
         case .newPost:
             return UserActivityManager.handleNewPost
         case .checkNotifications: