[AltStore] Checks for updates in background

AltStore/AppDelegate.swift

@@ -207,7 +207,34 @@ extension AppDelegate
                     let apps = try result.get()
                     
                     guard let context = apps.first?.managedObjectContext else { return }
+                    
+                    let updatesFetchRequest = InstalledApp.updatesFetchRequest()
+                    updatesFetchRequest.includesPendingChanges = true
+                    
+                    let previousUpdatesFetchRequest = InstalledApp.updatesFetchRequest()
+                    previousUpdatesFetchRequest.includesPendingChanges = false
+                    
+                    let previousUpdates = try context.fetch(previousUpdatesFetchRequest)
+                    
                     try context.save()
+                    
+                    let updates = try context.fetch(updatesFetchRequest)
+                    
+                    for update in updates
+                    {
+                        guard !previousUpdates.contains(where: { $0.app.identifier == update.app.identifier }) else { continue }
+                        
+                        let content = UNMutableNotificationContent()
+                        content.title = NSLocalizedString("New Update Available", comment: "")
+                        content.body = String(format: NSLocalizedString("%@ %@ is now available for download.", comment: ""), update.app.name, update.app.version)
+                        
+                        let request = UNNotificationRequest(identifier: UUID().uuidString, content: content, trigger: nil)
+                        UNUserNotificationCenter.current().add(request)
+                    }
+                    
+                    DispatchQueue.main.async {
+                        UIApplication.shared.applicationIconBadgeNumber = updates.count
+                    }
                 }
                 catch
                 {

AltStore/Managing Apps/AppManager.swift

@@ -311,7 +311,7 @@ private extension AppManager
                 context.group.results[context.appIdentifier] = .success(installedApp)
                 
                 // Save after each installation.
-                installedApp.managedObjectContext?.perform {
+                installedApp.managedObjectContext?.performAndWait {
                     do { try installedApp.managedObjectContext?.save() }
                     catch { print("Error saving installed app.", error) }
                 }

AltStore/Model/InstalledApp.swift

@@ -49,6 +49,13 @@ extension InstalledApp
         return NSFetchRequest<InstalledApp>(entityName: "InstalledApp")
     }
     
+    class func updatesFetchRequest() -> NSFetchRequest<InstalledApp>
+    {
+        let fetchRequest = InstalledApp.fetchRequest() as NSFetchRequest<InstalledApp>
+        fetchRequest.predicate = NSPredicate(format: "%K != %K", #keyPath(InstalledApp.version), #keyPath(InstalledApp.app.version))
+        return fetchRequest
+    }
+    
     class func fetchAltStore(in context: NSManagedObjectContext) -> InstalledApp?
     {
         let predicate = NSPredicate(format: "%K == %@", #keyPath(InstalledApp.app.identifier), App.altstoreAppID)

AltStore/My Apps/MyAppsViewController.swift

@@ -104,8 +104,7 @@ private extension MyAppsViewController
     
     func makeUpdatesDataSource() -> RSTFetchedResultsCollectionViewPrefetchingDataSource<InstalledApp, UIImage>
     {
-        let fetchRequest = InstalledApp.fetchRequest() as NSFetchRequest<InstalledApp>
+        let fetchRequest = InstalledApp.updatesFetchRequest()
-        fetchRequest.predicate = NSPredicate(format: "%K != %K", #keyPath(InstalledApp.version), #keyPath(InstalledApp.app.version))
         fetchRequest.sortDescriptors = [NSSortDescriptor(keyPath: \InstalledApp.app?.versionDate, ascending: true),
                                         NSSortDescriptor(keyPath: \InstalledApp.app?.name, ascending: true)]
         fetchRequest.returnsObjectsAsFaults = false
@@ -226,10 +225,12 @@ private extension MyAppsViewController
         if self.updatesDataSource.itemCount > 0
         {
             self.navigationController?.tabBarItem.badgeValue = String(describing: self.updatesDataSource.itemCount)
+            UIApplication.shared.applicationIconBadgeNumber = Int(self.updatesDataSource.itemCount)
         }
         else
         {
             self.navigationController?.tabBarItem.badgeValue = nil
+            UIApplication.shared.applicationIconBadgeNumber = 0
         }
     }