Adds support for activating and deactivating apps

iOS 13.3.1 limits free developer accounts to 3 apps and app extensions. As a workaround, we now allow up to 3 “active” apps (apps with installed provisioning profiles), as well as additional “inactivate” apps which don’t have any profiles installed, causing them to not count towards the total. Inactive apps cannot be opened until they are activated.

AltStore/Managing Apps/AppManager.swift

@@ -58,6 +58,8 @@ extension AppManager
         let fetchRequest = InstalledApp.fetchRequest() as NSFetchRequest<InstalledApp>
         fetchRequest.returnsObjectsAsFaults = false
         
+        var activeAppsCount = 0
+        
         do
         {
             let installedApps = try context.fetch(fetchRequest)
@@ -75,19 +77,29 @@ extension AppManager
             
             for app in installedApps
             {
-                let uti = UTTypeCopyDeclaration(app.installedAppUTI as CFString)?.takeRetainedValue() as NSDictionary?
-                
-                if app.bundleIdentifier == StoreApp.altstoreAppID
-                {
+                guard app.bundleIdentifier != StoreApp.altstoreAppID else {
                     self.scheduleExpirationWarningLocalNotification(for: app)
+                    continue
                 }
-                else
+                
+                let uti = UTTypeCopyDeclaration(app.installedAppUTI as CFString)?.takeRetainedValue() as NSDictionary?
+                guard uti != nil || legacySideloadedApps.contains(app.bundleIdentifier) else {
+                    // This UTI is not declared by any apps, which means this app has been deleted by the user.
+                    // This app is also not a legacy sideloaded app, so we can assume it's fine to delete it.
+                    context.delete(app)
+                    continue
+                }
+                
+                if app.isActive
                 {
-                    if uti == nil && !legacySideloadedApps.contains(app.bundleIdentifier)
+                    if let activeAppsLimit = UserDefaults.standard.activeAppsLimit, activeAppsCount >= activeAppsLimit - 1
                     {
-                        // This UTI is not declared by any apps, which means this app has been deleted by the user.
-                        // This app is also not a legacy sideloaded app, so we can assume it's fine to delete it.
-                        context.delete(app)
+                        // We have reached active apps limit (excluding AltStore itself), so mark additional active apps as inactive.
+                        app.isActive = false
+                    }
+                    else
+                    {
+                        activeAppsCount += 1
                     }
                 }
             }
@@ -215,6 +227,42 @@ extension AppManager
         return self.perform(operations, presentingViewController: presentingViewController, group: group)
     }
     
+    func activate(_ installedApp: InstalledApp, presentingViewController: UIViewController?, completionHandler: @escaping (Result<InstalledApp, Error>) -> Void)
+    {
+        let group = self.refresh([installedApp], presentingViewController: presentingViewController)
+        group.completionHandler = { (results) in
+            do
+            {
+                guard let result = results.values.first else { throw OperationError.unknown }
+                
+                let installedApp = try result.get()
+                installedApp.managedObjectContext?.perform {
+                    installedApp.isActive = true
+                    completionHandler(.success(installedApp))
+                }
+            }
+            catch
+            {
+                completionHandler(.failure(error))
+            }
+        }
+    }
+    
+    func deactivate(_ installedApp: InstalledApp, completionHandler: @escaping (Result<InstalledApp, Error>) -> Void)
+    {
+        let context = OperationContext()
+        
+        let findServerOperation = self.findServer(context: context) { _ in }
+        
+        let deactivateAppOperation = DeactivateAppOperation(app: installedApp, context: context)
+        deactivateAppOperation.resultHandler = { (result) in
+            completionHandler(result)
+        }
+        deactivateAppOperation.addDependency(findServerOperation)
+        
+        self.run([deactivateAppOperation], requiresSerialQueue: true)
+    }
+    
     func installationProgress(for app: AppProtocol) -> Progress?
     {
         let progress = self.installationProgress[app.bundleIdentifier]
@@ -468,7 +516,23 @@ private extension AppManager
         /* Refresh */
         let refreshAppOperation = RefreshAppOperation(context: context)
         refreshAppOperation.resultHandler = { (result) in
-            completionHandler(result)
+            switch result
+            {
+            case .success(let installedApp):
+                completionHandler(.success(installedApp))
+                
+            case .failure(ALTServerError.unknownRequest):
+                // Fall back to installation if AltServer doesn't support newer provisioning profile requests.
+                app.managedObjectContext?.perform {
+                    let installProgress = self._install(app, group: group) { (result) in
+                        completionHandler(result)
+                    }
+                    progress.addChild(installProgress, withPendingUnitCount: 40)
+                }
+                
+            case .failure(let error):
+                completionHandler(.failure(error))
+            }
         }
         progress.addChild(refreshAppOperation.progress, withPendingUnitCount: 40)
         refreshAppOperation.addDependency(fetchProvisioningProfilesOperation)