Supports adding/removing source from SourceDetailViewController

AltStore/Managing Apps/AppManager.swift

@@ -332,6 +332,61 @@ extension AppManager
 
 extension AppManager
 {
+    func fetchSource(sourceURL: URL, managedObjectContext: NSManagedObjectContext = DatabaseManager.shared.persistentContainer.newBackgroundContext()) async throws -> Source
+    {
+        try await withCheckedThrowingContinuation { continuation in
+            self.fetchSource(sourceURL: sourceURL, managedObjectContext: managedObjectContext) { result in
+                continuation.resume(with: result)
+            }
+        }
+    }
+    
+    func add(@AsyncManaged _ source: Source, message: String? = nil, presentingViewController: UIViewController) async throws
+    {
+        let (sourceName, sourceURL) = await $source.get { ($0.name, $0.sourceURL) }
+        
+        let context = DatabaseManager.shared.persistentContainer.newBackgroundContext()
+        async let fetchedSource = try await self.fetchSource(sourceURL: sourceURL, managedObjectContext: context) // Fetch source async while showing alert.
+
+        let title = String(format: NSLocalizedString("Would you like to add the source “%@”?", comment: ""), sourceName)
+        let message = message ?? NSLocalizedString("Make sure to only add sources that you trust.", comment: "")
+        let action = await UIAlertAction(title: NSLocalizedString("Add Source", comment: ""), style: .default)
+        try await presentingViewController.presentConfirmationAlert(title: title, message: message, primaryAction: action)
+
+        // Wait for fetch to finish before saving context.
+        _ = try await fetchedSource
+        
+        try await context.performAsync {
+            try context.save()
+        }
+    }
+    
+    func remove(@AsyncManaged _ source: Source, presentingViewController: UIViewController) async throws
+    {
+        let (sourceName, sourceID) = await $source.get { ($0.name, $0.identifier) }
+        guard sourceID != Source.altStoreIdentifier else {
+            throw OperationError.forbidden(failureReason: NSLocalizedString("The default AltStore source cannot be removed.", comment: ""))
+        }
+        
+        let title = String(format: NSLocalizedString("Are you sure you want to remove the source “%@”?", comment: ""), sourceName)
+        let message = NSLocalizedString("Any apps you've installed from this source will remain, but they'll no longer receive any app updates.", comment: "")
+        let action = await UIAlertAction(title: NSLocalizedString("Remove Source", comment: ""), style: .destructive)
+        try await presentingViewController.presentConfirmationAlert(title: title, message: message, primaryAction: action)
+        
+        let context = DatabaseManager.shared.persistentContainer.newBackgroundContext()
+        try await context.performAsync {
+            let predicate = NSPredicate(format: "%K == %@", #keyPath(Source.identifier), sourceID)
+            guard let source = Source.first(satisfying: predicate, in: context) else { return } // Doesn't exist == success.
+            
+            context.delete(source)
+            try context.save()
+        }
+    }
+}
+
+extension AppManager
+{
+    @available(*, renamed: "fetchSource(sourceURL:managedObjectContext:)")
     func fetchSource(sourceURL: URL,
                      managedObjectContext: NSManagedObjectContext = DatabaseManager.shared.persistentContainer.newBackgroundContext(),
                      dependencies: [Foundation.Operation] = [],

AltStore/Operations/OperationError.swift

@@ -30,6 +30,7 @@ extension OperationError
         case noSources
         case openAppFailed
         case missingAppGroup
+        case forbidden
         
         /* Connection */
         case serverNotFound = 1200
@@ -61,6 +62,10 @@ extension OperationError
     static func maximumAppIDLimitReached(appName: String, requiredAppIDs: Int, availableAppIDs: Int, expirationDate: Date) -> OperationError {
         OperationError(code: .maximumAppIDLimitReached, appName: appName, requiredAppIDs: requiredAppIDs, availableAppIDs: availableAppIDs, expirationDate: expirationDate)
     }
+    
+    static func forbidden(failureReason: String? = nil, file: String = #fileID, line: UInt = #line) -> OperationError {
+        OperationError(code: .forbidden, failureReason: failureReason, sourceFile: file, sourceLine: line)
+    }
 }
 
 struct OperationError: ALTLocalizedError
@@ -112,6 +117,9 @@ struct OperationError: ALTLocalizedError
         case .maximumAppIDLimitReached: return NSLocalizedString("You cannot register more than 10 App IDs within a 7 day period.", comment: "")
         case .noSources: return NSLocalizedString("There are no AltStore sources.", comment: "")
         case .missingAppGroup: return NSLocalizedString("AltStore's shared app group could not be accessed.", comment: "")
+        case .forbidden:
+            guard let failureReason = self._failureReason else { return NSLocalizedString("The operation is forbidden.", comment: "") }
+            return failureReason
 
         case .appNotFound:
             let appName = self.appName ?? NSLocalizedString("The app", comment: "")

AltStore/Sources/SourceDetailContentViewController.swift

@@ -234,6 +234,7 @@ private extension SourceDetailContentViewController
             cell.bannerView.button.setTitle(buttonTitle.uppercased(), for: .normal)
             cell.bannerView.button.accessibilityLabel = String(format: NSLocalizedString("Download %@", comment: ""), storeApp.name)
             cell.bannerView.button.accessibilityValue = buttonTitle
+            cell.bannerView.button.addTarget(self, action: #selector(SourceDetailContentViewController.addSourceThenDownloadApp(_:)), for: .primaryActionTriggered)
             
             let progress = AppManager.shared.installationProgress(for: storeApp)
             cell.bannerView.button.progress = progress
@@ -397,6 +398,68 @@ extension SourceDetailContentViewController
     }
 }
 
+private extension SourceDetailContentViewController
+{
+    @objc func addSourceThenDownloadApp(_ sender: UIButton)
+    {
+        let point = self.collectionView.convert(sender.center, from: sender.superview)
+        guard let indexPath = self.collectionView.indexPathForItem(at: point) else { return }
+        
+        sender.isIndicatingActivity = true
+        
+        let storeApp = self.dataSource.item(at: indexPath) as! StoreApp
+        
+        Task<Void, Never> {
+            do
+            {
+                let isAdded = try await self.source.isAdded
+                if !isAdded
+                {
+                    let message = String(format: NSLocalizedString("You must add this source before you can install apps from it.\n\n“%@” will begin downloading once it has been added.", comment: ""), storeApp.name)
+                    try await AppManager.shared.add(self.source, message: message, presentingViewController: self)
+                }
+                
+                do
+                {
+                    try await self.downloadApp(storeApp)
+                }
+                catch OperationError.cancelled {}
+                catch
+                {
+                    let toastView = ToastView(error: error)
+                    toastView.opensErrorLog = true
+                    toastView.show(in: self)
+                }
+            }
+            catch is CancellationError {}
+            catch
+            {
+                await self.presentAlert(title: NSLocalizedString("Unable to Add Source", comment: ""), message: error.localizedDescription)
+            }
+            
+            sender.isIndicatingActivity = false
+            self.collectionView.reloadSections([Section.featuredApps.rawValue])
+        }
+    }
+    
+    func downloadApp(_ storeApp: StoreApp) async throws
+    {
+        try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, Error>) in
+            AppManager.shared.install(storeApp, presentingViewController: self) { result in
+                continuation.resume(with: result.map { _ in })
+            }
+            
+            guard let index = self.appsDataSource.items.firstIndex(of: storeApp) else {
+                self.collectionView.reloadSections([Section.featuredApps.rawValue])
+                return
+            }
+            
+            let indexPath = IndexPath(item: index, section: Section.featuredApps.rawValue)
+            self.collectionView.reloadItems(at: [indexPath])
+        }
+    }
+}
+
 extension SourceDetailContentViewController: ScrollableContentViewController
 {
     var scrollView: UIScrollView { self.collectionView }

AltStore/Sources/SourceDetailViewController.swift

@@ -8,23 +8,90 @@
 
 import UIKit
 import SafariServices
+import Combine
 
 import AltStoreCore
 import Roxas
 
 import Nuke
 
+extension SourceDetailViewController
+{
+    private class ViewModel: ObservableObject
+    {
+        let source: Source
+        
+        @Published
+        var isSourceAdded: Bool? = nil
+        
+        @Published
+        var isAddingSource: Bool = false
+        
+        init(source: Source)
+        {
+            self.source = source
+            
+            Task<Void, Never> {
+                do
+                {
+                    self.isSourceAdded = try await self.source.isAdded
+                }
+                catch
+                {
+                    print("[ALTLog] Failed to check if source is added.", error)
+                }
+            }
+        }
+    }
+}
+
 class SourceDetailViewController: HeaderContentViewController<SourceHeaderView, SourceDetailContentViewController>
 {
     @Managed private(set) var source: Source
     
+    private let viewModel: ViewModel
+    
     private var addButton: VibrantButton!
     
     private var previousBounds: CGRect?
+    private var cancellable: AnyCancellable?
     
     init?(source: Source, coder: NSCoder)
     {
+        let isolatedContext: NSManagedObjectContext
+        
+        if source.managedObjectContext == DatabaseManager.shared.viewContext
+        {
+            do
+            {
+                // Source is persisted to disk, so we can create a new view context
+                // that's pinned to current query generation to ensure information
+                // doesn't disappear out from under us if we remove (delete) the source.
+                let context = DatabaseManager.shared.persistentContainer.newViewContext(withParent: nil)
+                try context.setQueryGenerationFrom(.current)
+                isolatedContext = context
+            }
+            catch
+            {
+                print("[ATLog] Failed to set query generation for context.", error)
+                isolatedContext = DatabaseManager.shared.persistentContainer.newViewContext(withParent: source.managedObjectContext)
+            }
+        }
+        else
+        {
+            // Source is not persisted to disk, so create child view context with source's managedObjectContext as parent.
+            // This also maintains a strong reference to source.managedObjectContext, which may be necessary.
+            isolatedContext = DatabaseManager.shared.persistentContainer.newViewContext(withParent: source.managedObjectContext)
+        }
+               
+        // Ignore changes from other contexts so we can delete source without UI automatically updating.
+        isolatedContext.automaticallyMergesChangesFromParent = false
+        
+        let source = isolatedContext.object(with: source.objectID) as! Source
         self.source = source
+        
+        self.viewModel = ViewModel(source: source)
+        
         super.init(coder: coder)
         
         self.title = source.name
@@ -41,15 +108,18 @@ class SourceDetailViewController: HeaderContentViewController<SourceHeaderView,
         super.viewDidLoad()
         
         self.addButton = VibrantButton(type: .system)
-        self.addButton.title = NSLocalizedString("ADD", comment: "")
         self.addButton.contentInsets = PillButton.contentInsets
+        self.addButton.addTarget(self, action: #selector(SourceDetailViewController.addSource), for: .primaryActionTriggered)
         self.addButton.sizeToFit()
         self.view.addSubview(self.addButton)
         
+        self.navigationBarButton.addTarget(self, action: #selector(SourceDetailViewController.addSource), for: .primaryActionTriggered)
+        
         Nuke.loadImage(with: self.source.effectiveIconURL, into: self.navigationBarIconView)
         Nuke.loadImage(with: self.source.effectiveHeaderImageURL, into: self.backgroundImageView)
         
         self.update()
+        self.preparePipeline()
     }
     
     override func viewDidLayoutSubviews()
@@ -106,10 +176,87 @@ class SourceDetailViewController: HeaderContentViewController<SourceHeaderView,
             self.addButton.isHidden = true
             self.navigationBarButton.isHidden = true
         }
+        else
+        {
+            // Update isIndicatingActivity first to ensure later updates are applied correctly.
+            self.addButton.isIndicatingActivity = self.viewModel.isAddingSource
+            self.navigationBarButton.isIndicatingActivity = self.viewModel.isAddingSource
+            
+            let title: String
+            
+            switch self.viewModel.isSourceAdded
+            {
+            case true?:
+                title = NSLocalizedString("REMOVE", comment: "")
+                self.navigationBarButton.tintColor = .refreshRed
+                
+                self.addButton.isHidden = false
+                self.navigationBarButton.isHidden = false
+                
+            case false?:
+                title = NSLocalizedString("ADD", comment: "")
+                self.navigationBarButton.tintColor = self.source.effectiveTintColor ?? .altPrimary
+                
+                self.addButton.isHidden = false
+                self.navigationBarButton.isHidden = false
+                
+            case nil:
+                title = ""
+                
+                self.addButton.isHidden = true
+                self.navigationBarButton.isHidden = true
+            }
+            
+            if self.addButton.title != title
+            {
+                self.addButton.title = title
+                self.navigationBarButton.setTitle(title, for: .normal)
+            }
+            
+            self.view.setNeedsLayout()
+        }
     }
     
     //MARK: Actions
     
+    @objc private func addSource()
+    {
+        self.viewModel.isAddingSource = true
+        
+        Task<Void, Never> { /* @MainActor in */ // Already on MainActor, even though this function wasn't called from async context.
+            var isSourceAdded: Bool?
+            var errorTitle = NSLocalizedString("Unable to Add Source", comment: "")
+            
+            do
+            {
+                let isAdded = try await self.source.isAdded
+                if isAdded
+                {
+                    errorTitle = NSLocalizedString("Unable to Remove Source", comment: "")
+                    try await AppManager.shared.remove(self.source, presentingViewController: self)
+                }
+                else
+                {
+                    try await AppManager.shared.add(self.source, presentingViewController: self)
+                }
+               
+                isSourceAdded = try await self.source.isAdded
+            }
+            catch is CancellationError {}
+            catch
+            {
+                await self.presentAlert(title: errorTitle, message: error.localizedDescription)
+            }
+            
+            self.viewModel.isAddingSource = false
+            
+            if let isSourceAdded
+            {
+                self.viewModel.isSourceAdded = isSourceAdded
+            }
+        }
+    }
+    
     @objc private func showWebsite()
     {
         guard let websiteURL = self.source.websiteURL else { return }
@@ -119,3 +266,16 @@ class SourceDetailViewController: HeaderContentViewController<SourceHeaderView,
         self.present(safariViewController, animated: true, completion: nil)
     }
 }
+
+private extension SourceDetailViewController
+{
+    func preparePipeline()
+    {
+        self.cancellable = Publishers
+            .CombineLatest(self.viewModel.$isSourceAdded, self.viewModel.$isAddingSource)
+            .receive(on: RunLoop.main)
+            .sink { [weak self] _ in
+                self?.update()
+            }
+    }
+}