Sync state progress improvements

Reader/ExcerptGenerator.swift

@@ -16,7 +16,7 @@ public struct ExcerptGenerator {
     
     private static let logger = Logger(subsystem: Bundle.main.bundleIdentifier!, category: "ExcerptGenerator")
     
-    static func generateAll(_ fervorController: FervorController) async {
+    static func generateAll(_ fervorController: FervorController, setProgress: @escaping (_ current: Int, _ total: Int) -> Void) async {
         let req = Item.fetchRequest()
         req.predicate = NSPredicate(format: "generatedExcerpt = NO")
         req.sortDescriptors = [NSSortDescriptor(key: "published", ascending: false)]
@@ -31,6 +31,7 @@ public struct ExcerptGenerator {
                     count += 1
                     if count % 50 == 0 {
                         logger.debug("Generated \(count, privacy: .public) excerpts")
+                        setProgress(count, items.count)
                     }
                 }
                 item.generatedExcerpt = true

Reader/FervorController.swift

@@ -66,12 +66,11 @@ actor FervorController {
     }
     
     func syncAll() async throws {
-        guard lastSyncState == .done else {
+        guard lastSyncState.isFinished else {
             return
         }
-        // always return to .done, even if we throw and stop syncing early
-        defer { setSyncState(.done) }
         
+        do {
             setSyncState(.groupsAndFeeds)
             
             logger.info("Syncing groups and feeds")
@@ -87,10 +86,15 @@ actor FervorController {
             try await persistentContainer.syncItems(update, setProgress: { count, total in self.setSyncState(.updateItems(current: count, total: total)) })
             try await persistentContainer.updateLastSyncDate(update.syncTimestamp)
             
-        setSyncState(.excerpts)
+            await ExcerptGenerator.generateAll(self, setProgress: { count, total in self.setSyncState(.excerpts(current: count, total: total)) })
-        await ExcerptGenerator.generateAll(self)
             
             await WidgetHelper.updateWidgetData(fervorController: self)
+            
+            setSyncState(.done)
+        } catch {
+            setSyncState(.error(error))
+            throw error
+        }
     }
     
     @MainActor
@@ -170,11 +174,21 @@ actor FervorController {
 }
 
 extension FervorController {
-    enum SyncState: Equatable {
+    enum SyncState {
         case groupsAndFeeds
         case items
         case updateItems(current: Int, total: Int)
-        case excerpts
+        case excerpts(current: Int, total: Int)
+        case error(Error)
         case done
+        
+        var isFinished: Bool {
+            switch self {
+            case .error(_), .done:
+                return true
+            default:
+                return false
+            }
+        }
     }
 }

Reader/Screens/Home/HomeViewController.swift

@@ -29,13 +29,22 @@ class HomeViewController: UIViewController {
     private var feedResultsController: NSFetchedResultsController<Feed>!
     
     private var lastSyncState = FervorController.SyncState.done
-    private var syncStateView: SyncStateView?
+    // weak so that when it's removed from the superview, this becomes nil
+    private weak var syncStateView: SyncStateView?
     private var cancellables = Set<AnyCancellable>()
     
     init(fervorController: FervorController) {
         self.fervorController = fervorController
         
         super.init(nibName: nil, bundle: nil)
+        
+        fervorController.syncState
+            .buffer(size: 25, prefetch: .byRequest, whenFull: .dropOldest)
+            .receive(on: RunLoop.main)
+            .sink { [unowned self] in
+                self.syncStateChanged($0)
+            }
+            .store(in: &cancellables)
     }
     
     required init?(coder: NSCoder) {
@@ -93,13 +102,6 @@ class HomeViewController: UIViewController {
         feedResultsController = NSFetchedResultsController(fetchRequest: feedReq, managedObjectContext: fervorController.persistentContainer.viewContext, sectionNameKeyPath: nil, cacheName: nil)
         feedResultsController.delegate = self
         try! feedResultsController.performFetch()
-        
-        fervorController.syncState
-            .debounce(for: .milliseconds(250), scheduler: RunLoop.main, options: nil)
-            .sink { [unowned self] in
-                self.syncStateChanged($0)
-            }
-            .store(in: &cancellables)
     }
     
     override func viewWillAppear(_ animated: Bool) {
@@ -150,7 +152,7 @@ class HomeViewController: UIViewController {
     }
     
     private func syncStateChanged(_ newState: FervorController.SyncState) {
-        if newState == .done {
+        if case .done = newState {
             // update unread counts for visible items
             var snapshot = dataSource.snapshot()
             snapshot.reconfigureItems(snapshot.itemIdentifiers)
@@ -162,7 +164,7 @@ class HomeViewController: UIViewController {
             }
         }
         
-        func updateView(_ syncStateView: SyncStateView) {
+        func updateView(_ syncStateView: SyncStateView, isFirstUpdate: Bool) {
             switch newState {
             case .groupsAndFeeds:
                 syncStateView.label.text = "Syncing groups and feeds"
@@ -170,21 +172,24 @@ class HomeViewController: UIViewController {
                 syncStateView.label.text = "Syncing items"
             case .updateItems(current: let current, total: let total):
                 syncStateView.label.text = "Updating \(current + 1) of \(total) item\(total == 1 ? "" : "s")"
-            case .excerpts:
+            case .excerpts(current: let current, total: let total):
-                syncStateView.label.text = "Generating excerpts"
+                syncStateView.label.text = "Generating \(current) of \(total) excerpt\(total == 1 ? "" : "s")"
+            case .error(let error):
+                syncStateView.label.text = "Error syncing"
+                syncStateView.subtitleLabel.isHidden = false
+                syncStateView.subtitleLabel.text = error.localizedDescription
+                
+                syncStateView.removeAfterDelay(delay: isFirstUpdate ? 2 : 1)
+                
             case .done:
                 syncStateView.label.text = "Done syncing"
 
-                UIView.animate(withDuration: 0.25, delay: 1, options: .curveEaseIn) {
+                syncStateView.removeAfterDelay(delay: isFirstUpdate ? 2 : 1)
-                    syncStateView.transform = CGAffineTransform(translationX: 0, y: syncStateView.bounds.height)
-                } completion: { _ in
-                    syncStateView.removeFromSuperview()
-                }
             }
         }
         
         if let syncStateView = self.syncStateView {
-            updateView(syncStateView)
+            updateView(syncStateView, isFirstUpdate: false)
         } else {
             let syncStateView = SyncStateView()
             self.syncStateView = syncStateView
@@ -196,13 +201,13 @@ class HomeViewController: UIViewController {
                 syncStateView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
             ])
             
+            updateView(syncStateView, isFirstUpdate: true)
+            
             view.layoutIfNeeded()
             syncStateView.transform = CGAffineTransform(translationX: 0, y: syncStateView.bounds.height)
            
             UIView.animate(withDuration: 0.25, delay: 0, options: .curveEaseOut) {
                 syncStateView.transform = .identity
-            } completion: { _ in
-                updateView(syncStateView)
             }
         }
     }
@@ -335,6 +340,7 @@ extension HomeViewController: LoginViewControllerDelegate {
 
 private class SyncStateView: UIView {
     let label = UILabel()
+    let subtitleLabel = UILabel()
     
     init() {
         super.init(frame: .zero)
@@ -344,8 +350,20 @@ private class SyncStateView: UIView {
         blurView.translatesAutoresizingMaskIntoConstraints = false
         addSubview(blurView)
         
-        label.translatesAutoresizingMaskIntoConstraints = false
+        label.font = .preferredFont(forTextStyle: .callout)
-        addSubview(label)
+        subtitleLabel.font = .preferredFont(forTextStyle: .caption1)
+        subtitleLabel.isHidden = true
+        subtitleLabel.numberOfLines = 2
+        
+        let stack = UIStackView(arrangedSubviews: [
+            label,
+            subtitleLabel,
+        ])
+        stack.translatesAutoresizingMaskIntoConstraints = false
+        stack.axis = .vertical
+        stack.alignment = .center
+        stack.spacing = 4
+        addSubview(stack)
         
         NSLayoutConstraint.activate([
             blurView.leadingAnchor.constraint(equalTo: leadingAnchor),
@@ -353,10 +371,12 @@ private class SyncStateView: UIView {
             blurView.topAnchor.constraint(equalTo: topAnchor),
             blurView.bottomAnchor.constraint(equalTo: bottomAnchor),
             
-            label.centerXAnchor.constraint(equalTo: safeAreaLayoutGuide.centerXAnchor),
+            stack.centerXAnchor.constraint(equalTo: safeAreaLayoutGuide.centerXAnchor),
-            label.centerYAnchor.constraint(equalTo: safeAreaLayoutGuide.centerYAnchor),
+            stack.topAnchor.constraint(greaterThanOrEqualToSystemSpacingBelow: safeAreaLayoutGuide.topAnchor, multiplier: 1),
+            stack.bottomAnchor.constraint(lessThanOrEqualToSystemSpacingBelow: safeAreaLayoutGuide.bottomAnchor, multiplier: 1),
+            stack.centerYAnchor.constraint(equalTo: safeAreaLayoutGuide.centerYAnchor),
             
-            safeAreaLayoutGuide.heightAnchor.constraint(equalToConstant: 50),
+            topAnchor.constraint(lessThanOrEqualTo: safeAreaLayoutGuide.bottomAnchor, constant: -50),
         ])
         
         layer.shadowColor = UIColor.black.cgColor
@@ -367,4 +387,15 @@ private class SyncStateView: UIView {
     required init?(coder: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }
+    
+    func removeAfterDelay(delay: Int) {
+        // can't use UIView.animate's delay b/c it may clash with the appearance animation
+        DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(delay)) {
+            UIView.animate(withDuration: 0.25, delay: 0, options: .curveEaseIn) {
+                self.transform = CGAffineTransform(translationX: 0, y: self.bounds.height)
+            } completion: { _ in
+                self.removeFromSuperview()
+            }
+        }
+    }
 }