Use async/await for conversation loading

Tusker/CoreData/MastodonCachePersistentStore.swift

@@ -88,6 +88,16 @@ class MastodonCachePersistentStore: NSPersistentContainer {
         }
     }
     
+    @MainActor
+    func addOrUpdateOnViewContext(status: Status) -> StatusMO {
+        let statusMO = self.upsert(status: status, context: viewContext)
+        if viewContext.hasChanges {
+            try! viewContext.save()
+        }
+        statusSubject.send(status.id)
+        return statusMO
+    }
+
     func addAll(statuses: [Status], completion: (() -> Void)? = nil) {
         backgroundContext.perform {
             statuses.forEach { self.upsert(status: $0, context: self.backgroundContext) }
@@ -99,6 +109,14 @@ class MastodonCachePersistentStore: NSPersistentContainer {
         }
     }
     
+    func addAll(statuses: [Status]) async {
+        return await withCheckedContinuation { continuation in
+            addAll(statuses: statuses) {
+                continuation.resume()
+            }
+        }
+    }
+
     func account(for id: String, in context: NSManagedObjectContext? = nil) -> AccountMO? {
         let context = context ?? viewContext
         let request: NSFetchRequest<AccountMO> = AccountMO.fetchRequest()

Tusker/Screens/Conversation/ConversationTableViewController.swift

@@ -131,41 +131,38 @@ class ConversationTableViewController: EnhancedTableViewController {
         }
         navigationItem.rightBarButtonItem = visibilityBarButtonItem
         
-        loadMainStatus()
+        Task {
+            await loadMainStatus()
+        }
     }
     
-    private func loadMainStatus() {
+    @MainActor
+    private func loadMainStatus() async {
         guard loadingState == .unloaded else { return }
         
         if let mainStatus = mastodonController.persistentContainer.status(for: mainStatusID) {
-            self.mainStatusLoaded(mainStatus)
+            await mainStatusLoaded(mainStatus)
         } else {
             loadingState = .loadingMain
-            let request = Client.getStatus(id: mainStatusID)
+            let req = Client.getStatus(id: mainStatusID)
-            mastodonController.run(request) { (response) in
+            do {
-                switch response {
+                let (status, _) = try await mastodonController.run(req)
-                case let .success(status, _):
+                let statusMO = mastodonController.persistentContainer.addOrUpdateOnViewContext(status: status)
-                    let viewContext = self.mastodonController.persistentContainer.viewContext
+                await mainStatusLoaded(statusMO)
-                    self.mastodonController.persistentContainer.addOrUpdate(status: status, context: viewContext) { (statusMO) in
+            } catch {
-                        self.mainStatusLoaded(statusMO)
+                let error = error as! Client.Error
-                    }
+                loadingState = .unloaded
-                    
+                let config = ToastConfiguration(from: error, with: "Error Loading Status", in: self) { [weak self] toast in
-                case let .failure(error):
-                    DispatchQueue.main.async {
-                        self.loadingState = .unloaded
-                        
-                        let config = ToastConfiguration(from: error, with: "Error Loading Status", in: self) { [weak self] (toast) in
                     toast.dismissToast(animated: true)
-                            self?.loadMainStatus()
+                    await self?.loadMainStatus()
-                        }
-                        self.showToast(configuration: config, animated: true)
-                    }
                 }
+                showToast(configuration: config, animated: true)
+                return
             }
         }
     }
     
-    private func mainStatusLoaded(_ mainStatus: StatusMO) {
+    private func mainStatusLoaded(_ mainStatus: StatusMO) async {
         let mainStatusItem = Item.status(id: mainStatusID, state: mainStatusState)
         
         var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
@@ -175,10 +172,11 @@ class ConversationTableViewController: EnhancedTableViewController {
 
         loadingState = .loadedMain
 
-        loadContext(for: mainStatus)
+        await loadContext(for: mainStatus)
     }
     
-    private func loadContext(for mainStatus: StatusMO) {
+    @MainActor
+    private func loadContext(for mainStatus: StatusMO) async {
         guard loadingState == .loadedMain else { return }
         
         loadingState = .loadingContext
@@ -188,32 +186,26 @@ class ConversationTableViewController: EnhancedTableViewController {
         
         // todo: it would be nice to cache these contexts
         let request = Status.getContext(mainStatusID)
-        mastodonController.run(request) { response in
+        do {
-            switch response {
+            let (context, _) = try await mastodonController.run(request)
-            case let .success(context, _):
             let parentIDs = self.getDirectParents(inReplyTo: mainStatusInReplyToID, from: context.ancestors)
             let parentStatuses = context.ancestors.filter { parentIDs.contains($0.id) }
             
             // todo: should this really be blindly adding all the descendants?
-                self.mastodonController.persistentContainer.addAll(statuses: parentStatuses + context.descendants) {
+            await mastodonController.persistentContainer.addAll(statuses: parentStatuses + context.descendants)
-                    DispatchQueue.main.async {
             self.contextLoaded(mainStatus: mainStatus, context: context, parentIDs: parentIDs)
-                    }
-                }
             
-            case let .failure(error):
+        } catch {
-                DispatchQueue.main.async {
+            let error = error as! Client.Error
             self.loadingState = .loadedMain
                 
             let config = ToastConfiguration(from: error, with: "Error Loading Content", in: self) { [weak self] (toast) in
                 toast.dismissToast(animated: true)
-                        self?.loadContext(for: mainStatus)
+                await self?.loadContext(for: mainStatus)
             }
             self.showToast(configuration: config, animated: true)
         }
     }
-        }
-    }
     
     private func contextLoaded(mainStatus: StatusMO, context: ConversationContext, parentIDs: [String]) {
         let mainStatusItem = Item.status(id: mainStatusID, state: mainStatusState)

Tusker/Views/Toast/ToastConfiguration.swift

@@ -57,6 +57,14 @@ extension ToastConfiguration {
             viewController.present(reporter, animated: true)
         }
     }
+    
+    init(from error: Client.Error, with title: String, in viewController: UIViewController, retryAction: @escaping @MainActor (ToastView) async -> Void) {
+        self.init(from: error, with: title, in: viewController) { toast in
+            Task {
+                await retryAction(toast)
+            }
+        }
+    }
 }
 
 fileprivate extension Client.Error {