Show better message when opening conv for deleted status

Also split conversation loading out into separate view controller

Tusker.xcodeproj/project.pbxproj

@@ -150,6 +150,8 @@
 		D65B4B58297203A700DABDFB /* ReportSelectRulesView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B4B57297203A700DABDFB /* ReportSelectRulesView.swift */; };
 		D65B4B5A29720AB000DABDFB /* ReportStatusView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B4B5929720AB000DABDFB /* ReportStatusView.swift */; };
 		D65B4B5E2973040D00DABDFB /* ReportAddStatusView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B4B5D2973040D00DABDFB /* ReportAddStatusView.swift */; };
+		D65B4B6229771A3F00DABDFB /* FetchStatusService.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B4B6129771A3F00DABDFB /* FetchStatusService.swift */; };
+		D65B4B6429771EFF00DABDFB /* ConversationViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B4B6329771EFF00DABDFB /* ConversationViewController.swift */; };
 		D65C6BF525478A9C00A6E89C /* BackgroundableViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65C6BF425478A9C00A6E89C /* BackgroundableViewController.swift */; };
 		D65F613423AEAB6600F3CFD3 /* OnboardingTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65F613323AEAB6600F3CFD3 /* OnboardingTests.swift */; };
 		D6620ACE2511A0ED00312CA0 /* StatusStateResolver.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6620ACD2511A0ED00312CA0 /* StatusStateResolver.swift */; };
@@ -537,6 +539,8 @@
 		D65B4B57297203A700DABDFB /* ReportSelectRulesView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ReportSelectRulesView.swift; sourceTree = "<group>"; };
 		D65B4B5929720AB000DABDFB /* ReportStatusView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ReportStatusView.swift; sourceTree = "<group>"; };
 		D65B4B5D2973040D00DABDFB /* ReportAddStatusView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ReportAddStatusView.swift; sourceTree = "<group>"; };
+		D65B4B6129771A3F00DABDFB /* FetchStatusService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FetchStatusService.swift; sourceTree = "<group>"; };
+		D65B4B6329771EFF00DABDFB /* ConversationViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ConversationViewController.swift; sourceTree = "<group>"; };
 		D65C6BF425478A9C00A6E89C /* BackgroundableViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BackgroundableViewController.swift; sourceTree = "<group>"; };
 		D65F612D23AE990C00F3CFD3 /* Embassy.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = Embassy.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		D65F613023AE99E000F3CFD3 /* Ambassador.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = Ambassador.framework; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -1033,6 +1037,7 @@
 		D641C785213DD83B004B4513 /* Conversation */ = {
 			isa = PBXGroup;
 			children = (
+				D65B4B6329771EFF00DABDFB /* ConversationViewController.swift */,
 				D667E5F42135BCD50057A976 /* ConversationTableViewController.swift */,
 				D6C82B5425C5F3F20017F1E6 /* ExpandThreadTableViewCell.swift */,
 				D6C82B5525C5F3F20017F1E6 /* ExpandThreadTableViewCell.xib */,
@@ -1606,6 +1611,7 @@
 				D61F75B0293BD85300C0B37F /* CreateFilterService.swift */,
 				D61F75B2293BD89C00C0B37F /* UpdateFilterService.swift */,
 				D61F75B4293BD97400C0B37F /* DeleteFilterService.swift */,
+				D65B4B6129771A3F00DABDFB /* FetchStatusService.swift */,
 			);
 			path = API;
 			sourceTree = "<group>";
@@ -2008,6 +2014,7 @@
 				D63CC7102911F1E4000E19DE /* UIScrollView+Top.swift in Sources */,
 				D6F6A557291F4F1600F496A8 /* MuteAccountView.swift in Sources */,
 				D6945C3A23AC75E2005C403C /* FindInstanceViewController.swift in Sources */,
+				D65B4B6429771EFF00DABDFB /* ConversationViewController.swift in Sources */,
 				D68E6F59253C9969001A1B4C /* MultiSourceEmojiLabel.swift in Sources */,
 				D63F9C6E241D2D85004C03CF /* CompositionAttachment.swift in Sources */,
 				D6EBF01523C55C0900AE061B /* UIApplication+Scenes.swift in Sources */,
@@ -2027,6 +2034,7 @@
 				D659F36229541065002D944A /* TTTView.swift in Sources */,
 				D6C143DA253510F4007DC240 /* ComposeEmojiTextField.swift in Sources */,
 				D6DD2A3F273C1F4900386A6C /* ComposeAttachmentImage.swift in Sources */,
+				D65B4B6229771A3F00DABDFB /* FetchStatusService.swift in Sources */,
 				D6DD2A45273D6C5700386A6C /* GIFImageView.swift in Sources */,
 				D61F759029353B4300C0B37F /* FileManager+Size.swift in Sources */,
 				0427033822B30F5F000D31B6 /* BehaviorPrefsView.swift in Sources */,

Tusker/API/FetchStatusService.swift

@@ -0,0 +1,47 @@
+//
+//  FetchStatusService.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 1/17/23.
+//  Copyright © 2023 Shadowfacts. All rights reserved.
+//
+
+import Foundation
+import Pachyderm
+
+@MainActor
+class FetchStatusService {
+    let statusID: String
+    let mastodonController: MastodonController
+    
+    init(statusID: String, mastodonController: MastodonController) {
+        self.statusID = statusID
+        self.mastodonController = mastodonController
+    }
+    
+    func run() async -> Result {
+        let response = await mastodonController.runResponse(Client.getStatus(id: statusID))
+        switch response {
+        case .success(let status, _):
+            return .loaded(status)
+        case .failure(let error):
+            switch error.type {
+            case .unexpectedStatus(404), .mastodonError(404, _):
+                self.handleStatusNotFound()
+                return .notFound
+            default:
+                return .error(error)
+            }
+        }
+    }
+    
+    private func handleStatusNotFound() {
+        // todo: remove from persistent store, send notifications
+    }
+    
+    enum Result {
+        case loaded(Status)
+        case notFound
+        case error(Client.Error)
+    }
+}

Tusker/API/MastodonController.swift

@@ -97,19 +97,24 @@ class MastodonController: ObservableObject {
         return client.run(request, completion: completion)
     }
     
-    func run<Result>(_ request: Request<Result>) async throws -> (Result, Pagination?) {
+    func runResponse<Result>(_ request: Request<Result>) async -> Response<Result> {
-        let result: (Result, Pagination?) = try await withCheckedThrowingContinuation({ continuation in
+        let response = await withCheckedContinuation({ continuation in
             client.run(request) { response in
-                switch response {
+                continuation.resume(returning: response)
-                case .failure(let error):
-                    continuation.resume(throwing: error)
-                case .success(let result, let pagination):
-                    continuation.resume(returning: (result, pagination))
-                }
             }
         })
+        return response
+    }
+    
+    func run<Result>(_ request: Request<Result>) async throws -> (Result, Pagination?) {
+        let response = await runResponse(request)
         try Task.checkCancellation()
-        return result
+        switch response {
+        case .failure(let error):
+            throw error
+        case .success(let result, let pagination):
+            return (result, pagination)
+        }
     }
     
     /// - Returns: A tuple of client ID and client secret.

Tusker/Scenes/AuxiliarySceneDelegate.swift

@@ -75,7 +75,7 @@ class AuxiliarySceneDelegate: UIResponder, UIWindowSceneDelegate {
             
         case .showConversation:
             guard let id = UserActivityManager.getConversationStatus(from: activity) else { return nil }
-            return ConversationTableViewController(for: id, mastodonController: mastodonController)
+            return ConversationViewController(for: id, state: .unknown, mastodonController: mastodonController)
             
         case .checkNotifications:
             guard let mode = UserActivityManager.getNotificationsMode(from: activity) else { return nil }

Tusker/Screens/Conversation/ConversationTableViewController.swift

@@ -22,11 +22,6 @@ class ConversationNode {
 
 class ConversationTableViewController: EnhancedTableViewController {
     
-    static let showPostsImage = UIImage(systemName: "eye.fill")!
-    static let hidePostsImage = UIImage(systemName: "eye.slash.fill")!
-    
-    static let bottomSeparatorTag = 101
-    
     weak var mastodonController: MastodonController!
     
     let mainStatusID: String
@@ -35,11 +30,8 @@ class ConversationTableViewController: EnhancedTableViewController {
     private(set) var dataSource: UITableViewDiffableDataSource<Section, Item>!
     
     var showStatusesAutomatically = false
-    var visibilityBarButtonItem: UIBarButtonItem!
     
-    private var loadingState = LoadingState.unloaded
+    init(for mainStatusID: String, state: CollapseState, mastodonController: MastodonController) {
-    
-    init(for mainStatusID: String, state: CollapseState = .unknown, mastodonController: MastodonController) {
         self.mainStatusID = mainStatusID
         self.mainStatusState = state
         self.statusIDToScrollToOnLoad = mainStatusID
@@ -57,8 +49,6 @@ class ConversationTableViewController: EnhancedTableViewController {
     override func viewDidLoad() {
         super.viewDidLoad()
         
-        title = NSLocalizedString("Conversation", comment: "conversation screen title")
-
         tableView.delegate = self
         tableView.dataSource = self
         tableView.prefetchDataSource = self
@@ -99,9 +89,9 @@ class ConversationTableViewController: EnhancedTableViewController {
                 
                 cell.setShowThreadLinks(prev: !firstInSection, next: !lastInSection)
                 if lastInSection {
-                    if cell.viewWithTag(ConversationTableViewController.bottomSeparatorTag) == nil {
+                    if cell.viewWithTag(ViewTags.conversationBottomSeparator) == nil {
                         let separator = UIView()
-                        separator.tag = ConversationTableViewController.bottomSeparatorTag
+                        separator.tag = ViewTags.conversationBottomSeparator
                         separator.translatesAutoresizingMaskIntoConstraints = false
                         separator.backgroundColor = tableView.separatorColor
                         cell.addSubview(separator)
@@ -113,7 +103,7 @@ class ConversationTableViewController: EnhancedTableViewController {
                         ])
                     }
                 } else {
-                    cell.viewWithTag(ConversationTableViewController.bottomSeparatorTag)?.removeFromSuperview()
+                    cell.viewWithTag(ViewTags.conversationBottomSeparator)?.removeFromSuperview()
                 }
                 
                 return cell
@@ -124,97 +114,24 @@ class ConversationTableViewController: EnhancedTableViewController {
                 return cell
             }
         })
-        
-        visibilityBarButtonItem = UIBarButtonItem(image: ConversationTableViewController.showPostsImage, style: .plain, target: self, action: #selector(toggleVisibilityButtonPressed))
-        updateVisibilityBarButtonItem()
-        navigationItem.rightBarButtonItem = visibilityBarButtonItem
-        // disable transparent background when scroll to top because it looks weird when items earlier in the thread load in
-        // (it remains transparent slightly too long, resulting in a flash of the content under the transparent bar)
-        let appearance = UINavigationBarAppearance()
-        appearance.configureWithDefaultBackground()
-        navigationItem.scrollEdgeAppearance = appearance
-        
-        Task {
-            await loadMainStatus()
-        }
     }
     
-    private func updateVisibilityBarButtonItem() {
+    func addMainStatus(_ status: StatusMO) {
-        visibilityBarButtonItem.isSelected = showStatusesAutomatically
+        loadViewIfNeeded()
-        visibilityBarButtonItem.accessibilityLabel = showStatusesAutomatically ? "Collapse All" : "Expand All"
-    }
         
-    @MainActor
-    private func loadMainStatus() async {
-        guard loadingState == .unloaded else { return }
-        
-        if let mainStatus = mastodonController.persistentContainer.status(for: mainStatusID) {
-            await mainStatusLoaded(mainStatus)
-        } else {
-            loadingState = .loadingMain
-            let req = Client.getStatus(id: mainStatusID)
-            do {
-                let (status, _) = try await mastodonController.run(req)
-                let statusMO = mastodonController.persistentContainer.addOrUpdateOnViewContext(status: status)
-                await mainStatusLoaded(statusMO)
-            } catch {
-                let error = error as! Client.Error
-                loadingState = .unloaded
-                let config = ToastConfiguration(from: error, with: "Error Loading Status", in: self) { [weak self] toast in
-                    toast.dismissToast(animated: true)
-                    await self?.loadMainStatus()
-                }
-                showToast(configuration: config, animated: true)
-                return
-            }
-        }
-    }
-    
-    private func mainStatusLoaded(_ mainStatus: StatusMO) async {
         let mainStatusItem = Item.status(id: mainStatusID, state: mainStatusState)
-        
         var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
         snapshot.appendSections([.statuses])
         snapshot.appendItems([mainStatusItem], toSection: .statuses)
-        await dataSource.apply(snapshot, animatingDifferences: false)
+        dataSource.apply(snapshot, animatingDifferences: false)
-
-        loadingState = .loadedMain
-
-        await loadContext(for: mainStatus)
     }
     
-    @MainActor
+    func addContext(_ context: ConversationContext, for mainStatus: StatusMO) async {
-    private func loadContext(for mainStatus: StatusMO) async {
+        let parentIDs = self.getDirectParents(inReplyTo: mainStatus.inReplyToID, from: context.ancestors)
-        guard loadingState == .loadedMain else { return }
+        let parentStatuses = context.ancestors.filter { parentIDs.contains($0.id) }
         
-        loadingState = .loadingContext
+        await mastodonController.persistentContainer.addAll(statuses: parentStatuses + context.descendants)
         
-        // save the id here because we can't access the MO from the whatever thread the network callback happens on
-        let mainStatusInReplyToID = mainStatus.inReplyToID
-        
-        // todo: it would be nice to cache these contexts
-        let request = Status.getContext(mainStatusID)
-        do {
-            let (context, _) = try await mastodonController.run(request)
-            let parentIDs = self.getDirectParents(inReplyTo: mainStatusInReplyToID, from: context.ancestors)
-            let parentStatuses = context.ancestors.filter { parentIDs.contains($0.id) }
-            
-            await mastodonController.persistentContainer.addAll(statuses: parentStatuses + context.descendants)
-            self.contextLoaded(mainStatus: mainStatus, context: context, parentIDs: parentIDs)
-            
-        } catch {
-            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)
-                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)
         
         var snapshot = self.dataSource.snapshot()
@@ -249,8 +166,6 @@ class ConversationTableViewController: EnhancedTableViewController {
                 self.tableView.scrollToRow(at: indexPath, at: position, animated: false)
             }
         }
-        
-        self.loadingState = .loadedAll
     }
 
     private func getDirectParents(inReplyTo inReplyToID: String?, from statuses: [Status]) -> [String] {
@@ -378,9 +293,7 @@ class ConversationTableViewController: EnhancedTableViewController {
         return (tableView.cellForRow(at: indexPath) as? TableViewSwipeActionProvider)?.trailingSwipeActionsConfiguration()
     }
 
-    @objc func toggleVisibilityButtonPressed() {
+    func updateVisibleCellCollapseState() {
-        showStatusesAutomatically = !showStatusesAutomatically
-        
         let snapshot = dataSource.snapshot()
         for case let .status(id: _, state: state) in snapshot.itemIdentifiers where state.collapsible == true {
             state.collapsed = !showStatusesAutomatically
@@ -396,10 +309,7 @@ class ConversationTableViewController: EnhancedTableViewController {
         // recalculate cell heights
         tableView.beginUpdates()
         tableView.endUpdates()
-
-        updateVisibilityBarButtonItem()
     }
-
 }
 
 extension ConversationTableViewController {
@@ -436,21 +346,11 @@ extension ConversationTableViewController {
     }
 }
 
-extension ConversationTableViewController {
-    private enum LoadingState: Equatable {
-        case unloaded
-        case loadingMain
-        case loadedMain
-        case loadingContext
-        case loadedAll
-    }
-}
-
 extension ConversationTableViewController: TuskerNavigationDelegate {
     var apiController: MastodonController! { mastodonController }
     
-    func conversation(mainStatusID: String, state: CollapseState) -> ConversationTableViewController {
+    func conversation(mainStatusID: String, state: CollapseState) -> ConversationViewController {
-        let vc = ConversationTableViewController(for: mainStatusID, state: state, mastodonController: mastodonController)
+        let vc = ConversationViewController(for: mainStatusID, state: state, mastodonController: mastodonController)
         // transfer show statuses automatically state when showing new conversation
         vc.showStatusesAutomatically = self.showStatusesAutomatically
         return vc

Tusker/Screens/Conversation/ConversationViewController.swift

@@ -0,0 +1,262 @@
+//
+//  ConversationViewController.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 1/17/23.
+//  Copyright © 2023 Shadowfacts. All rights reserved.
+//
+
+import UIKit
+import Pachyderm
+
+class ConversationViewController: UIViewController {
+    
+    weak var mastodonController: MastodonController!
+    
+    let mainStatusID: String
+    let mainStatusState: CollapseState
+    var statusIDToScrollToOnLoad: String {
+        didSet {
+            if case .displaying(let vc) = state {
+                vc.statusIDToScrollToOnLoad = statusIDToScrollToOnLoad
+            }
+        }
+    }
+    var showStatusesAutomatically = false {
+        didSet {
+            if case .displaying(let vc) = state {
+                vc.showStatusesAutomatically = showStatusesAutomatically
+            }
+        }
+    }
+    
+    private var collapseBarButtonItem: UIBarButtonItem!
+    
+    private var state: State = .unloaded {
+        didSet {
+            switch oldValue {
+            case .loading(let indicator):
+                indicator.removeFromSuperview()
+            case .displaying(let vc):
+                vc.removeViewAndController()
+            default:
+                break
+            }
+            
+            switch state {
+            case .unloaded:
+                break
+            case .loading(let indicator):
+                indicator.translatesAutoresizingMaskIntoConstraints = false
+                view.addSubview(indicator)
+                NSLayoutConstraint.activate([
+                    indicator.centerXAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerXAnchor),
+                    indicator.centerYAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerYAnchor),
+                ])
+            case .displaying(let vc):
+                embedChild(vc)
+            case .notFound:
+                showMainStatusNotFound()
+            }
+            
+            updateVisibilityBarButtonItem()
+        }
+    }
+    
+    init(for mainStatusID: String, state mainStatusState: CollapseState, mastodonController: MastodonController) {
+        self.mainStatusID = mainStatusID
+        self.mainStatusState = mainStatusState
+        self.statusIDToScrollToOnLoad = mainStatusID
+        self.mastodonController = mastodonController
+        
+        super.init(nibName: nil, bundle: nil)
+    }
+    
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+    
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        
+        title = NSLocalizedString("Conversation", comment: "conversation screen title")
+
+        view.backgroundColor = .secondarySystemBackground
+        
+        collapseBarButtonItem = UIBarButtonItem(image: UIImage(systemName: "eye.fill")!, style: .plain, target: self, action: #selector(toggleCollapseButtonPressed))
+        updateVisibilityBarButtonItem()
+        navigationItem.rightBarButtonItem = collapseBarButtonItem
+        // disable transparent background when scroll to top because it looks weird when items earlier in the thread load in
+        // (it remains transparent slightly too long, resulting in a flash of the content under the transparent bar)
+        let appearance = UINavigationBarAppearance()
+        appearance.configureWithDefaultBackground()
+        navigationItem.scrollEdgeAppearance = appearance
+    }
+    
+    private func updateVisibilityBarButtonItem() {
+        switch state {
+        case .loading(_), .displaying(_):
+            collapseBarButtonItem.isEnabled = true
+        default:
+            collapseBarButtonItem.isEnabled = false
+        }
+        
+        collapseBarButtonItem.isSelected = showStatusesAutomatically
+        collapseBarButtonItem.accessibilityLabel = showStatusesAutomatically ? "Collapse All" : "Expand All"
+    }
+    
+    override func viewWillAppear(_ animated: Bool) {
+        super.viewWillAppear(animated)
+        
+        Task {
+            await loadMainStatus()
+        }
+    }
+    
+    // MARK: Loading
+    
+    private func loadMainStatus() async {
+        @MainActor
+        func doLoadMainStatus() async -> StatusMO? {
+            switch await FetchStatusService(statusID: mainStatusID, mastodonController: mastodonController).run() {
+            case .loaded(let status):
+                return mastodonController.persistentContainer.addOrUpdateOnViewContext(status: status)
+            case .notFound:
+                state = .notFound
+                showMainStatusNotFound()
+                return nil
+            case .error(let error):
+                self.showMainStatusError(error)
+                return nil
+            }
+        }
+        
+        
+        if let cached = mastodonController.persistentContainer.status(for: mainStatusID) {
+            // if we have a cached copy, display it immediately but still try to refresh it
+            Task {
+                await doLoadMainStatus()
+            }
+            await mainStatusLoaded(cached)
+        } else {
+            // otherwise, show a loading indicator while loading the main status
+            let indicator = UIActivityIndicatorView(style: .medium)
+            indicator.startAnimating()
+            state = .loading(indicator)
+            
+            if let status = await doLoadMainStatus() {
+                await mainStatusLoaded(status)
+            }
+        }
+    }
+    
+    @MainActor
+    private func mainStatusLoaded(_ mainStatus: StatusMO) async {
+        let vc = ConversationTableViewController(for: mainStatusID, state: mainStatusState, mastodonController: mastodonController)
+        vc.statusIDToScrollToOnLoad = statusIDToScrollToOnLoad
+        vc.showStatusesAutomatically = showStatusesAutomatically
+        vc.addMainStatus(mainStatus)
+        state = .displaying(vc)
+        
+        await loadContext(for: mainStatus)
+    }
+    
+    @MainActor
+    private func loadContext(for mainStatus: StatusMO) async {
+        guard case .displaying(_) = state else {
+            return
+        }
+        
+        let request = Status.getContext(mainStatus.id)
+        do {
+            let (context, _) = try await mastodonController.run(request)
+            guard case .displaying(let vc) = state else {
+                return
+            }
+            
+            await vc.addContext(context, for: mainStatus)
+        } catch {
+            guard case .displaying(_) = state else {
+                return
+            }
+            let error = error as! Client.Error
+            
+            let config = ToastConfiguration(from: error, with: "Error Loading Context", in: self) { [weak self] toast in
+                toast.dismissToast(animated: true)
+                await self?.loadContext(for: mainStatus)
+            }
+            self.showToast(configuration: config, animated: true)
+        }
+    }
+    
+    private func showMainStatusNotFound() {
+        let emoji = UILabel()
+        emoji.font = .systemFont(ofSize: 64)
+        emoji.text = "🤷"
+        
+        let title = UILabel()
+        title.textColor = .secondaryLabel
+        title.font = .preferredFont(forTextStyle: .title1).withTraits(.traitBold)!
+        title.adjustsFontForContentSizeCategory = true
+        title.text = "Not Found"
+        
+        let subtitle = UILabel()
+        subtitle.textColor = .secondaryLabel
+        subtitle.font = .preferredFont(forTextStyle: .body)
+        subtitle.adjustsFontForContentSizeCategory = true
+        subtitle.text = "The post you are looking for may have been deleted, or may not be visible to you."
+        subtitle.numberOfLines = 0
+        subtitle.textAlignment = .center
+        
+        let stack = UIStackView(arrangedSubviews: [
+            emoji,
+            title,
+            subtitle,
+        ])
+        stack.axis = .vertical
+        stack.alignment = .center
+        stack.spacing = 8
+        stack.isAccessibilityElement = true
+        stack.accessibilityLabel = "\(title.text!). \(subtitle.text!)"
+        
+        stack.translatesAutoresizingMaskIntoConstraints = false
+        view.addSubview(stack)
+        NSLayoutConstraint.activate([
+            stack.leadingAnchor.constraint(equalToSystemSpacingAfter: view.safeAreaLayoutGuide.leadingAnchor, multiplier: 1),
+            view.safeAreaLayoutGuide.trailingAnchor.constraint(equalToSystemSpacingAfter: stack.trailingAnchor, multiplier: 1),
+            stack.centerYAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerYAnchor),
+        ])
+    }
+    
+    private func showMainStatusError(_ error: Client.Error) {
+        let config = ToastConfiguration(from: error, with: "Error Loading Status", in: self) { [weak self] toast in
+            toast.dismissToast(animated: true)
+            await self?.loadMainStatus()
+        }
+        self.showToast(configuration: config, animated: true)
+    }
+    
+    // MARK: Interaction
+    
+    @objc func toggleCollapseButtonPressed() {
+        guard case .displaying(let vc) = state else {
+            return
+        }
+        showStatusesAutomatically = !showStatusesAutomatically
+        vc.updateVisibleCellCollapseState()
+        updateVisibilityBarButtonItem()
+    }
+
+}
+
+extension ConversationViewController {
+    enum State {
+        case unloaded
+        case loading(UIActivityIndicatorView)
+        case displaying(ConversationTableViewController)
+        case notFound
+    }
+}
+
+extension ConversationViewController: ToastableViewController {
+}

Tusker/TuskerNavigationDelegate.swift

@@ -13,7 +13,7 @@ import Pachyderm
 protocol TuskerNavigationDelegate: UIViewController, ToastableViewController {
     var apiController: MastodonController! { get }
     
-    func conversation(mainStatusID: String, state: CollapseState) -> ConversationTableViewController
+    func conversation(mainStatusID: String, state: CollapseState) -> ConversationViewController
 }
 
 extension TuskerNavigationDelegate {
@@ -78,8 +78,8 @@ extension TuskerNavigationDelegate {
         }
     }
     
-    func conversation(mainStatusID: String, state: CollapseState) -> ConversationTableViewController {
+    func conversation(mainStatusID: String, state: CollapseState) -> ConversationViewController {
-        return ConversationTableViewController(for: mainStatusID, state: state, mastodonController: apiController)
+        return ConversationViewController(for: mainStatusID, state: state, mastodonController: apiController)
     }
     
     func selected(status statusID: String) {

Tusker/ViewTags.swift

@@ -16,4 +16,5 @@ struct ViewTags {
     static let navEmptyTitleView = 42003
     static let splitNavCloseSecondaryButton = 42004
     static let customAlertSeparator = 42005
+    static let conversationBottomSeparator = 42006
 }

Tusker/Views/Status/TimelineStatusCollectionViewCell.swift

@@ -759,7 +759,7 @@ class TimelineStatusCollectionViewCell: UICollectionViewListCell, StatusCollecti
             return nil
         }
         return UIContextMenuConfiguration {
-            ConversationTableViewController(for: self.statusID, state: self.statusState.copy(), mastodonController: self.mastodonController)
+            ConversationViewController(for: self.statusID, state: self.statusState.copy(), mastodonController: self.mastodonController)
         } actionProvider: { _ in
             UIMenu(children: self.delegate!.actionsForStatus(status, source: .view(self)))
         }

Tusker/Views/Status/TimelineStatusTableViewCell.swift

@@ -433,7 +433,7 @@ extension TimelineStatusTableViewCell: MenuPreviewProvider {
             return nil
         }
         return (
-            content: { ConversationTableViewController(for: self.statusID, state: self.statusState.copy(), mastodonController: mastodonController) },
+            content: { ConversationViewController(for: self.statusID, state: self.statusState.copy(), mastodonController: mastodonController) },
             actions: { self.delegate?.actionsForStatus(status, source: .view(self)) ?? [] }
         )
     }