Fix crash when creating list fails

Closes #212

Tusker.xcodeproj/project.pbxproj

@@ -312,6 +312,7 @@
 		D6F2E966249E8BFD005846BB /* IssueReporterViewController.xib in Resources */ = {isa = PBXBuildFile; fileRef = D6F2E964249E8BFD005846BB /* IssueReporterViewController.xib */; };
 		D6F6A54C291EF6FE00F496A8 /* EditListSearchResultsContainerViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6F6A54B291EF6FE00F496A8 /* EditListSearchResultsContainerViewController.swift */; };
 		D6F6A54E291EF7E100F496A8 /* EditListSearchFollowingViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6F6A54D291EF7E100F496A8 /* EditListSearchFollowingViewController.swift */; };
+		D6F6A550291F058600F496A8 /* CreateListService.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6F6A54F291F058600F496A8 /* CreateListService.swift */; };
 		D6F953F021251A2900CF0F2B /* MastodonController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6F953EF21251A2900CF0F2B /* MastodonController.swift */; };
 		D6FF9860255C717400845181 /* AccountSwitchingContainerViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6FF985F255C717400845181 /* AccountSwitchingContainerViewController.swift */; };
 /* End PBXBuildFile section */
@@ -679,6 +680,7 @@
 		D6F2E964249E8BFD005846BB /* IssueReporterViewController.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = IssueReporterViewController.xib; sourceTree = "<group>"; };
 		D6F6A54B291EF6FE00F496A8 /* EditListSearchResultsContainerViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EditListSearchResultsContainerViewController.swift; sourceTree = "<group>"; };
 		D6F6A54D291EF7E100F496A8 /* EditListSearchFollowingViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EditListSearchFollowingViewController.swift; sourceTree = "<group>"; };
+		D6F6A54F291F058600F496A8 /* CreateListService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CreateListService.swift; sourceTree = "<group>"; };
 		D6F953EF21251A2900CF0F2B /* MastodonController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MastodonController.swift; sourceTree = "<group>"; };
 		D6FF985F255C717400845181 /* AccountSwitchingContainerViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AccountSwitchingContainerViewController.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
@@ -1488,6 +1490,7 @@
 				D6E9CDA7281A427800BBC98E /* PostService.swift */,
 				D61ABEFD28F1C92600B29151 /* FavoriteService.swift */,
 				D621733228F1D5ED004C7DB1 /* ReblogService.swift */,
+				D6F6A54F291F058600F496A8 /* CreateListService.swift */,
 			);
 			path = API;
 			sourceTree = "<group>";
@@ -1915,6 +1918,7 @@
 				D681E4D3246E2AFF0053414F /* MuteConversationActivity.swift in Sources */,
 				D6969EA0240C8384002843CE /* EmojiLabel.swift in Sources */,
 				D64BC18623C1253A000D0238 /* AssetPreviewViewController.swift in Sources */,
+				D6F6A550291F058600F496A8 /* CreateListService.swift in Sources */,
 				D6BEA24B291C6A2B002F4D01 /* AlertWithData.swift in Sources */,
 				D61ABEFE28F1C92600B29151 /* FavoriteService.swift in Sources */,
 				D663626221360B1900C9CBA2 /* Preferences.swift in Sources */,

Tusker/API/CreateListService.swift

@@ -0,0 +1,70 @@
+//
+//  CreateListService.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 11/11/22.
+//  Copyright © 2022 Shadowfacts. All rights reserved.
+//
+
+import UIKit
+import Pachyderm
+
+@MainActor
+class CreateListService {
+    private let mastodonController: MastodonController
+    private let present: (UIViewController) -> Void
+    private let didCreateList: (@MainActor (List) -> Void)?
+    
+    private var createAction: UIAlertAction?
+    
+    init(mastodonController: MastodonController, present: @escaping (UIViewController) -> Void, didCreateList: (@MainActor (List) -> Void)?) {
+        self.mastodonController = mastodonController
+        self.present = present
+        self.didCreateList = didCreateList
+    }
+    
+    func run() {
+        let alert = UIAlertController(title: NSLocalizedString("New List", comment: "new list alert title"), message: NSLocalizedString("Choose a title for your new list", comment: "new list alert message"), preferredStyle: .alert)
+        alert.addTextField { textField in
+            textField.addTarget(self, action: #selector(self.alertTextFieldValueChanged), for: .editingChanged)
+        }
+        alert.addAction(UIAlertAction(title: NSLocalizedString("Cancel", comment: "new list alert cancel button"), style: .cancel, handler: nil))
+        createAction = UIAlertAction(title: NSLocalizedString("Create List", comment: "new list create button"), style: .default, handler: { (_) in
+            let textField = alert.textFields!.first!
+            let title = textField.text ?? ""
+            Task {
+                await self.createList(with: title)
+            }
+        })
+        createAction!.isEnabled = false
+        alert.addAction(createAction!)
+        present(alert)
+    }
+    
+    @objc private func alertTextFieldValueChanged(_ textField: UITextField) {
+        createAction?.isEnabled = textField.text?.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty == false
+    }
+    
+    private func createList(with title: String) async {
+        do {
+            let request = Client.createList(title: title)
+            let (list, _) = try await mastodonController.run(request)
+            NotificationCenter.default.post(name: .listsChanged, object: nil)
+            self.didCreateList?(list)
+        } catch {
+            let alert = UIAlertController(title: "Error Creating List", message: error.localizedDescription, preferredStyle: .alert)
+            alert.addAction(UIAlertAction(title: "Cancel", style: .cancel))
+            alert.addAction(UIAlertAction(title: "Retry", style: .default, handler: { _ in
+                Task {
+                    await self.createList(with: title)
+                }
+            }))
+            present(alert)
+        }
+    }
+    
+}
+
+extension Foundation.Notification.Name {
+    static let listsChanged = Notification.Name("listsChanged")
+}

Tusker/Screens/Explore/ExploreViewController.swift

@@ -70,6 +70,7 @@ class ExploreViewController: UIViewController, UICollectionViewDelegate {
         
         NotificationCenter.default.addObserver(self, selector: #selector(savedHashtagsChanged), name: .savedHashtagsChanged, object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(savedInstancesChanged), name: .savedInstancesChanged, object: nil)
+        NotificationCenter.default.addObserver(self, selector: #selector(reloadLists), name: .listsChanged, object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(preferencesChanged), name: .preferencesChanged, object: nil)
     }
     
@@ -178,7 +179,7 @@ class ExploreViewController: UIViewController, UICollectionViewDelegate {
         self.dataSource.apply(snapshot)
     }
     
-    private func reloadLists() {
+    @objc private func reloadLists() {
         let request = Client.getLists()
         mastodonController.run(request) { (response) in
             guard case let .success(lists, _) = response else {
@@ -356,28 +357,12 @@ class ExploreViewController: UIViewController, UICollectionViewDelegate {
             
         case .addList:
             collectionView.deselectItem(at: indexPath, animated: true)
-            let alert = UIAlertController(title: NSLocalizedString("New List", comment: "new list alert title"), message: NSLocalizedString("Choose a title for your new list", comment: "new list alert message"), preferredStyle: .alert)
+            let service = CreateListService(mastodonController: mastodonController, present: { self.present($0, animated: true) }) { list in
-            alert.addTextField(configurationHandler: nil)
-            alert.addAction(UIAlertAction(title: NSLocalizedString("Cancel", comment: "new list alert cancel button"), style: .cancel, handler: nil))
-            alert.addAction(UIAlertAction(title: NSLocalizedString("Create List", comment: "new list create button"), style: .default, handler: { (_) in
-                guard let title = alert.textFields?.first?.text else {
-                    fatalError()
-                }
-                
-                let request = Client.createList(title: title)
-                self.mastodonController.run(request) { (response) in
-                    guard case let .success(list, _) = response else { fatalError() }
-                    
-                    self.reloadLists()
-                    
-                    DispatchQueue.main.async {
                 let listTimelineController = ListTimelineViewController(for: list, mastodonController: self.mastodonController)
                 listTimelineController.presentEditOnAppear = true
                 self.show(listTimelineController, sender: nil)
             }
-                }
+            service.run()
-            }))
-            present(alert, animated: true)
             
         case let .savedHashtag(hashtag):
             show(HashtagTimelineViewController(for: hashtag, mastodonController: mastodonController), sender: nil)

Tusker/Screens/Main/MainSidebarViewController.swift

@@ -99,6 +99,7 @@ class MainSidebarViewController: UIViewController {
         
         NotificationCenter.default.addObserver(self, selector: #selector(reloadSavedHashtags), name: .savedHashtagsChanged, object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(reloadSavedInstances), name: .savedInstancesChanged, object: nil)
+        NotificationCenter.default.addObserver(self, selector: #selector(reloadLists), name: .listsChanged, object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(preferencesChanged), name: .preferencesChanged, object: nil)
         
         onViewDidLoad?()
@@ -201,7 +202,7 @@ class MainSidebarViewController: UIViewController {
         }
     }
     
-    private func reloadLists() {
+    @objc private func reloadLists() {
         let request = Client.getLists()
         mastodonController.run(request) { [weak self] (response) in
             guard let self = self, case let .success(lists, _) = response else { return }
@@ -297,28 +298,12 @@ class MainSidebarViewController: UIViewController {
         }
     }
 
-    // todo: deduplicate with ExploreViewController
     private func showAddList() {
-        let alert = UIAlertController(title: "New List", message: "Choose a title for your new list", preferredStyle: .alert)
+        let service = CreateListService(mastodonController: mastodonController, present: { self.present($0, animated: true
-        alert.addTextField(configurationHandler: nil)
+        ) }) { list in
-        alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
-        alert.addAction(UIAlertAction(title: "Create List", style: .default, handler: { (_) in
-            guard let title = alert.textFields?.first?.text else {
-                fatalError()
-            }
-            
-            let request = Client.createList(title: title)
-            self.mastodonController.run(request) { (response) in
-                guard case let .success(list, _) = response else { fatalError() }
-                
-                self.reloadLists()
-                
-                DispatchQueue.main.async {
             self.sidebarDelegate?.sidebar(self, didSelectItem: .list(list))
         }
-            }
+        service.run()
-        }))
-        present(alert, animated: true)
     }
     
     // todo: deduplicate with ExploreViewController