From 727615a8181d825a013feb526e83ebba3c71e3b7 Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Tue, 29 Mar 2022 12:52:14 -0400
Subject: [PATCH] Fix crash when providing account actions before own account
 is loaded

---
 Tusker/Controllers/MastodonController.swift | 13 ++++
 Tusker/Screens/Utilities/Previewing.swift   | 71 ++++++++++-----------
 2 files changed, 46 insertions(+), 38 deletions(-)

diff --git a/Tusker/Controllers/MastodonController.swift b/Tusker/Controllers/MastodonController.swift
index d6a02862ad..a9263e9062 100644
--- a/Tusker/Controllers/MastodonController.swift
+++ b/Tusker/Controllers/MastodonController.swift
@@ -67,6 +67,19 @@ class MastodonController: ObservableObject {
         return client.run(request, completion: completion)
     }
     
+    func run<Result>(_ request: Request<Result>) async throws -> (Result, Pagination?) {
+        return try await withCheckedThrowingContinuation({ continuation in
+            client.run(request) { response in
+                switch response {
+                case .failure(let error):
+                    continuation.resume(throwing: error)
+                case .success(let result, let pagination):
+                    continuation.resume(returning: (result, pagination))
+                }
+            }
+        })
+    }
+    
     /// - Returns: A tuple of client ID and client secret.
     func registerApp() async throws -> (String, String) {
         if let clientID = client.clientID,
diff --git a/Tusker/Screens/Utilities/Previewing.swift b/Tusker/Screens/Utilities/Previewing.swift
index d7e180bca5..2483746c33 100644
--- a/Tusker/Screens/Utilities/Previewing.swift
+++ b/Tusker/Screens/Utilities/Previewing.swift
@@ -48,50 +48,21 @@ extension MenuPreviewProvider {
             ]
         }
         
-        var actionsSection: [UIMenuElement] = [
+        let actionsSection: [UIMenuElement] = [
             createAction(identifier: "sendmessage", title: "Send Message", systemImageName: "envelope", handler: { [weak self] (_) in
                 guard let self = self else { return }
                 self.navigationDelegate?.compose(mentioningAcct: account.acct)
             }),
-        ]
-        
-        if accountID != mastodonController.account.id {
-            actionsSection.append(UIDeferredMenuElement({ (elementHandler) in
-                guard let mastodonController = self.mastodonController else {
-                    elementHandler([])
-                    return
-                }
-                let request = Client.getRelationships(accounts: [account.id])
-                // talk about callback hell :/
-                mastodonController.run(request) { [weak self] (response) in
-                    guard let self = self,
-                          case let .success(results, _) = response,
-                          let relationship = results.first else {
-                              DispatchQueue.main.async {
-                                  elementHandler([])
-                              }
-                              return
-                          }
-                    let following = relationship.following
-                    DispatchQueue.main.async {
-                        let action = self.createAction(identifier: "follow", title: following ? "Unfollow" : "Follow", systemImageName: following ? "person.badge.minus" : "person.badge.plus", handler: { (_) in
-                            let request = (following ? Account.unfollow : Account.follow)(accountID)
-                            mastodonController.run(request) { (response) in
-                                switch response {
-                                case .failure(_):
-                                    fatalError()
-                                case let .success(relationship, _):
-                                    mastodonController.persistentContainer.addOrUpdate(relationship: relationship)
-                                }
-                            }
-                        })
-                        elementHandler([
-                            action
-                        ])
+            UIDeferredMenuElement({ (elementHandler) in
+                Task { @MainActor in
+                    if let action = await self.followAction(for: accountID, mastodonController: mastodonController) {
+                        elementHandler([action])
+                    } else {
+                        elementHandler([])
                     }
                 }
-            }))
-        }
+            })
+        ]
         
         var shareSection = [
             openInSafariAction(url: account.url),
@@ -267,6 +238,30 @@ extension MenuPreviewProvider {
         }
     }
     
+    private func followAction(for accountID: String, mastodonController: MastodonController) async -> UIMenuElement? {
+        guard let ownAccount = try? await mastodonController.getOwnAccount(),
+              accountID != ownAccount.id else {
+            return nil
+        }
+        let request = Client.getRelationships(accounts: [accountID])
+        guard let (relationships, _) = try? await mastodonController.run(request),
+              let relationship = relationships.first else {
+            return nil
+        }
+        let following = relationship.following
+        return createAction(identifier: "follow", title: following ? "Unfollow" : "Follow", systemImageName: following ? "person.badge.minus" : "person.badge.plus") { _ in
+            let request = (following ? Account.unfollow : Account.follow)(accountID)
+            mastodonController.run(request) { response in
+                switch response {
+                case .failure(_):
+                    fatalError()
+                case .success(let relationship, _):
+                    mastodonController.persistentContainer.addOrUpdate(relationship: relationship)
+                }
+            }
+        }
+    }
+    
 }
 
 extension LargeImageViewController: CustomPreviewPresenting {