IOS-271: Fix translate functionality leads to empty status content (#…

…1320)

This PR solves the following things:

1. Fixes the post body being set to an empty string in case translation
fails
2. Fetches `/api/v1/instance/translation_languages` (only if the
`/api/v2/instance` is available) and checks if the transaction between
the desired languages is possible
3. Refactors `Instance` usage to now use
`MastodonAuthentication.InstanceConfiguration` if feasible with low
effort
4. On the home timeline, the reblog status (the wrapper) is taken into
account for translation which leads to the translation failing

Mastodon/Protocol/Provider/DataSourceFacade+Status.swift

@@ -317,13 +317,14 @@ extension DataSourceFacade {
                 performDeletion(of: status, with: dependency)
             }
         case .translateStatus:
-            guard let status = menuContext.statusViewModel?.originalStatus else { return }
+            guard let status = menuContext.statusViewModel?.originalStatus?.reblog ?? menuContext.statusViewModel?.originalStatus else { return }
 
             do {
                 let translation = try await DataSourceFacade.translateStatus(provider: dependency,status: status)
 
                 menuContext.statusViewModel?.translation = translation
             } catch TranslationFailure.emptyOrInvalidResponse {
+                menuContext.statusViewModel?.isCurrentlyTranslating = false
                 let alertController = UIAlertController(title: L10n.Common.Alerts.TranslationFailed.title, message: L10n.Common.Alerts.TranslationFailed.message, preferredStyle: .alert)
                 alertController.addAction(UIAlertAction(title: L10n.Common.Alerts.TranslationFailed.button, style: .default))
                 dependency.present(alertController, animated: true)

Mastodon/Protocol/Provider/DataSourceFacade+Translate.swift

@@ -21,7 +21,7 @@ extension DataSourceFacade {
     public static func translateStatus(
         provider: Provider,
         status: MastodonStatus
-    ) async throws -> Mastodon.Entity.Translation? {
+    ) async throws -> Mastodon.Entity.Translation {
         FeedbackGenerator.shared.generate(.selectionChanged)
 
         do {
@@ -32,10 +32,10 @@ extension DataSourceFacade {
                     authenticationBox: provider.authContext.mastodonAuthenticationBox
                 ).value
 
-            if value.content != nil {
+            if let content = value.content, content.isNotEmpty {
                 return value
             } else {
-                return nil
+                throw TranslationFailure.emptyOrInvalidResponse
             }
 
         } catch {

Mastodon/Scene/Profile/ProfileViewController.swift

@@ -995,8 +995,8 @@ extension ProfileViewController: PagerTabStripNavigateable {
 }
 
 private extension ProfileViewController {
-    var currentInstance: Instance? {
-        authContext.mastodonAuthenticationBox.authentication.instance(in: context.managedObjectContext)
+    var currentInstance: MastodonAuthentication.InstanceConfiguration? {
+        authContext.mastodonAuthenticationBox.authentication.instanceConfiguration
     }
 }
 

MastodonSDK/Sources/CoreDataStack/Entity/Mastodon/MastodonAuthentication.swift

@@ -29,11 +29,7 @@ final public class MastodonAuthenticationLegacy: NSManagedObject {
     @NSManaged public private(set) var activedAt: Date
 
     // one-to-one relationship
-    @NSManaged public private(set) var user: MastodonUser
-
-    // many-to-one relationship
-    @NSManaged public private(set) var instance: Instance?
-
+    @NSManaged public private(set) var user: MastodonUser    
 }
 
 extension MastodonAuthenticationLegacy {
@@ -101,12 +97,6 @@ extension MastodonAuthenticationLegacy {
         }
     }
 
-    public func update(instance: Instance) {
-        if self.instance != instance {
-            self.instance = instance
-        }
-    }
-
     public func didUpdate(at networkDate: Date) {
         self.updatedAt = networkDate
     }

MastodonSDK/Sources/MastodonCore/AuthenticationServiceProvider.swift

@@ -22,12 +22,35 @@ public class AuthenticationServiceProvider: ObservableObject {
             persist() // todo: Is this too heavy and too often here???
         }
     }
-
-    func update(instance: Instance, where domain: String) {
+
+    @MainActor
+    @discardableResult
+    func updating(instanceV1 instance: Mastodon.Entity.Instance, for domain: String) -> Self {
+        authentications = authentications.map { authentication in
+            guard authentication.domain == domain else { return authentication }
+            return authentication.updating(instanceV1: instance)
+        }
+        return self
+    }
+
+    @MainActor
+    @discardableResult
+    func updating(instanceV2 instance: Mastodon.Entity.V2.Instance, for domain: String) -> Self {
+        authentications = authentications.map { authentication in
+            guard authentication.domain == domain else { return authentication }
+            return authentication.updating(instanceV2: instance)
+        }
+        return self
+    }
+
+    @MainActor
+    @discardableResult
+    func updating(translationLanguages: TranslationLanguages, for domain: String) -> Self {
         authentications = authentications.map { authentication in
             guard authentication.domain == domain else { return authentication }
-            return authentication.updating(instance: instance)
+            return authentication.updating(translationLanguages: translationLanguages)
         }
+        return self
     }
 
     func delete(authentication: MastodonAuthentication) throws {

MastodonSDK/Sources/MastodonCore/MastodonAuthentication.swift

@@ -5,6 +5,41 @@ import CoreDataStack
 import MastodonSDK
 
 public struct MastodonAuthentication: Codable, Hashable, UserIdentifier {
+    public enum InstanceConfiguration: Codable, Hashable {
+        case v1(Mastodon.Entity.Instance)
+        case v2(Mastodon.Entity.V2.Instance, TranslationLanguages)
+
+        public func canTranslateFrom(_ sourceLocale: String, to targetLanguage: String) -> Bool {
+            switch self {
+            case .v1:
+                return false
+            case let .v2(instance, translationLanguages):
+                guard instance.configuration?.translation?.enabled == true else { return false }
+                return translationLanguages[sourceLocale]?.contains(targetLanguage) == true
+            }
+        }
+
+        public var instanceConfigLimitingProperties: InstanceConfigLimitingPropertyContaining? {
+            switch self {
+            case let .v1(instance):
+                return instance.configuration
+            case let .v2(instance, _):
+                return instance.configuration
+            }
+        }
+
+        public var canFollowTags: Bool {
+            let version: String?
+            switch self {
+            case let .v1(instance):
+                version = instance.version
+            case let .v2(instance, _):
+                version = instance.version
+            }
+            return version?.majorServerVersion(greaterThanOrEquals: 4) ?? false // following Tags is support beginning with Mastodon v4.0.0
+        }
+    }
+
     public typealias ID = UUID
 
     public private(set) var identifier: ID
@@ -21,7 +56,8 @@ public struct MastodonAuthentication: Codable, Hashable, UserIdentifier {
     public private(set) var activedAt: Date
 
     public private(set) var userID: String
-    public private(set) var instanceObjectIdURI: URL?
+
+    public private(set) var instanceConfiguration: InstanceConfiguration?
 
     public var persistenceIdentifier: String {
         "\(username)@\(domain)"
@@ -49,7 +85,7 @@ public struct MastodonAuthentication: Codable, Hashable, UserIdentifier {
             updatedAt: now,
             activedAt: now,
             userID: userID,
-            instanceObjectIdURI: nil
+            instanceConfiguration: nil
         )
     }
 
@@ -65,7 +101,7 @@ public struct MastodonAuthentication: Codable, Hashable, UserIdentifier {
         updatedAt: Date? = nil,
         activedAt: Date? = nil,
         userID: String? = nil,
-        instanceObjectIdURI: URL? = nil
+        instanceConfiguration: InstanceConfiguration? = nil
     ) -> Self {
         MastodonAuthentication(
             identifier: identifier ?? self.identifier,
@@ -79,25 +115,9 @@ public struct MastodonAuthentication: Codable, Hashable, UserIdentifier {
             updatedAt: updatedAt ?? self.updatedAt,
             activedAt: activedAt ?? self.activedAt,
             userID: userID ?? self.userID,
-            instanceObjectIdURI: instanceObjectIdURI ?? self.instanceObjectIdURI
+            instanceConfiguration: instanceConfiguration ?? self.instanceConfiguration
         )
     }
-
-    public func instance(in context: NSManagedObjectContext) -> Instance? {
-        guard let instanceObjectIdURI,
-              let objectID = context.persistentStoreCoordinator?.managedObjectID(forURIRepresentation: instanceObjectIdURI)
-        else {
-            return nil
-        }
-
-        let instance = try? context.existingObject(with: objectID) as? Instance
-        return instance
-    }
-
-    public func user(in context: NSManagedObjectContext) -> MastodonUser? {
-        let userPredicate = MastodonUser.predicate(domain: domain, id: userID)
-        return MastodonUser.findOrFetch(in: context, matching: userPredicate)
-    }
 
     public func account() -> Mastodon.Entity.Account? {
 
@@ -113,8 +133,32 @@ public struct MastodonAuthentication: Codable, Hashable, UserIdentifier {
         MastodonUserIdentifier(domain: domain, userID: userID)
     }
 
-    func updating(instance: Instance) -> Self {
-        copy(instanceObjectIdURI: instance.objectID.uriRepresentation())
+    @MainActor
+    func updating(instanceV1 instance: Mastodon.Entity.Instance) -> Self {
+        return copy(instanceConfiguration: .v1(instance))
+    }
+
+    @MainActor
+    func updating(instanceV2 instance: Mastodon.Entity.V2.Instance) -> Self {
+        guard
+            let instanceConfiguration,
+            case let InstanceConfiguration.v2(_, translationLanguages) = instanceConfiguration
+        else {
+            return copy(instanceConfiguration: .v2(instance, [:]))
+        }
+        return copy(instanceConfiguration: .v2(instance, translationLanguages))
+    }
+
+    @MainActor
+    func updating(translationLanguages: TranslationLanguages) -> Self {
+        switch self.instanceConfiguration {
+        case .v1(let instance):
+            return copy(instanceConfiguration: .v1(instance))
+        case .v2(let instance, _):
+            return copy(instanceConfiguration: .v2(instance, translationLanguages))
+        case .none:
+            return self
+        }
     }
 
     func updating(activatedAt: Date) -> Self {