Add server-provided translation

Closes #331

Packages/Pachyderm/Sources/Pachyderm/Model/Status.swift

@@ -177,6 +177,10 @@ public final class Status: StatusProtocol, Decodable, Sendable {
         return Request(method: .get, path: "/api/v1/statuses/\(statusID)/history")
     }
     
+    public static func translate(_ statusID: String) -> Request<Translation> {
+        return Request(method: .post, path: "/api/v1/statuses/\(statusID)/translate")
+    }
+    
     private enum CodingKeys: String, CodingKey {
         case id
         case uri

Packages/Pachyderm/Sources/Pachyderm/Model/Translation.swift

@@ -0,0 +1,22 @@
+//
+//  Translation.swift
+//  Pachyderm
+//
+//  Created by Shadowfacts on 12/4/23.
+//
+
+import Foundation
+
+public struct Translation: Decodable, Sendable {
+    public let content: String
+    public let spoilerText: String?
+    public let detectedSourceLanguage: String
+    public let provider: String
+    
+    private enum CodingKeys: String, CodingKey {
+        case content
+        case spoilerText
+        case detectedSourceLanguage = "detected_source_language"
+        case provider
+    }
+}

Tusker/CoreData/StatusMO.swift

@@ -54,6 +54,7 @@ public final class StatusMO: NSManagedObject, StatusProtocol {
     @NSManaged public var reblog: StatusMO?
     @NSManaged public var localOnly: Bool
     @NSManaged public var lastFetchedAt: Date?
+    @NSManaged public var language: String?
     
     @LazilyDecoding(arrayFrom: \StatusMO.attachmentsData)
     public var attachments: [Attachment]
@@ -139,6 +140,7 @@ extension StatusMO {
         self.visibility = status.visibility
         self.poll = status.poll
         self.localOnly = status.localOnly ?? false
+        self.language = status.language
         
         if let existing = container.account(for: status.account.id, in: context) {
             existing.updateFrom(apiAccount: status.account, container: container)

Tusker/CoreData/Tusker.xcdatamodeld/Tusker.xcdatamodel/contents

@@ -110,6 +110,7 @@
         <attribute name="id" attributeType="String"/>
         <attribute name="inReplyToAccountID" optional="YES" attributeType="String"/>
         <attribute name="inReplyToID" optional="YES" attributeType="String"/>
+        <attribute name="language" optional="YES" attributeType="String"/>
         <attribute name="lastFetchedAt" optional="YES" attributeType="Date" usesScalarValueType="NO"/>
         <attribute name="localOnly" attributeType="Boolean" defaultValueString="NO" usesScalarValueType="YES"/>
         <attribute name="mentionsData" attributeType="Binary"/>

Tusker/Screens/Conversation/ConversationCollectionViewController.swift

@@ -15,6 +15,7 @@ class ConversationCollectionViewController: UIViewController, CollectionViewCont
     private let mastodonController: MastodonController
     private let mainStatusID: String
     private let mainStatusState: CollapseState
+    private var mainStatusTranslation: Translation?
     var statusIDToScrollToOnLoad: String
     var showStatusesAutomatically = false
     
@@ -88,11 +89,14 @@ class ConversationCollectionViewController: UIViewController, CollectionViewCont
             cell.updateUI(statusID: item.0, state: item.1, filterResult: .allow, precomputedContent: nil)
             cell.setShowThreadLinks(prev: item.2, next: item.3)
         }
-        let mainStatusCell = UICollectionView.CellRegistration<ConversationMainStatusCollectionViewCell, (String, CollapseState, Bool)> { [unowned self] cell, indexPath, item in
+        let mainStatusCell = UICollectionView.CellRegistration<ConversationMainStatusCollectionViewCell, (String, CollapseState, Translation?, Bool)> { [unowned self] cell, indexPath, item in
             cell.delegate = self
+            cell.translateStatus = { [unowned self] in
+                self.translateMainStatus()
+            }
             cell.showStatusAutomatically = self.showStatusesAutomatically
-            cell.updateUI(statusID: item.0, state: item.1)
+            cell.updateUI(statusID: item.0, state: item.1, translation: item.2)
-            cell.setShowThreadLinks(prev: item.2, next: false)
+            cell.setShowThreadLinks(prev: item.3, next: false)
         }
         let expandThreadCell = UICollectionView.CellRegistration<ExpandThreadCollectionViewCell, ([ConversationNode], Bool)> { cell, indexPath, item in
             cell.updateUI(childThreads: item.0, inline: item.1)
@@ -104,7 +108,7 @@ class ConversationCollectionViewController: UIViewController, CollectionViewCont
             switch itemIdentifier {
             case let .status(id: id, node: _, state: state, prevLink: prevLink, nextLink: nextLink):
                 if id == self.mainStatusID {
-                    return collectionView.dequeueConfiguredReusableCell(using: mainStatusCell, for: indexPath, item: (id, state, prevLink))
+                    return collectionView.dequeueConfiguredReusableCell(using: mainStatusCell, for: indexPath, item: (id, state, self.mainStatusTranslation, prevLink))
                 } else {
                     return collectionView.dequeueConfiguredReusableCell(using: statusCell, for: indexPath, item: (id, state, prevLink, nextLink))
                 }
@@ -260,6 +264,30 @@ class ConversationCollectionViewController: UIViewController, CollectionViewCont
         }
     }
     
+    private func translateMainStatus() {
+        Task { @MainActor in
+            let translation: Translation
+            do {
+                translation = try await mastodonController.run(Status.translate(mainStatusID)).0
+            } catch {
+                let config = ToastConfiguration(from: error, with: "Error Translating", in: self) { toast in
+                    toast.dismissToast(animated: true)
+                    self.translateMainStatus()
+                }
+                self.showToast(configuration: config, animated: true)
+                return
+            }
+            
+            mainStatusTranslation = translation
+            
+            var snapshot = dataSource.snapshot()
+            snapshot.reconfigureItems(snapshot.itemIdentifiers(inSection: .mainStatus))
+            await MainActor.run {
+                dataSource.apply(snapshot, animatingDifferences: true)
+            }
+        }
+    }
+    
 }
 
 extension ConversationCollectionViewController {

Tusker/Views/Attachments/AttachmentsContainerView.swift

@@ -80,6 +80,7 @@ class AttachmentsContainerView: UIView {
         }
         
         guard self.attachmentTokens != newTokens else {
+            self.isHidden = attachments.isEmpty
             return
         }
         

Tusker/Views/ContentTextView.swift

@@ -23,7 +23,7 @@ class ContentTextView: LinkTextView, BaseEmojiLabel {
     weak var overrideMastodonController: MastodonController?
     var mastodonController: MastodonController? { overrideMastodonController ?? navigationDelegate?.apiController }
 
-    private var htmlConverter = HTMLConverter()
+    private(set) var htmlConverter = HTMLConverter()
     var defaultFont: UIFont {
         _read { yield htmlConverter.font }
         _modify { yield &htmlConverter.font }

Tusker/Views/Status/ConversationMainStatusCollectionViewCell.swift

@@ -141,6 +141,8 @@ class ConversationMainStatusCollectionViewCell: UICollectionViewListCell, Status
         }
     }
     
+    private var translateButton: TranslateButton?
+    
     let cardView = StatusCardView().configure {
         $0.heightAnchor.constraint(equalToConstant: StatusContentContainer.cardViewHeight).isActive = true
     }
@@ -309,6 +311,7 @@ class ConversationMainStatusCollectionViewCell: UICollectionViewListCell, Status
     var mastodonController: MastodonController! { delegate?.apiController }
     weak var delegate: StatusCollectionViewCellDelegate?
     var showStatusAutomatically = false
+    var translateStatus: (() -> Void)?
     
     var statusID: String!
     var statusState: CollapseState!
@@ -368,7 +371,7 @@ class ConversationMainStatusCollectionViewCell: UICollectionViewListCell, Status
     
     // MARK: Configure UI
     
-    func updateUI(statusID: String, state: CollapseState) {
+    func updateUI(statusID: String, state: CollapseState, translation: Translation?) {
         guard let status = mastodonController.persistentContainer.status(for: statusID) else {
             fatalError()
         }
@@ -378,7 +381,17 @@ class ConversationMainStatusCollectionViewCell: UICollectionViewListCell, Status
         self.statusID = statusID
         self.statusState = state
         
-        doUpdateUI(status: status)
+        let attributedTranslatedContent: NSAttributedString? = translation.map {
+            contentTextView.htmlConverter.convert($0.content)
+        }
+        doUpdateUI(status: status, precomputedContent: attributedTranslatedContent)
+        
+        if !status.spoilerText.isEmpty,
+           let translated = translation?.spoilerText {
+            contentWarningLabel.text = translated
+            contentWarningLabel.setEmojis(status.emojis, identifier: "\(statusID)_translated")
+        }
+        
         accountDetailToContentWarningSpacer.isHidden = collapseButton.isHidden
         contentWarningToCollapseButtonSpacer.isHidden = collapseButton.isHidden
         
@@ -403,6 +416,31 @@ class ConversationMainStatusCollectionViewCell: UICollectionViewListCell, Status
         } else {
             editTimestampButton.isHidden = true
         }
+        
+        if mastodonController.instanceFeatures.translation,
+           let preferredLanguage = mastodonController.accountPreferences.serverDefaultLanguage,
+           preferredLanguage != status.language {
+            var config = UIButton.Configuration.tinted()
+                config.image = UIImage(systemName: "globe")!
+            if let translation {
+                let lang = Locale.current.localizedString(forLanguageCode: translation.detectedSourceLanguage) ?? translation.detectedSourceLanguage
+                config.title = "Translated from \(lang)"
+            } else {
+                config.title = "Translate"
+            }
+            
+            if let translateButton {
+                translateButton.configuration = config
+            } else {
+                let button = TranslateButton(configuration: config)
+                button.addTarget(self, action: #selector(translatePressed), for: .touchUpInside)
+                translateButton = button
+                contentContainer.insertArrangedSubview(button, after: contentTextView)
+            }
+            translateButton!.isEnabled = translation == nil
+        } else if let translateButton {
+            contentContainer.removeArrangedSubview(translateButton)
+        }
     }
     
     private func createObservers() {
@@ -507,6 +545,10 @@ class ConversationMainStatusCollectionViewCell: UICollectionViewListCell, Status
         delegate?.show(StatusEditHistoryViewController(statusID: statusID, mastodonController: mastodonController), sender: nil)
     }
     
+    @objc private func translatePressed() {
+        translateStatus?()
+    }
+    
 }
 
 private class ConversationMainStatusAccountDetailAccessibilityElement: UIAccessibilityElement {
@@ -575,3 +617,13 @@ extension ConversationMainStatusCollectionViewCell: UIPointerInteractionDelegate
         return nil
     }
 }
+
+private class TranslateButton: UIButton, StatusContentView {
+    var statusContentFillsHorizontally: Bool {
+        false
+    }
+    
+    func estimateHeight(effectiveWidth: CGFloat) -> CGFloat {
+        0
+    }
+}

Tusker/Views/Status/StatusContentContainer.swift

@@ -12,7 +12,7 @@ class StatusContentContainer: UIView {
     // TODO: this is a weird place for this
     static var cardViewHeight: CGFloat { 90 }
     
-    private let arrangedSubviews: [any StatusContentView]
+    private var arrangedSubviews: [any StatusContentView]
     
     private var isHiddenObservations: [NSKeyValueObservation] = []
     
@@ -40,10 +40,14 @@ class StatusContentContainer: UIView {
             subview.translatesAutoresizingMaskIntoConstraints = false
             addSubview(subview)
             
-            NSLayoutConstraint.activate([
+            if subview.statusContentFillsHorizontally {
-                subview.leadingAnchor.constraint(equalTo: leadingAnchor),
+                NSLayoutConstraint.activate([
-                subview.trailingAnchor.constraint(equalTo: trailingAnchor),
+                    subview.leadingAnchor.constraint(equalTo: leadingAnchor),
-            ])
+                    subview.trailingAnchor.constraint(equalTo: trailingAnchor),
+                ])
+            } else {
+                subview.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
+            }
         }
         
         // this constraint needs to have low priority so that during the collapse/expand animation, the content container is the view that shrinks/expands
@@ -52,6 +56,14 @@ class StatusContentContainer: UIView {
         
         setNeedsUpdateConstraints()
                 
+        updateObservations()
+    }
+    
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+    
+    private func updateObservations() {
         isHiddenObservations = arrangedSubviews.map {
             $0.observeIsHidden { [unowned self] in
                 self.setNeedsUpdateConstraints()
@@ -59,10 +71,6 @@ class StatusContentContainer: UIView {
         }
     }
     
-    required init?(coder: NSCoder) {
-        fatalError("init(coder:) has not been implemented")
-    }
-    
     override func updateConstraints() {
         let visibleSubviews = IndexSet(arrangedSubviews.indices.filter { !arrangedSubviews[$0].isHidden })
         if self.visibleSubviews != visibleSubviews {
@@ -99,6 +107,31 @@ class StatusContentContainer: UIView {
         super.updateConstraints()
     }
     
+    func insertArrangedSubview(_ view: any StatusContentView, after: any StatusContentView) {
+        view.translatesAutoresizingMaskIntoConstraints = false
+        addSubview(view)
+        if view.statusContentFillsHorizontally {
+            NSLayoutConstraint.activate([
+                view.leadingAnchor.constraint(equalTo: leadingAnchor),
+                view.trailingAnchor.constraint(equalTo: trailingAnchor),
+            ])
+        } else {
+            view.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
+        }
+        
+        let index = arrangedSubviews.firstIndex(where: { $0 === after })!
+        arrangedSubviews.insert(view, at: index + 1)
+        setNeedsUpdateConstraints()
+        updateObservations()
+    }
+    
+    func removeArrangedSubview(_ view: any StatusContentView) {
+        view.removeFromSuperview()
+        arrangedSubviews.removeAll(where: { $0 === view })
+        setNeedsUpdateConstraints()
+        updateObservations()
+    }
+    
     func setCollapsed(_ collapsed: Bool) {
         guard collapsed != isCollapsed else {
             return
@@ -154,9 +187,16 @@ private extension UIView {
 }
 
 protocol StatusContentView: UIView {
+    var statusContentFillsHorizontally: Bool { get }
     func estimateHeight(effectiveWidth: CGFloat) -> CGFloat
 }
 
+extension StatusContentView {
+    var statusContentFillsHorizontally: Bool {
+        true
+    }
+}
+
 extension ContentTextView: StatusContentView {
     func estimateHeight(effectiveWidth: CGFloat) -> CGFloat {
         sizeThatFits(CGSize(width: effectiveWidth, height: UIView.layoutFittingCompressedSize.height)).height