Indicate when an item is retrieving metadata

ZShare/ViewModels/ExtensionViewModel.swift

@@ -553,7 +553,7 @@ final class ExtensionViewModel {
                     case .recognitionInProgress, .remoteRecognitionInProgress, .identifierLookupInProgress:
                         updateState(with: .decoding)
 
-                    case .translated(item: let item):
+                    case .translated(let item):
                         var state = self.state
                         state.expectedItem = item
                         state.expectedAttachment = (filename, tmpFile)
@@ -562,7 +562,7 @@ final class ExtensionViewModel {
                         state.processedAttachment = .itemWithAttachment(item: item, attachment: [:], attachmentFile: file)
                         self.state = state
 
-                    case .createdParent:
+                    case .enqueued, .createdParent:
                         break
                     }
                 }

Zotero/Controllers/RecognizerController.swift

@@ -96,6 +96,7 @@ final class RecognizerController {
         enum Kind {
             case failed(Error)
             case cancelled
+            case enqueued
             case recognitionInProgress
             case remoteRecognitionInProgress(data: [String: Any])
             case identifierLookupInProgress(response: RemoteRecognizerResponse, identifier: String)
@@ -136,6 +137,7 @@ final class RecognizerController {
     // Accessed only via accessQueue
     private static let maxConcurrentRecognizerTasks: Int = 1
     private var queue: OrderedDictionary<RecognizerTask, (state: RecognizerTaskState, observable: PublishSubject<Update>)> = [:]
+    private var latestUpdates: [LibraryIdentifier: [String: Update.Kind]] = [:]
     private var lookupWebViewHandlersByRecognizerTask: [RecognizerTask: LookupWebViewHandler] = [:]
 
     // MARK: Object Lifecycle
@@ -163,28 +165,39 @@ final class RecognizerController {
     }
 
     // MARK: Actions
-    func queue(task: RecognizerTask, completion: @escaping (_ observable: Observable<Update>?) -> Void) {
+    func queue(task: RecognizerTask, completion: ((_ observable: Observable<Update>?) -> Void)? = nil) {
         accessQueue.async(flags: .barrier) { [weak self] in
             guard let self else {
-                completion(nil)
+                completion?(nil)
                 return
             }
             if let (_, observable) = queue[task] {
-                completion(observable.asObservable())
+                completion?(observable.asObservable())
                 return
             }
             let state: RecognizerTaskState = .enqueued
             let observable: PublishSubject<Update> = PublishSubject()
             queue[task] = (state, observable)
-            completion(observable.asObservable())
+            completion?(observable.asObservable())
             observable.subscribe(onNext: { [weak self] update in
                 self?.updatesSubject.on(.next(update))
             }).disposed(by: disposeBag)
 
+            emmitUpdate(for: task, observable: observable, kind: .enqueued)
             startRecognitionIfNeeded()
         }
     }
 
+    private func emmitUpdate(for task: RecognizerTask, observable: PublishSubject<Update>, kind: Update.Kind) {
+        let update = Update(task: task, kind: kind)
+        if case .createParentForItem(let libraryId, let key) = task.kind {
+            var libraryLatestUpdates = latestUpdates[libraryId, default: [:]]
+            libraryLatestUpdates[key] = kind
+            latestUpdates[libraryId] = libraryLatestUpdates
+        }
+        observable.on(.next(update))
+    }
+
     private func startRecognitionIfNeeded() {
         let runningRecognizerTasksCount = queue.filter({
             switch $0.value.state {
@@ -212,7 +225,7 @@ final class RecognizerController {
 
         func start(task: RecognizerTask, observable: PublishSubject<Update>) {
             queue[task] = (.recognitionInProgress, observable)
-            observable.on(.next(Update(task: task, kind: .recognitionInProgress)))
+            emmitUpdate(for: task, observable: observable, kind: .recognitionInProgress)
 
             pdfWorkerController.queue(work: PDFWorkerController.PDFWork(file: task.file, kind: .recognizer)) { [weak self] pdfWorkerObservable in
                 guard let self else { return }
@@ -266,7 +279,7 @@ final class RecognizerController {
                 return
             }
             queue[task] = (.remoteRecognitionInProgress(data: data), observable)
-            observable.on(.next(Update(task: task, kind: .remoteRecognitionInProgress(data: data))))
+            emmitUpdate(for: task, observable: observable, kind: .remoteRecognitionInProgress(data: data))
 
             apiClient.send(request: RecognizerRequest(parameters: data)).subscribe(
                 onSuccess: { (response: (RemoteRecognizerResponse, HTTPURLResponse)) in
@@ -378,7 +391,7 @@ final class RecognizerController {
                 enqueueNextIdentifierLookup(for: task)
                 return
             }
-            observable.on(.next(Update(task: task, kind: .identifierLookupInProgress(response: response, identifier: identifier))))
+            emmitUpdate(for: task, observable: observable, kind: .identifierLookupInProgress(response: response, identifier: identifier))
             lookupWebViewHandler.lookUp(identifier: identifier)
 
             func getLookupWebViewHandler(for task: RecognizerTask) -> LookupWebViewHandler? {
@@ -548,6 +561,10 @@ final class RecognizerController {
 
         func cleanup(for task: RecognizerTask, completion: @escaping (_ observable: PublishSubject<Update>?) -> Void) {
             let observable = queue.removeValue(forKey: task).flatMap({ $0.observable })
+            if case .createParentForItem(let libraryId, let key) = task.kind, var libraryLatestUpdates = latestUpdates[libraryId] {
+                libraryLatestUpdates[key] = nil
+                latestUpdates[libraryId] = libraryLatestUpdates
+            }
             DDLogInfo("RecognizerController: \(task) - cleaned up")
             if let webView = lookupWebViewHandlersByRecognizerTask.removeValue(forKey: task)?.webViewHandler.webView {
                 DispatchQueue.main.async {
@@ -558,4 +575,11 @@ final class RecognizerController {
             startRecognitionIfNeeded()
         }
     }
+
+    func latestUpdate(for key: String, libraryId: LibraryIdentifier) -> Update.Kind? {
+        return accessQueue.sync { [weak self] in
+            guard let self, let libraryLatestUpdates = latestUpdates[libraryId] else { return nil }
+            return libraryLatestUpdates[key]
+        }
+    }
 }

Zotero/Scenes/Detail/Items/Models/ItemCellModel.swift

@@ -17,25 +17,30 @@ struct ItemCellModel {
         case url
     }
 
+    struct Subtitle {
+        let text: String
+        let animated: Bool
+    }
+
     let key: String
     let typeIconName: String
     let iconRenderingMode: UIImage.RenderingMode
     let typeName: String
     let title: NSAttributedString
-    let subtitle: String
+    let subtitle: Subtitle?
     let hasNote: Bool
     let tagColors: [UIColor]
     let tagEmojis: [String]
     let accessory: Accessory?
     let hasDetailButton: Bool
 
-    init(item: RItem, typeName: String, title: NSAttributedString, accessory: Accessory?) {
+    init(item: RItem, typeName: String, title: NSAttributedString, subtitle: Subtitle?, accessory: Accessory?) {
         key = item.key
         typeIconName = Self.typeIconName(for: item)
         iconRenderingMode = .alwaysOriginal
         self.typeName = typeName
         self.title = title
-        subtitle = Self.creatorSummary(for: item)
+        self.subtitle = subtitle
         hasNote = Self.hasNote(item: item)
         self.accessory = accessory
         let (colors, emojis) = Self.tagData(item: item)
@@ -44,8 +49,14 @@ struct ItemCellModel {
         hasDetailButton = true
     }
 
-    init(item: RItem, typeName: String, title: NSAttributedString, accessory: ItemAccessory?, fileDownloader: AttachmentDownloader?) {
-        self.init(item: item, typeName: typeName, title: title, accessory: Self.createAccessory(from: accessory, fileDownloader: fileDownloader))
+    init(item: RItem, typeName: String, title: NSAttributedString, accessory: ItemAccessory?, fileDownloader: AttachmentDownloader?, recognizerController: RecognizerController?) {
+        self.init(
+            item: item,
+            typeName: typeName,
+            title: title,
+            subtitle: Self.createSubtitle(for: item, recognizerController: recognizerController),
+            accessory: Self.createAccessory(from: accessory, fileDownloader: fileDownloader)
+        )
     }
 
     init(collectionWithKey key: String, title: NSAttributedString) {
@@ -54,7 +65,7 @@ struct ItemCellModel {
         accessory = nil
         typeIconName = Asset.Images.Cells.collection.name
         iconRenderingMode = .alwaysTemplate
-        subtitle = ""
+        subtitle = nil
         hasNote = false
         tagColors = []
         tagEmojis = []
@@ -118,4 +129,31 @@ struct ItemCellModel {
         }
         return result
     }
+
+    static func createSubtitle(for item: RItem, update: RecognizerController.Update.Kind?) -> Subtitle? {
+        guard item.parent == nil, let update else {
+            return Subtitle(text: creatorSummary(for: item), animated: false)
+        }
+
+        let text: String
+        let animated: Bool
+        switch update {
+        case .failed, .cancelled, .createdParent:
+            text = creatorSummary(for: item)
+            animated = false
+
+        case .enqueued, .recognitionInProgress, .remoteRecognitionInProgress, .identifierLookupInProgress, .translated:
+            text = "Retrieving metadata"
+            animated = true
+        }
+        return Subtitle(text: text, animated: animated)
+    }
+
+    static func createSubtitle(for item: RItem, recognizerController: RecognizerController?) -> Subtitle? {
+        guard item.parent == nil, let recognizerController else {
+            return Subtitle(text: creatorSummary(for: item), animated: false)
+        }
+        let update = recognizerController.latestUpdate(for: item.key, libraryId: item.libraryIdentifier)
+        return createSubtitle(for: item, update: update)
+    }
 }

Zotero/Scenes/Detail/Items/Models/ItemsAction.swift

@@ -39,6 +39,7 @@ enum ItemsAction {
     case updateDownload(update: AttachmentDownloader.Update, batchData: ItemsState.DownloadBatchData?)
     case updateIdentifierLookup(update: IdentifierLookupController.Update, batchData: ItemsState.IdentifierLookupBatchData)
     case updateRemoteDownload(update: RemoteAttachmentDownloader.Update, batchData: ItemsState.DownloadBatchData?)
+    case updateMetadataRetrieval(itemKey: String, update: RecognizerController.Update.Kind)
     case openAttachment(attachment: Attachment, parentKey: String?)
     case attachmentOpened(String)
     case updateKeys(items: Results<RItem>, deletions: [Int], insertions: [Int], modifications: [Int])

Zotero/Scenes/Detail/Items/Models/ItemsState.swift

@@ -83,6 +83,16 @@ struct ItemsState: ViewModelState {
         }
     }
 
+    struct ItemUpdate {
+        enum Kind {
+            case accessory
+            case subtitle(ItemCellModel.Subtitle?)
+        }
+
+        let key: String
+        let kind: Kind
+    }
+
     let collection: Collection
 
     var library: Library
@@ -102,8 +112,8 @@ struct ItemsState: ViewModelState {
     var changes: Changes
     var error: ItemsError?
     var itemKeyToDuplicate: String?
-    // Used to indicate which row should update it's attachment view. The update is done directly to cell instead of tableView reload.
-    var updateItemKey: String?
+    // Used to indicate which row should update directly a cell element (e.g. attachment view). The update is done directly to cell instead of tableView reload.
+    var updateItem: ItemUpdate?
     var attachmentToOpen: String?
     var downloadBatchData: DownloadBatchData?
     var remoteDownloadBatchData: DownloadBatchData?
@@ -152,6 +162,6 @@ struct ItemsState: ViewModelState {
         error = nil
         changes = []
         itemKeyToDuplicate = nil
-        updateItemKey = nil
+        updateItem = nil
     }
 }

Zotero/Scenes/Detail/Items/ViewModels/ItemsActionHandler.swift

@@ -146,6 +146,9 @@ final class ItemsActionHandler: BaseItemsActionHandler, ViewModelActionHandler {
         case .updateRemoteDownload(let update, let batchData):
             self.process(remoteDownloadUpdate: update, batchData: batchData, in: viewModel)
 
+        case .updateMetadataRetrieval(let itemKey, let update):
+            process(metadataRetrievalUpdate: update, itemKey: itemKey, in: viewModel)
+
         case .openAttachment(let attachment, let parentKey):
             self.open(attachment: attachment, parentKey: parentKey, in: viewModel)
 
@@ -266,7 +269,7 @@ final class ItemsActionHandler: BaseItemsActionHandler, ViewModelActionHandler {
                   let updatedAccessory = accessory.updatedAttachment(update: { attachment in attachment.changed(location: .remote, condition: { $0 == .local }) }) else { return }
             self.update(viewModel: viewModel) { state in
                 state.itemAccessories[updateKey] = updatedAccessory
-                state.updateItemKey = updateKey
+                state.updateItem = ItemsState.ItemUpdate(key: updateKey, kind: .accessory)
             }
         }
     }
@@ -310,7 +313,7 @@ final class ItemsActionHandler: BaseItemsActionHandler, ViewModelActionHandler {
             guard let updatedAttachment = attachment.changed(location: .local, compressed: compressed) else { return }
             updateViewModel { state in
                 state.itemAccessories[updateKey] = .attachment(attachment: updatedAttachment, parentKey: downloadUpdate.parentKey)
-                state.updateItemKey = updateKey
+                state.updateItem = ItemsState.ItemUpdate(key: updateKey, kind: .accessory)
             }
 
         case .progress:
@@ -319,13 +322,13 @@ final class ItemsActionHandler: BaseItemsActionHandler, ViewModelActionHandler {
             guard let currentProgress = fileDownloader.data(for: downloadUpdate.key, parentKey: downloadUpdate.parentKey, libraryId: downloadUpdate.libraryId).progress, currentProgress < 1
             else { return }
             updateViewModel { state in
-                state.updateItemKey = updateKey
+                state.updateItem = ItemsState.ItemUpdate(key: updateKey, kind: .accessory)
             }
 
         case .cancelled, .failed:
             DDLogInfo("ItemsActionHandler: download update \(attachment.key); \(attachment.libraryId); kind \(downloadUpdate.kind)")
             updateViewModel { state in
-                state.updateItemKey = updateKey
+                state.updateItem = ItemsState.ItemUpdate(key: updateKey, kind: .accessory)
             }
         }
 
@@ -359,6 +362,13 @@ final class ItemsActionHandler: BaseItemsActionHandler, ViewModelActionHandler {
         }
     }
 
+    private func process(metadataRetrievalUpdate: RecognizerController.Update.Kind, itemKey: String, in viewModel: ViewModel<ItemsActionHandler>) {
+        guard let item = viewModel.state.results?.filter("key == %@", itemKey).first else { return }
+        update(viewModel: viewModel) { state in
+            state.updateItem = ItemsState.ItemUpdate(key: itemKey, kind: .subtitle(ItemCellModel.createSubtitle(for: item, update: metadataRetrievalUpdate)))
+        }
+    }
+
     private func cacheItemAccessory(for item: RItem, in viewModel: ViewModel<ItemsActionHandler>) {
         // Create cached accessory only if there is nothing in cache yet.
         guard viewModel.state.itemAccessories[item.key] == nil, let accessory = ItemAccessory.create(from: item, fileStorage: fileStorage, urlDetector: urlDetector) else { return }