create a InternalLinkedItem model

apple/OmnivoreKit/Sources/Services/DataService/Mutations/UpdateArticleReadingProgress.swift

@@ -50,6 +50,7 @@ public extension DataService {
 
             switch payload.data {
             case let .saved(feedItem):
+              // TODO: update core data record
               promise(.success(feedItem))
             case let .error(errorCode: errorCode):
               switch errorCode {

apple/OmnivoreKit/Sources/Services/InternalModels/InternalLinkedItem.swift

@@ -0,0 +1,90 @@
+import CoreData
+import Foundation
+import Models
+
+struct InternalLinkedItem {
+  let id: String
+  let title: String
+  let createdAt: Date
+  let savedAt: Date
+  var readingProgress: Double
+  var readingProgressAnchor: Int
+  let imageURLString: String?
+  let onDeviceImageURLString: String?
+  let documentDirectoryPath: String?
+  let pageURLString: String
+  let descriptionText: String?
+  let publisherURLString: String?
+  let author: String?
+  let publishDate: Date?
+  let slug: String
+  let isArchived: Bool
+  let contentReader: String?
+  var labels: [FeedItemLabelDep]
+
+  func asManagedObject(inContext context: NSManagedObjectContext) -> LinkedItem {
+    let linkedItem = LinkedItem(entity: LinkedItem.entity(), insertInto: context)
+
+    linkedItem.id = id
+    linkedItem.title = title
+    linkedItem.createdAt = createdAt
+    linkedItem.savedAt = savedAt
+    linkedItem.readingProgress = readingProgress
+    linkedItem.readingProgressAnchor = Int64(readingProgressAnchor)
+    linkedItem.imageURLString = imageURLString
+    linkedItem.onDeviceImageURLString = onDeviceImageURLString
+    linkedItem.pageURLString = pageURLString
+    linkedItem.descriptionText = descriptionText
+    linkedItem.publisherURLString = publisherURLString
+    linkedItem.author = author
+    linkedItem.publishDate = publishDate
+    linkedItem.slug = slug
+    linkedItem.isArchived = isArchived
+    linkedItem.contentReader = contentReader
+
+    //    for label in item.labels {
+    // TODO: append labels
+    //    }
+
+    return linkedItem
+  }
+
+  static func make(from item: LinkedItem) -> InternalLinkedItem {
+    InternalLinkedItem(
+      id: item.id ?? "",
+      title: item.title ?? "",
+      createdAt: item.createdAt ?? Date(),
+      savedAt: item.savedAt ?? Date(),
+      readingProgress: item.readingProgress,
+      readingProgressAnchor: Int(item.readingProgressAnchor),
+      imageURLString: item.imageURLString,
+      onDeviceImageURLString: item.onDeviceImageURLString,
+      documentDirectoryPath: nil,
+      pageURLString: item.pageURLString ?? "",
+      descriptionText: item.title,
+      publisherURLString: item.publisherURLString,
+      author: item.author,
+      publishDate: item.publishDate,
+      slug: item.slug ?? "",
+      isArchived: item.isArchived,
+      contentReader: item.contentReader,
+      labels: []
+    )
+  }
+}
+
+extension Sequence where Element == InternalLinkedItem {
+  func persist(context: NSManagedObjectContext) -> [LinkedItem]? {
+    let linkedItems = map { $0.asManagedObject(inContext: context) }
+
+    do {
+      try context.save()
+      print("LinkedItems saved succesfully")
+      return linkedItems
+    } catch {
+      context.rollback()
+      print("Failed to save LinkedItems: \(error.localizedDescription)")
+      return nil
+    }
+  }
+}