use coredata to track pdf highlights

apple/OmnivoreKit/Sources/App/PDFSupport/PDFViewerViewModel.swift

@@ -41,7 +41,7 @@ public final class PDFViewerViewModel: ObservableObject {
     for highlight in fetchedHighlights {
       resultSet[highlight.id] = highlight
     }
-    for highlightId in services.dataService.fetchRemovedHighlightIds(pdfID: feedItem.id) {
+    for highlightId in services.dataService.deletedHighlightsIDs {
       resultSet.removeValue(forKey: highlightId)
     }
     return Array(resultSet.values)
@@ -164,6 +164,6 @@ public final class PDFViewerViewModel: ObservableObject {
   }
 
   private func removeLocalHighlights(highlightIds: [String]) {
-    services.dataService.removeHighlights(pdfID: feedItem.id, highlightIds: highlightIds)
+    services.dataService.removeHighlights(highlightIds: highlightIds)
   }
 }

apple/OmnivoreKit/Sources/Models/CoreData/CoreDataModel.xcdatamodeld/CoreDataModel.xcdatamodel/contents

@@ -3,6 +3,11 @@
     <entity name="PersistedArticleContent" representedClassName="PersistedArticleContent" syncable="YES" codeGenerationType="class">
         <attribute name="htmlContent" attributeType="String"/>
         <attribute name="slug" attributeType="String"/>
+        <uniquenessConstraints>
+            <uniquenessConstraint>
+                <constraint value="slug"/>
+            </uniquenessConstraint>
+        </uniquenessConstraints>
     </entity>
     <entity name="PersistedFeedItem" representedClassName="PersistedFeedItem" syncable="YES" codeGenerationType="class">
         <attribute name="author" optional="YES" attributeType="String"/>
@@ -22,6 +27,11 @@
         <attribute name="slug" attributeType="String"/>
         <attribute name="title" attributeType="String"/>
         <relationship name="labels" toMany="YES" deletionRule="Nullify" destinationEntity="PersistedFeedItemLabel"/>
+        <uniquenessConstraints>
+            <uniquenessConstraint>
+                <constraint value="id"/>
+            </uniquenessConstraint>
+        </uniquenessConstraints>
     </entity>
     <entity name="PersistedFeedItemLabel" representedClassName="PersistedFeedItemLabel" syncable="YES" codeGenerationType="class">
         <attribute name="color" attributeType="String"/>
@@ -29,23 +39,35 @@
         <attribute name="id" attributeType="String"/>
         <attribute name="labelDescription" optional="YES" attributeType="String"/>
         <attribute name="name" attributeType="String"/>
+        <uniquenessConstraints>
+            <uniquenessConstraint>
+                <constraint value="id"/>
+            </uniquenessConstraint>
+        </uniquenessConstraints>
     </entity>
     <entity name="PersistedHighlight" representedClassName="PersistedHighlight" syncable="YES" codeGenerationType="class">
         <attribute name="annotation" optional="YES" attributeType="String"/>
+        <attribute name="associatedItemId" attributeType="String"/>
         <attribute name="createdAt" optional="YES" attributeType="Date" usesScalarValueType="NO"/>
         <attribute name="createdByMe" attributeType="Boolean" usesScalarValueType="YES"/>
         <attribute name="id" attributeType="String"/>
+        <attribute name="markedForDeletion" attributeType="Boolean" defaultValueString="NO" usesScalarValueType="YES"/>
         <attribute name="patch" attributeType="String"/>
         <attribute name="prefix" optional="YES" attributeType="String"/>
         <attribute name="quote" attributeType="String"/>
         <attribute name="shortId" attributeType="String"/>
         <attribute name="suffix" optional="YES" attributeType="String"/>
         <attribute name="updatedAt" optional="YES" attributeType="Date" usesScalarValueType="NO"/>
+        <uniquenessConstraints>
+            <uniquenessConstraint>
+                <constraint value="id"/>
+            </uniquenessConstraint>
+        </uniquenessConstraints>
     </entity>
     <elements>
         <element name="PersistedFeedItemLabel" positionX="-36" positionY="18" width="128" height="104"/>
         <element name="PersistedFeedItem" positionX="-18" positionY="63" width="128" height="284"/>
         <element name="PersistedArticleContent" positionX="9" positionY="108" width="128" height="59"/>
-        <element name="PersistedHighlight" positionX="27" positionY="225" width="128" height="14"/>
+        <element name="PersistedHighlight" positionX="27" positionY="225" width="128" height="209"/>
     </elements>
 </model>

apple/OmnivoreKit/Sources/Models/Highlight.swift

@@ -1,3 +1,4 @@
+import CoreData
 import Foundation
 
 public struct Highlight: Identifiable, Hashable, Codable {
@@ -35,4 +36,36 @@ public struct Highlight: Identifiable, Hashable, Codable {
     self.updatedAt = updatedAt
     self.createdByMe = createdByMe
   }
+
+  public func toManagedObject(context: NSManagedObjectContext, associatedItemID: String) -> PersistedHighlight {
+    let persistedHighlight = PersistedHighlight(context: context)
+    persistedHighlight.associatedItemId = associatedItemID
+    persistedHighlight.markedForDeletion = false
+    persistedHighlight.id = id
+    persistedHighlight.shortId = shortId
+    persistedHighlight.quote = quote
+    persistedHighlight.prefix = prefix
+    persistedHighlight.suffix = suffix
+    persistedHighlight.patch = patch
+    persistedHighlight.annotation = annotation
+    persistedHighlight.createdAt = createdAt
+    persistedHighlight.updatedAt = updatedAt
+    persistedHighlight.createdByMe = createdByMe
+    return persistedHighlight
+  }
+
+  public static func make(from persistedHighlight: PersistedHighlight) -> Highlight {
+    Highlight(
+      id: persistedHighlight.id ?? "",
+      shortId: persistedHighlight.shortId ?? "",
+      quote: persistedHighlight.quote ?? "",
+      prefix: persistedHighlight.prefix,
+      suffix: persistedHighlight.suffix,
+      patch: persistedHighlight.patch ?? "",
+      annotation: persistedHighlight.annotation,
+      createdByMe: persistedHighlight.createdByMe,
+      createdAt: persistedHighlight.createdAt,
+      updatedAt: persistedHighlight.updatedAt
+    )
+  }
 }

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

@@ -11,11 +11,9 @@ public final class DataService: ObservableObject {
   public internal(set) var currentViewer: Viewer?
   let networker: Networker
 
-  let highlightsCache = NSCache<AnyObject, CachedPDFHighlights>()
-  let highlightsCacheQueue = DispatchQueue(label: "app.omnivore.highlights.cache.queue", attributes: .concurrent)
-
   let persistentContainer: PersistentContainer
   var subscriptions = Set<AnyCancellable>()
+  public var deletedHighlightsIDs = Set<String>()
 
   public init(appEnvironment: AppEnvironment, networker: Networker) {
     self.appEnvironment = appEnvironment
@@ -30,7 +28,21 @@ public final class DataService: ObservableObject {
   }
 
   public func clearHighlights() {
-    highlightsCache.removeAllObjects()
+    deletedHighlightsIDs.removeAll()
+
+    let fetchRequest: NSFetchRequest<Models.PersistedHighlight> = PersistedHighlight.fetchRequest()
+
+    let highlights = (try? persistentContainer.viewContext.fetch(fetchRequest)) ?? []
+
+    for highlight in highlights {
+      persistentContainer.viewContext.delete(highlight)
+    }
+
+    do {
+      try persistentContainer.viewContext.save()
+    } catch {
+      print("failed to delete objects")
+    }
   }
 
   public func switchAppEnvironment(appEnvironment: AppEnvironment) {

apple/OmnivoreKit/Sources/Services/Persistence/PersistableModels/CachedPDFHighlights.swift

@@ -1,57 +1,53 @@
 import Combine
+import CoreData
 import Foundation
 import Models
 
-final class CachedPDFHighlights {
-  init(pdfID: String, highlights: [Highlight], removedHighlightIDs: [String]) {
-    self.pdfID = pdfID
-    self.highlights = highlights
-    self.removedHighlightIDs = removedHighlightIDs
-  }
-
-  let pdfID: String
-  var highlights: [Highlight]
-  var removedHighlightIDs: [String]
-}
-
 public extension DataService {
   func cachedHighlights(pdfID: String) -> [Highlight] {
-    fetchCachedHighlights(pdfID: pdfID as NSString)?.highlights ?? []
-  }
+    let fetchRequest: NSFetchRequest<Models.PersistedHighlight> = PersistedHighlight.fetchRequest()
+    fetchRequest.predicate = NSPredicate(
+      format: "associatedItemId = %@ AND markedForDeletion = %@", pdfID, false
+    )
 
-  func fetchRemovedHighlightIds(pdfID: String) -> [String] {
-    fetchCachedHighlights(pdfID: pdfID as NSString)?.removedHighlightIDs ?? []
+    let highlights = (try? persistentContainer.viewContext.fetch(fetchRequest)) ?? []
+    return highlights.map { Highlight.make(from: $0) }
   }
 
   func persistHighlight(pdfID: String, highlight: Highlight) {
-    let cachedHighlights =
-      fetchCachedHighlights(pdfID: pdfID as NSString)
-        ?? CachedPDFHighlights(pdfID: pdfID, highlights: [], removedHighlightIDs: [])
+    _ = highlight.toManagedObject(
+      context: persistentContainer.viewContext,
+      associatedItemID: pdfID
+    )
 
-    cachedHighlights.highlights.append(highlight)
-    insertCachedHighlights(highlights: cachedHighlights, pdfID: pdfID as NSString)
-  }
-
-  func removeHighlights(pdfID: String, highlightIds: [String]) {
-    let cachedHighlights =
-      fetchCachedHighlights(pdfID: pdfID as NSString)
-        ?? CachedPDFHighlights(pdfID: pdfID, highlights: [], removedHighlightIDs: [])
-
-    cachedHighlights.removedHighlightIDs.append(contentsOf: highlightIds)
-    insertCachedHighlights(highlights: cachedHighlights, pdfID: pdfID as NSString)
-  }
-
-  private func fetchCachedHighlights(pdfID: NSString) -> CachedPDFHighlights? {
-    var cachedHighlights: CachedPDFHighlights?
-    highlightsCacheQueue.sync {
-      cachedHighlights = highlightsCache.object(forKey: pdfID as NSString)
+    do {
+      try persistentContainer.viewContext.save()
+      print("PersistedHighlight saved succesfully")
+    } catch {
+      persistentContainer.viewContext.rollback()
+      print("Failed to save PersistedHighlight: \(error)")
     }
-    return cachedHighlights
   }
 
-  private func insertCachedHighlights(highlights: CachedPDFHighlights, pdfID: NSString) {
-    highlightsCacheQueue.async(flags: .barrier) {
-      self.highlightsCache.setObject(highlights, forKey: pdfID as AnyObject)
+  func removeHighlights(highlightIds: [String]) {
+    for highlightID in highlightIds {
+      deletedHighlightsIDs.insert(highlightID)
+    }
+
+    let fetchRequest: NSFetchRequest<Models.PersistedHighlight> = PersistedHighlight.fetchRequest()
+    fetchRequest.predicate = NSPredicate(format: "id IN %@", highlightIds)
+    guard let highlights = try? persistentContainer.viewContext.fetch(fetchRequest) else { return }
+
+    for highlight in highlights {
+      highlight.markedForDeletion = true
+    }
+
+    do {
+      try persistentContainer.viewContext.save()
+      print("PersistedHighlight(s) updated succesfully")
+    } catch {
+      persistentContainer.viewContext.rollback()
+      print("Failed to update PersistedHighlight(s): \(error)")
     }
   }
 }