fix: Core Data threading and network error handling

- Add thread-safe NSManagedObjectContext extension
- Fix EXC_BAD_ACCESS with performAndWait wrappers
- Add network error detection with retry functionality
- Change hero image to aspectFill for better layout
- Mark classes as @unchecked Sendable for Swift Concurrency

URLShare/OfflineBookmarkManager.swift

@@ -1,7 +1,7 @@
 import Foundation
 import CoreData
 
-class OfflineBookmarkManager {
+class OfflineBookmarkManager: @unchecked Sendable {
     static let shared = OfflineBookmarkManager()
     
     private init() {}
@@ -17,27 +17,31 @@ class OfflineBookmarkManager {
     func saveOfflineBookmark(url: String, title: String = "", tags: [String] = []) -> Bool {
         let tagsString = tags.joined(separator: ",")
         
+        do {
+            try context.safePerform { [weak self] in
+                guard let self = self else { return }
+                
                 // Check if URL already exists offline
                 let fetchRequest: NSFetchRequest<ArticleURLEntity> = ArticleURLEntity.fetchRequest()
                 fetchRequest.predicate = NSPredicate(format: "url == %@", url)
                 
-        do {
+                let existingEntities = try self.context.fetch(fetchRequest)
-            let existingEntities = try context.fetch(fetchRequest)
                 if let existingEntity = existingEntities.first {
                     // Update existing entry
                     existingEntity.tags = tagsString
                     existingEntity.title = title
                 } else {
                     // Create new entry
-                let entity = ArticleURLEntity(context: context)
+                    let entity = ArticleURLEntity(context: self.context)
                     entity.id = UUID()
                     entity.url = url
                     entity.title = title
                     entity.tags = tagsString
                 }
                 
-            try context.save()
+                try self.context.save()
                 print("Bookmark saved offline: \(url)")
+            }
             return true
         } catch {
             print("Failed to save offline bookmark: \(error)")
@@ -46,11 +50,14 @@ class OfflineBookmarkManager {
     }
     
     func getTags() -> [String] {
-        let fetchRequest: NSFetchRequest<TagEntity> = TagEntity.fetchRequest()
-        
         do {
-            let tagEntities = try context.fetch(fetchRequest)
+            return try context.safePerform { [weak self] in
+                guard let self = self else { return [] }
+                
+                let fetchRequest: NSFetchRequest<TagEntity> = TagEntity.fetchRequest()
+                let tagEntities = try self.context.fetch(fetchRequest)
                 return tagEntities.compactMap { $0.name }.sorted()
+            }
         } catch {
             print("Failed to fetch tags: \(error)")
             return []

readeck.xcodeproj/project.pbxproj

@@ -81,6 +81,7 @@
 			membershipExceptions = (
 				Assets.xcassets,
 				Data/CoreData/CoreDataManager.swift,
+				"Data/Extensions/NSManagedObjectContext+SafeFetch.swift",
 				Data/KeychainHelper.swift,
 				Domain/Model/Bookmark.swift,
 				Domain/Model/BookmarkLabel.swift,
@@ -435,7 +436,7 @@
 			buildSettings = {
 				CODE_SIGN_ENTITLEMENTS = URLShare/URLShare.entitlements;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 21;
+				CURRENT_PROJECT_VERSION = 22;
 				DEVELOPMENT_TEAM = 8J69P655GN;
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_FILE = URLShare/Info.plist;
@@ -468,7 +469,7 @@
 			buildSettings = {
 				CODE_SIGN_ENTITLEMENTS = URLShare/URLShare.entitlements;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 21;
+				CURRENT_PROJECT_VERSION = 22;
 				DEVELOPMENT_TEAM = 8J69P655GN;
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_FILE = URLShare/Info.plist;
@@ -623,7 +624,7 @@
 				CODE_SIGN_ENTITLEMENTS = readeck/readeck.entitlements;
 				CODE_SIGN_IDENTITY = "Apple Development";
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 21;
+				CURRENT_PROJECT_VERSION = 22;
 				DEVELOPMENT_ASSET_PATHS = "\"readeck/Preview Content\"";
 				DEVELOPMENT_TEAM = 8J69P655GN;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -667,7 +668,7 @@
 				CODE_SIGN_ENTITLEMENTS = readeck/readeck.entitlements;
 				CODE_SIGN_IDENTITY = "Apple Development";
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 21;
+				CURRENT_PROJECT_VERSION = 22;
 				DEVELOPMENT_ASSET_PATHS = "\"readeck/Preview Content\"";
 				DEVELOPMENT_TEAM = 8J69P655GN;
 				ENABLE_HARDENED_RUNTIME = YES;

readeck/Data/Extensions/NSManagedObjectContext+SafeFetch.swift

@@ -0,0 +1,77 @@
+//
+//  NSManagedObjectContext+SafeFetch.swift
+//  readeck
+//
+//  Created by Ilyas Hallak on 25.07.25.
+//
+//  SPDX-License-Identifier: MIT
+//
+//  This file is part of the readeck project and is licensed under the MIT License.
+//
+
+import CoreData
+import Foundation
+
+extension NSManagedObjectContext {
+    
+    /// Thread-safe fetch that automatically wraps the operation in performAndWait
+    func safeFetch<T: NSManagedObject>(_ request: NSFetchRequest<T>) throws -> [T] {
+        var results: [T] = []
+        var fetchError: Error?
+        
+        performAndWait {
+            do {
+                results = try self.fetch(request)
+            } catch {
+                fetchError = error
+            }
+        }
+        
+        if let error = fetchError {
+            throw error
+        }
+        
+        return results
+    }
+    
+    /// Thread-safe perform operation with return value
+    func safePerform<T>(_ operation: @escaping @Sendable () throws -> T) throws -> T {
+        var result: T?
+        var operationError: Error?
+        
+        performAndWait {
+            do {
+                result = try operation()
+            } catch {
+                operationError = error
+            }
+        }
+        
+        if let error = operationError {
+            throw error
+        }
+        
+        guard let unwrappedResult = result else {
+            throw NSError(domain: "SafePerformError", code: -1, userInfo: [NSLocalizedDescriptionKey: "Operation returned nil"])
+        }
+        
+        return unwrappedResult
+    }
+    
+    /// Thread-safe perform operation without return value
+    func safePerform(_ operation: @escaping () throws -> Void) throws {
+        var operationError: Error?
+        
+        performAndWait {
+            do {
+                try operation()
+            } catch {
+                operationError = error
+            }
+        }
+        
+        if let error = operationError {
+            throw error
+        }
+    }
+}

readeck/Data/Repository/OfflineSyncManager.swift

@@ -2,7 +2,7 @@ import Foundation
 import CoreData
 import SwiftUI
 
-class OfflineSyncManager: ObservableObject {
+class OfflineSyncManager: ObservableObject, @unchecked Sendable {
     static let shared = OfflineSyncManager()
     
     @Published var isSyncing = false
@@ -99,10 +99,9 @@ class OfflineSyncManager: ObservableObject {
     }
     
     private func getOfflineBookmarks() -> [ArticleURLEntity] {
-        let fetchRequest: NSFetchRequest<ArticleURLEntity> = ArticleURLEntity.fetchRequest()
-        
         do {
-            return try coreDataManager.context.fetch(fetchRequest)
+            let fetchRequest: NSFetchRequest<ArticleURLEntity> = ArticleURLEntity.fetchRequest()
+            return try coreDataManager.context.safeFetch(fetchRequest)
         } catch {
             print("Failed to fetch offline bookmarks: \(error)")
             return []
@@ -110,8 +109,16 @@ class OfflineSyncManager: ObservableObject {
     }
     
     private func deleteOfflineBookmark(_ entity: ArticleURLEntity) {
-        coreDataManager.context.delete(entity)
+        do {
-        coreDataManager.save()
+            try coreDataManager.context.safePerform { [weak self] in
+                guard let self = self else { return }
+                
+                self.coreDataManager.context.delete(entity)
+                self.coreDataManager.save()
+            }
+        } catch {
+            print("Failed to delete offline bookmark: \(error)")
+        }
     }
     
     // MARK: - Auto Sync on Server Connectivity Changes

readeck/Data/Repository/SettingsRepository.swift

@@ -42,6 +42,15 @@ class SettingsRepository: PSettingsRepository {
     private let userDefault = UserDefaults.standard
     private let keychainHelper = KeychainHelper.shared
     
+    var hasFinishedSetup: Bool {
+        get {
+            return userDefault.value(forKey: "hasFinishedSetup") as? Bool ?? false
+        }
+        set {
+            userDefault.set(newValue, forKey: "hasFinishedSetup")
+        }
+    }
+    
     func saveSettings(_ settings: Settings) async throws {
         // Save credentials to keychain
         if let endpoint = settings.endpoint, !endpoint.isEmpty {
@@ -206,15 +215,6 @@ class SettingsRepository: PSettingsRepository {
         }
     }
     
-    var hasFinishedSetup: Bool {
-        get {
-            return userDefault.value(forKey: "hasFinishedSetup") as? Bool ?? false
-        }
-        set {
-            userDefault.set(newValue, forKey: "hasFinishedSetup")
-        }
-    }
-    
     func saveCardLayoutStyle(_ cardLayoutStyle: CardLayoutStyle) async throws {
         let context = coreDataManager.context
         

readeck/UI/BookmarkDetail/BookmarkDetailView.swift

@@ -190,7 +190,7 @@ struct BookmarkDetailView: View {
                 let offset = geo.frame(in: .global).minY
                 ZStack(alignment: .top) {
                     CachedAsyncImage(url: URL(string: viewModel.bookmarkDetail.imageUrl))
-                        .scaledToFit()
+                        .aspectRatio(contentMode: .fill)
                         .frame(width: geometry.size.width, height: headerHeight + (offset > 0 ? offset : 0))
                         .clipped()
                         .offset(y: (offset > 0 ? -offset : 0))                        

readeck/UI/Bookmarks/BookmarksView.swift

@@ -88,7 +88,8 @@ struct BookmarksView: View {
     
     private var shouldShowCenteredState: Bool {
         let isEmpty = viewModel.bookmarks?.bookmarks.isEmpty == true
-        return isEmpty && (viewModel.isLoading || viewModel.errorMessage != nil)
+        let hasError = viewModel.errorMessage != nil
+        return (isEmpty && viewModel.isLoading) || hasError
     }
     
     // MARK: - View Components
@@ -134,16 +135,16 @@ struct BookmarksView: View {
     @ViewBuilder
     private func errorView(message: String) -> some View {
         VStack(spacing: 16) {
-            Image(systemName: "exclamationmark.triangle.fill")
+            Image(systemName: viewModel.isNetworkError ? "wifi.slash" : "exclamationmark.triangle.fill")
                 .font(.system(size: 48))
                 .foregroundColor(.orange)
             
             VStack(spacing: 8) {
-                Text("Unable to load bookmarks")
+                Text(viewModel.isNetworkError ? "No internet connection" : "Unable to load bookmarks")
                     .font(.headline)
                     .foregroundColor(.primary)
                 
-                Text(message)
+                Text(viewModel.isNetworkError ? "Please check your internet connection and try again" : message)
                     .font(.subheadline)
                     .foregroundColor(.secondary)
                     .multilineTextAlignment(.center)
@@ -151,7 +152,7 @@ struct BookmarksView: View {
             
             Button("Try Again") {
                 Task {
-                    await viewModel.loadBookmarks(state: state, type: type, tag: tag)
+                    await viewModel.retryLoading()
                 }
             }
             .buttonStyle(.borderedProminent)

readeck/UI/Bookmarks/BookmarksViewModel.swift

@@ -13,6 +13,7 @@ class BookmarksViewModel {
     var isLoading = false
     var isInitialLoading = true
     var errorMessage: String?
+    var isNetworkError = false
     var currentState: BookmarkState = .unread
     var currentType = [BookmarkType.article]
     var currentTag: String? = nil
@@ -123,8 +124,22 @@ class BookmarksViewModel {
             )
             bookmarks = newBookmarks
             hasMoreData = newBookmarks.currentPage != newBookmarks.totalPages // check if more data is available
+            isNetworkError = false
         } catch {
+            // Check if it's a network error
+            if let urlError = error as? URLError {
+                switch urlError.code {
+                case .notConnectedToInternet, .networkConnectionLost, .timedOut, .cannotConnectToHost, .cannotFindHost:
+                    isNetworkError = true
+                    errorMessage = "No internet connection"
+                default:
+                    isNetworkError = false
                     errorMessage = "Error loading bookmarks"
+                }
+            } else {
+                isNetworkError = false
+                errorMessage = "Error loading bookmarks"
+            }
             // Don't clear bookmarks on error - keep existing data visible
         }
         
@@ -151,8 +166,21 @@ class BookmarksViewModel {
             bookmarks?.bookmarks.append(contentsOf: newBookmarks.bookmarks)
             hasMoreData = newBookmarks.currentPage != newBookmarks.totalPages
         } catch {
+            // Check if it's a network error
+            if let urlError = error as? URLError {
+                switch urlError.code {
+                case .notConnectedToInternet, .networkConnectionLost, .timedOut, .cannotConnectToHost, .cannotFindHost:
+                    isNetworkError = true
+                    errorMessage = "No internet connection"
+                default:
+                    isNetworkError = false
                     errorMessage = "Error loading more bookmarks"
                 }
+            } else {
+                isNetworkError = false
+                errorMessage = "Error loading more bookmarks"
+            }
+        }
         
         isLoading = false
     }
@@ -162,6 +190,13 @@ class BookmarksViewModel {
         await loadBookmarks(state: currentState)
     }
     
+    @MainActor
+    func retryLoading() async {
+        errorMessage = nil
+        isNetworkError = false
+        await loadBookmarks(state: currentState, type: currentType, tag: currentTag)
+    }
+    
     @MainActor
     func toggleArchive(bookmark: Bookmark) async {
         do {
@@ -258,6 +293,10 @@ class BookmarksViewModel {
     private func executeDelete(bookmark: Bookmark) async {
         do {
             try await deleteBookmarkUseCase.execute(bookmarkId: bookmark.id)
+            // If delete succeeds, remove bookmark from the list
+            await MainActor.run {
+                bookmarks?.bookmarks.removeAll { $0.id == bookmark.id }
+            }
         } catch {
             // If delete fails, restore the bookmark
             await MainActor.run {