Merge pull request #375 from kingst/retry-coredata-loading

Retry coredata loading and move initialization to async

Model/CoreDataInitializationCoordinator.swift

@@ -0,0 +1,43 @@
+/// This actor provides us with logic to handle cases when a caller
+/// tries to initialize a coreDataStack that is already initialized.
+actor CoreDataInitializationCoordinator {
+    private var isInitialized = false
+    private var initializationTask: Task<Void, Error>?
+
+    /// Ensures that initialization only happens once and manages multiple concurrent initialization requests.
+    /// This actor provides synchronization for the CoreDataStack initialization process.
+    ///
+    /// - Parameters:
+    ///   - initialization: A closure that performs the actual initialization work.
+    /// - Throws: Any error that might occur during initialization.
+    /// - Returns: Void once initialization is complete.
+    func ensureInitialized(perform initialization: @escaping () async throws -> Void) async throws {
+        // If already initialized, return immediately
+        if isInitialized {
+            return
+        }
+
+        // If initialization is in progress, await the existing task
+        if let existingTask = initializationTask {
+            try await existingTask.value
+            return
+        }
+
+        // Start a new initialization task
+        let newTask = Task {
+            do {
+                try await initialization()
+                isInitialized = true
+            } catch {
+                // Clear task reference on failure
+                initializationTask = nil
+                throw error
+            }
+            // Clear task reference on success
+            initializationTask = nil
+        }
+
+        initializationTask = newTask
+        try await newTask.value
+    }
+}

Model/CoreDataStack.swift

@@ -11,6 +11,9 @@ class CoreDataStack: ObservableObject {
 
     let persistentContainer: NSPersistentContainer
 
+    private let maxRetries = 3
+    private let initializationCoordinator = CoreDataInitializationCoordinator()
+
     private init(inMemory: Bool = false) {
         self.inMemory = inMemory
 
@@ -41,29 +44,12 @@ class CoreDataStack: ObservableObject {
         description.shouldMigrateStoreAutomatically = true
         description.shouldInferMappingModelAutomatically = true
 
-        persistentContainer.loadPersistentStores { _, error in
-            if let error = error as NSError? {
-                fatalError("Unresolved Error \(DebuggingIdentifiers.failed) \(error), \(error.userInfo)")
-            }
-        }
-
         persistentContainer.viewContext.automaticallyMergesChangesFromParent = false
         persistentContainer.viewContext.name = "viewContext"
         /// - Tag: viewContextmergePolicy
         persistentContainer.viewContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
         persistentContainer.viewContext.undoManager = nil
         persistentContainer.viewContext.shouldDeleteInaccessibleFaults = true
-
-        // Observe Core Data remote change notifications on the queue where the changes were made
-        notificationToken = Foundation.NotificationCenter.default.addObserver(
-            forName: .NSPersistentStoreRemoteChange,
-            object: nil,
-            queue: nil
-        ) { _ in
-            Task {
-                await self.fetchPersistentHistory()
-            }
-        }
     }
 
     deinit {
@@ -84,19 +70,18 @@ class CoreDataStack: ObservableObject {
     }
 
     // Factory method for tests
-    static func createForTests() -> CoreDataStack {
-        CoreDataStack(inMemory: true)
+    static func createForTests() async throws -> CoreDataStack {
+        let stack = CoreDataStack(inMemory: true)
+        try await stack.initializeStack()
+        return stack
     }
 
     // Used for Canvas Preview
-    static var preview: CoreDataStack = {
+    static func preview() async throws -> CoreDataStack {
         let stack = CoreDataStack(inMemory: true)
-        let context = stack.persistentContainer.viewContext
-
-        let pumpHistory = PumpEventStored.makePreviewEvents(count: 10, provider: stack)
-
+        try await stack.initializeStack()
         return stack
-    }()
+    }
 
     // Shared managed object model
     static var managedObjectModel: NSManagedObjectModel = {
@@ -183,13 +168,96 @@ class CoreDataStack: ObservableObject {
         }
     }
 
-    func initializeStack() throws {
-        // Force initialization of persistent container
-        let container = persistentContainer
+    private func setupPersistentStoreChangeNotifications() {
+        // Observe Core Data remote change notifications on the queue where the changes were made
+        notificationToken = Foundation.NotificationCenter.default.addObserver(
+            forName: .NSPersistentStoreRemoteChange,
+            object: nil,
+            queue: nil
+        ) { _ in
+            Task {
+                await self.fetchPersistentHistory()
+            }
+        }
+
+        debug(.coreData, "Set up persistent store change notifications")
+    }
+
+    /// Loads the persistent stores asynchronously.
+    ///
+    /// Converts the synchronous NSPersistentContainer loading process into an async/await compatible
+    /// function using a continuation.
+    ///
+    /// - Throws: Any errors encountered during the loading of persistent stores.
+    /// - Returns: Void once stores are loaded successfully
+    private func loadPersistentStores() async throws {
+        try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, Error>) in
+            persistentContainer.loadPersistentStores { storeDescription, error in
+                if let error = error {
+                    warning(.coreData, "Failed to load persistent stores: \(error.localizedDescription)")
+                    continuation.resume(throwing: error)
+                } else {
+                    debug(.coreData, "Successfully loaded persistent store: \(storeDescription.url?.absoluteString ?? "unknown")")
+                    continuation.resume(returning: ())
+                }
+            }
+        }
+    }
+
+    /// Public entry point for initializing the CoreData stack.
+    ///
+    /// Uses the initialization coordinator to ensure initialization happens only once,
+    /// even with concurrent calls. Subsequent calls will wait for the original initialization
+    /// to complete.
+    ///
+    /// - Throws: Any errors that occur during initialization.
+    /// - Returns: Void once initialization is complete.
+    func initializeStack() async throws {
+        try await initializationCoordinator.ensureInitialized {
+            try await self.initializeStack(retryCount: 0)
+        }
+    }
+
+    /// Private implementation of the initialization process with retry capability.
+    ///
+    /// Handles the actual initialization work including store loading, verification,
+    /// notification setup, and error handling with retry logic.
+    ///
+    /// - Parameter retryCount: The current retry attempt number, starting at 0.
+    /// - Throws: CoreDataError or any other error if initialization fails after all retries.
+    /// - Returns: Void when initialization completes successfully.
+    private func initializeStack(retryCount: Int) async throws {
+        do {
+            // Load stores asynchronously
+            try await loadPersistentStores()
+
+            // Verify the store is loaded
+            guard persistentContainer.persistentStoreCoordinator.persistentStores.isEmpty == false else {
+                let error = CoreDataError.storeNotInitializedError(function: #function, file: #file)
+                throw error
+            }
+
+            setupPersistentStoreChangeNotifications()
 
-        // Verify the store is loaded
-        guard container.persistentStoreCoordinator.persistentStores.isEmpty == false else {
-            throw CoreDataError.storeNotInitializedError(function: #function, file: #file)
+            debug(.coreData, "Core Data stack initialized successfully")
+
+        } catch {
+            debug(.coreData, "Failed to initialize Core Data stack: \(error.localizedDescription)")
+
+            // If we still have retries left, try again after a delay
+            if retryCount < maxRetries {
+                debug(.coreData, "Retrying initialization (\(retryCount + 1)/\(maxRetries))")
+
+                // Wait before retrying
+                try await Task.sleep(for: .seconds(1))
+
+                // Retry the initialization
+                try await initializeStack(retryCount: retryCount + 1)
+            } else {
+                // We've exhausted our retries
+                debug(.coreData, "Core Data initialization failed after \(maxRetries) attempts")
+                throw error
+            }
         }
     }
 }

Trio.xcodeproj/project.pbxproj

@@ -202,14 +202,16 @@
 		38FEF3FC2737E53800574A46 /* MainStateModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 38FEF3FB2737E53800574A46 /* MainStateModel.swift */; };
 		38FEF3FE2738083E00574A46 /* CGMSettingsProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 38FEF3FD2738083E00574A46 /* CGMSettingsProvider.swift */; };
 		38FEF413273B317A00574A46 /* HKUnit.swift in Sources */ = {isa = PBXBuildFile; fileRef = 38FEF412273B317A00574A46 /* HKUnit.swift */; };
+		3B2F77862D7E52ED005ED9FA /* TDD.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3B2F77852D7E52ED005ED9FA /* TDD.swift */; };
+		3B2F77882D7E5387005ED9FA /* CurrentTDDSetup.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3B2F77872D7E5387005ED9FA /* CurrentTDDSetup.swift */; };
+		3BAD36B22D7CDC1A00CC298D /* MainLoadingView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3BAD36B12D7CDC1400CC298D /* MainLoadingView.swift */; };
+		3BAD36CC2D7D420E00CC298D /* CoreDataInitializationCoordinator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3BAD36CB2D7D420500CC298D /* CoreDataInitializationCoordinator.swift */; };
 		45252C95D220E796FDB3B022 /* ConfigEditorDataFlow.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3F8A87AA037BD079BA3528BA /* ConfigEditorDataFlow.swift */; };
 		45717281F743594AA9D87191 /* ConfigEditorRootView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 920DDB21E5D0EB813197500D /* ConfigEditorRootView.swift */; };
 		491D6FBD2D56741C00C49F67 /* TempTargetStored+CoreDataProperties.swift in Sources */ = {isa = PBXBuildFile; fileRef = 491D6FBC2D56741C00C49F67 /* TempTargetStored+CoreDataProperties.swift */; };
 		491D6FBE2D56741C00C49F67 /* TempTargetRunStored+CoreDataClass.swift in Sources */ = {isa = PBXBuildFile; fileRef = 491D6FB92D56741C00C49F67 /* TempTargetRunStored+CoreDataClass.swift */; };
 		491D6FBF2D56741C00C49F67 /* TempTargetRunStored+CoreDataProperties.swift in Sources */ = {isa = PBXBuildFile; fileRef = 491D6FBA2D56741C00C49F67 /* TempTargetRunStored+CoreDataProperties.swift */; };
 		491D6FC02D56741C00C49F67 /* TempTargetStored+CoreDataClass.swift in Sources */ = {isa = PBXBuildFile; fileRef = 491D6FBB2D56741C00C49F67 /* TempTargetStored+CoreDataClass.swift */; };
-		49249B1C2D46E45E000F4866 /* CurrentTDDSetup.swift in Sources */ = {isa = PBXBuildFile; fileRef = 49249B1B2D46E45E000F4866 /* CurrentTDDSetup.swift */; };
-		49249B382D46E76A000F4866 /* TDD.swift in Sources */ = {isa = PBXBuildFile; fileRef = 49249B372D46E76A000F4866 /* TDD.swift */; };
 		49B9B57F2D5768D2009C6B59 /* AdjustmentStored+Helper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 49B9B57E2D5768D2009C6B59 /* AdjustmentStored+Helper.swift */; };
 		5075C1608E6249A51495C422 /* TargetsEditorProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3BDEA2DC60EDE0A3CA54DC73 /* TargetsEditorProvider.swift */; };
 		53F2382465BF74DB1A967C8B /* PumpConfigProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = A8630D58BDAD6D9C650B9B39 /* PumpConfigProvider.swift */; };
@@ -921,6 +923,10 @@
 		38FEF3FB2737E53800574A46 /* MainStateModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MainStateModel.swift; sourceTree = "<group>"; };
 		38FEF3FD2738083E00574A46 /* CGMSettingsProvider.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CGMSettingsProvider.swift; sourceTree = "<group>"; };
 		38FEF412273B317A00574A46 /* HKUnit.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = HKUnit.swift; sourceTree = "<group>"; };
+		3B2F77852D7E52ED005ED9FA /* TDD.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TDD.swift; sourceTree = "<group>"; };
+		3B2F77872D7E5387005ED9FA /* CurrentTDDSetup.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CurrentTDDSetup.swift; sourceTree = "<group>"; };
+		3BAD36B12D7CDC1400CC298D /* MainLoadingView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MainLoadingView.swift; sourceTree = "<group>"; };
+		3BAD36CB2D7D420500CC298D /* CoreDataInitializationCoordinator.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CoreDataInitializationCoordinator.swift; sourceTree = "<group>"; };
 		3BDEA2DC60EDE0A3CA54DC73 /* TargetsEditorProvider.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = TargetsEditorProvider.swift; sourceTree = "<group>"; };
 		3BF768BD6264FF7D71D66767 /* NightscoutConfigProvider.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = NightscoutConfigProvider.swift; sourceTree = "<group>"; };
 		3F60E97100041040446F44E7 /* PumpConfigStateModel.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = PumpConfigStateModel.swift; sourceTree = "<group>"; };
@@ -931,8 +937,6 @@
 		491D6FBA2D56741C00C49F67 /* TempTargetRunStored+CoreDataProperties.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "TempTargetRunStored+CoreDataProperties.swift"; sourceTree = "<group>"; };
 		491D6FBB2D56741C00C49F67 /* TempTargetStored+CoreDataClass.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "TempTargetStored+CoreDataClass.swift"; sourceTree = "<group>"; };
 		491D6FBC2D56741C00C49F67 /* TempTargetStored+CoreDataProperties.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "TempTargetStored+CoreDataProperties.swift"; sourceTree = "<group>"; };
-		49249B1B2D46E45E000F4866 /* CurrentTDDSetup.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CurrentTDDSetup.swift; sourceTree = "<group>"; };
-		49249B372D46E76A000F4866 /* TDD.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TDD.swift; sourceTree = "<group>"; };
 		49B9B57E2D5768D2009C6B59 /* AdjustmentStored+Helper.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "AdjustmentStored+Helper.swift"; sourceTree = "<group>"; };
 		4DD795BA46B193644D48138C /* TargetsEditorRootView.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = TargetsEditorRootView.swift; sourceTree = "<group>"; };
 		505E09DC17A0C3D0AF4B66FE /* ISFEditorStateModel.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = ISFEditorStateModel.swift; sourceTree = "<group>"; };
@@ -1739,6 +1743,7 @@
 		3811DE1F25C9D48300A708ED /* View */ = {
 			isa = PBXGroup;
 			children = (
+				3BAD36B12D7CDC1400CC298D /* MainLoadingView.swift */,
 				3811DE2025C9D48300A708ED /* MainRootView.swift */,
 			);
 			path = View;
@@ -2092,7 +2097,7 @@
 		388E5A5925B6F0250019842D /* Models */ = {
 			isa = PBXGroup;
 			children = (
-				49249B372D46E76A000F4866 /* TDD.swift */,
+				3B2F77852D7E52ED005ED9FA /* TDD.swift */,
 				DD4FFF322D458EE600B6CFF9 /* GarminWatchState.swift */,
 				DD3078692D42F94000DE0490 /* GarminDevice.swift */,
 				DD3078672D42F5CE00DE0490 /* WatchGlucoseObject.swift */,
@@ -2415,13 +2420,13 @@
 		58645B972CA2D16A008AFCE7 /* HomeStateModel+Setup */ = {
 			isa = PBXGroup;
 			children = (
+				3B2F77872D7E5387005ED9FA /* CurrentTDDSetup.swift */,
 				BD4E1A7B2D3686D400D21626 /* StartEndMarkerSetup.swift */,
 				BD4E1A792D3681AD00D21626 /* GlucoseTargetSetup.swift */,
 				BDA6CC872CAF219800F942F9 /* TempTargetSetup.swift */,
 				58645B982CA2D1A4008AFCE7 /* GlucoseSetup.swift */,
 				58645B9A2CA2D24F008AFCE7 /* CarbSetup.swift */,
 				58645B9C2CA2D275008AFCE7 /* DeterminationSetup.swift */,
-				49249B1B2D46E45E000F4866 /* CurrentTDDSetup.swift */,
 				58645B9E2CA2D2BE008AFCE7 /* PumpHistorySetup.swift */,
 				58645BA02CA2D2F8008AFCE7 /* OverrideSetup.swift */,
 				58645BA22CA2D325008AFCE7 /* BatterySetup.swift */,
@@ -2434,6 +2439,7 @@
 		587A54C82BCDCE0F009D38E2 /* Model */ = {
 			isa = PBXGroup;
 			children = (
+				3BAD36CB2D7D420500CC298D /* CoreDataInitializationCoordinator.swift */,
 				BDF34F8F2C10CF8C00D51995 /* CoreDataStack.swift */,
 				BD4064D02C4ED26900582F43 /* CoreDataObserver.swift */,
 				DDD1631D2C4C6F6900CD525A /* TrioCoreDataPersistentContainer.xcdatamodeld */,
@@ -3745,6 +3751,7 @@
 				3811DEB125C9D88300A708ED /* Keychain.swift in Sources */,
 				DD17453E2C55BFB600211FAC /* AlgorithmAdvancedSettingsStateModel.swift in Sources */,
 				CE95BF572BA5F5FE00DC3DE3 /* PluginManager.swift in Sources */,
+				3BAD36B22D7CDC1A00CC298D /* MainLoadingView.swift in Sources */,
 				382C133725F13A1E00715CE1 /* InsulinSensitivities.swift in Sources */,
 				19D466A529AA2BD4004D5F33 /* MealSettingsProvider.swift in Sources */,
 				DD5DC9F72CF3DA9300AB8703 /* TargetPicker.swift in Sources */,
@@ -3753,6 +3760,7 @@
 				3811DE4125C9D4A100A708ED /* SettingsRootView.swift in Sources */,
 				38192E04261B82FA0094D973 /* ReachabilityManager.swift in Sources */,
 				38E44539274E411700EC9A94 /* Disk+UIImage.swift in Sources */,
+				3BAD36CC2D7D420E00CC298D /* CoreDataInitializationCoordinator.swift in Sources */,
 				388E595C25AD948C0019842D /* TrioApp.swift in Sources */,
 				38FEF3FC2737E53800574A46 /* MainStateModel.swift in Sources */,
 				DD1745352C55AE7E00211FAC /* TargetBehavoirRootView.swift in Sources */,
@@ -4020,6 +4028,7 @@
 				DDF847DF2C5C28780049BB3B /* LiveActivitySettingsProvider.swift in Sources */,
 				DDB37CC52D05048F00D99BF4 /* ContactImageStorage.swift in Sources */,
 				BD54A95B2D28087C00F9C1EE /* OverridePresetWatch.swift in Sources */,
+				3B2F77882D7E5387005ED9FA /* CurrentTDDSetup.swift in Sources */,
 				DBA5254DBB2586C98F61220C /* ISFEditorProvider.swift in Sources */,
 				BDF34EBE2C0A31D100D51995 /* CustomNotification.swift in Sources */,
 				BDC2EA472C3045AD00E5BBD0 /* Override.swift in Sources */,
@@ -4045,7 +4054,6 @@
 				38E44538274E411700EC9A94 /* Disk+[Data].swift in Sources */,
 				98641AF4F92123DA668AB931 /* CarbRatioEditorRootView.swift in Sources */,
 				BDF34F902C10CF8C00D51995 /* CoreDataStack.swift in Sources */,
-				49249B1C2D46E45E000F4866 /* CurrentTDDSetup.swift in Sources */,
 				CEE9A65C2BBB41C800EB5194 /* CalibrationService.swift in Sources */,
 				110AEDED2C51A0AE00615CC9 /* ShortcutsConfigProvider.swift in Sources */,
 				38E4453D274E411700EC9A94 /* Disk+Errors.swift in Sources */,
@@ -4063,7 +4071,6 @@
 				9702FF92A09C53942F20D7EA /* TargetsEditorRootView.swift in Sources */,
 				1967DFBE29D052C200759F30 /* Icons.swift in Sources */,
 				DDD163182C4C694000CD525A /* AdjustmentsRootView.swift in Sources */,
-				49249B382D46E76A000F4866 /* TDD.swift in Sources */,
 				389ECE052601144100D86C4F /* ConcurrentMap.swift in Sources */,
 				110AEDEC2C51A0AE00615CC9 /* ShortcutsConfigDataFlow.swift in Sources */,
 				CE7CA3562A064973004BE681 /* StateIntentRequest.swift in Sources */,
@@ -4123,6 +4130,7 @@
 				38E44534274E411700EC9A94 /* Disk+InternalHelpers.swift in Sources */,
 				38A00B2325FC2B55006BC0B0 /* LRUCache.swift in Sources */,
 				DDD163122C4C689900CD525A /* AdjustmentsStateModel.swift in Sources */,
+				3B2F77862D7E52ED005ED9FA /* TDD.swift in Sources */,
 				DD1745132C54169400211FAC /* DevicesView.swift in Sources */,
 				7F7B756BE8543965D9FDF1A2 /* DataTableDataFlow.swift in Sources */,
 				1D845DF2E3324130E1D95E67 /* DataTableProvider.swift in Sources */,

Trio/Resources/Assets.xcassets/app_icon_images/trioCircledNoBackground.imageset/Contents.json

@@ -0,0 +1,12 @@
+{
+  "images" : [
+    {
+      "filename" : "ComplicationIcon.png",
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

Trio/Resources/Assets.xcassets/app_icons/trioCircledNoBackground.imageset/Contents.json

@@ -0,0 +1,12 @@
+{
+  "images" : [
+    {
+      "filename" : "ComplicationIcon.png",
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

Trio/Sources/Application/AppDelegate.swift

@@ -4,11 +4,11 @@ import UserNotifications
 
 class AppDelegate: NSObject, UIApplicationDelegate, ObservableObject, UNUserNotificationCenterDelegate {
     func application(
-        _ application: UIApplication,
+        _: UIApplication,
         didFinishLaunchingWithOptions _: [UIApplication.LaunchOptionsKey: Any]?
     ) -> Bool {
-        application.registerForRemoteNotifications()
-        return true
+        // application.registerForRemoteNotifications()
+        true
     }
 
     func application(

Trio/Sources/Application/TrioApp.swift

@@ -5,6 +5,11 @@ import Foundation
 import SwiftUI
 import Swinject
 
+extension Notification.Name {
+    static let initializationCompleted = Notification.Name("initializationCompleted")
+    static let initializationError = Notification.Name("initializationError")
+}
+
 @main struct TrioApp: App {
     @Environment(\.scenePhase) var scenePhase
 
@@ -13,9 +18,21 @@ import Swinject
     // Read the color scheme preference from UserDefaults; defaults to system default setting
     @AppStorage("colorSchemePreference") private var colorSchemePreference: ColorSchemeOption = .systemDefault
 
-    let coreDataStack: CoreDataStack
+    let coreDataStack = CoreDataStack.shared
+    class InitState {
+        var complete = false
+        var error = false
+    }
+
+    // We use both InitState and @State variables to track coreDataStack
+    // initialization. We need both to handle the cases when the coreDataStack
+    // finishes before the UI and when it finishes after. SwiftUI doesn't have
+    // clean mechanisms for handling background thread updates, thus this solution.
+    let initState = InitState()
 
     @State private var appState = AppState()
+    @State private var showLoadingView = true
+    @State private var showLoadingError = false
 
     // Dependencies Assembler
     // contain all dependencies Assemblies
@@ -72,36 +89,83 @@ import Swinject
             "Trio Started: v\(Bundle.main.releaseVersionNumber ?? "")(\(Bundle.main.buildVersionNumber ?? "")) [buildDate: \(String(describing: BuildDetails.default.buildDate()))] [buildExpires: \(String(describing: BuildDetails.default.calculateExpirationDate()))] [submodules: \(submodulesInfo)]"
         )
 
-        // Setup up the Core Data Stack
-        coreDataStack = CoreDataStack.shared
+        // Fix bug in iOS 18 related to the translucent tab bar
+        configureTabBarAppearance()
 
-        // Explicitly initialize Core Data Stack
-        do {
-            try coreDataStack.initializeStack()
+        deferredInitialization()
+    }
 
-            // Only load services after successful Core Data initialization
-            loadServices()
+    /// Handles the deferred initialization of core components.
+    ///
+    /// Performs CoreDataStack initialization asynchronously and notifies the UI
+    /// of completion or errors via notifications.
+    private func deferredInitialization() {
+        Task {
+            do {
+                try await coreDataStack.initializeStack()
 
-            // Fix bug in iOS 18 related to the translucent tab bar
-            configureTabBarAppearance()
+                await MainActor.run {
+                    // Only load services after successful Core Data initialization
+                    loadServices()
 
-            // Clear the persistentHistory and the NSManagedObjects that are older than 90 days every time the app starts
-            cleanupOldData()
-        } catch {
-            debug(.coreData, "\(DebuggingIdentifiers.failed) Failed to initialize Core Data Stack: \(error.localizedDescription)")
+                    // Clear the persistentHistory and the NSManagedObjects that are older than 90 days every time the app starts
+                    cleanupOldData()
 
-            fatalError("Core Data Stack initialization failed")
+                    self.initState.complete = true
+                    Foundation.NotificationCenter.default.post(name: .initializationCompleted, object: nil)
+                    UIApplication.shared.registerForRemoteNotifications()
+                }
+            } catch {
+                debug(
+                    .coreData,
+                    "\(DebuggingIdentifiers.failed) Failed to initialize Core Data Stack: \(error.localizedDescription)"
+                )
+
+                await MainActor.run {
+                    self.initState.error = true
+                    Foundation.NotificationCenter.default.post(name: .initializationError, object: nil)
+                }
+            }
         }
     }
 
+    /// Attempts to initialize the CoreDataStack again after a previous failure.
+    ///
+    /// Resets error states and triggers the initialization process from the beginning. Called in response
+    /// to a UI "retry" button press from the Main.LoadingView
+    private func retryCoreDataInitialization() {
+        showLoadingError = false
+        initState.error = false
+        deferredInitialization()
+    }
+
     var body: some Scene {
         WindowGroup {
-            Main.RootView(resolver: resolver)
-                .preferredColorScheme(colorScheme(for: colorSchemePreference) ?? nil)
-                .environment(\.managedObjectContext, coreDataStack.persistentContainer.viewContext)
-                .environment(appState)
-                .environmentObject(Icons())
-                .onOpenURL(perform: handleURL)
+            if self.showLoadingView {
+                Main.LoadingView(showError: $showLoadingError, retry: retryCoreDataInitialization)
+                    .onAppear {
+                        if self.initState.complete {
+                            self.showLoadingView = false
+                        }
+                        if self.initState.error {
+                            self.showLoadingError = true
+                        }
+                    }
+                    .onReceive(Foundation.NotificationCenter.default.publisher(for: .initializationCompleted)) { _ in
+                        self.showLoadingView = false
+                    }
+                    .onReceive(Foundation.NotificationCenter.default.publisher(for: .initializationError)) { _ in
+                        self.showLoadingError = true
+                    }
+
+            } else {
+                Main.RootView(resolver: resolver)
+                    .preferredColorScheme(colorScheme(for: colorSchemePreference) ?? nil)
+                    .environment(\.managedObjectContext, coreDataStack.persistentContainer.viewContext)
+                    .environment(appState)
+                    .environmentObject(Icons())
+                    .onOpenURL(perform: handleURL)
+            }
         }
         .onChange(of: scenePhase) { _, newScenePhase in
             debug(.default, "APPLICATION PHASE: \(newScenePhase)")
@@ -117,9 +181,9 @@ import Swinject
                 {
                     AppVersionChecker.shared.checkAndNotifyVersionStatus(in: rootVC)
                 }
-
-                // Check if we need to perform a database cleaning
-                performCleanupIfNecessary()
+                if initState.complete {
+                    performCleanupIfNecessary()
+                }
             }
         }
     }

Trio/Sources/Localizations/Main/Localizable.xcstrings

@@ -88601,6 +88601,9 @@
         }
       }
     },
+    "Getting everything ready for you..." : {
+
+    },
     "Give Apple Health Write Permissions" : {
       "localizations" : {
         "bg" : {
@@ -129260,6 +129263,9 @@
         }
       }
     },
+    "Oops, there was an issue!" : {
+
+    },
     "Open %@" : {
       "localizations" : {
         "bg" : {
@@ -142722,6 +142728,9 @@
         }
       }
     },
+    "Retry" : {
+
+    },
     "Return to Normal" : {
       "extractionState" : "manual",
       "localizations" : {
@@ -157170,6 +157179,9 @@
         }
       }
     },
+    "Something went wrong while loading your data. Please try again in a few moments." : {
+
+    },
     "Source of the glucose reading will be added to the notification." : {
       "localizations" : {
         "bg" : {
@@ -183129,6 +183141,9 @@
     "Trio Up-Time Chart" : {
 
     },
+    "Trio v%@" : {
+
+    },
     "Trio v%@ (%@)" : {
       "localizations" : {
         "bg" : {

Trio/Sources/Models/Icons.swift

@@ -7,6 +7,7 @@ enum Icon_: String, CaseIterable, Identifiable {
     case trioWhiteShadow
     case trioColorBG
     case trioWhite
+    case trioCircledNoBackground
     case trio3D
     case wilford = "diabeetus"
     case catWithPod

Trio/Sources/Modules/Home/View/Chart/ChartElements/GlucoseChartView.swift

@@ -78,23 +78,48 @@ struct GlucoseChartView: ChartContent {
 }
 
 #Preview {
-    let previewStack = CoreDataStack.preview
-    return NavigationView {
-        VStack {
-            Chart {
-                GlucoseChartView(
-                    glucoseData: GlucoseStored.makePreviewGlucose(count: 24, provider: previewStack),
-                    units: .mgdL,
-                    highGlucose: 180,
-                    lowGlucose: 70,
-                    currentGlucoseTarget: 100,
-                    isSmoothingEnabled: false,
-                    glucoseColorScheme: .dynamicColor
-                )
+    struct PreviewWrapper: View {
+        @State private var previewStack: CoreDataStack? = nil
+        @State private var glucoseData: [GlucoseStored] = []
+        @State private var isLoading = true
+
+        var body: some View {
+            NavigationView {
+                Group {
+                    if isLoading {
+                        ProgressView("Loading data...")
+                    } else {
+                        VStack {
+                            Chart {
+                                GlucoseChartView(
+                                    glucoseData: glucoseData,
+                                    units: .mgdL,
+                                    highGlucose: 180,
+                                    lowGlucose: 70,
+                                    currentGlucoseTarget: 100,
+                                    isSmoothingEnabled: false,
+                                    glucoseColorScheme: .dynamicColor
+                                )
+                            }
+                            .frame(height: 200)
+                            .padding()
+                        }
+                    }
+                }
+                .navigationTitle("Glucose Chart")
+                .task {
+                    // Use the preview stack that's initialized asynchronously in CoreDataStack
+                    previewStack = try? await CoreDataStack.preview()
+
+                    // Now you can safely create preview data
+                    if let stack = previewStack {
+                        glucoseData = GlucoseStored.makePreviewGlucose(count: 24, provider: stack)
+                        isLoading = false
+                    }
+                }
             }
-            .frame(height: 200)
-            .padding()
         }
-        .navigationTitle("Glucose Chart")
     }
+
+    return PreviewWrapper()
 }

Trio/Sources/Modules/Main/View/MainLoadingView.swift

@@ -0,0 +1,91 @@
+import SwiftUI
+
+extension Main {
+    struct LoadingView: View {
+        @Binding var showError: Bool
+        let retry: () -> Void
+
+        private let versionNumber = Bundle.main.releaseVersionNumber ?? String(localized: "Unknown")
+
+        var body: some View {
+            ZStack {
+                LinearGradient(
+                    gradient: Gradient(colors: [Color.bgDarkBlue, Color.bgDarkerDarkBlue]),
+                    startPoint: .top,
+                    endPoint: .bottom
+                )
+                .ignoresSafeArea()
+
+                VStack {
+                    Spacer().frame(maxHeight: 92)
+
+                    Image(.trioCircledNoBackground)
+                        .resizable()
+                        .scaledToFit()
+                        .frame(width: 92, height: 92)
+                        .shadow(color: Color.white.opacity(0.1), radius: 5, x: 0, y: 0)
+
+                    Text("Trio v\(versionNumber)")
+                        .fontWeight(.heavy)
+                        .foregroundStyle(Color(red: 148 / 255, green: 102 / 255, blue: 234 / 255))
+                        .padding(.vertical)
+
+                    if showError {
+                        Spacer().frame(maxHeight: 60)
+
+                        VStack(alignment: .leading, spacing: 12) {
+                            Text("Oops, there was an issue!").font(.title3).bold()
+
+                            Text("Something went wrong while loading your data. Please try again in a few moments.")
+                                .foregroundStyle(.white)
+                        }
+                        .padding(.horizontal, 24)
+                        .foregroundStyle(.white)
+
+                        Spacer()
+
+                        RetryButton(action: retry).padding(.bottom, 60)
+                    } else {
+                        Spacer().frame(maxHeight: 100)
+
+                        CustomProgressView(text: String(localized: "Getting everything ready for you...")).foregroundStyle(.white)
+
+                        Spacer()
+                    }
+                }
+            }
+        }
+    }
+
+    struct RetryButton: View {
+        var action: () -> Void
+
+        var body: some View {
+            Button(action: action) {
+                HStack(spacing: 8) {
+                    Image(systemName: "arrow.clockwise")
+                    Text("Retry")
+                }
+                .frame(width: UIScreen.main.bounds.width - 60, height: 50)
+                .font(.title3).bold()
+                .background(
+                    Capsule()
+                        .fill(Color.tabBar)
+                )
+                .foregroundColor(.white)
+                .shadow(color: Color.black.opacity(0.1), radius: 5, x: 0, y: 2)
+            }
+        }
+    }
+}
+
+struct LoadingView_Previews: PreviewProvider {
+    static var previews: some View {
+        Group {
+            Main.LoadingView(showError: .constant(false), retry: {})
+                .previewDisplayName("Loading")
+            Main.LoadingView(showError: .constant(true), retry: {})
+                .previewDisplayName("Error")
+        }
+    }
+}

TrioTests/CoreDataTests/CarbsStorageTests.swift

@@ -8,11 +8,12 @@ import Testing
 @Suite("CarbsStorage Tests", .serialized) struct CarbsStorageTests: Injectable {
     @Injected() var storage: CarbsStorage!
     let resolver: Resolver
-    let coreDataStack = CoreDataStack.createForTests()
-    let testContext: NSManagedObjectContext
+    var coreDataStack: CoreDataStack!
+    var testContext: NSManagedObjectContext!
 
-    init() {
+    init() async throws {
         // Create test context
+        coreDataStack = try await CoreDataStack.createForTests()
         testContext = coreDataStack.newTaskContext()
 
         // Create assembler with test assembly
@@ -55,7 +56,7 @@ import Testing
 
         // When
         try await storage.storeCarbs(testEntries, areFetchedFromRemote: false)
-        let recentEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let recentEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: CarbEntryStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "TRUEPREDICATE"),
@@ -95,7 +96,7 @@ import Testing
         try await storage.storeCarbs([testEntry], areFetchedFromRemote: false)
 
         // Get the stored entry's ObjectID
-        let storedEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let storedEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: CarbEntryStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "carbs == 30"),
@@ -111,7 +112,7 @@ import Testing
         await storage.deleteCarbsEntryStored(objectID)
 
         // Then - verify deletion
-        let remainingEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let remainingEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: CarbEntryStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "carbs == 30"),
@@ -166,7 +167,7 @@ import Testing
         try await storage.storeCarbs([testEntry], areFetchedFromRemote: false)
 
         // First verify all stored entries
-        let allStoredEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let allStoredEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: CarbEntryStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "fpuID == %@", fpuID),

TrioTests/CoreDataTests/DeterminationStorageTests.swift

@@ -8,12 +8,13 @@ import Testing
 @Suite("Determination Storage Tests", .serialized) struct DeterminationStorageTests: Injectable {
     @Injected() var storage: DeterminationStorage!
     let resolver: Resolver
-    let coreDataStack = CoreDataStack.createForTests()
-    let testContext: NSManagedObjectContext
+    var coreDataStack: CoreDataStack!
+    var testContext: NSManagedObjectContext!
 
-    init() {
+    init() async throws {
         // Create test context
         // As we are only using this single test context to initialize our in-memory DeterminationStorage we need to perform the Unit Tests serialized
+        coreDataStack = try await CoreDataStack.createForTests()
         testContext = coreDataStack.newTaskContext()
 
         // Create assembler with test assembly

TrioTests/CoreDataTests/GlucoseStorageTests.swift

@@ -8,12 +8,13 @@ import Testing
 @Suite("GlucoseStorage Tests", .serialized) struct GlucoseStorageTests: Injectable {
     @Injected() var storage: GlucoseStorage!
     let resolver: Resolver
-    let coreDataStack = CoreDataStack.createForTests()
-    let testContext: NSManagedObjectContext
+    var coreDataStack: CoreDataStack!
+    var testContext: NSManagedObjectContext!
 
-    init() {
+    init() async throws {
         // Create test context
         // As we are only using this single test context to initialize our in-memory DeterminationStorage we need to perform the Unit Tests serialized
+        coreDataStack = try await CoreDataStack.createForTests()
         testContext = coreDataStack.newTaskContext()
 
         // Create assembler with test assembly
@@ -49,7 +50,7 @@ import Testing
         try await storage.storeGlucose(testGlucose)
 
         // Then verify stored entries
-        let storedEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let storedEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: GlucoseStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "glucose == 126"),
@@ -71,7 +72,7 @@ import Testing
         try await storage.storeGlucose(testGlucose)
 
         // Get the stored entry's ObjectID
-        let storedEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let storedEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: GlucoseStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "glucose == 140"),
@@ -89,7 +90,7 @@ import Testing
         await storage.deleteGlucose(objectID)
 
         // Then verify deletion
-        let remainingEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let remainingEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: GlucoseStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "glucose == 140"),
@@ -144,7 +145,7 @@ import Testing
 
         // When - Test low glucose
         try await storage.storeGlucose(lowGlucose)
-        var storedEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        var storedEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: GlucoseStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "glucose == 55"),
@@ -158,7 +159,7 @@ import Testing
 
         // When - Test high glucose
         try await storage.storeGlucose(highGlucose)
-        storedEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        storedEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: GlucoseStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "glucose == 271"),
@@ -172,7 +173,7 @@ import Testing
 
         // When - Test normal glucose
         try await storage.storeGlucose(normalGlucose)
-        storedEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        storedEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: GlucoseStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "glucose == 100"),

TrioTests/CoreDataTests/OverrideStorageTests.swift

@@ -8,12 +8,13 @@ import Testing
 @Suite("Override Storage Tests", .serialized) struct OverrideStorageTests: Injectable {
     @Injected() var storage: OverrideStorage!
     let resolver: Resolver
-    let coreDataStack = CoreDataStack.createForTests()
-    let testContext: NSManagedObjectContext
+    var coreDataStack: CoreDataStack!
+    var testContext: NSManagedObjectContext!
 
-    init() {
+    init() async throws {
         // Create test context
         // As we are only using this single test context to initialize our in-memory DeterminationStorage we need to perform the Unit Tests serialized
+        coreDataStack = try await CoreDataStack.createForTests()
         testContext = coreDataStack.newTaskContext()
 
         // Create assembler with test assembly
@@ -68,7 +69,7 @@ import Testing
         try await storage.storeOverride(override: testOverride)
 
         // Then verify stored entries
-        let storedEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let storedEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: OverrideStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "name == %@", "Test Override"),
@@ -158,7 +159,7 @@ import Testing
         try await storage.storeOverride(override: testPreset)
 
         // Get the stored preset's ObjectID
-        let storedEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let storedEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: OverrideStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "name == %@", "Delete Test"),
@@ -174,7 +175,7 @@ import Testing
         await storage.deleteOverridePreset(objectID)
 
         // Then verify deletion
-        let remainingEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let remainingEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: OverrideStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "name == %@", "Delete Test"),

TrioTests/CoreDataTests/PumpHistoryStorageTests.swift

@@ -9,12 +9,13 @@ import Testing
 @Suite("PumpHistoryStorage Tests", .serialized) struct PumpHistoryStorageTests: Injectable {
     @Injected() var storage: PumpHistoryStorage!
     let resolver: Resolver
-    let coreDataStack = CoreDataStack.createForTests()
-    let testContext: NSManagedObjectContext
+    var coreDataStack: CoreDataStack!
+    var testContext: NSManagedObjectContext!
     typealias PumpEvent = PumpEventStored.EventType
 
-    init() {
+    init() async throws {
         // Create test context
+        coreDataStack = try await CoreDataStack.createForTests()
         testContext = coreDataStack.newTaskContext()
 
         // Create assembler with test assembly

TrioTests/CoreDataTests/TempTargetStorageTests.swift

@@ -8,11 +8,12 @@ import Testing
 @Suite("TempTargetStorage Tests", .serialized) struct TempTargetsStorageTests: Injectable {
     @Injected() var storage: TempTargetsStorage!
     let resolver: Resolver
-    let coreDataStack = CoreDataStack.createForTests()
-    let testContext: NSManagedObjectContext
+    var coreDataStack: CoreDataStack!
+    var testContext: NSManagedObjectContext!
 
-    init() {
+    init() async throws {
         // Create test context
+        coreDataStack = try await CoreDataStack.createForTests()
         testContext = coreDataStack.newTaskContext()
 
         // Create assembler with test assembly
@@ -58,7 +59,7 @@ import Testing
         try await storage.storeTempTarget(tempTarget: testTarget)
 
         // Then verify stored entries
-        let storedEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let storedEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: TempTargetStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "name == %@", "Test Target"),
@@ -91,7 +92,7 @@ import Testing
         try await storage.storeTempTarget(tempTarget: testTarget)
 
         // Get the stored target's ObjectID
-        let storedEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let storedEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: TempTargetStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "name == %@", "Delete Test"),
@@ -107,7 +108,7 @@ import Testing
         await storage.deleteTempTargetPreset(objectID)
 
         // Then verify deletion
-        let remainingEntries = try await CoreDataStack.shared.fetchEntitiesAsync(
+        let remainingEntries = try await coreDataStack.fetchEntitiesAsync(
             ofType: TempTargetStored.self,
             onContext: testContext,
             predicate: NSPredicate(format: "name == %@", "Delete Test"),