Localized Asset Packs with Managed Background Assets

 import SwiftUI
 import BackgroundAssets
 
−// Pre-iOS 27: no localized asset pack support in the manifest;
−// all language variants were downloaded regardless of the user's language setting.
−// Developers had to manually partition assets and manage downloads themselves.
+// Model representing a single asset pack download state
+struct AssetPackState: Identifiable {
+    let id: String
+    var fractionCompleted: Double
+    var isFinished: Bool
+}
 
 @MainActor
−class LegacyAssetViewModel: ObservableObject {
−    @Published var downloadedBytes: Int64 = 0
−    @Published var totalBytes: Int64 = 1
+class AssetPackViewModel: ObservableObject {
+    @Published var packs: [AssetPackState] = []
+    @Published var errorMessage: String?
 
−    // BADownloadManager existed pre-iOS 27 but lacked language-tag awareness
−    func beginDownload() {
−        // All language asset packs would be enqueued — no system-level locale filtering
−        let url = URL(string: "https://example.com/assets-all-languages.pack")!
−        var request = URLRequest(url: url)
−        let download = BAURLDownload(
−            identifier: "com.example.thecoast.assets.all",
−            request: request,
−            fileSize: 500_000_000, // 500 MB — all languages bundled
−            applicationGroupIdentifier: "group.com.example.thecoast"
−        )
−        BADownloadManager.shared.startForegroundDownload(download)
+    // BAAppExtensionInfo is the entry point for querying managed asset packs
+    private let manager = BAAppExtensionInfo()
+
+    func loadPackStatus() async {
+        // Fetch all asset packs the system knows about for this app
+        do {
+            let assetPacks = try await BAAppExtensionInfo.assetPacks()
+            for pack in assetPacks {
+                let state = AssetPackState(
+                    id: pack.identifier,
+                    fractionCompleted: pack.fractionCompleted,
+                    isFinished: pack.state == .installed
+                )
+                packs.append(state)
+            }
+        } catch {
+            errorMessage = error.localizedDescription
+        }
     }
+
+    func downloadPack(identifier: String) async {
+        do {
+            // Request a specific asset pack by identifier (language-tagged in manifest)
+            let request = BAURLDownload(identifier: identifier,
+                                        request: URLRequest(url: URL(string: "https://example.com")!),
+                                        fileSize: 0,
+                                        applicationGroupIdentifier: "group.com.example.thecoast")
+            BADownloadManager.shared.startForegroundDownload(request)
+        }
+    }
 }
 
−struct LegacyAssetView: View {
−    @StateObject private var vm = LegacyAssetViewModel()
+struct AssetPackDashboardView: View {
+    @StateObject private var viewModel = AssetPackViewModel()
 
     var body: some View {
−        VStack(spacing: 16) {
−            Text("Downloading all language assets…")
−            ProgressView(value: Double(vm.downloadedBytes),
−                         total: Double(vm.totalBytes))
−            Button("Start Download") { vm.beginDownload() }
+        NavigationStack {
+            List(viewModel.packs) { pack in
+                VStack(alignment: .leading, spacing: 6) {
+                    Text(pack.id)
+                        .font(.headline)
+                    if pack.isFinished {
+                        Label("Installed", systemImage: "checkmark.circle.fill")
+                            .foregroundStyle(.green)
+                    } else {
+                        ProgressView(value: pack.fractionCompleted)
+                        Text("\(Int(pack.fractionCompleted * 100))% downloaded")
+                            .font(.caption)
+                            .foregroundStyle(.secondary)
+                    }
+                }
+                .padding(.vertical, 4)
+            }
+            .navigationTitle("Asset Packs")
+            .task {
+                await viewModel.loadPackStatus()
+            }
+            .overlay {
+                if let error = viewModel.errorMessage {
+                    ContentUnavailableView(error,
+                                          systemImage: "exclamationmark.triangle")
+                }
+            }
         }
−        .padding()
     }
 }
 
 #Preview {
−    LegacyAssetView()
+    AssetPackDashboardView()
 }