Keep Monero scan progress across app restarts

apps/ios/Koins/AppModel.swift

@@ -21,6 +21,7 @@ final class AppModel: ObservableObject {
   private var refreshTick = 0
   private var refreshTask: Task<Void, Never>?
   private var lastSample: (height: UInt64, date: Date)?
+  private var lastCheckpoint = Date.distantPast
 
   var wallet: WalletRecord? {
     chain == .xrp ? xrpWallet : xmrWallet
@@ -212,6 +213,7 @@ final class AppModel: ObservableObject {
       // progress current here too.
       if moneroReady, let status = try? await MoneroService.shared.syncStatus() {
         updateSyncStatus(status)
+        await checkpointWalletIfSyncing()
       }
       return
     }
@@ -222,6 +224,7 @@ final class AppModel: ObservableObject {
       // list touch the wallet's data files, so they are refreshed less often.
       updateSyncStatus(try await MoneroService.shared.syncStatus())
       refreshTick += 1
+      await checkpointWalletIfSyncing()
       if force || refreshTick == 1 || refreshTick % 4 == 0 {
         async let balanceCall = MoneroService.shared.balance()
         async let txCall = MoneroService.shared.transactions()
@@ -334,4 +337,20 @@ final class AppModel: ObservableObject {
     errorMessage = nil
     statusMessage = nil
   }
+
+  /// Called when the app leaves the foreground: iOS can suspend or kill it at
+  /// any point, so flush the wallet while there is still time.
+  func persistWallet() async {
+    guard moneroReady else { return }
+    await MoneroService.shared.save()
+  }
+
+  /// monero-cpp only writes the wallet file from save(), and its sync loop
+  /// never does, so without this a restart re-scans from the beginning.
+  private func checkpointWalletIfSyncing() async {
+    guard moneroReady, syncStatus?.syncing == true else { return }
+    guard Date().timeIntervalSince(lastCheckpoint) >= 60 else { return }
+    lastCheckpoint = Date()
+    await MoneroService.shared.save()
+  }
 }

apps/ios/Koins/Bridge/KoinsMoneroWallet.mm

@@ -145,6 +145,16 @@ static void connectDaemon(monero_wallet_full *w) {
           delete g_wallet;
           g_wallet = nullptr;
         }
+      } else if ([op isEqualToString:@"saveWallet"]) {
+        // monero-cpp never persists while syncing, so scan progress survives a
+        // restart only if this is called explicitly. save() pauses the sync
+        // thread while it writes.
+        if (g_wallet) {
+          g_wallet->save();
+          resp[@"saved"] = @YES;
+        } else {
+          resp[@"error"] = @"No wallet open";
+        }
       } else if ([op isEqualToString:@"getBalance"]) {
         if (g_wallet) {
           uint64_t balance = 0, unlocked = 0;

apps/ios/Koins/Views/RootView.swift

@@ -17,6 +17,7 @@ struct SeedBox: Identifiable {
 
 struct RootView: View {
   @EnvironmentObject private var model: AppModel
+  @Environment(\.scenePhase) private var scenePhase
   @State private var route: Route = .home
   @State private var seedBox: SeedBox?
 
@@ -54,6 +55,11 @@ struct RootView: View {
     .onChange(of: model.chain) { _ in
       if route == .dashboard { route = .home }
     }
+    .onChange(of: scenePhase) { phase in
+      if phase != .active {
+        Task { await model.persistWallet() }
+      }
+    }
   }
 }
 
@@ -158,6 +164,26 @@ struct HomeView: View {
         }
       }
 
+      if model.chain == .xrp, model.moneroReady, let status = model.syncStatus, status.syncing {
+        Card {
+          VStack(alignment: .leading, spacing: 8) {
+            HStack(spacing: 8) {
+              Circle()
+                .fill(status.connected ? Theme.success : Theme.danger)
+                .frame(width: 7, height: 7)
+              Text("Monero is syncing in the background")
+                .font(.system(size: 12, weight: .medium))
+                .foregroundStyle(Theme.text)
+              Spacer()
+              Text("\(Int(status.progress * 100))%")
+                .font(.system(size: 12, weight: .semibold))
+                .foregroundStyle(Theme.muted)
+            }
+            SyncProgress(status: status, eta: model.syncEta)
+          }
+        }
+      }
+
       HStack(spacing: 10) {
         SecondaryButton(title: "Refresh") { Task { await model.refresh(force: true) } }
         SecondaryButton(title: "Delete") { showDeleteConfirm = true }
@@ -183,25 +209,6 @@ struct HomeView: View {
           .foregroundStyle(Theme.muted)
       }
 
-      if model.chain == .xrp, model.moneroReady, let status = model.syncStatus, status.syncing {
-        Card {
-          VStack(alignment: .leading, spacing: 8) {
-            HStack(spacing: 8) {
-              Circle()
-                .fill(status.connected ? Theme.success : Theme.danger)
-                .frame(width: 7, height: 7)
-              Text("Monero is syncing in the background")
-                .font(.system(size: 12, weight: .medium))
-                .foregroundStyle(Theme.text)
-              Spacer()
-              Text("\(Int(status.progress * 100))%")
-                .font(.system(size: 12, weight: .semibold))
-                .foregroundStyle(Theme.muted)
-            }
-            SyncProgress(status: status, eta: model.syncEta)
-          }
-        }
-      }
     }
   }
 

apps/ios/Koins/Wallet/MoneroService.swift

@@ -158,6 +158,11 @@ final class MoneroService {
     _ = try? await invoke(["op": "closeWallet"])
   }
 
+  /// Writes the wallet file, which is how scan progress survives a restart.
+  func save() async {
+    _ = try? await invoke(["op": "saveWallet"])
+  }
+
   func seed() async throws -> String {
     let response = try await invoke(["op": "getSeed"])
     return response["mnemonic"] as? String ?? ""