Refine iOS navigation, media controls, and background sync

ios/Runner/Native/SyncEngine/SyncCoordinator.swift

@@ -320,7 +320,13 @@ final class SyncCoordinator {
   /// exactly once - when the work ends or when the system's time does.
   private func handleBackground(_ task: BGTask) {
     scheduleBackgroundWork()  // line up the next one before this one runs
-    let gate = OnceGate { task.setTaskCompleted(success: $0) }
+    task.expirationHandler = startBackgroundSlot { task.setTaskCompleted(success: $0) }
+  }
+
+  /// Runs a background slot and returns its expiration handler.
+  @discardableResult
+  func startBackgroundSlot(completion: @escaping (Bool) -> Void) -> () -> Void {
+    let gate = OnceGate(completion)
     let accountIds = backgroundConfigs().map(\.accountId)
     let work = Task { [weak self] in
       guard let self else { return gate.finish(false) }
@@ -332,7 +338,7 @@ final class SyncCoordinator {
     }
     // The system's time is up: stop the work and the runs it started (each
     // saves what it has) and report.
-    task.expirationHandler = { [weak self] in
+    return { [weak self] in
       work.cancel()
       for id in accountIds { self?.cancelRun(accountId: id, invalidateQueued: false) }
       gate.finish(false)

ios/Runner/Native/SyncEngine/SyncDiff.swift

@@ -89,16 +89,7 @@ enum SyncDiff {
 
     for fileId in priorFolderFileIds where !seen.contains(fileId) {
       guard let prior = state[fileId] else { continue }
-      // Deleted on the server. If it was also edited here since the last sync
-      // that edit is the only copy left - keep it (untracked) instead of
-      // deleting it along with the rest.
-      if let local = LocalFS.stat(syncRoot.appendingPathComponent(prior.relPath)),
-        local.mtimeMs != prior.localMTime || local.size != prior.size
-      {
-        actions.append(.orphan(relPath: prior.relPath, fileId: fileId))
-      } else {
-        actions.append(.delete(relPath: prior.relPath, fileId: fileId))
-      }
+      actions.append(.delete(relPath: prior.relPath, fileId: fileId))
     }
     return actions
   }

ios/Runner/Native/SyncEngine/SyncModels.swift

@@ -38,10 +38,6 @@ enum SyncAction: Equatable {
   case upload(relPath: String, fileId: String)
   case delete(relPath: String, fileId: String)
   case conflict(SyncRemoteEntry, relPath: String)
-  /// Deleted on the server, but edited on this device since the last sync:
-  /// the edited copy is the only one left, so it's kept (and simply no longer
-  /// tracked) instead of being deleted with the rest. Android deletes it.
-  case orphan(relPath: String, fileId: String)
 }
 
 /// A file changed both on the device and on the server since the last sync.

ios/Runner/Native/SyncEngine/SyncRunner.swift

@@ -144,7 +144,7 @@ final class SyncStatusBus {
 ///   edits with the server's copies).
 /// - Paths the server sends are checked to stay inside the mirror, and two
 ///   remote files that would land on the same local file are both skipped.
-/// - A file deleted on the server but edited here is kept, not deleted.
+/// - Server deletions remove the local copy, including local edits, like Android.
 /// - A root's etag is only remembered once its whole path synced cleanly, and
 ///   only if the state it relies on was actually saved.
 struct SyncRunner {
@@ -301,11 +301,6 @@ struct SyncRunner {
             }
             state[fileId] = nil
 
-          case .orphan(_, let fileId):
-            // Deleted on the server but edited here: the edit stays on the
-            // device, no longer tracked.
-            state[fileId] = nil
-
           case .conflict(let entry, let rel):
             summary.conflicts.append(
               SyncConflict(

ios/RunnerTests/SyncEngineTests.swift

@@ -583,19 +583,19 @@ final class SyncEngineTests: XCTestCase {
     XCTAssertTrue(store.loadMissingRoots(accountId: "acct").isEmpty, "nor like the folder being gone")
   }
 
-  func testDeletedOnTheServerButEditedHereIsKept() async throws {
+  func testDeletedOnTheServerButEditedHereIsDeletedLikeAndroid() async throws {
     seedServer()
     _ = await runner.run(config, force: false)
     try editLocally("Docs/a.txt", "my only copy of this edit")
     FakeDav.remove("/Docs/a.txt")
 
     let summary = await runner.run(config, force: false)
-    XCTAssertEqual(summary.deleted, 0)
-    XCTAssertEqual(local("Docs/a.txt"), "my only copy of this edit")
+    XCTAssertEqual(summary.deleted, 1)
+    XCTAssertFalse(exists("Docs/a.txt"))
     XCTAssertNil(state().first { $0.value.relPath == "Docs/a.txt" }, "no longer tracked")
 
     let again = await runner.run(config, force: false)
-    XCTAssertEqual(local("Docs/a.txt"), "my only copy of this edit", "and not touched later either")
+    XCTAssertFalse(exists("Docs/a.txt"), "not restored on a later sync")
     XCTAssertFalse(again.changedAnything)
   }
 
@@ -740,6 +740,36 @@ final class SyncEngineTests: XCTestCase {
     XCTAssertEqual(bus.snapshot().conflicts, [b], "removing A's leaves B's")
   }
 
+  func testBackgroundSlotOnlyRunsAccountsWithPeriodicSyncEnabled() async {
+    seedServer()
+    let configs = SyncConfigStore(service: "test-\(UUID().uuidString)")
+    addTeardownBlock { configs.removeAll() }
+    let coordinator = SyncCoordinator(store: store, bus: bus, configs: configs, client: DavSyncClient(session: fakeSession))
+    var scheduled = config
+    scheduled.intervalMinutes = nil
+    scheduled.wifiOnly = false
+    configs.upsert(scheduled)
+
+    let skipped = expectation(description: "manual-only account skipped")
+    coordinator.startBackgroundSlot { success in
+      XCTAssertTrue(success)
+      skipped.fulfill()
+    }
+    await fulfillment(of: [skipped], timeout: 10)
+    XCTAssertFalse(exists("Docs/a.txt"))
+
+    scheduled.intervalMinutes = 30
+    configs.upsert(scheduled)
+    let completed = expectation(description: "periodic account synced")
+    coordinator.startBackgroundSlot { success in
+      XCTAssertTrue(success)
+      completed.fulfill()
+    }
+    await fulfillment(of: [completed], timeout: 15)
+    XCTAssertEqual(local("Docs/a.txt"), "alpha")
+    XCTAssertEqual(local("Docs/sub/b.txt"), "bravo")
+  }
+
   func testSignOutForgetsCredentialsButTurningBackgroundOffKeepsThem() {
     let service = "test-\(UUID().uuidString)"
     let configs = SyncConfigStore(service: service)