Show a message when expenses list is empty

moneymgr_mobile/lib/routes/scans_list/scans_list_screen.dart

@@ -48,6 +48,12 @@ class _ExpensesList extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    if (list.isEmpty) {
+      return const Center(
+        child: Text("There is no entry waiting for upload (yet)"),
+      );
+    }
+
     return ListView.builder(
       itemBuilder: (context, entryNum) {
         final expense = list[entryNum];

moneymgr_mobile/lib/services/api/inbox_api.dart

@@ -0,0 +1,27 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+import 'api_client.dart';
+
+part 'inbox_api.freezed.dart';
+part 'inbox_api.g.dart';
+
+@freezed
+abstract class UpdateInboxEntryRequest with _$UpdateInboxEntryRequest {
+  const factory UpdateInboxEntryRequest({
+    // ignore: non_constant_identifier_names
+    required int file_id,
+    required int time,
+    required String? label,
+    required double? amount,
+  }) = _UpdateInboxEntryRequest;
+
+  factory UpdateInboxEntryRequest.fromJson(Map<String, dynamic> json) =>
+      _$UpdateInboxEntryRequestFromJson(json);
+}
+
+extension InboxApi on ApiClient {
+  /// Create a new inbox entry
+  Future<void> createInboxEntry(UpdateInboxEntryRequest entry) async {
+    await execute("/inbox", method: "POST", data: entry.toJson());
+  }
+}

moneymgr_mobile/lib/widgets/expense_editor.dart

@@ -65,6 +65,11 @@ class ExpenseEditor extends HookConsumerWidget {
           time: timeController.value,
         ),
       );
+
+      // Reset screen after a scan
+      await pending.value;
+      labelController.text = "";
+      costController.text = "";
     }
 
     // Cancel operation

moneymgr_mobile/lib/widgets/synchronize_button.dart

@@ -3,6 +3,7 @@ import 'package:hooks_riverpod/hooks_riverpod.dart';
 import 'package:logging/logging.dart';
 import 'package:moneymgr_mobile/services/api/api_client.dart';
 import 'package:moneymgr_mobile/services/api/files_api.dart';
+import 'package:moneymgr_mobile/services/api/inbox_api.dart';
 import 'package:moneymgr_mobile/services/storage/expenses.dart';
 import 'package:moneymgr_mobile/utils/extensions.dart';
 import 'package:moneymgr_mobile/utils/hooks.dart';
@@ -27,9 +28,21 @@ Future<void> _performSynchronization(Ref ref) async {
       bytes: bytes,
     );
 
-    // TODO continue
-    break;
+    // Then, create the inbox entry
+    await apiService.createInboxEntry(
+      UpdateInboxEntryRequest(
+        file_id: file.id,
+        time: exp.time,
+        label: exp.label,
+        amount: -1 * exp.cost,
+      ),
+    );
+
+    // Lastly delete the local expense
+    ref.watch(expensesProvider).requireValue.deleteExpense(exp);
   }
+
+  ref.invalidate(expensesProvider);
 }
 
 class SynchronizeButton extends HookConsumerWidget {