A whole bunch of changes

test/purge_data_test.dart

@@ -0,0 +1,174 @@
+import 'dart:io';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:fuel_tax_tracker/models/fuel_entry.dart';
+import 'package:fuel_tax_tracker/models/vehicle.dart';
+import 'package:fuel_tax_tracker/services/database_service.dart';
+import 'package:path/path.dart' as p;
+import 'package:path_provider_platform_interface/path_provider_platform_interface.dart';
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+import 'package:sqflite_common_ffi/sqflite_ffi.dart';
+
+/// Both purge paths reuse the same soft-delete tombstones as a normal
+/// per-row delete (see [DatabaseService.softDeleteVehicle]) rather than a
+/// real SQL `DELETE`, specifically so the deletion is something a cloud
+/// sync can push to other devices instead of the rows just getting
+/// silently re-imported from the remote copy on the next sync.
+void main() {
+  late Directory tempDir;
+  late DatabaseService database;
+
+  setUpAll(() {
+    sqfliteFfiInit();
+    databaseFactory = databaseFactoryFfi;
+  });
+
+  setUp(() async {
+    tempDir = await Directory.systemTemp.createTemp('purge_data_test_');
+    PathProviderPlatform.instance = _FakePathProviderPlatform(tempDir.path);
+    database = DatabaseService();
+    await database.init();
+  });
+
+  tearDown(() async {
+    await database.rawDb.close();
+    await tempDir.delete(recursive: true);
+  });
+
+  Vehicle vehicle({required String id, required String vin}) => Vehicle(
+        id: id,
+        vin: vin,
+        updatedAt: DateTime.utc(2026, 1, 1),
+      );
+
+  FuelEntry entry({
+    required String id,
+    required String vehicleId,
+    required DateTime date,
+    String? receiptImagePath,
+  }) =>
+      FuelEntry(
+        id: id,
+        vehicleId: vehicleId,
+        date: date,
+        gallons: 10,
+        pricePerGallon: 3.5,
+        totalCost: 35,
+        updatedAt: DateTime.utc(2026, 1, 1),
+        receiptImagePath: receiptImagePath,
+      );
+
+  group('purgeAllData', () {
+    test('soft-deletes every active vehicle and fuel entry, marking them dirty', () async {
+      await database.saveVehicle(vehicle(id: 'v1', vin: 'VIN1'));
+      await database.saveVehicle(vehicle(id: 'v2', vin: 'VIN2'));
+      await database.saveFuelEntry(entry(id: 'e1', vehicleId: 'v1', date: DateTime(2026, 3, 1)));
+      await database.saveFuelEntry(entry(id: 'e2', vehicleId: 'v2', date: DateTime(2026, 4, 1)));
+
+      await database.purgeAllData(DateTime.utc(2026, 8, 13));
+
+      expect(await database.getVehicles(), isEmpty);
+      expect(await database.getFuelEntries(), isEmpty);
+
+      final vehicleRows = await database.rawDb.query('vehicles');
+      final entryRows = await database.rawDb.query('fuel_entries');
+      expect(vehicleRows, hasLength(2), reason: 'tombstoned, not hard-deleted');
+      expect(entryRows, hasLength(2));
+      for (final row in [...vehicleRows, ...entryRows]) {
+        expect(row['deleted_at'], isNotNull);
+        expect(row['dirty'], 1);
+      }
+    });
+
+    test('empties the local receipts folder, including untracked files', () async {
+      final source = File(p.join(tempDir.path, 'source.jpg'))..writeAsBytesSync([1, 2, 3]);
+      final storedPath =
+          await database.storeReceiptImage(source, 'e1', 'VIN1', DateTime(2026, 3, 1));
+      // Simulate an orphaned file the DB never referenced.
+      final strayFile = File(p.join(database.receiptsDirectory.path, 'stray.jpg'))
+        ..writeAsBytesSync([9]);
+
+      await database.purgeAllData(DateTime.utc(2026, 8, 13));
+
+      expect(await File(storedPath).exists(), isFalse);
+      expect(await strayFile.exists(), isFalse);
+      expect(await database.receiptsDirectory.exists(), isTrue,
+          reason: 'recreated empty, ready for future use');
+    });
+
+    test('leaves already-deleted rows alone', () async {
+      await database.saveVehicle(vehicle(id: 'v1', vin: 'VIN1'));
+      await database.softDeleteVehicle('v1', DateTime.utc(2026, 1, 2));
+
+      await database.purgeAllData(DateTime.utc(2026, 8, 13));
+
+      final rows = await database.rawDb.query('vehicles', where: 'id = ?', whereArgs: ['v1']);
+      expect(rows.single['deleted_at'], DateTime.utc(2026, 1, 2).millisecondsSinceEpoch);
+    });
+  });
+
+  group('purgeFuelEntriesInRange', () {
+    test('soft-deletes only entries dated within the inclusive range', () async {
+      await database.saveVehicle(vehicle(id: 'v1', vin: 'VIN1'));
+      await database.saveFuelEntry(
+        entry(id: 'before', vehicleId: 'v1', date: DateTime(2026, 2, 28)),
+      );
+      await database.saveFuelEntry(
+        entry(id: 'start-boundary', vehicleId: 'v1', date: DateTime(2026, 3, 1)),
+      );
+      await database.saveFuelEntry(
+        entry(id: 'inside', vehicleId: 'v1', date: DateTime(2026, 3, 15)),
+      );
+      await database.saveFuelEntry(
+        entry(id: 'end-boundary', vehicleId: 'v1', date: DateTime(2026, 3, 31)),
+      );
+      await database.saveFuelEntry(
+        entry(id: 'after', vehicleId: 'v1', date: DateTime(2026, 4, 1)),
+      );
+
+      await database.purgeFuelEntriesInRange(
+        DateTime(2026, 3, 1),
+        DateTime(2026, 3, 31),
+        DateTime.utc(2026, 8, 13),
+      );
+
+      final remaining = await database.getFuelEntries();
+      expect(remaining.map((e) => e.id).toSet(), {'before', 'after'});
+      expect(await database.getVehicles(), hasLength(1), reason: 'vehicles are untouched');
+    });
+
+    test('returns local receipt paths for the caller to delete, without touching untracked files',
+        () async {
+      await database.saveVehicle(vehicle(id: 'v1', vin: 'VIN1'));
+      final source = File(p.join(tempDir.path, 'source.jpg'))..writeAsBytesSync([1, 2, 3]);
+      final storedPath =
+          await database.storeReceiptImage(source, 'e1', 'VIN1', DateTime(2026, 3, 15));
+      await database.saveFuelEntry(
+        entry(id: 'e1', vehicleId: 'v1', date: DateTime(2026, 3, 15), receiptImagePath: storedPath),
+      );
+
+      final paths = await database.purgeFuelEntriesInRange(
+        DateTime(2026, 3, 1),
+        DateTime(2026, 3, 31),
+        DateTime.utc(2026, 8, 13),
+      );
+
+      expect(paths, [storedPath]);
+      // purgeFuelEntriesInRange only reports paths — deleting the files
+      // themselves is the caller's job (AppState), mirroring
+      // softDeleteFuelEntriesForVehicle.
+      expect(await File(storedPath).exists(), isTrue);
+    });
+  });
+}
+
+class _FakePathProviderPlatform extends PathProviderPlatform with MockPlatformInterfaceMixin {
+  final String tempPath;
+  _FakePathProviderPlatform(this.tempPath);
+
+  @override
+  Future<String?> getApplicationDocumentsPath() async => tempPath;
+
+  @override
+  Future<String?> getTemporaryPath() async => tempPath;
+}