import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:provider/provider.dart';
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';

import 'package:fuel_tax_tracker/models/fuel_entry.dart';
import 'package:fuel_tax_tracker/models/vehicle.dart';
import 'package:fuel_tax_tracker/screens/edit_fuel_entry_screen.dart';
import 'package:fuel_tax_tracker/screens/receipt_detail_screen.dart';
import 'package:fuel_tax_tracker/screens/vehicle_detail_screen.dart';
import 'package:fuel_tax_tracker/services/app_state.dart';
import 'package:fuel_tax_tracker/services/database_service.dart';

/// Covers editing a fuel entry's logged data (date/gallons/price/total) —
/// not its receipt photo, which [EditFuelEntryScreen] deliberately shows
/// read-only. The database-level overwrite semantics ([DatabaseService]
/// group) are what [AppState.updateFuelEntry] relies on: it just calls
/// [DatabaseService.saveFuelEntry] again with the same id, same as any
/// other upsert in this app (see [DatabaseService.saveVehicle]).
void main() {
  final vehicle = Vehicle(id: 'v1', vin: '1FMPU18L1TLB51349', updatedAt: DateTime.utc(2026, 1, 1));
  final otherVehicle =
      Vehicle(id: 'v2', vin: '1HGCM82633A004352', nickname: 'Second Car', updatedAt: DateTime.utc(2026, 1, 1));
  final entry = FuelEntry(
    id: 'e1',
    vehicleId: 'v1',
    date: DateTime(2026, 3, 5, 14, 30),
    gallons: 10.5,
    pricePerGallon: 3.499,
    totalCost: 36.74,
    updatedAt: DateTime.utc(2026, 3, 5),
  );

  group('DatabaseService.saveFuelEntry overwrite semantics', () {
    late Directory tempDir;
    late DatabaseService database;

    setUpAll(() {
      sqfliteFfiInit();
      databaseFactory = databaseFactoryFfi;
    });

    setUp(() async {
      tempDir = await Directory.systemTemp.createTemp('edit_fuel_entry_test_');
      PathProviderPlatform.instance = _FakePathProviderPlatform(tempDir.path);
      database = DatabaseService();
      await database.init();
    });

    tearDown(() async {
      await database.rawDb.close();
      await tempDir.delete(recursive: true);
    });

    test('saving again with the same id overwrites gallons/price/total/date, marking it dirty',
        () async {
      await database.saveVehicle(vehicle);
      await database.saveFuelEntry(entry);
      // Clear the dirty flag the way a completed sync would, so the
      // overwrite below can prove it gets re-marked dirty.
      await database.rawDb.update('fuel_entries', {'dirty': 0}, where: 'id = ?', whereArgs: ['e1']);

      await database.saveFuelEntry(FuelEntry(
        id: 'e1',
        vehicleId: 'v1',
        date: DateTime(2026, 3, 6, 9, 0),
        gallons: 11.2,
        pricePerGallon: 3.599,
        totalCost: 40.31,
        updatedAt: DateTime.utc(2026, 3, 6),
      ));

      final rows = await database.getFuelEntries();
      expect(rows, hasLength(1), reason: 'overwritten, not duplicated');
      final saved = rows.single;
      expect(saved.gallons, 11.2);
      expect(saved.pricePerGallon, 3.599);
      expect(saved.totalCost, 40.31);
      expect(saved.date, DateTime(2026, 3, 6, 9, 0));

      final rawRow = (await database.rawDb.query('fuel_entries', where: 'id = ?', whereArgs: ['e1'])).single;
      expect(rawRow['dirty'], 1);
    });

    test('saving again with a different vehicleId moves the entry to that vehicle', () async {
      await database.saveVehicle(vehicle);
      await database.saveVehicle(otherVehicle);
      await database.saveFuelEntry(entry);

      await database.saveFuelEntry(FuelEntry(
        id: entry.id,
        vehicleId: otherVehicle.id,
        date: entry.date,
        gallons: entry.gallons,
        pricePerGallon: entry.pricePerGallon,
        totalCost: entry.totalCost,
        updatedAt: DateTime.utc(2026, 3, 6),
      ));

      final saved = (await database.getFuelEntries()).single;
      expect(saved.vehicleId, otherVehicle.id);
    });
  });

  group('EditFuelEntryScreen', () {
    Future<void> pumpVehicleDetail(WidgetTester tester, AppState appState) async {
      await tester.pumpWidget(
        ChangeNotifierProvider.value(
          value: appState,
          child: MaterialApp(home: VehicleDetailScreen(vehicleId: vehicle.id)),
        ),
      );
    }

    testWidgets(
        'tapping an entry row opens its receipt detail page, and its edit icon opens '
        'EditFuelEntryScreen pre-filled', (tester) async {
      final appState = AppState()
        ..isLoading = false
        ..vehicles = [vehicle]
        ..fuelEntries = [entry];

      await pumpVehicleDetail(tester, appState);

      await tester.tap(find.text('10.500 gal • \$36.74'));
      await tester.pumpAndSettle();

      expect(find.byType(ReceiptDetailScreen), findsOneWidget);

      await tester.tap(find.byTooltip('Edit fuel entry'));
      await tester.pumpAndSettle();

      expect(find.byType(EditFuelEntryScreen), findsOneWidget);
      expect(find.widgetWithText(TextFormField, '10.500'), findsOneWidget);
      expect(find.widgetWithText(TextFormField, '3.499'), findsOneWidget);
      expect(find.widgetWithText(TextFormField, '36.74'), findsOneWidget);
    });

    testWidgets('clearing a required field shows a validation error instead of saving',
        (tester) async {
      final appState = AppState()
        ..isLoading = false
        ..vehicles = [vehicle]
        ..fuelEntries = [entry];

      await tester.pumpWidget(
        ChangeNotifierProvider.value(
          value: appState,
          child: MaterialApp(home: EditFuelEntryScreen(entry: entry)),
        ),
      );

      await tester.enterText(find.widgetWithText(TextFormField, '10.500'), '');
      await tester.drag(find.byType(ListView), const Offset(0, -300));
      await tester.pumpAndSettle();
      await tester.tap(find.widgetWithText(FilledButton, 'Save Changes'));
      await tester.pumpAndSettle();

      expect(find.text('Required'), findsOneWidget);
      expect(find.byType(EditFuelEntryScreen), findsOneWidget, reason: 'did not navigate away');
    });

    testWidgets('shows a vehicle picker pre-selected to the entry\'s current vehicle',
        (tester) async {
      final appState = AppState()
        ..isLoading = false
        ..vehicles = [vehicle, otherVehicle]
        ..fuelEntries = [entry];

      await tester.pumpWidget(
        ChangeNotifierProvider.value(
          value: appState,
          child: MaterialApp(home: EditFuelEntryScreen(entry: entry)),
        ),
      );

      expect(find.widgetWithText(DropdownButtonFormField<String>, vehicle.displayLabel),
          findsOneWidget);
    });

    testWidgets('picking a different vehicle updates the selection shown', (tester) async {
      final appState = AppState()
        ..isLoading = false
        ..vehicles = [vehicle, otherVehicle]
        ..fuelEntries = [entry];

      await tester.pumpWidget(
        ChangeNotifierProvider.value(
          value: appState,
          child: MaterialApp(home: EditFuelEntryScreen(entry: entry)),
        ),
      );

      await tester.tap(find.byType(DropdownButtonFormField<String>));
      await tester.pumpAndSettle();
      // Two matches once the menu is open: the closed field's current
      // selection, and the same label repeated as a menu item.
      await tester.tap(find.text(otherVehicle.displayLabel).last);
      await tester.pumpAndSettle();

      expect(find.widgetWithText(DropdownButtonFormField<String>, otherVehicle.displayLabel),
          findsOneWidget);
      expect(find.widgetWithText(DropdownButtonFormField<String>, vehicle.displayLabel),
          findsNothing);
    });
  });
}

class _FakePathProviderPlatform extends PathProviderPlatform with MockPlatformInterfaceMixin {
  final String tempPath;
  _FakePathProviderPlatform(this.tempPath);

  @override
  Future<String?> getApplicationDocumentsPath() async => tempPath;

  @override
  Future<String?> getTemporaryPath() async => tempPath;
}