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

import 'package:fuel_tax_tracker/screens/data_settings_screen.dart';
import 'package:fuel_tax_tracker/services/app_state.dart';

/// Covers the "Danger Zone" purge UI's warning-dialog gating, now folded
/// into the Settings > Data > Advanced section — the actual delete behavior
/// (soft-delete tombstones, dirty flags, receipt file cleanup) is covered
/// against a real database in purge_data_test.dart. This deliberately never
/// taps a dialog's destructive "Delete" button: doing so would call through
/// to [AppState.purgeAllData]/[AppState.purgeFuelEntriesInRange], which need
/// an initialized database — not set up here, matching every other Settings
/// widget test (see theme_toggle_test.dart) that stops short of a full
/// [AppState.init].
void main() {
  setUp(() {
    SharedPreferences.setMockInitialValues({});
  });

  Future<void> pumpSettings(WidgetTester tester, AppState appState) async {
    await tester.pumpWidget(
      ChangeNotifierProvider.value(
        value: appState,
        child: const MaterialApp(home: DataSettingsScreen()),
      ),
    );
  }

  // The purge controls sit inside the collapsed "Advanced" ExpansionTile,
  // below the fold — every test needs to expand it and scroll it into view
  // before tapping anything inside it.
  Future<void> scrollToDangerZone(WidgetTester tester) async {
    await tester.scrollUntilVisible(find.text('Advanced'), 200, scrollable: find.byType(Scrollable));
    await tester.tap(find.text('Advanced'));
    await tester.pumpAndSettle();
    await tester.scrollUntilVisible(find.text('Danger Zone'), 200, scrollable: find.byType(Scrollable));
    await tester.pumpAndSettle();
  }

  testWidgets('Purge All Data shows a warning dialog; Cancel dismisses it without purging',
      (tester) async {
    final appState = AppState()..isLoading = false;
    await pumpSettings(tester, appState);
    await scrollToDangerZone(tester);

    await tester.tap(find.widgetWithText(OutlinedButton, 'Purge All Data'));
    await tester.pumpAndSettle();

    expect(find.text('Purge all data?'), findsOneWidget);
    expect(find.textContaining("can't be undone"), findsOneWidget);

    await tester.tap(find.text('Cancel'));
    await tester.pumpAndSettle();

    expect(find.text('Purge all data?'), findsNothing);
    expect(appState.vehicles, isEmpty);
  });

  testWidgets('mentions the connected cloud provider in the warning when one is connected',
      (tester) async {
    final appState = AppState()..isLoading = false;
    await pumpSettings(tester, appState);
    await scrollToDangerZone(tester);

    await tester.tap(find.widgetWithText(OutlinedButton, 'Purge All Data'));
    await tester.pumpAndSettle();

    expect(find.textContaining('connected to'), findsNothing,
        reason: 'no cloud provider connected in this test');

    await tester.tap(find.text('Cancel'));
    await tester.pumpAndSettle();
  });

  testWidgets('Purge Range is disabled until both a start and end date are picked',
      (tester) async {
    final appState = AppState()..isLoading = false;
    await pumpSettings(tester, appState);
    await scrollToDangerZone(tester);

    final purgeRangeButton =
        tester.widget<OutlinedButton>(find.widgetWithText(OutlinedButton, 'Purge Range'));
    expect(purgeRangeButton.onPressed, isNull);
  });

  testWidgets('picking a start and end date enables Purge Range, which shows a warning dialog',
      (tester) async {
    final appState = AppState()..isLoading = false;
    await pumpSettings(tester, appState);
    await scrollToDangerZone(tester);

    await tester.tap(find.text('Start date'));
    await tester.pumpAndSettle();
    await tester.tap(find.text('OK'));
    await tester.pumpAndSettle();

    await tester.tap(find.text('End date'));
    await tester.pumpAndSettle();
    await tester.tap(find.text('OK'));
    await tester.pumpAndSettle();

    final purgeRangeButton =
        tester.widget<OutlinedButton>(find.widgetWithText(OutlinedButton, 'Purge Range'));
    expect(purgeRangeButton.onPressed, isNotNull);

    await tester.tap(find.widgetWithText(OutlinedButton, 'Purge Range'));
    await tester.pumpAndSettle();

    expect(find.text('Purge data in range?'), findsOneWidget);

    await tester.tap(find.text('Cancel'));
    await tester.pumpAndSettle();
  });
}