import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:nearle_pos/app/providers.dart';
import 'package:nearle_pos/data/datasources/local_store.dart';
import 'package:nearle_pos/data/datasources/seed_data.dart';
import 'package:nearle_pos/domain/entities/store_account.dart';
import 'package:nearle_pos/presentation/auth/providers/auth_controller.dart';
import 'package:nearle_pos/presentation/modules/widgets/staff_dialogs.dart';
import 'package:nearle_pos/presentation/modules/widgets/store_details_dialog.dart';

/// The two admin screens that change what a till is and who may use it.
///
/// Both guard on role, and both refuse input that would break something a shop
/// cannot recover from on its own — a locked-out account, or a GSTIN that is
/// wrong on every invoice printed after it.
void main() {
  setUpAll(() {
    GoogleFonts.config.allowRuntimeFetching = false;
    LocalStore.registerSeed(
      products: SeedData.products,
      customers: SeedData.customers,
    );
  });

  setUp(() async {
    await LocalStore.instance.reset(withCatalogue: true);
  });

  const admin = StaffUser(id: 'u1', name: 'Suriya', role: StaffRole.admin);
  const cashier = StaffUser(id: 'u3', name: 'Rahul', role: StaffRole.cashier);

  StoreAccount storeWith(List<StaffUser> staff) => StoreAccount(
        id: 'store-001',
        name: 'Nearle Daily',
        email: 'admin@nearle.in',
        address: '1 Test Street',
        gstin: '33AABCU9603R1ZM',
        phone: '9840000000',
        staff: staff,
      );

  /// Mounts a dialog with [who] signed in.
  Future<void> open(
    WidgetTester tester, {
    required StaffUser who,
    required Future<void> Function(BuildContext) show,
    List<StaffUser> staff = const [admin, cashier],
  }) async {
    await tester.pumpWidget(
      ProviderScope(
        overrides: [
          storeAccountProvider.overrideWith((ref) async => storeWith(staff)),
          authControllerProvider.overrideWith(
            (ref) => _StubAuth(storeWith(staff), who),
          ),
        ],
        child: MaterialApp(
          home: Builder(
            builder: (context) => Scaffold(
              body: TextButton(
                onPressed: () => show(context),
                child: const Text('open'),
              ),
            ),
          ),
        ),
      ),
    );

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

  group('staff', () {
    testWidgets('a cashier is refused', (tester) async {
      // Anyone who can edit staff can make themselves an admin, so the check
      // has to be at the door rather than on each action.
      await open(tester, who: cashier, show: showStaffDialog);

      expect(find.textContaining('Only an admin'), findsOneWidget);
      expect(find.text('Add staff member'), findsNothing);
    });

    testWidgets('an admin can manage staff', (tester) async {
      await open(tester, who: admin, show: showStaffDialog);

      expect(find.text('Add staff member'), findsOneWidget);
      expect(find.text('Suriya'), findsOneWidget);
      expect(find.text('Rahul'), findsOneWidget);
    });

    testWidgets('a mistyped confirmation is caught before it locks an account',
        (tester) async {
      // There is no email to reset a PIN with. A typo nobody can verify means
      // the account is simply gone until an admin resets it.
      await open(tester, who: admin, show: showStaffDialog);

      await tester.tap(find.text('Add staff member'));
      await tester.pumpAndSettle();

      await tester.enterText(find.byType(TextFormField).first, 'Meena');
      await tester.enterText(find.byType(TextFormField).at(1), '7391');
      await tester.enterText(find.byType(TextFormField).at(2), '7392');

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

      expect(find.text('The two PINs do not match'), findsOneWidget);
    });

    testWidgets('a too-short PIN is refused', (tester) async {
      await open(tester, who: admin, show: showStaffDialog);
      await tester.tap(find.text('Add staff member'));
      await tester.pumpAndSettle();

      await tester.enterText(find.byType(TextFormField).first, 'Meena');
      await tester.enterText(find.byType(TextFormField).at(1), '73');
      await tester.enterText(find.byType(TextFormField).at(2), '73');

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

      expect(find.text('At least four digits'), findsOneWidget);
    });

    testWidgets('an account still on a shipped PIN is flagged', (tester) async {
      await open(
        tester,
        who: admin,
        show: showStaffDialog,
        staff: const [
          admin,
          StaffUser(
            id: 'u9',
            name: 'Newbie',
            role: StaffRole.cashier,
            mustChangePin: true,
          ),
        ],
      );

      expect(find.byIcon(Icons.warning_amber_rounded), findsOneWidget);
    });
  });

  group('store details', () {
    testWidgets('a cashier cannot change what invoices claim', (tester) async {
      await open(tester, who: cashier, show: showStoreDetailsDialog);
      expect(find.textContaining('Only an admin'), findsOneWidget);
    });

    testWidgets('a malformed GSTIN is refused', (tester) async {
      // It prints on every invoice as a legal requirement, so a typo is a
      // compliance problem across hundreds of bills before anyone notices.
      await open(tester, who: admin, show: showStoreDetailsDialog);

      await tester.enterText(find.byType(TextFormField).at(2), '99AABCU9603R1ZM');
      await tester.tap(find.text('Save'));
      await tester.pumpAndSettle();

      expect(
        find.text('The first two digits are not a valid state code.'),
        findsOneWidget,
      );
    });

    testWidgets('an empty seller name is refused', (tester) async {
      await open(tester, who: admin, show: showStoreDetailsDialog);

      await tester.enterText(find.byType(TextFormField).first, '');
      await tester.tap(find.text('Save'));
      await tester.pumpAndSettle();

      expect(find.text('An invoice must name the seller'), findsOneWidget);
    });
  });
}

/// Holds a fixed session so a test can choose who is signed in.
class _StubAuth extends AuthController {
  _StubAuth(StoreAccount store, StaffUser user) : super(_throwingRef) {
    state = Authenticated(store: store, user: user);
  }

  @override
  Future<void> refreshStore() async {}
}

/// The stub never reaches the real container, so a Ref is never used.
final Ref _throwingRef = _UnusedRef();

class _UnusedRef implements Ref {
  @override
  dynamic noSuchMethod(Invocation invocation) =>
      throw UnsupportedError('The stubbed AuthController does not read providers.');
}