import 'package:flutter_test/flutter_test.dart';
import 'package:nearle_pos/data/datasources/local_store.dart';
import 'package:nearle_pos/data/local/staff_dao.dart';
import 'package:nearle_pos/domain/entities/store_account.dart';

/// The till shipped with three names and three PINs compiled into it —
/// Suriya/4821, Divya/5093, Rahul/6274 — identical on every install and
/// readable by anyone with the APK. They existed because a shop with nothing in
/// its back office still has to trade on day one, and that is still true: only
/// 116 of 596 accounts on the platform have a PIN, and the outlet this build
/// ships pointed at has none at all.
///
/// So they stay, as a last resort, and these cover the thing that makes that
/// safe: real staff must *retire* them rather than sit alongside them.
StaffDao get staff => LocalStore.instance.staff;

void main() {
  TestWidgetsFlutterBinding.ensureInitialized();

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

  test('a fresh till has the seeded accounts and they work', () async {
    final seeded = await staff.all();

    expect(seeded, hasLength(3));
    expect(await staff.authenticate('4821'), isNotNull);
    // Every one is flagged, so the first person in is made to change it.
    expect(seeded.every((s) => s.mustChangePin), isTrue);
  });

  test('real staff retire the built-in PINs', () async {
    // The whole point. Without this the hardcoded logins would survive next to
    // the real ones for ever, on every terminal in the fleet.
    await staff.replaceFromBackOffice(const [
      StaffImportRecord(
        localId: 'boffice-1229',
        name: 'Selvapuram',
        role: StaffRole.manager,
        pin: '7391',
      ),
    ]);

    expect(await staff.authenticate('7391'), isNotNull,
        reason: 'the imported account must work');
    expect(await staff.authenticate('4821'), isNull,
        reason: 'Suriya was compiled into the app and must be gone');
    expect(await staff.authenticate('5093'), isNull);
    expect(await staff.authenticate('6274'), isNull);
  });

  test('an empty answer leaves a working till alone', () async {
    // The common case: most outlets have nobody recorded. Wiping the logins
    // because the back office has not been filled in yet would close a shop.
    final written = await staff.replaceFromBackOffice(const []);

    expect(written, 0);
    expect(await staff.authenticate('4821'), isNotNull);
  });

  test('a leaver loses the till on the next sign-in', () async {
    await staff.replaceFromBackOffice(const [
      StaffImportRecord(
          localId: 'boffice-1', name: 'Asha', role: StaffRole.cashier, pin: '7391'),
      StaffImportRecord(
          localId: 'boffice-2', name: 'Ravi', role: StaffRole.cashier, pin: '8402'),
    ]);
    expect(await staff.authenticate('8402'), isNotNull);

    // Ravi is removed in the back office.
    await staff.replaceFromBackOffice(const [
      StaffImportRecord(
          localId: 'boffice-1', name: 'Asha', role: StaffRole.cashier, pin: '7391'),
    ]);

    expect(await staff.authenticate('7391'), isNotNull);
    expect(await staff.authenticate('8402'), isNull);
  });

  test('re-syncing the same person updates rather than duplicates', () async {
    // Keyed on the back office user id, so a shop that changes somebody's PIN
    // gets one account with a new PIN, not two accounts with one each.
    await staff.replaceFromBackOffice(const [
      StaffImportRecord(
          localId: 'boffice-1', name: 'Asha', role: StaffRole.cashier, pin: '7391'),
    ]);
    await staff.replaceFromBackOffice(const [
      StaffImportRecord(
          localId: 'boffice-1', name: 'Asha Kumar', role: StaffRole.manager, pin: '8402'),
    ]);

    final all = await staff.all();
    expect(all, hasLength(1));
    expect(all.single.name, 'Asha Kumar');
    expect(all.single.role, StaffRole.manager);
    expect(await staff.authenticate('8402'), isNotNull);
    expect(await staff.authenticate('7391'), isNull);
  });

  test('an imported PIN is not flagged for change', () async {
    // It was set by the shop in the back office, so it is already theirs. The
    // flag is for the seeds, which everyone shares.
    await staff.replaceFromBackOffice(const [
      StaffImportRecord(
          localId: 'boffice-1', name: 'Asha', role: StaffRole.cashier, pin: '7391'),
    ]);

    final imported = await staff.authenticate('7391');
    expect(imported!.mustChangePin, isFalse);
  });

  test('an unusable PIN is skipped rather than written', () async {
    // A name on screen that nobody can sign in as reads as a broken terminal.
    // `pin = 0` is the single most common value in app_users.
    await staff.replaceFromBackOffice(const [
      StaffImportRecord(
          localId: 'boffice-1', name: 'No PIN', role: StaffRole.cashier, pin: '0'),
      StaffImportRecord(
          localId: 'boffice-2', name: 'Blank', role: StaffRole.cashier, pin: ''),
      StaffImportRecord(
          localId: 'boffice-3', name: 'Usable', role: StaffRole.cashier, pin: '7391'),
    ]);

    final all = await staff.all();
    expect(all, hasLength(1));
    expect(all.single.name, 'Usable');
  });

  test('an answer of nothing usable does not strand the till', () async {
    // Every row unusable is not the same as a deliberate empty list, but it has
    // to behave the same way — otherwise a back office full of `pin = 0` rows
    // would deactivate the seeds and leave nobody able to sign in.
    final written = await staff.replaceFromBackOffice(const [
      StaffImportRecord(
          localId: 'boffice-1', name: 'No PIN', role: StaffRole.cashier, pin: '0'),
    ]);

    expect(written, 0);
    expect(await staff.authenticate('4821'), isNotNull,
        reason: 'the seeds must survive an import that wrote nobody');
  });
}