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

import 'package:doormile_cx/data/dev_doormile_api.dart';
import 'package:doormile_cx/data/doormile_api.dart';
import 'package:doormile_cx/data/models.dart';
import 'package:doormile_cx/state/app_scope.dart';
import 'package:doormile_cx/state/app_state.dart';
import 'package:doormile_cx/ui/screens/home_screen.dart';

/// ─────────────────────────────────────────────────────────────────────────
/// HOME SAYS HOW FAR DOORMILE GOES
///
/// One line under the sphere, and it has now failed to appear twice for two
/// different reasons — both silent, because an absent widget looks exactly
/// like a widget that decided it had nothing to say:
///
///  1. `cachedCities` walked every state in `statesCache`, including the ones
///     with no open districts, and `loadCities` only ever fetches districts for
///     the open ones. It found a hole and reported nothing cached. `loadCities`
///     returned eleven cities and the getter returned null beside it.
///  2. `loadCities` fills two caches and notifies nobody, so even once the data
///     was there Home never rebuilt to read it.
///
/// Neither would be caught by anything that checks the widget tree in
/// isolation, which is why this drives the real state object.
///
/// ── Two ways this file can hang rather than fail ──
///
/// The sphere breathes and its pulses repeat forever, so Home never settles:
/// `pumpAndSettle` does not fail here, it runs until the test times out ten
/// minutes later, which is a slow way to learn nothing. Fixed pumps instead.
///
/// And the dev API answers on a real timer while the widget binding's clock is
/// fake, so awaiting a load directly inside a `testWidgets` body waits on a
/// delay that will never elapse. Those go through `tester.runAsync`.
/// ─────────────────────────────────────────────────────────────────────────
void main() {
  late AppState app;

  setUp(() {
    DoormileApi.overrideInstance(DevDoormileApi());
    app = AppState()
      ..customer = const Customer(
        id: 'c1',
        name: 'Joe Oommen',
        phone: '+91 98765 43210',
        email: 'joe@example.com',
      );
  });

  tearDown(() => DoormileApi.overrideInstance(null));

  Future<void> pumpHome(WidgetTester tester) async {
    tester.view.physicalSize = const Size(1170, 2532);
    tester.view.devicePixelRatio = 3.0;
    addTearDown(tester.view.reset);

    // Inside a Scaffold, because `HomeScreen` does not carry one — it is a tab
    // root and `ShellScreen` owns the Scaffold for all three. Without it there
    // is no `Material` for the ink responses and no bounded width for the
    // greeting row, and the screen fails for two reasons that have nothing to
    // do with what is being tested.
    await tester.pumpWidget(
      AppScope(
        state: app,
        child: const MaterialApp(home: Scaffold(body: HomeScreen())),
      ),
    );
    for (var i = 0; i < 6; i++) {
      await tester.pump(const Duration(milliseconds: 120));
    }
  }

  group('the serviceable set', () {
    test('cachedCities agrees with loadCities', () async {
      expect(app.cachedCities, isNull, reason: 'nothing fetched yet');

      final loaded = await app.loadCities();
      expect(loaded, isNotEmpty);
      expect(
        app.cachedCities?.length,
        loaded.length,
        reason: 'the synchronous view must be the same set as the async one',
      );
    });

    test('it offers no district the picker would not', () async {
      final loaded = await app.loadCities();
      final cached = app.cachedCities!;

      final loadedCodes = {for (final c in loaded) c.district.code};
      final cachedCodes = {for (final c in cached) c.district.code};
      expect(cachedCodes, loadedCodes);
    });
  });

  group('the reach line', () {
    testWidgets('is absent until the cities are known', (tester) async {
      await pumpHome(tester);
      expect(find.textContaining('Delivering to'), findsNothing);
    });

    testWidgets('states the reach once they are', (tester) async {
      // `runAsync`, not a bare await: the dev API answers on a real timer and
      // the widget binding's clock is fake, so awaiting it directly inside a
      // `testWidgets` body waits for a delay that will never elapse.
      await tester.runAsync(() => app.loadCities());
      await pumpHome(tester);

      final line = find.textContaining('Delivering to');
      expect(line, findsOneWidget);

      final text = tester.widget<Text>(line).data!;
      final cities = app.cachedCities!;
      final states = <String>{for (final c in cities) c.state.code}.length;
      expect(text, contains('${cities.length}'));
      expect(text, contains('$states states'));
    });

    testWidgets('a rebuild after the warm-up is what makes it appear', (
      tester,
    ) async {
      // The order that used to fail: Home is already on screen when the
      // cities land. Nothing re-reads the cache unless the state says so.
      await pumpHome(tester);
      expect(find.textContaining('Delivering to'), findsNothing);

      await tester.runAsync(() => app.loadCities());
      app.notifyListeners();
      await tester.pump();

      expect(find.textContaining('Delivering to'), findsOneWidget);
    });
  });
}