import 'package:flutter_test/flutter_test.dart';
import 'package:halkyon_learn_flutter/src/app/instance_gate.dart';
import 'package:halkyon_learn_flutter/src/app/person_app.dart';
import 'package:halkyon_learn_flutter/src/core/instance/instance.dart';
import 'package:halkyon_learn_flutter/src/core/instance/instance_choice.dart';
import 'package:halkyon_learn_flutter/src/feature/auth/widget/session_gate.dart';
import 'package:halkyon_learn_flutter/src/feature/settings/widget/settings_screen.dart';
import 'package:material_ui/material_ui.dart';

import '../support/fake_instance_checker.dart';
import '../support/memory_device_settings_store.dart';
import '../support/memory_instance_store.dart';
import '../support/pump_app.dart';
import '../support/test_dependencies.dart';

void main() {
  final builtIn = Instance.parse('learn.halkyon.eu')!;
  final other = Instance.parse('learn.example.org')!;
  late MemoryInstanceStore store;
  late List<Instance> opened;
  late List<Instance> forgotten;

  setUp(() {
    store = MemoryInstanceStore();
    opened = [];
    forgotten = [];
  });

  /// Starts the app on a device that [usedBefore] the choice existed, with
  /// [answering] instances answering a check.
  Future<InstanceChoice> start(
    WidgetTester tester, {
    bool usedBefore = false,
    Set<Instance> answering = const {},
  }) async {
    tester.view.physicalSize = const Size(412, 900);
    tester.view.devicePixelRatio = 1;
    addTearDown(tester.view.reset);
    final choice = InstanceChoice(
      store,
      builtIn: builtIn,
      forget: (instance) async => forgotten.add(instance),
    );
    await choice.load(usedBefore: usedBefore);
    await tester.pumpWidget(
      InstanceGate(
        choice: choice,
        checker: FakeInstanceChecker(answering),
        deviceSettings: MemoryDeviceSettingsStore(),
        open: (instance) async {
          opened.add(instance);
          return testDependencies();
        },
        app: SessionGate(app: (person) => PersonApp(person: person)),
      ),
    );
    await tester.pumpAndSettle();
    return choice;
  }

  /// Opens Settings › Switch account, further down Settings.
  Future<void> openSwitcher(WidgetTester tester) async {
    await openTab(tester, 'Profile');
    await tester.tap(find.byTooltip('Settings'));
    await tester.pumpAndSettle();
    await tester.scrollUntilVisible(
      find.text('Switch account'),
      200,
      // Settings' list; its citation preview is a scroll view of its own.
      scrollable: find
          .descendant(
            of: find.byType(SettingsScreen),
            matching: find.byType(Scrollable),
          )
          .first,
    );
    // Built, but perhaps still below the window's edge.
    await tester.ensureVisible(find.text('Switch account'));
    await tester.pumpAndSettle();
    await tester.tap(find.text('Switch account'));
    await tester.pumpAndSettle();
  }

  testWidgets('a new install asks for the instance first, and opens the '
      "build's in one tap", (tester) async {
    await start(tester);

    // The wordmark says it to screen readers.
    expect(find.bySemanticsLabel('Welcome to Halkyon Learn'), findsOneWidget);
    expect(opened, isEmpty, reason: 'nothing made anywhere yet');
    expect(find.byType(TextField), findsNothing, reason: 'no address asked');

    await tester.tap(find.text('learn.halkyon.eu'));
    await tester.pumpAndSettle();

    expect(opened, [builtIn]);
    expect(tab('Home'), findsOneWidget);
  });

  testWidgets('another instance is checked before the app moves there', (
    tester,
  ) async {
    await start(tester, answering: {other});

    await tester.tap(find.text('Another instance'));
    await tester.pumpAndSettle();
    expect(
      FocusManager.instance.primaryFocus?.context
          ?.findAncestorWidgetOfExactType<TextField>(),
      isNotNull,
      reason: 'the address is typed at once',
    );

    await tester.enterText(find.byType(TextField), 'nowhere.example.org');
    await tester.tap(find.text('Continue'));
    await tester.pumpAndSettle();
    expect(
      find.text(
        'No instance of Halkyon Learn answers at nowhere.example.org.',
      ),
      findsOneWidget,
    );
    expect(opened, isEmpty);

    await tester.enterText(find.byType(TextField), 'learn.example.org');
    await tester.tap(find.text('Continue'));
    await tester.pumpAndSettle();
    expect(opened, [other]);
  });

  testWidgets('an install from before goes on without asking', (tester) async {
    await start(tester, usedBefore: true);

    expect(opened, [builtIn]);
    expect(tab('Home'), findsOneWidget);
  });

  testWidgets('Settings switches between the accounts on the device, and '
      'removes one not in use', (tester) async {
    store = MemoryInstanceStore((current: builtIn, known: [builtIn, other]));
    await start(tester);
    await openSwitcher(tester);
    expect(find.text('learn.halkyon.eu'), findsWidgets);
    await tester.tap(find.text('learn.example.org'));
    await tester.pumpAndSettle();
    expect(opened, [builtIn, other]);
    expect(tab('Home'), findsOneWidget, reason: 'a new app, on Home');

    await openSwitcher(tester);
    await tester.tap(find.byTooltip('Remove account'));
    await tester.pumpAndSettle();
    await tester.tap(find.widgetWithText(FilledButton, 'Remove'));
    await tester.pumpAndSettle();

    expect(forgotten, [builtIn]);
    expect(store.kept?.known, [other]);
  });
}