import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:hepan_everyday/widgets/directional_week_transition.dart';

Widget _week(int week, {bool reduceMotion = false, VoidCallback? onTap}) =>
    MaterialApp(
      home: MediaQuery(
        data: MediaQueryData(disableAnimations: reduceMotion),
        child: Scaffold(
          body: DirectionalWeekTransition(
            week: week,
            child: SizedBox(
              width: 320,
              height: 180,
              child: Center(
                child: Semantics(
                  label: 'week-$week-course',
                  button: true,
                  excludeSemantics: true,
                  child: TextButton(
                    onPressed: onTap ?? () {},
                    child: Text('Week $week'),
                  ),
                ),
              ),
            ),
          ),
        ),
      ),
    );

FractionalTranslation _translation(WidgetTester tester, String layer) =>
    tester.widget(find.byKey(Key('week-transition-$layer')));

Finder get _layers => find.descendant(
  of: find.byType(DirectionalWeekTransition),
  matching: find.byType(FractionalTranslation),
);

void main() {
  testWidgets(
    'next and previous weeks move in opposite directions then settle',
    (tester) async {
      await tester.pumpWidget(_week(1));
      await tester.pumpWidget(_week(2));
      await tester.pump(const Duration(milliseconds: 100));
      expect(find.text('Week 1'), findsOneWidget);
      expect(find.text('Week 2'), findsOneWidget);
      expect(_translation(tester, 'incoming').translation.dx, greaterThan(0));
      expect(_translation(tester, 'outgoing').translation.dx, lessThan(0));
      final fade = tester.widget<Opacity>(
        find.descendant(
          of: find.byKey(const Key('week-transition-incoming')),
          matching: find.byType(Opacity),
        ),
      );
      expect(fade.opacity, greaterThan(0));
      expect(fade.opacity, lessThan(1));
      await tester.pumpAndSettle();
      expect(find.text('Week 1'), findsNothing);
      expect(_translation(tester, 'incoming').translation, Offset.zero);

      await tester.pumpWidget(_week(1));
      await tester.pump(const Duration(milliseconds: 100));
      expect(_translation(tester, 'incoming').translation.dx, lessThan(0));
      expect(_translation(tester, 'outgoing').translation.dx, greaterThan(0));
      await tester.pumpAndSettle();
      expect(find.text('Week 2'), findsNothing);
      expect(_translation(tester, 'incoming').translation, Offset.zero);
    },
  );

  testWidgets('outgoing courses cannot receive taps or duplicate semantics', (
    tester,
  ) async {
    final semantics = tester.ensureSemantics();
    try {
      var oldTaps = 0;
      await tester.pumpWidget(_week(1, onTap: () => oldTaps++));
      await tester.pumpWidget(_week(2));
      await tester.pump(const Duration(milliseconds: 100));
      expect(find.bySemanticsLabel('week-1-course'), findsNothing);
      expect(find.bySemanticsLabel('week-2-course'), findsOneWidget);
      final oldPointer = tester.widget<IgnorePointer>(
        find
            .ancestor(
              of: find.text('Week 1'),
              matching: find.byType(IgnorePointer),
            )
            .first,
      );
      expect(oldPointer.ignoring, isTrue);
      await tester.tap(find.text('Week 1'), warnIfMissed: false);
      expect(oldTaps, 0);
      await tester.pumpAndSettle();
    } finally {
      semantics.dispose();
    }
  });

  testWidgets(
    'rapid requests keep the running tween and coalesce latest week',
    (tester) async {
      await tester.pumpWidget(_week(1));
      await tester.pumpWidget(_week(2));
      await tester.pump(const Duration(milliseconds: 60));
      final before = _translation(tester, 'incoming').translation;
      await tester.pumpWidget(_week(3));
      expect(_translation(tester, 'incoming').translation, before);
      await tester.pumpWidget(_week(4));
      expect(_translation(tester, 'incoming').translation, before);
      expect(_layers, findsNWidgets(2));
      expect(find.text('Week 3'), findsNothing);
      await tester.pumpAndSettle();
      expect(find.text('Week 4'), findsOneWidget);
      expect(find.text('Week 1'), findsNothing);
      expect(find.text('Week 2'), findsNothing);
      expect(_layers, findsOneWidget);
      expect(_translation(tester, 'incoming').translation, Offset.zero);
      expect(tester.takeException(), isNull);
    },
  );

  testWidgets('rapid reversal returns to latest week without stale layers', (
    tester,
  ) async {
    await tester.pumpWidget(_week(1));
    await tester.pumpWidget(_week(2));
    await tester.pump(const Duration(milliseconds: 70));
    await tester.pumpWidget(_week(3));
    await tester.pumpWidget(_week(1));
    await tester.pump(const Duration(milliseconds: 210));
    await tester.pump(const Duration(milliseconds: 100));
    expect(_translation(tester, 'incoming').translation.dx, lessThan(0));
    await tester.pumpAndSettle();
    expect(find.text('Week 1'), findsOneWidget);
    expect(find.text('Week 2'), findsNothing);
    expect(find.text('Week 3'), findsNothing);
    expect(_layers, findsOneWidget);
  });

  testWidgets('reduced motion snaps and clears an in-flight transition', (
    tester,
  ) async {
    await tester.pumpWidget(_week(1));
    await tester.pumpWidget(_week(2));
    await tester.pump(const Duration(milliseconds: 70));
    await tester.pumpWidget(_week(3, reduceMotion: true));
    expect(find.text('Week 1'), findsNothing);
    expect(find.text('Week 2'), findsNothing);
    expect(find.text('Week 3'), findsOneWidget);
    expect(_translation(tester, 'incoming').translation, Offset.zero);
    expect(find.byKey(const Key('week-transition-outgoing')), findsNothing);
    await tester.pumpWidget(_week(1, reduceMotion: true));
    expect(find.text('Week 1'), findsOneWidget);
    expect(find.text('Week 3'), findsNothing);
    expect(tester.hasRunningAnimations, isFalse);
  });
}