dmc/app/test/widgets/swipe_value_input_test.dart

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

import 'package:dmc_app/ui/widgets/swipe_value_input.dart';

void main() {
  Widget wrap({
    required double value,
    required double initialValue,
    required void Function(double) onChanged,
    double min = 0,
    double max = 200,
    double stepBig = 10,
    double stepSmall = 1,
    int decimals = 0,
  }) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: SwipeValueInput(
            label: 'Test',
            value: value,
            initialValue: initialValue,
            min: min,
            max: max,
            stepBig: stepBig,
            stepSmall: stepSmall,
            decimals: decimals,
            unit: 'm',
            onChanged: onChanged,
          ),
        ),
      ),
    );
  }

  testWidgets('vertikales Ziehen aendert den Wert in grossen Schritten (stepBig)',
      (tester) async {
    final changes = <double>[];
    await tester.pumpWidget(wrap(value: 50, initialValue: 50, onChanged: changes.add));

    // 3 Schritte a 14px nach oben -> +3*stepBig(10) = +30.
    await tester.drag(find.byType(SwipeValueInput), const Offset(0, -42));
    await tester.pump();

    expect(changes, isNotEmpty);
    expect(changes.last, 80);
  });

  testWidgets('horizontales Ziehen aendert den Wert in kleinen Schritten (stepSmall)',
      (tester) async {
    final changes = <double>[];
    await tester.pumpWidget(wrap(value: 50, initialValue: 50, onChanged: changes.add));

    // 3 Schritte a 14px nach rechts -> +3*stepSmall(1) = +3.
    await tester.drag(find.byType(SwipeValueInput), const Offset(42, 0));
    await tester.pump();

    expect(changes, isNotEmpty);
    expect(changes.last, 53);
  });

  testWidgets('nach links/unten ziehen verringert den Wert', (tester) async {
    final changes = <double>[];
    await tester.pumpWidget(wrap(value: 50, initialValue: 50, onChanged: changes.add));

    await tester.drag(find.byType(SwipeValueInput), const Offset(0, 42));
    await tester.pump();

    expect(changes.last, 20);
  });

  testWidgets('klemmt auf max, wenn die grosse Schrittweite darueber hinausschiesst',
      (tester) async {
    final changes = <double>[];
    await tester.pumpWidget(wrap(value: 190, initialValue: 190, onChanged: changes.add));

    await tester.drag(find.byType(SwipeValueInput), const Offset(0, -140));
    await tester.pump();

    expect(changes.last, 200);
  });

  testWidgets('rundet auf die konfigurierte Nachkommastellenzahl', (tester) async {
    final changes = <double>[];
    await tester.pumpWidget(wrap(
      value: 1.0,
      initialValue: 1.0,
      stepSmall: 0.5,
      decimals: 1,
      onChanged: changes.add,
    ));

    await tester.drag(find.byType(SwipeValueInput), const Offset(14, 0));
    await tester.pump();

    expect(changes.last, 1.5);
  });

  testWidgets(
      'aendert den Wert auch innerhalb einer scrollbaren Liste (Regression: '
      'GestureDetector.onPan* verlor frueher gegen die Scroll-Geste der Liste)',
      (tester) async {
    final changes = <double>[];
    await tester.pumpWidget(MaterialApp(
      home: Scaffold(
        body: ListView(
          children: [
            const SizedBox(height: 400),
            SwipeValueInput(
              label: 'Test',
              value: 50,
              initialValue: 50,
              min: 0,
              max: 200,
              stepBig: 10,
              stepSmall: 1,
              unit: 'm',
              onChanged: changes.add,
            ),
            const SizedBox(height: 400),
          ],
        ),
      ),
    ));

    await tester.drag(find.byType(SwipeValueInput), const Offset(0, -42));
    await tester.pump();

    expect(changes, isNotEmpty);
    expect(changes.last, 80);
  });

  testWidgets('zeigt den "modified"-Punkt nur, wenn der Wert vom Ausgangswert abweicht',
      (tester) async {
    await tester.pumpWidget(wrap(value: 50, initialValue: 50, onChanged: (_) {}));
    var opacity = tester.widget<AnimatedOpacity>(find.byType(AnimatedOpacity));
    expect(opacity.opacity, 0);

    await tester.pumpWidget(wrap(value: 60, initialValue: 50, onChanged: (_) {}));
    opacity = tester.widget<AnimatedOpacity>(find.byType(AnimatedOpacity));
    expect(opacity.opacity, 1);
  });
}