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

void main() {
  testWidgets('displays 0 on start', (tester) async {
    await tester.pumpWidget(const KalkulatorApp());
    // '0' appears on both the display and the '0' button
    expect(find.text('0'), findsWidgets);
  });

  testWidgets('tapping digit updates display', (tester) async {
    await tester.pumpWidget(const KalkulatorApp());
    await tester.tap(find.text('5'));
    await tester.pump();
    expect(find.text('5'), findsWidgets);
  });

  testWidgets('simple addition 3 + 2 = 5', (tester) async {
    await tester.pumpWidget(const KalkulatorApp());
    await tester.tap(find.text('3'));
    await tester.pump();
    await tester.tap(find.text('+'));
    await tester.pump();
    await tester.tap(find.text('2'));
    await tester.pump();
    await tester.tap(find.text('='));
    await tester.pump();
    expect(find.text('5'), findsWidgets);
  });

  testWidgets('clear resets display to 0', (tester) async {
    await tester.pumpWidget(const KalkulatorApp());
    await tester.tap(find.text('7'));
    await tester.pump();
    await tester.tap(find.text('C'));
    await tester.pump();
    expect(find.text('0'), findsWidgets);
  });

  testWidgets('all buttons are rendered', (tester) async {
    await tester.pumpWidget(const KalkulatorApp());
    for (final label in ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']) {
      expect(find.text(label), findsWidgets);
    }
    for (final label in ['+', '-', '*', '/', '=', 'C', '.', '%', '+/-']) {
      expect(find.text(label), findsOneWidget);
    }
  });
}