import 'package:flutter_test/flutter_test.dart';
import 'package:kalkulator/calculator_logic.dart';

void main() {
  late CalculatorLogic calc;

  setUp(() {
    calc = CalculatorLogic();
  });

  group('inputDigit', () {
    test('starts with 0', () {
      expect(calc.display, '0');
    });

    test('replaces initial 0 with digit', () {
      calc.inputDigit('5');
      expect(calc.display, '5');
    });

    test('appends digits', () {
      calc.inputDigit('1');
      calc.inputDigit('2');
      calc.inputDigit('3');
      expect(calc.display, '123');
    });
  });

  group('inputDecimal', () {
    test('adds decimal point', () {
      calc.inputDigit('3');
      calc.inputDecimal();
      expect(calc.display, '3.');
    });

    test('ignores second decimal point', () {
      calc.inputDigit('3');
      calc.inputDecimal();
      calc.inputDigit('1');
      calc.inputDecimal();
      expect(calc.display, '3.1');
    });
  });

  group('addition', () {
    test('2 + 3 = 5', () {
      calc.inputDigit('2');
      calc.inputOperator('+');
      calc.inputDigit('3');
      calc.calculate();
      expect(calc.display, '5');
    });
  });

  group('subtraction', () {
    test('9 - 4 = 5', () {
      calc.inputDigit('9');
      calc.inputOperator('-');
      calc.inputDigit('4');
      calc.calculate();
      expect(calc.display, '5');
    });
  });

  group('multiplication', () {
    test('6 * 7 = 42', () {
      calc.inputDigit('6');
      calc.inputOperator('*');
      calc.inputDigit('7');
      calc.calculate();
      expect(calc.display, '42');
    });
  });

  group('division', () {
    test('8 / 2 = 4', () {
      calc.inputDigit('8');
      calc.inputOperator('/');
      calc.inputDigit('2');
      calc.calculate();
      expect(calc.display, '4');
    });

    test('division by zero returns Infinity', () {
      calc.inputDigit('5');
      calc.inputOperator('/');
      calc.inputDigit('0');
      calc.calculate();
      expect(calc.display, 'Infinity');
    });

    test('decimal result: 7 / 2 = 3.5', () {
      calc.inputDigit('7');
      calc.inputOperator('/');
      calc.inputDigit('2');
      calc.calculate();
      expect(calc.display, '3.5');
    });
  });

  group('chained operations', () {
    test('2 + 3 + 4 = 9', () {
      calc.inputDigit('2');
      calc.inputOperator('+');
      calc.inputDigit('3');
      calc.inputOperator('+');
      expect(calc.display, '5');
      calc.inputDigit('4');
      calc.calculate();
      expect(calc.display, '9');
    });
  });

  group('clear', () {
    test('resets to 0', () {
      calc.inputDigit('5');
      calc.inputOperator('+');
      calc.inputDigit('3');
      calc.clear();
      expect(calc.display, '0');
    });
  });

  group('toggleSign', () {
    test('positive to negative', () {
      calc.inputDigit('7');
      calc.toggleSign();
      expect(calc.display, '-7');
    });

    test('negative to positive', () {
      calc.inputDigit('7');
      calc.toggleSign();
      calc.toggleSign();
      expect(calc.display, '7');
    });
  });

  group('percent', () {
    test('50 percent = 0.5', () {
      calc.inputDigit('5');
      calc.inputDigit('0');
      calc.percent();
      expect(calc.display, '0.5');
    });
  });
}