import 'package:test/test.dart';
import 'package:tdd_katas/mars_rover.dart';

void main() {
  group('Mars Rover:', () {
    test('rover reports initial position and direction', () {
      final rover = Rover(x: 0, y: 0, direction: 'N');
      
      expect(rover.x, equals(0));
      expect(rover.y, equals(0));
      expect(rover.direction, equals('N'));
    });

    group('Turning Left:', () {
      test('from North faces West', () {
        final rover = Rover(x: 0, y: 0, direction: 'N');
        rover.turnLeft();
        expect(rover.direction, equals('W'));
      });

      test('from West faces South', () {
        final rover = Rover(x: 0, y: 0, direction: 'W');
        rover.turnLeft();
        expect(rover.direction, equals('S'));
      });

      test('from South faces East', () {
        final rover = Rover(x: 0, y: 0, direction: 'S');
        rover.turnLeft();
        expect(rover.direction, equals('E'));
      });

      test('from East faces North', () {
        final rover = Rover(x: 0, y: 0, direction: 'E');
        rover.turnLeft();
        expect(rover.direction, equals('N'));
      });
    });

    group('Turning Right:', () {
      test('from North faces East', () {
        final rover = Rover(x: 0, y: 0, direction: 'N');
        rover.turnRight();
        expect(rover.direction, equals('E'));
      });

      test('from East faces South', () {
        final rover = Rover(x: 0, y: 0, direction: 'E');
        rover.turnRight();
        expect(rover.direction, equals('S'));
      });

      test('from South faces West', () {
        final rover = Rover(x: 0, y: 0, direction: 'S');
        rover.turnRight();
        expect(rover.direction, equals('W'));
      });

      test('from West faces North', () {
        final rover = Rover(x: 0, y: 0, direction: 'W');
        rover.turnRight();
        expect(rover.direction, equals('N'));
      });
    });

    group('Moving Forward:', () {
      test('facing North increases Y', () {
        final rover = Rover(x: 0, y: 0, direction: 'N');
        rover.moveForward();
        expect(rover.x, equals(0));
        expect(rover.y, equals(1));
      });

      test('facing East increases X', () {
        final rover = Rover(x: 0, y: 0, direction: 'E');
        rover.moveForward();
        expect(rover.x, equals(1));
        expect(rover.y, equals(0));
      });

      test('facing South decreases Y', () {
        final rover = Rover(x: 0, y: 5, direction: 'S');
        rover.moveForward();
        expect(rover.x, equals(0));
        expect(rover.y, equals(4));
      });

      test('facing West decreases X', () {
        final rover = Rover(x: 5, y: 0, direction: 'W');
        rover.moveForward();
        expect(rover.x, equals(4));
        expect(rover.y, equals(0));
      });
    });
  });
}