import 'package:flutter_test/flutter_test.dart';
import 'package:motorcycle_dash/services/routes/valhalla_polyline_decoder.dart';

void main() {
  group('ValhallaPolylineDecoder', () {
    test('handles empty string', () {
      final points = ValhallaPolylineDecoder.decode('');
      expect(points, isEmpty);
    });

    test('decodes single point with precision 6', () {
      // Deterministic fixture for (37.774900, -122.419400)
      final points = ValhallaPolylineDecoder.decode('gbr`gAnk{nhF');
      expect(points.length, 1);
      expect(points[0].latitude, closeTo(37.7749, 1e-5));
      expect(points[0].longitude, closeTo(-122.4194, 1e-5));
    });

    test('decodes multiple points with positive deltas (SF to Oakland)', () {
      // SF (37.774900, -122.419400) -> Oakland (37.804400, -122.271200)
      final points = ValhallaPolylineDecoder.decode('gbr`gAnk{nhFwrx@om`H');
      expect(points.length, 2);
      expect(points[0].latitude, closeTo(37.7749, 1e-5));
      expect(points[0].longitude, closeTo(-122.4194, 1e-5));
      expect(points[1].latitude, closeTo(37.8044, 1e-5));
      expect(points[1].longitude, closeTo(-122.2712, 1e-5));
    });

    test('decodes multiple points with negative lat delta (SF to San Jose)', () {
      // SF (37.774900, -122.419400) -> San Jose (37.338200, -121.886300)
      final points = ValhallaPolylineDecoder.decode('gbr`gAnk{nhFv|sYwep_@');
      expect(points.length, 2);
      expect(points[0].latitude, closeTo(37.7749, 1e-5));
      expect(points[0].longitude, closeTo(-122.4194, 1e-5));
      expect(points[1].latitude, closeTo(37.3382, 1e-5));
      expect(points[1].longitude, closeTo(-121.8863, 1e-5));
    });

    test('throws FormatException on truncated polyline', () {
      expect(
        () => ValhallaPolylineDecoder.decode('gbr`gA'),
        throwsA(isA<FormatException>()),
      );
    });

    test('throws FormatException on invalid characters (ascii < 63)', () {
      expect(
        () => ValhallaPolylineDecoder.decode('gbr\x00gAnk'),
        throwsA(isA<FormatException>()),
      );
    });

    test('throws FormatException when coordinates exceed geographic bounds', () {
      // Encoded value that unpacks to latitude > 90
      // 95.0 * 1e6 = 95000000
      expect(
        () => ValhallaPolylineDecoder.decode('____~_~_~_~_~_'),
        throwsA(isA<FormatException>()),
      );
    });
  });
}