import 'package:flutter_test/flutter_test.dart';
import 'package:hvbt_dash/core/protocol/dtc_map.dart';

void main() {
  group('S300 DTC map', () {
    test('contains expected number of entries', () {
      expect(s300DtcMap.length, equals(32)); // 4 bytes × 8 bits
    });

    // Expected codes come from the S300 "DTC map" in hvbt_protocol.pdf.
    test('ERR00 bit0 = P0130 (O2A)', () {
      expect(s300DtcMap['ERR00_bit0'], startsWith('P0130 — '));
    });

    test('ERR01 bit5 = P0505 (IAC)', () {
      expect(s300DtcMap['ERR01_bit5'], startsWith('P0505 — '));
    });

    test('bench codes: ERR01.6 = P0350, ERR02.3 = P1298, ERR02.4 = P2649', () {
      expect(s300DtcMap['ERR01_bit6'], startsWith('P0350 — '));
      expect(s300DtcMap['ERR02_bit3'], startsWith('P1298 — '));
      expect(s300DtcMap['ERR02_bit4'], startsWith('P2649 — '));
    });

    test('undocumented bits show the raw ERR position', () {
      expect(s300DtcMap['ERR03_bit7'], startsWith('ERR03.7 — '));
    });

    test('every entry has a code and a description', () {
      for (final v in [...s300DtcMap.values, ...kproDtcMap.values]) {
        expect(v.split(' — ').length, equals(2), reason: v);
      }
    });
  });

  group('KPro DTC map', () {
    test('contains entries for 18 bytes (ERR00..ERR17)', () {
      // Every ERR byte has 8 bits = 144 entries total
      expect(kproDtcMap.length, equals(144));
    });

    // Expected codes come from the KPro "DTC map" in hvbt_protocol.pdf.
    test('ERR00 bit1 = P1607, ERR05 bit0 = P1259, ERR11 bit6 = P0304', () {
      expect(kproDtcMap['ERR00_bit1'], startsWith('P1607 — '));
      expect(kproDtcMap['ERR05_bit0'], startsWith('P1259 — '));
      expect(kproDtcMap['ERR11_bit6'], startsWith('P0304 — '));
    });

    test('ERR17 entries present', () {
      expect(kproDtcMap.containsKey('ERR17_bit0'), isTrue);
      expect(kproDtcMap.containsKey('ERR17_bit7'), isTrue);
    });
  });

  group('decodeDtcs helper', () {
    test('returns empty list when no errors', () {
      final result = decodeDtcs([0, 0, 0, 0], s300DtcMap);
      expect(result, isEmpty);
    });

    test('decodes ERR00 bit0 = P0130', () {
      final result = decodeDtcs([0x01, 0, 0, 0], s300DtcMap);
      expect(result, contains(s300DtcMap['ERR00_bit0']));
    });

    test('decodes multiple bits in one byte', () {
      // ERR00 bits 0 and 1
      final result = decodeDtcs([0x03, 0, 0, 0], s300DtcMap);
      expect(result.length, equals(2));
    });

    test('decodes bits across multiple bytes', () {
      // ERR00 bit0 + ERR01 bit0
      final result = decodeDtcs([0x01, 0x01, 0, 0], s300DtcMap);
      expect(result.length, equals(2));
    });

    test('skips bits not in map gracefully', () {
      // Use a small dtcMap with only one entry, but set all bits
      final result = decodeDtcs([0xFF, 0, 0, 0], {'ERR00_bit0': 'P0130 — test'});
      // Only the one mapped bit should appear
      expect(result.length, equals(1));
    });
  });
}