// test/metadata_stability_test.dart
import 'package:flutter_test/flutter_test.dart';
import 'package:qingting_player/metadata/metadata_model.dart';
import 'package:qingting_player/metadata/metadata_stability.dart';

void main() {
  CandidateMetadata candidate({double confidence = 0.8}) => CandidateMetadata(
        metadata: const NormalizedMetadata(title: '夜曲', artist: '周杰伦'),
        confidence: confidence,
      );

  group('MetadataStability', () {
    test('首次见到 → pending，次数 1', () {
      final d = MetadataStability.decide(
        previous: null,
        candidate: candidate(),
        title: '夜曲',
        artist: '周杰伦',
      );
      expect(d.status, 'pending');
      expect(d.reason, 'first_seen');
      expect(d.validationCount, 1);
    });

    test('第二次结果一致且置信度达标 → verified', () {
      final d = MetadataStability.decide(
        previous: {
          'title': '夜曲',
          'artist': '周杰伦',
          'confidence': 0.8,
          'validation_count': 1,
        },
        candidate: candidate(),
        title: '夜曲',
        artist: '周杰伦',
      );
      expect(d.status, 'verified');
      expect(d.reason, 'stable');
      expect(d.validationCount, 2);
    });

    test('标题或艺术家冲突 → 次数重置为 1，保持 pending', () {
      final d = MetadataStability.decide(
        previous: {
          'title': '夜曲',
          'artist': '周杰伦',
          'confidence': 0.9,
          'validation_count': 5,
        },
        candidate: candidate(),
        title: '完全不同的歌',
        artist: '别的歌手',
      );
      expect(d.status, 'pending');
      expect(d.reason, 'conflict');
      expect(d.validationCount, 1);
    });

    test('置信度不足 → pending，但次数继续累计', () {
      final d = MetadataStability.decide(
        previous: {
          'title': '夜曲',
          'artist': '周杰伦',
          'confidence': 0.4,
          'validation_count': 3,
        },
        candidate: candidate(confidence: 0.5),
        title: '夜曲',
        artist: '周杰伦',
      );
      expect(d.status, 'pending');
      expect(d.reason, 'low_confidence');
      expect(d.validationCount, 4);
    });

    test('一致但只验证过一次 → pending', () {
      final d = MetadataStability.decide(
        previous: {
          'title': '夜曲',
          'artist': '周杰伦',
          'confidence': 0.8,
          'validation_count': 0,
        },
        candidate: candidate(),
        title: '夜曲',
        artist: '周杰伦',
      );
      expect(d.status, 'pending');
      expect(d.reason, 'need_second_validation');
      expect(d.validationCount, 1);
    });

    test('字段缺失不算冲突（旧记录没有艺术家）', () {
      final d = MetadataStability.decide(
        previous: {
          'title': '夜曲',
          'artist': '',
          'confidence': 0.7,
          'validation_count': 1,
        },
        candidate: candidate(),
        title: '夜曲',
        artist: '周杰伦',
      );
      expect(d.status, 'verified');
      expect(d.validationCount, 2);
    });

    test('大小写与首尾空格不影响一致性判断', () {
      final d = MetadataStability.decide(
        previous: {
          'title': ' Night Song ',
          'artist': 'JAY',
          'confidence': 0.8,
          'validation_count': 1,
        },
        candidate: candidate(),
        title: 'night song',
        artist: 'jay',
      );
      expect(d.status, 'verified');
    });
  });
}