/// 题目数据模型

class Problem {
  final String id;
  final double difficulty;
  final String questionType;
  final String importType;
  final List<String> chapters;
  final List<String> knowledgeCodes;
  final String comment;
  final String source;
  final String createdAt;
  final String updatedAt;
  final String? renderHtml;
  final String bodyPreview;

  Problem({
    required this.id,
    this.difficulty = 0.5,
    this.questionType = '',
    this.importType = '精选题',
    this.chapters = const [],
    this.knowledgeCodes = const [],
    this.comment = '',
    this.source = '',
    this.createdAt = '',
    this.updatedAt = '',
    this.renderHtml,
    this.bodyPreview = '',
  });

  factory Problem.fromJson(Map<String, dynamic> json) {
    return Problem(
      id: json['id'] ?? '',
      difficulty: (json['difficulty'] ?? 0.5).toDouble(),
      questionType: json['question_type'] ?? '',
      importType: json['import_type'] ?? '精选题',
      chapters: List<String>.from(json['chapters'] ?? []),
      knowledgeCodes: List<String>.from(json['knowledge_codes'] ?? []),
      comment: json['comment'] ?? '',
      source: json['source'] ?? '',
      createdAt: json['created_at'] ?? '',
      updatedAt: json['updated_at'] ?? '',
      renderHtml: json['render_html'],
      bodyPreview: json['body_preview'] ?? '',
    );
  }

  String get difficultyLabel {
    if (difficulty >= 0.7) return '易';
    if (difficulty >= 0.4) return '中';
    return '难';
  }

  bool get isAnnotated => knowledgeCodes.isNotEmpty && knowledgeCodes.first.isNotEmpty;
}

/// 搜索命中结果
class SearchResult {
  final String id;
  final String bodySnippet;
  final double difficulty;
  final String questionType;
  final String importType;
  final List<String> chapters;

  SearchResult({
    required this.id,
    this.bodySnippet = '',
    this.difficulty = 0.5,
    this.questionType = '',
    this.importType = '',
    this.chapters = const [],
  });

  factory SearchResult.fromJson(Map<String, dynamic> json) {
    return SearchResult(
      id: json['id'] ?? '',
      bodySnippet: json['body_snippet'] ?? '',
      difficulty: (json['difficulty'] ?? 0.5).toDouble(),
      questionType: json['question_type'] ?? '',
      importType: json['import_type'] ?? '',
      chapters: List<String>.from(json['chapters'] ?? []),
    );
  }
}