/// ============================================================
/// 题目数据适配层
///
/// 集中处理 QuestionModel 与 UI 组件（RichTextContent / Upload）
/// 之间的数据转换，对标 Vue classExercisesPage.vue 内的
/// stemRenderData / mergedAudios / mergedVideos /
/// getImageAnswerList / getSafeImageAnswerList。
/// ============================================================
library;

import 'dart:convert';

import 'package:new_learn/core/components/upload.dart';
import 'package:new_learn/core/utils/question/extract_media_from_stem.dart';
import 'package:new_learn/core/utils/question/question_parser.dart';

import 'question_model.dart';

/// 题干渲染数据（已格式化 + 已抽取并合并媒体）
class StemRenderData {
  const StemRenderData({
    required this.content,
    this.audios = const [],
    this.videos = const [],
  });

  final String content;
  final List<Map<String, dynamic>> audios;
  final List<Map<String, dynamic>> videos;
}

class QuestionDataAdapter {
  QuestionDataAdapter._();

  /// 等价 Vue 页内 stemRenderData + mergedAudios + mergedVideos
  static StemRenderData buildStemMedia(QuestionModel q, int activeSubIndex) {
    var stem = q.stem.isEmpty ? '暂无题干' : q.stem;
    final hasChilds = q.childs.isNotEmpty;
    final hasBkTags = q.bkTagMetaList.isNotEmpty;

    if (hasChilds || hasBkTags) {
      final disableHighlight = !hasChilds && q.bkTagMetaList.length == 1;
      final subQuestions =
          q.subQuestions.isNotEmpty ? q.subQuestions.map((e) => e.m).toList() : q.childs.map((e) => e.m).toList();
      // 图片作答（1）不做填空锚点格式化
      if (q.isFillblankItemUpload != 1) {
        stem = formatCompoundStem(
          stem,
          activeSubIndex,
          disableHighlight: disableHighlight,
          subQuestions: subQuestions,
        );
      }
      // 数学学科：数字占位符转圈号
      if ('${q.baseSubjectId}' == '2') {
        stem = convertBlankToCircled(stem);
      }
    }

    final media = extractMediaFromStem(stem);

    // 合并题干内嵌媒体与 q.audios/q.videos（按 url 去重，保持 JS 顺序）
    final audios = <Map<String, dynamic>>[];
    for (final item in [...media.audios, ...q.audios]) {
      final url = '${item['audioUrl'] ?? item['url'] ?? ''}';
      if (url.isEmpty) continue;
      if (audios.any((it) => '${it['audioUrl'] ?? it['url']}' == url)) continue;
      audios.add(item);
    }

    final videos = <Map<String, dynamic>>[];
    for (final item in [...media.videos, ...q.videos]) {
      final url = '${item['videoUrl'] ?? item['url'] ?? ''}';
      if (url.isEmpty) continue;
      if (videos.any((it) => '${it['videoUrl'] ?? it['url']}' == url)) continue;
      videos.add(item);
    }

    return StemRenderData(
      content: media.content.isNotEmpty ? media.content : (q.stem.isNotEmpty ? q.stem : '暂无题干'),
      audios: audios,
      videos: videos,
    );
  }

  /// 单空填空题输入框值（对标 singleBlankInputValue）
  static String singleBlankInputValue(QuestionModel q) {
    final direct = q.userAnswer;
    if (direct.isNotEmpty) return direct;
    for (final child in q.childs) {
      final v = '${child.m['userAnswer'] ?? child.m['myAnswer'] ?? ''}';
      if (v.isNotEmpty) return v;
    }
    return '';
  }

  /// 严格解析：getImageAnswerList（外层保证是 JSON 数组字符串）
  static List<Map<String, dynamic>> parseImageAnswerList(dynamic value) {
    if (value == null || '$value'.isEmpty) return const [];
    dynamic data;
    try {
      data = value is String ? jsonDecode(value) : value;
    } catch (_) {
      return const [];
    }
    if (data is! List) return const [];
    return data.whereType<Map>().map((raw) {
      final item = Map<String, dynamic>.from(raw);
      item['url'] = item['Url'] ?? item['url'];
      item['thumbnailUrl'] = item['ThumbnailUrl'] ?? item['thumbnailUrl'];
      return item;
    }).toList();
  }

  /// 安全解析：getSafeImageAnswerList（兜底解析 userAnswer / notes）
  static List<Map<String, dynamic>> safeImageAnswerList(dynamic value) {
    if (value == null || '$value'.isEmpty) return const [];
    dynamic list;
    try {
      list = value is String ? jsonDecode(value) : value;
    } catch (_) {
      return const [];
    }
    if (list is! List) return const [];
    return list
        .whereType<Map>()
        .map((raw) {
          final item = Map<String, dynamic>.from(raw);
          final url = '${item['url'] ?? item['Url'] ?? ''}';
          final thumbnailUrl =
              '${item['thumbnailUrl'] ?? item['ThumbnailUrl'] ?? url}';
          return {...item, 'url': url, 'thumbnailUrl': thumbnailUrl};
        })
        .where((item) => '${item['url']}'.isNotEmpty)
        .toList();
  }

  /// 后端图片数据 → Upload 组件入参
  static List<UploadItem> toUploadItems(List<Map<String, dynamic>> images) {
    return images
        .where((item) => '${item['url']}'.isNotEmpty)
        .map((item) => UploadItem(
              id: item['id'],
              url: '${item['url']}',
              thumbnailUrl: '${item['thumbnailUrl'] ?? item['url']}',
            ))
        .toList();
  }

  /// Upload 组件当前列表 → 提交用 answerImgs
  /// （同时带 url/Url、thumbnailUrl/ThumbnailUrl 兼容后端）
  static List<Map<String, dynamic>> uploadItemsToAnswerImgs(
    List<UploadItem> items,
  ) {
    return items
        .where((e) => e.url.isNotEmpty)
        .map((e) => {
              'url': e.url,
              'Url': e.url,
              'thumbnailUrl': e.thumbnailUrl ?? e.url,
              'ThumbnailUrl': e.thumbnailUrl ?? e.url,
            })
        .toList();
  }

  /// Upload 组件当前列表 → 写回 userAnswer 的 JSON 字符串
  /// （对标 Vue handleUploadChange: JSON.stringify(e)）
  static String uploadItemsToJson(List<UploadItem> items) {
    return jsonEncode(uploadItemsToAnswerImgs(items));
  }
}