/// ============================================================
/// 【ExerciseQuestionView】课后练习单题页
/// （1:1 迁移 Vue pages/conquerPackage/classExercises/classExercisesPage.vue）
///
/// 结构（与 Vue 模板一致）：
///   source → 题型标签 → 题干合并音视频 → 题干（含 #subquestion-N 锚点）
///   → 主体（客观选项 / 填空输入或图片作答 / 主观图片作答）
///   → view 态 childs 解析列表 → 大题解析盒 → 底部笔记 Upload
///   → 末尾 80.h + panelHeight 白色占位
///
/// 交互（与 Vue emit / defineExpose 同名同义）：
///   - onSelectAnswer(payload)            → selectAnswer
///   - onUpdateAnswer(String)             → UpdateAnswer
///   - onNotesChange(items)               → handleNotesChange
///   - onSubQuestionChange(payload)       → subQuestionChange
///   - onStemLinkTap(index)               → 题干锚点点击，由父级驱动复合题面板
///   - `GlobalKey<ExerciseQuestionViewState>` 暴露：
///       UploadLectureNotes() / getImageList(type) /
///       setActiveSubIndex(i) / pauseMedia() / scrollToOffset()
///
/// 说明：
///   - 父级应以 ValueKey(data.id) 挂载，切题整体重建；
///   - 锚点滚动：#subquestion-N 点击后 onTapUrl 返回 false，交由
///     flutter_widget_from_html 内置 AnchorRegistry 滚动（等价 Vue
///     emitScrollToTop → outer scroll-view 定位）；面板 tab 切换等
///     外部回灌走 scrollToAnchor（编程式标记位，不再回调父级）；
///   - isActive/isAdjacent 变 false 暂停全部音视频（递归 visitChildElements）。
/// ============================================================
library;

import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:flutter_widget_from_html_core/flutter_widget_from_html_core.dart';
import 'package:new_learn/core/components/audio_player_card.dart';
import 'package:new_learn/core/components/media_pause_scope.dart';
import 'package:new_learn/core/components/rich_text_content.dart';
import 'package:new_learn/core/components/upload.dart';
import 'package:new_learn/core/components/video_player_view.dart';
import 'package:new_learn/core/utils/img_url.dart';
import 'package:new_learn/core/utils/question/question_parser.dart';
import 'package:new_learn/core/utils/question/tag_color.dart';

import 'models/question_data_adapter.dart';
import 'models/question_model.dart';
import 'widgets/answer_view.dart';
import 'widgets/exercise_styles.dart';
import 'widgets/obj_options.dart';

/// 对应 Vue props.typeMode
enum ExerciseQuestionMode { edit, view }

/// 对应 emit('subQuestionChange', {subIndex, sort})
class SubQuestionChangePayload {
  const SubQuestionChangePayload({required this.subIndex, this.sort = 0});

  final int subIndex;
  final dynamic sort;
}

typedef QuestionSelectCallback = void Function(Map<String, dynamic> payload);
typedef QuestionUpdateAnswerCallback = void Function(String value);
typedef QuestionNotesCallback = void Function(List<UploadItem> items);
typedef QuestionSubChangeCallback = void Function(SubQuestionChangePayload payload);
typedef QuestionStemLinkCallback = void Function(int subIndex);

class ExerciseQuestionView extends StatefulWidget {
  const ExerciseQuestionView({
    super.key,
    required this.data,
    this.isActive = false,
    this.isAdjacent = false,
    this.mode = ExerciseQuestionMode.edit,
    this.activeSubIndex = 0,
    required this.panelHeight,
    this.onSelectAnswer,
    this.onUpdateAnswer,
    this.onNotesChange,
    this.onSubQuestionChange,
    this.onStemLinkTap,
  });

  /// 题目数据（与 questionsList 元素同一 Map 引用）
  final QuestionModel data;

  final bool isActive;
  final bool isAdjacent;
  final ExerciseQuestionMode mode;

  /// 当前激活子题下标（外部回灌）
  final int activeSubIndex;

  /// 复合题浮层当前高度（逻辑像素），用于末尾占位。
  /// 用 ValueListenable 接收：拖拽面板时只重建占位盒，不整页重建。
  final ValueListenable<double> panelHeight;

  final QuestionSelectCallback? onSelectAnswer;
  final QuestionUpdateAnswerCallback? onUpdateAnswer;
  final QuestionNotesCallback? onNotesChange;
  final QuestionSubChangeCallback? onSubQuestionChange;
  final QuestionStemLinkCallback? onStemLinkTap;

  @override
  ExerciseQuestionViewState createState() => ExerciseQuestionViewState();
}

class ExerciseQuestionViewState extends State<ExerciseQuestionView> {
  final ScrollController _scrollController = ScrollController();

  /// 本题媒体暂停注册表：子树内播放器自动注册，切页时直接暂停，
  /// 不再运行时递归 visitChildElements（避免 element 树更新期断言）
  final MediaPauseRegistry _mediaRegistry = MediaPauseRegistry();

  /// 题干 HtmlWidget（锚点滚动用）
  final GlobalKey<HtmlWidgetState> _stemHtmlKey = GlobalKey<HtmlWidgetState>();

  /// 图片作答 Upload（uploadAnswerRef）
  final GlobalKey<UploadState> _answerUploadKey = GlobalKey<UploadState>();

  /// 笔记 Upload（uploadRef）
  final GlobalKey<UploadState> _notesKey = GlobalKey<UploadState>();

  late int _activeSubIndex = widget.activeSubIndex;

  /// 图片作答缓存（惰性初始化，保持引用稳定，避免 Upload 被重置）
  List<UploadItem>? _answerItems;

  /// 笔记图片缓存
  List<UploadItem>? _notesItems;

  TextEditingController? _blankController;

  /// 本次锚点切换是否来自题干点击（点击已由 fwfh 滚动，外部回灌跳过）
  int? _tapDrivenIndex;

  /// 编程式锚点滚动标记（scrollToAnchor 期间不要再驱动面板）
  bool _programmaticAnchor = false;

  bool get _isView => widget.mode == ExerciseQuestionMode.view;
  bool get _isEdit => widget.mode == ExerciseQuestionMode.edit;

  // ===================== 生命周期 =====================

  @override
  void initState() {
    super.initState();
    // 对标 watch(activeSubIndex, immediate: true)：挂载即尝试定位锚点
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted) _scrollToAnchorExternal(widget.activeSubIndex);
    });
  }

  @override
  void didUpdateWidget(covariant ExerciseQuestionView oldWidget) {
    super.didUpdateWidget(oldWidget);

    // 正常父级以 ValueKey(data.id) 重建；兜底处理
    if (widget.data.id != oldWidget.data.id) {
      _activeSubIndex = 0;
      _answerItems = null;
      _notesItems = null;
      pauseMedia();
    }

    // 对标 watch(isActive) / watch(isAdjacent)
    if ((widget.isActive != oldWidget.isActive && !widget.isActive) ||
        (widget.isAdjacent != oldWidget.isAdjacent && !widget.isAdjacent)) {
      pauseMedia();
    }

    // 对标 watch(() => props.activeSubIndex)
    if (widget.activeSubIndex != _activeSubIndex &&
        widget.activeSubIndex != oldWidget.activeSubIndex) {
      final ext = widget.activeSubIndex;
      if (ext == _tapDrivenIndex) {
        // 点击触发的回灌，fwfh 已在点击时滚动
        _tapDrivenIndex = null;
      } else {
        WidgetsBinding.instance.addPostFrameCallback((_) {
          if (mounted) _scrollToAnchorExternal(ext);
        });
      }
      setState(() => _activeSubIndex = ext);
    }
  }

  @override
  void dispose() {
    _scrollController.dispose();
    _blankController?.dispose();
    super.dispose();
  }

  // ===================== 对外暴露（对标 defineExpose） =====================

  /// 触发笔记选图（对标 UploadLectureNotes → uploadRef.chooseImage）
  Future<void> uploadLectureNotes() async {
    return _notesKey.currentState?.chooseImage();
  }

  /// 取图片列表（对标 getImageList）
  /// - type == 'uploadAnswerRef'：作答图，兜底 safeImageAnswerList(userAnswer)
  /// - 其它：笔记图，兜底 safeImageAnswerList(notes)
  List<dynamic> getImageList(String type) {
    if (type == 'uploadAnswerRef') {
      final imageList = _answerUploadKey.currentState?.getImageList();
      if (imageList != null && imageList.isNotEmpty) return imageList;
      return QuestionDataAdapter.safeImageAnswerList(widget.data.userAnswer);
    }
    final imageList = _notesKey.currentState?.getImageList();
    if (imageList != null && imageList.isNotEmpty) return imageList;
    return QuestionDataAdapter.safeImageAnswerList(widget.data.m['notes']);
  }

  /// 对标 setActiveSubIndex：clamp + emit subQuestionChange
  void setActiveSubIndex(int subIndex) {
    final total = widget.data.subQuestions.length;
    final next = total > 0
        ? subIndex.clamp(0, total - 1)
        : 0;
    if (next == _activeSubIndex) return;
    setState(() => _activeSubIndex = next);
    final sort = widget.data.subAt(next)?.sort ?? 0;
    widget.onSubQuestionChange
        ?.call(SubQuestionChangePayload(subIndex: next, sort: sort));
  }

  /// 暂停视图内全部音视频（对标 pauseMedia）。
  /// 直接调注册表：播放器挂载/卸载已自动维护成员，
  /// 无需运行时递归遍历 element 树，build/翻页动画阶段调用同样安全。
  void pauseMedia() {
    _mediaRegistry.pauseAll();
  }

  /// 父级直接驱动滚动（对标 emit scrollToOffset → outer scroll-view）
  void scrollToOffset(double offset) {
    if (!_scrollController.hasClients) return;
    final max = _scrollController.position.maxScrollExtent;
    _scrollController.jumpTo(offset.clamp(0, max));
  }

  // ===================== 锚点滚动 =====================

  /// 题干链接点击：驱动面板 + 交回 fwfh 滚动锚点（return false）
  Future<bool> _onStemTap(String url) async {
    if (url.startsWith('#subquestion-')) {
      final idx = int.tryParse(url.replaceFirst('#subquestion-', ''));
      if (idx != null && idx >= 0) {
        _tapDrivenIndex = idx;
        widget.onStemLinkTap?.call(idx);
        // false：fwfh 继续执行 AnchorRegistry.ensureVisible
        return false;
      }
    }
    // 其余链接一律拦截（RichTextContent 默认行为）
    return true;
  }

  /// 外部回灌（面板 tab / 切题恢复）：只滚动，不再回调 onStemLinkTap
  void _scrollToAnchorExternal(int index, {int retries = 4}) {
    bool done = false;
    void run(int left) async {
      if (!mounted || done) return;
      _programmaticAnchor = true;
      bool ok = false;
      try {
        ok = await _stemHtmlKey.currentState
                ?.scrollToAnchor('subquestion-$index') ??
            false;
      } finally {
        _programmaticAnchor = false;
      }
      if (ok) {
        done = true;
        return;
      }
      if (left > 0 && mounted) {
        Future.delayed(const Duration(milliseconds: 120), () {
          if (mounted) run(left - 1);
        });
      }
    }

    run(retries);
  }

  // ===================== 作答回调 =====================

  /// 对标 selectOption（父级写 current.userAnswer = payload.userAnswer）
  void _selectOption(Map<String, dynamic> payload) {
    if (!_isEdit) return;
    widget.onSelectAnswer?.call(payload);
  }

  /// 对标 onInputBlank：写 data.userAnswer + 第一个 child，emit 纯文本
  void _onInputBlank(String value) {
    if (!_isEdit) return;
    widget.data.userAnswer = value;
    final childs = widget.data.childs;
    if (childs.isNotEmpty) {
      childs.first.userAnswer = value;
    }
    widget.onUpdateAnswer?.call(value);
  }

  /// 对标 handleUploadChange：emit UpdateAnswer(JSON.stringify(e))
  void _onAnswerUploadChanged(List<UploadItem> items) {
    _answerItems = List<UploadItem>.from(items);
    widget.onUpdateAnswer
        ?.call(QuestionDataAdapter.uploadItemsToJson(items));
  }

  /// 对标 handleNotesChange
  void _onNotesChanged(List<UploadItem> items) {
    _notesItems = List<UploadItem>.from(items);
    widget.onNotesChange?.call(items);
  }

  List<UploadItem> get _answerUploadItems {
    return _answerItems ??= QuestionDataAdapter.toUploadItems(
      QuestionDataAdapter.parseImageAnswerList(widget.data.userAnswer),
    );
  }

  List<UploadItem> get _notesUploadItems {
    return _notesItems ??= QuestionDataAdapter.toUploadItems(
      widget.data.notes,
    );
  }

  // ===================== Build =====================

  @override
  Widget build(BuildContext context) {
    // 题干渲染数据（对标 stemRenderData / mergedAudios / mergedVideos）
    final stemMedia =
        QuestionDataAdapter.buildStemMedia(widget.data, _activeSubIndex);

    final children = <Widget>[
      // ---- source ----
      if (widget.data.source.isNotEmpty)
        Padding(
          padding: EdgeInsets.only(bottom: 10.h),
          child: Text(
            widget.data.source,
            style: TextStyle(fontSize: 14.sp, color: ExerciseColors.subtitle),
          ),
        ),

      // ---- 题型标签 ----
      Padding(
        padding: EdgeInsets.only(bottom: 10.h),
        child: _buildTypeLabel(),
      ),

      // ---- 题干合并音视频 ----
      for (final audio in stemMedia.audios)
        Padding(
          padding: EdgeInsets.symmetric(vertical: 10.h),
          child: AudioPlayerCard(
            url: '${audio['audioUrl'] ?? audio['url'] ?? ''}',
          ),
        ),
      for (final video in stemMedia.videos)
        Padding(
          padding: EdgeInsets.symmetric(vertical: 10.h),
          child: VideoPlayerView(
            url: '${video['videoUrl'] ?? video['url'] ?? ''}',
          ),
        ),

      // ---- 题干（line-height 58rpx，margin-b 30rpx）----
      
      Padding(
        padding: EdgeInsets.only(bottom: 15.h),
        child: RichTextContent(
          htmlWidgetKey: _stemHtmlKey,
          html: stemMedia.content,
          textStyle: TextStyle(
            fontSize: 16.sp,
            color: const Color(0xFF333333),
            height: 58 / 32,
          ),
          onTapUrl: (url) async {
            // 编程式滚动期间：锚点链接不拦截（让 fwfh 滚动），也不驱动面板
            if (_programmaticAnchor && url.startsWith('#subquestion-')) {
              return false;
            }
            return _onStemTap(url);
          },
        ),
      ),
    ];

    // ---- 主体（v-if="!data.hasOptionChildrenQuestion"）----
    if (!widget.data.hasOptionChildrenQuestion) {
      _buildBody(children);
    }

    // ---- childs 解析列表（view，且非 hasOptionChildrenQuestion）----
    if (!widget.data.hasOptionChildrenQuestion &&
        widget.data.childs.isNotEmpty &&
        _isView) {
      _buildChildsAnalysis(children);
    }

    // ---- 大题解析盒（仅 view）----
    if (_isView) {
      _appendMainAnalysis(children);
    }

    // ---- 底部笔记 Upload ----
    children.add(Padding(
      padding: EdgeInsets.only(top: isPadDevice(context) ? 40.h : 30.h),
      child: Upload(
        key: _notesKey,
        type: UploadType.questions,
        ids: widget.data.id,
        mode: _isEdit ? UploadMode.edit : UploadMode.view,
        initialImageList: _notesUploadItems,
        onChanged: _onNotesChanged,
      ),
    ));

    return MediaPauseScope(
      registry: _mediaRegistry,
      child: ClipRRect(
        borderRadius: BorderRadius.vertical(top: Radius.circular(14.r)),
        child: ColoredBox(
          color: Colors.white,
          child: SingleChildScrollView(
            controller: _scrollController,
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                // 对标 .classExercises-main（白底、上圆角 28rpx、padding 40rpx 28rpx）
                Container(
                  width: double.infinity,
                  color: Colors.white,
                  padding: EdgeInsets.symmetric(horizontal: 14.w, vertical: 20.h),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: children,
                  ),
                ),
                // 对标末尾占位 calc(160rpx + panelHeight px)。
                // 仅占位盒随面板高度重建，拖拽不触发整页重建。
                ValueListenableBuilder<double>(
                  valueListenable: widget.panelHeight,
                  builder: (_, h, __) => Container(
                    width: double.infinity,
                    height: 80.h + h,
                    color: Colors.white,
                  ),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  /// 题型标签（对标 .classExercises-main-label + getTagColor）
  Widget _buildTypeLabel() {
    final gradient = getTagColor(widget.data.questionTypeName);
    return Container(
      height: 21.h,
      padding: EdgeInsets.symmetric(horizontal: 6.w),
      decoration: BoxDecoration(
        gradient: gradient.gradient,
        borderRadius: BorderRadius.circular(6.r),
      ),
      child: Center(
        widthFactor: 1,
        child: Text(
          widget.data.questionTypeName,
          style: TextStyle(
            fontSize: 12.sp,
            color: Colors.white,
            height: 1,
          ),
        ),
      ),
    );
  }

  // ===================== 主体分支 =====================

  void _buildBody(List<Widget> children) {
    final data = widget.data;

    // 分支 1：客观题（options 非空）
    if (data.options.isNotEmpty) {
      if (_isEdit) {
        children.add(ObjOptions(
          options: data.options,
          questionType: data.questionTypes,
          mode: ObjOptionMode.edit,
          answer: data.userAnswer,
          onChanged: _selectOption,
        ));
      } else {
        children.add(ObjOptions(
          options: data.options,
          questionType: data.questionTypes,
          mode: ObjOptionMode.view,
          answerData: ObjOptionAnswerData(
            correctAnswer: data.correctAnswer,
            myAnswer: data.userAnswer,
          ),
          onChanged: _selectOption,
        ));
        children.add(Padding(
          padding: EdgeInsets.only(bottom: 10.h),
          child: ObjectiveAnswerView(
            answerStatus: data.answerStatus,
            userAnswer: data.userAnswer,
            correctAnswer: data.correctAnswer,
          ),
        ));
      }
      return;
    }

    // 分支 2：填空题
    if (data.questionTypes == 'tiankongti') {
      _buildBlankBody(children);
      return;
    }

    // 分支 3：其他主观题（问答题等，图片作答）
    _buildSubjectiveBody(children);
  }

  /// 填空题主体（对标 v-else-if="questionTypes == 'tiankongti'"）
  void _buildBlankBody(List<Widget> children) {
    final data = widget.data;

    if (_isView) {
      children.add(_buildStatusStrip(data));
    }

    if (data.isFillblankItemUpload == 1) {
      // 图片作答填空题（注意：单题页 maxCount = 10）
      children.add(Padding(
        padding: EdgeInsets.only(top: 10.h),
        child: Upload(
          key: _answerUploadKey,
          title: '上传图片作答',
          maxCount: 10,
          type: UploadType.aiGrading,
          ids: data.id,
          mode: _isEdit ? UploadMode.edit : UploadMode.view,
          initialImageList: _answerUploadItems,
          onChanged: _onAnswerUploadChanged,
        ),
      ));
      if (_isView) {
        _appendWrongReasonAdvice(children);
      }
    } else if (_isEdit) {
      children.add(_buildBlankTextarea());
    }

    if (_isView) {
      if (data.isFillblankItemUpload != 1) {
        children.add(Padding(
          padding: EdgeInsets.only(top: 10.h),
          child: _buildAnswerTitle('你的答案'),
        ));
        children.add(_buildAnswerContent(
          data.effectiveAnswer,
          const Color(0xFF495A7A),
        ));
      }
      if (data.hasOptionChildrenQuestion || data.childs.isEmpty) {
        children.add(_buildAnswerTitle('正确答案'));
        children.add(_buildAnswerContent(
          data.correctAnswer.isNotEmpty ? data.correctAnswer : data.answer,
          ExerciseColors.correct,
        ));
      }
    }
  }

  /// 主观题主体（问答题等）
  void _buildSubjectiveBody(List<Widget> children) {
    final data = widget.data;

    if (_isView) {
      children.add(_buildStatusStrip(data));
    }

    children.add(Padding(
      padding: EdgeInsets.only(top: isPadDevice(context) ? 40.h : 30.h),
      child: Upload(
        key: _answerUploadKey,
        title: '上传图片作答',
        maxCount: 10,
        type: UploadType.aiGrading,
        ids: data.id,
        mode: _isEdit ? UploadMode.edit : UploadMode.view,
        initialImageList: _answerUploadItems,
        onChanged: _onAnswerUploadChanged,
      ),
    ));

    if (_isView) {
      _appendWrongReasonAdvice(children);
      if (data.hasOptionChildrenQuestion || data.childs.isEmpty) {
        children.add(_buildAnswerTitle('正确答案'));
        children.add(_buildAnswerContent(
          data.correctAnswer.isNotEmpty ? data.correctAnswer : data.answer,
          ExerciseColors.correct,
        ));
      }
    }
  }

  /// 错误原因 / 改进建议（仅 view，answerStatus 11/12）
  void _appendWrongReasonAdvice(List<Widget> children) {
    final data = widget.data;
    final status = data.answerStatus;
    if (status != 11 && status != 12) return;

    final reason = data.wrongReason;
    if (reason != null && reason.isNotEmpty) {
      children.add(Padding(
        padding: EdgeInsets.only(top: 10.h),
        child: _buildAnswerTitle('错误原因'),
      ));
      children.add(_buildPlainContent(reason, const Color(0xFF495A7A)));
    }
    final advice = data.wrongAdvice;
    if (advice != null && advice.isNotEmpty) {
      children.add(Padding(
        padding: EdgeInsets.only(top: 10.h),
        child: _buildAnswerTitle('改进建议'),
      ));
      children.add(_buildPlainContent(advice, const Color(0xFF495A7A)));
    }
  }

  /// 填空题输入框（对标 textarea.auto-height + .input-text）
  Widget _buildBlankTextarea() {
    final controller = _blankController ??= TextEditingController(
      text: QuestionDataAdapter.singleBlankInputValue(widget.data),
    );
    return Container(
      width: double.infinity,
      margin: EdgeInsets.only(bottom: 10.h),
      padding: EdgeInsets.symmetric(horizontal: 12.w, vertical: 14.h),
      decoration: BoxDecoration(
        color: ExerciseColors.bg,
        borderRadius: BorderRadius.circular(12.r),
        border: Border.all(color: ExerciseColors.border, width: 1.w),
      ),
      child: TextField(
        controller: controller,
        minLines: 1,
        maxLines: null,
        style: TextStyle(
          fontSize: 16.sp,
          color: const Color(0xFF333333),
        ),
        onChanged: _onInputBlank,
        decoration: InputDecoration(
          isCollapsed: true,
          border: InputBorder.none,
          hintText: '请输入您的答案...',
          hintStyle: TextStyle(
            fontSize: 16.sp,
            color: const Color(0xFF94A5B8),
          ),
        ),
      ),
    );
  }

  // ===================== childs 解析列表 =====================

  void _buildChildsAnalysis(List<Widget> children) {
    final data = widget.data;
    final childs = data.childs;
    for (var i = 0; i < childs.length; i++) {
      final child = childs[i];

      children.add(_buildAnswerTitle(
        '第${i + 1}${data.questionTypes == 'tiankongti' ? '空' : '题'}',
        fontSize: 17.sp,
      ));

      if (child.stem.isNotEmpty) {
        children.add(Padding(
          padding: EdgeInsets.only(bottom: 5.h),
          child: RichTextContent(
            html: child.stem,
            textStyle: TextStyle(
              fontSize: 16.sp,
              color: const Color(0xFF333333),
            ),
          ),
        ));
      }

      children.add(_buildAnswerTitle('正确答案'));
      children.add(_buildAnswerContent(
        child.correctAnswer.isNotEmpty ? child.correctAnswer : child.answer,
        ExerciseColors.correct,
      ));

      final analysis = _analysisText(child);
      final videos = child.videos;
      final analysisVideo = child.answerAnalysisVideo;
      final hasVideo = videos.isNotEmpty &&
          '${videos.first['videoUrl'] ?? videos.first['url'] ?? ''}'
              .isNotEmpty;
      final hasAnalysisVideo =
          '${analysisVideo?['videoUrl'] ?? ''}'.isNotEmpty;

      if (analysis.isNotEmpty || hasVideo || hasAnalysisVideo) {
        final content = <Widget>[
          if (analysis.isNotEmpty) _buildAnalysisBody(analysis),
          if (hasVideo)
            for (final video in videos)
              Padding(
                padding: EdgeInsets.only(top: 10.h),
                child: VideoPlayerView(
                  url: '${video['videoUrl'] ?? video['url'] ?? ''}',
                ),
              ),
          if (hasAnalysisVideo)
            Padding(
              padding: EdgeInsets.only(top: 10.h),
              child: VideoPlayerView(
                url: '${analysisVideo?['videoUrl'] ?? ''}',
              ),
            ),
        ];
        children.add(_buildAnalysisBox(content, minHeight: true));
      }
    }
  }

  // ===================== 大题解析盒 =====================

  void _appendMainAnalysis(List<Widget> children) {
    final data = widget.data;
    final analysis = _analysisText(data);
    final audios = data.audios;
    final videos = data.videos;
    final analysisVideo = data.answerAnalysisVideo;
    final hasVideo = videos.isNotEmpty &&
        '${videos.first['videoUrl'] ?? videos.first['url'] ?? ''}'.isNotEmpty;
    final hasAnalysisVideo =
        '${analysisVideo?['videoUrl'] ?? ''}'.isNotEmpty;

    // 对标 v-if：audios || videos.length>0 || answerAnalysisVideo.videoUrl || 解析
    if (analysis.isEmpty &&
        audios.isEmpty &&
        videos.isEmpty &&
        !hasAnalysisVideo) {
      return;
    }

    final content = <Widget>[
      // 音视频在解析文字之前
      for (final audio in audios)
        Padding(
          padding: EdgeInsets.only(top: 10.h),
          child: AudioPlayerCard(
            url: '${audio['audioUrl'] ?? audio['url'] ?? ''}',
          ),
        ),
      if (hasVideo)
        for (final video in videos)
          Padding(
            padding: EdgeInsets.only(top: 10.h),
            child: VideoPlayerView(
              url: '${video['videoUrl'] ?? video['url'] ?? ''}',
            ),
          ),
      if (hasAnalysisVideo)
        Padding(
          padding: EdgeInsets.only(top: 10.h),
          child: VideoPlayerView(
            url: '${analysisVideo?['videoUrl'] ?? ''}',
          ),
        ),
      if (analysis.isNotEmpty) _buildAnalysisBody(analysis),
    ];

    children.add(_buildAnalysisBox(content, minHeight: true));
  }

  /// 对标 .analysis-body（32rpx / 1.55 / #1D2B47，margin 20rpx 0 24rpx）
  Widget _buildAnalysisBody(String analysis) {
    return Padding(
      padding: EdgeInsets.only(top: 10.h, bottom: 12.h),
      child: RichTextContent(
        html: cleanRichText(analysis),
        textStyle: TextStyle(
          fontSize: 16.sp,
          height: 1.55,
          color: ExerciseColors.title,
        ),
      ),
    );
  }

  /// 对标 .analysis-box（单题页 CSS：margin 66rpx 0 40rpx、min-height 200rpx）
  Widget _buildAnalysisBox(List<Widget> content, {bool minHeight = false}) {
    return Container(
      constraints: minHeight ? BoxConstraints(minHeight: 100.h) : null,
      margin: EdgeInsets.only(top: 33.h, bottom: 20.h),
      decoration: BoxDecoration(
        borderRadius: BorderRadius.circular(12.r),
        // 对标 border-box 渐变 146.26deg
        gradient: const LinearGradient(
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
          colors: [Color(0xFF95F8E7), Color(0xFFB9DDFF), Color(0xFF99DCFE)],
          stops: [0, 0.4952, 1],
        ),
      ),
      padding: EdgeInsets.all(1.5.w),
      child: Container(
        decoration: BoxDecoration(
          borderRadius: BorderRadius.circular(12.r - 1.5.w),
          // 对标 padding-box 渐变 180deg
          gradient: const LinearGradient(
            begin: Alignment.topCenter,
            end: Alignment.bottomCenter,
            colors: [Color(0xFFE0F9FF), Colors.white, Colors.white],
            stops: [0, 0.3, 1],
          ),
        ),
        child: Stack(
          clipBehavior: Clip.none,
          children: [
            Padding(
              // 对标 padding: 42rpx 28rpx 28rpx
              padding: EdgeInsets.fromLTRB(14.w, 21.h, 14.w, 14.h),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: content,
              ),
            ),
            // 对标 .analysis-left-bg（156rpx，left -2rpx，top -36rpx）
            Positioned(
              left: -1.w,
              top: -18.h,
              child: CachedNetworkImage(
                imageUrl:
                    ImgUrl.build('/StaticResource/2026-04-16/analysis.png'),
                width: 78.w,
                placeholder: (_, _) => SizedBox(width: 78.w),
                errorWidget: (_, _, _) => SizedBox(width: 78.w),
              ),
            ),
            // 对标 .analysis-right-icon（180rpx，right -10rpx）
            Positioned(
              right: -5.w,
              top: 0,
              child: CachedNetworkImage(
                imageUrl: ImgUrl.build(
                    '/StaticResource/2026-04-08/analysis-right-icon.png'),
                width: 90.w,
                placeholder: (_, _) => SizedBox(width: 90.w),
                errorWidget: (_, _, _) => SizedBox(width: 90.w),
              ),
            ),
          ],
        ),
      ),
    );
  }

  // ===================== 状态条 / 答案标题 / 答案内容 =====================

  /// 对标 .obj-options-li-view-correct / error
  Widget _buildStatusStrip(QuestionModel data) {
    final status = data.answerStatus;
    final isCorrect = status == 10;
    final text = isCorrect
        ? '作答正确'
        : status == 11
            ? '作答有误'
            : status == 12
                ? '部分正确'
                : '未作答';
    final color = isCorrect ? ExerciseColors.correct : ExerciseColors.error;
    final icon = isCorrect
        ? '/StaticResource/2026-06-01/correct-icon1780284329572.png'
        : '/StaticResource/2026-06-01/error-icon1780284292405.png';

    return GradientBorderBox(
      state: isCorrect ? ExerciseTileState.correct : ExerciseTileState.error,
      padding: EdgeInsets.all(12.w),
      child: Row(
        mainAxisSize: MainAxisSize.max,
        children: [
          CachedNetworkImage(
            imageUrl: ImgUrl.build(icon),
            width: 20.w,
            height: 20.w,
            placeholder: (_, _) => SizedBox(width: 20.w, height: 20.w),
            errorWidget: (_, _, _) => SizedBox(width: 20.w, height: 20.w),
          ),
          SizedBox(width: 10.w),
          Text(
            text,
            style: TextStyle(fontSize: 16.sp, color: color),
          ),
        ],
      ),
    );
  }

  /// 对标 .answer-box-title（title-bacs.png，bottom right，119rpx）
  Widget _buildAnswerTitle(String text, {double? fontSize}) {
    return Stack(
      children: [
        // 标题装饰底图：固定尺寸，位置可调（对标 background-size: 119rpx auto）
        Positioned(
          right: 10.w,
          bottom: 0,
          child: Image.network(
            ImgUrl.build('/StaticResource/2026-04-01/title-bacs.png'),
            width: 59.5.w,
            height: 9.h,
            fit: BoxFit.fill,
            errorBuilder: (_, _, _) => const SizedBox.shrink(),
          ),
        ),
        Padding(
          padding: EdgeInsets.only(right: 14.w),
          child: Text(
            text,
            style: TextStyle(
              fontSize: fontSize ?? 15.sp,
              fontWeight: FontWeight.w600,
              color: ExerciseColors.title,
            ),
          ),
        ),
      ],
    );
  }

  /// 对标 .answer-box-content（富文本）
  Widget _buildAnswerContent(String html, Color color) {
    return Container(
      width: double.infinity,
      margin: EdgeInsets.symmetric(vertical: 12.h),
      padding: EdgeInsets.all(12.w),
      decoration: BoxDecoration(
        color: ExerciseColors.bg,
        borderRadius: BorderRadius.circular(14.r),
      ),
      child: RichTextContent(
        html: cleanRichText(html),
        textStyle: TextStyle(fontSize: 16.sp, color: color),
      ),
    );
  }

  /// 对标 .answer-box-content（纯文本：wrongReason / wrongAdvice）
  Widget _buildPlainContent(String text, Color color) {
    return Container(
      width: double.infinity,
      margin: EdgeInsets.symmetric(vertical: 12.h),
      padding: EdgeInsets.all(12.w),
      decoration: BoxDecoration(
        color: ExerciseColors.bg,
        borderRadius: BorderRadius.circular(14.r),
      ),
      child: Text(
        text,
        style: TextStyle(fontSize: 16.sp, color: color, height: 1.5),
      ),
    );
  }

  /// 对标 child.answerAnalysis?.analysis || child.analysis || child.answerAnalysis
  String _analysisText(QuestionModel q) {
    final raw = q.answerAnalysisRaw;
    if (raw is Map) {
      final first = '${raw['analysis'] ?? ''}';
      if (first.isNotEmpty) return first;
    }
    if (q.analysis.isNotEmpty) return q.analysis;
    if (raw != null && '$raw'.isNotEmpty) return '$raw';
    return '';
  }
}