import 'package:flutter/material.dart';
import 'package:qhd_prevention/customWidget/search_bar_widget.dart';
import 'package:qhd_prevention/customWidget/custom_button.dart';
import 'package:qhd_prevention/http/modules/basic_info_api.dart';
import 'package:qhd_prevention/http/ApiService.dart';

// 数据字典模型
class DictCategory {
  final String id;
  final String name;
  final Map<String, dynamic> extValues;
  final String parentId;
  final String dictValue;
  final String dictLabel;
  final List<DictCategory> children;

  late final String dingValue;
  late final String dingName;

  DictCategory({
    required this.id,
    required this.name,
    required this.children,
    required this.extValues,
    required this.parentId,
    required this.dictValue,
    required this.dictLabel,
    required this.dingValue,
    required this.dingName,
  });

  factory DictCategory.fromJson(Map<String, dynamic> json) {
    String parseString(dynamic v) {
      if (v == null) return '';
      if (v is String) return v;
      return v.toString();
    }

    final rawChildren = json['children'];
    List<DictCategory> childrenList = [];
    if (rawChildren is List) {
      try {
        childrenList = rawChildren
            .where((e) => e != null)
            .map((e) => DictCategory.fromJson(Map<String, dynamic>.from(e as Map)))
            .toList();
      } catch (e) {
        childrenList = [];
      }
    }

    final extRaw = json['extValues'];
    Map<String, dynamic> extMap = {};
    if (extRaw is Map) {
      extMap = Map<String, dynamic>.from(extRaw);
    }

    return DictCategory(
      id: parseString(json['id']),
      name: parseString(json['dictLabel'] ?? json['name']),
      children: childrenList,
      extValues: extMap,
      parentId: parseString(json['parentId']),
      dictValue: parseString(json['dictValue']),
      dictLabel: parseString(json['dictLabel'] ?? json['name']),
      dingValue: "",
      dingName: "",
    );
  }

  Map<String, dynamic> toMap() {
    return {
      'id': id,
      'name': name,
      'dictValue': dictValue,
      'dictLabel': dictLabel,
      'parentId': parentId,
      'extValues': extValues,
    };
  }
}

typedef DictSelectCallback = void Function(String id, String name, Map<String, dynamic>? extraData);

class MultiDictValuesPicker extends StatefulWidget {
  final String dictType;
  final DictSelectCallback onSelected;
  final bool showSearch;
  final String title;
  final String confirmText;
  final String cancelText;
  final bool showIgnoreHidden;
  final bool isSafeChekDangerLevel;
  final bool allowSelectParent;

  const MultiDictValuesPicker({
    Key? key,
    required this.dictType,
    required this.onSelected,
    this.showSearch = true,
    this.title = '请选择',
    this.confirmText = '确定',
    this.cancelText = '取消',
    this.isSafeChekDangerLevel = false,
    this.showIgnoreHidden = false,
    this.allowSelectParent = true,
  }) : super(key: key);

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

class _MultiDictValuesPickerState extends State<MultiDictValuesPicker> {
  String selectedId = '';
  String selectedName = '';
  Map<String, dynamic>? selectedExtraData;
  Set<String> expandedSet = {};

  List<DictCategory> original = [];
  List<DictCategory> filtered = [];
  bool loading = true;
  bool error = false;
  String errorMessage = '';

  String dingValueWai = '';
  String dingNameWai = '';

  final TextEditingController _searchController = TextEditingController();

  // id -> node 映射，用于快速查父节点
  final Map<String, DictCategory> _idMap = {};

  @override
  void initState() {
    super.initState();
    selectedId = '';
    selectedName = '';
    expandedSet = {};
    _searchController.addListener(_onSearchChanged);
    _loadDictData();
  }

  @override
  void dispose() {
    _searchController.removeListener(_onSearchChanged);
    _searchController.dispose();
    super.dispose();
  }

  Future<void> _loadDictData() async {
    try {
      setState(() {
        loading = true;
        error = false;
      });

      final result = await BasicInfoApi.getDictValues(widget.dictType);
      List<dynamic> raw = result['data'] as List<dynamic>;

      if (!widget.showIgnoreHidden) {
        if (widget.dictType == 'hiddenLevel') {
          for (int i = 0; i < raw.length; i++) {
            if (raw[i]['children'] != null) {
              raw[i]['children'].removeWhere((child) => child != null && child['dictLabel'] == '忽略隐患');
            }
          }
        }
      }

      late List<dynamic> resultRows = [];
      if (widget.isSafeChekDangerLevel) {
        if (widget.dictType == 'hiddenLevel') {
          for (int i = 0; i < raw.length; i++) {
            if (raw[i]['children'] != null) {
              for (int m = 0; m < raw[i]['children'].length; m++) {
                final ch = raw[i]['children'][m];
                if (ch != null && (ch['dictLabel'] == '轻微隐患' || ch['dictLabel'] == '一般隐患')) {
                  resultRows.add(ch);
                }
              }
            }
          }
        } else {
          resultRows = raw;
        }
      } else {
        resultRows = raw;
      }

      // 转换为 DictCategory 列表
      final loaded = resultRows.map((e) => DictCategory.fromJson(e as Map<String, dynamic>)).toList();

      // 构建 id map（包含所有节点的扁平映射）
      _idMap.clear();
      void buildIdMap(List<DictCategory> nodes) {
        for (final n in nodes) {
          _idMap[n.id] = n;
          if (n.children.isNotEmpty) {
            buildIdMap(n.children);
          }
        }
      }

      buildIdMap(loaded);

      setState(() {
        original = loaded;
        filtered = original;
        loading = false;
      });
    } catch (e) {
      setState(() {
        loading = false;
        error = true;
        errorMessage = e.toString();
      });
    }
  }

  void _onSearchChanged() {
    final query = _searchController.text.toLowerCase().trim();
    setState(() {
      filtered = query.isEmpty ? original : _filterCategories(original, query);
      if (query.isNotEmpty) {
        expandedSet.addAll(_getAllExpandableIds(filtered));
      }
    });
  }

  Set<String> _getAllExpandableIds(List<DictCategory> categories) {
    Set<String> ids = {};
    for (var category in categories) {
      if (category.children.isNotEmpty) {
        ids.add(category.id);
        ids.addAll(_getAllExpandableIds(category.children));
      }
    }
    return ids;
  }

  List<DictCategory> _filterCategories(List<DictCategory> list, String query) {
    List<DictCategory> result = [];
    for (var cat in list) {
      final children = _filterCategories(cat.children, query);
      if (cat.name.toLowerCase().contains(query) || children.isNotEmpty) {
        result.add(
          DictCategory(
            id: cat.id,
            name: cat.name,
            children: children,
            extValues: cat.extValues,
            parentId: cat.parentId,
            dictValue: cat.dictValue,
            dictLabel: cat.dictLabel,
            dingValue: "",
            dingName: "",
          ),
        );
      }
    }
    return result;
  }

  // 判断节点是否可选
  bool _isSelectableNode(DictCategory category) {
    if (widget.allowSelectParent) {
      return true;
    }
    return category.children.isEmpty;
  }

  // 查找某个 id 的最上层祖先节点（若自身就是顶层则返回自身）
  DictCategory? _getTopAncestor(String id) {
    if (id.isEmpty) return null;
    DictCategory? current = _idMap[id];
    if (current == null) return null;
    // 如果没有 parentId 或 parentId 为空，当前即为顶层
    while (current != null && current.parentId.isNotEmpty) {
      final parent = _idMap[current.parentId];
      if (parent == null) break;
      current = parent;
    }
    return current;
  }

  Widget _buildRow(DictCategory category, int indent) {
    final hasChildren = category.children.isNotEmpty;
    final isExpanded = expandedSet.contains(category.id);
    final isSelected = category.id == selectedId;
    final isSelectable = _isSelectableNode(category);

    return Column(
      children: [
        InkWell(
          onTap: () {
            setState(() {
              if (hasChildren) {
                isExpanded ? expandedSet.remove(category.id) : expandedSet.add(category.id);
              }
              if (isSelectable) {
                selectedId = category.id;
                selectedName = category.name;
                selectedExtraData = category.toMap();

                // 计算最上层父节点（如果存在）
                final top = _getTopAncestor(category.id);
                if (top != null) {
                  dingValueWai = top.dictValue;
                  dingNameWai = top.name;
                } else {
                  // 回退到自身值（防御）
                  dingValueWai = category.dictValue;
                  dingNameWai = category.name;
                }
              }
            });
          },
          child: Container(
            color: Colors.white,
            child: Row(
              children: [
                SizedBox(width: 16.0 * indent),
                SizedBox(
                  width: 24,
                  child: hasChildren
                      ? Icon(
                    isExpanded ? Icons.arrow_drop_down_rounded : Icons.arrow_right_rounded,
                    size: 35,
                    color: Colors.grey[600],
                  )
                      : const SizedBox.shrink(),
                ),
                const SizedBox(width: 5),
                Expanded(
                  child: Padding(
                    padding: const EdgeInsets.symmetric(vertical: 12),
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          category.name,
                          style: TextStyle(
                            fontWeight: isSelected ? FontWeight.bold : FontWeight.normal,
                            color: Colors.black,
                          ),
                        ),
                      ],
                    ),
                  ),
                ),
                Padding(
                  padding: const EdgeInsets.symmetric(horizontal: 16),
                  child: isSelectable
                      ? Icon(
                    isSelected ? Icons.radio_button_checked : Icons.radio_button_unchecked,
                    color: Colors.blue,
                  )
                      : null,
                ),
              ],
            ),
          ),
        ),
        if (hasChildren && isExpanded) ...category.children.map((child) => _buildRow(child, indent + 1)),
      ],
    );
  }

  Widget _buildTitleBar() {
    return Container(
      color: Colors.white,
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
      child: Center(
        child: Text(
          widget.title,
          style: const TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
        ),
      ),
    );
  }

  Widget _buildActionBar() {
    return Container(
      color: Colors.white,
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      child: Row(
        children: [
          GestureDetector(
            onTap: () => Navigator.of(context).pop(),
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
              child: Text(widget.cancelText, style: const TextStyle(fontSize: 16, color: Colors.grey)),
            ),
          ),
          if (widget.showSearch) ...[
            Expanded(
              child: Padding(
                padding: const EdgeInsets.symmetric(horizontal: 12),
                child: SearchBarWidget(controller: _searchController, isShowSearchButton: false, onSearch: (keyboard) {}),
              ),
            ),
          ] else
            const Expanded(child: SizedBox()),
          GestureDetector(
            onTap: selectedId.isEmpty
                ? null
                : () {
              // 在返回之前，将最上层父节点信息也回传（保证 selectedExtraData 存在）
              final top = _getTopAncestor(selectedId);
              if (top != null) {
                selectedExtraData ??= {};
                selectedExtraData!['dingValue'] = top.dictValue;
                selectedExtraData!['dingName'] = top.name;
              } else {
                selectedExtraData ??= {};
                selectedExtraData!['dingValue'] = dingValueWai;
                selectedExtraData!['dingName'] = dingNameWai;
              }

              Navigator.of(context).pop();
              widget.onSelected(selectedId, selectedName, selectedExtraData);
            },
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
              child: Text(
                widget.confirmText,
                style: TextStyle(
                  fontSize: 16,
                  color: selectedId.isEmpty ? Colors.grey : Colors.blue,
                  fontWeight: FontWeight.bold,
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildContent() {
    if (loading) {
      return const Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [CircularProgressIndicator(), SizedBox(height: 16), Text('加载中...')],
        ),
      );
    }

    if (error) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Icon(Icons.error_outline, size: 48, color: Colors.red),
            const SizedBox(height: 16),
            const Text('加载失败', style: TextStyle(fontSize: 16)),
            const SizedBox(height: 8),
            Text(errorMessage, style: const TextStyle(fontSize: 12, color: Colors.grey), textAlign: TextAlign.center),
            const SizedBox(height: 16),
            CustomButton(text: '重试', onPressed: _loadDictData),
          ],
        ),
      );
    }

    if (filtered.isEmpty) {
      return const Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [Icon(Icons.search_off, size: 48, color: Colors.grey), SizedBox(height: 16), Text('暂无数据', style: TextStyle(fontSize: 16, color: Colors.grey))],
        ),
      );
    }

    return Container(
      color: Colors.white,
      child: ListView.builder(
        itemCount: filtered.length,
        itemBuilder: (ctx, idx) => _buildRow(filtered[idx], 0),
      ),
    );
  }

  Widget _buildHintMessage() {
    if (!widget.allowSelectParent) {
      return Container(
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
        color: Colors.blue[50],
        child: Row(
          children: [
            Icon(Icons.info_outline, size: 16, color: Colors.blue[700]),
            const SizedBox(width: 8),
            Expanded(child: Text('只能选择没有子项的节点', style: TextStyle(fontSize: 12, color: Colors.blue[700]))),
          ],
        ),
      );
    }
    return const SizedBox.shrink();
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      width: MediaQuery.of(context).size.width,
      height: MediaQuery.of(context).size.height * 0.7,
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: const BorderRadius.only(topLeft: Radius.circular(12), topRight: Radius.circular(12)),
        boxShadow: [BoxShadow(color: Colors.black.withOpacity(0.1), blurRadius: 10, offset: const Offset(0, -2))],
      ),
      child: Column(
        children: [
          _buildActionBar(),
          const Divider(height: 1),
          Expanded(child: _buildContent()),
        ],
      ),
    );
  }
}