flutter_integrated_whb/lib/pages/home/tap/workArea_picker.dart

import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:qhd_prevention/customWidget/search_bar_widget.dart';
import 'package:qhd_prevention/http/ApiService.dart';
import 'package:qhd_prevention/tools/tools.dart';

// ----- Models -----
class Category {
  final String ELECTRONIC_FENCE_AREA_ID;
  final String POSITIONS;
  final String name;
  final List<Category> children;

  Category({
    required this.ELECTRONIC_FENCE_AREA_ID,
    required this.name,
    this.POSITIONS = '',
    this.children = const [],
  });

  factory Category.fromJson(Map<String, dynamic> json) {
    // 保护式读取，避免 null 转 List、String 时抛异常
    final id = (json['ELECTRONIC_FENCE_AREA_ID'] ?? '').toString();
    final name = (json['name'] ?? '').toString();
    final positions = (json['POSITIONS'] ?? '').toString();

    // children 可能不存在、为 null、或已经是 List
    final rawChildren = json['children'];
    List<Category> childrenList = [];
    if (rawChildren is List) {
      childrenList = rawChildren
          .where((e) => e != null)
          .map((e) {
        // e 可能已经是 Map<String,dynamic> 或 dynamic
        if (e is Map<String, dynamic>) {
          return Category.fromJson(e);
        } else if (e is Map) {
          return Category.fromJson(Map<String, dynamic>.from(e));
        } else {
          // 无法解析的项跳过，或返回空占位
          return null;
        }
      })
          .whereType<Category>()
          .toList();
    }

    return Category(
      ELECTRONIC_FENCE_AREA_ID: id,
      name: name,
      POSITIONS: positions,
      children: childrenList,
    );
  }
}


typedef DeptSelectCallback =
    void Function(String id, String POSITIONS, String name);

class WorkAreaPicker extends StatefulWidget {
  final DeptSelectCallback onSelected;

  const WorkAreaPicker({Key? key, required this.onSelected}) : super(key: key);

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

class _WorkAreaPickerState extends State<WorkAreaPicker> {
  String selectedId = '';
  String selectedName = '';
  String selected_POSITIONS = '';

  Set<String> expandedSet = {};

  List<Category> original = [];
  List<Category> filtered = [];
  bool loading = true;

  final TextEditingController _searchController = TextEditingController();

  @override
  void initState() {
    super.initState();
    // 初始均为空
    selectedId = '';
    selectedName = '';
    selected_POSITIONS = '';
    expandedSet = {};
    _searchController.addListener(_onSearchChanged);
    _loadData();
  }

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

  Future<void> _loadData() async {
    try {
      final result = await ApiService.getWorkAreaList();
      final dynamic nodesField = result['zTreeNodes'];

      // nodesField 可能是已经解析过的 List 或者是 String（JSON 字符串）
      List<dynamic> raw;
      if (nodesField is String) {
        raw = json.decode(nodesField) as List<dynamic>;
      } else if (nodesField is List) {
        raw = nodesField;
      } else {
        raw = [];
      }

      // debug 打印（运行中可查看控制台）
      // print('raw length = ${raw.length}');

      setState(() {
        original = raw
            .map((e) {
          if (e is Map<String, dynamic>) return Category.fromJson(e);
          if (e is Map) return Category.fromJson(Map<String, dynamic>.from(e));
          return null;
        })
            .whereType<Category>()
            .toList();
        filtered = original;
        loading = false;
      });
    } catch (e, st) {
      // 打印错误以便调试
      // print('loadData error: $e\n$st');
      setState(() => loading = false);
    }
  }

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

  List<Category> _filterCategories(List<Category> list, String query) {
    List<Category> result = [];
    for (var cat in list) {
      final children = _filterCategories(cat.children, query);
      if (cat.name.toLowerCase().contains(query) || children.isNotEmpty) {
        result.add(
          Category(
            ELECTRONIC_FENCE_AREA_ID: cat.ELECTRONIC_FENCE_AREA_ID,
            name: cat.name,
            children: children,
          ),
        );
      }
    }
    return result;
  }

  Widget _buildRow(Category cat, int indent) {
    final hasChildren = cat.children.isNotEmpty;
    final isExpanded = expandedSet.contains(cat.ELECTRONIC_FENCE_AREA_ID);
    final isSelected = cat.ELECTRONIC_FENCE_AREA_ID == selectedId;
    return Column(
      children: [
        InkWell(
          onTap: () {
            setState(() {
              if (hasChildren) {
                isExpanded
                    ? expandedSet.remove(cat.ELECTRONIC_FENCE_AREA_ID)
                    : expandedSet.add(cat.ELECTRONIC_FENCE_AREA_ID);
              }
              selectedId = cat.ELECTRONIC_FENCE_AREA_ID;
              selectedName = cat.name;
              selected_POSITIONS = cat.POSITIONS;
            });
          },
          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: Text(cat.name),
                  ),
                ),
                Padding(
                  padding: const EdgeInsets.symmetric(horizontal: 16),
                  child: Icon(
                    isSelected
                        ? Icons.radio_button_checked
                        : Icons.radio_button_unchecked,
                    color: Colors.green,
                  ),
                ),
              ],
            ),
          ),
        ),
        if (hasChildren && isExpanded)
          ...cat.children.map((c) => _buildRow(c, indent + 1)),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      width: MediaQuery.of(context).size.width,
      height: MediaQuery.of(context).size.height * 0.7,
      color: Colors.white,
      child: Column(
        children: [
          Container(
            color: Colors.white,
            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
            child: Row(
              children: [
                GestureDetector(
                  onTap: () => Navigator.of(context).pop(),
                  child: const Text('取消', style: TextStyle(fontSize: 16)),
                ),
                Expanded(
                  child: Padding(
                    padding: const EdgeInsets.symmetric(horizontal: 12),
                    child: SearchBarWidget(
                      controller: _searchController,
                      isShowSearchButton: false,
                      onSearch: (keyboard) {},
                    ),
                  ),
                ),
                GestureDetector(
                  onTap: () {
                    Navigator.of(context).pop();
                    widget.onSelected(
                      selectedId,
                      selected_POSITIONS,
                      selectedName,
                    );
                  },
                  child: const Text(
                    '确定',
                    style: TextStyle(fontSize: 16, color: Colors.green),
                  ),
                ),
              ],
            ),
          ),
          Divider(),
          Expanded(
            child:
                loading
                    ? const Center(child: CircularProgressIndicator())
                    : Container(
                      color: Colors.white,
                      child: ListView.builder(
                        itemCount: filtered.length,
                        itemBuilder: (ctx, idx) => _buildRow(filtered[idx], 0),
                      ),
                    ),
          ),
        ],
      ),
    );
  }
}