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 仍然尝试解析（兼容旧结构），但在扁平模式下不会使用
    final rawChildren = json['children'];
    List<Category> childrenList = [];
    if (rawChildren is List) {
      childrenList = rawChildren
          .where((e) => e != null)
          .map((e) {
        if (e is Map<String, dynamic>) {
          return Category.fromJson(e);
        } else if (e is Map) {
          return Category.fromJson(Map<String, dynamic>.from(e));
        } else {
          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 = '';

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

  final TextEditingController _searchController = TextEditingController();

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

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

  Future<void> _loadData() async {
    try {
      final result = await ApiService.getWorkAreaList();
      List<dynamic> raw = result['varList'] ?? [];

      // 解析为 Category 列表（可能包含 children）
      final parsed = 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();

      // 扁平化：父与子都放到同一列表中（以兼容后端可能还是两层结构）
      final List<Category> flat = [];
      for (final c in parsed) {
        flat.add(c);
        if (c.children.isNotEmpty) {
          flat.addAll(c.children);
        }
      }

      // 规范化 id：如果后端 ID 为空，则为该项赋予一个独一无二的占位 id，
      // 避免与默认 selectedId = '' 冲突导致“全部被选中”的问题。
      final List<Category> normalized = [];
      for (var i = 0; i < flat.length; i++) {
        final c = flat[i];
        final rawId = (c.ELECTRONIC_FENCE_AREA_ID ?? '').toString().trim();
        if (rawId.isEmpty) {
          // 生成占位 id（基于索引和 name hash，足够唯一且不会是空字符串）
          final generatedId = '__generated_${i}_${c.name.hashCode}';
          normalized.add(Category(
            ELECTRONIC_FENCE_AREA_ID: generatedId,
            name: c.name,
            POSITIONS: c.POSITIONS,
            children: const [],
          ));
        } else {
          // 保持原 id
          normalized.add(Category(
            ELECTRONIC_FENCE_AREA_ID: rawId,
            name: c.name,
            POSITIONS: c.POSITIONS,
            children: const [],
          ));
        }
      }

      setState(() {
        original = normalized;
        filtered = original;
        loading = false;
      });
    } catch (e, st) {
      debugPrint('WorkAreaPicker._loadData error: $e\n$st');
      setState(() => loading = false);
    }
  }

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

  // 扁平过滤：在 name 或 POSITIONS 中搜索
  List<Category> _filterCategories(List<Category> list, String query) {
    if (query.isEmpty) return list;
    final q = query.toLowerCase();
    return list.where((c) {
      final name = (c.name ?? '').toLowerCase();
      final pos = (c.POSITIONS ?? '').toLowerCase();
      return name.contains(q) || pos.contains(q);
    }).toList();
  }

  Widget _buildRow(Category cat) {
    final isSelected = selectedId == cat.ELECTRONIC_FENCE_AREA_ID;
    return InkWell(
      onTap: () {
        setState(() {
          selectedId = cat.ELECTRONIC_FENCE_AREA_ID;
          selectedName = cat.name;
          selected_POSITIONS = cat.POSITIONS;
        });
      },
      child: Container(
        color: Colors.white,
        padding: const EdgeInsets.symmetric(vertical: 12, horizontal: 12),
        child: Row(
          children: [
            Expanded(child: Text(cat.name)),
            Icon(
              isSelected ? Icons.radio_button_checked : Icons.radio_button_unchecked,
              color: isSelected ? Colors.green : Colors.grey,
            ),
          ],
        ),
      ),
    );
  }

  @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),
                  ),
                ),
              ],
            ),
          ),
          const Divider(height: 1),
          Expanded(
            child: loading
                ? const Center(child: CircularProgressIndicator())
                : (filtered.isEmpty
                ? const Center(child: Text('没有找到匹配的工作区域'))
                : Container(
              color: Colors.white,
              child: ListView.builder(
                itemCount: filtered.length,
                itemBuilder: (ctx, idx) => _buildRow(filtered[idx]),
              ),
            )),
          ),
        ],
      ),
    );
  }
}