import 'package:asset_assistant/pages/country_add_page.dart';
import 'package:asset_assistant/utils/host_utils.dart';
import 'package:flutter/material.dart';
import 'package:dio/dio.dart';

// 国家数据模型（flag字段存储emoji）
class Country {
  final String countryId;
  final String name;
  final String code;
  final String? flag; // 国旗字段，存储emoji

  Country({
    required this.countryId,
    required this.name,
    required this.code,
    this.flag,
  });

  // 从JSON构建对象
  factory Country.fromJson(Map<String, dynamic> json) {
    return Country(
      countryId: json['country_id'],
      name: json['name'],
      code: json['code'],
      flag: json['flag'], // 解析emoji字段
    );
  }
}

// 接口响应模型
class CountryResponse {
  final bool success;
  final String message;
  final CountryData data;

  CountryResponse({
    required this.success,
    required this.message,
    required this.data,
  });

  factory CountryResponse.fromJson(Map<String, dynamic> json) {
    return CountryResponse(
      success: json['success'],
      message: json['message'],
      data: CountryData.fromJson(json['data']),
    );
  }
}

// 响应数据模型
class CountryData {
  final int total;
  final int page;
  final int pageSize;
  final List<Country> items;

  CountryData({
    required this.total,
    required this.page,
    required this.pageSize,
    required this.items,
  });

  factory CountryData.fromJson(Map<String, dynamic> json) {
    var itemsList = json['items'] as List? ?? [];
    List<Country> items = itemsList.map((i) => Country.fromJson(i)).toList();

    return CountryData(
      total: json['total'],
      page: json['page'],
      pageSize: json['page_size'],
      items: items,
    );
  }
}

class CountryPage extends StatefulWidget {
  const CountryPage({super.key});

  @override
  State<CountryPage> createState() => _CountryPageState();
}

class _CountryPageState extends State<CountryPage> {
  List<Country> _countries = [];
  bool _isLoading = true;
  String? _errorMessage;
  int _currentPage = 1;
  final int _pageSize = 20;
  bool _hasMoreData = true;
  late ScrollController _scrollController;

  @override
  void initState() {
    super.initState();
    _scrollController = ScrollController();
    _scrollController.addListener(_onScroll);
    _fetchCountries();
  }

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

  void _onScroll() {
    if (_isLoading) return;
    if (_hasMoreData &&
        _scrollController.position.pixels >=
            _scrollController.position.maxScrollExtent - 200) {
      _loadMore();
    }
  }

  Future<void> _fetchCountries({bool isRefresh = false}) async {
    if (isRefresh) {
      setState(() {
        _currentPage = 1;
        _hasMoreData = true;
      });
    }

    if (!_hasMoreData && !isRefresh) return;

    setState(() {
      _isLoading = true;
    });

    try {
      final baseUrl = HostUtils().currentHost;
      final path = '/country/read';
      final url = '$baseUrl$path';
      debugPrint('====== 开始请求国家列表 ======');
      debugPrint('请求URL: $url');
      debugPrint('请求参数: page=$_currentPage, page_size=$_pageSize');

      final dio = Dio();
      final response = await dio.post(
        url,
        data: {
          'page': _currentPage,
          'page_size': _pageSize,
          'name': '',
          'code': '',
          'country_id': '',
          'flag': '',
        },
        options: Options(
          headers: {'Content-Type': 'application/x-www-form-urlencoded'},
        ),
      );

      debugPrint('请求成功，状态码: ${response.statusCode}');
      debugPrint('响应数据: ${response.data}');

      if (response.statusCode == 200) {
        final CountryResponse countryResponse = CountryResponse.fromJson(
          response.data,
        );

        if (countryResponse.success) {
          setState(() {
            if (isRefresh) {
              _countries = countryResponse.data.items;
            } else {
              _countries.addAll(countryResponse.data.items);
            }

            _hasMoreData = _countries.length < countryResponse.data.total;
            _currentPage++;
            _errorMessage = null;
          });
          debugPrint('数据解析成功，当前列表总数: ${_countries.length}');
          debugPrint('是否还有更多数据: $_hasMoreData，下一页: $_currentPage');
        } else {
          setState(() {
            _errorMessage = countryResponse.message;
          });
          debugPrint('接口返回失败: ${countryResponse.message}');
        }
      } else {
        setState(() {
          _errorMessage = '服务器响应异常: ${response.statusCode}';
        });
        debugPrint('服务器响应异常: ${response.statusCode}');
      }
    } on DioException catch (e) {
      String errorMsg = '网络请求失败';
      if (e.response != null) {
        errorMsg = '请求失败: ${e.response?.statusCode}';
        debugPrint(
          '请求错误，状态码: ${e.response?.statusCode}，响应数据: ${e.response?.data}',
        );
      } else if (e.type == DioExceptionType.connectionTimeout) {
        errorMsg = '连接超时，请检查网络';
        debugPrint('连接超时: ${e.message}');
      } else if (e.type == DioExceptionType.connectionError) {
        errorMsg = '网络连接错误';
        debugPrint('网络连接错误: ${e.message}');
      } else {
        debugPrint('Dio异常: ${e.type}，消息: ${e.message}');
      }
      setState(() {
        _errorMessage = errorMsg;
      });
    } catch (e) {
      setState(() {
        _errorMessage = '发生未知错误: $e';
      });
      debugPrint('未知错误: $e');
    } finally {
      setState(() {
        _isLoading = false;
      });
      debugPrint('====== 请求结束 ======\n');
    }
  }

  Future<void> _refresh() async {
    debugPrint('触发下拉刷新');
    await _fetchCountries(isRefresh: true);
  }

  void _loadMore() {
    if (!_isLoading && _hasMoreData) {
      debugPrint('触发加载更多，当前页: $_currentPage');
      _fetchCountries();
    }
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    return Scaffold(
      appBar: AppBar(
        title: const Text('国家列表'),
        centerTitle: true,
        elevation: 4,
        shadowColor: Colors.black12,
        backgroundColor: theme.colorScheme.surfaceContainerHighest,
        leading: IconButton(
          icon: const Icon(Icons.arrow_back),
          onPressed: () {
            Navigator.of(context).pop();
          },
        ),
        actions: [
          IconButton(
            icon: const Icon(Icons.add),
            onPressed: () async {
              debugPrint('点击新增按钮，跳转到新增页面');
              final result = await Navigator.push(
                context,
                MaterialPageRoute(builder: (context) => const AddCountryPage()),
              );
              if (result == true) {
                debugPrint('从新增页面返回，刷新列表数据');
                _fetchCountries(isRefresh: true);
              }
            },
          ),
        ],
      ),
      body: SafeArea(child: _buildBody(theme)),
    );
  }

  Widget _buildBody(ThemeData theme) {
    // 加载中且列表为空
    if (_isLoading && _countries.isEmpty) {
      return const Center(child: CircularProgressIndicator());
    }

    // 有错误信息且列表为空
    if (_errorMessage != null && _countries.isEmpty) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text(
              _errorMessage!,
              style: TextStyle(color: theme.colorScheme.error),
            ),
            const SizedBox(height: 16),
            ElevatedButton(
              onPressed: () => _fetchCountries(isRefresh: true),
              child: const Text('重试'),
            ),
          ],
        ),
      );
    }

    // 无数据状态（列表为空且无错误）
    if (_countries.isEmpty) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            // 无数据背景图标
            Icon(
              Icons.flag_outlined,
              size: 120,
              color: theme.colorScheme.onSurface.withOpacity(0.1),
            ),
            const SizedBox(height: 24),
            // 无数据提示文字
            Text(
              '暂无国家数据',
              style: theme.textTheme.titleLarge?.copyWith(
                color: theme.colorScheme.onSurface.withOpacity(0.5),
              ),
            ),
            const SizedBox(height: 16),
            // 刷新按钮
            IconButton(
              icon: Icon(
                Icons.refresh,
                size: 28,
                color: theme.colorScheme.primary,
              ),
              onPressed: () => _fetchCountries(isRefresh: true),
              tooltip: '刷新数据',
            ),
          ],
        ),
      );
    }

    // 正常列表展示
    return RefreshIndicator(
      onRefresh: _refresh,
      child: ListView.builder(
        padding: const EdgeInsets.symmetric(vertical: 8),
        itemCount: _countries.length + (_hasMoreData ? 1 : 0),
        itemBuilder: (context, index) {
          if (index < _countries.length) {
            final country = _countries[index];
            return _buildCountryItem(theme, country);
          } else {
            return Padding(
              padding: const EdgeInsets.symmetric(vertical: 16),
              child: Center(
                child: _isLoading
                    ? const CircularProgressIndicator()
                    : const Text('没有更多数据了'),
              ),
            );
          }
        },
        controller: _scrollController,
      ),
    );
  }

  Widget _buildCountryItem(ThemeData theme, Country country) {
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        Material(
          color: Colors.transparent,
          child: InkWell(
            onTap: () {
              // 可以添加点击事件
            },
            borderRadius: BorderRadius.circular(8),
            splashColor: theme.colorScheme.primary.withAlpha(26),
            highlightColor: theme.colorScheme.primary.withAlpha(13),
            child: Container(
              height: 64,
              padding: const EdgeInsets.symmetric(horizontal: 16),
              child: Row(
                children: [
                  // 国旗Emoji展示区域
                  Container(
                    width: 40,
                    height: 40,
                    decoration: BoxDecoration(
                      color: theme.colorScheme.surfaceContainerHighest,
                      borderRadius: BorderRadius.circular(8),
                    ),
                    child: Center(
                      child: Text(
                        // 显示国旗emoji，如果没有则显示默认图标
                        country.flag != null && country.flag!.isNotEmpty
                            ? country.flag!
                            : '',
                        style: const TextStyle(fontSize: 24), // 适当调整emoji大小
                      ),
                    ),
                  ),
                  const SizedBox(width: 16),
                  Expanded(
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          country.name,
                          style: theme.textTheme.titleMedium?.copyWith(
                            fontWeight: FontWeight.w500,
                            color: theme.colorScheme.onSurface,
                          ),
                        ),
                        const SizedBox(height: 4),
                        Text(
                          '代码: ${country.code}',
                          style: theme.textTheme.bodySmall?.copyWith(
                            color: theme.colorScheme.onSurfaceVariant,
                          ),
                        ),
                      ],
                    ),
                  ),
                  Icon(
                    Icons.arrow_forward_ios,
                    size: 18,
                    color: theme.hintColor,
                  ),
                ],
              ),
            ),
          ),
        ),
        Divider(
          height: 1,
          thickness: 1,
          indent: 72,
          endIndent: 16,
          color: theme.dividerColor,
        ),
      ],
    );
  }
}