import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../models/org_node.dart';
import '../../models/store_info.dart';
import '../../services/device_service.dart';
import '../../services/org_service.dart';

/// 设备分组页：门店选择、分组列表、新增/编辑/删除。
class DeviceGroupPage extends ConsumerStatefulWidget {
  const DeviceGroupPage({super.key});

  @override
  ConsumerState<DeviceGroupPage> createState() => _DeviceGroupPageState();
}

class _DeviceGroupPageState extends ConsumerState<DeviceGroupPage> {
  final OrgService _orgService = OrgService();
  final DeviceService _deviceService = DeviceService();
  final _scrollController = ScrollController();

  List<StoreInfo> _stores = [];
  String? _selectedStoreId;
  bool _loadingStores = true;

  List<OrgNode> _items = [];
  bool _loading = false;
  bool _hasMore = true;
  int _page = 1;
  String? _error;

  @override
  void initState() {
    super.initState();
    _scrollController.addListener(_onScroll);
    _loadStores();
  }

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

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

  Future<void> _loadStores() async {
    try {
      final stores = await _orgService.getMyStores();
      if (!mounted) return;
      setState(() {
        _stores = stores;
        _loadingStores = false;
        if (stores.isNotEmpty) {
          _selectedStoreId = stores.first.orgId;
        }
      });
      if (_selectedStoreId != null) {
        _loadData();
      }
    } catch (e) {
      if (!mounted) return;
      setState(() => _loadingStores = false);
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('门店列表加载失败：$e')),
      );
    }
  }

  Future<void> _loadData() async {
    if (_selectedStoreId == null) return;
    setState(() {
      _loading = true;
      _error = null;
      _page = 1;
      _hasMore = true;
    });
    try {
      final items = await _deviceService.getDeviceGroupList(
        page: 1,
        limit: 20,
        storeId: _selectedStoreId!,
      );
      if (!mounted) return;
      setState(() {
        _items = items;
        _hasMore = items.length >= 20;
        _loading = false;
      });
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _error = '$e';
        _loading = false;
      });
    }
  }

  Future<void> _loadMore() async {
    if (_loading || !_hasMore || _selectedStoreId == null) return;
    setState(() => _loading = true);
    try {
      final items = await _deviceService.getDeviceGroupList(
        page: _page + 1,
        limit: 20,
        storeId: _selectedStoreId!,
      );
      if (!mounted) return;
      setState(() {
        _page++;
        _items.addAll(items);
        _hasMore = items.length >= 20;
        _loading = false;
      });
    } catch (e) {
      if (!mounted) return;
      setState(() => _loading = false);
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('加载更多失败：$e')),
      );
    }
  }

  Future<void> _deleteGroup(OrgNode group) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('删除分组'),
        content: Text('确定要删除分组「${group.name}」吗？'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx, false),
            child: const Text('取消'),
          ),
          TextButton(
            onPressed: () => Navigator.pop(ctx, true),
            style: TextButton.styleFrom(foregroundColor: Colors.red),
            child: const Text('删除'),
          ),
        ],
      ),
    );
    if (confirmed != true) return;

    try {
      await _deviceService.deleteDeviceGroups([group.id]);
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('分组已删除')),
      );
      _loadData();
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('删除失败：$e')),
      );
    }
  }

  void _showAddEditSheet({OrgNode? group}) {
    if (_selectedStoreId == null) return;
    showModalBottomSheet(
          useSafeArea: true,
      context: context,
      isScrollControlled: true,
      builder: (ctx) => _GroupFormSheet(
        deviceService: _deviceService,
        storeId: _selectedStoreId!,
        group: group,
        onSaved: () {
          Navigator.pop(ctx);
          _loadData();
        },
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        automaticallyImplyLeading: false,
        title: const Text('设备分组'),
      ),
      body: Column(
        children: [
          _buildStoreSelector(),
          const Divider(height: 1),
          Expanded(child: _buildBody()),
        ],
      ),
      floatingActionButton: _selectedStoreId == null
          ? null
          : FloatingActionButton(
              onPressed: () => _showAddEditSheet(),
              child: const Icon(Icons.add),
            ),
    );
  }

  Widget _buildStoreSelector() {
    if (_loadingStores) {
      return const Padding(
        padding: EdgeInsets.all(16),
        child: Center(child: CircularProgressIndicator()),
      );
    }
    if (_stores.isEmpty) {
      return const Padding(
        padding: EdgeInsets.all(16),
        child: Text('暂无可选门店'),
      );
    }
    return Padding(
      padding: const EdgeInsets.fromLTRB(16, 8, 16, 8),
      child: DropdownButtonFormField<String>(
        value: _selectedStoreId,
        decoration: const InputDecoration(
          labelText: '选择门店',
          border: OutlineInputBorder(),
          prefixIcon: Icon(Icons.store),
        ),
        items: _stores
            .map((s) => DropdownMenuItem(
                  value: s.orgId,
                  child: Text(s.name),
                ))
            .toList(),
        onChanged: (v) {
          setState(() => _selectedStoreId = v);
          _loadData();
        },
      ),
    );
  }

  Widget _buildBody() {
    if (_selectedStoreId == null) {
      return const Center(child: Text('请先选择门店'));
    }
    if (_loading && _items.isEmpty) {
      return const Center(child: CircularProgressIndicator());
    }
    if (_error != null && _items.isEmpty) {
      return Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text('加载失败：$_error'),
            const SizedBox(height: 8),
            FilledButton.tonal(
              onPressed: _loadData,
              child: const Text('重试'),
            ),
          ],
        ),
      );
    }
    if (_items.isEmpty) {
      return RefreshIndicator(
        onRefresh: _loadData,
        child: ListView(
          physics: const AlwaysScrollableScrollPhysics(),
          children: const [
            SizedBox(height: 200),
            Center(child: Text('暂无分组数据')),
          ],
        ),
      );
    }
    return RefreshIndicator(
      onRefresh: _loadData,
      child: ListView.builder(
        controller: _scrollController,
        physics: const AlwaysScrollableScrollPhysics(),
        itemCount: _items.length + 1,
        itemBuilder: (context, index) {
          if (index == _items.length) {
            return _loading
                ? const Padding(
                    padding: EdgeInsets.all(16),
                    child: Center(child: CircularProgressIndicator()),
                  )
                : const SizedBox.shrink();
          }
          final group = _items[index];
          return _GroupListTile(
            group: group,
            onEdit: () => _showAddEditSheet(group: group),
            onDelete: () => _deleteGroup(group),
          );
        },
      ),
    );
  }
}

/// 分组列表项。
class _GroupListTile extends StatelessWidget {
  const _GroupListTile({
    required this.group,
    required this.onEdit,
    required this.onDelete,
  });

  final OrgNode group;
  final VoidCallback onEdit;
  final VoidCallback onDelete;

  @override
  Widget build(BuildContext context) {
    return Card(
      margin: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
      child: ListTile(
        leading: const CircleAvatar(
          child: Icon(Icons.folder_outlined),
        ),
        title: Text(group.name),
        subtitle: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const SizedBox(height: 4),
            if (group.address.isNotEmpty)
              _line(Icons.location_on, group.address),
            if (group.contactPhone.isNotEmpty)
              _line(Icons.phone, group.contactPhone),
            _line(Icons.tag, 'ID: ${group.id}'),
          ],
        ),
        trailing: PopupMenuButton<String>(
          onSelected: (value) {
            if (value == 'edit') {
              onEdit();
            } else if (value == 'delete') {
              onDelete();
            }
          },
          itemBuilder: (ctx) => [
            const PopupMenuItem(value: 'edit', child: Text('编辑')),
            const PopupMenuItem(value: 'delete', child: Text('删除')),
          ],
        ),
      ),
    );
  }

  Widget _line(IconData icon, String text) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 1),
      child: Row(
        children: [
          Icon(icon, size: 14, color: Colors.grey),
          const SizedBox(width: 4),
          Expanded(child: Text(text, style: const TextStyle(fontSize: 13))),
        ],
      ),
    );
  }
}

/// 新增/编辑分组表单。
class _GroupFormSheet extends StatefulWidget {
  const _GroupFormSheet({
    required this.deviceService,
    required this.storeId,
    this.group,
    required this.onSaved,
  });

  final DeviceService deviceService;
  final String storeId;
  final OrgNode? group;
  final VoidCallback onSaved;

  @override
  State<_GroupFormSheet> createState() => _GroupFormSheetState();
}

class _GroupFormSheetState extends State<_GroupFormSheet> {
  final _formKey = GlobalKey<FormState>();
  final _nameController = TextEditingController();
  bool _saving = false;

  @override
  void initState() {
    super.initState();
    if (widget.group != null) {
      _nameController.text = widget.group!.name;
    }
  }

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

  Future<void> _save() async {
    if (!_formKey.currentState!.validate()) return;
    setState(() => _saving = true);
    try {
      final data = <String, dynamic>{
        'name': _nameController.text.trim(),
        'storeId': widget.storeId,
        if (widget.group != null) 'id': widget.group!.id,
      };
      if (widget.group != null) {
        await widget.deviceService.updateDeviceGroup(data);
      } else {
        await widget.deviceService.saveDeviceGroup(data);
      }
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(widget.group != null ? '分组已更新' : '分组已创建'),
        ),
      );
      widget.onSaved();
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('保存失败：$e')),
      );
    } finally {
      if (mounted) setState(() => _saving = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final isEdit = widget.group != null;
    return SingleChildScrollView(
      padding: EdgeInsets.only(
        bottom: MediaQuery.of(context).viewInsets.bottom,
      ),
      child: Container(
        padding: const EdgeInsets.all(20),
        child: Form(
          key: _formKey,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            mainAxisSize: MainAxisSize.min,
            children: [
              Text(
                isEdit ? '编辑分组' : '新增分组',
                style: Theme.of(context)
                    .textTheme
                    .titleLarge
                    ?.copyWith(fontWeight: FontWeight.bold),
              ),
              const SizedBox(height: 20),
              TextFormField(
                controller: _nameController,
                decoration: const InputDecoration(
                  labelText: '分组名称',
                  border: OutlineInputBorder(),
                  prefixIcon: Icon(Icons.folder),
                ),
                validator: (v) =>
                    v == null || v.trim().isEmpty ? '请输入分组名称' : null,
              ),
              const SizedBox(height: 24),
              SizedBox(
                width: double.infinity,
                child: FilledButton(
                  onPressed: _saving ? null : _save,
                  child: _saving
                      ? const SizedBox(
                          height: 20,
                          width: 20,
                          child: CircularProgressIndicator(strokeWidth: 2),
                        )
                      : Text(isEdit ? '保存' : '创建'),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}