import 'dart:async';
import 'package:flutter/material.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
import 'package:superport/models/user_model.dart';
import 'package:superport/screens/common/theme_shadcn.dart';
import 'package:superport/screens/common/components/shadcn_components.dart';
import 'package:superport/screens/common/layouts/base_list_screen.dart';
import 'package:superport/screens/common/widgets/standard_data_table.dart';
import 'package:superport/screens/common/widgets/standard_action_bar.dart';
import 'package:superport/screens/common/widgets/pagination.dart';
import 'package:superport/screens/user/controllers/user_list_controller.dart';
import 'package:superport/utils/constants.dart';

/// shadcn/ui 스타일로 재설계된 사용자 관리 화면
class UserList extends StatefulWidget {
  const UserList({super.key});

  @override
  State<UserList> createState() => _UserListState();
}

class _UserListState extends State<UserList> {
  late UserListController _controller;
  final TextEditingController _searchController = TextEditingController();
  
  @override
  void initState() {
    super.initState();
    
    _controller = UserListController();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      _controller.initialize(pageSize: 10);
    });
    
    _searchController.addListener(() {
      _onSearchChanged(_searchController.text);
    });
  }

  @override
  void dispose() {
    _controller.dispose();
    _searchController.dispose();
    super.dispose();
  }
  
  Timer? _debounce;
  void _onSearchChanged(String query) {
    if (_debounce?.isActive ?? false) _debounce?.cancel();
    _debounce = Timer(const Duration(milliseconds: 500), () {
      _controller.setSearchQuery(query);
    });
  }

  /// 사용자 권한 표시 배지
  Widget _buildUserRoleBadge(UserRole role) {
    final roleName = role.displayName;
    ShadcnBadgeVariant variant;
    
    switch (role) {
      case UserRole.admin:
        variant = ShadcnBadgeVariant.destructive;
        break;
      case UserRole.manager:
        variant = ShadcnBadgeVariant.primary;
        break;
      case UserRole.staff:
        variant = ShadcnBadgeVariant.secondary;
        break;
    }
    
    return ShadcnBadge(
      text: roleName,
      variant: variant,
      size: ShadcnBadgeSize.small,
    );
  }

  /// 사용자 추가 폼으로 이동
  void _navigateToAdd() async {
    final result = await Navigator.pushNamed(context, Routes.userAdd);
    if (result == true && mounted) {
      _controller.loadUsers(refresh: true);
    }
  }

  /// 사용자 수정 폼으로 이동
  void _navigateToEdit(int userId) async {
    final result = await Navigator.pushNamed(
      context,
      Routes.userEdit,
      arguments: userId,
    );
    if (result == true && mounted) {
      _controller.loadUsers(refresh: true);
    }
  }

  /// 사용자 삭제 다이얼로그
  void _showDeleteDialog(int userId, String userName) {
    showShadDialog(
      context: context,
      builder: (context) => ShadDialog(
        title: const Text('사용자 삭제'),
        description: Text('"$userName" 사용자를 정말로 삭제하시겠습니까?'),
        actions: [
          ShadButton.outline(
            child: const Text('취소'),
            onPressed: () => Navigator.of(context).pop(),
          ),
          ShadButton.destructive(
            child: const Text('삭제'),
            onPressed: () async {
              Navigator.of(context).pop();
              
              await _controller.deleteUser(userId);
              ShadToaster.of(context).show(
                ShadToast(
                  title: const Text('삭제 완료'),
                  description: const Text('사용자가 삭제되었습니다'),
                ),
              );
            },
          ),
        ],
      ),
    );
  }
  
  /// 상태 변경 확인 다이얼로그
  void _showStatusChangeDialog(User user) {
    final newStatus = !user.isActive;
    final statusText = newStatus ? '활성화' : '비활성화';
    
    showShadDialog(
      context: context,
      builder: (context) => ShadDialog(
        title: const Text('사용자 상태 변경'),
        description: Text('"${user.name}" 사용자를 $statusText 하시겠습니까?'),
        actions: [
          ShadButton.outline(
            child: const Text('취소'),
            onPressed: () => Navigator.of(context).pop(),
          ),
          ShadButton(
            child: Text(statusText),
            onPressed: () async {
              Navigator.of(context).pop();
              await _controller.changeUserStatus(user, !user.isActive);
            },
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: ShadcnTheme.background,
      appBar: AppBar(
        title: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              '사용자 관리',
              style: ShadcnTheme.headingH4,
            ),
            Text(
              '시스템 사용자를 관리합니다',
              style: ShadcnTheme.bodySmall,
            ),
          ],
        ),
        backgroundColor: ShadcnTheme.background,
        elevation: 0,
      ),
      body: ListenableBuilder(
        listenable: _controller,
        builder: (context, child) {
          return BaseListScreen(
            headerSection: _buildStatisticsCards(),
            searchBar: _buildSearchBar(),
            actionBar: _buildActionBar(),
            dataTable: _buildDataTable(),
            pagination: _buildPagination(),
            isLoading: _controller.isLoading && _controller.users.isEmpty,
            error: _controller.error,
            onRefresh: () => _controller.loadUsers(refresh: true),
          );
        },
      ),
    );
  }

  Widget _buildStatisticsCards() {
    if (_controller.isLoading) return const SizedBox();
    
    return Row(
      children: [
        _buildStatCard(
          '전체 사용자',
          _controller.total.toString(),
          Icons.people,
          ShadcnTheme.primary,
        ),
        const SizedBox(width: ShadcnTheme.spacing4),
        _buildStatCard(
          '활성 사용자',
          _controller.users.where((u) => u.isActive).length.toString(),
          Icons.check_circle,
          ShadcnTheme.success,
        ),
        const SizedBox(width: ShadcnTheme.spacing4),
        _buildStatCard(
          '비활성 사용자',
          _controller.users.where((u) => !u.isActive).length.toString(),
          Icons.person_off,
          ShadcnTheme.mutedForeground,
        ),
      ],
    );
  }

  Widget _buildSearchBar() {
    return Row(
      children: [
        Expanded(
          child: ShadInputFormField(
            controller: _searchController,
            placeholder: const Text('이름, 이메일로 검색...'),
          ),
        ),
        const SizedBox(width: ShadcnTheme.spacing4),
        ShadButton.outline(
          onPressed: () => _controller.clearFilters(),
          child: const Text('초기화'),
        ),
      ],
    );
  }

  Widget _buildActionBar() {
    return StandardActionBar(
      totalCount: _controller.totalCount,
      leftActions: const [
        Text('사용자 목록', style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold)),
      ],
      rightActions: [
        ShadButton(
          onPressed: _navigateToAdd,
          child: const Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              Icon(Icons.person_add, size: 16),
              SizedBox(width: ShadcnTheme.spacing1),
              Text('사용자 추가'),
            ],
          ),
        ),
      ],
    );
  }

  Widget _buildDataTable() {
    if (_controller.users.isEmpty && !_controller.isLoading) {
      return StandardDataTable(
        columns: _getColumns(),
        rows: const [],
        emptyMessage: '등록된 사용자가 없습니다',
        emptyIcon: Icons.people_outlined,
      );
    }

    return StandardDataTable(
      columns: _getColumns(),
      rows: _buildRows(),
      fixedHeader: true,
      maxHeight: 600,
    );
  }

  List<StandardDataColumn> _getColumns() {
    return [
      StandardDataColumn(label: 'No.', width: 60),
      StandardDataColumn(label: '이름', flex: 1),
      StandardDataColumn(label: '이메일', flex: 2),
      StandardDataColumn(label: '회사', flex: 1),
      StandardDataColumn(label: '권한', width: 80),
      StandardDataColumn(label: '상태', width: 80),
      StandardDataColumn(label: '작업', width: 120),
    ];
  }

  List<Widget> _buildRows() {
    return _controller.users.asMap().entries.map((entry) {
      final index = entry.key;
      final user = entry.value;
      final rowNumber = (_controller.currentPage - 1) * _controller.pageSize + index + 1;

      return StandardDataRow(
        index: index,
        cells: [
          Text(
            rowNumber.toString(),
            style: ShadcnTheme.bodyMedium,
          ),
          Text(
            user.name,
            style: ShadcnTheme.bodyMedium.copyWith(
              fontWeight: FontWeight.w500,
            ),
          ),
          Text(
            user.email,
            style: ShadcnTheme.bodyMedium,
          ),
          Text(
            '-', // Company name not available in current model
            style: ShadcnTheme.bodySmall,
          ),
          _buildUserRoleBadge(user.role),
          _buildStatusChip(user.isActive),
          Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              ShadButton.ghost(
                onPressed: user.id != null ? () => _navigateToEdit(user.id!) : null,
                child: const Icon(Icons.edit, size: 16),
              ),
              const SizedBox(width: ShadcnTheme.spacing1),
              ShadButton.ghost(
                onPressed: () => _showStatusChangeDialog(user),
                child: Icon(
                  user.isActive ? Icons.person_off : Icons.person,
                  size: 16,
                ),
              ),
              const SizedBox(width: ShadcnTheme.spacing1),
              ShadButton.ghost(
                onPressed: user.id != null ? () => _showDeleteDialog(user.id!, user.name) : null,
                child: const Icon(Icons.delete, size: 16),
              ),
            ],
          ),
        ],
      );
    }).toList();
  }

  Widget _buildPagination() {
    if (_controller.totalPages <= 1) return const SizedBox();
    
    return Pagination(
      currentPage: _controller.currentPage,
      totalCount: _controller.total,
      pageSize: _controller.pageSize,
      onPageChanged: (page) => _controller.goToPage(page),
    );
  }

  Widget _buildStatCard(
    String title,
    String value,
    IconData icon,
    Color color,
  ) {
    return Expanded(
      child: ShadCard(
        child: Padding(
          padding: const EdgeInsets.all(ShadcnTheme.spacing4),
          child: Row(
            children: [
              Container(
                padding: const EdgeInsets.all(ShadcnTheme.spacing3),
                decoration: BoxDecoration(
                  color: color.withValues(alpha: 0.1),
                  borderRadius: BorderRadius.circular(ShadcnTheme.radiusLg),
                ),
                child: Icon(
                  icon,
                  color: color,
                  size: 20,
                ),
              ),
              const SizedBox(width: ShadcnTheme.spacing3),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      title,
                      style: ShadcnTheme.bodySmall,
                    ),
                    Text(
                      value,
                      style: ShadcnTheme.headingH6.copyWith(
                        color: color,
                      ),
                    ),
                  ],
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildStatusChip(bool isActive) {
    if (isActive) {
      return ShadBadge.secondary(
        child: const Text('활성'),
      );
    } else {
      return ShadBadge.destructive(
        child: const Text('비활성'),
      );
    }
  }

  // StandardDataRow 임시 정의
}

/// 표준 데이터 행 위젯 (임시)
class StandardDataRow extends StatelessWidget {
  final int index;
  final List<Widget> cells;
  final VoidCallback? onTap;
  final bool selected;

  const StandardDataRow({
    super.key,
    required this.index,
    required this.cells,
    this.onTap,
    this.selected = false,
  });

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: onTap,
      child: Container(
        height: 56,
        padding: const EdgeInsets.symmetric(
          horizontal: ShadcnTheme.spacing4,
          vertical: ShadcnTheme.spacing3,
        ),
        decoration: BoxDecoration(
          color: selected 
              ? ShadcnTheme.primaryLight.withValues(alpha: 0.1)
              : (index.isEven 
                  ? ShadcnTheme.muted.withValues(alpha: 0.3)
                  : null),
          border: const Border(
            bottom: BorderSide(color: ShadcnTheme.border, width: 1),
          ),
        ),
        child: Row(
          children: _buildCellWidgets(),
        ),
      ),
    );
  }

  List<Widget> _buildCellWidgets() {
    return cells.asMap().entries.map((entry) {
      final index = entry.key;
      final cell = entry.value;
      
      // 마지막 셀이 아니면 오른쪽에 간격 추가
      if (index < cells.length - 1) {
        return Expanded(
          child: Padding(
            padding: const EdgeInsets.only(right: ShadcnTheme.spacing2),
            child: cell,
          ),
        );
      } else {
        return cell;
      }
    }).toList();
  }
}