import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:tatlock_ui/core/api/api_client.dart';
import 'package:tatlock_ui/shared/components/data_grid/adapters/core_api_source.dart';
import 'package:tatlock_ui/shared/components/data_grid/data_grid_exports.dart';

/// Simple user data class for display.
class UserData {
  UserData({
    required this.id,
    required this.email,
    required this.name,
    this.avatarUrl,
    required this.createdAt,
    this.lastLogin,
    this.roles = const [],
  });

  factory UserData.fromJson(Map<String, dynamic> json) => UserData(
        id: json['id'] as String,
        email: json['email'] as String,
        name: json['name'] as String,
        avatarUrl: json['avatar_url'] as String?,
        createdAt: DateTime.parse(json['created_at'] as String),
        lastLogin: json['last_login'] != null
            ? DateTime.parse(json['last_login'] as String)
            : null,
        roles: (json['roles'] as List<dynamic>?)?.cast<String>() ?? [],
      );

  final String id;
  final String email;
  final String name;
  final String? avatarUrl;
  final DateTime createdAt;
  final DateTime? lastLogin;
  final List<String> roles;

  bool get isAdmin => roles.any((r) => r.endsWith(':admin'));

  String get initials {
    final parts = name.split(' ');
    if (parts.length >= 2) {
      return '${parts.first[0]}${parts.last[0]}'.toUpperCase();
    }
    return name.substring(0, name.length.clamp(0, 2)).toUpperCase();
  }

  String get lastLoginFormatted {
    if (lastLogin == null) return 'Never';
    final diff = DateTime.now().difference(lastLogin!);
    if (diff.inDays > 30) {
      return '${lastLogin!.day}/${lastLogin!.month}/${lastLogin!.year}';
    }
    if (diff.inDays > 0) return '${diff.inDays}d ago';
    if (diff.inHours > 0) return '${diff.inHours}h ago';
    if (diff.inMinutes > 0) return '${diff.inMinutes}m ago';
    return 'Just now';
  }
}

/// Users list page using the shared DataGrid component.
class UsersListPage extends ConsumerStatefulWidget {
  const UsersListPage({super.key});

  @override
  ConsumerState<UsersListPage> createState() => _UsersListPageState();
}

class _UsersListPageState extends ConsumerState<UsersListPage> {
  late final StateNotifierProvider<DataGridController<UserData>,
      DataGridState<UserData>> _gridProvider;
  bool _isSyncing = false;

  @override
  void initState() {
    super.initState();
    final dio = ref.read(coreApiClientProvider);
    final source = CoreApiDataSource<UserData>(
      dio: dio,
      endpoint: '/auth/users',
      fromJson: UserData.fromJson,
    );

    _gridProvider = dataGridProvider<UserData>(
      source: source,
      config: _buildConfig(),
      idSelector: (u) => u.id,
    );
  }

  Future<void> _syncFromAuthentik() async {
    if (_isSyncing) return;
    setState(() => _isSyncing = true);

    try {
      final dio = ref.read(coreApiClientProvider);
      await dio.post<void>('/auth/users/sync-from-authentik');

      if (!mounted) return;
      ref.read(_gridProvider.notifier).refresh();

      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: const Text('Users synced from Authentik'),
          behavior: SnackBarBehavior.floating,
          duration: const Duration(seconds: 2),
        ),
      );
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text('Sync failed: $e'),
          behavior: SnackBarBehavior.floating,
          duration: const Duration(seconds: 4),
        ),
      );
    } finally {
      if (mounted) setState(() => _isSyncing = false);
    }
  }

  DataGridConfig<UserData> _buildConfig() {
    return DataGridConfig<UserData>(
      columns: [
        DataGridColumn<UserData>(
          header: 'User',
          valueBuilder: (u) => u.name,
          sortable: true,
          searchable: true,
          width: const DataGridColumnWidth.flex(2),
          cellBuilder: (context, u) => _UserCell(user: u),
        ),
        DataGridColumn<UserData>(
          header: 'Roles',
          valueBuilder: (u) => u.roles.join(', '),
          width: const DataGridColumnWidth.flex(1),
          cellBuilder: (context, u) => _RolesCell(roles: u.roles),
        ),
        DataGridColumn<UserData>(
          header: 'Last Login',
          valueBuilder: (u) => u.lastLoginFormatted,
          width: const DataGridColumnWidth.fixed(120),
          alignment: DataGridColumnAlignment.end,
        ),
      ],
      enableSearch: true,
      searchHint: 'Search users...',
      showHeader: true,
      showFooter: true,
    );
  }

  @override
  Widget build(BuildContext context) {
    return DataGrid<UserData>(
      provider: _gridProvider,
      config: _buildConfig(),
      idSelector: (u) => u.id,
      toolbarActions: [
        IconButton(
          icon: const Icon(Icons.refresh),
          tooltip: 'Refresh',
          onPressed: () => ref.read(_gridProvider.notifier).refresh(),
        ),
        const SizedBox(width: 8),
        FilledButton.icon(
          onPressed: _isSyncing ? null : _syncFromAuthentik,
          icon: _isSyncing
              ? const SizedBox(
                  width: 16,
                  height: 16,
                  child: CircularProgressIndicator(strokeWidth: 2),
                )
              : const Icon(Icons.sync),
          label: const Text('Sync from Authentik'),
        ),
      ],
    );
  }
}

class _UserCell extends StatelessWidget {
  const _UserCell({required this.user});

  final UserData user;

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

    return Row(
      children: [
        CircleAvatar(
          radius: 16,
          backgroundColor: colorScheme.primaryContainer,
          backgroundImage:
              user.avatarUrl != null ? NetworkImage(user.avatarUrl!) : null,
          child: user.avatarUrl == null
              ? Text(
                  user.initials,
                  style: TextStyle(
                    fontSize: 12,
                    color: colorScheme.onPrimaryContainer,
                    fontWeight: FontWeight.w500,
                  ),
                )
              : null,
        ),
        const SizedBox(width: 12),
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            mainAxisSize: MainAxisSize.min,
            children: [
              Row(
                children: [
                  Flexible(
                    child: Text(
                      user.name,
                      style: const TextStyle(fontWeight: FontWeight.w500),
                      overflow: TextOverflow.ellipsis,
                    ),
                  ),
                  if (user.isAdmin) ...[
                    const SizedBox(width: 8),
                    Container(
                      padding: const EdgeInsets.symmetric(
                        horizontal: 6,
                        vertical: 2,
                      ),
                      decoration: BoxDecoration(
                        color: colorScheme.primaryContainer,
                        borderRadius: BorderRadius.circular(4),
                      ),
                      child: Text(
                        'Admin',
                        style: TextStyle(
                          fontSize: 10,
                          fontWeight: FontWeight.w500,
                          color: colorScheme.onPrimaryContainer,
                        ),
                      ),
                    ),
                  ],
                ],
              ),
              Text(
                user.email,
                style: TextStyle(
                  fontSize: 12,
                  color: colorScheme.onSurfaceVariant,
                ),
                overflow: TextOverflow.ellipsis,
              ),
            ],
          ),
        ),
      ],
    );
  }
}

class _RolesCell extends StatelessWidget {
  const _RolesCell({required this.roles});

  final List<String> roles;

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

    if (roles.isEmpty) {
      return Text(
        'No roles',
        style: TextStyle(
          fontSize: 12,
          color: colorScheme.outline,
          fontStyle: FontStyle.italic,
        ),
      );
    }

    return Wrap(
      spacing: 4,
      runSpacing: 4,
      children: roles.take(3).map((role) {
        return Container(
          padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
          decoration: BoxDecoration(
            color: colorScheme.surfaceContainerHighest,
            borderRadius: BorderRadius.circular(4),
          ),
          child: Text(
            role.split(':').last,
            style: TextStyle(
              fontSize: 10,
              color: colorScheme.onSurfaceVariant,
            ),
          ),
        );
      }).toList(),
    );
  }
}