import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:tatlock_ui/core/api/api_client.dart';
import 'package:tatlock_ui/routing/url_state.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 group data class for display.
class GroupData {
  GroupData({
    required this.id,
    required this.name,
    required this.isSuperuser,
    required this.memberCount,
    this.parentName,
  });

  factory GroupData.fromJson(Map<String, dynamic> json) => GroupData(
        id: json['id'] as String,
        name: json['name'] as String,
        isSuperuser: json['is_superuser'] as bool? ?? false,
        memberCount: json['member_count'] as int? ?? 0,
        parentName: json['parent_name'] as String?,
      );

  final String id;
  final String name;
  final bool isSuperuser;
  final int memberCount;
  final String? parentName;
}

/// Groups list page using the shared DataGrid component.
class GroupsListPage extends ConsumerStatefulWidget {
  const GroupsListPage({super.key, this.routerState});

  /// Router state for URL deep-linking.
  final GoRouterState? routerState;

  @override
  ConsumerState<GroupsListPage> createState() => _GroupsListPageState();
}

class _GroupsListPageState extends ConsumerState<GroupsListPage> {
  late final StateNotifierProvider<DataGridController<GroupData>,
      DataGridState<GroupData>> _gridProvider;
  late PageUrlState _urlState;
  Timer? _urlSyncTimer;
  bool _isSyncing = false;

  @override
  void initState() {
    super.initState();

    // Parse URL state
    _urlState = PageUrlState.fromQueryParams(
      widget.routerState?.uri.queryParameters ?? {},
    );

    // Create provider in initState to ensure stable reference
    final dio = ref.read(coreApiClientProvider);
    final source = CoreApiDataSource<GroupData>(
      dio: dio,
      endpoint: '/auth/groups',
      fromJson: GroupData.fromJson,
    );

    // Initialize grid with URL state
    _gridProvider = dataGridProvider<GroupData>(
      source: source,
      config: _buildConfig(),
      idSelector: (g) => g.id,
      initialSearch: _urlState.search,
      initialSortColumnIndex: _columnIndexForId(_urlState.sortColumn),
      initialSortDescending: _urlState.sortDescending,
    );
  }

  @override
  void dispose() {
    _urlSyncTimer?.cancel();
    super.dispose();
  }

  /// Find column index by column ID.
  int? _columnIndexForId(String? columnId) {
    if (columnId == null) return null;
    final columns = _buildConfig().columns;
    for (var i = 0; i < columns.length; i++) {
      if (columns[i].id == columnId) return i;
    }
    return null;
  }

  /// Get column ID by index.
  String? _columnIdForIndex(int index) {
    final columns = _buildConfig().columns;
    if (index >= 0 && index < columns.length) {
      return columns[index].id;
    }
    return null;
  }

  /// Schedule URL sync with debounce.
  void _scheduleUrlSync() {
    _urlSyncTimer?.cancel();
    _urlSyncTimer = Timer(const Duration(milliseconds: 500), _syncUrlParams);
  }

  /// Sync current state to URL.
  void _syncUrlParams() {
    final state = ref.read(_gridProvider);

    final params = PageUrlState(
      search: state.searchQuery.isEmpty ? null : state.searchQuery,
      sortColumn: state.sortColumnIndex != null
          ? _columnIdForIndex(state.sortColumnIndex!)
          : null,
      sortDescending: state.sortDescending,
    ).toQueryParams();

    updateBrowserUrlParams(params);
  }

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

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

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

      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: const Text('Groups 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<GroupData> _buildConfig() {
    return DataGridConfig<GroupData>(
      columns: [
        DataGridColumn<GroupData>(
          id: 'name',
          header: 'Name',
          valueBuilder: (g) => g.name,
          sortable: true,
          searchable: true,
          width: const DataGridColumnWidth.flex(2),
        ),
        DataGridColumn<GroupData>(
          id: 'members',
          header: 'Members',
          valueBuilder: (g) => g.memberCount.toString(),
          width: const DataGridColumnWidth.fixed(100),
          alignment: DataGridColumnAlignment.end,
        ),
        DataGridColumn<GroupData>(
          id: 'type',
          header: 'Type',
          valueBuilder: (g) => g.isSuperuser ? 'Superuser' : 'Standard',
          cellBuilder: (context, g) => _GroupTypeBadge(isSuperuser: g.isSuperuser),
          width: const DataGridColumnWidth.fixed(120),
        ),
        DataGridColumn<GroupData>(
          id: 'parent',
          header: 'Parent',
          valueBuilder: (g) => g.parentName ?? '-',
          width: const DataGridColumnWidth.flex(1),
        ),
      ],
      enableSearch: true,
      searchHint: 'Search groups...',
      showHeader: true,
      showFooter: true,
    );
  }

  @override
  Widget build(BuildContext context) {
    // Listen for grid state changes to sync URL
    ref.listen(_gridProvider, (previous, next) {
      if (previous?.searchQuery != next.searchQuery ||
          previous?.sortColumnIndex != next.sortColumnIndex ||
          previous?.sortDescending != next.sortDescending) {
        _scheduleUrlSync();
      }
    });

    return DataGrid<GroupData>(
      provider: _gridProvider,
      config: _buildConfig(),
      idSelector: (g) => g.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 _GroupTypeBadge extends StatelessWidget {
  const _GroupTypeBadge({required this.isSuperuser});

  final bool isSuperuser;

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

    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
      decoration: BoxDecoration(
        color: isSuperuser
            ? colorScheme.primaryContainer
            : colorScheme.surfaceContainerHighest,
        borderRadius: BorderRadius.circular(4),
      ),
      child: Text(
        isSuperuser ? 'Superuser' : 'Standard',
        style: TextStyle(
          fontSize: 12,
          fontWeight: FontWeight.w500,
          color: isSuperuser
              ? colorScheme.onPrimaryContainer
              : colorScheme.onSurfaceVariant,
        ),
      ),
    );
  }
}