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

class MindMapAdminScreen extends ConsumerStatefulWidget {
  const MindMapAdminScreen({super.key});

  @override
  ConsumerState<MindMapAdminScreen> createState() => _MindMapAdminScreenState();
}

class _MindMapAdminScreenState extends ConsumerState<MindMapAdminScreen> {
  String _searchQuery = '';
  String? _filterProject;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Управление Mind Maps'),
        actions: [
          IconButton(
            icon: const Icon(Icons.refresh),
            onPressed: () => setState(() {}),
            tooltip: 'Обновить',
          ),
        ],
      ),
      body: Column(
        children: [
          _buildSearchBar(),
          _buildFilterBar(),
          Expanded(child: _buildMindMapsList()),
        ],
      ),
    );
  }

  Widget _buildSearchBar() {
    return Padding(
      padding: const EdgeInsets.all(16),
      child: TextField(
        decoration: InputDecoration(
          hintText: 'Поиск mind-карт...',
          prefixIcon: const Icon(Icons.search),
          suffixIcon: _searchQuery.isNotEmpty
              ? IconButton(
                  icon: const Icon(Icons.clear),
                  onPressed: () => setState(() => _searchQuery = ''),
                )
              : null,
          border: OutlineInputBorder(
            borderRadius: BorderRadius.circular(12),
          ),
        ),
        onChanged: (value) => setState(() => _searchQuery = value),
      ),
    );
  }

  Widget _buildFilterBar() {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: Row(
        children: [
          const Icon(Icons.filter_list, color: Colors.grey),
          const SizedBox(width: 8),
          Expanded(
            child: SingleChildScrollView(
              scrollDirection: Axis.horizontal,
              child: Row(
                children: [
                  FilterChip(
                    label: const Text('Все проекты'),
                    selected: _filterProject == null,
                    onSelected: (selected) =>
                        setState(() => _filterProject = null),
                  ),
                  const SizedBox(width: 8),
                  FilterChip(
                    label: const Text('Проект A'),
                    selected: _filterProject == 'project_a',
                    onSelected: (selected) =>
                        setState(() => _filterProject = 'project_a'),
                  ),
                  const SizedBox(width: 8),
                  FilterChip(
                    label: const Text('Проект B'),
                    selected: _filterProject == 'project_b',
                    onSelected: (selected) =>
                        setState(() => _filterProject = 'project_b'),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildMindMapsList() {
    return StreamBuilder<QuerySnapshot>(
      stream: FirebaseFirestore.instance
          .collection('mind_map_nodes')
          .orderBy('createdAt', descending: true)
          .snapshots(),
      builder: (context, snapshot) {
        if (snapshot.hasError) {
          print('Firestore error: ${snapshot.error}');
          return _buildErrorState(snapshot.error);
        }

        if (snapshot.connectionState == ConnectionState.waiting) {
          return const Center(child: CircularProgressIndicator());
        }

        final allDocs = snapshot.data?.docs ?? [];
        print('Total docs from Firestore: ${allDocs.length}');

        // Преобразуем в Map для безопасной работы
        final mindMaps = <Map<String, dynamic>>[];
        for (final doc in allDocs) {
          try {
            final data = doc.data() as Map<String, dynamic>;
            data['_id'] = doc.id;
            mindMaps.add(data);
          } catch (e) {
            print('Error converting doc: $e');
          }
        }

        // Фильтруем по проекту
        final filtered = mindMaps.where((data) {
          final projectId = data['projectId'] ?? 'unknown';
          final title = data['title']?.toString().toLowerCase() ?? '';

          final matchesProject =
              _filterProject == null || projectId == _filterProject;
          final matchesSearch = title.contains(_searchQuery.toLowerCase());

          return matchesProject && matchesSearch;
        }).toList();

        if (filtered.isEmpty) {
          return _buildEmptyState();
        }

        return ListView.builder(
          padding: const EdgeInsets.all(16),
          itemCount: filtered.length,
          itemBuilder: (context, index) {
            final data = filtered[index];
            final id = data['_id'] as String;
            return _buildMindMapCard(id, data);
          },
        );
      },
    );
  }

  Widget _buildMindMapCard(String id, Map<String, dynamic> data) {
    final title = data['title'] ?? 'Без названия';
    final projectId = data['projectId'] ?? 'unknown';
    final createdAt = data['createdAt'] != null
        ? (data['createdAt'] as Timestamp).toDate()
        : DateTime.now();
    final nodeCount = data['nodeCount'] ?? 0;
    final maxLevel = data['maxLevel'] ?? 0;
    final createdBy = data['createdBy'] ?? 'unknown';

    return Card(
      margin: const EdgeInsets.only(bottom: 12),
      child: ExpansionTile(
        leading: const Icon(Icons.account_tree, color: Colors.blue),
        title: Text(
          title,
          style: const TextStyle(fontWeight: FontWeight.bold),
        ),
        subtitle: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text('Проект: $projectId'),
            Text('Создана: ${_formatDate(createdAt)}'),
          ],
        ),
        trailing: PopupMenuButton<String>(
          onSelected: (value) => _handleAction(id, value, data),
          itemBuilder: (context) => [
            const PopupMenuItem(
              value: 'view',
              child: Row(
                children: [
                  Icon(Icons.visibility, size: 20),
                  SizedBox(width: 12),
                  Text('Просмотр'),
                ],
              ),
            ),
            const PopupMenuItem(
              value: 'export',
              child: Row(
                children: [
                  Icon(Icons.download, size: 20),
                  SizedBox(width: 12),
                  Text('Экспорт'),
                ],
              ),
            ),
            const PopupMenuItem(
              value: 'delete',
              child: Row(
                children: [
                  Icon(Icons.delete, color: Colors.red, size: 20),
                  SizedBox(width: 12),
                  Text('Удалить', style: TextStyle(color: Colors.red)),
                ],
              ),
            ),
          ],
        ),
        children: [
          Padding(
            padding: const EdgeInsets.all(16),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                _buildStatRow('Узлов', nodeCount.toString()),
                _buildStatRow('Уровней', maxLevel.toString()),
                _buildStatRow('Автор', createdBy),
                const SizedBox(height: 16),
                Row(
                  children: [
                    Expanded(
                      child: OutlinedButton.icon(
                        onPressed: () => _handleAction(id, 'export', data),
                        icon: const Icon(Icons.download, size: 18),
                        label: const Text('Экспорт JSON'),
                      ),
                    ),
                    const SizedBox(width: 16),
                    Expanded(
                      child: ElevatedButton.icon(
                        onPressed: () => _handleAction(id, 'delete', data),
                        icon: const Icon(Icons.delete, size: 18),
                        label: const Text('Удалить'),
                        style: ElevatedButton.styleFrom(
                          backgroundColor: Colors.red,
                          foregroundColor: Colors.white,
                        ),
                      ),
                    ),
                  ],
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildStatRow(String label, String value) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [
          Text(label, style: TextStyle(color: Colors.grey[600])),
          Text(value, style: const TextStyle(fontWeight: FontWeight.bold)),
        ],
      ),
    );
  }

  Widget _buildEmptyState() {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(Icons.account_tree, size: 80, color: Colors.grey[400]),
          const SizedBox(height: 16),
          Text(
            'Mind-карты не найдены',
            style: TextStyle(fontSize: 18, color: Colors.grey[600]),
          ),
          const SizedBox(height: 8),
          Text(
            'Создайте первую mind-карту',
            style: TextStyle(color: Colors.grey[500]),
          ),
        ],
      ),
    );
  }

  Widget _buildErrorState(dynamic error) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          const Icon(Icons.error_outline, size: 64, color: Colors.red),
          const SizedBox(height: 16),
          Text('Ошибка: $error'),
          const SizedBox(height: 16),
          ElevatedButton(
            onPressed: () => setState(() {}),
            child: const Text('Повторить'),
          ),
        ],
      ),
    );
  }

  Future<void> _handleAction(
      String id, String action, Map<String, dynamic> data) async {
    switch (action) {
      case 'view':
        // TODO: Открыть mind map
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Просмотр в разработке')),
        );
        break;

      case 'export':
        await _exportMindMap(id, data);
        break;

      case 'delete':
        await _confirmDelete(id, data['title'] ?? 'Без названия');
        break;
    }
  }

  Future<void> _exportMindMap(String id, Map<String, dynamic> data) async {
    try {
      final jsonData = {
        'id': id,
        'title': data['title'],
        'projectId': data['projectId'],
        'createdAt': data['createdAt']?.toString(),
        'data': data,
      };

      final jsonStr = const JsonEncoder.withIndent('  ').convert(jsonData);

      // TODO: Сохранить в файл
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('📤 Экспорт: скопируйте JSON из консоли'),
            backgroundColor: Colors.green,
          ),
        );
        print('=== EXPORT JSON ===');
        print(jsonStr);
        print('=== END EXPORT ===');
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('❌ Ошибка экспорта: $e'),
            backgroundColor: Colors.red,
          ),
        );
      }
    }
  }

  Future<void> _confirmDelete(String id, String title) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Удалить mind-карту?'),
        content: Text(
            '"$title" будет удалена навсегда. Это действие нельзя отменить.'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context, false),
            child: const Text('Отмена'),
          ),
          TextButton(
            onPressed: () => Navigator.pop(context, true),
            style: TextButton.styleFrom(foregroundColor: Colors.red),
            child: const Text('Удалить'),
          ),
        ],
      ),
    );

    if (confirmed == true) {
      await _deleteMindMap(id);
    }
  }

  Future<void> _deleteMindMap(String id) async {
    try {
      await FirebaseFirestore.instance
          .collection('mind_map_nodes')
          .doc(id)
          .delete();

      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('✅ Mind-карта удалена'),
            backgroundColor: Colors.green,
          ),
        );
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('❌ Ошибка удаления: $e'),
            backgroundColor: Colors.red,
          ),
        );
      }
    }
  }

  String _formatDate(DateTime date) {
    final now = DateTime.now();
    final diff = now.difference(date);

    if (diff.inMinutes < 1) return 'только что';
    if (diff.inMinutes < 60) return '${diff.inMinutes} мин. назад';
    if (diff.inHours < 24) return '${diff.inHours} ч. назад';
    if (diff.inDays < 7) return '${diff.inDays} дн. назад';

    return '${date.day}.${date.month}.${date.year}';
  }
}