import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:firebase_auth/firebase_auth.dart';
import '../providers/mind_maps_provider.dart';
import '../models/mindmap_model.dart';
import '../core/admin_access_service.dart';
import 'mind_map_viewer_screen.dart';
import 'mind_map_editor_screen.dart';
import 'mind_map_interactive_screen.dart';

class MindMapScreen extends ConsumerWidget {
  const MindMapScreen({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final mindMapsAsync = ref.watch(mindMapsProvider);
    final isAdmin = ref.watch(isAdminProvider);
    final currentUserEmail = FirebaseAuth.instance.currentUser?.email ?? '';

    return Scaffold(
      appBar: AppBar(
        title: const Text('Mind Maps'),
        actions: [
          if (isAdmin)
            IconButton(
              icon: const Icon(Icons.admin_panel_settings),
              onPressed: () => _showAdminOptions(context),
              tooltip: 'Админ панель',
            ),
        ],
      ),
      body: mindMapsAsync.when(
        data: (mindMaps) =>
            _buildContent(context, mindMaps, isAdmin, currentUserEmail, ref),
        loading: () => const Center(child: CircularProgressIndicator()),
        error: (error, stack) => Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              const Icon(Icons.error_outline, size: 48, color: Colors.red),
              const SizedBox(height: 16),
              Text('Ошибка: $error'),
              const SizedBox(height: 16),
              ElevatedButton(
                onPressed: () => ref.invalidate(mindMapsProvider),
                child: const Text('Повторить'),
              ),
            ],
          ),
        ),
      ),
      floatingActionButton: FloatingActionButton.extended(
        onPressed: () => _showCreateOptions(context, ref),
        icon: const Icon(Icons.add),
        label: const Text('Создать'),
      ),
    );
  }

  Widget _buildContent(
    BuildContext context,
    List<MindMapModel> mindMaps,
    bool isAdmin,
    String currentUserEmail,
    WidgetRef ref,
  ) {
    // Разделяем на основные и личные
    final mainMaps = mindMaps.where((m) => m.isMain).toList();
    final personalMaps = mindMaps.where((m) => !m.isMain).toList();

    if (mindMaps.isEmpty) {
      return _buildEmptyState(context, ref);
    }

    return ListView(
      padding: const EdgeInsets.all(16),
      children: [
        // Основные карты
        if (mainMaps.isNotEmpty) ...[
          _buildSectionHeader('Основные', Icons.star, Colors.amber),
          ...mainMaps.map((map) =>
              _buildMindMapCard(context, map, isAdmin, currentUserEmail, ref)),
          const SizedBox(height: 16),
        ],

        // Личные карты
        if (personalMaps.isNotEmpty) ...[
          _buildSectionHeader('Личные', Icons.person, Colors.blue),
          ...personalMaps.map((map) =>
              _buildMindMapCard(context, map, isAdmin, currentUserEmail, ref)),
        ],
      ],
    );
  }

  Widget _buildSectionHeader(String title, IconData icon, Color color) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 12),
      child: Row(
        children: [
          Icon(icon, color: color, size: 24),
          const SizedBox(width: 8),
          Text(
            title,
            style: const TextStyle(
              fontSize: 18,
              fontWeight: FontWeight.bold,
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildMindMapCard(
    BuildContext context,
    MindMapModel mindMap,
    bool isAdmin,
    String currentUserEmail,
    WidgetRef ref,
  ) {
    final isOwner = mindMap.ownerEmail == currentUserEmail;
    final canDelete = isAdmin || isOwner;
    final canEdit = isAdmin || isOwner;

    return Card(
      margin: const EdgeInsets.only(bottom: 12),
      child: ListTile(
        leading: CircleAvatar(
          backgroundColor: mindMap.isMain ? Colors.amber : Colors.blue,
          child: Icon(
            mindMap.isMain ? Icons.star : Icons.account_tree,
            color: Colors.white,
          ),
        ),
        title: Text(
          mindMap.title,
          style: const TextStyle(fontWeight: FontWeight.bold),
        ),
        subtitle: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            if (mindMap.description.isNotEmpty)
              Text(mindMap.description,
                  maxLines: 1, overflow: TextOverflow.ellipsis),
            const SizedBox(height: 4),
            Text('Владелец: ${mindMap.ownerEmail}'),
            Text(
                '${mindMap.nodeCount} узлов • ${_formatDate(mindMap.createdAt)}'),
          ],
        ),
        trailing: PopupMenuButton<String>(
          onSelected: (value) => _handleAction(context, value, mindMap, ref),
          itemBuilder: (context) => [
            PopupMenuItem(
              value: 'view',
              child: Row(
                children: [
                  const Icon(Icons.visibility, size: 20),
                  const SizedBox(width: 12),
                  const Text('Открыть'),
                ],
              ),
            ),
            if (canEdit)
              PopupMenuItem(
                value: 'edit',
                child: Row(
                  children: [
                    const Icon(Icons.edit, size: 20),
                    const SizedBox(width: 12),
                    const Text('Редактировать'),
                  ],
                ),
              ),
            if (canDelete)
              PopupMenuItem(
                value: 'delete',
                child: Row(
                  children: [
                    const Icon(Icons.delete, color: Colors.red, size: 20),
                    const SizedBox(width: 12),
                    const Text('Удалить', style: TextStyle(color: Colors.red)),
                  ],
                ),
              ),
          ],
        ),
        onTap: () => _openMindMap(context, mindMap),
      ),
    );
  }

  Widget _buildEmptyState(BuildContext context, WidgetRef ref) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(Icons.account_tree, size: 100, color: Colors.grey[400]),
          const SizedBox(height: 24),
          Text(
            'Нет mind карт',
            style: TextStyle(fontSize: 20, color: Colors.grey[600]),
          ),
          const SizedBox(height: 8),
          Text(
            'Создайте первую карту вручную или с помощью AI',
            textAlign: TextAlign.center,
            style: TextStyle(color: Colors.grey[500]),
          ),
          const SizedBox(height: 32),
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              ElevatedButton.icon(
                onPressed: () => _showCreateManualDialog(context, ref),
                icon: const Icon(Icons.add),
                label: const Text('Вручную'),
              ),
              const SizedBox(width: 16),
              FilledButton.icon(
                onPressed: () => _showCreateAIDialog(context, ref),
                icon: const Icon(Icons.auto_awesome),
                label: const Text('AI Генерация'),
              ),
            ],
          ),
        ],
      ),
    );
  }

  void _showCreateOptions(BuildContext context, WidgetRef ref) {
    showModalBottomSheet(
      context: context,
      builder: (context) => SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            ListTile(
              leading: const Icon(Icons.add, color: Colors.blue),
              title: const Text('Создать вручную'),
              subtitle: const Text('Пустая mind map'),
              onTap: () {
                Navigator.pop(context);
                _showCreateManualDialog(context, ref);
              },
            ),
            ListTile(
              leading: const Icon(Icons.auto_awesome, color: Colors.purple),
              title: const Text('AI Генерация'),
              subtitle: const Text('С помощью DeepSeek'),
              onTap: () {
                Navigator.pop(context);
                _showCreateAIDialog(context, ref);
              },
            ),
          ],
        ),
      ),
    );
  }

  void _showCreateManualDialog(BuildContext context, WidgetRef ref) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => const MindMapEditorScreen(),
      ),
    );
  }

  void _showCreateAIDialog(BuildContext context, WidgetRef ref) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => const MindMapEditorScreen(),
      ),
    );
  }

  void _handleAction(
    BuildContext context,
    String action,
    MindMapModel mindMap,
    WidgetRef ref,
  ) {
    switch (action) {
      case 'view':
        _openMindMap(context, mindMap);
        break;
      case 'edit':
        _editMindMap(context, mindMap, ref);
        break;
      case 'delete':
        _confirmDelete(context, mindMap, ref);
        break;
    }
  }

  void _openMindMap(BuildContext context, MindMapModel mindMap) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => MindMapInteractiveScreen(mindMap: mindMap),
      ),
    );
  }

  void _editMindMap(BuildContext context, MindMapModel mindMap, WidgetRef ref) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => MindMapEditorScreen(mindMap: mindMap),
      ),
    );
  }

  void _confirmDelete(
      BuildContext context, MindMapModel mindMap, WidgetRef ref) {
    showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Удалить mind map?'),
        content: Text(
            '"${mindMap.title}" будет удалена навсегда. Это действие нельзя отменить.'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context),
            child: const Text('Отмена'),
          ),
          TextButton(
            onPressed: () async {
              try {
                await ref
                    .read(mindMapsNotifierProvider.notifier)
                    .deleteMindMap(mindMap.id, mindMap.ownerEmail);

                if (context.mounted) {
                  Navigator.pop(context);
                  ScaffoldMessenger.of(context).showSnackBar(
                    const SnackBar(
                      content: Text('✅ Mind map удалена'),
                      backgroundColor: Colors.green,
                    ),
                  );
                }
              } catch (e) {
                if (context.mounted) {
                  Navigator.pop(context);
                  ScaffoldMessenger.of(context).showSnackBar(
                    SnackBar(
                      content: Text('❌ Ошибка: $e'),
                      backgroundColor: Colors.red,
                    ),
                  );
                }
              }
            },
            style: TextButton.styleFrom(foregroundColor: Colors.red),
            child: const Text('Удалить'),
          ),
        ],
      ),
    );
  }

  void _showAdminOptions(BuildContext context) {
    // TODO: Открыть админ панель
    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(content: Text('Админ панель в разработке')),
    );
  }

  String _formatDate(DateTime date) {
    return '${date.day.toString().padLeft(2, '0')}.'
        '${date.month.toString().padLeft(2, '0')}.'
        '${date.year}';
  }
}