import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:file_picker/file_picker.dart';
import 'package:share_plus/share_plus.dart';
import '../../../../shared/design_system/tokens/color_tokens.dart';
import '../../../../shared/design_system/tokens/spacing_tokens.dart';
import '../../../../core/di/injection_container.dart';
import '../../../../core/utils/logger.dart';
import '../../data/models/backup_model.dart';
import '../../data/models/backup_config_model.dart';
import '../../data/repositories/backup_repository.dart';
import '../bloc/backup_bloc.dart';

/// Page Sauvegarde & Restauration - UnionFlow Mobile
///
/// Page complète de gestion des sauvegardes avec création, restauration,
/// planification et monitoring des sauvegardes système.
class BackupPage extends StatefulWidget {
  const BackupPage({super.key});

  @override
  State<BackupPage> createState() => _BackupPageState();
}

class _BackupPageState extends State<BackupPage>
    with TickerProviderStateMixin {
  late TabController _tabController;
  
  bool _autoBackupEnabled = true;
  String _selectedFrequency = 'Quotidien';
  String _selectedRetention = '30 jours';
  
  List<BackupModel>? _cachedBackups;
  BackupConfigModel? _cachedConfig;
  
  final List<String> _frequencies = ['Horaire', 'Quotidien', 'Hebdomadaire'];
  final List<String> _retentions = ['7 jours', '30 jours', '90 jours', '1 an'];

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 3, vsync: this);
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      create: (_) => sl<BackupBloc>()
        ..add(LoadBackups())
        ..add(LoadBackupConfig()),
      child: BlocConsumer<BackupBloc, BackupState>(
        listener: (context, state) {
          if (state is BackupsLoaded) {
            _cachedBackups = state.backups;
          } else if (state is BackupConfigLoaded) {
            _cachedConfig = state.config;
          }
          if (state is BackupSuccess) {
            ScaffoldMessenger.of(context).showSnackBar(
              SnackBar(
                content: Text(state.message),
                backgroundColor: const Color(0xFF00B894),
                behavior: SnackBarBehavior.floating,
              ),
            );
          } else if (state is BackupError) {
            ScaffoldMessenger.of(context).showSnackBar(
              SnackBar(
                content: Text(state.error),
                backgroundColor: const Color(0xFFD63031),
                behavior: SnackBarBehavior.floating,
              ),
            );
          }
        },
        builder: (context, state) {
          return Scaffold(
            backgroundColor: ColorTokens.background,
            body: Column(
              children: [
                _buildHeader(),
                _buildTabBar(),
                Expanded(
                  child: TabBarView(
                    controller: _tabController,
                    children: [
                      _buildBackupsTab(state),
                      _buildScheduleTab(),
                      _buildRestoreTab(),
                    ],
                  ),
                ),
              ],
            ),
          );
        },
      ),
    );
  }

  /// Header harmonisé
  Widget _buildHeader() {
    return Container(
      margin: const EdgeInsets.all(SpacingTokens.lg),
      padding: const EdgeInsets.all(SpacingTokens.xl),
      decoration: BoxDecoration(
        gradient: const LinearGradient(
          colors: ColorTokens.primaryGradient,
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
        ),
        borderRadius: BorderRadius.circular(SpacingTokens.radiusXl),
        boxShadow: [
          BoxShadow(
            color: ColorTokens.primary.withOpacity(0.3),
            blurRadius: 20,
            offset: const Offset(0, 8),
          ),
        ],
      ),
      child: Column(
        children: [
          Row(
            children: [
              Container(
                padding: const EdgeInsets.all(12),
                decoration: BoxDecoration(
                  color: Colors.white.withOpacity(0.2),
                  borderRadius: BorderRadius.circular(12),
                ),
                child: const Icon(
                  Icons.backup,
                  color: Colors.white,
                  size: 24,
                ),
              ),
              const SizedBox(width: 16),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    const Text(
                      'Sauvegarde & Restauration',
                      style: TextStyle(
                        fontSize: 20,
                        fontWeight: FontWeight.bold,
                        color: Colors.white,
                      ),
                    ),
                    Text(
                      'Gestion des sauvegardes système',
                      style: TextStyle(
                        fontSize: 14,
                        color: Colors.white.withOpacity(0.8),
                      ),
                    ),
                  ],
                ),
              ),
              Container(
                decoration: BoxDecoration(
                  color: Colors.white.withOpacity(0.2),
                  borderRadius: BorderRadius.circular(8),
                ),
                child: IconButton(
                  onPressed: () => _createBackupNow(),
                  icon: const Icon(
                    Icons.save,
                    color: Colors.white,
                  ),
                  tooltip: 'Sauvegarde immédiate',
                ),
              ),
            ],
          ),
          const SizedBox(height: 16),
          Row(
            children: [
              Expanded(
                child: _buildStatCard(
                  'Dernière sauvegarde',
                  _lastBackupDisplay(),
                  Icons.schedule,
                ),
              ),
              const SizedBox(width: 12),
              Expanded(
                child: _buildStatCard(
                  'Taille totale',
                  _totalSizeDisplay(),
                  Icons.storage,
                ),
              ),
              const SizedBox(width: 12),
              Expanded(
                child: _buildStatCard(
                  'Statut',
                  _statusDisplay(),
                  Icons.check_circle,
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }

  String _lastBackupDisplay() {
    if (_cachedConfig?.lastBackup != null) {
      final d = _cachedConfig!.lastBackup!;
      final diff = DateTime.now().difference(d);
      if (diff.inMinutes < 60) return '${diff.inMinutes} min';
      if (diff.inHours < 24) return '${diff.inHours}h';
      if (diff.inDays < 7) return '${diff.inDays} j';
      return '${d.day}/${d.month}/${d.year}';
    }
    if (_cachedBackups != null && _cachedBackups!.isNotEmpty) {
      final sorted = List<BackupModel>.from(_cachedBackups!)
        ..sort((a, b) => (b.createdAt ?? DateTime(0)).compareTo(a.createdAt ?? DateTime(0)));
      final d = sorted.first.createdAt;
      if (d != null) {
        final diff = DateTime.now().difference(d);
        if (diff.inMinutes < 60) return '${diff.inMinutes} min';
        if (diff.inHours < 24) return '${diff.inHours}h';
        return '${diff.inDays} j';
      }
    }
    return '—';
  }

  String _totalSizeDisplay() {
    if (_cachedConfig?.totalSizeFormatted != null && _cachedConfig!.totalSizeFormatted!.isNotEmpty) {
      return _cachedConfig!.totalSizeFormatted!;
    }
    if (_cachedBackups != null && _cachedBackups!.isNotEmpty) {
      int total = 0;
      for (final b in _cachedBackups!) {
        total += b.sizeBytes ?? 0;
      }
      if (total >= 1024 * 1024 * 1024) return '${(total / (1024 * 1024 * 1024)).toStringAsFixed(1)} GB';
      if (total >= 1024 * 1024) return '${(total / (1024 * 1024)).toStringAsFixed(1)} MB';
      if (total >= 1024) return '${(total / 1024).toStringAsFixed(0)} KB';
      return '$total B';
    }
    return '0 B';
  }

  String _statusDisplay() {
    if (_cachedBackups != null && _cachedBackups!.isNotEmpty) {
      final sorted = List<BackupModel>.from(_cachedBackups!)
        ..sort((a, b) => (b.createdAt ?? DateTime(0)).compareTo(a.createdAt ?? DateTime(0)));
      final s = sorted.first.status;
      if (s == 'COMPLETED') return 'OK';
      if (s == 'FAILED') return 'Erreur';
      if (s == 'IN_PROGRESS') return 'En cours';
    }
    return 'OK';
  }

  /// Carte de statistique
  Widget _buildStatCard(String label, String value, IconData icon) {
    return Container(
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: Colors.white.withOpacity(0.15),
        borderRadius: BorderRadius.circular(12),
      ),
      child: Column(
        children: [
          Icon(icon, color: Colors.white, size: 20),
          const SizedBox(height: 4),
          Text(
            value,
            style: const TextStyle(
              fontSize: 14,
              fontWeight: FontWeight.bold,
              color: Colors.white,
            ),
          ),
          Text(
            label,
            style: TextStyle(
              fontSize: 10,
              color: Colors.white.withOpacity(0.8),
            ),
            textAlign: TextAlign.center,
          ),
        ],
      ),
    );
  }

  /// Barre d'onglets
  Widget _buildTabBar() {
    return Container(
      margin: const EdgeInsets.symmetric(horizontal: 12),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(16),
        boxShadow: [
          BoxShadow(
            color: Colors.black.withOpacity(0.05),
            blurRadius: 10,
            offset: const Offset(0, 2),
          ),
        ],
      ),
      child: TabBar(
        controller: _tabController,
        labelColor: const Color(0xFF6C5CE7),
        unselectedLabelColor: Colors.grey[600],
        indicatorColor: const Color(0xFF6C5CE7),
        indicatorWeight: 3,
        labelStyle: const TextStyle(fontWeight: FontWeight.w600, fontSize: 12),
        tabs: const [
          Tab(icon: Icon(Icons.folder, size: 18), text: 'Sauvegardes'),
          Tab(icon: Icon(Icons.schedule, size: 18), text: 'Planification'),
          Tab(icon: Icon(Icons.restore, size: 18), text: 'Restauration'),
        ],
      ),
    );
  }

  /// Onglet sauvegardes
  Widget _buildBackupsTab(BackupState state) {
    return SingleChildScrollView(
      padding: const EdgeInsets.all(12),
      child: Column(
        children: [
          const SizedBox(height: 16),
          state is BackupLoading
              ? const Center(child: CircularProgressIndicator())
              : _buildBackupsList(state is BackupsLoaded ? state.backups : (_cachedBackups ?? [])),
          const SizedBox(height: 80),
        ],
      ),
    );
  }

  /// Liste des sauvegardes
  Widget _buildBackupsList(List<dynamic> backupsData) {
    final backups = backupsData.map((backup) => {
      'id': backup.id?.toString() ?? '',
      'name': backup.name ?? 'Sans nom',
      'date': backup.createdAt?.toString() ?? '',
      'size': backup.sizeFormatted ?? '0 B',
      'type': backup.type ?? 'Manual',
    }).toList();

    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(16),
        boxShadow: [
          BoxShadow(
            color: Colors.black.withOpacity(0.05),
            blurRadius: 10,
            offset: const Offset(0, 2),
          ),
        ],
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              const Icon(Icons.folder, color: Color(0xFF6C5CE7), size: 20),
              const SizedBox(width: 8),
              Text(
                'Sauvegardes disponibles',
                style: TextStyle(
                  fontSize: 16,
                  fontWeight: FontWeight.w600,
                  color: Colors.grey[800],
                ),
              ),
            ],
          ),
          const SizedBox(height: 16),
          ...backups.map((backup) => _buildBackupItem(backup)),
        ],
      ),
    );
  }

  /// Élément de sauvegarde
  Widget _buildBackupItem(Map<String, dynamic> backup) {
    return Container(
      margin: const EdgeInsets.only(bottom: 12),
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: Colors.grey[50],
        borderRadius: BorderRadius.circular(12),
      ),
      child: Row(
        children: [
          Icon(
            backup['type'] == 'Auto' ? Icons.schedule : Icons.touch_app,
            color: backup['type'] == 'Auto' ? Colors.blue : Colors.green,
            size: 20,
          ),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  backup['name']!,
                  style: const TextStyle(
                    fontSize: 14,
                    fontWeight: FontWeight.w600,
                    color: Color(0xFF1F2937),
                  ),
                ),
                Text(
                  '${backup['date']} • ${backup['size']}',
                  style: TextStyle(
                    fontSize: 12,
                    color: Colors.grey[600],
                  ),
                ),
              ],
            ),
          ),
          PopupMenuButton<String>(
            onSelected: (action) => _handleBackupAction(backup, action),
            itemBuilder: (context) => [
              const PopupMenuItem(value: 'restore', child: Text('Restaurer')),
              const PopupMenuItem(value: 'download', child: Text('Télécharger')),
              const PopupMenuItem(value: 'delete', child: Text('Supprimer')),
            ],
            child: const Icon(Icons.more_vert, color: Colors.grey),
          ),
        ],
      ),
    );
  }

  /// Onglet planification
  Widget _buildScheduleTab() {
    return SingleChildScrollView(
      padding: const EdgeInsets.all(12),
      child: Column(
        children: [
          const SizedBox(height: 16),
          _buildScheduleSettings(),
          const SizedBox(height: 80),
        ],
      ),
    );
  }

  /// Paramètres de planification
  Widget _buildScheduleSettings() {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(16),
        boxShadow: [
          BoxShadow(
            color: Colors.black.withOpacity(0.05),
            blurRadius: 10,
            offset: const Offset(0, 2),
          ),
        ],
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              const Icon(Icons.schedule, color: Color(0xFF6C5CE7), size: 20),
              const SizedBox(width: 8),
              Text(
                'Configuration automatique',
                style: TextStyle(
                  fontSize: 16,
                  fontWeight: FontWeight.w600,
                  color: Colors.grey[800],
                ),
              ),
            ],
          ),
          const SizedBox(height: 16),
          _buildSwitchSetting(
            'Sauvegarde automatique',
            'Activer les sauvegardes programmées',
            _autoBackupEnabled,
            (value) => setState(() => _autoBackupEnabled = value),
          ),
          const SizedBox(height: 12),
          _buildDropdownSetting(
            'Fréquence',
            _selectedFrequency,
            _frequencies,
            (value) => setState(() => _selectedFrequency = value!),
          ),
          const SizedBox(height: 12),
          _buildDropdownSetting(
            'Rétention',
            _selectedRetention,
            _retentions,
            (value) => setState(() => _selectedRetention = value!),
          ),
        ],
      ),
    );
  }

  /// Onglet restauration
  Widget _buildRestoreTab() {
    return SingleChildScrollView(
      padding: const EdgeInsets.all(12),
      child: Column(
        children: [
          const SizedBox(height: 16),
          _buildRestoreOptions(),
          const SizedBox(height: 80),
        ],
      ),
    );
  }

  /// Options de restauration
  Widget _buildRestoreOptions() {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(16),
        boxShadow: [
          BoxShadow(
            color: Colors.black.withOpacity(0.05),
            blurRadius: 10,
            offset: const Offset(0, 2),
          ),
        ],
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              const Icon(Icons.restore, color: Color(0xFF6C5CE7), size: 20),
              const SizedBox(width: 8),
              Text(
                'Options de restauration',
                style: TextStyle(
                  fontSize: 16,
                  fontWeight: FontWeight.w600,
                  color: Colors.grey[800],
                ),
              ),
            ],
          ),
          const SizedBox(height: 16),
          _buildActionButton(
            'Restaurer depuis un fichier',
            'Importer une sauvegarde externe',
            Icons.file_upload,
            const Color(0xFF0984E3),
            () => _restoreFromFile(),
          ),
          const SizedBox(height: 12),
          _buildActionButton(
            'Restauration sélective',
            'Restaurer uniquement certaines données',
            Icons.checklist,
            const Color(0xFF00B894),
            () => _selectiveRestore(),
          ),
          const SizedBox(height: 12),
          _buildActionButton(
            'Point de restauration',
            'Créer un point de restauration avant modification',
            Icons.bookmark,
            const Color(0xFFE17055),
            () => _createRestorePoint(),
          ),
        ],
      ),
    );
  }

  // Méthodes de construction des composants
  Widget _buildSwitchSetting(String title, String subtitle, bool value, Function(bool) onChanged) {
    return Row(
      children: [
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(title, style: const TextStyle(fontSize: 14, fontWeight: FontWeight.w600)),
              Text(subtitle, style: TextStyle(fontSize: 12, color: Colors.grey[600])),
            ],
          ),
        ),
        Switch(value: value, onChanged: onChanged, activeColor: const Color(0xFF6C5CE7)),
      ],
    );
  }

  Widget _buildDropdownSetting(String title, String value, List<String> options, Function(String?) onChanged) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(title, style: const TextStyle(fontSize: 14, fontWeight: FontWeight.w600)),
        const SizedBox(height: 8),
        Container(
          padding: const EdgeInsets.symmetric(horizontal: 12),
          decoration: BoxDecoration(
            color: Colors.grey[50],
            borderRadius: BorderRadius.circular(8),
            border: Border.all(color: Colors.grey[300]!),
          ),
          child: DropdownButtonHideUnderline(
            child: DropdownButton<String>(
              value: value,
              isExpanded: true,
              onChanged: onChanged,
              items: options.map((option) => DropdownMenuItem(value: option, child: Text(option))).toList(),
            ),
          ),
        ),
      ],
    );
  }

  Widget _buildActionButton(String title, String subtitle, IconData icon, Color color, VoidCallback onTap) {
    return InkWell(
      onTap: onTap,
      borderRadius: BorderRadius.circular(12),
      child: Container(
        padding: const EdgeInsets.all(12),
        decoration: BoxDecoration(
          color: color.withOpacity(0.05),
          borderRadius: BorderRadius.circular(12),
          border: Border.all(color: color.withOpacity(0.1)),
        ),
        child: Row(
          children: [
            Icon(icon, color: color, size: 20),
            const SizedBox(width: 12),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(title, style: TextStyle(fontSize: 14, fontWeight: FontWeight.w600, color: color)),
                  Text(subtitle, style: TextStyle(fontSize: 12, color: Colors.grey[600])),
                ],
              ),
            ),
            Icon(Icons.arrow_forward_ios, color: Colors.grey[400], size: 16),
          ],
        ),
      ),
    );
  }

  // Méthodes d'action
  void _createBackupNow() {
    context.read<BackupBloc>().add(CreateBackup('Sauvegarde manuelle', description: 'Créée depuis l\'application mobile'));
  }

  void _handleBackupAction(Map<String, dynamic> backup, String action) {
    final backupId = backup['id'];
    if (backupId == null) return;

    if (action == 'restore') {
      context.read<BackupBloc>().add(RestoreBackup(backupId));
    } else if (action == 'delete') {
      context.read<BackupBloc>().add(DeleteBackup(backupId));
    } else if (action == 'download') {
      _downloadBackup(backupId);
    } else {
      _showSuccessSnackBar('Action "$action" exécutée');
    }
  }

  Future<void> _downloadBackup(String backupId) async {
    try {
      final repo = sl<BackupRepository>();
      final b = await repo.getById(backupId);
      if (b.filePath != null && b.filePath!.isNotEmpty) {
        try {
          await Share.share(
            b.filePath!,
            subject: 'Sauvegarde ${b.name ?? backupId}',
          );
          _showSuccessSnackBar('Partage du lien de téléchargement');
        } catch (e, st) {
          AppLogger.error('BackupPage: partage échoué', error: e, stackTrace: st);
          _showSuccessSnackBar('Téléchargement: configurez l\'URL de téléchargement côté backend');
        }
      } else {
        _showSuccessSnackBar('Téléchargement: l\'API ne fournit pas encore de lien (filePath).');
      }
    } catch (e, st) {
      AppLogger.error('BackupPage: téléchargement échoué', error: e, stackTrace: st);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Impossible de récupérer la sauvegarde.'), backgroundColor: Color(0xFFD63031)),
        );
      }
    }
  }

  Future<void> _restoreFromFile() async {
    try {
      final result = await FilePicker.platform.pickFiles(
        type: FileType.any,
        allowMultiple: false,
      );
      if (result == null || result.files.isEmpty) return;
      final path = result.files.single.path;
      if (path != null && path.isNotEmpty) {
        _showSuccessSnackBar('Fichier sélectionné. Restauration depuis fichier à brancher côté API.');
      } else {
        _showSuccessSnackBar('Restauration depuis fichier à brancher côté API.');
      }
    } catch (e, st) {
      AppLogger.error('BackupPage: restauration depuis fichier', error: e, stackTrace: st);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Sélection de fichier impossible.'), backgroundColor: Color(0xFFD63031)),
        );
      }
    }
  }

  Future<void> _selectiveRestore() async {
    try {
      final result = await FilePicker.platform.pickFiles(
        type: FileType.any,
        allowMultiple: true,
      );
      if (result == null || result.files.isEmpty) {
        _showSuccessSnackBar('Restauration sélective: sélectionnez un ou plusieurs fichiers.');
        return;
      }
      final paths = result.files.map((f) => f.path).whereType<String>().toList();
      if (paths.isNotEmpty) {
        _showSuccessSnackBar('Restauration sélective: ${paths.length} fichier(s) (API à brancher).');
      }
    } catch (e, st) {
      AppLogger.error('BackupPage: restauration sélective', error: e, stackTrace: st);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Sélection impossible.'), backgroundColor: Color(0xFFD63031)),
        );
      }
    }
  }

  void _createRestorePoint() {
    context.read<BackupBloc>().add(CreateBackup('Point de restauration', description: 'Point de restauration'));
  }

  void _showSuccessSnackBar(String message) {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text(message), backgroundColor: const Color(0xFF00B894), behavior: SnackBarBehavior.floating),
    );
  }
}