import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:em2rp/models/maintenance_model.dart';
import 'package:em2rp/providers/maintenance_provider.dart';
import 'package:em2rp/providers/equipment_provider.dart';
import 'package:em2rp/views/maintenance_form_page.dart';
import 'package:em2rp/views/widgets/nav/custom_app_bar.dart';
import 'package:em2rp/views/widgets/nav/main_drawer.dart';
import 'package:em2rp/utils/permission_gate.dart';
import 'package:intl/intl.dart';
import 'package:em2rp/utils/colors.dart';

/// Page de gestion des maintenances
class MaintenanceManagementPage extends StatefulWidget {
  const MaintenanceManagementPage({super.key});

  @override
  State<MaintenanceManagementPage> createState() => _MaintenanceManagementPageState();
}

class _MaintenanceManagementPageState extends State<MaintenanceManagementPage> {
  String _filterType = 'all'; // all, upcoming, overdue, completed

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      _loadMaintenances();
    });
  }

  Future<void> _loadMaintenances() async {
    final maintenanceProvider = context.read<MaintenanceProvider>();
    final equipmentProvider = context.read<EquipmentProvider>();

    await Future.wait([
      maintenanceProvider.loadMaintenances(),
      equipmentProvider.ensureLoaded(),
    ]);
  }

  List<MaintenanceModel> _getFilteredMaintenances(List<MaintenanceModel> maintenances) {
    switch (_filterType) {
      case 'upcoming':
        return maintenances.where((m) => !m.isCompleted && !m.isOverdue).toList();
      case 'overdue':
        return maintenances.where((m) => m.isOverdue).toList();
      case 'completed':
        return maintenances.where((m) => m.isCompleted).toList();
      default:
        return maintenances;
    }
  }

  @override
  Widget build(BuildContext context) {
    return PermissionGate(
      requiredPermissions: const ['manage_maintenances'],
      fallback: Scaffold(
        appBar: const CustomAppBar(title: 'Accès refusé'),
        drawer: const MainDrawer(currentPage: '/maintenance_management'),
        body: const Center(
          child: Padding(
            padding: EdgeInsets.all(24.0),
            child: Text(
              'Vous n\'avez pas les permissions nécessaires pour accéder à la gestion des maintenances.',
              textAlign: TextAlign.center,
              style: TextStyle(fontSize: 16),
            ),
          ),
        ),
      ),
      child: Scaffold(
        appBar: const CustomAppBar(
          title: 'Gestion des maintenances',
        ),
        drawer: const MainDrawer(currentPage: '/maintenance_management'),
        body: Consumer<MaintenanceProvider>(
          builder: (context, maintenanceProvider, _) {
            if (maintenanceProvider.isLoading) {
              return const Center(child: CircularProgressIndicator());
            }

            final filteredMaintenances = _getFilteredMaintenances(
              maintenanceProvider.maintenances,
            );

            return Column(
              children: [
                // Filtres
                _buildFilterChips(),

                // Statistiques
                _buildStatsCards(maintenanceProvider),

                // Liste des maintenances
                Expanded(
                  child: filteredMaintenances.isEmpty
                      ? _buildEmptyState()
                      : _buildMaintenanceList(filteredMaintenances),
                ),
              ],
            );
          },
        ),
        floatingActionButton: FloatingActionButton.extended(
          onPressed: () => _navigateToForm(null),
          backgroundColor: AppColors.bleuFonce,
          icon: const Icon(Icons.add),
          label: const Text('Nouvelle maintenance'),
        ),
      ),
    );
  }

  Widget _buildFilterChips() {
    return Container(
      padding: const EdgeInsets.all(16),
      child: SingleChildScrollView(
        scrollDirection: Axis.horizontal,
        child: Row(
          children: [
            _buildFilterChip('Toutes', 'all'),
            const SizedBox(width: 8),
            _buildFilterChip('À venir', 'upcoming'),
            const SizedBox(width: 8),
            _buildFilterChip('En retard', 'overdue'),
            const SizedBox(width: 8),
            _buildFilterChip('Complétées', 'completed'),
          ],
        ),
      ),
    );
  }

  Widget _buildFilterChip(String label, String filterValue) {
    final isSelected = _filterType == filterValue;
    return FilterChip(
      label: Text(label),
      selected: isSelected,
      onSelected: (selected) {
        setState(() {
          _filterType = filterValue;
        });
      },
      selectedColor: AppColors.bleuFonce.withValues(alpha: 0.2),
      checkmarkColor: AppColors.bleuFonce,
    );
  }

  Widget _buildStatsCards(MaintenanceProvider provider) {
    final upcoming = provider.maintenances.where((m) => !m.isCompleted && !m.isOverdue).length;
    final overdue = provider.maintenances.where((m) => m.isOverdue).length;
    final completed = provider.maintenances.where((m) => m.isCompleted).length;

    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: Row(
        children: [
          Expanded(
            child: _buildStatCard(
              'À venir',
              upcoming.toString(),
              Icons.schedule,
              Colors.blue,
            ),
          ),
          const SizedBox(width: 8),
          Expanded(
            child: _buildStatCard(
              'En retard',
              overdue.toString(),
              Icons.warning,
              Colors.orange,
            ),
          ),
          const SizedBox(width: 8),
          Expanded(
            child: _buildStatCard(
              'Complétées',
              completed.toString(),
              Icons.check_circle,
              Colors.green,
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildStatCard(String label, String value, IconData icon, Color color) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(12),
        child: Column(
          children: [
            Icon(icon, color: color, size: 28),
            const SizedBox(height: 4),
            Text(
              value,
              style: TextStyle(
                fontSize: 20,
                fontWeight: FontWeight.bold,
                color: color,
              ),
            ),
            Text(
              label,
              style: const TextStyle(fontSize: 12),
              textAlign: TextAlign.center,
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildEmptyState() {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(Icons.build_outlined, size: 64, color: Colors.grey[400]),
          const SizedBox(height: 16),
          Text(
            'Aucune maintenance',
            style: TextStyle(fontSize: 18, color: Colors.grey[600]),
          ),
          const SizedBox(height: 8),
          Text(
            'Créez votre première maintenance',
            style: TextStyle(color: Colors.grey[500]),
          ),
        ],
      ),
    );
  }

  Widget _buildMaintenanceList(List<MaintenanceModel> maintenances) {
    // Trier par date (les plus récentes/urgentes en premier)
    final sortedMaintenances = List<MaintenanceModel>.from(maintenances)
      ..sort((a, b) {
        if (a.isCompleted && !b.isCompleted) return 1;
        if (!a.isCompleted && b.isCompleted) return -1;
        return a.scheduledDate.compareTo(b.scheduledDate);
      });

    return ListView.builder(
      padding: const EdgeInsets.all(16),
      itemCount: sortedMaintenances.length,
      itemBuilder: (context, index) {
        return _buildMaintenanceCard(sortedMaintenances[index]);
      },
    );
  }

  Widget _buildMaintenanceCard(MaintenanceModel maintenance) {
    final equipmentProvider = context.read<EquipmentProvider>();
    final equipmentNames = maintenance.equipmentIds
        .map((id) => equipmentProvider.allEquipment
            .cast<dynamic>()
            .firstWhere((e) => e.id == id, orElse: () => null)
            ?.name ?? 'Inconnu')
        .toList();

    final typeInfo = _getMaintenanceTypeInfo(maintenance.type);
    final statusInfo = _getStatusInfo(maintenance);

    return Card(
      margin: const EdgeInsets.only(bottom: 12),
      child: InkWell(
        onTap: () => _navigateToForm(maintenance),
        borderRadius: BorderRadius.circular(4),
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              // En-tête
              Row(
                children: [
                  Container(
                    padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                    decoration: BoxDecoration(
                      color: typeInfo.$3.withValues(alpha: 0.2),
                      borderRadius: BorderRadius.circular(4),
                    ),
                    child: Row(
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        Icon(typeInfo.$2, size: 16, color: typeInfo.$3),
                        const SizedBox(width: 4),
                        Text(
                          typeInfo.$1,
                          style: TextStyle(
                            color: typeInfo.$3,
                            fontWeight: FontWeight.bold,
                            fontSize: 12,
                          ),
                        ),
                      ],
                    ),
                  ),
                  const SizedBox(width: 8),
                  Container(
                    padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                    decoration: BoxDecoration(
                      color: statusInfo.$2.withValues(alpha: 0.2),
                      borderRadius: BorderRadius.circular(4),
                    ),
                    child: Text(
                      statusInfo.$1,
                      style: TextStyle(
                        color: statusInfo.$2,
                        fontWeight: FontWeight.bold,
                        fontSize: 12,
                      ),
                    ),
                  ),
                  const Spacer(),
                  IconButton(
                    icon: const Icon(Icons.more_vert),
                    onPressed: () => _showMaintenanceMenu(maintenance),
                  ),
                ],
              ),
              const SizedBox(height: 12),

              // Nom
              Text(
                maintenance.name,
                style: const TextStyle(
                  fontSize: 18,
                  fontWeight: FontWeight.bold,
                ),
              ),
              const SizedBox(height: 8),

              // Description
              if (maintenance.description.isNotEmpty)
                Text(
                  maintenance.description,
                  style: TextStyle(color: Colors.grey[700]),
                  maxLines: 2,
                  overflow: TextOverflow.ellipsis,
                ),
              const SizedBox(height: 12),

              // Équipements
              Wrap(
                spacing: 4,
                runSpacing: 4,
                children: equipmentNames.map((name) {
                  return Chip(
                    label: Text(name, style: const TextStyle(fontSize: 12)),
                    backgroundColor: Colors.grey[200],
                    padding: EdgeInsets.zero,
                    materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
                  );
                }).toList(),
              ),
              const SizedBox(height: 12),

              // Dates
              Row(
                children: [
                  Icon(Icons.event, size: 16, color: Colors.grey[600]),
                  const SizedBox(width: 4),
                  Text(
                    maintenance.isCompleted
                        ? 'Complétée le ${DateFormat('dd/MM/yyyy').format(maintenance.completedDate!)}'
                        : 'Planifiée le ${DateFormat('dd/MM/yyyy').format(maintenance.scheduledDate)}',
                    style: TextStyle(fontSize: 14, color: Colors.grey[700]),
                  ),
                ],
              ),

              // Coût
              if (maintenance.cost != null) ...[
                const SizedBox(height: 8),
                Row(
                  children: [
                    Icon(Icons.euro, size: 16, color: Colors.grey[600]),
                    const SizedBox(width: 4),
                    Text(
                      '${maintenance.cost!.toStringAsFixed(2)} €',
                      style: const TextStyle(fontSize: 14, fontWeight: FontWeight.w500),
                    ),
                  ],
                ),
              ],
            ],
          ),
        ),
      ),
    );
  }

  (String, IconData, Color) _getMaintenanceTypeInfo(MaintenanceType type) {
    switch (type) {
      case MaintenanceType.preventive:
        return ('Préventive', Icons.schedule, Colors.blue);
      case MaintenanceType.corrective:
        return ('Corrective', Icons.build, Colors.orange);
      case MaintenanceType.inspection:
        return ('Inspection', Icons.search, Colors.purple);
    }
  }

  (String, Color) _getStatusInfo(MaintenanceModel maintenance) {
    if (maintenance.isCompleted) {
      return ('Complétée', Colors.green);
    } else if (maintenance.isOverdue) {
      return ('En retard', Colors.red);
    } else {
      return ('À venir', Colors.blue);
    }
  }

  void _showMaintenanceMenu(MaintenanceModel maintenance) {
    showModalBottomSheet(
      context: context,
      builder: (context) {
        return SafeArea(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              if (!maintenance.isCompleted)
                ListTile(
                  leading: const Icon(Icons.check_circle, color: Colors.green),
                  title: const Text('Marquer comme complétée'),
                  onTap: () {
                    Navigator.pop(context);
                    _completeMaintenance(maintenance);
                  },
                ),
              ListTile(
                leading: const Icon(Icons.edit, color: AppColors.bleuFonce),
                title: const Text('Modifier'),
                onTap: () {
                  Navigator.pop(context);
                  _navigateToForm(maintenance);
                },
              ),
              ListTile(
                leading: const Icon(Icons.delete, color: Colors.red),
                title: const Text('Supprimer'),
                onTap: () {
                  Navigator.pop(context);
                  _deleteMaintenance(maintenance);
                },
              ),
            ],
          ),
        );
      },
    );
  }

  Future<void> _completeMaintenance(MaintenanceModel maintenance) async {
    final result = await showDialog<Map<String, dynamic>>(
      context: context,
      builder: (context) => _CompleteMaintenanceDialog(maintenance: maintenance),
    );

    if (result != null && mounted) {
      try {
        await context.read<MaintenanceProvider>().completeMaintenance(
          maintenance.id,
          performedBy: result['performedBy'],
          cost: result['cost'],
        );

        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(
              content: Text('Maintenance marquée comme complétée'),
              backgroundColor: Colors.green,
            ),
          );
          _loadMaintenances();
        }
      } catch (e) {
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(
              content: Text('Erreur: $e'),
              backgroundColor: Colors.red,
            ),
          );
        }
      }
    }
  }

  Future<void> _deleteMaintenance(MaintenanceModel maintenance) async {
    final confirm = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Supprimer la maintenance'),
        content: Text('Êtes-vous sûr de vouloir supprimer "${maintenance.name}" ?'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context, false),
            child: const Text('Annuler'),
          ),
          ElevatedButton(
            onPressed: () => Navigator.pop(context, true),
            style: ElevatedButton.styleFrom(backgroundColor: Colors.red),
            child: const Text('Supprimer'),
          ),
        ],
      ),
    );

    if (confirm == true && mounted) {
      try {
        await context.read<MaintenanceProvider>().deleteMaintenance(maintenance.id);

        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(
              content: Text('Maintenance supprimée'),
              backgroundColor: Colors.green,
            ),
          );
          _loadMaintenances();
        }
      } catch (e) {
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(
              content: Text('Erreur: $e'),
              backgroundColor: Colors.red,
            ),
          );
        }
      }
    }
  }

  Future<void> _navigateToForm(MaintenanceModel? maintenance) async {
    final result = await Navigator.push<bool>(
      context,
      MaterialPageRoute(
        builder: (context) => MaintenanceFormPage(maintenance: maintenance),
      ),
    );

    if (result == true && mounted) {
      _loadMaintenances();
    }
  }
}

/// Dialog pour compléter une maintenance
class _CompleteMaintenanceDialog extends StatefulWidget {
  final MaintenanceModel maintenance;

  const _CompleteMaintenanceDialog({required this.maintenance});

  @override
  State<_CompleteMaintenanceDialog> createState() => _CompleteMaintenanceDialogState();
}

class _CompleteMaintenanceDialogState extends State<_CompleteMaintenanceDialog> {
  final _costController = TextEditingController();
  final _notesController = TextEditingController();

  @override
  void dispose() {
    _costController.dispose();
    _notesController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: const Text('Compléter la maintenance'),
      content: SingleChildScrollView(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            TextField(
              controller: _costController,
              decoration: const InputDecoration(
                labelText: 'Coût (€)',
                hintText: 'Ex: 150.00',
                prefixIcon: Icon(Icons.euro),
              ),
              keyboardType: TextInputType.number,
            ),
            const SizedBox(height: 16),
            TextField(
              controller: _notesController,
              decoration: const InputDecoration(
                labelText: 'Notes (optionnel)',
                hintText: 'Commentaires sur l\'intervention',
                prefixIcon: Icon(Icons.notes),
              ),
              maxLines: 3,
            ),
          ],
        ),
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.pop(context),
          child: const Text('Annuler'),
        ),
        ElevatedButton(
          onPressed: () {
            final cost = double.tryParse(_costController.text);
            Navigator.pop(context, {
              'cost': cost,
              'notes': _notesController.text.trim(),
            });
          },
          style: ElevatedButton.styleFrom(backgroundColor: Colors.green),
          child: const Text('Valider'),
        ),
      ],
    );
  }
}