import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:em2rp/models/event_model.dart';
import 'package:em2rp/models/equipment_model.dart';
import 'package:em2rp/services/equipment_service.dart';

class EventPreparationService {
  final FirebaseFirestore _firestore = FirebaseFirestore.instance;
  final EquipmentService _equipmentService = EquipmentService();

  // Collection references
  CollectionReference get _eventsCollection => _firestore.collection('events');
  CollectionReference get _equipmentCollection => _firestore.collection('equipment');

  // === PRÉPARATION ===

   /// Valider un équipement individuel en préparation
  Future<void> validateEquipmentPreparation(String eventId, String equipmentId) async {
    try {
      final event = await _getEvent(eventId);
      if (event == null) {
        throw Exception('Event not found');
      }

      // Mettre à jour le statut de l'équipement dans la liste
      final updatedEquipment = event.assignedEquipment.map((eq) {
        if (eq.equipmentId == equipmentId) {
          return eq.copyWith(isPrepared: true);
        }
        return eq;
      }).toList();

      await _eventsCollection.doc(eventId).update({
        'assignedEquipment': updatedEquipment.map((e) => e.toMap()).toList(),
      });
    } catch (e) {
      print('Error validating equipment preparation: $e');
      rethrow;
    }
  }

  /// Valider tous les équipements en préparation
  Future<void> validateAllPreparation(String eventId) async {
    try {
      final event = await _getEvent(eventId);
      if (event == null) {
        throw Exception('Event not found');
      }

      // Marquer tous les équipements comme préparés
      final updatedEquipment = event.assignedEquipment.map((eq) {
        return eq.copyWith(isPrepared: true);
      }).toList();

      await _eventsCollection.doc(eventId).update({
        'assignedEquipment': updatedEquipment.map((e) => e.toMap()).toList(),
        'preparationStatus': preparationStatusToString(PreparationStatus.completed),
      });

      // Mettre à jour le statut des équipements à "inUse"
      for (var equipment in event.assignedEquipment) {
        await updateEquipmentStatus(equipment.equipmentId, EquipmentStatus.inUse);
      }
    } catch (e) {
      print('Error validating all preparation: $e');
      rethrow;
    }
  }

  /// Finaliser la préparation avec des équipements manquants
  Future<void> completePreparationWithMissing(
    String eventId,
    List<String> missingEquipmentIds,
  ) async {
    try {
      final event = await _getEvent(eventId);
      if (event == null) {
        throw Exception('Event not found');
      }

      // Marquer comme complété avec manquants
      await _eventsCollection.doc(eventId).update({
        'preparationStatus': preparationStatusToString(PreparationStatus.completedWithMissing),
      });

      // Mettre à jour le statut des équipements préparés à "inUse"
      for (var equipment in event.assignedEquipment) {
        if (equipment.isPrepared && !missingEquipmentIds.contains(equipment.equipmentId)) {
          await updateEquipmentStatus(equipment.equipmentId, EquipmentStatus.inUse);
        }
      }
    } catch (e) {
      print('Error completing preparation with missing: $e');
      rethrow;
    }
  }

  // === RETOUR ===


    /// Valider le retour d'un équipement individuel
  Future<void> validateEquipmentReturn(
    String eventId,
    String equipmentId, {
    int? returnedQuantity,
  }) async {
    try {
      final event = await _getEvent(eventId);
      if (event == null) {
        throw Exception('Event not found');
      }

      // Mettre à jour le statut de l'équipement dans la liste
      final updatedEquipment = event.assignedEquipment.map((eq) {
        if (eq.equipmentId == equipmentId) {
          return eq.copyWith(
            isReturned: true,
            returnedQuantity: returnedQuantity,
          );
        }
        return eq;
      }).toList();

      await _eventsCollection.doc(eventId).update({
        'assignedEquipment': updatedEquipment.map((e) => e.toMap()).toList(),
      });

      // Mettre à jour le stock si c'est un consommable
      if (returnedQuantity != null) {
        final equipmentDoc = await _equipmentCollection.doc(equipmentId).get();
        if (equipmentDoc.exists) {
          final equipment = EquipmentModel.fromMap(
            equipmentDoc.data() as Map<String, dynamic>,
            equipmentDoc.id,
          );

          if (equipment.hasQuantity) {
            final currentAvailable = equipment.availableQuantity ?? 0;
            await _equipmentCollection.doc(equipmentId).update({
              'availableQuantity': currentAvailable + returnedQuantity,
            });
          }
        }
      }
    } catch (e) {
      print('Error validating equipment return: $e');
      rethrow;
    }
  }

  /// Valider tous les retours
  Future<void> validateAllReturn(String eventId) async {
    try {
      final event = await _getEvent(eventId);
      if (event == null) {
        throw Exception('Event not found');
      }

      // Marquer tous les équipements comme retournés
      final updatedEquipment = event.assignedEquipment.map((eq) {
        return eq.copyWith(
          isReturned: true,
          returnedQuantity: eq.returnedQuantity ?? eq.quantity,
        );
      }).toList();

      await _eventsCollection.doc(eventId).update({
        'assignedEquipment': updatedEquipment.map((e) => e.toMap()).toList(),
        'returnStatus': returnStatusToString(ReturnStatus.completed),
      });

      // Mettre à jour le statut des équipements à "available" et gérer les stocks
      for (var equipment in updatedEquipment) {
        await updateEquipmentStatus(equipment.equipmentId, EquipmentStatus.available);

        // Restaurer le stock pour les consommables
        final equipmentDoc = await _equipmentCollection.doc(equipment.equipmentId).get();
        if (equipmentDoc.exists) {
          final equipmentData = EquipmentModel.fromMap(
            equipmentDoc.data() as Map<String, dynamic>,
            equipmentDoc.id,
          );

          if (equipmentData.hasQuantity && equipment.returnedQuantity != null) {
            final currentAvailable = equipmentData.availableQuantity ?? 0;
            await _equipmentCollection.doc(equipment.equipmentId).update({
              'availableQuantity': currentAvailable + equipment.returnedQuantity!,
            });
          }
        }
      }
    } catch (e) {
      print('Error validating all return: $e');
      rethrow;
    }
  }

  /// Finaliser le retour avec des équipements manquants
  Future<void> completeReturnWithMissing(
    String eventId,
    List<String> missingEquipmentIds,
  ) async {
    try {
      final event = await _getEvent(eventId);
      if (event == null) {
        throw Exception('Event not found');
      }

      // Marquer comme complété avec manquants
      await _eventsCollection.doc(eventId).update({
        'returnStatus': returnStatusToString(ReturnStatus.completedWithMissing),
      });

      // Mettre à jour le statut des équipements retournés à "available"
      for (var equipment in event.assignedEquipment) {
        if (equipment.isReturned && !missingEquipmentIds.contains(equipment.equipmentId)) {
          await updateEquipmentStatus(equipment.equipmentId, EquipmentStatus.available);

          // Restaurer le stock pour les consommables
          final equipmentDoc = await _equipmentCollection.doc(equipment.equipmentId).get();
          if (equipmentDoc.exists) {
            final equipmentData = EquipmentModel.fromMap(
              equipmentDoc.data() as Map<String, dynamic>,
              equipmentDoc.id,
            );

            if (equipmentData.hasQuantity && equipment.returnedQuantity != null) {
              final currentAvailable = equipmentData.availableQuantity ?? 0;
              await _equipmentCollection.doc(equipment.equipmentId).update({
                'availableQuantity': currentAvailable + equipment.returnedQuantity!,
              });
            }
          }
        } else if (missingEquipmentIds.contains(equipment.equipmentId)) {
          // Marquer comme perdu
          await updateEquipmentStatus(equipment.equipmentId, EquipmentStatus.lost);
        }
      }
    } catch (e) {
      print('Error completing return with missing: $e');
      rethrow;
    }
  }

  // === HELPERS ===

  /// Mettre à jour le statut d'un équipement
  Future<void> updateEquipmentStatus(String equipmentId, EquipmentStatus status) async {
    try {
      await _equipmentCollection.doc(equipmentId).update({
        'status': equipmentStatusToString(status),
        'updatedAt': Timestamp.fromDate(DateTime.now()),
      });
    } catch (e) {
      print('Error updating equipment status: $e');
      rethrow;
    }
  }

  /// Récupérer un événement
  Future<EventModel?> _getEvent(String eventId) async {
    try {
      final doc = await _eventsCollection.doc(eventId).get();
      if (doc.exists) {
        return EventModel.fromMap(doc.data() as Map<String, dynamic>, doc.id);
      }
      return null;
    } catch (e) {
      print('Error getting event: $e');
      rethrow;
    }
  }

  /// Ajouter un équipement à un événement
  Future<void> addEquipmentToEvent(
    String eventId,
    String equipmentId, {
    int quantity = 1,
  }) async {
    try {
      final event = await _getEvent(eventId);
      if (event == null) {
        throw Exception('Event not found');
      }

      // Vérifier que l'équipement n'est pas déjà ajouté
      final alreadyAdded = event.assignedEquipment.any((eq) => eq.equipmentId == equipmentId);
      if (alreadyAdded) {
        throw Exception('Equipment already added to event');
      }

      final newEquipment = EventEquipment(
        equipmentId: equipmentId,
        quantity: quantity,
      );

      final updatedEquipment = [...event.assignedEquipment, newEquipment];

      await _eventsCollection.doc(eventId).update({
        'assignedEquipment': updatedEquipment.map((e) => e.toMap()).toList(),
      });

      // Décrémenter le stock pour les consommables
      final equipmentDoc = await _equipmentCollection.doc(equipmentId).get();
      if (equipmentDoc.exists) {
        final equipmentData = EquipmentModel.fromMap(
          equipmentDoc.data() as Map<String, dynamic>,
          equipmentDoc.id,
        );

        if (equipmentData.hasQuantity) {
          final currentAvailable = equipmentData.availableQuantity ?? 0;
          await _equipmentCollection.doc(equipmentId).update({
            'availableQuantity': currentAvailable - quantity,
          });
        }
      }
    } catch (e) {
      print('Error adding equipment to event: $e');
      rethrow;
    }
  }

  /// Retirer un équipement d'un événement
  Future<void> removeEquipmentFromEvent(String eventId, String equipmentId) async {
    try {
      final event = await _getEvent(eventId);
      if (event == null) {
        throw Exception('Event not found');
      }

      final equipmentToRemove = event.assignedEquipment.firstWhere(
        (eq) => eq.equipmentId == equipmentId,
      );

      final updatedEquipment = event.assignedEquipment
          .where((eq) => eq.equipmentId != equipmentId)
          .toList();

      await _eventsCollection.doc(eventId).update({
        'assignedEquipment': updatedEquipment.map((e) => e.toMap()).toList(),
      });

      // Restaurer le stock pour les consommables
      final equipmentDoc = await _equipmentCollection.doc(equipmentId).get();
      if (equipmentDoc.exists) {
        final equipmentData = EquipmentModel.fromMap(
          equipmentDoc.data() as Map<String, dynamic>,
          equipmentDoc.id,
        );

        if (equipmentData.hasQuantity) {
          final currentAvailable = equipmentData.availableQuantity ?? 0;
          await _equipmentCollection.doc(equipmentId).update({
            'availableQuantity': currentAvailable + equipmentToRemove.quantity,
          });
        }
      }
    } catch (e) {
      print('Error removing equipment from event: $e');
      rethrow;
    }
  }
}