import 'package:equatable/equatable.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flux/core/blocs/session/session_cubit.dart';
import 'package:flux/features/operations/data/operations_repository.dart';
import 'package:flux/features/operations/models/operation_model.dart';
import 'package:get_it/get_it.dart';
import 'package:uuid/uuid.dart';

part 'operation_form_state.dart';

class OperationFormCubit extends Cubit<OperationFormState> {
  final OperationsRepository _repository = GetIt.I<OperationsRepository>();
  final SessionCubit _sessionCubit = GetIt.I<SessionCubit>();
  final Uuid _uuid = const Uuid();

  OperationFormCubit()
    : super(
        OperationFormState(
          // Inizializziamo con un modello vuoto di sicurezza
          operation: OperationModel(
            storeId: '',
            companyId: '',
            reference: '',
            status: OperationStatus.draft,
            createdAt: DateTime.now(),
          ),
        ),
      );

  Future<void> initForm({
    OperationModel? existingOperation,
    String? operationId,
  }) async {
    emit(state.copyWith(status: OperationFormStatus.loading));

    try {
      if (existingOperation != null) {
        emit(
          state.copyWith(
            operation: existingOperation,
            status: OperationFormStatus.ready,
          ),
        );
      } else if (operationId != null) {
        // Avendo separato i cubit, se ci passano solo l'ID lo scarichiamo dal DB
        final operation = await _repository.fetchOperationById(operationId);
        emit(
          state.copyWith(
            operation: operation,
            status: OperationFormStatus.ready,
          ),
        );
      } else {
        // NUOVA PRATICA: Creiamo un nuovo Batch UUID
        emit(
          state.copyWith(
            operation: OperationModel(
              storeId: _sessionCubit.state.currentStore?.id ?? '',
              reference: '',
              createdAt: DateTime.now(),
              companyId: _sessionCubit.state.company!.id!,
              status: OperationStatus.draft,
              batchUuid: _uuid.v4(),
            ),
            status: OperationFormStatus.ready,
          ),
        );
      }
    } catch (e) {
      emit(
        state.copyWith(
          status: OperationFormStatus.failure,
          errorMessage: "Errore inizializzazione form: $e",
        ),
      );
    }
  }

  // --- LOGICA BATCH ---

  void _prepareNextOperationInBatch() {
    final current = state.operation;

    emit(
      state.copyWith(
        status: OperationFormStatus.ready, // Torna ready per il nuovo form
        operation: OperationModel(
          companyId: current.companyId,
          storeId: current.storeId,
          storeDisplayName: current.storeDisplayName,
          batchUuid: current.batchUuid, // MANTIENE IL COLLEGAMENTO
          customerId: current.customerId, // MANTIENE IL CLIENTE
          customerDisplayName: current.customerDisplayName,
          status: OperationStatus.draft,
          createdAt: DateTime.now(),
        ),
      ),
    );
  }

  // --- SALVATAGGIO ---

  Future<void> saveOperation({
    required OperationStatus targetStatus,
    required bool keepAdding,
  }) async {
    emit(
      state.copyWith(status: OperationFormStatus.saving, errorMessage: null),
    );

    try {
      final operationToSave = state.operation.copyWith(status: targetStatus);
      final savedOperation = await _repository.saveFullOperation(
        operation: operationToSave,
      );

      if (keepAdding) {
        // Salviamo nella "memoria" del batch le pratiche create finora
        final updatedBatchList = List<OperationModel>.from(
          state.savedBatchOperations,
        )..add(savedOperation);

        emit(
          state.copyWith(
            status: OperationFormStatus.successAndAddAnother,
            savedBatchOperations: updatedBatchList,
          ),
        );

        // Pulisce i campi per la prossima operazione
        _prepareNextOperationInBatch();
      } else {
        emit(
          state.copyWith(
            status: OperationFormStatus.success,
            operation: savedOperation, // Aggiorniamo con l'ID restituito dal DB
          ),
        );
      }
    } catch (e) {
      emit(
        state.copyWith(
          status: OperationFormStatus.failure,
          errorMessage: e.toString(),
        ),
      );
    }
  }

  Future<String?> saveOperationDraft() async {
    try {
      final operationToSave = state.operation;
      if (operationToSave.customerId == null ||
          operationToSave.customerId!.isEmpty) {
        throw Exception('Seleziona un cliente prima di poter usare il QR');
      }
      final savedOperation = await _repository.saveFullOperation(
        operation: operationToSave,
      );
      emit(
        state.copyWith(
          operation: savedOperation,
          status: OperationFormStatus.ready,
        ),
      );
      return savedOperation.id;
    } catch (e) {
      emit(
        state.copyWith(
          status: OperationFormStatus.failure,
          errorMessage: e.toString(),
        ),
      );
      return null;
    }
  }

  // --- GESTIONE DEI CAMPI IN TEMPO REALE ---

  void updateFields({
    String? customerId,
    String? customerDisplayName,
    String? reference,
    String? note,
    String? type,
    String? providerId,
    String? providerDisplayName,
    String? subtype,
    String? description,
    DateTime? expirationDate,
    int? quantity,
    String? modelId,
    String? modelDisplayName,
    String? staffId,
    String? staffDisplayName,
    OperationStatus? status,

    bool clearProvider = false,
    bool clearType = false,
    bool clearSubtype = false,
    bool clearDescription = false,
    bool clearExpiration = false,
    bool clearQuantity = false,
    bool clearModel = false,
  }) {
    final current = state.operation;

    int? newQuantity;
    if (clearQuantity) newQuantity = 1;
    if (quantity != null && quantity <= 0) newQuantity = 0;
    if (quantity != null && quantity > 0) newQuantity = quantity;

    final updated = current.copyWith(
      customerId:
          customerId ??
          current.customerId, // Se non passo customerId, tengo il vecchio
      customerDisplayName: customerDisplayName ?? current.customerDisplayName,
      reference: reference ?? current.reference,
      note: note ?? current.note,
      providerId: clearProvider ? null : (providerId ?? current.providerId),
      providerDisplayName: clearProvider
          ? null
          : (providerDisplayName ?? current.providerDisplayName),
      quantity: newQuantity ?? current.quantity,
      type: clearType ? null : (type ?? current.type),
      description: clearDescription
          ? null
          : (description ?? current.description),
      subtype: clearSubtype ? null : (subtype ?? current.subtype),
      expirationDate: clearExpiration
          ? null
          : (expirationDate ?? current.expirationDate),
      modelId: clearModel ? null : (modelId ?? current.modelId),
      modelDisplayName: clearModel
          ? null
          : (modelDisplayName ?? current.modelDisplayName),
      staffId: staffId ?? current.staffId,
      staffDisplayName: staffDisplayName ?? current.staffDisplayName,
      status: status ?? current.status,
    );

    emit(state.copyWith(operation: updated));
  }

  // --- UTILS ---

  void setTypeWithSmartDefault(String type) {
    DateTime? defaultDate;
    final now = DateTime.now();

    if (type == 'Energy') {
      defaultDate = DateTime(now.year, now.month + 24, now.day);
    }
    if (type == 'Fin') {
      defaultDate = DateTime(now.year, now.month + 30, now.day);
    }
    if (type == 'Entertainment') {
      defaultDate = DateTime(now.year, now.month + 12, now.day);
    }

    updateFields(
      type: type,
      expirationDate: defaultDate,
      clearProvider: true,
      clearSubtype: true,
      clearModel: true,
      clearQuantity: true,
    );
  }
}