import 'dart:async';
import 'dart:io';

import 'package:file_picker/file_picker.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:equatable/equatable.dart';
import 'package:flux/features/customers/data/customer_repository.dart';
import 'package:flux/features/customers/models/customer_file_model.dart';
import 'package:get_it/get_it.dart';

part 'customer_files_events.dart';
part 'customer_files_state.dart';

class CustomerFilesBloc extends Bloc<CustomerFilesEvent, CustomerFilesState> {
  final CustomerRepository _repository = GetIt.I<CustomerRepository>();
  final String customerId;
  CustomerFilesBloc(this.customerId)
    : super(const CustomerFilesState(status: CustomerFilesStatus.initial)) {
    on<LoadCustomerFilesEvent>(_loadCustomerFiles);
    on<UploadCustomerFileEvent>(_uploadCustomerFile);
    on<UploadMultipleCustomerFilesEvent>(_uploadMultipleCustomerFiles);
    on<DeleteCustomerFilesEvent>(_deleteCustomerFiles);
    on<ToggleCustomerFileSelectionEvent>(_toggleCustomerFileSelection);
  }
  void _loadCustomerFiles(
    LoadCustomerFilesEvent event,
    Emitter<CustomerFilesState> emit,
  ) async {
    await emit.forEach<List<CustomerFileModel>>(
      _repository.getCustomerFilesStream(customerId),
      onData: (customerFiles) => CustomerFilesState(
        status: CustomerFilesStatus.success,
        customerFiles: customerFiles,
      ),
      onError: (error, stackTrace) => CustomerFilesState(
        status: CustomerFilesStatus.failure,
        error: error.toString(),
      ),
    );
  }

  Future<void> _uploadCustomerFile(
    UploadCustomerFileEvent event,
    Emitter<CustomerFilesState> emit,
  ) async {
    emit(state.copyWith(status: CustomerFilesStatus.uploading));
    if (event.pickedFile != null) {
      try {
        await _repository.uploadAndRegisterFile(
          customerId: customerId,
          pickedFile: event.pickedFile!,
        );
        emit(state.copyWith(status: CustomerFilesStatus.success));
      } catch (e) {
        emit(
          state.copyWith(
            status: CustomerFilesStatus.failure,
            error: e.toString(),
          ),
        );
      }
    }
  }

  FutureOr<void> _uploadMultipleCustomerFiles(
    UploadMultipleCustomerFilesEvent event,
    Emitter<CustomerFilesState> emit,
  ) async {
    if (event.files.isEmpty) {
      emit(
        state.copyWith(
          status: CustomerFilesStatus.failure,
          error: "Nessun file selezionato",
        ),
      );
      return;
    }
    emit(state.copyWith(status: CustomerFilesStatus.uploading, error: null));
    try {
      // 2. Creiamo una lista di "Promesse" (Futures) per il repository
      final List<Future<void>> uploadTasks = [];
      for (var file in event.files) {
        // Aggiungiamo il task alla lista, ma NON usiamo await qui dentro!
        uploadTasks.add(
          _repository.uploadAndRegisterFile(
            customerId: customerId,
            pickedFile: file,
          ),
        );
      }
      // 3. ESECUZIONE PARALLELA!
      // Aspettiamo che tutti i file siano caricati contemporaneamente.
      await Future.wait(uploadTasks);
      // 4. GRAN FINALE: Tutto caricato, emettiamo il success!
      emit(state.copyWith(status: CustomerFilesStatus.success));
    } catch (e) {
      // Se anche un solo file fallisce, catturiamo l'errore
      emit(
        state.copyWith(
          status: CustomerFilesStatus.failure,
          error: "Errore durante l'upload multiplo: $e",
        ),
      );
    }
  }

  Future<void> _deleteCustomerFiles(
    DeleteCustomerFilesEvent event,
    Emitter<CustomerFilesState> emit,
  ) async {
    emit(state.copyWith(status: CustomerFilesStatus.loading));
    try {
      await _repository.deleteDocuments(state.selectedFiles);
      emit(
        state.copyWith(status: CustomerFilesStatus.success, selectedFiles: []),
      );
    } catch (e) {
      emit(
        state.copyWith(
          status: CustomerFilesStatus.failure,
          error: e.toString(),
        ),
      );
    }
  }

  void _toggleCustomerFileSelection(
    ToggleCustomerFileSelectionEvent event,
    Emitter<CustomerFilesState> emit,
  ) {
    List<CustomerFileModel> selectedFiles = List.from(state.selectedFiles);
    if (selectedFiles.contains(event.file)) {
      selectedFiles.remove(event.file);
    } else {
      selectedFiles.add(event.file);
    }
    emit(state.copyWith(selectedFiles: selectedFiles));
  }
}