import 'package:equatable/equatable.dart';
import 'package:file_picker/file_picker.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flux/core/blocs/session/session_cubit.dart';
import 'package:flux/core/utils/extensions.dart';
import 'package:flux/features/operations/data/operations_repository.dart';
import 'package:flux/features/operations/models/energy_operation_model.dart';
import 'package:flux/features/operations/models/entertainment_operation_model.dart';
import 'package:flux/features/operations/models/fin_operation_model.dart';
import 'package:flux/features/operations/models/operation_file_model.dart';
import 'package:flux/features/operations/models/operation_model.dart';
import 'package:get_it/get_it.dart';
import 'package:collection/collection.dart';
part 'operations_state.dart';

class OperationsCubit extends Cubit<OperationsState> {
  final OperationsRepository _repository = GetIt.I<OperationsRepository>();
  final SessionCubit _sessionCubit = GetIt.I<SessionCubit>();

  OperationsCubit()
    : super(const OperationsState(status: OperationsStatus.initial));

  // --- CARICAMENTO E PAGINAZIONE ---

  Future<void> loadOperations({bool refresh = false}) async {
    // Se stiamo già caricando, evitiamo chiamate doppie
    if (state.status == OperationsStatus.loading) return;

    // Se non è un refresh e abbiamo già raggiunto la fine dei dati, ci fermiamo
    if (!refresh && state.hasReachedMax) return;

    emit(
      state.copyWith(
        status: OperationsStatus.loading,
        errorMessage: null,
        // Se è un refresh, svuotiamo la lista attuale per mostrare lo shimmer/loading
        allOperations: refresh ? [] : state.allOperations,
        hasReachedMax: refresh ? false : state.hasReachedMax,
      ),
    );

    try {
      final currentOffset = refresh ? 0 : state.allOperations.length;
      final companyId = _sessionCubit.state.company?.id;

      if (companyId == null) {
        throw Exception("Company ID non trovato nella sessione");
      }

      final newOperations = await _repository.fetchOperations(
        companyId: companyId,
        offset: currentOffset,
        limit: 50,
        searchTerm: state.query,
        dateRange: state.dateRange,
      );

      // Se ricevi meno record del limite, significa che non ce ne sono altri sul DB
      final bool reachedMax = newOperations.length < 50;

      emit(
        state.copyWith(
          status: OperationsStatus.ready,
          allOperations: refresh
              ? newOperations
              : [...state.allOperations, ...newOperations],
          hasReachedMax: reachedMax,
        ),
      );
    } catch (e) {
      emit(
        state.copyWith(
          status: OperationsStatus.failure,
          errorMessage: "Errore nel caricamento servizi: $e",
        ),
      );
    }
  }

  // --- GESTIONE FILTRI ---

  /// Aggiorna i parametri di ricerca e ricarica da zero
  void updateFilters({String? query, DateTimeRange? range}) {
    emit(
      state.copyWith(
        query: query ?? state.query,
        dateRange: range ?? state.dateRange,
      ),
    );
    loadOperations(refresh: true);
  }

  /// Pulisce tutti i filtri
  void clearFilters() {
    emit(state.copyWith(query: '', dateRange: null));
    loadOperations(refresh: true);
  }

  // --- GESTIONE BOZZA (DRAFT) ---

  /// Inizializza un nuovo servizio o ne carica uno esistente per la modifica
  void initOperationForm({
    OperationModel? existingOperation,
    String? operationId,
  }) async {
    if (existingOperation != null) {
      emit(
        state.copyWith(
          currentOperation: existingOperation,
          status: OperationsStatus.ready,
        ),
      );
    } else if (operationId != null) {
      OperationModel? operationModel = state.allOperations.firstWhereOrNull(
        (s) => s.id == operationId,
      );
      operationModel ??= await _repository.fetchOperationById(operationId);
      emit(
        state.copyWith(
          currentOperation: operationModel,
          status: OperationsStatus.ready,
        ),
      );
    } else {
      // Crea un template vuoto con lo store di default (se disponibile)
      emit(
        state.copyWith(
          currentOperation: OperationModel(
            storeId: _sessionCubit.state.currentStore?.id ?? '',
            number: '', // Sarà compilato dall'utente
            createdAt: DateTime.now(),
            companyId: _sessionCubit.state.company!.id!,
          ),
          status: OperationsStatus.ready,
        ),
      );
    }
  }

  /// Metodo generico per aggiornare i campi base (AL, MNP, Note, ecc.)
  void updateField({
    int? al,
    int? mnp,
    int? nip,
    int? unica,
    int? telepass,
    String? note,
    String? number,
    bool? isBozza,
    bool? resultOk,
    String? customerId,
    String? customerDisplayName,
  }) {
    if (state.currentOperation == null) return;

    final updated = state.currentOperation!.copyWith(
      al: al,
      mnp: mnp,
      nip: nip,
      unica: unica,
      telepass: telepass,
      note: note,
      number: number,
      isBozza: isBozza,
      resultOk: resultOk,
      customerId: customerId,
      customerDisplayName: customerDisplayName,
    );

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

  // --- GESTIONE MODULI COMPLESSI ---

  void updateEnergyOperations(List<EnergyOperationModel> energyList) {
    emit(
      state.copyWith(
        currentOperation: state.currentOperation?.copyWith(
          energyOperations: energyList,
        ),
      ),
    );
  }

  void updateFinOperations(List<FinOperationModel> finList) {
    emit(
      state.copyWith(
        currentOperation: state.currentOperation?.copyWith(
          finOperations: finList,
        ),
      ),
    );
  }

  void updateEntertainmentOperations(
    List<EntertainmentOperationModel> entList,
  ) {
    emit(
      state.copyWith(
        currentOperation: state.currentOperation?.copyWith(
          entertainmentOperations: entList,
        ),
      ),
    );
  }

  // --- PERSISTENZA ---

  Future<void> saveCurrentOperation({
    required bool isBozza,
    bool shouldPop = true,
    List<OperationFileModel>? files,
  }) async {
    if (state.currentOperation == null) return;

    emit(state.copyWith(status: OperationsStatus.saving, errorMessage: null));
    try {
      // 1. Aggiorniamo il flag bozza in base a quale pulsante ha premuto l'utente
      final operationToSave = state.currentOperation!.copyWith(
        isBozza: isBozza,
        files: files,
      );

      // 2. Salvataggio corazzato
      final updatedOperation = await _repository.saveFullOperation(
        operationToSave,
      );

      // 3. Reset e ricaricamento
      emit(
        state.copyWith(
          status: shouldPop
              ? OperationsStatus.saved
              : OperationsStatus.savedNoPop,
          currentOperation: shouldPop ? null : updatedOperation,
        ),
      );
      await loadOperations(refresh: true);
    } catch (e) {
      emit(
        state.copyWith(
          status: OperationsStatus.failure,
          errorMessage: e.toString(),
        ),
      );
    }
  }

  // --- GESTIONE ALLEGATI LOCALI ---

  void addAttachments(List<PlatformFile> files) {
    final newAttachments = files.map((file) {
      return OperationFileModel(
        id: null, // Meglio null se non è su DB
        operationId: state.currentOperation?.id ?? '',
        name: file.name.fileNameWithoutExtension(),
        extension: file.name.fileExtension(),
        storagePath: '',
        fileSize: file.size,
        localBytes: file.bytes,
        createdAt: DateTime.now(),
      );
    }).toList();

    // Creiamo una nuova lista pulita
    final List<OperationFileModel> updatedList = [
      ...(state.currentOperation?.files ?? []),
      ...newAttachments,
    ];

    // Emettiamo lo stato assicurandoci che il OperationModel venga clonato
    if (state.currentOperation != null) {
      emit(
        state.copyWith(
          currentOperation: state.currentOperation!.copyWith(
            files: updatedList,
          ),
        ),
      );
    }
  }

  void removeAttachment(int index) {
    if (state.currentOperation == null) return;

    final updatedList = List<OperationFileModel>.from(
      state.currentOperation!.files,
    );
    updatedList.removeAt(index);

    emit(
      state.copyWith(
        currentOperation: state.currentOperation?.copyWith(files: updatedList),
      ),
    );
  }

  void saveAndCopyFileToCustomer(List<OperationFileModel> selectedFiles) async {
    final currentOperation = state.currentOperation;

    // 1. Check di sicurezza: se non c'è il cliente, non sappiamo dove copiare
    if (currentOperation == null || currentOperation.customerId == null) {
      emit(
        state.copyWith(
          status: OperationsStatus.failure,
          errorMessage:
              "Impossibile copiare: nessun cliente associato alla pratica.",
        ),
      );
      return;
    }

    emit(state.copyWith(status: OperationsStatus.loading));

    try {
      // 2. SALVATAGGIO CORAZZATO
      // Chiamiamo il repo e otteniamo la pratica con TUTTI i file ora dotati di ID e storagePath
      final updatedOperation = await _repository.saveFullOperation(
        currentOperation,
      );

      // 3. COPIA RELAZIONALE
      // Per ogni file che l'utente ha selezionato nella UI, cerchiamo la sua versione
      // "ufficiale" (quella con lo storagePath) nel modello appena tornato dal DB.
      for (var selectedFile in selectedFiles) {
        // Cerchiamo il match nel modello aggiornato
        final persistedFile = updatedOperation.files.firstWhere(
          (f) =>
              f.name == selectedFile.name &&
              f.extension == selectedFile.extension,
          orElse: () => throw Exception(
            "File ${selectedFile.name} non trovato dopo il salvataggio.",
          ),
        );

        // Creiamo il link nel database del cliente
        await _repository.copyFileToCustomer(
          file: persistedFile,
          customerId: currentOperation.customerId!,
        );
      }

      // 4. AGGIORNAMENTO STATO
      // Aggiorniamo il Cubit con il servizio salvato così la UI mostra i file come "Remoti"
      emit(
        state.copyWith(
          status: OperationsStatus.success,
          currentOperation: updatedOperation,
        ),
      );
    } catch (e) {
      emit(
        state.copyWith(
          status: OperationsStatus.failure,
          errorMessage: "Errore durante il salvataggio e copia: $e",
        ),
      );
    }
  }
}