apskel-pos-flutter-v2/lib/infrastructure/printer/repositories/printer_repository.dart

import 'dart:async';
import 'dart:developer';

import 'package:dartz/dartz.dart' hide Order;
import 'package:firebase_crashlytics/firebase_crashlytics.dart';
import 'package:flutter_esc_pos_network/flutter_esc_pos_network.dart';
import 'package:injectable/injectable.dart' hide Order;
import 'package:permission_handler/permission_handler.dart';
import 'package:print_bluetooth_thermal/print_bluetooth_thermal.dart';
import 'package:synchronized/synchronized.dart';

import '../../../common/extension/extension.dart';
import '../../../domain/order/order.dart';
import '../../../domain/outlet/outlet.dart';
import '../../../domain/printer/printer.dart';
import '../../../presentation/components/print/print_ui.dart';
import '../../auth/datasources/local_data_provider.dart';
import '../../outlet/datasources/local_data_provider.dart';
import '../datasource/local_data_provider.dart';
import '../printer_dtos.dart';

@LazySingleton(as: IPrinterRepository)
class PrinterRepository implements IPrinterRepository {
  final PrinterLocalDataProvider _localDataProvider;
  final OutletLocalDatasource _outletLocalDatasource;
  final AuthLocalDataProvider _authLocalDataProvider;
  final _logName = 'PrinterRepository';

  PrinterRepository(
    this._localDataProvider,
    this._outletLocalDatasource,
    this._authLocalDataProvider,
  );

  /// Seluruh cetakan Bluetooth berbagi satu lock: radionya cuma satu, jadi
  /// lock per alamat tidak menahan dua printer Bluetooth yang berbeda.
  final Lock _bluetoothLock = Lock();

  /// Menjaga satu job cetak selesai sebelum job berikutnya mulai, supaya
  /// tiket dua order tidak saling menyelip.
  final Lock _jobLock = Lock();

  String? _connectedMac;

  @override
  Future<Either<PrinterFailure, bool>> connectBluetooth(String macAddress) {
    // Memakai jalur yang sama dengan mencetak: retry, penutupan socket basi,
    // dan pencatatan `_connectedMac`. Versi sebelumnya mengembalikan sukses
    // begitu ADA koneksi, tanpa memeriksa apakah itu printer yang diminta —
    // menyambungkan printer B saat A tersambung akan tetap "berhasil".
    return _bluetoothLock.synchronized(
      () => _ensureBluetoothConnected(macAddress),
    );
  }

  @override
  Future<Either<PrinterFailure, bool>> disconectBluetooth() async {
    try {
      bool result = await PrintBluetoothThermal.disconnect;
      _connectedMac = null;
      log("Bluetooth printer disconnected: $result", name: _logName);
      return right(result);
    } catch (e) {
      _connectedMac = null;
      log("Error disconnecting Bluetooth printer", error: e, name: _logName);
      return left(
        const PrinterFailure.dynamicErrorMessage(
          'Error disconnecting Bluetooth printer',
        ),
      );
    }
  }

  @override
  Future<Either<PrinterFailure, List<BluetoothInfo>>>
  getPairedBluetoothDevices() async {
    try {
      final result = await PrintBluetoothThermal.pairedBluetooths;

      log("Paired Bluetooth devices: $result", name: _logName);

      return right(result);
    } catch (e) {
      log("Error getting paired Bluetooth devices", name: _logName, error: e);
      return left(
        const PrinterFailure.dynamicErrorMessage(
          'Error getting paired Bluetooth devices',
        ),
      );
    }
  }

  @override
  Future<Either<PrinterFailure, bool>> isBluetoothEnabled() async {
    try {
      final result = await PrintBluetoothThermal.bluetoothEnabled;

      return right(result);
    } catch (e) {
      log("Error checking Bluetooth status", name: _logName, error: e);
      return left(
        const PrinterFailure.dynamicErrorMessage(
          'Error checking Bluetooth status',
        ),
      );
    }
  }

  @override
  Future<Either<PrinterFailure, Unit>> createPrinter(Printer printer) async {
    try {
      final result = await _localDataProvider.createPrinter(
        PrinterDto.fromDomain(printer),
      );

      if (result.hasError) {
        return left(result.error!);
      }

      return right(unit);
    } catch (e) {
      log('createPrinterError', name: _logName, error: e);
      return left(const PrinterFailure.unexpectedError());
    }
  }

  @override
  Future<Either<PrinterFailure, Unit>> deletePrinter(int id) async {
    try {
      final result = await _localDataProvider.deletePrinter(id);

      if (result.hasError) {
        return left(result.error!);
      }

      return right(unit);
    } catch (e) {
      log('deletePrinterError', name: _logName, error: e);
      return left(const PrinterFailure.unexpectedError());
    }
  }

  @override
  Future<Either<PrinterFailure, Printer>> getPrinterByCode(String code) async {
    try {
      final result = await _localDataProvider.findPrinterByCode(code);

      if (result.hasError) {
        return left(result.error!);
      }

      final printer = result.data!.toDomain();

      return right(printer);
    } catch (e) {
      log('getPrinterByCodeError', name: _logName, error: e);
      return left(const PrinterFailure.unexpectedError());
    }
  }

  @override
  Future<Either<PrinterFailure, Unit>> updatePrinter(
    Printer printer,
    int id,
  ) async {
    try {
      final result = await _localDataProvider.updatePrinter(
        PrinterDto.fromDomain(printer),
        id,
      );

      if (result.hasError) {
        return left(result.error!);
      }

      return right(unit);
    } catch (e) {
      log('updatePrinterError', name: _logName, error: e);
      return left(const PrinterFailure.unexpectedError());
    }
  }

  // ===========================================================================
  // Timing Bluetooth
  //
  // Radio Bluetooth cuma satu, jadi pindah printer berarti disconnect lalu
  // connect ulang. Tiga jeda di bawah melindungi hal yang berbeda; ketiganya
  // sempat dipangkas ke 300ms (atau dihapus) dan itu yang membuat tiket
  // station setelah perpindahan koneksi sering hilang.
  // ===========================================================================

  /// Jeda setelah byte terakhir dikirim, sebelum koneksi boleh diputus.
  /// `writeBytes` selesai saat byte masuk socket, bukan saat kertas keluar.
  static const _kPostPrintSettle = Duration(milliseconds: 500);

  /// Jeda setelah connect berhasil. Channel SPP dan firmware printer belum
  /// tentu siap saat `connect()` return; menulis terlalu cepat membuat
  /// byte-byte awal hilang.
  static const _kPostConnectSettle = Duration(milliseconds: 800);

  /// Batas menunggu link Bluetooth benar-benar lepas setelah disconnect.
  static const _kDisconnectTimeout = Duration(seconds: 2);

  /// Backoff antar percobaan connect. Panjangnya menentukan jumlah percobaan.
  /// Retry hanya berjalan saat gagal, jadi tidak menambah waktu di jalur normal.
  static const _kConnectBackoff = [
    Duration(milliseconds: 500),
    Duration(milliseconds: 1200),
  ];

  static const _kChunkSize = 1024;
  static const _kChunkDelay = Duration(milliseconds: 50);

  @override
  Future<Either<PrinterFailure, bool>> printStruct(
    Printer printer,
    List<int> printData,
  ) async {
    if (printer.type == 'Bluetooth') {
      return _bluetoothLock.synchronized(
        () => _printBluetooth(printer, printData),
      );
    }
    return _printToNetworkPrinter(printer, printData);
  }

  Future<Either<PrinterFailure, bool>> _printBluetooth(
    Printer printer,
    List<int> printData,
  ) async {
    try {
      final connected = await _ensureBluetoothConnected(printer.address);
      if (connected.isLeft()) return connected;

      log(
        'Printer connected to bluetooth: ${printer.name}, ${printer.address}',
        name: _logName,
      );

      final printResult = await _writeBytesChunked(printData);
      log('Print result ${printer.name}: $printResult', name: _logName);

      if (!printResult) {
        // Tulis yang gagal di tengah jalan menyisakan koneksi dengan status
        // tidak jelas — paksa reconnect pada cetakan berikutnya.
        _connectedMac = null;
        FirebaseCrashlytics.instance.recordError(
          'Failed to print to ${printer.name}',
          null,
          reason: 'Failed to write bytes to Bluetooth printer',
          information: [
            'function: _writeBytesChunked(printData)',
            'Printer: ${printer.name}',
            'MAC: ${printer.address}',
            'bytes: ${printData.length}',
            'in: $_logName',
          ],
        );
        return left(
          PrinterFailure.dynamicErrorMessage(
            'Gagal mengirim data ke ${printer.name}',
          ),
        );
      }

      // Printer masih menghabiskan buffer-nya. Memutus koneksi sekarang
      // memotong cetakan, dan membuat connect berikutnya gagal.
      await Future.delayed(_kPostPrintSettle);

      return right(true);
    } catch (e, stackTrace) {
      _connectedMac = null;
      FirebaseCrashlytics.instance.recordError(
        e,
        stackTrace,
        reason: 'Error printing ${printer.name}',
        information: ['Printer: ${printer.name}', 'MAC: ${printer.address}'],
      );
      log('Error printing bluetooth', name: _logName, error: e);
      return left(
        const PrinterFailure.dynamicErrorMessage('Error printing struct'),
      );
    }
  }

  /// Memastikan radio tersambung ke [macAddress], reconnect kalau perlu.
  Future<Either<PrinterFailure, bool>> _ensureBluetoothConnected(
    String macAddress,
  ) async {
    // Izin runtime Bluetooth hilang setiap kali app di-reinstall, dan sebelumnya
    // hanya diminta dari dialog pilih perangkat di halaman pengaturan. Kalau
    // kasir tidak pernah membuka dialog itu, `connect()` gagal terus tanpa
    // penjelasan. Dipastikan di sini supaya semua jalur cetak ikut terlindungi.
    final hasPermission = await _ensureBluetoothPermission();

    final isConnected = await PrintBluetoothThermal.connectionStatus;
    final isAdapterOn = await _isBluetoothOn();
    final isPaired = await _isPaired(macAddress);

    log(
      'Bluetooth state: connected=$isConnected, '
      'connectedMac=${_connectedMac ?? "-"}, target=$macAddress, '
      'permission=$hasPermission, adapterOn=$isAdapterOn, paired=$isPaired',
      name: _logName,
    );

    if (!hasPermission) {
      return left(
        const PrinterFailure.dynamicErrorMessage(
          'Izin Bluetooth belum diberikan. Buka pengaturan aplikasi dan izinkan akses "Perangkat di sekitar", lalu cetak ulang.',
        ),
      );
    }

    if (!isAdapterOn) {
      return left(
        const PrinterFailure.dynamicErrorMessage(
          'Bluetooth di perangkat ini sedang mati. Nyalakan Bluetooth, lalu cetak ulang.',
        ),
      );
    }

    // Mencoba connect ke perangkat yang tidak ter-pairing pasti gagal, jadi
    // jangan buang waktu tiga kali percobaan untuk itu.
    if (!isPaired) {
      return left(
        PrinterFailure.dynamicErrorMessage(
          'Printer ($macAddress) tidak ada di daftar perangkat Bluetooth yang terpasang. Pasangkan lewat pengaturan Bluetooth Android, lalu hubungkan lagi di pengaturan printer.',
        ),
      );
    }

    if (isConnected && _connectedMac == macAddress) {
      return right(true);
    }

    if (isConnected) {
      await _forceDisconnect();
    }

    for (var attempt = 0; attempt <= _kConnectBackoff.length; attempt++) {
      // 'read failed, socket might closed or timeout' berarti socket RFCOMM
      // sebelumnya masih setengah terbuka. Connect ulang tanpa menutupnya
      // lebih dulu akan gagal dengan error yang sama terus, jadi tiap
      // percobaan ulang harus didahului disconnect.
      if (attempt > 0) await _forceDisconnect();

      final connected = await PrintBluetoothThermal.connect(
        macPrinterAddress: macAddress,
      );

      if (connected) {
        _connectedMac = macAddress;
        await Future.delayed(_kPostConnectSettle);
        return right(true);
      }

      if (attempt < _kConnectBackoff.length) {
        log(
          'Connect ke $macAddress gagal '
          '(percobaan ${attempt + 1}), tutup socket lalu ulangi',
          name: _logName,
        );
        await Future.delayed(_kConnectBackoff[attempt]);
      }
    }

    _connectedMac = null;

    FirebaseCrashlytics.instance.recordError(
      'Failed to connect to Bluetooth printer',
      null,
      reason: 'Failed to connect to Bluetooth printer after retries',
      information: [
        'function: _ensureBluetoothConnected(String macAddress)',
        'macAddress: $macAddress',
        'paired: $isPaired',
        'attempts: ${_kConnectBackoff.length + 1}',
        'in: $_logName',
      ],
    );

    // Sampai di sini printer sudah dipastikan ter-pairing dan Bluetooth hidup,
    // jadi sisanya adalah printer yang tidak merespons.
    return left(
      PrinterFailure.dynamicErrorMessage(
        'Printer ($macAddress) tidak merespons. Matikan lalu nyalakan printernya, pastikan tidak sedang tersambung ke perangkat atau aplikasi lain, lalu cetak ulang.',
      ),
    );
  }

  /// Apakah radio Bluetooth perangkat ini menyala.
  Future<bool> _isBluetoothOn() async {
    try {
      return await PrintBluetoothThermal.bluetoothEnabled;
    } catch (e) {
      log('Gagal membaca status Bluetooth', name: _logName, error: e);
      return true; // jangan menghalangi cetak kalau kita tidak tahu
    }
  }

  /// Apakah [macAddress] masih terdaftar sebagai perangkat Bluetooth ter-pairing.
  Future<bool> _isPaired(String macAddress) async {
    try {
      final paired = await PrintBluetoothThermal.pairedBluetooths;
      final target = macAddress.toUpperCase();

      log(
        'Paired devices: ${paired.map((e) => "${e.name}=${e.macAdress}").join(", ")}',
        name: _logName,
      );

      return paired.any((e) => e.macAdress.toUpperCase() == target);
    } catch (e) {
      log('Gagal membaca daftar paired device', name: _logName, error: e);
      return true; // jangan menuduh belum ter-pairing kalau kita tidak tahu
    }
  }

  /// Memastikan izin runtime Bluetooth ada, meminta ke user kalau belum.
  ///
  /// Di Android 12+ `BLUETOOTH_CONNECT` adalah izin runtime — tanpa itu
  /// `connect()` selalu gagal, dan errornya tidak menyebut soal izin sama
  /// sekali sehingga tampak seperti printer rusak.
  Future<bool> _ensureBluetoothPermission() async {
    try {
      var status = await Permission.bluetoothConnect.status;

      if (status.isDenied) {
        status = await Permission.bluetoothConnect.request();
      }

      final scan = await Permission.bluetoothScan.status;
      if (scan.isDenied) await Permission.bluetoothScan.request();

      if (!status.isGranted) {
        log('Izin bluetoothConnect: $status', name: _logName);
      }

      return status.isGranted;
    } catch (e) {
      log('Gagal memeriksa izin Bluetooth', name: _logName, error: e);
      // Perangkat di bawah Android 12 tidak mengenal izin ini — jangan
      // menghalangi cetak hanya karena pemeriksaannya gagal.
      return true;
    }
  }

  /// Menutup socket Bluetooth apa pun keadaannya, lalu menunggu link lepas.
  ///
  /// `disconnect` dipanggil walau `connectionStatus` bilang tidak tersambung:
  /// socket yang setengah terbuka sering melaporkan `false` padahal masih
  /// memblokir connect berikutnya.
  Future<void> _forceDisconnect() async {
    try {
      await PrintBluetoothThermal.disconnect;
    } catch (e) {
      log('Disconnect gagal, diabaikan', name: _logName, error: e);
    }

    _connectedMac = null;
    await _waitUntilDisconnected();
  }

  /// Teardown RFCOMM di Android berjalan asinkron: `disconnect` selesai
  /// sebelum link benar-benar lepas. Menunggu kondisinya (bukan durasi tetap)
  /// supaya perangkat yang cepat tidak ikut dihukum jeda panjang.
  Future<void> _waitUntilDisconnected() async {
    final deadline = DateTime.now().add(_kDisconnectTimeout);

    while (DateTime.now().isBefore(deadline)) {
      if (!await PrintBluetoothThermal.connectionStatus) return;
      await Future.delayed(const Duration(milliseconds: 100));
    }

    log(
      'Bluetooth masih tersambung setelah ${_kDisconnectTimeout.inMilliseconds}ms',
      name: _logName,
    );
  }

  Future<Either<PrinterFailure, bool>> _printToNetworkPrinter(
    Printer printer,
    List<int> printData,
  ) async {
    try {
      final printResult = await _printNetwork(printer.address, printData);

      if (!printResult) {
        FirebaseCrashlytics.instance.recordError(
          'Failed to print to Network Printer',
          null,
          reason: 'Failed to print to Network Printer',
          information: [
            'function: _printNetwork(printer.address, printData)',
            'Printer: ${printer.name}',
            'ipAddress: ${printer.address}',
            'bytes: ${printData.length}',
            'in: $_logName',
          ],
        );
        // Dulu ini `right(false)`, yang lolos sebagai sukses ke pemanggil —
        // kasir melihat "berhasil dicetak" padahal tidak ada kertas keluar.
        return left(
          PrinterFailure.dynamicErrorMessage(
            'Tidak bisa mencetak ke ${printer.name} (${printer.address})',
          ),
        );
      }

      return right(true);
    } catch (e, stackTrace) {
      FirebaseCrashlytics.instance.recordError(
        e,
        stackTrace,
        reason: 'Error printing ${printer.name}',
        information: ['Printer: ${printer.name}', 'IP: ${printer.address}'],
      );
      log('Error printing network', name: _logName, error: e);
      return left(
        const PrinterFailure.dynamicErrorMessage('Error printing struct'),
      );
    }
  }

  Future<bool> _printNetwork(String ipAddress, List<int> printData) async {
    try {
      final printer = PrinterNetworkManager(
        ipAddress,
        port: 9100,
        timeout: const Duration(seconds: 15),
      );

      final PosPrintResult connect = await printer.connect();
      if (connect != PosPrintResult.success) {
        log('Failed to connect to Network printer: ${connect.msg}');
        return false;
      }

      final PosPrintResult printing = await printer.printTicket(printData);
      printer.disconnect();

      if (printing != PosPrintResult.success) {
        log('Failed to print via Network printer: ${printing.msg}');
        return false;
      }

      log('Successfully printed via Network printer: $ipAddress');
      return true;
    } catch (e, stackTrace) {
      FirebaseCrashlytics.instance.recordError(
        e,
        stackTrace,
        reason: 'Error printing via Network',
        information: [
          'function: _printNetwork(String ipAddress, List<int> printData)',
          'ipAddress: $ipAddress',
        ],
      );
      log('Error printing via Network: $e');
      return false;
    }
  }

  Future<bool> _writeBytesChunked(List<int> data) async {
    for (int i = 0; i < data.length; i += _kChunkSize) {
      final end = i + _kChunkSize > data.length ? data.length : i + _kChunkSize;

      final result = await PrintBluetoothThermal.writeBytes(
        data.sublist(i, end),
      );
      if (!result) return false;

      if (end < data.length) await Future.delayed(_kChunkDelay);
    }
    return true;
  }

  // ===========================================================================
  // Orkestrasi cetak
  // ===========================================================================

  @override
  Stream<List<PrintStationResult>> printStations({
    required Order order,
    required List<PrintStation> stations,
  }) {
    final controller = StreamController<List<PrintStationResult>>();
    controller.onListen = () => _runPrintJob(order, stations, controller);
    return controller.stream;
  }

  Future<void> _runPrintJob(
    Order order,
    List<PrintStation> stations,
    StreamController<List<PrintStationResult>> controller,
  ) async {
    final results = <PrintStation, PrintStationResult>{
      for (final station in stations)
        station: PrintStationResult.pending(station),
    };

    void publish() {
      if (controller.isClosed) return;
      controller.add([for (final station in stations) results[station]!]);
    }

    void mark(PrintStation station, PrintStationResult result) {
      results[station] = result;
      publish();
    }

    publish();

    try {
      // Job diserialkan supaya dua kali cetak tidak saling menyelipkan tiket.
      await _jobLock.synchronized(() async {
        final outlet = await _outletLocalDatasource.currentOutlet();
        final user = await _authLocalDataProvider.currentUser();

        final plans = <_StationPlan>[];

        // Printer diresolusi di depan supaya kita tahu station mana yang lewat
        // Bluetooth dan mana yang lewat jaringan sebelum mulai mencetak.
        for (final station in stations) {
          final items = _itemsFor(order, station);

          if (items.isEmpty) {
            mark(
              station,
              results[station]!.copyWith(
                status: PrintStationStatus.skipped,
                message: 'Tidak ada item untuk station ini',
              ),
            );
            continue;
          }

          final record = await _localDataProvider.findPrinterByCode(
            station.printerCode,
          );

          if (!record.hasData) {
            FirebaseCrashlytics.instance.recordError(
              '${station.printerCode} printer not found',
              null,
              reason: 'Printer belum diatur di halaman pengaturan',
              information: [
                'Order ID: ${order.id}',
                'Station: ${station.name}',
              ],
            );
            mark(
              station,
              results[station]!.copyWith(
                status: PrintStationStatus.failed,
                message:
                    'Printer ${station.label} belum diatur di halaman pengaturan',
              ),
            );
            continue;
          }

          plans.add(
            _StationPlan(
              station: station,
              printer: record.data!.toDomain(),
              order: order.copyWith(orderItems: items),
            ),
          );
        }

        Future<void> run(_StationPlan plan) async {
          final stopwatch = Stopwatch()..start();

          mark(
            plan.station,
            results[plan.station]!.copyWith(
              status: PrintStationStatus.printing,
            ),
          );

          final result = await _printStation(plan, outlet, user.name);
          stopwatch.stop();

          mark(
            plan.station,
            result.fold(
              (failure) => PrintStationResult(
                station: plan.station,
                status: PrintStationStatus.failed,
                message: _failureMessage(failure),
                elapsed: stopwatch.elapsed,
              ),
              (_) => PrintStationResult(
                station: plan.station,
                status: PrintStationStatus.success,
                elapsed: stopwatch.elapsed,
              ),
            ),
          );
        }

        final bluetooth = plans.where((plan) => plan.isBluetooth).toList();
        final network = plans.where((plan) => !plan.isBluetooth).toList();

        await Future.wait([
          // Bluetooth berurutan — radionya cuma satu.
          _runSequentially(_groupedByAddress(bluetooth), run),
          // Jaringan paralel — tiap printer punya IP sendiri dan tidak
          // berebut radio dengan Bluetooth.
          ...network.map(run),
        ]);
      });
    } catch (e, stackTrace) {
      FirebaseCrashlytics.instance.recordError(
        e,
        stackTrace,
        reason: 'Print job error',
        information: ['Order ID: ${order.id}'],
      );
      log('Error running print job', name: _logName, error: e);

      for (final station in stations) {
        if (results[station]!.isFinished) continue;
        results[station] = results[station]!.copyWith(
          status: PrintStationStatus.failed,
          message: 'Terjadi kesalahan saat mencetak',
        );
      }
      publish();
    } finally {
      await controller.close();
    }
  }

  Future<Either<PrinterFailure, Unit>> _printStation(
    _StationPlan plan,
    Outlet outlet,
    String cashierName,
  ) async {
    try {
      log('Starting to print ${plan.station.name}', name: _logName);

      final payload = await _buildPayload(plan, outlet, cashierName);
      final result = await printStruct(plan.printer, payload);

      log('Finished printing ${plan.station.name}', name: _logName);

      return result.map((_) => unit);
    } catch (e, stackTrace) {
      FirebaseCrashlytics.instance.recordError(
        e,
        stackTrace,
        reason: 'Print station error: ${plan.station.name}',
        information: [
          'Order ID: ${plan.order.id}',
          'Printer: ${plan.printer.name}',
        ],
      );
      log('Error printing ${plan.station.name}', name: _logName, error: e);
      return left(
        PrinterFailure.dynamicErrorMessage(
          'Gagal menyiapkan cetakan ${plan.station.label}',
        ),
      );
    }
  }

  Future<List<int>> _buildPayload(
    _StationPlan plan,
    Outlet outlet,
    String cashierName,
  ) {
    final ui = PrintUi();
    final order = plan.order;
    final paper = plan.printer.paper.toIntegerFromText;

    return switch (plan.station) {
      PrintStation.receipt => ui.printOrder(
        order: order,
        outlet: outlet,
        cashierName: cashierName,
        paper: paper,
      ),
      PrintStation.cashier => ui.printCashier(
        order: order,
        outlet: outlet,
        cashierName: cashierName,
        paper: paper,
      ),
      PrintStation.checker => ui.printChecker(
        order: order,
        outlet: outlet,
        cashierName: cashierName,
        paper: paper,
      ),
      PrintStation.kitchen => ui.printKitchen(
        order: order,
        outlet: outlet,
        cashierName: cashierName,
        paper: paper,
      ),
      PrintStation.bar => ui.printBar(
        order: order,
        outlet: outlet,
        cashierName: cashierName,
        paper: paper,
      ),
      PrintStation.voided => ui.printVoid(
        order: order,
        outlet: outlet,
        cashierName: cashierName,
        paper: paper,
      ),
      PrintStation.splitBill => ui.printSplit(
        order: order,
        outlet: outlet,
        cashierName: cashierName,
        paper: paper,
      ),
    };
  }

  List<OrderItem> _itemsFor(Order order, PrintStation station) {
    final type = station.itemPrinterType;
    if (type == null) return order.orderItems;
    return order.orderItems.where((item) => item.printerType == type).toList();
  }

  /// Mengelompokkan station per alamat printer supaya perpindahan koneksi
  /// terjadi sesedikit mungkin — tiap perpindahan berarti disconnect dan
  /// connect ulang di radio yang sama. Urutan kemunculan alamat dipertahankan,
  /// jadi struk pelanggan tetap keluar lebih dulu.
  List<_StationPlan> _groupedByAddress(List<_StationPlan> plans) {
    final grouped = <String, List<_StationPlan>>{};
    for (final plan in plans) {
      grouped.putIfAbsent(plan.printer.address, () => []).add(plan);
    }
    return [for (final group in grouped.values) ...group];
  }

  Future<void> _runSequentially(
    List<_StationPlan> plans,
    Future<void> Function(_StationPlan) run,
  ) async {
    for (final plan in plans) {
      await run(plan);
    }
  }

  String _failureMessage(PrinterFailure failure) => failure.map(
    serverError: (_) => 'Terjadi kesalahan pada server',
    unexpectedError: (_) => 'Terjadi kesalahan, silahkan coba lagi',
    empty: (_) => 'Tidak ada data',
    localStorageError: (value) => value.erroMessage,
    dynamicErrorMessage: (value) => value.erroMessage,
  );
}

class _StationPlan {
  final PrintStation station;
  final Printer printer;

  /// Order yang sudah difilter untuk station ini — kitchen dan bar hanya
  /// memuat item miliknya.
  final Order order;

  const _StationPlan({
    required this.station,
    required this.printer,
    required this.order,
  });

  bool get isBluetooth => printer.type == 'Bluetooth';
}