import 'dart:async';
import 'package:flutter/services.dart';

class ScanResult {
  final String barcode;
  final String codeType;

  ScanResult({required this.barcode, required this.codeType});
}

class ScannerService {
  static const _eventChannel = EventChannel('com.example.pad_scanner/scan');
  static Stream<ScanResult>? _sharedScanStream;

  Stream<ScanResult> get scanResults {
    _sharedScanStream ??= _createSharedScanStream();
    return _sharedScanStream!;
  }

  static Stream<ScanResult> _createSharedScanStream() {
    return _eventChannel
        .receiveBroadcastStream()
        .map((event) => event as Map)
        .map(
          (event) => ScanResult(
            barcode: event['barcode'] as String? ?? '',
            codeType: event['codeType'] as String? ?? 'UNKNOWN',
          ),
        )
        .asBroadcastStream();
  }
}