import 'dart:async';
import 'dart:typed_data';

import 'package:flutter_bluetooth_serial/flutter_bluetooth_serial.dart';

/// Wraps flutter_bluetooth_serial for SPP/RFCOMM Classic BT.
class BtService {
  BluetoothConnection? _connection;
  final StreamController<Uint8List> _rawFrameController =
      StreamController<Uint8List>.broadcast();

  bool get isConnected => _connection?.isConnected ?? false;

  Stream<Uint8List> get rawStream => _rawFrameController.stream;

  Future<List<BluetoothDevice>> getPairedDevices() async {
    return FlutterBluetoothSerial.instance.getBondedDevices();
  }

  Future<void> connect(BluetoothDevice device) async {
    if (_connection != null) {
      await disconnect();
    }
    _connection = await BluetoothConnection.toAddress(device.address);
    _connection!.input!.listen(
      (Uint8List data) {
        if (!_rawFrameController.isClosed) {
          _rawFrameController.add(data);
        }
      },
      onDone: () {
        _rawFrameController.addError('BT connection closed');
      },
      onError: (Object e) {
        _rawFrameController.addError(e);
      },
    );
  }

  Future<void> write(Uint8List data) async {
    if (_connection?.isConnected ?? false) {
      _connection!.output.add(data);
      await _connection!.output.allSent;
    }
  }

  Future<void> disconnect() async {
    await _connection?.close();
    _connection = null;
  }

  void dispose() {
    disconnect();
    _rawFrameController.close();
  }
}