meshcore-open/lib/services/usb_serial_service_web.dart
2026-03-05 02:25:05 -05:00

385 lines
11 KiB
Dart

import 'dart:async';
import 'dart:js_interop';
import 'dart:js_interop_unsafe';
import 'package:flutter/foundation.dart';
import 'package:web/web.dart' as web;
import '../utils/usb_port_labels.dart';
import 'usb_serial_frame_codec.dart';
class UsbSerialService {
UsbSerialService();
static const Map<String, String> _knownUsbNames = <String, String>{
'2886:1667': 'Seeed Wio Tracker L1',
};
static final Map<String, String> _deviceNamesByPortKey = <String, String>{};
final StreamController<Uint8List> _frameController =
StreamController<Uint8List>.broadcast();
final UsbSerialFrameDecoder _frameDecoder = UsbSerialFrameDecoder();
UsbSerialStatus _status = UsbSerialStatus.disconnected;
JSObject? _port;
JSObject? _reader;
JSObject? _writer;
String? _connectedPortName;
String? _connectedPortKey;
UsbSerialStatus get status => _status;
String? get activePortName => _connectedPortName;
Stream<Uint8List> get frameStream => _frameController.stream;
bool get isConnected => _status == UsbSerialStatus.connected;
JSObject get _navigator => JSObject.fromInteropObject(web.window.navigator);
bool get _isSupported => _navigator.has('serial');
JSObject? get _serial {
if (!_isSupported) {
return null;
}
final serial = _navigator['serial'];
return serial == null ? null : serial as JSObject;
}
Future<List<String>> listPorts() async {
if (!_isSupported) {
return const <String>[];
}
final ports = await _getAuthorizedPorts();
if (ports.isEmpty) {
return const <String>[usbRequestPortLabel];
}
return ports.map(_displayLabelForPort).toList(growable: false);
}
Future<void> connect({
required String portName,
int baudRate = 115200,
}) async {
if (_status == UsbSerialStatus.connected ||
_status == UsbSerialStatus.connecting) {
throw StateError('USB serial transport is already active');
}
if (!_isSupported) {
throw UnsupportedError('Web Serial is not supported by this browser.');
}
_status = UsbSerialStatus.connecting;
try {
final requestedPortName = normalizeUsbPortName(portName);
final authorizedPorts = await _getAuthorizedPorts();
_port = _selectPort(authorizedPorts, requestedPortName);
_port ??= await _requestPort();
if (_port == null) {
throw StateError('No USB serial device selected');
}
await _openPort(_port!, baudRate);
_connectedPortKey = _portKeyFor(_port!);
_connectedPortName = _buildDisplayLabel(_connectedPortKey!);
_writer = _getWriter(_port!);
_reader = _getReader(_port!);
_status = UsbSerialStatus.connected;
unawaited(_pumpReads());
debugPrint('USB serial opened port=$_connectedPortName via Web Serial');
} catch (error) {
_status = UsbSerialStatus.disconnected;
_connectedPortName = null;
rethrow;
}
}
Future<void> write(Uint8List data) async {
if (!isConnected || _writer == null) {
throw StateError('USB serial port is not open');
}
final packet = wrapUsbSerialTxFrame(data);
_logFrameSummary('USB TX frame', data);
final promise = _writer!.callMethod<JSPromise<JSAny?>>(
'write'.toJS,
packet.toJS,
);
await promise.toDart;
}
Future<void> disconnect() async {
if (_status == UsbSerialStatus.disconnected) return;
_status = UsbSerialStatus.disconnecting;
final reader = _reader;
final writer = _writer;
final port = _port;
_reader = null;
_writer = null;
_port = null;
_connectedPortName = null;
_connectedPortKey = null;
if (reader != null) {
try {
await reader.callMethod<JSPromise<JSAny?>>('cancel'.toJS).toDart;
} catch (_) {
// Ignore errors while closing.
}
_releaseLock(reader);
}
if (writer != null) {
_releaseLock(writer);
}
if (port != null) {
try {
await port.callMethod<JSPromise<JSAny?>>('close'.toJS).toDart;
} catch (_) {
// Ignore errors while closing.
}
}
_status = UsbSerialStatus.disconnected;
}
void updateConnectedLabel(String label) {
final trimmed = label.trim();
final portKey = _connectedPortKey;
if (trimmed.isEmpty || portKey == null) {
return;
}
_deviceNamesByPortKey[portKey] = trimmed;
_connectedPortName = _buildDisplayLabel(portKey);
}
void dispose() {
unawaited(disconnect());
unawaited(_frameController.close());
}
Future<List<JSObject>> _getAuthorizedPorts() async {
final serial = _serial;
if (serial == null) {
return const <JSObject>[];
}
final result = await serial
.callMethod<JSPromise<JSAny?>>('getPorts'.toJS)
.toDart;
return _toObjectList(result);
}
Future<JSObject?> _requestPort() async {
final serial = _serial;
if (serial == null) {
return null;
}
final result = await serial
.callMethod<JSPromise<JSAny?>>('requestPort'.toJS)
.toDart;
return result == null ? null : result as JSObject;
}
JSObject? _selectPort(List<JSObject> ports, String requestedPortName) {
if (ports.isEmpty) {
return null;
}
if (requestedPortName.isEmpty || requestedPortName == usbRequestPortLabel) {
return ports.first;
}
for (final port in ports) {
final description = _describePort(port);
if (description == requestedPortName) {
return port;
}
}
return null;
}
Future<void> _openPort(JSObject port, int baudRate) {
final options = JSObject()..['baudRate'] = baudRate.toJS;
return port.callMethod<JSPromise<JSAny?>>('open'.toJS, options).toDart;
}
JSObject? _getReader(JSObject port) {
final readable = port.getProperty<JSAny?>('readable'.toJS);
if (readable == null) {
throw StateError('Web Serial port is not readable');
}
final readableObject = readable as JSObject;
return readableObject.callMethod<JSAny?>('getReader'.toJS) as JSObject;
}
JSObject? _getWriter(JSObject port) {
final writable = port.getProperty<JSAny?>('writable'.toJS);
if (writable == null) {
throw StateError('Web Serial port is not writable');
}
final writableObject = writable as JSObject;
return writableObject.callMethod<JSAny?>('getWriter'.toJS) as JSObject;
}
Future<void> _pumpReads() async {
final reader = _reader;
if (reader == null) return;
try {
while (_status == UsbSerialStatus.connected &&
identical(reader, _reader)) {
final result = await reader
.callMethod<JSPromise<JSAny?>>('read'.toJS)
.toDart;
if (result == null) {
break;
}
final resultObject = result as JSObject;
final doneValue = resultObject.getProperty<JSAny?>('done'.toJS);
final done = doneValue != null && doneValue.dartify() == true;
if (done) {
break;
}
final value = resultObject.getProperty<JSAny?>('value'.toJS);
final bytes = _coerceBytes(value);
if (bytes != null && bytes.isNotEmpty) {
_ingestRawBytes(bytes);
}
}
} catch (error, stackTrace) {
if (_status == UsbSerialStatus.connected) {
_frameController.addError(error, stackTrace);
}
} finally {
_releaseLock(reader);
if (_status == UsbSerialStatus.connected && identical(reader, _reader)) {
_frameController.addError(StateError('USB serial connection closed'));
}
}
}
Uint8List? _coerceBytes(JSAny? value) {
if (value == null) return null;
try {
return (value as JSUint8Array).toDart;
} catch (_) {
// Fall back to array-like coercion below.
}
final object = value as JSObject;
if (object.has('length')) {
final lengthValue = object.getProperty<JSAny?>('length'.toJS)?.dartify();
if (lengthValue is num) {
final length = lengthValue.toInt();
final bytes = Uint8List(length);
for (var i = 0; i < length; i++) {
final item = object.getProperty<JSAny?>(i.toString().toJS)?.dartify();
if (item is num) {
bytes[i] = item.toInt();
}
}
return bytes;
}
}
return null;
}
List<JSObject> _toObjectList(JSAny? value) {
if (value == null) {
return const <JSObject>[];
}
final object = value as JSObject;
if (!object.has('length')) {
return const <JSObject>[];
}
final lengthValue = object.getProperty<JSAny?>('length'.toJS)?.dartify();
if (lengthValue is! num) {
return const <JSObject>[];
}
final length = lengthValue.toInt();
final items = <JSObject>[];
for (var i = 0; i < length; i++) {
final item = object.getProperty<JSAny?>(i.toString().toJS);
if (item != null) {
items.add(item as JSObject);
}
}
return items;
}
String _describePort(JSObject port) {
try {
final info = port.callMethod<JSAny?>('getInfo'.toJS);
if (info == null) {
return usbRequestPortLabel;
}
final infoObject = info as JSObject;
final vendorId = infoObject
.getProperty<JSAny?>('usbVendorId'.toJS)
?.dartify();
final productId = infoObject
.getProperty<JSAny?>('usbProductId'.toJS)
?.dartify();
final hasVendor = vendorId is num;
final hasProduct = productId is num;
return describeWebUsbPort(
vendorId: hasVendor ? vendorId.toInt() : null,
productId: hasProduct ? productId.toInt() : null,
knownUsbNames: _knownUsbNames,
);
} catch (_) {
return usbRequestPortLabel;
}
}
String _portKeyFor(JSObject port) => _describePort(port);
String _displayLabelForPort(JSObject port) =>
_buildDisplayLabel(_portKeyFor(port));
String _buildDisplayLabel(String portKey) {
return buildUsbDisplayLabel(
basePortLabel: portKey,
deviceName: _deviceNamesByPortKey[portKey],
);
}
void _releaseLock(JSObject resource) {
try {
resource.callMethod<JSAny?>('releaseLock'.toJS);
} catch (_) {
// Ignore lock release failures.
}
}
void _ingestRawBytes(Uint8List bytes) {
for (final packet in _frameDecoder.ingest(bytes)) {
if (!packet.isRxFrame) {
debugPrint(
'USB ignored packet start=0x${packet.frameStart.toRadixString(16).padLeft(2, '0')} len=${packet.payload.length}',
);
continue;
}
_frameController.add(packet.payload);
}
}
void _logFrameSummary(String prefix, Uint8List bytes) {
if (bytes.isEmpty) {
debugPrint('$prefix len=0');
return;
}
debugPrint('$prefix code=${bytes[0]} len=${bytes.length}');
}
}
enum UsbSerialStatus { disconnected, connecting, connected, disconnecting }