Use the logging package, and log from RPC.

lib/app/state.dart

@@ -1,14 +1,16 @@
 import 'dart:async';
 import 'dart:convert';
-import 'dart:developer' as developer;
 
 import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:logging/logging.dart';
 
 import '../../core/rpc.dart';
 import '../../core/state.dart';
 
 import 'models.dart';
 
+final log = Logger('app.state');
+
 final attachedDevicesProvider =
     StateNotifierProvider<AttachedDeviceNotifier, List<DeviceNode>>(
         (ref) => AttachedDeviceNotifier(ref.watch(rpcProvider)));
@@ -32,8 +34,7 @@ class AttachedDeviceNotifier extends StateNotifier<List<DeviceNode>> {
 
     if (_usbState != scan['state']) {
       var usbResult = await _rpc.command('get', ['usb']);
-      developer.log('USB state change',
-          name: 'controller', error: jsonEncode(usbResult));
+      log.info('USB state change', jsonEncode(usbResult));
 
       _usbState = usbResult['data']['state'];
 

lib/core/rpc.dart

@@ -1,12 +1,14 @@
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
-import 'dart:developer' as developer;
 
+import 'package:logging/logging.dart';
 import 'package:async/async.dart';
 
 import 'models.dart';
 
+final log = Logger('rpc');
+
 class Signaler {
   final _send = StreamController<String>();
   final _recv = StreamController<Signal>();
@@ -40,6 +42,21 @@ class _Request {
       };
 }
 
+Level _forPythonName(String name) {
+  switch (name) {
+    case 'DEBUG':
+      return Level.CONFIG;
+    case 'INFO':
+      return Level.INFO;
+    case 'WARNING':
+      return Level.WARNING;
+    case 'ERROR':
+      return Level.SEVERE;
+    default:
+      return Level.INFO;
+  }
+}
+
 class RpcSession {
   final Process _process;
   final StreamController<_Request> _requests = StreamController();
@@ -50,8 +67,18 @@ class RpcSession {
             .transform(const Utf8Decoder())
             .transform(const LineSplitter())
             .map((event) => RpcResponse.fromJson(jsonDecode(event)))) {
-    stderr.addStream(_process.stderr);
-    developer.log('Launched ykman subprocess...', name: 'rpc');
+    _process.stderr
+        .transform(const Utf8Decoder())
+        .transform(const LineSplitter())
+        .map((event) => jsonDecode(event))
+        .listen((event) {
+      Logger('rpc.${event['name']}').log(
+        _forPythonName(event['level']),
+        event['message'],
+        //time: DateTime.fromMillisecondsSinceEpoch(event['time'] * 1000),
+      );
+    });
+    log.info('Launched ykman subprocess...');
     _pump();
   }
 
@@ -68,8 +95,24 @@ class RpcSession {
     return request.completer.future;
   }
 
+  setLogLevel(Level level) {
+    String pyLevel;
+    if (level.value <= Level.CONFIG.value) {
+      pyLevel = 'debug';
+    } else if (level.value <= Level.INFO.value) {
+      pyLevel = 'info';
+    } else if (level.value <= Level.WARNING.value) {
+      pyLevel = 'warning';
+    } else if (level.value <= Level.SEVERE.value) {
+      pyLevel = 'error';
+    } else {
+      pyLevel = 'critical';
+    }
+    command('logging', [], params: {'level': pyLevel});
+  }
+
   void _send(Map data) {
-    developer.log('SEND', name: 'rpc', error: jsonEncode(data));
+    log.fine('SEND', jsonEncode(data));
     _process.stdin.writeln(jsonEncode(data));
     _process.stdin.flush();
   }
@@ -85,7 +128,7 @@ class RpcSession {
       bool completed = false;
       while (!completed) {
         final response = await _responses.next;
-        developer.log('RECV', name: 'rpc', error: jsonEncode(response));
+        log.fine('RECV', jsonEncode(response));
         response.map(
           signal: (signal) {
             request.signal?._recv.sink.add(signal);

lib/main.dart

@@ -1,10 +1,10 @@
 import 'dart:io';
-
-import 'package:flutter/material.dart';
 import 'dart:developer' as developer;
 
+import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:shared_preferences/shared_preferences.dart';
+import 'package:logging/logging.dart';
 
 import 'app.dart';
 import 'core/rpc.dart';
@@ -13,6 +13,8 @@ import 'core/state.dart';
 import 'app/main_page.dart';
 import 'error_page.dart';
 
+final log = Logger('main');
+
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
 
@@ -35,14 +37,16 @@ void main() async {
     prefProvider.overrideWithValue(await SharedPreferences.getInstance())
   ];
 
-  developer.log('Starting subprocess: $exe', name: 'main');
+  log.info('Starting subprocess: $exe');
   try {
     var rpc = await RpcSession.launch(exe!);
-    developer.log('ykman process started', name: 'main');
+    // Enable logging TODO: Make this configurable
+    _initLogging(Level.INFO, rpc);
+    log.info('ykman process started', exe);
     overrides.add(rpcProvider.overrideWithValue(rpc));
     page = const MainPage();
   } catch (e) {
-    developer.log('ykman process failed: $e', name: 'main');
+    log.warning('ykman process failed: $e');
     page = ErrorPage(error: e.toString());
   }
 
@@ -52,6 +56,22 @@ void main() async {
   ));
 }
 
+void _initLogging(Level level, RpcSession rpc) {
+  //TODO: Add support for logging to stderr and file
+  Logger.root.onRecord.listen((record) {
+    developer.log(
+      '${record.level} ${record.message}',
+      error: record.error,
+      name: record.loggerName,
+      time: record.time,
+      level: record.level.value,
+    );
+  });
+
+  Logger.root.level = level;
+  rpc.setLogLevel(level);
+}
+
 //TODO: Remove below this
 
 class MyApp extends StatelessWidget {

lib/oath/state.dart

@@ -1,15 +1,17 @@
 import 'dart:async';
 import 'dart:convert';
-import 'dart:developer' as developer;
 import 'dart:math';
 
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:shared_preferences/shared_preferences.dart';
+import 'package:logging/logging.dart';
 
 import '../core/state.dart';
 import 'models.dart';
 
+final log = Logger('oath.state');
+
 final _sessionProvider =
     Provider.autoDispose.family<RpcNodeSession, List<String>>(
   (ref, devicePath) => RpcNodeSession(
@@ -34,8 +36,7 @@ class OathStateNotifier extends StateNotifier<OathState?> {
 
   refresh() async {
     var result = await _session.command('get');
-    developer.log('application status',
-        name: 'oath', error: jsonEncode(result));
+    log.config('application status', jsonEncode(result));
     if (mounted) {
       state = OathState.fromJson(result['data']);
     }
@@ -47,7 +48,7 @@ class OathStateNotifier extends StateNotifier<OathState?> {
     var key = result['key'];
     await _session.command('validate', params: {'key': key});
     if (mounted) {
-      developer.log('UNLOCKED');
+      log.config('applet unlocked');
       state = state?.copyWith(locked: false);
     }
     return true;
@@ -117,7 +118,7 @@ class CredentialListNotifier extends StateNotifier<List<OathPair>?> {
           await _session.command('code', target: ['accounts', credential.id]);
       code = OathCode.fromJson(result);
     }
-    developer.log('Calculate', name: 'oath', error: jsonEncode(code));
+    log.config('Calculate', jsonEncode(code));
     if (mounted) {
       final creds = state!.toList();
       final i = creds.indexWhere((e) => e.credential.id == credential.id);
@@ -143,9 +144,9 @@ class CredentialListNotifier extends StateNotifier<List<OathPair>?> {
 
   refresh() async {
     if (_locked) return;
-    developer.log('refreshing credentials...', name: 'oath');
+    log.config('refreshing credentials...');
     var result = await _session.command('calculate_all', target: ['accounts']);
-    developer.log('Entries', name: 'oath', error: jsonEncode(result));
+    log.config('Entries', jsonEncode(result));
 
     if (mounted) {
       var current = state?.toList() ?? [];

pubspec.lock

@@ -304,7 +304,7 @@ packages:
     source: hosted
     version: "1.0.1"
   logging:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: logging
       url: "https://pub.dartlang.org"

pubspec.yaml

@@ -36,6 +36,7 @@ dependencies:
   # cupertino_icons: ^1.0.2
 
   async: ^2.8.2
+  logging: ^1.0.2
   shared_preferences: ^2.0.8
   flutter_riverpod: ^1.0.0
   json_annotation: ^4.3.0

yubikey-manager

@@ -1 +1 @@
-Subproject commit 739f3122a43adfcd2549374bc4cd11e88a483a8d
+Subproject commit 318b0981d545950a45a8c9b9e17de9332e1f64b5