refactor: structured logging in applogic

Use tracing for logging in applogic. Replace the simplelog
implementation with tracing-subscriber. Implement a tracing layer for
sending logs to the Dart side. The layer is used at android and ios. On
desktop, the logs are printed to the console via the tracing-subscriber
formatter.

Also configure the logging formatting in Dart to use the same format as
the Rust tracing logging. Logs from Dart are prefixed with `[F]` and
logs from Rust are prefixed with `[R]`.

app/lib/logging.dart

@@ -0,0 +1,31 @@
+import 'package:flutter/foundation.dart';
+import 'package:logging/logging.dart';
+import 'package:prototype/core/api/logging.dart';
+
+/// Initializes Dart and Rust logging
+///
+/// Also configures the format of the logs.
+void initLogging() {
+  // Init Dart logging
+  Logger.root.level = kDebugMode ? Level.FINE : Level.INFO;
+  Logger.root.onRecord.listen((record) {
+    print(
+        '[F] ${record.time} ${record.level.name} ${record.loggerName}: ${record.message}');
+  });
+
+  // Rust Logging
+  createLogStream().listen((event) {
+    print(
+        '[R] ${event.time.toLocal()} ${event.level.asString} ${event.target}: ${event.msg}');
+  });
+}
+
+extension on LogEntryLevel {
+  String get asString => switch (this) {
+        LogEntryLevel.trace => 'TRACE',
+        LogEntryLevel.debug => 'DEBUG',
+        LogEntryLevel.info => ' INFO',
+        LogEntryLevel.warn => ' WARN',
+        LogEntryLevel.error => 'ERROR'
+      };
+}

app/lib/main.dart

@@ -2,36 +2,18 @@
 //
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
-import 'package:logging/logging.dart';
 import 'package:prototype/app.dart';
-import 'package:prototype/core/api/mobile_logging.dart';
 import 'package:prototype/core/frb_generated.dart';
+import 'package:prototype/logging.dart';
 
 void main() async {
-  _initRust();
-  _initLogging();
+  await RustLib.init();
+  initLogging();
 
   runApp(const App());
 }
 
-void _initLogging() {
-  Logger.root.level = kDebugMode ? Level.FINE : Level.INFO;
-  Logger.root.onRecord.listen((record) {
-    print('${record.level.name}: ${record.time}: ${record.message}');
-  });
-}
-
-Future<void> _initRust() async {
-  // FRB
-  await RustLib.init();
-  // Logging
-  createLogStream().listen((event) {
-    print('Rust: ${event.level} ${event.tag} ${event.msg} ${event.timeMillis}');
-  });
-}
-
 void showErrorBanner(
   ScaffoldMessengerState messengerState,
   String errorDescription,

applogic/Cargo.toml

@@ -13,15 +13,13 @@ description = "Multi-platform client application logic"
 [lib]
 crate-type = ["cdylib", "staticlib", "lib"]
 
-[target.'cfg(target_os = "android")'.dependencies]
-android_logger = { version = "0.14" }
-
-[target.'cfg(target_os = "ios")'.dependencies]
-oslog = { version = "0.2" }
-
 [dependencies]
-log = { version = "0.4", features = ["kv"] }
-simplelog = { version = "0.12" }
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = [
+    "env-filter",
+    "parking_lot",
+] }
+parking_lot = "0.12"
 uuid = { version = "1", features = ["v4"] }
 phnxcoreclient = { path = "../coreclient" }
 phnxapiclient = { path = "../apiclient" }
@@ -32,7 +30,6 @@ serde_json = "1"
 tokio = { version = "1.39", features = ["rt", "macros"] }
 flutter_rust_bridge = { version = "=2.7.0", features = ["chrono", "uuid"] }
 notify-rust = "4"
-lazy_static = "1.5"
 chrono = { workspace = true }
 jni = "0.21"
 

applogic/src/api/logging.rs

@@ -0,0 +1,39 @@
+// SPDX-FileCopyrightText: 2024 Phoenix R&D GmbH <[email protected]>
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+use chrono::{DateTime, Utc};
+
+use crate::StreamSink;
+
+pub struct LogEntry {
+    pub time: DateTime<Utc>,
+    pub level: LogEntryLevel,
+    pub tag: String,
+    pub target: String,
+    pub msg: String,
+}
+
+pub enum LogEntryLevel {
+    Trace,
+    Debug,
+    Info,
+    Warn,
+    Error,
+}
+
+impl From<tracing::Level> for LogEntryLevel {
+    fn from(level: tracing::Level) -> Self {
+        match level {
+            tracing::Level::TRACE => LogEntryLevel::Trace,
+            tracing::Level::DEBUG => LogEntryLevel::Debug,
+            tracing::Level::INFO => LogEntryLevel::Info,
+            tracing::Level::WARN => LogEntryLevel::Warn,
+            tracing::Level::ERROR => LogEntryLevel::Error,
+        }
+    }
+}
+
+pub fn create_log_stream(s: StreamSink<LogEntry>) {
+    crate::logging::dart::set_stream_sink(s)
+}