feat(logging): tracing broadcast layer for real-time log streaming

Cargo.toml

@@ -23,6 +23,7 @@ prost = "0.14"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter", "json", "local-time"] }
 tracing-appender = "0.2"
+time = { version = "0.3", features = ["formatting", "local-offset"] }
 anyhow = "1.0"
 mime_guess = "2.0"
 base64 = "0.22"

src/logging.rs

@@ -1,27 +1,93 @@
 use std::path::PathBuf;
+use std::sync::OnceLock;
+use tokio::sync::broadcast;
+use tracing::field::{Field, Visit};
+use tracing::{Event, Subscriber};
 use tracing_appender::rolling::{RollingFileAppender, Rotation};
+use tracing_subscriber::layer::Context;
+use tracing_subscriber::registry::LookupSpan;
+use tracing_subscriber::Layer;
 use tracing_subscriber::{
     EnvFilter, fmt, fmt::time::LocalTime, layer::SubscriberExt, util::SubscriberInitExt,
 };
 
-/// Get the default log directory path: ~/.picobot/logs
+#[derive(Clone, Debug)]
+pub struct LogEvent {
+    pub ts: String,
+    pub level: String,
+    pub target: String,
+    pub message: String,
+}
+
+static LOG_TX: OnceLock<broadcast::Sender<LogEvent>> = OnceLock::new();
+
+pub fn log_sender() -> Option<broadcast::Sender<LogEvent>> {
+    LOG_TX.get().cloned()
+}
+
+struct MessageVisitor(String);
+
+impl Visit for MessageVisitor {
+    fn record_debug(&mut self, field: &Field, value: &dyn std::fmt::Debug) {
+        if field.name() == "message" {
+            self.0 = format!("{value:?}");
+        }
+    }
+
+    fn record_str(&mut self, field: &Field, value: &str) {
+        if field.name() == "message" {
+            self.0 = value.to_string();
+        }
+    }
+}
+
+struct BroadcastLayer;
+
+impl<S> Layer<S> for BroadcastLayer
+where
+    S: Subscriber + for<'a> LookupSpan<'a>,
+{
+    fn on_event(&self, event: &Event<'_>, _ctx: Context<'_, S>) {
+        let Some(tx) = LOG_TX.get() else {
+            return;
+        };
+        if tx.receiver_count() == 0 {
+            return;
+        }
+
+        let mut visitor = MessageVisitor(String::new());
+        event.record(&mut visitor);
+
+        let ts = time::OffsetDateTime::now_local()
+            .unwrap_or_else(|_| time::OffsetDateTime::now_utc())
+            .format(&time::format_description::well_known::Rfc3339)
+            .unwrap_or_default();
+
+        let _ = tx.send(LogEvent {
+            ts,
+            level: event.metadata().level().to_string(),
+            target: event.metadata().target().to_string(),
+            message: visitor.0,
+        });
+    }
+}
+
 pub fn get_default_log_dir() -> PathBuf {
     let home = dirs::home_dir().unwrap_or_else(|| PathBuf::from("."));
     home.join(".picobot").join("logs")
 }
 
-/// Get the default config file path: ~/.picobot/config.json
 pub fn get_default_config_path() -> PathBuf {
     let home = dirs::home_dir().unwrap_or_else(|| PathBuf::from("."));
     home.join(".picobot").join("config.json")
 }
 
-/// Initialize logging with file appender
-/// Logs are written to ~/.picobot/logs/ with daily rotation
 pub fn init_logging() {
+    let (tx, _) = broadcast::channel::<LogEvent>(1024);
+    let _ = LOG_TX.set(tx);
+
     let log_dir = get_default_log_dir();
 
-    // Create log directory if it doesn't exist
     if !log_dir.exists()
         && let Err(e) = std::fs::create_dir_all(&log_dir)
     {
@@ -32,10 +98,8 @@ pub fn init_logging() {
         );
     }
 
-    // Create file appender with daily rotation
     let file_appender = RollingFileAppender::new(Rotation::DAILY, &log_dir, "picobot.log");
 
-    // Build subscriber with both console and file output
     let env_filter = EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("info"));
 
     let file_layer = fmt::layer()
@@ -55,6 +119,7 @@ pub fn init_logging() {
         .with(env_filter)
         .with(console_layer)
         .with(file_layer)
+        .with(BroadcastLayer)
         .init();
 
     tracing::info!("Logging initialized. Log directory: {}", log_dir.display());