desktop: use tracing for logging (#13135)

packages/desktop/src-tauri/src/logging.rs

@@ -0,0 +1,83 @@
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+use std::path::{Path, PathBuf};
+use tracing_appender::non_blocking::WorkerGuard;
+use tracing_subscriber::{EnvFilter, fmt, layer::SubscriberExt, util::SubscriberInitExt};
+
+const MAX_LOG_AGE_DAYS: u64 = 7;
+const TAIL_LINES: usize = 1000;
+
+static LOG_PATH: std::sync::OnceLock<PathBuf> = std::sync::OnceLock::new();
+
+pub fn init(log_dir: &Path) -> WorkerGuard {
+    std::fs::create_dir_all(log_dir).expect("failed to create log directory");
+
+    cleanup(log_dir);
+
+    let timestamp = chrono::Local::now().format("%Y-%m-%d_%H-%M-%S");
+    let filename = format!("opencode-desktop_{timestamp}.log");
+    let log_path = log_dir.join(&filename);
+
+    LOG_PATH
+        .set(log_path.clone())
+        .expect("logging already initialized");
+
+    let file = File::create(&log_path).expect("failed to create log file");
+    let (non_blocking, guard) = tracing_appender::non_blocking(file);
+
+    let filter = EnvFilter::try_from_default_env().unwrap_or_else(|_| {
+        if cfg!(debug_assertions) {
+            EnvFilter::new("opencode_lib=debug,opencode_desktop=debug,sidecar=debug")
+        } else {
+            EnvFilter::new("opencode_lib=info,opencode_desktop=info,sidecar=info")
+        }
+    });
+
+    tracing_subscriber::registry()
+        .with(filter)
+        .with(fmt::layer().with_writer(std::io::stderr))
+        .with(
+            fmt::layer()
+                .with_writer(non_blocking)
+                .with_ansi(false),
+        )
+        .init();
+
+    guard
+}
+
+pub fn tail() -> String {
+    let Some(path) = LOG_PATH.get() else {
+        return String::new();
+    };
+
+    let Ok(file) = File::open(path) else {
+        return String::new();
+    };
+
+    let lines: Vec<String> = BufReader::new(file)
+        .lines()
+        .map_while(Result::ok)
+        .collect();
+
+    let start = lines.len().saturating_sub(TAIL_LINES);
+    lines[start..].join("\n")
+}
+
+fn cleanup(log_dir: &Path) {
+    let cutoff = std::time::SystemTime::now()
+        - std::time::Duration::from_secs(MAX_LOG_AGE_DAYS * 24 * 60 * 60);
+
+    let Ok(entries) = std::fs::read_dir(log_dir) else {
+        return;
+    };
+
+    for entry in entries.flatten() {
+        if let Ok(meta) = entry.metadata()
+            && let Ok(modified) = meta.modified()
+            && modified < cutoff
+        {
+            let _ = std::fs::remove_file(entry.path());
+        }
+    }
+}