1 files changed, 377 insertions, 0 deletions
diff --git a/crates/daemon/src/main.rs b/crates/daemon/src/main.rs
new file mode 100644
index 00000000..26a5cafd
--- /dev/null
+++ b/crates/daemon/src/main.rs
@@ -0,0 +1,377 @@
+#[allow(unused_imports)]
+use clap::Parser;
+use eyre::{Result, WrapErr, bail, eyre};
+use fs4::fs_std::FileExt;
+use std::fs::{self, File, OpenOptions};
+use std::io::{ErrorKind, Write};
+#[cfg(unix)]
+use std::os::unix::net::UnixStream as StdUnixStream;
+use std::path::{Path, PathBuf};
+use std::process::{Command, Stdio};
+use std::time::{Duration, Instant};
+use tokio::time::sleep;
+use turtle_daemon::{
+    DaemonEvent,
+    aclient::{
+        database::ClientSqlite, history::History, record::sqlite_store::SqliteStore,
+        settings::Settings,
+    },
+    client::{ControlClient, DaemonClientErrorKind, HistoryClient, classify_error},
+};
+
+#[derive(Parser, Debug)]
+#[command(infer_subcommands = true)]
+pub(crate) enum Cmd {
+    /// Start the daemon server
+    Start {
+        #[arg(long, hide = true)]
+        daemonize: bool,
+
+        /// Also write daemon logs to the console (useful for debugging)
+        #[arg(long)]
+        show_logs: bool,
+    },
+
+    /// Show the daemon's current status
+    Status,
+
+    /// Stop the daemon gracefully
+    Stop,
+}
+
+impl Cmd {
+    pub(crate) async fn run(
+        self,
+        settings: Settings,
+        store: SqliteStore,
+        history_db: ClientSqlite,
+    ) -> Result<()> {
+        match self {
+            Cmd::Start { .. } => run(settings, store, history_db).await,
+            Cmd::Status => status_cmd(&settings).await,
+            Cmd::Stop => stop_cmd(&settings).await,
+        }
+    }
+}
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    let settings = Settings::new().wrap_err("could not load client settings")?;
+    let db_path = PathBuf::from(settings.db_path.as_str());
+    let record_store_path = PathBuf::from(settings.record_store_path.as_str());
+
+    let db = ClientSqlite::new(db_path, settings.local_timeout).await?;
+    let sqlite_store = SqliteStore::new(record_store_path, settings.local_timeout).await?;
+
+    Cmd::parse().run(settings, sqlite_store, db).await
+}
+
+const DAEMON_VERSION: &str = env!("CARGO_PKG_VERSION");
+const DAEMON_PROTOCOL_VERSION: u32 = 1;
+const STARTUP_POLL: Duration = Duration::from_millis(40);
+const LOCK_POLL: Duration = Duration::from_millis(20);
+const LEGACY_DAEMON_RESTART_MESSAGE: &str = "legacy daemon detected; restart daemon manually";
+
+struct PidfileGuard {
+    file: File,
+}
+
+impl PidfileGuard {
+    fn acquire(path: &Path) -> Result<Self> {
+        let mut file = open_lock_file(path)?;
+
+        if !file.try_lock_exclusive()? {
+            bail!(
+                "daemon already running (pidfile lock busy at {})",
+                path.display()
+            );
+        }
+
+        file.set_len(0)
+            .wrap_err_with(|| format!("could not truncate daemon pidfile {}", path.display()))?;
+        writeln!(file, "{}", std::process::id())
+            .and_then(|()| writeln!(file, "{DAEMON_VERSION}"))
+            .wrap_err_with(|| format!("could not write daemon pidfile {}", path.display()))?;
+
+        Ok(Self { file })
+    }
+}
+
+impl Drop for PidfileGuard {
+    fn drop(&mut self) {
+        drop(self.file.unlock());
+    }
+}
+
+enum Probe {
+    Ready(HistoryClient),
+    NeedsRestart(String),
+    Unreachable(eyre::Report),
+}
+
+fn daemon_matches_expected(version: &str, protocol: u32) -> bool {
+    version == DAEMON_VERSION && protocol == DAEMON_PROTOCOL_VERSION
+}
+
+fn daemon_mismatch_message(version: &str, protocol: u32) -> String {
+    if protocol == DAEMON_PROTOCOL_VERSION {
+        format!("daemon is out of date: expected {DAEMON_VERSION}, got {version}")
+    } else {
+        format!("daemon protocol mismatch: expected {DAEMON_PROTOCOL_VERSION}, got {protocol}")
+    }
+}
+
+fn is_legacy_daemon_error(err: &eyre::Report) -> bool {
+    matches!(classify_error(err), DaemonClientErrorKind::Unimplemented)
+}
+
+fn open_lock_file(path: &Path) -> Result<File> {
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent)
+            .wrap_err_with(|| format!("could not create lock directory {}", parent.display()))?;
+    }
+
+    OpenOptions::new()
+        .read(true)
+        .write(true)
+        .create(true)
+        .truncate(false)
+        .open(path)
+        .wrap_err_with(|| format!("could not open lock file {}", path.display()))
+}
+
+async fn wait_for_lock(path: &Path, timeout: Duration) -> Result<File> {
+    let file = open_lock_file(path)?;
+    let start = Instant::now();
+
+    loop {
+        match file.try_lock_exclusive() {
+            Ok(true) => return Ok(file),
+            Ok(false) => {
+                if start.elapsed() >= timeout {
+                    bail!("timed out waiting for lock at {}", path.display());
+                }
+
+                sleep(LOCK_POLL).await;
+            }
+            Err(err) => {
+                return Err(eyre!("could not lock {}: {err}", path.display()));
+            }
+        }
+    }
+}
+
+async fn wait_for_pidfile_available(path: &Path, timeout: Duration) -> Result<()> {
+    let file = wait_for_lock(path, timeout).await?;
+    file.unlock()
+        .wrap_err_with(|| format!("failed to unlock {}", path.display()))?;
+    Ok(())
+}
+
+async fn connect_client(settings: &Settings) -> Result<HistoryClient> {
+    HistoryClient::new(
+        #[cfg(unix)]
+        settings.daemon.socket_path.clone(),
+    )
+    .await
+}
+
+async fn probe(settings: &Settings) -> Probe {
+    let mut client = match connect_client(settings).await {
+        Ok(client) => client,
+        Err(err) => return Probe::Unreachable(err),
+    };
+
+    match client.status().await {
+        Ok(status) => {
+            if daemon_matches_expected(&status.version, status.protocol) {
+                Probe::Ready(client)
+            } else {
+                Probe::NeedsRestart(daemon_mismatch_message(&status.version, status.protocol))
+            }
+        }
+        Err(err) => Probe::Unreachable(err),
+    }
+}
+
+async fn request_shutdown(settings: &Settings) {
+    if let Ok(mut client) = connect_client(settings).await {
+        drop(client.shutdown().await);
+    }
+}
+
+fn startup_timeout(settings: &Settings) -> Duration {
+    Duration::from_secs_f64(settings.local_timeout.max(0.5) + 2.0)
+}
+
+pub(crate) async fn start_history(settings: &Settings, history: History) -> Result<String> {
+    match async {
+        connect_client(settings)
+            .await?
+            .start_history(history.clone())
+            .await
+    }
+    .await
+    {
+        Ok(resp) => {
+            if daemon_matches_expected(&resp.version, resp.protocol) {
+                return Ok(resp.id);
+            }
+
+            Err(eyre!(
+                "{}. Restart the daemon manually",
+                daemon_mismatch_message(&resp.version, resp.protocol)
+            ))
+        }
+        Err(err) => Err(err),
+    }
+}
+
+pub(crate) async fn end_history(
+    settings: &Settings,
+    id: String,
+    duration: u64,
+    exit: i64,
+) -> Result<()> {
+    match async {
+        connect_client(settings)
+            .await?
+            .end_history(id.clone(), duration, exit)
+            .await
+    }
+    .await
+    {
+        Ok(resp) => {
+            if daemon_matches_expected(&resp.version, resp.protocol) {
+                return Ok(());
+            }
+
+            Err(eyre!(
+                "{}. Restart the daemon manually",
+                daemon_mismatch_message(&resp.version, resp.protocol)
+            ))
+        }
+        Err(err) => Err(err),
+    }
+}
+
+/// Emit a daemon event.
+pub(crate) async fn emit_event(settings: &Settings, event: DaemonEvent) {
+    // Try to connect and send
+    match ControlClient::from_settings(settings).await {
+        Ok(mut client) => {
+            if let Err(e) = client.send_event(event).await {
+                tracing::debug!(?e, "failed to send event to daemon");
+            }
+        }
+        Err(e) => {
+            tracing::debug!(?e, "daemon not available, skipping event emission");
+        }
+    }
+}
+
+pub(crate) async fn tail_client(settings: &Settings) -> Result<HistoryClient> {
+    match probe(settings).await {
+        Probe::Ready(client) => Ok(client),
+        Probe::NeedsRestart(reason) => {
+            bail!("{reason}. Restart the daemon manually");
+        }
+        Probe::Unreachable(err) if is_legacy_daemon_error(&err) => {
+            Err(err.wrap_err(LEGACY_DAEMON_RESTART_MESSAGE))
+        }
+        Probe::Unreachable(err) => Err(err),
+    }
+}
+
+async fn status_cmd(settings: &Settings) -> Result<()> {
+    match probe(settings).await {
+        Probe::Ready(mut client) => {
+            let status = client.status().await?;
+            println!("Daemon running");
+            println!("  PID:      {}", status.pid);
+            println!("  Version:  {}", status.version);
+            println!("  Protocol: {}", status.protocol);
+            println!("  Healthy:  {}", status.healthy);
+            #[cfg(unix)]
+            println!("  Socket:   {}", settings.daemon.socket_path);
+        }
+        Probe::NeedsRestart(reason) => {
+            println!("Daemon running (needs restart)");
+            println!("  Reason: {reason}");
+        }
+        Probe::Unreachable(_) => {
+            println!("Daemon is not running");
+        }
+    }
+
+    Ok(())
+}
+
+async fn stop_cmd(settings: &Settings) -> Result<()> {
+    let Ok(mut client) = connect_client(settings).await else {
+        println!("Daemon is not running");
+        return Ok(());
+    };
+
+    match client.shutdown().await {
+        Ok(true) => {
+            println!("Shutdown requested");
+
+            let pidfile_path = PathBuf::from(&settings.daemon.pidfile_path);
+            let timeout = Duration::from_secs(5);
+            match wait_for_pidfile_available(&pidfile_path, timeout).await {
+                Ok(()) => println!("Daemon stopped"),
+                Err(_) => println!("Daemon may still be shutting down"),
+            }
+
+            Ok(())
+        }
+        Ok(false) => bail!("Daemon rejected shutdown request"),
+        Err(err) => Err(err.wrap_err("Failed to send shutdown request")),
+    }
+}
+
+async fn run(settings: Settings, store: SqliteStore, history_db: ClientSqlite) -> Result<()> {
+    let pidfile_path = PathBuf::from(&settings.daemon.pidfile_path);
+    let _pidfile_guard = PidfileGuard::acquire(&pidfile_path)?;
+
+    turtle_daemon::boot(settings, store, history_db).await?;
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{
+        DAEMON_PROTOCOL_VERSION, DAEMON_VERSION, daemon_matches_expected, daemon_mismatch_message,
+    };
+
+    #[test]
+    fn test_version_matches() {
+        assert!(daemon_matches_expected(
+            DAEMON_VERSION,
+            DAEMON_PROTOCOL_VERSION
+        ));
+    }
+
+    #[test]
+    fn test_version_mismatch() {
+        assert!(!daemon_matches_expected("0.0.0", DAEMON_PROTOCOL_VERSION));
+        assert!(!daemon_matches_expected(DAEMON_VERSION, 999));
+        assert!(!daemon_matches_expected("0.0.0", 999));
+    }
+
+    #[test]
+    fn test_mismatch_message_version() {
+        let msg = daemon_mismatch_message("0.0.0", DAEMON_PROTOCOL_VERSION);
+        assert!(msg.contains("out of date"), "got: {msg}");
+        assert!(msg.contains("0.0.0"));
+        assert!(msg.contains(DAEMON_VERSION));
+    }
+
+    #[test]
+    fn test_mismatch_message_protocol() {
+        let msg = daemon_mismatch_message(DAEMON_VERSION, 999);
+        assert!(msg.contains("protocol mismatch"), "got: {msg}");
+    }
+}