trusty-memory 0.1.56

//! Handler for `trusty-memory service` (macOS launchd integration).
//!
//! Why: launchd is the canonical way to keep a long-lived foreground daemon
//! alive on macOS — it survives logout, restarts on crash, and integrates with
//! `launchctl` for diagnostics. Wrapping the plist mechanics in `service`
//! subcommands keeps users from having to hand-edit XML. This mirrors the
//! pattern used by `trusty-search service`, sharing the
//! [`trusty_common::launchd`] implementation so the two tools cannot drift.
//! What: macOS routes to `service_install` / `service_start` / `service_stop`
//! / `service_logs`. Non-macOS prints a "not supported" error and exits 1.
//! Test: on Linux, every action returns Err with the platform message; on
//! macOS, `service install` writes the plist without loading it, `start`
//! bootstraps it, `stop` boots it out, and `logs` tails the log files.

use anyhow::Result;
use clap::Subcommand;
#[cfg(target_os = "macos")]
use colored::Colorize;

/// Subcommands for `trusty-memory service` (macOS launchd integration).
///
/// Why: the four lifecycle actions (install, start, stop, logs) are the
/// minimum surface needed to manage a launchd-backed daemon without
/// hand-editing plists or shelling out to `launchctl` directly.
/// What: a clap-derived enum dispatched by [`handle_service`].
/// Test: clap's `--help` enumerates all four; integration via
/// `cargo run -p trusty-memory -- service --help`.
#[derive(Debug, Clone, Subcommand)]
pub enum ServiceAction {
    /// Install the LaunchAgent plist (does not load it).
    Install,
    /// Install and load the LaunchAgent (start the daemon).
    Start,
    /// Unload the LaunchAgent (stop the daemon).
    Stop,
    /// Tail the launchd stdout / stderr logs.
    Logs,
}

/// Reverse-DNS label for the LaunchAgent.
///
/// Why: launchd identifies agents by their `Label`, which must also be the
/// plist filename's stem. Centralising the constant keeps install / start /
/// stop in lockstep.
/// What: `com.trusty.memory` — matches the naming convention used by
/// `trusty-search` (`com.trusty.trusty-search`) and follows reverse-DNS.
/// Test: covered indirectly by `service install` integration runs.
#[cfg(target_os = "macos")]
pub const LAUNCHD_LABEL: &str = "com.trusty.memory";

/// Dispatch a `trusty-memory service <action>` invocation.
///
/// Why: the binary's `main.rs` should not contain `#[cfg]` blocks — it
/// always calls this function and lets the module decide what is and isn't
/// supported on the current platform.
/// What: on macOS, dispatches to the per-action helper. On every other
/// platform, returns an error with a friendly message pointing operators to
/// their native service manager.
/// Test: on Linux CI, asserts the Err message contains "not supported".
pub fn handle_service(action: &ServiceAction) -> Result<()> {
    #[cfg(target_os = "macos")]
    {
        match action {
            ServiceAction::Install => service_install(),
            ServiceAction::Start => service_start(),
            ServiceAction::Stop => service_stop(),
            ServiceAction::Logs => service_logs(),
        }
    }
    #[cfg(not(target_os = "macos"))]
    {
        let _ = action;
        anyhow::bail!(
            "`trusty-memory service` is not supported on this platform — \
             use your distro's service manager (systemd, OpenRC, etc.) directly."
        );
    }
}

/// Resolve the log directory for the launchd-managed daemon.
///
/// Why: launchd writes `stdout` and `stderr` to files we declare in the
/// plist, and they need a real directory before the daemon can start.
/// Centralising the path keeps install / logs in agreement.
/// What: `<data_dir>/trusty-memory/logs`, where `<data_dir>` comes from
/// `dirs::data_dir()` (`~/Library/Application Support` on macOS). Creates
/// the directory if it does not already exist.
/// Test: covered indirectly by `service install` integration runs.
#[cfg(target_os = "macos")]
pub(crate) fn launchd_log_dir() -> Result<std::path::PathBuf> {
    let data =
        dirs::data_dir().ok_or_else(|| anyhow::anyhow!("could not resolve user data directory"))?;
    let dir = data.join("trusty-memory").join("logs");
    std::fs::create_dir_all(&dir)
        .map_err(|e| anyhow::anyhow!("create log dir {}: {e}", dir.display()))?;
    Ok(dir)
}

/// Build the shared `LaunchdConfig` describing the trusty-memory agent.
///
/// Why: install / start / stop all need the same plist label, log paths,
/// and arg vector. Building it in one place keeps them in sync and lets the
/// shared [`trusty_common::launchd`] module own the XML rendering and the
/// `launchctl` glue.
/// What: assembles a [`trusty_common::launchd::LaunchdConfig`] pointing at
/// the current binary with `serve` as the single argument; uses
/// `KeepAlive::OnSuccess` so a clean shutdown does not crash-loop.
/// Test: exercised via `service install` and `service start`.
#[cfg(target_os = "macos")]
pub(crate) fn build_launchd_config(
    exe: std::path::PathBuf,
    log_dir: std::path::PathBuf,
) -> trusty_common::launchd::LaunchdConfig {
    use trusty_common::launchd::{KeepAlive, LaunchdConfig};
    LaunchdConfig {
        label: LAUNCHD_LABEL.to_string(),
        exe_path: exe,
        args: vec!["serve".to_string()],
        log_dir,
        keep_alive: KeepAlive::OnSuccess,
        throttle_interval: 10,
        env_vars: vec![],
    }
}

#[cfg(target_os = "macos")]
fn current_exe() -> Result<std::path::PathBuf> {
    std::env::current_exe().map_err(|e| anyhow::anyhow!("could not resolve current exe: {e}"))
}

/// `service install` — write the plist without loading it.
///
/// Why: operators sometimes want to inspect or hand-edit the plist before
/// launchd takes ownership. Splitting "install" from "start" gives them that
/// window without forcing a stop-start dance.
/// What: resolves the binary path and log directory, then calls
/// `LaunchdConfig::install()` which writes `~/Library/LaunchAgents/<label>.plist`
/// and creates the log directory. Does not call `bootstrap`.
/// Test: integration via `cargo run -p trusty-memory -- service install`.
#[cfg(target_os = "macos")]
fn service_install() -> Result<()> {
    let exe = current_exe()?;
    let log_dir = launchd_log_dir()?;
    let cfg = build_launchd_config(exe, log_dir.clone());
    let plist_path = cfg.plist_path()?;
    cfg.install()?;
    println!(
        "{} Wrote LaunchAgent plist: {}",
        "✓".green(),
        plist_path.display()
    );
    println!(
        "  Logs:    {}\n  Start:   {}",
        log_dir.display().to_string().dimmed(),
        "trusty-memory service start".cyan(),
    );
    Ok(())
}

/// `service start` — install the plist (if needed) and bootstrap the agent.
///
/// Why: the common "I want it running" path should be one command, not two.
/// `install` + `bootstrap` is idempotent under the shared launchd module
/// (bootstrap calls bootout first), so calling start repeatedly is safe.
/// What: writes the plist via `install()`, then loads it into the user's
/// `gui/<uid>` domain via `bootstrap()`. The agent will start immediately
/// and restart on non-zero exits per `KeepAlive::OnSuccess`.
/// Test: integration via `cargo run -p trusty-memory -- service start`.
#[cfg(target_os = "macos")]
fn service_start() -> Result<()> {
    let exe = current_exe()?;
    let log_dir = launchd_log_dir()?;
    let cfg = build_launchd_config(exe, log_dir.clone());
    let plist_path = cfg.plist_path()?;
    cfg.install()?;
    println!(
        "{} Wrote LaunchAgent plist: {}",
        "✓".green(),
        plist_path.display()
    );

    cfg.bootstrap()?;
    let domain = format!("gui/{}", trusty_common::launchd::current_uid());
    println!(
        "{} Loaded {} into {} — daemon will start automatically.",
        "✓".green(),
        LAUNCHD_LABEL,
        domain
    );
    println!(
        "  Logs:    {}\n  Stop:    {}",
        log_dir.display().to_string().dimmed(),
        "trusty-memory service stop".cyan(),
    );
    Ok(())
}

/// `service stop` — boot out the agent (stop and unload).
///
/// Why: operators need a friendly counterpart to `start` that does not
/// require remembering the full `launchctl bootout gui/<uid>/<label>`
/// invocation. The shared launchd module treats "not loaded" as success, so
/// calling stop on an unloaded agent is also a no-op.
/// What: builds the same config used by `start`, then calls `bootout()`.
/// Leaves the plist file in place — re-`start` will reload it.
/// Test: integration via `cargo run -p trusty-memory -- service stop`.
#[cfg(target_os = "macos")]
fn service_stop() -> Result<()> {
    let exe = current_exe()?;
    let log_dir = launchd_log_dir()?;
    let cfg = build_launchd_config(exe, log_dir);
    cfg.bootout()?;
    println!(
        "{} Unloaded {} (plist file preserved at {}).",
        "✓".green(),
        LAUNCHD_LABEL,
        cfg.plist_path()?.display().to_string().dimmed()
    );
    Ok(())
}

/// `service logs` — tail the launchd stdout/stderr log files.
///
/// Why: launchd routes the daemon's stdout/stderr to plain files; a friendly
/// `tail -F` wrapper avoids forcing operators to remember the path.
/// What: resolves the log directory and execs `tail -F <stdout> <stderr>`.
/// Emits a hint when neither file exists yet (daemon never started).
/// Test: side-effecting; covered manually via
/// `cargo run -p trusty-memory -- service logs`.
#[cfg(target_os = "macos")]
fn service_logs() -> Result<()> {
    let log_dir = launchd_log_dir()?;
    let stdout = log_dir.join("stdout.log");
    let stderr = log_dir.join("stderr.log");
    if !stdout.exists() && !stderr.exists() {
        eprintln!(
            "{} No logs at {} yet — start the service first ({}).",
            "·".dimmed(),
            log_dir.display(),
            "trusty-memory service start".cyan()
        );
        return Ok(());
    }
    let status = std::process::Command::new("tail")
        .arg("-F")
        .arg(&stdout)
        .arg(&stderr)
        .status()
        .map_err(|e| anyhow::anyhow!("tail failed: {e}"))?;
    if !status.success() {
        anyhow::bail!("tail exited with {status}");
    }
    Ok(())
}

#[cfg(test)]
mod tests {
    use super::*;

    /// Why: on non-macOS platforms, every `service` action must surface a
    /// clear, actionable error instead of silently succeeding or panicking.
    /// What: invokes `handle_service` with each action and asserts the Err
    /// message contains the "not supported" sentinel.
    /// Test: macOS skips this (the actions perform real `launchctl` work).
    #[cfg(not(target_os = "macos"))]
    #[test]
    fn handle_service_errors_on_unsupported_platform() {
        for action in [
            ServiceAction::Install,
            ServiceAction::Start,
            ServiceAction::Stop,
            ServiceAction::Logs,
        ] {
            let err = handle_service(&action).expect_err("must fail on non-macOS");
            let msg = format!("{err}");
            assert!(
                msg.contains("not supported"),
                "expected platform error, got: {msg}"
            );
        }
    }

    /// Why: the LaunchdConfig we hand to `trusty_common::launchd` must always
    /// describe the canonical trusty-memory agent (label, args, restart
    /// policy). Drift here corrupts every plist that the binary writes.
    /// What: builds the config with dummy paths and asserts the
    /// load-bearing fields.
    /// Test: pure construction, no fs side effects.
    #[cfg(target_os = "macos")]
    #[test]
    fn build_launchd_config_uses_canonical_shape() {
        use std::path::PathBuf;
        use trusty_common::launchd::KeepAlive;

        let cfg = build_launchd_config(
            PathBuf::from("/usr/local/bin/trusty-memory"),
            PathBuf::from("/tmp/trusty-memory/logs"),
        );
        assert_eq!(cfg.label, LAUNCHD_LABEL);
        assert_eq!(cfg.args, vec!["serve".to_string()]);
        assert_eq!(cfg.keep_alive, KeepAlive::OnSuccess);
        assert_eq!(cfg.throttle_interval, 10);
        assert!(cfg.env_vars.is_empty());
    }
}