ralph-agent-loop 0.3.1

//! Daemon stop command implementation.
//!
//! Responsibilities:
//! - Stop a running Ralph daemon process gracefully.
//! - Clean up daemon state and lock files after stopping.
//! - Handle cases where daemon is not running or state is stale.
//!
//! Non-scope:
//! - Starting or restarting the daemon (handled by start command).
//! - Windows service management (Unix-only implementation).
//!
//! Invariants/assumptions:
//! - Daemon uses a dedicated lock at `.ralph/cache/daemon.lock`.
//! - Daemon state is stored at `.ralph/cache/daemon.json`.
//! - Stop signal is created via `crate::signal::create_stop_signal`.

use crate::config::Resolved;
use crate::lock::PidLiveness;
use anyhow::{Context, Result, bail};
use std::fs;
use std::time::Duration;

use super::{
    DAEMON_LOCK_DIR, DAEMON_STATE_FILE, daemon_pid_liveness, get_daemon_state,
    manual_daemon_cleanup_instructions,
};

/// Stop the daemon gracefully.
pub fn stop(resolved: &Resolved) -> Result<()> {
    let cache_dir = resolved.repo_root.join(".ralph/cache");

    // Check if daemon is running
    let state = match get_daemon_state(&cache_dir)? {
        Some(state) => state,
        None => {
            println!("Daemon is not running");
            return Ok(());
        }
    };

    match daemon_pid_liveness(state.pid) {
        PidLiveness::NotRunning => {
            println!("Daemon is not running (removing stale state file)");
            let state_path = cache_dir.join(DAEMON_STATE_FILE);
            if let Err(e) = fs::remove_file(&state_path) {
                log::debug!(
                    "Failed to remove stale daemon state file {}: {}",
                    state_path.display(),
                    e
                );
            }
            let lock_path = cache_dir.join(DAEMON_LOCK_DIR);
            if let Err(e) = fs::remove_dir_all(&lock_path) {
                log::debug!(
                    "Failed to remove stale daemon lock dir {}: {}",
                    lock_path.display(),
                    e
                );
            }
            return Ok(());
        }
        PidLiveness::Indeterminate => {
            bail!(
                "Daemon PID {} liveness is indeterminate; preserving state/lock to avoid concurrent supervisors. \
                 {}",
                state.pid,
                manual_daemon_cleanup_instructions(&cache_dir)
            );
        }
        PidLiveness::Running => {}
    }

    // Create stop signal
    crate::signal::create_stop_signal(&cache_dir).context("Failed to create stop signal")?;
    println!("Stop signal sent to daemon (PID: {})", state.pid);

    // Wait up to 10 seconds for the daemon to exit
    println!("Waiting for daemon to stop...");
    for _ in 0..100 {
        std::thread::sleep(Duration::from_millis(100));
        if matches!(daemon_pid_liveness(state.pid), PidLiveness::NotRunning) {
            println!("Daemon stopped successfully");
            let state_path = cache_dir.join(DAEMON_STATE_FILE);
            if let Err(e) = fs::remove_file(&state_path) {
                log::debug!(
                    "Failed to remove daemon state file after stop {}: {}",
                    state_path.display(),
                    e
                );
            }
            return Ok(());
        }
    }

    // Daemon didn't stop in time
    bail!(
        "Daemon did not stop within 10 seconds. PID: {}. You may need to kill it manually with `kill -9 {}`",
        state.pid,
        state.pid
    );
}