use common::io::read_string;
use common::request::Request;
use std::os::unix::fs::FileTypeExt;
use std::os::unix::net::UnixStream;
use std::path::PathBuf;
use std::process::{Child, Command};
use std::time::{Duration, Instant};

const PASSWORD_DIR: &str = concat!(env!("CARGO_MANIFEST_DIR"), "/../test_passwords");

fn temp_socket_path(tag: &str) -> PathBuf {
    let mut path = std::env::temp_dir();
    path.push(format!("saslauthd-{}-{}.sock", tag, std::process::id()));
    let _ = std::fs::remove_file(&path);
    path
}

/// A spawned daemon that is killed if the test panics before stopping it.
struct Daemon(Child);

impl Drop for Daemon {
    fn drop(&mut self) {
        if self.0.try_wait().ok().flatten().is_none() {
            let _ = self.0.kill();
            let _ = self.0.wait();
        }
    }
}

fn is_socket(path: &PathBuf) -> bool {
    std::fs::metadata(path)
        .map(|m| m.file_type().is_socket())
        .unwrap_or(false)
}

fn spawn_daemon(socket: &PathBuf) -> Daemon {
    let child = Command::new(env!("CARGO_BIN_EXE_saslauthd"))
        .arg("--socket-name")
        .arg(socket)
        .arg("--password-dir")
        .arg(PASSWORD_DIR)
        .spawn()
        .expect("failed to spawn saslauthd");

    let deadline = Instant::now() + Duration::from_secs(5);
    while !is_socket(socket) {
        assert!(Instant::now() < deadline, "daemon never created {socket:?}");
        std::thread::sleep(Duration::from_millis(10));
    }
    Daemon(child)
}

fn send_signal(daemon: &Daemon, signal: &str) {
    let child = &daemon.0;
    let status = Command::new("kill")
        .arg(format!("-{signal}"))
        .arg(child.id().to_string())
        .status()
        .expect("failed to run kill");
    assert!(status.success(), "kill -{signal} failed");
}

fn wait_for_exit(daemon: &mut Daemon, timeout: Duration) -> std::process::ExitStatus {
    let child = &mut daemon.0;
    let deadline = Instant::now() + timeout;
    loop {
        if let Some(status) = child.try_wait().expect("try_wait failed") {
            return status;
        }
        if Instant::now() >= deadline {
            let _ = child.kill();
            let _ = child.wait();
            panic!("daemon did not exit within {timeout:?}");
        }
        std::thread::sleep(Duration::from_millis(10));
    }
}

fn authenticate(socket: &PathBuf, password: &str) -> String {
    let mut stream = UnixStream::connect(socket).expect("connect to daemon");
    Request::new("bp", password, "imap", "")
        .write_to_stream(&mut stream)
        .expect("write request");
    read_string(&mut stream).expect("read response")
}

fn assert_clean_shutdown(signal: &str) {
    let socket = temp_socket_path(signal);
    let mut daemon = spawn_daemon(&socket);

    // Make sure the daemon actually works before we shut it down.
    assert_eq!(authenticate(&socket, "some-rad-password"), "OK");
    assert_eq!(authenticate(&socket, "wrong-password"), "NO");

    let started = Instant::now();
    send_signal(&daemon, signal);
    let status = wait_for_exit(&mut daemon, Duration::from_secs(1));

    assert!(status.success(), "expected exit status 0 on {signal}, got {status}");
    assert!(
        started.elapsed() < Duration::from_secs(1),
        "shutdown took {:?}",
        started.elapsed()
    );
    assert!(!socket.exists(), "socket file {socket:?} was left behind");
}

#[test]
fn it_shuts_down_cleanly_on_sigterm() {
    assert_clean_shutdown("TERM");
}

#[test]
fn it_shuts_down_cleanly_on_sigint() {
    assert_clean_shutdown("INT");
}

#[test]
fn it_recreates_a_stale_socket_on_startup() {
    let socket = temp_socket_path("stale");
    std::fs::write(&socket, b"stale").expect("create stale socket file");

    let mut daemon = spawn_daemon(&socket);
    assert_eq!(authenticate(&socket, "some-rad-password"), "OK");

    send_signal(&daemon, "TERM");
    let status = wait_for_exit(&mut daemon, Duration::from_secs(1));
    assert!(status.success());
    assert!(!socket.exists());
}