//! Group and per-process accounting: stats(), sample_stats(), profile(), and
//! the per-process diagnostics — `stats`-gated via the `mod` declaration in
//! `main.rs`.

use std::time::Duration;

use processkit::{Mechanism, ProcessGroup};

use crate::common::*;

#[tokio::test]
#[ignore = "creates an OS job/cgroup and reads accounting"]
async fn group_stats_report_active_processes() {
    let group = ProcessGroup::new().expect("create group");
    if matches!(group.mechanism(), Mechanism::None) {
        // No containment → stats() honestly reports zero live processes.
        eprintln!("skipping: no containment on this target");
        return;
    }
    let _process = group.start(&sleeper()).await.expect("spawn sleeper");
    let stats = group.stats().expect("stats");
    assert!(
        stats.active_process_count >= 1,
        "expected a live process, got {stats:?}"
    );
}

#[tokio::test]
#[ignore = "spawns a real subprocess and reads per-process metrics"]
async fn process_diagnostics_are_available() {
    // On the containment platforms CPU/memory are reported; elsewhere they may be
    // None, so only assert the pid/elapsed basics universally.
    let mut process = sleeper().start().await.expect("start sleeper");
    assert!(process.pid().is_some());
    assert!(process.elapsed() < Duration::from_secs(5));
    if cfg!(any(windows, target_os = "linux")) {
        // Give the child a moment to accrue something measurable.
        tokio::time::sleep(Duration::from_millis(100)).await;
        assert!(
            process.peak_memory_bytes().is_some(),
            "peak memory should be readable on this platform"
        );
    }
    let _ = process.standard_input(); // no-op (stdin not kept open)
    drop(process);
}

#[tokio::test]
#[ignore = "spawns a real subprocess and samples the group's stats"]
async fn sample_stats_yields_a_live_series() {
    use tokio_stream::StreamExt;

    let group = ProcessGroup::new().expect("create group");
    if matches!(group.mechanism(), Mechanism::None) {
        eprintln!("skipping: no containment on this target");
        return;
    }
    let _child = group.start(&sleeper()).await.expect("start sleeper");

    let mut samples = group.sample_stats(Duration::from_millis(50));
    for n in 0..3 {
        let snapshot = tokio::time::timeout(Duration::from_secs(5), samples.next())
            .await
            .expect("sample in time")
            .expect("series still live");
        assert!(
            snapshot.active_process_count >= 1,
            "sample #{n} saw no live process: {snapshot:?}"
        );
    }
}

#[tokio::test]
#[ignore = "spawns a real subprocess and profiles its run"]
async fn profile_summarizes_a_run() {
    let profile = group_started_short_run()
        .await
        .profile(Duration::from_millis(50))
        .await
        .expect("profile");

    assert_eq!(profile.exit_code, Some(0), "profile: {profile:?}");
    assert!(
        profile.duration >= Duration::from_millis(500),
        "a ~1s child reported {:?}",
        profile.duration
    );
    assert!(profile.samples >= 1, "profile never sampled: {profile:?}");
    if cfg!(any(windows, target_os = "linux")) {
        assert!(
            profile.peak_memory_bytes.is_some(),
            "peak RSS should be readable on this platform: {profile:?}"
        );
    }
}

/// Start a ~1s single-process child directly (its own private group).
async fn group_started_short_run() -> processkit::RunningProcess {
    sleep_secs(1).start().await.expect("start short child")
}
