//! The orphan sweep's two Docker-touching seams, against real containers.
//!
//! `sweep_orphans` force-removes containers. Its decision logic is pure and
//! unit-tested in `mission_runtime`, but the two calls that talk to Docker —
//! "which containers exist" and "does this checkout hold work no remote has" —
//! had never run against a daemon. Those are exactly the ones worth exercising
//! for real: the first decides what is considered at all, and the second is the
//! only thing standing between a reaper and ten unpushed commits.
//!
//! That is not hypothetical. The orphan that motivated this sweep held
//! +3451/-30 across 30 files on a branch that existed nowhere else.
//!
//! Skips cleanly when there is no Docker, so a machine or CI runner without one
//! reports "not run" rather than failing.

use cm_api::mission_runtime::{container_name, MissionRuntimeProvisioner, UnpushedWork};
use uuid::Uuid;

/// The image is already local on any machine that runs missions, and it has
/// `git`, which the probe needs.
const FIXTURE_IMAGE: &str = "clawmates-runtime:hooks";

/// These tests must not run at the same time as each other.
///
/// `sweep_orphans` is global: it reaps EVERY orphaned `cm-runtime-mission-*`
/// container on the daemon, which on a parallel test runner includes the
/// fixtures another test in this file just started. That is not a flaw in the
/// sweep — it is what a sweep is — but it means anything here that creates a
/// mission-shaped container has to hold this lock.
///
/// Found the honest way: the reap test deleted the listing test's fixture
/// mid-run and the listing test reported a container it could not see.
static FIXTURES: std::sync::LazyLock<tokio::sync::Mutex<()>> =
    std::sync::LazyLock::new(|| tokio::sync::Mutex::new(()));

fn docker_available() -> bool {
    std::process::Command::new("docker")
        .args(["image", "inspect", FIXTURE_IMAGE])
        .stdout(std::process::Stdio::null())
        .stderr(std::process::Stdio::null())
        .status()
        .map(|s| s.success())
        .unwrap_or(false)
}

/// Start a fixture container named like a mission runtime, running a shell
/// script that leaves `/mission/repo` in a known state.
fn start_fixture(id: Uuid, setup: &str) -> String {
    let name = container_name(id);
    let _ = std::process::Command::new("docker")
        .args(["rm", "-f", &name])
        .stdout(std::process::Stdio::null())
        .stderr(std::process::Stdio::null())
        .status();
    let script = format!("{setup}\nsleep 3600");
    let out = std::process::Command::new("docker")
        .args([
            "run", "-d", "--name", &name, "--entrypoint", "sh", FIXTURE_IMAGE, "-c", &script,
        ])
        .output()
        .expect("docker run");
    assert!(
        out.status.success(),
        "could not start fixture {name}: {}",
        String::from_utf8_lossy(&out.stderr)
    );
    // The script has to have finished its git work before the probe runs.
    std::thread::sleep(std::time::Duration::from_secs(3));
    name
}

fn remove(name: &str) {
    let _ = std::process::Command::new("docker")
        .args(["rm", "-f", name])
        .stdout(std::process::Stdio::null())
        .stderr(std::process::Stdio::null())
        .status();
}

const GIT_INIT: &str = "set -e
mkdir -p /mission/repo && cd /mission/repo
git init -q .
git config user.email t@t && git config user.name t
echo hello > a.txt && git add a.txt && git commit -qm 'work nobody else has'";

#[tokio::test]
async fn the_sweep_can_see_containers_and_refuses_the_ones_holding_work() {
    if !docker_available() {
        eprintln!("orphan_sweep: no docker or no {FIXTURE_IMAGE} — not run");
        return;
    }
    let Some(prov) = MissionRuntimeProvisioner::from_env() else {
        eprintln!("orphan_sweep: no docker connection — not run");
        return;
    };
    let _serial = FIXTURES.lock().await;

    let dirty_id = Uuid::now_v7();
    let clean_id = Uuid::now_v7();
    let empty_id = Uuid::now_v7();

    // Commits, and no remote ref anywhere: this is the container that must
    // survive. It is the one the real orphan looked like.
    let dirty = start_fixture(dirty_id, GIT_INIT);
    // The same repo, but every commit is reachable from a remote-tracking ref,
    // which is what "already pushed" looks like to `git rev-list --not
    // --remotes`.
    let clean = start_fixture(
        clean_id,
        &format!("{GIT_INIT}\ngit update-ref refs/remotes/origin/main HEAD"),
    );
    // No checkout at all — nothing to lose.
    let empty = start_fixture(empty_id, "set -e\nmkdir -p /root");

    let result = async {
        let names = prov.list_mission_containers().await?;
        let found: Vec<&String> = names.iter().map(|(n, _)| n).collect();
        for expected in [&dirty, &clean, &empty] {
            assert!(
                found.iter().any(|n| *n == expected),
                "the sweep cannot see {expected}; a container it cannot list is \
                 one it can never reap, which is the whole defect this closes. \
                 saw: {found:?}"
            );
        }

        // Docker's own creation timestamp must come back, or the sweep declines
        // to reap for want of an age.
        let (_, created) = names
            .iter()
            .find(|(n, _)| n == &dirty)
            .expect("dirty in listing");
        assert!(
            MissionRuntimeProvisioner::container_age(*created).is_some(),
            "a container docker will not date is never reaped, so an absent \
             timestamp here would silently disable the sweep"
        );

        match prov.unpushed_commits(&dirty).await {
            UnpushedWork::SomeOrUnknown(why) => {
                assert!(why.contains("no remote"), "{why}");
            }
            UnpushedWork::None => panic!(
                "the probe said a checkout with an unpushed commit holds nothing — \
                 this is the exact answer that destroys work"
            ),
        }

        assert_eq!(
            prov.unpushed_commits(&clean).await,
            UnpushedWork::None,
            "every commit is reachable from a remote ref, so there is nothing to lose"
        );
        assert_eq!(
            prov.unpushed_commits(&empty).await,
            UnpushedWork::None,
            "no /mission/repo at all means nothing to lose"
        );
        Ok::<(), String>(())
    }
    .await;

    remove(&dirty);
    remove(&clean);
    remove(&empty);
    result.expect("orphan sweep probes");
}

/// A container we cannot question is not a container we may delete.
#[tokio::test]
async fn a_container_that_is_gone_reads_as_holding_work() {
    if !docker_available() {
        eprintln!("orphan_sweep: no docker — not run");
        return;
    }
    let Some(prov) = MissionRuntimeProvisioner::from_env() else {
        return;
    };
    match prov
        .unpushed_commits("cm-runtime-mission-does-not-exist-at-all")
        .await
    {
        UnpushedWork::SomeOrUnknown(_) => {}
        UnpushedWork::None => panic!(
            "an unanswerable probe must never read as 'safe to delete' — every \
             failure path in this check is one-sided for that reason"
        ),
    }
}

/// Set to run the destructive sweep test.
///
/// The other tests in this file only create fixtures and read them. This one
/// calls `sweep_orphans`, which REMOVES containers — and CI runs
/// `cargo test --workspace` inside a container with `/var/run/docker.sock`
/// mounted, on gw04, which is the host that runs production missions.
///
/// `adopt_existing` protects everything already present, but it cannot protect
/// a mission container created in the seconds between that call and the sweep.
/// On a developer machine that race is nothing; on the production host it is a
/// mission. So the destructive test is opt-in, and CI simply does not run it.
const RUN_DESTRUCTIVE: &str = "CM_TEST_ORPHAN_SWEEP";

/// The reap decision itself, against real containers.
///
/// The probes above are the inputs; this is the act. A clean orphan past its
/// grace must go, an orphan holding unpushed work must stay, and a young one
/// must stay regardless — and all three have to be true of the same sweep, in
/// one pass, because that is how it runs.
#[tokio::test]
async fn the_sweep_reaps_the_clean_orphan_and_spares_the_others() {
    if !docker_available() {
        eprintln!("orphan_sweep: no docker — not run");
        return;
    }
    if std::env::var(RUN_DESTRUCTIVE).is_err() {
        eprintln!(
            "orphan_sweep: not run — this test removes containers, and the CI \
             runner shares a docker daemon with production. Set \
             {RUN_DESTRUCTIVE}=1 to run it."
        );
        return;
    }
    if MissionRuntimeProvisioner::from_env().is_none() {
        return;
    }
    let _serial = FIXTURES.lock().await;
    let pool = cm_testkit::test_pool().await;

    // Adopt every mission container that already exists on this daemon.
    //
    // The sweep asks the DATABASE whether a container is known, and a fresh
    // test database knows nothing — so on a developer machine the sweep
    // classifies the live local stack's mission containers as orphans and
    // reaps them. It did exactly that on the first run of this test, deleting
    // two real mission containers.
    //
    // Giving each a row makes the test safe AND covers the case the other
    // assertions do not: a container the platform still knows about is never
    // touched, whatever its checkout looks like.
    let adopted = adopt_existing(&pool).await;

    let clean_id = Uuid::now_v7();
    let dirty_id = Uuid::now_v7();
    let young_id = Uuid::now_v7();

    let alive = |name: &str| {
        std::process::Command::new("docker")
            .args(["inspect", name])
            .stdout(std::process::Stdio::null())
            .stderr(std::process::Stdio::null())
            .status()
            .map(|s| s.success())
            .unwrap_or(false)
    };

    let clean = start_fixture(
        clean_id,
        &format!("{GIT_INIT}\ngit update-ref refs/remotes/origin/main HEAD"),
    );
    let dirty = start_fixture(dirty_id, GIT_INIT);

    // Pass one, no grace: everything present is past its window, so the
    // decision is made purely on whether the checkout holds work.
    let swept = cm_api::mission_runtime::sweep_orphans(&pool, std::time::Duration::ZERO).await;
    let clean_gone = !alive(&clean);
    let dirty_alive = alive(&dirty);

    // Pass two, a real grace, on a container minted seconds ago. It is clean
    // and orphaned — reapable on every axis except its age — so if the grace is
    // decorative this is where that shows.
    //
    // Started AFTER the first pass on purpose: a grace applies to every
    // container in the sweep, so a fixture created before a zero-grace pass is
    // reaped by that pass and proves nothing about the window. The first
    // version of this test made exactly that mistake and failed itself.
    let young = start_fixture(
        young_id,
        &format!("{GIT_INIT}\ngit update-ref refs/remotes/origin/main HEAD"),
    );
    let swept2 =
        cm_api::mission_runtime::sweep_orphans(&pool, std::time::Duration::from_secs(3600)).await;
    let young_alive = alive(&young);

    remove(&clean);
    remove(&dirty);
    remove(&young);

    for name in &adopted {
        assert!(
            alive(name),
            "the sweep reaped {name}, which HAS a mission row — a container the \
             platform still knows about must never be touched"
        );
    }

    swept.expect("first sweep");
    swept2.expect("second sweep");
    assert!(
        clean_gone,
        "a clean orphan past its grace is exactly what this sweep exists to \
         reclaim; leaving it means the disk leak is still open"
    );
    assert!(
        dirty_alive,
        "an orphan holding commits no remote has MUST survive — the container \
         that motivated this held ten of them"
    );
    assert!(
        young_alive,
        "a container inside the grace window must be left alone even when it is \
         otherwise reapable, or the grace is decorative"
    );
}

/// Give every mission container already on this daemon a row, so the sweep
/// treats it as known and leaves it alone.
///
/// Returns the names, which then double as an assertion: none of them may be
/// reaped.
async fn adopt_existing(pool: &sqlx::PgPool) -> Vec<String> {
    let Some(prov) = MissionRuntimeProvisioner::from_env() else {
        return Vec::new();
    };
    let Ok(existing) = prov.list_mission_containers().await else {
        return Vec::new();
    };
    let ws = Uuid::now_v7();
    sqlx::query("INSERT INTO workspaces (id, name, plan) VALUES ($1, 'orphan-test', 'free')")
        .bind(ws)
        .execute(pool)
        .await
        .expect("seed workspace");
    let mut names = Vec::new();
    for (name, _) in existing {
        let Some(id) = cm_api::mission_runtime::mission_id_from_container(&name) else {
            continue;
        };
        sqlx::query(
            "INSERT INTO missions (id, workspace_id, title, template_kind)
             VALUES ($1, $2, 'adopted by orphan_sweep test', 'research_only')
             ON CONFLICT (id) DO NOTHING",
        )
        .bind(id)
        .bind(ws)
        .execute(pool)
        .await
        .expect("adopt container");
        names.push(name);
    }
    names
}