swapdex 0.167.16

//! Renewing a lapsed access token, end to end.
//!
//! The failure paths are covered by unit tests and were seen against the real
//! endpoint; the SUCCESS path had never been executed, because it needs an
//! account that is idle AND holds a refresh token the server still honours, and
//! there was not one to spare. This runs the whole path against a token endpoint
//! of our own: the request swapdex builds, the answer it merges, and the
//! credential it writes back.

use std::process::Command;
use std::sync::{Arc, Mutex};

fn bin() -> &'static str {
    env!("CARGO_BIN_EXE_swapdex")
}

/// A token endpoint that records what it was asked and answers with new tokens.
fn fake_oauth(sink: Arc<Mutex<Vec<String>>>, response: &'static str) -> String {
    let server = tiny_http::Server::http("127.0.0.1:0").unwrap();
    let port = server.server_addr().to_ip().unwrap().port();
    std::thread::spawn(move || {
        for mut rq in server.incoming_requests() {
            let mut body = String::new();
            std::io::Read::read_to_string(rq.as_reader(), &mut body).ok();
            sink.lock().unwrap().push(body);
            let _ = rq.respond(tiny_http::Response::from_string(response));
        }
    });
    format!("http://127.0.0.1:{port}/v1/oauth/token")
}

/// A login server that refuses every refresh with `status`.
fn refusing_oauth(sink: Arc<Mutex<Vec<String>>>, status: u16, body: &'static str) -> String {
    let server = tiny_http::Server::http("127.0.0.1:0").unwrap();
    let port = server.server_addr().to_ip().unwrap().port();
    std::thread::spawn(move || {
        for mut rq in server.incoming_requests() {
            let mut seen = String::new();
            std::io::Read::read_to_string(rq.as_reader(), &mut seen).ok();
            sink.lock().unwrap().push(seen);
            let _ = rq.respond(tiny_http::Response::from_string(body).with_status_code(status));
        }
    });
    format!("http://127.0.0.1:{port}/v1/oauth/token")
}

/// A Claude account whose access token lapsed an hour ago and whose refresh
/// token is still good - the state every idle account reaches.
fn seed_lapsed_account(root: &std::path::Path, name: &str, id: &str) -> std::path::PathBuf {
    let store = root.join(".local/share/swapdex");
    let slot = store.join("slots").join(id);
    std::fs::create_dir_all(&slot).unwrap();
    let now_ms = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .unwrap()
        .as_millis() as i64;
    std::fs::write(
        slot.join(".credentials.json"),
        format!(
            r#"{{"claudeAiOauth":{{"accessToken":"OLD-AT","refreshToken":"OLD-RT",
               "expiresAt":{},"refreshTokenExpiresAt":{},"subscriptionType":"max",
               "scopes":["user:inference"]}},"mcpOAuth":{{"keep":"me"}}}}"#,
            now_ms - 3_600_000,
            now_ms + 30 * 86_400_000
        ),
    )
    .unwrap();
    std::fs::write(
        slot.join(".claude.json"),
        format!(r#"{{"oauthAccount":{{"accountUuid":"u-{name}","emailAddress":"{name}@x.com"}}}}"#),
    )
    .unwrap();
    std::fs::write(
        store.join("slots.json"),
        serde_json::to_vec(&serde_json::json!([{
            "name": name, "id": id, "config_dir": slot, "adopted": false,
            "tool": "claude-code"
        }]))
        .unwrap(),
    )
    .unwrap();
    slot
}

fn credential(slot: &std::path::Path) -> serde_json::Value {
    let bytes = std::fs::read(slot.join(".credentials.json")).unwrap();
    serde_json::from_slice(&bytes).unwrap()
}

#[test]
fn a_lapsed_account_is_renewed_in_place() {
    let root = tempfile::tempdir().unwrap();
    let slot = seed_lapsed_account(root.path(), "work", "aaaa1111");
    let asked = Arc::new(Mutex::new(Vec::new()));
    let url = fake_oauth(
        asked.clone(),
        r#"{"access_token":"NEW-AT","refresh_token":"NEW-RT","expires_in":3600}"#,
    );

    let out = Command::new(bin())
        .args(["refresh", "work"])
        .env("SWAPDEX_ROOT", root.path())
        .env("SWAPDEX_OAUTH_URL", &url)
        .env("HOME", root.path())
        .output()
        .unwrap();
    let said =
        String::from_utf8_lossy(&out.stdout).into_owned() + &String::from_utf8_lossy(&out.stderr);
    assert!(said.contains("work renewed"), "reported success: {said}");

    // What swapdex asked for.
    let body = asked.lock().unwrap().first().cloned().expect("one request");
    let req: serde_json::Value = serde_json::from_str(&body).expect("json body");
    assert_eq!(req["grant_type"], "refresh_token");
    assert_eq!(req["refresh_token"], "OLD-RT", "the token it held");
    assert!(req["client_id"].is_string(), "the client is named: {body}");

    // What it wrote back. The new refresh token REPLACES the old one: the server
    // retires what it just spent, and keeping it would leave the account unable
    // to renew the time after this.
    let c = credential(&slot);
    let o = &c["claudeAiOauth"];
    assert_eq!(o["accessToken"], "NEW-AT");
    assert_eq!(o["refreshToken"], "NEW-RT");
    assert_eq!(o["subscriptionType"], "max", "untouched fields survive");
    assert_eq!(
        c["mcpOAuth"]["keep"], "me",
        "and so does the rest of the file"
    );

    // The expiry is an absolute moment in the future, not the seconds it was sent.
    let now_ms = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .unwrap()
        .as_millis() as i64;
    let exp = o["expiresAt"].as_i64().expect("an expiry");
    assert!(
        exp > now_ms && exp <= now_ms + 3_600_000,
        "an hour ahead, not 3600: {exp}"
    );

    // And the account now reads as current rather than expired.
    let after = Command::new(bin())
        .args(["refresh", "work"])
        .env("SWAPDEX_ROOT", root.path())
        .env("SWAPDEX_OAUTH_URL", &url)
        .env("HOME", root.path())
        .output()
        .unwrap();
    assert!(
        String::from_utf8_lossy(&after.stdout).contains("already current"),
        "a renewed account is not renewed again: {:?}",
        String::from_utf8_lossy(&after.stdout)
    );
    assert_eq!(
        asked.lock().unwrap().len(),
        1,
        "and no second request was made"
    );
}

// A server that renews the access token without issuing a new refresh token:
// dropping the old one would leave the account unable to renew ever again.
#[test]
fn a_renewal_without_a_new_refresh_token_keeps_the_old_one() {
    let root = tempfile::tempdir().unwrap();
    let slot = seed_lapsed_account(root.path(), "work", "bbbb2222");
    let asked = Arc::new(Mutex::new(Vec::new()));
    let url = fake_oauth(
        asked.clone(),
        r#"{"access_token":"NEW-AT","expires_in":3600}"#,
    );

    let out = Command::new(bin())
        .args(["refresh", "work"])
        .env("SWAPDEX_ROOT", root.path())
        .env("SWAPDEX_OAUTH_URL", &url)
        .env("HOME", root.path())
        .output()
        .unwrap();
    assert!(String::from_utf8_lossy(&out.stdout).contains("renewed"));
    let o = credential(&slot);
    assert_eq!(o["claudeAiOauth"]["accessToken"], "NEW-AT");
    assert_eq!(o["claudeAiOauth"]["refreshToken"], "OLD-RT");
}

// A refusal must leave the credential exactly as it was: half-writing one is how
// an account becomes unusable without anybody touching it.
#[test]
fn a_refused_renewal_changes_nothing() {
    let root = tempfile::tempdir().unwrap();
    let slot = seed_lapsed_account(root.path(), "work", "cccc3333");
    let before = std::fs::read(slot.join(".credentials.json")).unwrap();
    let asked = Arc::new(Mutex::new(Vec::new()));
    let url = fake_oauth(asked.clone(), r#"{"error":"invalid_grant"}"#);

    let out = Command::new(bin())
        .args(["refresh", "work"])
        .env("SWAPDEX_ROOT", root.path())
        .env("SWAPDEX_OAUTH_URL", &url)
        .env("HOME", root.path())
        .output()
        .unwrap();
    let said = String::from_utf8_lossy(&out.stdout).into_owned();
    assert_eq!(
        out.status.code(),
        Some(4),
        "failed renewal must fail the command: {said}"
    );
    assert!(
        said.contains("could not be renewed"),
        "the refusal is reported: {said}"
    );
    assert_eq!(
        std::fs::read(slot.join(".credentials.json")).unwrap(),
        before,
        "the credential is untouched"
    );
}

/// The keep-alive sweep is the answer to accounts that die of neglect. An OAuth
/// refresh token rotates when it is used; leave an account alone long enough and
/// only a browser sign-in brings it back. Three accounts on the machine this was
/// written for died exactly that way and stayed dead for a week.
///
/// So the sweep renews AHEAD of the refresh token's end, and it must reach an
/// account nobody is using, which is the one at risk. It does NOT renew because
/// the ACCESS token is about to lapse: every renewal rotates the refresh token,
/// and one renewed two hours after the last - which that rule did to
/// eight-hour tokens - was stranded by a login server that processed it and
/// answered 503.
#[test]
fn keep_alive_renews_by_the_refresh_tokens_end_not_the_access_tokens() {
    let root = tempfile::tempdir().unwrap();
    let slot = seed_lapsed_account(root.path(), "idle", "aaaa1111");
    // Still VALID, a couple of hours from expiry: the state `swapdex refresh`
    // leaves alone. What decides a keep-alive is the refresh token's end.
    let now_ms = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .unwrap()
        .as_millis() as i64;
    let write = |refresh_end: i64| {
        std::fs::write(
            slot.join(".credentials.json"),
            format!(
                r#"{{"claudeAiOauth":{{"accessToken":"OLD-AT","refreshToken":"OLD-RT",
                   "expiresAt":{},"refreshTokenExpiresAt":{}}}}}"#,
                now_ms + 2 * 3_600_000,
                refresh_end
            ),
        )
        .unwrap();
    };

    let asked = Arc::new(Mutex::new(Vec::new()));
    let url = fake_oauth(
        asked.clone(),
        r#"{"access_token":"NEW-AT","refresh_token":"NEW-RT","expires_in":3600}"#,
    );
    let sweep = || {
        let out = Command::new(bin())
            .args(["refresh", "--keep-alive"])
            .env("SWAPDEX_ROOT", root.path())
            .env("SWAPDEX_OAUTH_URL", &url)
            .output()
            .unwrap();
        format!(
            "{}{}",
            String::from_utf8_lossy(&out.stdout),
            String::from_utf8_lossy(&out.stderr)
        )
    };

    // Two hours of access left, weeks of refresh token: nothing to renew.
    write(now_ms + 30 * 86_400_000);
    let said = sweep();
    assert_eq!(
        asked.lock().unwrap().len(),
        0,
        "a refresh token weeks from its end was rotated anyway: {said}"
    );
    // Two days from the refresh token's end: renewed, once.
    write(now_ms + 2 * 86_400_000);
    let said = sweep();
    assert_eq!(
        asked.lock().unwrap().len(),
        1,
        "a refresh token near its end was not renewed: {said}"
    );
    let after = std::fs::read_to_string(slot.join(".credentials.json")).unwrap();
    assert!(
        after.contains("NEW-AT"),
        "the renewed token was written: {after}"
    );
    assert!(
        after.contains("NEW-RT"),
        "and the rotated refresh token replaced the spent one: {after}"
    );
    assert!(
        said.contains("idle"),
        "it says which account it renewed: {said}"
    );
}

/// A Codex slot whose access token lapsed and whose refresh token is still good.
///
/// Measured on two real machines: a slot's access token expires exactly ten days
/// after its last renewal, Codex only renews when Codex RUNS, and four of eight
/// slots were already dead. Nothing in swapdex could renew one - `refresh_slot`
/// reads Claude's credential shape, so it answered "no credential" and did
/// nothing, silently.
fn seed_lapsed_codex(root: &std::path::Path, name: &str, id: &str) -> std::path::PathBuf {
    let store = root.join(".local/share/swapdex");
    let slot = store.join("slots").join(id);
    std::fs::create_dir_all(&slot).unwrap();
    // A JWT that expired an hour ago: header.payload.sig, payload carrying `exp`.
    let now = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .unwrap()
        .as_secs() as i64;
    let b64 = |s: &str| {
        use base64::Engine;
        base64::engine::general_purpose::URL_SAFE_NO_PAD.encode(s)
    };
    let lapsed = format!(
        "{}.{}.sig",
        b64(r#"{"alg":"none"}"#),
        b64(&format!(r#"{{"exp":{}}}"#, now - 3_600))
    );
    std::fs::write(
        slot.join("auth.json"),
        serde_json::to_vec_pretty(&serde_json::json!({
            "auth_mode": "chatgpt",
            "OPENAI_API_KEY": serde_json::Value::Null,
            "tokens": {
                "id_token": "OLD-ID", "access_token": lapsed,
                "refresh_token": "OLD-RT", "account_id": "acct-1"
            },
            "last_refresh": "2026-08-19T07:41:56Z"
        }))
        .unwrap(),
    )
    .unwrap();
    std::fs::write(
        store.join("slots.json"),
        serde_json::to_vec(&serde_json::json!([{
            "name": name, "id": id, "config_dir": slot, "adopted": false, "tool": "codex"
        }]))
        .unwrap(),
    )
    .unwrap();
    slot
}

fn codex_auth(slot: &std::path::Path) -> serde_json::Value {
    serde_json::from_slice(&std::fs::read(slot.join("auth.json")).unwrap()).unwrap()
}

#[cfg(target_os = "linux")]
struct ReapedChild(std::process::Child);

#[cfg(target_os = "linux")]
impl Drop for ReapedChild {
    fn drop(&mut self) {
        let _ = self.0.kill();
        let _ = self.0.wait();
    }
}

/// Run a harmless process whose name and config environment look exactly like
/// one tool session. Its config lives under the test root, so refresh safety
/// can inspect a fake identity without ever following `/proc` into a real auth
/// file.
#[cfg(target_os = "linux")]
fn running_tool(root: &std::path::Path, tool: &str, config_dir: &std::path::Path) -> ReapedChild {
    let bin = root.join(format!("fake-{tool}")).join(tool);
    std::fs::create_dir_all(bin.parent().unwrap()).unwrap();
    // exec preserves this link's basename as the process name. Reusing the
    // system executable avoids ETXTBSY from executing a just-copied fixture
    // while other test threads are spawning children.
    let sleep = if std::path::Path::new("/bin/sleep").exists() {
        "/bin/sleep"
    } else {
        "/usr/bin/sleep"
    };
    std::os::unix::fs::symlink(sleep, &bin).unwrap();

    let config_var = if tool == "claude" {
        "CLAUDE_CONFIG_DIR"
    } else {
        "CODEX_HOME"
    };
    let mut child = std::process::Command::new(&bin)
        .arg("30")
        .env("HOME", root)
        .env(config_var, config_dir)
        .spawn()
        .unwrap();
    let environ = format!("/proc/{}/environ", child.id());
    for _ in 0..300 {
        if std::fs::read(&environ).is_ok_and(|b| {
            String::from_utf8_lossy(&b)
                .contains(&format!("{config_var}={}", config_dir.to_string_lossy()))
        }) {
            return ReapedChild(child);
        }
        std::thread::sleep(std::time::Duration::from_millis(10));
    }
    let _ = child.kill();
    let _ = child.wait();
    panic!("the fake {tool} process never exposed its isolated environment");
}

#[cfg(target_os = "linux")]
fn seed_external_identity(dir: &std::path::Path, tool: &str, account: &str) {
    std::fs::create_dir_all(dir).unwrap();
    if tool == "claude" {
        std::fs::write(
            dir.join(".claude.json"),
            serde_json::to_vec(&serde_json::json!({
                "oauthAccount": {"accountUuid": account}
            }))
            .unwrap(),
        )
        .unwrap();
    } else {
        std::fs::write(
            dir.join("auth.json"),
            serde_json::to_vec(&serde_json::json!({
                "tokens": {"account_id": account}
            }))
            .unwrap(),
        )
        .unwrap();
    }
}

#[cfg(target_os = "linux")]
fn fake_refresh_curl(root: &std::path::Path, answer: &str) -> std::path::PathBuf {
    use std::os::unix::fs::PermissionsExt;
    let path = root.join("fake-refresh-curl");
    std::fs::write(
        &path,
        format!(
            "#!/bin/sh\ncat > /dev/null\nprintf x >> \"$SWAPDEX_TEST_REFRESH_COUNT\"\nprintf '{answer}\\n200'\n"
        ),
    )
    .unwrap();
    std::fs::set_permissions(&path, std::fs::Permissions::from_mode(0o755)).unwrap();
    path
}

#[cfg(target_os = "linux")]
fn refresh_calls(root: &std::path::Path) -> usize {
    std::fs::read(root.join("refresh-count"))
        .map(|b| b.len())
        .unwrap_or(0)
}

/// A process can hold the same provider account from a second config directory.
/// Refreshing either copy retires the token held by the other, so the active
/// twin must protect the candidate even though their paths differ. An unrelated
/// known account must not block it.
#[cfg(target_os = "linux")]
fn check_explicit_active_twin(tool: &str, candidate_account: &str, url_var: &str) {
    for (running_account, should_refresh) in [(candidate_account, false), ("someone-else", true)] {
        let root = tempfile::tempdir().unwrap();
        let candidate = if tool == "claude" {
            seed_lapsed_account(root.path(), "work", "candidate")
        } else {
            seed_lapsed_codex(root.path(), "work", "candidate")
        };
        let external = root.path().join(format!(".{tool}-external"));
        seed_external_identity(&external, tool, running_account);
        let _running = running_tool(root.path(), tool, &external);
        let answer = if tool == "claude" {
            r#"{"access_token":"NEW-AT","refresh_token":"NEW-RT","expires_in":3600}"#
        } else {
            r#"{"access_token":"NEW-AT","refresh_token":"NEW-RT","id_token":"NEW-ID"}"#
        };
        let curl = fake_refresh_curl(root.path(), answer);

        let out = Command::new(bin())
            .args(["refresh", "work"])
            .env("SWAPDEX_ROOT", root.path())
            .env("SWAPDEX_CURL", curl)
            .env(
                "SWAPDEX_TEST_REFRESH_COUNT",
                root.path().join("refresh-count"),
            )
            .env(url_var, "http://127.0.0.1:1/fake-oauth")
            .output()
            .unwrap();
        let said = String::from_utf8_lossy(&out.stdout).into_owned()
            + &String::from_utf8_lossy(&out.stderr);
        assert_eq!(
            refresh_calls(root.path()),
            usize::from(should_refresh),
            "{tool}: active account {running_account:?} gave the wrong refresh verdict:\n{said}"
        );
        assert_eq!(
            out.status.code(),
            Some(if should_refresh { 0 } else { 4 }),
            "{tool}: {said}"
        );
        if should_refresh {
            assert!(said.contains("work renewed"), "{tool}: {said}");
        } else {
            assert!(
                !said.contains("work renewed"),
                "{tool}: refreshed a twin held by a live process:\n{said}"
            );
            let unchanged = if tool == "claude" {
                credential(&candidate)["claudeAiOauth"]["accessToken"] == "OLD-AT"
            } else {
                codex_auth(&candidate)["tokens"]["access_token"] != "NEW-AT"
            };
            assert!(unchanged, "{tool}: the protected credential changed");
        }
    }
}

#[cfg(target_os = "linux")]
#[test]
fn explicit_refresh_protects_an_active_claude_twin_but_not_an_unrelated_account() {
    check_explicit_active_twin("claude", "u-work", "SWAPDEX_OAUTH_URL");
}

#[cfg(target_os = "linux")]
#[test]
fn explicit_refresh_protects_an_active_codex_twin_but_not_an_unrelated_account() {
    check_explicit_active_twin("codex", "acct-1", "SWAPDEX_CODEX_OAUTH_URL");
}

/// The unattended sweep reaches the same refresh entry point as an explicit
/// command. It must stand down for an active twin too, for both providers.
#[cfg(target_os = "linux")]
fn check_keep_alive_active_twin(tool: &str, account: &str, url_var: &str) {
    let root = tempfile::tempdir().unwrap();
    if tool == "claude" {
        seed_lapsed_account(root.path(), "idle", "candidate");
    } else {
        seed_lapsed_codex(root.path(), "idle", "candidate");
    }
    let external = root.path().join(format!(".{tool}-external"));
    seed_external_identity(&external, tool, account);
    let _running = running_tool(root.path(), tool, &external);
    let answer = if tool == "claude" {
        r#"{"access_token":"NEW-AT","refresh_token":"NEW-RT","expires_in":3600}"#
    } else {
        r#"{"access_token":"NEW-AT","refresh_token":"NEW-RT","id_token":"NEW-ID"}"#
    };
    let curl = fake_refresh_curl(root.path(), answer);

    let out = Command::new(bin())
        .args(["refresh", "--keep-alive"])
        .env("SWAPDEX_ROOT", root.path())
        .env("SWAPDEX_CURL", curl)
        .env(
            "SWAPDEX_TEST_REFRESH_COUNT",
            root.path().join("refresh-count"),
        )
        .env(url_var, "http://127.0.0.1:1/fake-oauth")
        .output()
        .unwrap();
    let said =
        String::from_utf8_lossy(&out.stdout).into_owned() + &String::from_utf8_lossy(&out.stderr);
    assert_eq!(
        refresh_calls(root.path()),
        0,
        "{tool}: keep-alive refreshed an account held through a twin:\n{said}"
    );
}

#[cfg(target_os = "linux")]
#[test]
fn keep_alive_sweep_protects_an_active_claude_twin() {
    check_keep_alive_active_twin("claude", "u-idle", "SWAPDEX_OAUTH_URL");
}

#[cfg(target_os = "linux")]
#[test]
fn keep_alive_sweep_protects_an_active_codex_twin() {
    check_keep_alive_active_twin("codex", "acct-1", "SWAPDEX_CODEX_OAUTH_URL");
}

#[test]
fn a_lapsed_codex_account_is_renewed_in_place() {
    let t = tempfile::tempdir().unwrap();
    let root = t.path();
    let slot = seed_lapsed_codex(root, "work", "codex-1");
    let asked = Arc::new(Mutex::new(Vec::new()));
    let url = fake_oauth(
        asked.clone(),
        r#"{"access_token":"NEW-AT","refresh_token":"NEW-RT","id_token":"NEW-ID"}"#,
    );

    let out = Command::new(bin())
        .args(["refresh", "work"])
        .env("SWAPDEX_ROOT", root)
        .env("SWAPDEX_CODEX_OAUTH_URL", &url)
        .output()
        .unwrap();
    let text = String::from_utf8_lossy(&out.stdout).into_owned();
    assert!(text.contains("work renewed"), "stdout was:\n{text}");

    // The request is the one the working implementation sends: form-encoded,
    // the account's own refresh token, Codex's public client id.
    let body = asked.lock().unwrap().first().cloned().unwrap_or_default();
    assert!(body.contains("grant_type=refresh_token"), "body: {body}");
    assert!(body.contains("refresh_token=OLD-RT"), "body: {body}");
    assert!(
        body.contains("client_id=app_EMoamEEZ73f0CkXaXp7hrann"),
        "body: {body}"
    );

    // And the answer landed in the file Codex reads, keeping its other fields.
    let a = codex_auth(&slot);
    assert_eq!(a["tokens"]["access_token"], "NEW-AT");
    assert_eq!(
        a["tokens"]["refresh_token"], "NEW-RT",
        "the ROTATED token must be written, or the slot holds one the server retired"
    );
    assert_eq!(a["tokens"]["id_token"], "NEW-ID");
    assert_eq!(
        a["tokens"]["account_id"], "acct-1",
        "untouched fields survive"
    );
    assert_eq!(a["auth_mode"], "chatgpt");
    assert_ne!(a["last_refresh"], "2026-08-19T07:41:56Z", "stamped anew");
}

#[test]
fn a_codex_renewal_the_server_refuses_changes_nothing() {
    let t = tempfile::tempdir().unwrap();
    let root = t.path();
    let slot = seed_lapsed_codex(root, "work", "codex-1");
    let before = codex_auth(&slot);
    let url = fake_oauth(
        Arc::new(Mutex::new(Vec::new())),
        r#"{"error":"invalid_grant"}"#,
    );
    // tiny_http answers 200 by default, so a refusal is modelled as a body with
    // no access token - the other half of the same guard.
    let out = Command::new(bin())
        .args(["refresh", "work"])
        .env("SWAPDEX_ROOT", root)
        .env("SWAPDEX_CODEX_OAUTH_URL", &url)
        .output()
        .unwrap();
    assert_eq!(out.status.code(), Some(4));
    assert_eq!(
        codex_auth(&slot),
        before,
        "an answer with no access token must leave the credential alone"
    );
}

/// An OAuth server that retires a refresh token when it is spent, the way the
/// real one does. The first request carrying OLD-RT is answered; every later
/// one is refused, because by then the server has retired it.
fn rotating_oauth(sink: Arc<Mutex<Vec<String>>>) -> String {
    let server = tiny_http::Server::http("127.0.0.1:0").unwrap();
    let port = server.server_addr().to_ip().unwrap().port();
    std::thread::spawn(move || {
        let mut spent = false;
        for mut rq in server.incoming_requests() {
            let mut body = String::new();
            std::io::Read::read_to_string(rq.as_reader(), &mut body).ok();
            let holds_retired = body.contains("OLD-RT");
            sink.lock().unwrap().push(body);
            let resp = if holds_retired && !spent {
                spent = true;
                tiny_http::Response::from_string(
                    r#"{"access_token":"NEW-AT","refresh_token":"NEW-RT","expires_in":3600}"#,
                )
                .with_status_code(200)
            } else {
                tiny_http::Response::from_string(r#"{"error":"invalid_grant"}"#)
                    .with_status_code(400)
            };
            let _ = rq.respond(resp);
        }
    });
    format!("http://127.0.0.1:{port}/v1/oauth/token")
}

/// Several lapsed Claude slots that all hold the SAME account - two directories
/// for one login, which `doctor` already reports as a thing people do.
fn seed_lapsed_twins(root: &std::path::Path, slots: &[(&str, &str, &str)]) {
    let store = root.join(".local/share/swapdex");
    let now_ms = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .unwrap()
        .as_millis() as i64;
    let mut reg = Vec::new();
    for (name, id, uuid) in slots {
        let slot = store.join("slots").join(id);
        std::fs::create_dir_all(&slot).unwrap();
        std::fs::write(
            slot.join(".credentials.json"),
            format!(
                r#"{{"claudeAiOauth":{{"accessToken":"OLD-AT","refreshToken":"OLD-RT",
                   "expiresAt":{},"refreshTokenExpiresAt":{},"subscriptionType":"max",
                   "scopes":["user:inference"]}}}}"#,
                now_ms - 3_600_000,
                now_ms + 30 * 86_400_000
            ),
        )
        .unwrap();
        std::fs::write(
            slot.join(".claude.json"),
            format!(
                r#"{{"oauthAccount":{{"accountUuid":"{uuid}","emailAddress":"shared@x.com"}}}}"#
            ),
        )
        .unwrap();
        reg.push(serde_json::json!({
            "name": name, "id": id, "config_dir": slot,
            "adopted": false, "tool": "claude-code"
        }));
    }
    std::fs::write(store.join("slots.json"), serde_json::to_vec(&reg).unwrap()).unwrap();
}

/// Two slots holding ONE account must be renewed once, not twice.
///
/// swapdex states the rule itself, in the remedy for a slot already being
/// renewed: "spending its refresh token twice is what logs an account out".
/// That guard is per DIRECTORY. Two directories holding one login are the same
/// double-spend and were not guarded, so `swapdex refresh` renewed the first,
/// the server retired the token both were holding, and the loop then spent the
/// retired one on behalf of the second - which the server refused, and the
/// second was reported as having been idle too long with a fresh sign-in as the
/// cure, seconds after its account had in fact been renewed.
#[test]
fn two_slots_on_one_account_are_renewed_once() {
    let root = tempfile::tempdir().unwrap();
    seed_lapsed_twins(
        root.path(),
        &[
            ("work", "aaaa1111", "u-shared"),
            ("work-copy", "bbbb2222", "u-shared"),
        ],
    );
    let asked = Arc::new(Mutex::new(Vec::new()));
    let url = rotating_oauth(asked.clone());

    let out = Command::new(bin())
        .args(["refresh"])
        .env("SWAPDEX_ROOT", root.path())
        .env("SWAPDEX_OAUTH_URL", &url)
        .env("HOME", root.path())
        .output()
        .unwrap();
    let said =
        String::from_utf8_lossy(&out.stdout).into_owned() + &String::from_utf8_lossy(&out.stderr);

    let bodies = asked.lock().unwrap().clone();
    let spends = bodies.iter().filter(|b| b.contains("OLD-RT")).count();
    assert_eq!(
        spends, 1,
        "the retired refresh token was spent {spends} times:\n{said}\nrequests: {bodies:?}"
    );
    assert!(
        !said.contains("idle too long"),
        "the twin was blamed for being idle when its account had just been renewed:\n{said}"
    );
}

/// Distinct accounts are each renewed; the guard is about one login, not two.
///
/// Skipping the second slot whenever anything was renewed would turn a fleet
/// refresh into a single refresh, which is the ordinary case this command
/// exists for. The check has to compare accounts, not count renewals.
#[test]
fn slots_on_different_accounts_are_each_renewed() {
    let root = tempfile::tempdir().unwrap();
    seed_lapsed_twins(
        root.path(),
        &[("one", "aaaa1111", "u-one"), ("two", "bbbb2222", "u-two")],
    );
    let asked = Arc::new(Mutex::new(Vec::new()));
    let url = fake_oauth(
        asked.clone(),
        r#"{"access_token":"NEW-AT","refresh_token":"NEW-RT","expires_in":3600}"#,
    );

    let out = Command::new(bin())
        .args(["refresh"])
        .env("SWAPDEX_ROOT", root.path())
        .env("SWAPDEX_OAUTH_URL", &url)
        .env("HOME", root.path())
        .output()
        .unwrap();
    let said =
        String::from_utf8_lossy(&out.stdout).into_owned() + &String::from_utf8_lossy(&out.stderr);

    assert!(
        said.contains("one renewed"),
        "'one' was not renewed:\n{said}"
    );
    assert!(
        said.contains("two renewed"),
        "'two' was not renewed:\n{said}"
    );
    assert_eq!(
        asked.lock().unwrap().len(),
        2,
        "two accounts, two renewals:\n{said}"
    );
}

/// The keep-alive sweep must renew an account once, however many directories
/// hold it.
///
/// The account guard was added to the `refresh` command's own loop, and this
/// sweep reaches `refresh_slot` by another road - the same mistake the gate's
/// note in refresh.rs records: "a rule enforced at one caller is a rule the
/// next caller does not know exists". Two slots on one login, and the sweep
/// spent the token the first renewal had already retired.
#[test]
fn the_keep_alive_sweep_renews_an_account_once() {
    let root = tempfile::tempdir().unwrap();
    seed_lapsed_twins(
        root.path(),
        &[
            ("work", "aaaa1111", "u-shared"),
            ("work-copy", "bbbb2222", "u-shared"),
        ],
    );
    // Due by the refresh token's end, which is what a sweep renews on.
    let now_ms = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .unwrap()
        .as_millis() as i64;
    for id in ["aaaa1111", "bbbb2222"] {
        let path = root
            .path()
            .join(".local/share/swapdex/slots")
            .join(id)
            .join(".credentials.json");
        let mut v: serde_json::Value =
            serde_json::from_slice(&std::fs::read(&path).unwrap()).unwrap();
        v["claudeAiOauth"]["refreshTokenExpiresAt"] = (now_ms + 2 * 86_400_000).into();
        std::fs::write(&path, serde_json::to_vec(&v).unwrap()).unwrap();
    }
    let asked = Arc::new(Mutex::new(Vec::new()));
    let url = rotating_oauth(asked.clone());

    let out = Command::new(bin())
        .args(["refresh", "--keep-alive"])
        .env("SWAPDEX_ROOT", root.path())
        .env("SWAPDEX_OAUTH_URL", &url)
        .env("HOME", root.path())
        .output()
        .unwrap();
    let said =
        String::from_utf8_lossy(&out.stdout).into_owned() + &String::from_utf8_lossy(&out.stderr);

    let bodies = asked.lock().unwrap().clone();
    let spends = bodies.iter().filter(|b| b.contains("OLD-RT")).count();
    assert_eq!(
        spends, 1,
        "the sweep spent the retired refresh token {spends} times:\n{said}\nrequests: {bodies:?}"
    );
}

/// Two slots whose identity cannot be read are not one account.
///
/// The claim key falls back to the path when a slot's login cannot be
/// identified. Collapsing unknowns onto one key instead would let the first
/// unreadable slot claim the renewal for every other unreadable slot, and a
/// fleet where identity files are missing would renew exactly one account.
#[test]
fn slots_with_unreadable_identity_are_each_renewed() {
    let root = tempfile::tempdir().unwrap();
    seed_lapsed_twins(
        root.path(),
        &[("one", "aaaa1111", "u-one"), ("two", "bbbb2222", "u-two")],
    );
    // Take the identity away from both: only the credential is left.
    for id in ["aaaa1111", "bbbb2222"] {
        std::fs::remove_file(
            root.path()
                .join(".local/share/swapdex/slots")
                .join(id)
                .join(".claude.json"),
        )
        .unwrap();
    }
    let asked = Arc::new(Mutex::new(Vec::new()));
    let url = fake_oauth(
        asked.clone(),
        r#"{"access_token":"NEW-AT","refresh_token":"NEW-RT","expires_in":3600}"#,
    );

    let out = Command::new(bin())
        .args(["refresh"])
        .env("SWAPDEX_ROOT", root.path())
        .env("SWAPDEX_OAUTH_URL", &url)
        .env("HOME", root.path())
        .output()
        .unwrap();
    let said =
        String::from_utf8_lossy(&out.stdout).into_owned() + &String::from_utf8_lossy(&out.stderr);
    assert_eq!(
        asked.lock().unwrap().len(),
        2,
        "two unidentifiable slots were treated as one account:\n{said}"
    );
}

/// `restore` must say when the login it is putting back was retired.
///
/// It applies a backup without either check `use` performs: no word that the
/// snapshot is old, and nothing about a refresh token some other holder has
/// since rotated away. These tokens are single-use, so a backup taken before a
/// renewal elsewhere is dead - and restoring it replaces a working login with
/// one that cannot renew, reported as a success. `restore` is the escape hatch,
/// so it still restores; it must not do it silently.
#[test]
fn restore_says_when_the_backup_it_puts_back_was_retired() {
    let root = tempfile::tempdir().unwrap();
    let store = root.path().join(".local/share/swapdex");
    std::fs::create_dir_all(store.join("slots/live")).unwrap();
    std::fs::write(store.join("onboarded"), b"1").unwrap();

    // A live slot holding the account, with the token the last rotation minted.
    let slot = store.join("slots/live");
    std::fs::write(
        slot.join(".credentials.json"),
        br#"{"claudeAiOauth":{"accessToken":"AT","refreshToken":"RT-NEW","expiresAt":9999999999999,"subscriptionType":"max"}}"#,
    )
    .unwrap();
    std::fs::write(
        slot.join(".claude.json"),
        br#"{"oauthAccount":{"accountUuid":"u-shared","emailAddress":"shared@example.com"}}"#,
    )
    .unwrap();
    std::fs::write(
        store.join("slots.json"),
        format!(
            r#"[{{"name":"live","id":"live","config_dir":"{}","adopted":false,"tool":"claude-code"}}]"#,
            slot.display()
        ),
    )
    .unwrap();

    // A backup of the SAME account carrying the token that rotation retired.
    let backup = store.join("backups/claude-code/1");
    std::fs::create_dir_all(&backup).unwrap();
    std::fs::write(
        backup.join("credentials"),
        br#"{"claudeAiOauth":{"accessToken":"AT-OLD","refreshToken":"RT-OLD"}}"#,
    )
    .unwrap();
    std::fs::write(
        backup.join("oauth_account"),
        br#"{"accountUuid":"u-shared","emailAddress":"shared@example.com"}"#,
    )
    .unwrap();

    let out = Command::new(bin())
        .args(["restore", "--tool", "claude"])
        .env("SWAPDEX_ROOT", root.path())
        .env("HOME", root.path())
        .output()
        .unwrap();
    let said =
        String::from_utf8_lossy(&out.stdout).into_owned() + &String::from_utf8_lossy(&out.stderr);
    assert!(
        said.contains("retired") || said.contains("rotated") || said.contains("renew"),
        "restore put back a retired login without a word:\n{said}"
    );
}

/// A refresh token the login server refused has settled the account: only a
/// sign-in helps. The sweep logged the refusal and tried again every pass, and
/// `ls`, reading only the access token, could not tell a refused account from
/// an idle one. The refusal is now recorded and shown, the sweep stops
/// retrying it, and asking by name still re-checks it.
#[test]
fn a_refused_claude_refresh_is_recorded_shown_and_not_swept_again() {
    let root = tempfile::tempdir().unwrap();
    let slot = seed_lapsed_account(root.path(), "gone", "cccc3333");
    let path = slot.join(".credentials.json");
    let mut v: serde_json::Value = serde_json::from_slice(&std::fs::read(&path).unwrap()).unwrap();
    let now_ms = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .unwrap()
        .as_millis() as i64;
    v["claudeAiOauth"]["refreshTokenExpiresAt"] = (now_ms + 86_400_000).into();
    std::fs::write(&path, serde_json::to_vec(&v).unwrap()).unwrap();

    let asked = Arc::new(Mutex::new(Vec::new()));
    let url = refusing_oauth(
        asked.clone(),
        400,
        r#"{"error":"invalid_grant","error_description":"Refresh token not found or invalid"}"#,
    );
    let swapdex = |args: &[&str]| {
        let out = Command::new(bin())
            .args(args)
            .env("SWAPDEX_ROOT", root.path())
            .env("SWAPDEX_OAUTH_URL", &url)
            .output()
            .unwrap();
        String::from_utf8_lossy(&out.stdout).into_owned() + &String::from_utf8_lossy(&out.stderr)
    };

    let said = swapdex(&["refresh", "--keep-alive"]);
    assert_eq!(asked.lock().unwrap().len(), 1, "{said}");
    let listing = swapdex(&["ls"]);
    assert!(
        listing.contains("claude-code refresh rejected (invalid_grant) - re-login required"),
        "the refusal and its reason are not shown:\n{listing}"
    );
    let said = swapdex(&["refresh", "--keep-alive"]);
    assert_eq!(
        asked.lock().unwrap().len(),
        1,
        "the sweep spent another request on a refused token: {said}"
    );
    let said = swapdex(&["refresh", "gone"]);
    assert_eq!(
        asked.lock().unwrap().len(),
        2,
        "asking by name did not re-check the refused token: {said}"
    );
}

/// The token endpoint answers a request it cannot parse with the same 400 it
/// gives a dead token; only `invalid_grant` is the verdict on the login.
/// Recording any 400 made the sweep stop renewing a login that was fine.
#[test]
fn a_claude_400_without_invalid_grant_is_not_recorded_as_a_refusal() {
    let root = tempfile::tempdir().unwrap();
    let slot = seed_lapsed_account(root.path(), "odd", "dddd4444");
    let path = slot.join(".credentials.json");
    let mut v: serde_json::Value = serde_json::from_slice(&std::fs::read(&path).unwrap()).unwrap();
    let now_ms = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .unwrap()
        .as_millis() as i64;
    v["claudeAiOauth"]["refreshTokenExpiresAt"] = (now_ms + 86_400_000).into();
    std::fs::write(&path, serde_json::to_vec(&v).unwrap()).unwrap();
    let asked = Arc::new(Mutex::new(Vec::new()));
    let url = refusing_oauth(
        asked.clone(),
        400,
        r#"{"error":"invalid_request","error_description":"malformed"}"#,
    );
    let sweep = || {
        let out = Command::new(bin())
            .args(["refresh", "--keep-alive"])
            .env("SWAPDEX_ROOT", root.path())
            .env("SWAPDEX_OAUTH_URL", &url)
            .output()
            .unwrap();
        String::from_utf8_lossy(&out.stdout).into_owned() + &String::from_utf8_lossy(&out.stderr)
    };
    sweep();
    assert!(
        !slot.join(".swapdex-claude-refresh-status.json").exists(),
        "a 400 without invalid_grant was recorded as a refusal"
    );
    let said = sweep();
    assert_eq!(
        asked.lock().unwrap().len(),
        2,
        "the sweep stopped renewing after a 400 that was no verdict: {said}"
    );
}

/// The login server answered with a new refresh token - and retired the old
/// one - but saving it failed. The new token was dropped, the old one was
/// already spent, and the account was signed out. The answer is now kept
/// outside the slot and adopted on the next renewal, without asking the
/// server again.
#[cfg(unix)]
#[test]
fn a_renewal_that_could_not_be_saved_is_kept_and_adopted_next_time() {
    use std::os::unix::fs::PermissionsExt;
    let root = tempfile::tempdir().unwrap();
    let slot = seed_lapsed_account(root.path(), "keep", "eeee5555");
    let asked = Arc::new(Mutex::new(Vec::new()));
    let server = tiny_http::Server::http("127.0.0.1:0").unwrap();
    let port = server.server_addr().to_ip().unwrap().port();
    let (sink, locked) = (asked.clone(), slot.clone());
    std::thread::spawn(move || {
        for mut rq in server.incoming_requests() {
            let mut seen = String::new();
            std::io::Read::read_to_string(rq.as_reader(), &mut seen).ok();
            sink.lock().unwrap().push(seen);
            // The server has rotated the token; now the save will fail.
            std::fs::set_permissions(&locked, std::fs::Permissions::from_mode(0o500)).unwrap();
            let _ = rq.respond(tiny_http::Response::from_string(
                r#"{"access_token":"NEW-AT","refresh_token":"NEW-RT","expires_in":28800}"#,
            ));
        }
    });
    let url = format!("http://127.0.0.1:{port}/v1/oauth/token");
    let refresh = || {
        let out = Command::new(bin())
            .args(["refresh", "keep"])
            .env("SWAPDEX_ROOT", root.path())
            .env("SWAPDEX_OAUTH_URL", &url)
            .output()
            .unwrap();
        String::from_utf8_lossy(&out.stdout).into_owned() + &String::from_utf8_lossy(&out.stderr)
    };

    let first = refresh();
    std::fs::set_permissions(&slot, std::fs::Permissions::from_mode(0o700)).unwrap();
    // The read-only slot that failed the save also kept the refresh lock from
    // being released; a real failed save (a locked keychain, a full disk)
    // releases it as usual.
    let _ = std::fs::remove_dir(slot.join(".oauth_refresh.lock"));
    assert_eq!(asked.lock().unwrap().len(), 1, "{first}");
    let saved = std::fs::read_to_string(slot.join(".credentials.json")).unwrap();
    assert!(
        saved.contains("OLD-RT"),
        "the failed save changed the file: {first}"
    );

    let second = refresh();
    let saved = std::fs::read_to_string(slot.join(".credentials.json")).unwrap();
    assert!(
        saved.contains("NEW-RT"),
        "the renewal the server already made was lost:\n{first}\n{second}"
    );
    assert_eq!(
        asked.lock().unwrap().len(),
        1,
        "the spent token was sent again instead of adopting the kept answer: {second}"
    );
}

/// The over-correction: a kept answer belongs to the token it renewed. After
/// a new sign-in it is obsolete and must not overwrite the new login.
#[cfg(unix)]
#[test]
fn a_kept_renewal_never_overwrites_a_newer_sign_in() {
    use std::os::unix::fs::PermissionsExt;
    let root = tempfile::tempdir().unwrap();
    let slot = seed_lapsed_account(root.path(), "relog", "ffff6666");
    let asked = Arc::new(Mutex::new(Vec::new()));
    let server = tiny_http::Server::http("127.0.0.1:0").unwrap();
    let port = server.server_addr().to_ip().unwrap().port();
    let (sink, locked) = (asked.clone(), slot.clone());
    std::thread::spawn(move || {
        for mut rq in server.incoming_requests() {
            let mut seen = String::new();
            std::io::Read::read_to_string(rq.as_reader(), &mut seen).ok();
            let first = {
                let mut sink = sink.lock().unwrap();
                sink.push(seen);
                sink.len() == 1
            };
            if first {
                std::fs::set_permissions(&locked, std::fs::Permissions::from_mode(0o500)).unwrap();
            }
            let body = if first {
                r#"{"access_token":"KEPT-AT","refresh_token":"KEPT-RT","expires_in":28800}"#
            } else {
                r#"{"access_token":"FRESH-AT","refresh_token":"FRESH-RT","expires_in":28800}"#
            };
            let _ = rq.respond(tiny_http::Response::from_string(body));
        }
    });
    let url = format!("http://127.0.0.1:{port}/v1/oauth/token");
    let refresh = || {
        let out = Command::new(bin())
            .args(["refresh", "relog"])
            .env("SWAPDEX_ROOT", root.path())
            .env("SWAPDEX_OAUTH_URL", &url)
            .output()
            .unwrap();
        String::from_utf8_lossy(&out.stdout).into_owned() + &String::from_utf8_lossy(&out.stderr)
    };
    refresh();
    std::fs::set_permissions(&slot, std::fs::Permissions::from_mode(0o700)).unwrap();
    let _ = std::fs::remove_dir(slot.join(".oauth_refresh.lock"));

    // A new sign-in replaces the spent token before the next renewal.
    let path = slot.join(".credentials.json");
    let relogged = std::fs::read_to_string(&path)
        .unwrap()
        .replace("OLD-RT", "SIGNED-IN-RT");
    std::fs::write(&path, relogged).unwrap();

    let second = refresh();
    let saved = std::fs::read_to_string(&path).unwrap();
    assert!(
        !saved.contains("KEPT-RT"),
        "an obsolete kept renewal overwrote a newer sign-in: {second}"
    );
    let asked = asked.lock().unwrap();
    assert!(
        asked.len() == 2 && asked[1].contains("SIGNED-IN-RT"),
        "the new sign-in was not renewed with its own token: {second}"
    );
}