did-hosting-server 0.9.0

use axum::Json;
use axum::http::StatusCode;
use serde::Serialize;

use crate::server::AppState;

#[derive(Serialize)]
pub struct HealthResponse {
    status: &'static str,
    version: &'static str,
}

/// Unauthenticated liveness probe; degraded while the service's own DID is
/// not being served.
#[cfg_attr(feature = "openapi", utoipa::path(
    get,
    path = "/api/health",
    tag = "system",
    responses(
        (status = 200, description = "Service is up and its own DID (if configured) resolves locally; returns status + version", content_type = "application/json"),
        (status = 503, description = "Service is up but its own DID isn't being served locally, or it has not reconciled with its control plane within the staleness bound", content_type = "application/json"),
    ),
))]
// Deliberately generic — no configuration or DID detail — but it must not
// claim healthy while the service's own DID isn't being served locally
// (Keyring VTI-17): see
// `did_hosting_common::server::health::own_did_served_locally`.
//
// Takes `AppState` directly rather than axum's `State` extractor: the
// route is registered *after* `Router::with_state` (deliberately outside
// the CORS/security-header layers — see `run_rest_thread`), so by the time
// it's added the router's state type is already `()` and an extractor-based
// handler would no longer type-check. The caller closes over a cloned
// `AppState` instead.
//
// It also answers 503 once the edge has gone longer than
// `replication.staleness_bound_secs` without a clean reconcile against its
// control plane (`crate::replication`), so a load balancer drains an edge that
// may be serving out-of-date state. The body stays generic either way.
pub async fn health(state: AppState) -> (StatusCode, Json<HealthResponse>) {
    let ok = did_hosting_common::server::health::own_did_served_locally(
        &state.dids_ks,
        state.config.server_did.as_deref(),
    )
    .await
        && crate::replication::is_fresh(&state);

    let status = if ok {
        StatusCode::OK
    } else {
        StatusCode::SERVICE_UNAVAILABLE
    };
    (
        status,
        Json(HealthResponse {
            status: if ok { "ok" } else { "degraded" },
            version: env!("CARGO_PKG_VERSION"),
        }),
    )
}