use axum::{extract::State, response::IntoResponse};
use metrics_exporter_prometheus::{PrometheusBuilder, PrometheusHandle};

pub fn init() -> PrometheusHandle {
    PrometheusBuilder::new().install_recorder().expect("install prometheus recorder")
}

pub async fn render(State(handle): State<PrometheusHandle>) -> impl IntoResponse {
    handle.render()
}

/// A render handle that does NOT install the global recorder — the global is a
/// process-wide singleton, so tests (many `AppState`s per process) must not
/// call [`init`]. Metrics emitted via the macros are dropped under this handle,
/// which is fine for tests that only exercise routes.
#[cfg(test)]
pub fn test_handle() -> PrometheusHandle {
    PrometheusBuilder::new().build_recorder().handle()
}