export function knownMetric(value: number | null | undefined): number | "unavailable" {
  return typeof value === "number" && Number.isFinite(value) ? value : "unavailable";
}

export function knownQueueDepthTotal(depths: Record<string, number | null | undefined>): number | null {
  const values = Object.values(depths).filter((value): value is number => typeof value === "number" && Number.isFinite(value));
  return values.length ? values.reduce((total, value) => total + value, 0) : null;
}

export function runtimeWorkTone(state: string): "good" | "info" | "warning" | "danger" | "neutral" {
  if (state === "healthy" || state === "idle") return "good";
  if (state === "busy") return "info";
  if (state === "starting" || state === "degraded" || state === "unconfigured") return "warning";
  if (state === "stale" || state === "unreachable") return "danger";
  return "neutral";
}

export function heartbeatAgeSeconds(now: number, value?: string | null): number | null {
  if (!value) return null;
  const timestamp = Date.parse(value);
  if (!Number.isFinite(timestamp)) return null;
  return Math.max(0, Math.floor((now - timestamp) / 1000));
}

export function heartbeatAgeLabel(ageSeconds: number | null): string {
  if (ageSeconds === null) return "unavailable";
  if (ageSeconds < 60) return `${ageSeconds}s ago`;
  if (ageSeconds < 3600) return `${Math.floor(ageSeconds / 60)}m ago`;
  return `${Math.floor(ageSeconds / 3600)}h ago`;
}

export function shouldPollRuntimeStatus(hidden: boolean, requestInFlight: boolean): boolean {
  return !hidden && !requestInFlight;
}