export type IncidentSeverity = "maintenance" | "degraded" | "outage";

export type ServiceStatusLevel =
  | "operational"
  | "maintenance"
  | "degraded"
  | "outage";

const severityRank: Record<IncidentSeverity, number> = {
  maintenance: 1,
  degraded: 2,
  outage: 3,
};

export function deriveServiceStatus(
  incidents: ReadonlyArray<{ severity: IncidentSeverity; status: string }>,
): ServiceStatusLevel {
  let selected: IncidentSeverity | null = null;
  for (const incident of incidents) {
    if (incident.status !== "active") continue;
    if (!selected || severityRank[incident.severity] > severityRank[selected]) {
      selected = incident.severity;
    }
  }
  return selected ?? "operational";
}