// What the alerts page lists, apart from how it draws it: the shape of one
// instance from swarm-controller's `GET /api/alerts` and which of them count
// as firing.

export interface Alert {
  name: string;
  // Grafana's state for the instance: `Alerting`, `Pending`, `NoData` or
  // `Error`.
  state: string;
  active_at: string | null;
  summary: string | null;
  labels: Record<string, string>;
}

const FIRING = "Alerting";

// The instances the page shows: the ones Grafana says are firing now. Pending,
// no-data and errored ones are left to Grafana's own list.
export function firingAlerts(alerts: Alert[]): Alert[] {
  return alerts.filter((a) => a.state === FIRING);
}

// What the page lists: the firing ones, or every instance once the operator
// asks for the rest.
export function listedAlerts(alerts: Alert[], showAll: boolean): Alert[] {
  return showAll ? alerts : firingAlerts(alerts);
}

// Grafana reports an instance that never became active with the zero time,
// which `Date.parse` reads as year 1.
export function activeSinceMs(a: Alert): number | null {
  if (a.active_at === null) return null;
  const ms = Date.parse(a.active_at);
  return Number.isNaN(ms) || ms <= 0 ? null : ms;
}

// A row needs a key that is unique among instances of the same rule.
export function alertKey(a: Alert): string {
  return JSON.stringify(Object.entries(a.labels).sort());
}