export const TRAFFIC_RETENTION_OPTIONS = [5, 10, 30] as const;

export type TrafficGrouping = 'site' | 'device';
export type TrafficSort = 'popular' | 'recent';
export type TrafficRetentionSeconds = typeof TRAFFIC_RETENTION_OPTIONS[number];

export interface TrafficSettings {
  grouping: TrafficGrouping;
  sort: TrafficSort;
  retentionSeconds: TrafficRetentionSeconds;
}

export const DEFAULT_TRAFFIC_SETTINGS: TrafficSettings = {
  grouping: 'site',
  sort: 'popular',
  retentionSeconds: 10,
};

export function normalizeTrafficSettings(
  value: unknown,
  { strict = false }: { strict?: boolean } = {},
): TrafficSettings {
  const candidate = value && typeof value === 'object' && !Array.isArray(value)
    ? value as Record<string, unknown>
    : {};
  const grouping = candidate.grouping;
  const sort = candidate.sort;
  const retentionSeconds = candidate.retentionSeconds;
  if (strict && (
    !['site', 'device'].includes(String(grouping))
    || !['popular', 'recent'].includes(String(sort))
    || !TRAFFIC_RETENTION_OPTIONS.includes(Number(retentionSeconds) as TrafficRetentionSeconds)
  )) throw new TypeError('Invalid traffic settings');
  return {
    grouping: grouping === 'device' ? 'device' : 'site',
    sort: sort === 'recent' ? 'recent' : 'popular',
    retentionSeconds: TRAFFIC_RETENTION_OPTIONS.includes(Number(retentionSeconds) as TrafficRetentionSeconds)
      ? Number(retentionSeconds) as TrafficRetentionSeconds
      : DEFAULT_TRAFFIC_SETTINGS.retentionSeconds,
  };
}