export type PolicyEntry = {
  entity: string;
  reason: string;
  recommendation: string;
  stateKey: string;
};

/**
 * `m.ban` is the stable value; `org.matrix.mjolnir.ban` is the legacy
 * (pre-stabilization) recommendation still emitted by older bots.
 */
export const normalizeRecommendation = (rec: string): string =>
  rec === 'org.matrix.mjolnir.ban' ? 'm.ban' : rec;

export function recommendationLabel(rec: string): string {
  if (normalizeRecommendation(rec) === 'm.ban') return 'Ban';
  return rec;
}

/**
 * Merge stable and legacy rule lists, one entry per entity + recommendation.
 * [Gitea #321] Keyed on the normalised recommendation: a bot publishing both
 * `m.ban` and its `org.matrix.mjolnir.ban` twin showed the rule twice.
 */
export function dedupePolicyEntries(entries: PolicyEntry[]): PolicyEntry[] {
  const seen = new Set<string>();
  const result: PolicyEntry[] = [];
  entries.forEach((entry) => {
    const key = `${entry.entity} ${normalizeRecommendation(entry.recommendation)}`;
    if (seen.has(key)) return;
    seen.add(key);
    result.push(entry);
  });
  return result;
}