/** Minimal in-process TTL cache (single node, no eviction pressure expected). */
export class TtlCache<V> {
  private store = new Map<string, { value: V; expires: number }>();
  constructor(private readonly ttlMs: number) {}

  get(key: string): V | undefined {
    const hit = this.store.get(key);
    if (!hit) return undefined;
    if (hit.expires < Date.now()) {
      this.store.delete(key);
      return undefined;
    }
    return hit.value;
  }

  set(key: string, value: V): V {
    this.store.set(key, { value, expires: Date.now() + this.ttlMs });
    return value;
  }

  async getOrLoad(key: string, load: () => Promise<V>): Promise<V> {
    const hit = this.get(key);
    if (hit !== undefined) return hit;
    return this.set(key, await load());
  }

  clear(): void {
    this.store.clear();
  }
}