export function sanitize(name: string): string {
  return name.replace(/[/\\:*?"<>|]/g, '_').trim();
}

export function sanitizePathSegment(name: unknown, fallback: string): string {
  const value = sanitize(String(name || '')).replace(/[. ]+$/g, '');
  return value && value !== '.' && value !== '..' ? value : fallback;
}

// "A/B" "A /B" -> "A / B"
export function formatPersonNames(value: string): string;
export function formatPersonNames(value: string | undefined): string | undefined;
export function formatPersonNames(value: string | undefined): string | undefined {
  return typeof value === 'string' ? value.replace(/\s*\/\s*/g, ' / ') : value;
}

export function joinNames(names: Array<{ name?: string } | string | undefined> | undefined): string {
  return (names || [])
    .map((item) => (typeof item === 'string' ? item : item?.name))
    .filter(Boolean)
    .join(' / ');
}

export function sleep(ms: number, signal?: AbortSignal): Promise<void> {
  return new Promise((resolve, reject) => {
    if (signal?.aborted) return reject(signal.reason);
    const timer = setTimeout(() => {
      signal?.removeEventListener('abort', onAbort);
      resolve();
    }, ms);
    const onAbort = () => {
      clearTimeout(timer);
      reject(signal!.reason);
    };
    signal?.addEventListener('abort', onAbort, { once: true });
  });
}

export function errorMessage(e: unknown): string {
  return e instanceof Error ? e.message : String(e);
}

// 简单的带过期时间的内存缓存，用于专辑详情等批量下载时反复请求的数据
export class TtlCache<V> {
  private map = new Map<string, { value: V; expires: number }>();
  private readonly ttlMs: number;
  private readonly max: number;

  constructor(ttlMs: number, max = 500) {
    this.ttlMs = ttlMs;
    this.max = max;
  }

  async getOrSet(key: string, load: () => Promise<V>): Promise<V> {
    const hit = this.map.get(key);
    if (hit && hit.expires > Date.now()) return hit.value;
    const value = await load();
    if (this.map.size >= this.max) this.map.delete(this.map.keys().next().value!);
    this.map.set(key, { value, expires: Date.now() + this.ttlMs });
    return value;
  }
}