export const getHttpHeaderString = (value: unknown): string | undefined => {
  if (typeof value === "string") return value;
  if (Array.isArray(value) && value.every((item) => typeof item === "string")) {
    return value.join(", ");
  }
  return undefined;
};

export const getContentDispositionFilename = (header?: string | null): string | null => {
  if (!header) return null;
  const encoded = /filename\*\s*=\s*UTF-8''([^;]+)/i.exec(header)?.[1];
  if (encoded) {
    try {
      return decodeURIComponent(encoded.trim().replace(/^"|"$/g, ""));
    } catch {
      // Fall through to the ASCII filename when the RFC 5987 value is malformed.
    }
  }
  return /filename\s*=\s*"([^"]+)"|filename\s*=\s*([^;]+)/i.exec(header)?.slice(1).find(Boolean)?.trim() || null;
};