import { isString } from '@redneckz/json-op';
import { isLocalFileURL, isURL } from '../utils/url';

export const isAttachment =
  (exts: string[] = []) =>
  (src: unknown) =>
    isLocalPath(src) && (exts.length ? exts.some(ext => src.toLowerCase().endsWith(ext)) : hasSomeExt(src));

const isLocalPath = (_: unknown): _ is string =>
  Boolean(_ && isString(_) && _.length < 1024 && (!isURL(_) || isLocalFileURL(_)));

const hasSomeExt = (src: string): boolean => {
  const extIdx = src.lastIndexOf('.');
  const extLen = src.length - extIdx - 1;
  return extIdx !== -1 && extLen >= 2 && extLen <= 4;
};