import { readdir } from "node:fs/promises";
import { extname, join } from "node:path";

export async function getFilesWithExtensions(
  directory: string,
  extensions: string[],
  filter?: ((path: string) => boolean) | undefined
) {
  const files: string[] = [];

  const entries = await readdir(directory, { withFileTypes: true });

  for (const entry of entries) {
    const fullPath = join(directory, entry.name);

    if (entry.isDirectory()) {
      files.push(
        ...(await getFilesWithExtensions(fullPath, extensions, filter))
      );
    } else if (entry.isFile()) {
      const fileExtension = extname(entry.name);
      if (extensions.includes(fileExtension)) {
        if (typeof filter !== "function" || filter(fullPath)) {
          files.push(fullPath);
        }
      }
    }
  }

  return files;
}