import path from "path";
import { getAsyncImport } from "./getAsyncImport.ts";

/**
 * Возвращает массив всех файлов из папки при помощи модуля `fs`
 * @param dir{String} путь к папке
 * @param getFilterFn{Function=} функция фильтрации по файлам
 * @returns {Promise<string[]>}
 * @example
 * import { getFilesWithFS } from "@delement/ui/utils/node";
 *
 * const tsFiles = await getFilesWithFS("./src", (file) => file.endsWith(".ts"));
 */
const getFilesWithFS = async (
  dir: string = "",
  getFilterFn: ((file: string) => boolean) = (_file: string) => true
): Promise<string[]> => {
  if (!dir) {
    throw new Error("[getFilesWithFS] Вirectory not found");
  }

  const fs = await getAsyncImport("fs/promises") as typeof import("fs/promises");

  async function* getFileFromDir(currentDir: string): AsyncGenerator<string> {
    const dirs = await fs.readdir(currentDir, { withFileTypes: true });
    for (const dirent of dirs) {
      const resolvedPath = path.resolve(currentDir, dirent.name);
      if (dirent.isDirectory()) {
        yield* getFileFromDir(resolvedPath);
      } else {
        yield resolvedPath;
      }
    }
  }

  const files: string[] = [];
  for await (const file of getFileFromDir(dir)) {
    if (getFilterFn(file)) {
      files.push(file);
    }
  }

  return files;
};

export { getFilesWithFS };