batch-rename-files.js

const fs = require('fs');
const path = require('path');

const _ = require('lodash');
const fp = require('lodash/fp');
const anyAscii = require('any-ascii');

const BASE_PATH = '~/Downloads/';

function normalizeTitle(title) {
  return fp.flow(
    fp.split(' - '),
    fp.reverse,
    fp.map(part => _.startCase(_.toLower(part))),
    fp.join(' - ')
  )(anyAscii(title));
}

function normalizeInDir(...args) {
  const dirPath = path.resolve(BASE_PATH, ...args);

  try {
    const files = fs.readdirSync(dirPath).filter(fileName => !_.startsWith(fileName, '.'));

    files.forEach(fileName => {
      const extName = path.extname(fileName);
      const newName = normalizeTitle(path.basename(fileName, extName)) + extName;
      fs.renameSync(path.resolve(dirPath, fileName), path.resolve(dirPath, newName));
    });
  } catch (err) {
    console.log('Err:', err);
  }
}

function groupByAuthor(...args) {
  const dirPath = path.resolve(BASE_PATH, ...args);

  try {
    const files = fs.readdirSync(dirPath).filter(fileName => !_.startsWith(fileName, '.'));

    const groupedFiles = _.groupBy(files, fileName => {
      const author = fileName.split(' - ')[0];
      return author;
    });

    _.toPairs(groupedFiles)
      .filter(([_author, titles]) => titles.length >= 3)
      .forEach(([author, titles]) => {
        fs.mkdirSync(path.resolve(dirPath, author));
        titles.forEach(title => fs.renameSync(path.resolve(dirPath, title), path.resolve(dirPath, author, title)));
      });
  } catch (err) {
    console.log('Err:', err);
  }
}

module.exports = { normalizeInDir, groupByAuthor };

package.json

{
  "name": "converter",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "any-ascii": "^0.1.5",
    "lodash": "^4.17.19"
  },
  "devDependencies": {
    "eslint": "^7.4.0",
    "prettier": "^2.0.5"
  }
}