const { task, series, parallel, src, dest, watch } = require('gulp');
const babel = require('gulp-babel');
const uglify = require('gulp-uglify');
const concat = require('gulp-concat');
const clean = require('gulp-clean');
const livereload = require('gulp-livereload');

const cleanTask = function () {
  return src('dist/*', { read: false }).pipe(clean());
};

const script = function () {
  return src('src/**/*.js')
    .pipe(babel({ presets: ['@babel/env'] }))
    .pipe(uglify())
    .pipe(concat('main.js'))
    .pipe(dest('dist/'))
    .pipe(livereload({ start: true, port: 3001, reloadPage: 'public/index.html' }));
};

const watchTask = function () {
  livereload.listen();
  watch('src/*', series(cleanTask, script));
};

exports.default = parallel(script, watchTask);