'use strict';
const gulp = require('gulp');
const browserify = require('browserify');
const rename = require('gulp-rename');
const babelify = require( 'babelify');
const buffer = require('vinyl-buffer');
const sourcemaps = require('gulp-sourcemaps');
const source = require('vinyl-source-stream');
const uglify = require('gulp-uglify-es').default;

function bundle_js(bundler) {
  return bundler.bundle()
  // .on('error', map_error)
    .pipe(source('app.js'))
    .pipe(buffer())
    .pipe(rename('bundle.js'))
    .pipe(sourcemaps.init({ 'loadMaps': true }))
  // capture sourcemaps from transforms
    .pipe(uglify())
    .pipe(sourcemaps.write('.'))
    .pipe(gulp.dest('./src/react'));
}

gulp.task('bundleReact', function () {
  const bundler = browserify('./src/react/js/app.js', { 'debug': true }).transform(babelify, { 'presets': ['es2015', 'react'] });

  return bundle_js(bundler);
});

gulp.task('buildReact', ['bundleReact'], function() {
  gulp.watch('src/react/js/**/*.js', ['bundleReact']);
});