import gulp         from 'gulp';
import gulpif       from 'gulp-if';
import source       from 'vinyl-source-stream';
import sourcemaps   from 'gulp-sourcemaps';
import buffer       from 'vinyl-buffer';
import streamify    from 'gulp-streamify';
import watchify     from 'watchify';
import browserify   from 'browserify';
import babelify     from 'babelify';
import uglify       from 'gulp-uglify';
import browserSync  from 'browser-sync';
import handleErrors from '../util/handleErrors';
import livereload   from 'gulp-livereload';
// import config       from '../config';

// Based on: http://blog.avisi.nl/2014/04/25/how-to-keep-a-fast-build-with-browserify-and-reactjs/
function buildScript(file) {

  const shouldCreateSourcemap = true;

  let bundler = browserify({
    entries: ['./app/' + file],
    debug: shouldCreateSourcemap,
    cache: {},
    packageCache: {},
    fullPaths: !global.isProd
  });

  if ( !global.isProd ) {
    bundler = watchify(bundler);

    bundler.on('update', rebundle);
  }

  const transforms = [
    { name: babelify, options: {} },
  ];

  transforms.forEach(function(transform) {
    bundler.transform(transform.name, transform.options);
  });

  function rebundle() {
    bundleLogger.start();

    const stream = bundler.bundle();
    const sourceMapLocation = global.isProd ? './' : '';

    return stream
      .on('error', handleErrors)
      .on('end', bundleLogger.end)
      .pipe(source(file))
      .pipe(gulpif(shouldCreateSourcemap, buffer()))
      .pipe(gulpif(shouldCreateSourcemap, sourcemaps.init({ loadMaps: true })))
      .pipe(gulpif(!shouldCreateSourcemap, streamify(uglify({
        compress: { drop_console: true } // eslint-disable-line camelcase
      }))))
      .pipe(gulpif(shouldCreateSourcemap, sourcemaps.write(sourceMapLocation)))
      .pipe(gulp.dest('./js'))
      .pipe(livereload());
  }

  return rebundle();

}

gulp.task('browserify', function() {

  return buildScript('main.js');

});