gulpfile.js

'use strict';

const fs = require('fs');
const gulp = require('gulp');
const {server} = require('electron-connect')
const useref = require('gulp-useref');
const clean = require('gulp-clean');
const run = require('run-sequence');
const less = require('gulp-less');
const concat = require('gulp-concat');
const path = require('path');
const merge = require('merge-stream');

const PROD = process.env.NODE_ENV === 'production'
const OUT = "./app";
const CLEAN = [`!${OUT}/package.json`, `!${OUT}/node_modules`, `${OUT}/*`];
const semantic = './bower_components/semantic/src'

gulp.task('serve', function () {
    let electron = server.create({
      path: 'app'
    });

    // Start browser process
    electron.start('--debug');

    // Restart browser process
    gulp.watch('src/app.js', () => run('build:app', electron.restart))
    gulp.watch('src/lib/*.js', () => run('build:lib', electron.restart))

    // Reload renderer process
    gulp.watch(['src/*.html', 'src/scripts/**'], () => run('build:useref', electron.reload));
    gulp.watch(['src/views/**/*'], () => run('build:views', electron.reload));
    gulp.watch(['src/css/**/*'], () => run('build:less', electron.reload));
});

gulp.task('default', ['serve']);

gulp.task('clean', function() {
    return gulp.src(CLEAN, {read: false})
    .pipe(clean());
});

gulp.task('build:useref', function() {
    return gulp.src('src/*.html')
    .pipe(useref({
      dev: function(content) {
        return PROD ? '' : content
      }
    }))
    .pipe(gulp.dest(OUT))
});

gulp.task('build:app', function() {
  return gulp.src('src/app.js')
    .pipe(gulp.dest(OUT));
});

gulp.task('build:views', function() {
  return gulp.src('src/views/**/*', {base: 'src'})
    .pipe(gulp.dest(OUT))
})

gulp.task('build:lib', function() {
  return gulp.src('src/lib/**/*', {base: 'src'})
    .pipe(gulp.dest(OUT))
})

gulp.task('build:others', function() {
  return gulp.src(['src/css/fonts/**/*', 'src/img/**/*', 'build/**/*'], {base: 'src'})
    .pipe(gulp.dest(OUT))
})

gulp.task('build:assets' , function () {
    return gulp.src('./bower_components/semantic/dist/themes/default/assets/**')
    .pipe(gulp.dest(OUT + '/css/themes/default/assets'))
});

gulp.task('semantic:src', function() {
  return gulp.src([
    path.join(semantic, '**'),
    '!'+path.join(semantic, 'themes/**'),
    '!'+path.join(semantic, 'themes/')
  ]).pipe(gulp.dest('src/css/semantic'))
})

gulp.task('semantic:default', function() {
  let themes = ['default']
  return gulp.src(themes.map(t => path.join(semantic, 'themes', t, '/**')),
   {base: path.join(semantic, 'themes')})
    .pipe(gulp.dest('src/css/themes'))
})

gulp.task('build:semantic', ['semantic:src', 'semantic:default'])

gulp.task('build:static', ['build:app', 'build:views', 'build:lib', 'build:others', 'build:assets'])

gulp.task('build:less', function() {
  let dir = 'src/css/themes'
  let themes = fs.readdirSync(dir)
    .filter(function(file) {
      let stat = fs.statSync(path.join(dir, file))
      return stat.isDirectory() && file !== 'default'
    })

  let tasks = themes.map(function(theme) {
    return gulp.src(['src/css/semantic/semantic.less', 'src/css/styles.less'])
      .pipe(less({
        paths: [semantic],
        globalVars: {
          "@renderTheme": theme
        }
      }))
      .pipe(concat(theme + '.css'))
      .pipe(gulp.dest(path.join(OUT, 'css', 'themes')))
  })

  return merge(tasks)
})

gulp.task('build:styles', ['build:semantic'], function() {
  gulp.start('build:less')
})

gulp.task('build', ['build:useref', 'build:static', 'build:styles']);

gulp.task('install', ['build:semantic'])