text: var gulp = require('gulp'),
  sass = require('gulp-sass'),
  autoprefixer = require('gulp-autoprefixer'),
  cssnano = require('gulp-cssnano'),
  jshint = require('gulp-jshint'),
  uglify = require('gulp-uglify'),
  imagemin = require('gulp-imagemin'),
  rename = require('gulp-rename'),
  concat = require('gulp-concat'),
  notify = require('gulp-notify'),
  cache = require('gulp-cache'),
  livereload = require('gulp-livereload'),
  del = require('del');
  include = require('gulp-include'),
  sourcemaps = require('gulp-sourcemaps'),
  babel = require('gulp-babel'),
  plumber = require('gulp-plumber'),
  gutil = require('gulp-util'),
  insert = require('gulp-insert'),
  fs = require('fs');
  
  var version_no = "4.5.0",
  
  version = "/* Tabulator v" + version_no + " (c) Oliver Folkerd */\n";
  
  var gulp_src = gulp.src;
  gulp.src = function() {
      return gulp_src.apply(gulp, arguments)
      .pipe(plumber(function(error) {
          // Output an error message
          gutil.log(gutil.colors.red('Error (' + error.plugin + '): ' + error.message));
          // emit the end event, to properly end the task
          this.emit('end');
          })
      );
  };
  
  //build css
  gulp.task('styles', function() {
      return gulp.src('src/scss/**/tabulator*.scss')
      .pipe(sourcemaps.init())
      .pipe(insert.prepend(version + "\n"))
      .pipe(sass({outputStyle: 'expanded'}).on('error', sass.logError))
      .pipe(autoprefixer('last 4 version'))
      .pipe(gulp.dest('dist/css'))
      .pipe(rename({suffix: '.min'}))
      .pipe(cssnano({zindex: false}))
      .pipe(insert.prepend(version))
      .pipe(sourcemaps.write('.'))
      .pipe(gulp.dest('dist/css'))
      .on('end', function(){ gutil.log('Styles task complete'); })
      });
  
  
  //build tabulator
  gulp.task('tabulator', function() {
      //return gulp.src('src/js/**/*.js')
      return gulp.src('src/js/core_modules.js')
      .pipe(insert.prepend(version + "\n"))
      //.pipe(sourcemaps.init())
      .pipe(include())
      //.pipe(jshint())
      // .pipe(jshint.reporter('default'))
      .pipe(babel({
          //presets:['es2015']
          compact: false,
          presets: [["env",{
              "targets": {
                "browsers": ["last 4 versions"]
              },
              loose: true,
              modules: false,
          }, ], {  }]
        }))
      .pipe(concat('tabulator.js'))
      .pipe(gulp.dest('dist/js'))
      .pipe(rename({suffix: '.min'}))
      .pipe(uglify())
      .pipe(insert.prepend(version))
      // .pipe(sourcemaps.write('.'))
      .pipe(gulp.dest('dist/js'))
      //.pipe(notify({ message: 'Scripts task complete' }));
      .on('end', function(){ gutil.log('Tabulator Complete'); })
      //.on("error", console.log)
      });
  
  
  //simplified core js
  gulp.task('core', function() {
      return gulp.src('src/js/core.js')
      .pipe(insert.prepend(version + "\n"))
      .pipe(include())
      .pipe(babel({
          presets: [["env", {
            "targets": {
              "browsers": ["last 4 versions"]
          },
          loose: true,
          modules: false,
          }]
          ]
          }))
      .pipe(concat('tabulator_core.js'))
      .pipe(gulp.dest('dist/js'))
      .pipe(rename({suffix: '.min'}))
      .pipe(uglify())
      .pipe(insert.prepend(version))
      .pipe(gulp.dest('dist/js'))
      .on('end', function(){ gutil.log('Core complete'); })
      });
  
  
  
  //make jquery wrapper
  gulp.task('modules', function(){
  
      var path = __dirname + "/src/js/modules/";
  
      var files = fs.readdirSync(path);
  
      var core = ["layout.js", "localize.js", "comms.js"];
  
      files.forEach(function(file, index){
  
          if(!core.includes(file)){
              return gulp.src('src/js/modules/' + file)
              .pipe(insert.prepend(version + "\n"))
              .pipe(include())
              .pipe(babel({
                  presets: [["env", {
                    "targets": {
                      "browsers": ["last 4 versions"]
                  },
                  loose: true,
                  modules: false,
                  }]
                  ]
                  }))
              .pipe(concat(file))
              .pipe(gulp.dest('dist/js/modules/'))
              .pipe(rename({suffix: '.min'}))
              .pipe(uglify())
              .pipe(insert.prepend(version))
              .pipe(gulp.dest('dist/js/modules/'))
          }
          });
  
      });
  
  //make jquery wrapper
  gulp.task('jquery', function(){
      return gulp.src('src/js/jquery_wrapper.js')
      .pipe(insert.prepend(version + "\n"))
      .pipe(include())
      .pipe(babel({
          presets: [["env", {
            "targets": {
              "browsers": ["last 4 versions"]
          },
          loose: true,
          modules: false,
          }]
          ]
          }))
      .pipe(concat('jquery_wrapper.js'))
      .pipe(gulp.dest('dist/js'))
      .pipe(rename({suffix: '.min'}))
      .pipe(uglify())
      .pipe(insert.prepend(version))
      .pipe(gulp.dest('dist/js'))
      .on('end', function(){ gutil.log('jQuery wrapper complete'); })
  
      });
  
  
  gulp.task('scripts', function() {
      gulp.start('tabulator');
      gulp.start('core');
      gulp.start('modules');
      gulp.start('jquery');
      });
  
  gulp.task('clean', function() {
      return del(['dist/css', 'dist/js']);
      });
  
  
  gulp.task('default', ['clean'], function() {
      gulp.start('styles', 'scripts');
      });
  
  
  gulp.task('watch', function() {
  
      // Watch .scss files
      gulp.watch('src/scss/**/*.scss', ['styles']);
  
      // Watch .js files
      gulp.watch('src/js/**/*.js', ['scripts']);
  
      });