export function getBrowserCodeStream(appName: string, opts?: PrebootOptions): any {
  opts = normalize(opts);

  let bOpts = {
    entries: [__dirname + '/../browser/preboot_browser.js'],
    standalone: 'preboot',
    basedir: __dirname + '/../browser',
    browserField: false
  };
  let b = browserify(bOpts);

  // ignore any strategies that are not being used
  ignoreUnusedStrategies(b, bOpts, opts.listen, listenStrategies, './listen/listen_by_');
  ignoreUnusedStrategies(b, bOpts, opts.replay, replayStrategies, './replay/replay_after_');

  if (opts.freeze) {
    ignoreUnusedStrategies(b, bOpts, [opts.freeze], freezeStrategies, './freeze/freeze_with_');
  }

  // ignore other code not being used
  if (!opts.buffer) { b.ignore('./buffer_manager.js', bOpts); }
  if (!opts.debug) { b.ignore('./log.js', bOpts); }

  // use gulp to get the stream with the custom preboot browser code
  let outputStream = b.bundle()
    .pipe(source('src/browser/preboot_browser.js'))
    .pipe(buffer())
    .pipe(insert.append('\n\n;preboot.init("' + appName + '",' + stringifyWithFunctions(opts) + ');\n\n'))
    .pipe(insert.append('\n\n;preboot.init("' + appName + '2",' + stringifyWithFunctions(opts) + ');\n\n'))
    .pipe(rename('preboot.js'));

  // uglify if the option is passed in
  return opts.uglify ? outputStream.pipe(uglify()) : outputStream;
}

 return (next: (arg?: any) => void) => {
   if (argv.verbose) gutil.log(`Building ${plugin_name}`)
   const pluginOpts = {
     entries: [path.resolve(path.join(paths.buildDir.jsTree, main))],
     extensions: [".js"],
     debug: true,
     preludePath: pluginPreludePath,
     prelude: pluginPreludeText,
     paths: ['./node_modules', paths.buildDir.jsTree],
   }
   const plugin = browserify(pluginOpts)
   labels[plugin_name] = namedLabeler(plugin, labels.bokehjs)
   for (const file in labels.bokehjs) {
     const name = labels.bokehjs[file]
     if (name !== "_process")
       plugin.external(file)
   }
   plugin
     .bundle()
     .pipe(source((paths.coffee as any)[plugin_name].destination.full))
     .pipe(buffer())
     .pipe(sourcemaps.init({loadMaps: true}))
     // This solves a conflict when requirejs is loaded on the page. Backbone
     // looks for `define` before looking for `module.exports`, which eats up
     // our backbone.
     .pipe(change((content: string) => {
       return `(function() { var define = undefined; return ${content} })()`
     }))
     .pipe(insert.append(license))
     .pipe(sourcemaps.write('./'))
     .pipe(gulp.dest(paths.buildDir.js))
     .on('end', () => next())
 }

 const tasks = [paths.coffee.bokehjs, paths.coffee.api, paths.coffee.widgets, paths.coffee.gl].map((entry) => {
   return gulp.src(entry.destination.fullWithPath)
     .pipe(rename((path) => path.basename += '.min'))
     .pipe(uglify({ output: {comments: /^!|copyright|license|\(c\)/i} }))
     .pipe(insert.append(license))
     .pipe(sourcemaps.write('./'))
     .pipe(gulp.dest(paths.buildDir.js))
 })

gulp.task("scripts:minify", ["scripts:bundle"], () => {
  return gulp.src(`${paths.build_dir.js}/!(*.min|compiler).js`)
    .pipe(sourcemaps.init({loadMaps: true}))
    .pipe(rename((path) => path.basename += '.min'))
    .pipe(minify({ output: { comments: /^!|copyright|license|\(c\)/i } }))
    .pipe(insert.append(license))
    .pipe(sourcemaps.write("."))
    .pipe(gulp.dest(paths.build_dir.js))
})

 function buildBokehjs(next: (arg?: any) => void) {
   if (argv.verbose) gutil.log("Building bokehjs")
   bokehjs.exclude(path.resolve("build/js/tree/models/glyphs/webgl/index.js"))
   labels.bokehjs = namedLabeler(bokehjs, {})
   bokehjs
     .bundle()
     .pipe(source(paths.coffee.bokehjs.destination.full))
     .pipe(buffer())
     .pipe(sourcemaps.init({loadMaps: true}))
     // This solves a conflict when requirejs is loaded on the page. Backbone
     // looks for `define` before looking for `module.exports`, which eats up
     // our backbone.
     .pipe(change((content: string) => {
       return `(function() { var define = undefined; return ${content} })()`
     }))
     .pipe(change((content: string) => {
       return `window.Bokeh = Bokeh = ${content}`
     }))
     .pipe(insert.append(license))
     .pipe(sourcemaps.write('./'))
     .pipe(gulp.dest(paths.buildDir.js))
     .on('end', () => next())
 }