utils = require '../../lib/utils'
    notify = require '../../lib/notify'
    log = require '../../lib/log'

    sources = require './sources'
    notifications = require './notifications'

    build = (cb) -> 

      css = []

First, add the CSS we chose _not_ to remove from the vendor mappings in `bower.json`. Since CSS isn't compiled here, no need to separate this.

      Array::push.apply css, sources.vendor.compile.css().map (dependency) -> dependency.file

List the local CSS files (it's assumed we're using all of these).

      utils.listFiles "#{process.cwd()}/css", '.css', (appCSS) -> 

        Array::push.apply css, appCSS

If we do not have any CSS (the default skeleton, for example) no need to concat/minify.

        return cb()  if css.length is 0

        switch process.env.NODE_ENV

In `development`, we just concat all CSS into a single file.

          when 'development'

            utils.concatFiles css, "#{process.cwd()}/_app/compiled/app.css", (error) ->

              notifications.compiler error  if error

              global.pages.assets.css.push 'compiled/app.css'

              cb()

In `production`, we additionally minify the single file.

          when 'production'

            utils.concatFiles css, "#{process.cwd()}/_app/compiled/app.css", (error) ->

               notifications.compiler error  if error

              utils.concatMinifyFile 'css', "#{process.cwd()}/_app/compiled/app.css", "#{process.cwd()}/_app/compiled/app.min.css", (error) ->

                notifications.compiler error  if error

                global.pages.assets.css.push 'compiled/app.min.css'

                cb()

## Public API ##

    publicFns = 
      build: build

    module.exports = publicFns