assets.rake

task 'assets:precompile:before' do
  require 'uglifier'
  require 'sprockets'
  require 'term/ansicolor'
  include Term::ANSIColor

  unless %w{production}.include? Rails.env
    print yellow(bold("rake assets:precompile should only be run in RAILS_ENV=production, you are risking unminified assets")), "\n"
  end

  # Ensure we ALWAYS do a clean build
  # .erbs can get out of date quickly, especially with plugins
  print bold("--- Purging temp files"), "\n"
  `rm -fr #{Rails.root}/tmp/cache`

  print bold("--- Bundling assets"), "\n"
end

def assets_path
  "#{Rails.root}/public/assets"
end

def compress(from,to)
  data = File.read("#{assets_path}/#{from}")

  uglified, map = Uglifier.new(comments: :none,
                               screw_ie8: true,
                               source_filename: File.basename(from),
                               output_filename: File.basename(to)
                              )
                          .compile_with_map(data)

  dest = "#{assets_path}/#{to}"

  print bold("DEBUG -- : Writing Source Map for #{to}"), "\n"
  File.write(dest, uglified << "\n//# sourceMappingURL=#{"/assets/#{to}.map"}")
  print bold("DEBUG -- : Source Map for #{to} #{dest + ".map"}"), "\n"
  File.write(dest + ".map", map)
end

def gzip(path)
  print "gzip #{path}", "\n"
  print `gzip -f -c -7 #{path} > #{path}.gz`, "\n"
end

def concurrent?
  if ENV["CONCURRENT"] == "1"
    concurrent_compressors = []
    yield(Proc.new { |&block| concurrent_compressors << Concurrent::Future.execute { block.call } })
    concurrent_compressors.each(&:wait!)
  else
    yield(Proc.new { |&block| block.call })
  end
end

task 'assets:precompile' => 'assets:precompile:before' do
  manifest = Sprockets::Manifest.new(assets_path)

  concurrent? do |proc|
    manifest.files
            .select{|k,v| k =~ /\.js$/}
            .each do |file, info|

      path = "#{assets_path}/#{file}"
      _file = (d = File.dirname(file)) == "." ? "_#{file}" : "#{d}/_#{File.basename(file)}"
      _path = "#{assets_path}/#{_file}"

      if File.exists?(_path)
        print yellow(bold("Skipping: #{file} already compressed")), "\n"
      else
        print yellow(bold("Compressing: #{file}")), "\n"

        proc.call do
          # We can specify some files to never minify
          unless (ENV["DONT_MINIFY"] == "1")
            FileUtils.mv(path, _path)
            compress_ruby(_file,file)
          end

          info["size"] = File.size(path)
          info["mtime"] = File.mtime(path).iso8601
          gzip(path)
        end
      end
    end
  end

  manifest.send :save
end