class Goliath::Rack::Render

def get_content_type(env)
  type = if env.respond_to? :params
    fmt = env.params['format']
    fmt = fmt.last if fmt.is_a?(Array)
    if !fmt.nil? && fmt !~ /^\s*$/
      ::Rack::RespondTo::MediaType(fmt)
    end
  end
  
  type = ::Rack::RespondTo.env['HTTP_ACCEPT'] if type.nil?
  type = ::Rack::RespondTo.selected_media_type if type == '*/*'
  "#{type}; charset=utf-8"
end

def initialize(app, types = nil)
  @app = app
  ::Rack::RespondTo.media_types = [types].flatten if types
end

def post_process(env, status, headers, body)
  ::Rack::RespondTo.env = env
  # the respond_to block is what actually triggers the
  # setting of selected_media_type, so it's required
  respond_to do |format|
    ::Rack::RespondTo.media_types.each do |type|
      format.send(type, Proc.new { body })
    end
  end
  extra = { 'Content-Type' => get_content_type(env),
            'Vary' => [headers.delete('Vary'), 'Accept'].compact.join(',') }
  [status, extra.merge(headers), body]
end