# use with::
#
# use CacheSettings, {
#   /\/static\// =>
#      { :cache_control => "max-age=86400, public",
#       :expires => 86400
#     }
# }
# use Rack::Static, :urls => ["/static"] # for example

class CacheSettings
  def initialize app, pat
    @app = app
    @pat = pat
  end
  def call env
    res = @app.call(env)
    path = env["REQUEST_PATH"]
    @pat.each do |pattern,data|
      if path =~ pattern
        res[1]["Cache-Control"] = data[:cache_control] if data.has_key?(:cache_control)
        res[1]["Expires"] = (Time.now + data[:expires]).utc.rfc2822 if data.has_key?(:expires)
        return res
      end
    end
    res
  end
end