learnjin/rewritten

require 'rack'

module Rack
  module Rewritten
    class Subdomain
      def initialize(app, *fqdns)
        @app = app
        @fqdns = fqdns
      end

      def call(env)
        puts '-> Rack::Rewritten::Subdomain'
        req = Rack::Request.new(env)

        @fqdns.each do |n|
          if req.host =~ /(.+)\.#{n}$/
            if Regexp.last_match(1) == 'www'
              break
            else
              env['SUBDOMAIN'] = Regexp.last_match(1)
              env['FQDN'] = n
              break
            end
          end
        end

        @app.call(env)
      end
    end
  end
end