#lang racket/base

(require "os-big-bang.rkt")
(require "os-udp.rkt")
(require "os-timer.rkt" racket/match)

(define getter
  (os-big-bang 'none
    (send-message `(request create-echo-socket (udp new 0 65536)))
    (subscribe/fresh sub
      (message-handlers w
	[`(reply create-echo-socket ,sname)
	 (transition w
	   (unsubscribe sub)
	   (send-message (udp-packet sname (udp-address "127.0.0.1" 5678) #"get"))
	   (send-message (set-timer 'timeout 500 #t))
	   (subscribe 'reply-waiter
	     (message-handlers w
	       [(udp-packet source (== sname) reply-bytes)
		(define counter (integer-bytes->integer reply-bytes #f))
		(write counter)
		(newline)
		(transition w
		  (send-message 'quit)
		  (unsubscribe 'reply-waiter))]
	       [(timer-expired 'timeout _)
		(write 'timed-out)
		(newline)
		(transition w
		  (send-message 'quit)
		  (unsubscribe 'reply-waiter))])))]))))

(ground-vm
 (os-big-bang 'none
   (spawn (os-big-bang 'none
	    (subscribe 'quit-waiter
	      (message-handlers w
		['quit
		 (exit)]))))
   (spawn udp-driver)
   (spawn (timer-driver))
   (spawn getter)))