#lang racket/base

(define (listener port)
  (transition 'no-state
    (role/act (tcp-listener port)
	      #:topic t
	      #:on-presence (spawn (connection-handler t))))))

(define (connection-handler topic)
  (define-values (cin cout in-topic out-topic) (tcp-accept topic))
  (transition 'no-state
    (cin (tcp-credit 1) #:mode 'feedback)
    (role/act in-topic
      [(tcp-channel _ _ (or (== #"\4") (? eof-object?)))
       (kill)]
      [(tcp-channel _ _ (? bytes? bytev))
       (list (cin (tcp-credit 1) #:mode 'feedback)
	     (cout bytev))])))

(define (main port)
  (ground-vm
   (transition 'no-state
     (spawn tcp-driver)
     (spawn (listener port)))))

(main 5999)

(define (tcp-accept topic)
  (match-define (topic (tcp-channel remote-addr local-addr _)) topic)
  (values (match-lambda
	    [(val #:mode 'feedback)
	     (send-feedback (tcp-channel remote-addr local-addr val))])
	  (match-lambda
	    [(val)
	     (send-message (tcp-channel local-addr remote-addr val))])
	  (topic-subscriber (tcp-channel remote-addr local-addr (wild)))
	  (topic-publisher (tcp-channel local-addr remote-addr (wild)))))


(define (tcp-listener port)
  (topic-subscriber (tcp-channel (wild)
				 (tcp-local-endpoint port)
				 (wild))
		    #:monitor? #t))

(require racket/string)
(require racket/set)
(require racket/match)
(require "os2.rkt")
(require "os2-tcp.rkt")
(require "os2-tcp-helper.rkt")