#!r6rs
(library (rsc3 osc transport)
(export open-tcp close-transport
	osc-send osc-recv osc-request)
(import (rnrs)
	(rnrs bytevectors)
	(ikarus)
	(rsc3 osc decode)
	(rsc3 osc encode)
	(rsc3 u8 encode)
	(rsc3 u8 decode))

(define-record-type transport (fields type ip op))

(define (tcp-transport? t)
  (eq? (transport-type t) 'tcp))

(define (udp-transport? t)
  (eq? (transport-type t) 'tcp))

(define (open-tcp h p)
  (let-values (((op ip) (tcp-connect h p)))
    (make-transport 'tcp ip op)))

(define (close-transport t)
  (close-input-port (transport-ip t))
  (close-output-port (transport-op t)))

(define (put-bytevector* p v)
  (let ((n (bytevector-length v)))
    (let loop ((i 0))
      (if (= i n)
	  #f
	  (let ((b (bytevector-u8-ref v i)))
	    (put-u8 p b)
	    (loop (+ i 1)))))))

(define (osc-send t m)
  (let ((p (transport-op t))
	(v (encode-osc m)))
    (cond ((tcp-transport? t)
	   (put-bytevector* p (encode-i32 (bytevector-length v)))
	   (put-bytevector* p v))
	  (else
	   (error 'osc-send "unknown transport")))))

(define (osc-recv t _)
  (error 'osc-recv "unknown transport"))

(define (osc-request u r m t)
  (osc-send u m)
  (let ((p (osc-recv u t)))
    (if (and p (string=? (car p) r)) p #f)))

)