(in-package :smsg-network)

(defun command-loop (in out route)
  (loop (let ((command (read-sexp in)))
	  (when (not (handle-inbound-command command in out route))
	    (return)))))

(defun handle-inbound-command (command in out route)
  (ematch-sexp command
    (("subscribe" filter sink name reply-sink reply-name)
     (if (rebind-node filter nil route)
	 (when (plusp (length reply-sink))
	   (post reply-sink reply-name (sexp-build ("subscribe-ok" (= filter)))))
	 (report! `(rebind-failed ,command))))
    (("unsubscribe" id)
     (when (not (rebind-node id route nil))
       (report! `(rebind-failed ,command))))
    (("post" name body token)
     (send name body))))

(defun relay (in out localname servermode)
  (flet ((route (message)
	   (write-sexp message out)
	   (write-byte 13 out)
	   (write-byte 10 out)))
    (if servermode
	(route (sexp-quote ("hop" "0")))
	(ematch-sexp (read-sexp in)
	  (("hop" "0") t)))
    (force-output out)
    (route (sexp-build ("subscribe" (= localname) "" "" "" "")))
    (command-loop in out #'route)))

(defun handle-connection (stream)
  (relay stream stream (sexp-quote "smsg") t))

(defun serve-on-port (port)
  (usocket:socket-server "localhost" port 'handle-connection '()
			 :in-new-thread t
			 :multi-threading t
			 :reuse-address t
			 :element-type '(unsigned-byte 8)))

(defun client (localname hostname portnumber)
  (let ((s (usocket:socket-stream
	    (usocket:socket-connect hostname portnumber :element-type '(unsigned-byte 8)))))
    (relay s s localname nil)))