#! /usr/bin/env scheme-script
;; -*- mode: scheme -*-
;;
;; Copyright 2016 Aldo Nicolas Bruno
;;
;; Licensed under the Apache License, Version 2.0 (the "License");
;; you may not use this file except in compliance with the License.
;; You may obtain a copy of the License at
;;
;;     http://www.apache.org/licenses/LICENSE-2.0
;;
;; Unless required by applicable law or agreed to in writing, software
;; distributed under the License is distributed on an "AS IS" BASIS,
;; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
;; See the License for the specific language governing permissions and
;; limitations under the License.

;
; example of remote REPL
; you can use any transport, tcp:// ipc:// websocket inproc
; see http://nanomsg.org/v1.0.0/nanomsg.7.html
; and nanomsg.sls for details
;
; ./local-repl tcp://127.0.0.1:12345
; ABC
;
; meanwhile in another terminal...
; ./remote-repl tcp://127.0.0.1:12345
; > (+ 1 2)
; 3
; > (printf "ABC~n") --> will print ABC on the local repl process
;
; The nice thing is that you can scale to any protocol and
; that it can be integrated in an event/main loop
; it uses non-blocking (read) and you invoke (my-local-repl) until => #f
;
; TODO: add a command for local exit. #!eof object will only close the remote 
; connection....

#!chezscheme

(import (chezscheme) (nanomsg))
(nanomsg-library-init)

(define argv (command-line-arguments))

(define sock (nn-socket AF_SP NN_REP))
(define eid (nn-bind sock (car argv)))

(define (my-local-repl)
  (call/cc 
   (lambda (return)
     (let* ([buf (box #t)]
	    [r (nn-recv sock buf NN_MSG NN_DONTWAIT)])
       (when r
	     (guard (e [else (printf "error in eval ~d~n" e)])
		    (with-input-from-string (utf8->string (unbox buf))
		      (lambda ()
			(let ([pr (call-with-string-output-port
				   (lambda (p)
				     (let ([token (read)])
				       (if #f;(eof-object? token) 
					   (return #f)
					   (pretty-print 
					    (eval token 
						  (interaction-environment)) p)))))])
			  (nn-send sock (string->utf8 pr) 0)))))))
     #t)))

(let loop () 
  (when (my-local-repl)
	(sleep (make-time 'time-duration 1000000 0))
	(loop)))
