;; echo client

(use-modules (ice-9 optargs))
(use-modules (ice-9 getopt-long))
(use-modules (ice-9 rdelim))

(define (hostname->ip hostname)
  "Convert HOSTNAME to its IP.
e.g.,
    (hostname->ip \"www.google.com\")  => \"64.233.189.104\""
  (inet-ntop AF_INET (car (hostent:addr-list (gethost hostname)))))


(define (main args)
  (let* ((option-spec '((help (single-char #\h) (value #f))
                        (host (single-char #\H) (value #t))
                        (port (single-char #\p) (value #t))))
         (options (getopt-long args option-spec)))
    (if (option-ref options 'help #f)
        (usage)
        (client (option-ref options 'host "localhost")
                (option-ref options 'port "10000")))))

(define (usage)
  (display "\
Usage: client.scm [OPTIONS]
  -h, --help              show this help
  -H, --host=LOCALHOST    remote address
  -p, --port=10000        remote port
")
  (exit 1))

(define (client host port)
  (let ((s (socket PF_INET SOCK_STREAM 0))
        (host-ip (hostname->ip host))
        (port-value (string->number port)))
    (connect s AF_INET (inet-pton AF_INET host-ip) port-value)
    (display "connected to server\n")
    (echo-loop s)))

(define (echo-loop server-port)
  (let ((line (read-line (current-input-port) 'concat)))
    (while (not (eof-object? line))
           (display line server-port)
           (display (read-line server-port 'concat))
           (set! line (read-line (current-input-port) 'concat)))
    (close server-port)))

;;; client.scm ends here