#lang syndicate
;;; SPDX-License-Identifier: LGPL-3.0-or-later
;;; SPDX-FileCopyrightText: Copyright © 2021-2024 Tony Garnock-Jones <tonyg@leastfixedpoint.com>

(module+ main
  (require racket/cmdline)
  (require (only-in racket/port read-line-evt))
  (require syndicate/drivers/tcp)
  (require syndicate/drivers/racket-event)

  (define host "127.0.0.1")
  (define port 5999)

  (command-line #:once-each
                [("--host" "-H") hostname "Set hostname to connect to"
                 (set! host hostname)]
                [("--port" "-p") port-number "Set port number to connect to"
                 (set! port (string->number port-number))])

  (standard-actor-system (ds)
    (with-services [syndicate/drivers/racket-event]
      (establish-connection
       ds (TcpRemote host port)
       #:initial-mode (Mode-lines (LineMode-lf))
       #:on-connect (lambda (source sink)
                      (at ds
                        (on (message (RacketEvent (read-line-evt (current-input-port)) $vs))
                          (match (car vs)
                            [(? eof-object?) (stop-current-facet (log-info "EOF on stdin."))]
                            [line (send-line sink line)]))))
       #:on-rejected (lambda (message) (stop-current-facet (log-error "~a" message)))
       #:on-disconnect (lambda () (stop-current-facet (log-info "Disconnected")))
       #:on-data (lambda (line _mode)
                   ;; \e7        DECSC, save cursor position
                   ;; \n\e[A     Force a new line if at end of screen, then back up; effect of \r
                   ;; \e[L       Insert a line here, pushing the current line's contents down one
                   ;; ~a         Placeholder for the incoming line
                   ;; \e8        DECRC, Restore cursor - it will be one line too high
                   ;; \e[B       Correct for the one line to high
                   (printf "\e7\n\e[A\e[L~a\e8\e[B" line)
                   (flush-output))))))