;; https://invisible-island.net/xterm/ctlseqs/ctlseqs.html

;; Clear the screen better:
;; https://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h2-The-Alternate-Screen-Buffer

(define csi-lead "\x1b[")

(define (str-csi . args)
  (apply string-append csi-lead args))

(define (csi-command! . args)
  (write-string (apply str-csi args))
  (flush-output-port))

; These are xterm things, but they are widely adopted
(define (enable-alternate-buffer!)
  (csi-command! "?1049h"))
(define (disable-alternate-buffer!)
  (csi-command! "?1049l"))

(define (erase-screen!) (csi-command! "2J"))

(define (move-cursor! x y)
  "Also valid with CSI<L>;<C>f being <L> and <C> line number and column
  number respectively. In ttys, cursor starts at 1,1"
  (csi-command! (number->string (+ y 1)) ";" (number->string (+ 1 x)) "H"))

(define (ui-initialize!)
  (enable-alternate-buffer!)
  (move-cursor! 0 0))

(define (ui-deinitialize!)
  (disable-alternate-buffer!))