;;; ll-box --- luki boxes -*- lexical-binding: t -*-
;;
;;; Commentary:
;;
;;; Code:

(require 'cl-lib)
(cl-pushnew "." load-path :test #'string=)
(require 'll)

(-> 'll-button)

(cl-defstruct ll-box
  (x 0                                 :type integer)
  (y 0                                 :type integer)
  (w 8                                 :type integer)
  (h 8                                 :type integer)
  (data [97 98 99 100 101 102 103 104] :type array))

(cl-defmethod ll-box-size ((b ll-box))
  (* (ll-box-w b) (ll-box-h b)))

(cl-defmethod ll-box-draw-at ((b ll-box) x y di &optional border)
  (when-let* ((chr (cl-case border
                      (-1 (or 9623 9581))
                      ( 0 (or 9604 9472))
                      (-2 (or 9622 9582))
                      ( 1 (or 9612 9474))
                      (-3 (or 9624 9583))
                      ( 2 (or 9600 9472))
                      (-4 (or 9629 9584))
                      ( 3 (or 9616 9474))
                      (t (aref (ll-box-data b) (m di (--- (ll-box-data b)))))))
              (chr-str (char-to-string chr))
              (col     (cond
                        (border     `(:foreground "#199696"))
                        ((= chr 32) `(:background "#6464ff"))
                        (`(:foreground "#32afaf" :background "#3264ff")))))
    (goto-char (+ (pos-bol (+ (line-number-at-pos (point-min)) (- y (line-number-at-pos)))) x))
    (@i (propertize chr-str 'face col))
    (delete-char 1)))

(cl-defmethod ll-box-draw ((b ll-box))
  (cl-loop
   for i from 0 below (ll-box-size b)
   for x-idx  = (m i (ll-box-w b))
   for y-idx  = (/ i (ll-box-w b))
   for top    = (z y-idx)
   for left   = (z x-idx)
   for right  = (= 1 (- (ll-box-w b) x-idx))
   for down   = (= 1 (- (ll-box-h b) y-idx))
   for border = (cond ((& top  left)  -1)
                      ((& top  right) -2)
                      ((& down right) -3)
                      ((& down left)  -4)
                      (top             0)
                      (right           1)
                      (down            2)
                      (left            3))
   for x      = (+ (ll-box-x b) x-idx)
   for y      = (+ (line-number-at-pos (point-min)) (ll-box-y b) y-idx)
   do (ll-box-draw-at b x y i border)
   finally
     (goto-char (+ (pos-bol 2) (ll-box-x b)))
     (delete-char 23)
     (ll-insert-button "<" (L (_) (-- (ll-box-x b))) nil) (@i 32)
     (ll-insert-button "^" (L (_) (-- (ll-box-y b))) nil) (@i 32)
     (ll-insert-button "v" (L (_) (++ (ll-box-y b))) nil) (@i 32)
     (ll-insert-button ">" (L (_) (++ (ll-box-x b))) nil)))

(defvar ll-box-lb nil)

(defun ll-box-draw-init ()
  (cl-loop
   initially (new-buf "*ll-box-draw*")
   (or (ll-box-p ll-box-lb) (setf ll-box-lb (make-ll-box :x 8 :y 5 :w 23 :h 12 :data [108 108 45 98 111 120 32 32])))
   repeat 28 do (@i (propertize (make-string 98 183) 'face `(:foreground "#643296")) 10)
   finally          (ll-box-draw ll-box-lb)))

;; test: (ll-box-draw-init)

(<- 'll-box)
;;; ll-box.el ends here