(kbd/load-font "/home/user/.nix-profile/share/fonts/noto/NotoSans[wdth,wght].ttf")

(define state #f)

(kbd/defclass en (latin)
  ((init) (set! state 'lower))
  ((state) (or 'state 'lower))
  ((show-upper) (or (symbol=? (self state) 'upper) (symbol=? (self state) 'capslock)))
  ((show-lower) (symbol=? (self state) 'lower))
  ((show-symbols) (symbol=? (self state) 'symbols))
  ((show-numbers) (symbol=? (self state) 'numbers))
  ((show-preferences) (symbol=? (self state) 'preferences))

  ((rows)
     (cond
       ((self show-upper)   '((Q W E R T Y U I O P)
                              (A S D F G H J K L)
                              (Shift_L Z X C V B N M BackSpace)
                              (show_numbers preferences space "." Return)))
       ((self show-symbols) '((~ "`" "|" "·" √ π τ "÷" "×" "¶")
                              ("©" "®" "£" € "¥" ^ "°" * "{" "}")
                              (show_numbers_from_symbols \ / < > = "[" "]" BackSpace)
                              (show_letters preferences space "." Return)))
       ((self show-numbers) '((1 2 3 4 5 6 7 8 9 0)
                              ("@" "#" $ % & - _ + "(" ")")
                              (show_symbols "," "\"" "'" : ";" ! ? BackSpace)
                              (show_letters preferences space "." Return)))
       (else                '((q w e r t y u i o p)
                              (a s d f g h j k l)
                              (Shift_L z x c v b n m BackSpace)
                              (show_numbers preferences space "." Return)))))

  ; 1 unit = keyboard width / total units in this row
  ((button-width sym)
    (cond
      ((equal? sym 'Shift_L) 13.0)
      ((equal? sym 'BackSpace) 13.0)
      ((equal? sym 'show_numbers) 13.0)
      ((equal? sym 'show_letters) 13.0)
      ((equal? sym 'space) 54.0)
      ((equal? sym 'Return) 13.0)
      (else 10.0)))

  ((button-padding sym)
    (cond
      ((equal? sym 'a) (cons 5.0 0.0))
      ((equal? sym 'l) (cons 0.0 5.0))
      (else (cons 0.0 0.0))))

  ((make-button sym x y w h)
    (let ((sym (if (symbol? sym) (symbol->string sym) sym)))
      (list sym (kbd/make-text (cons x y) (cons w h) sym "Noto Sans" 74))))

  ((make-row syms y width height)
    (let ((total-x (apply + (map (lambda (sym)
                                   (let ((pad (self button-padding sym))
                                         (width (self button-width sym)))
                                     (+ width (car pad) (cdr pad))))
                                 syms))))
      (define (scale u) (/ (* u width) total-x))
      (define (calc x syms)
        (if (null? syms)
            '()
            (let* ((sym (car syms))
                   (pad1 (self button-padding sym))
                   (pad (cons (scale (car pad1)) (scale (cdr pad1))))
                   (w (scale (self button-width sym))))
              (cons (self make-button sym (+ x (car pad)) y w height)
                    (calc (+ x (car pad) w (cdr pad)) (cdr syms))))))
      (calc 0 syms)))

  ((height) 500.0)

  ((make-layout rows kbd-width)
    (define (height-list start end offset)
      (if (> start end) '() (cons start (height-list (+ start offset) end offset))))
    (define (append-all lists) (apply append lists))
    (let*
      ((height (self height))
       (row-height (/ height (length rows)))
       (button-rows (map (lambda (row y) (self make-row row y kbd-width row-height))
                         (reverse rows)
                         (height-list 0 height row-height))))
    (kbd/make-layout (cons (list "!bg" (kbd/make-rect (cons 0 0) (cons kbd-width height))) (append-all button-rows)))))

  ((kbd-layout)
   (self make-layout (self rows) (kbd/width)))

  ; signals

  ((kbd/width-changed)
   (kbd/set-layout (self kbd-layout))))