(use (prefix glfw3 glfw:)
     (prefix opengl-glew gl:)
     (prefix nuklear nk:)
     (rename format (format cl-format))
     srfi-1 posix)

(require-library nuklear-glfw-opengl2)
(import (prefix nuklear-glfw-opengl2 backend:))

(define width 1200)
(define height 800)

(glfw:init)
(glfw:make-window width height "Overview")
(glfw:make-context-current (glfw:window))
(set!-values (width height) (glfw:get-window-size (glfw:window)))

(define context (backend:init! (glfw:window) #t))
(backend:init-font!)

(define background (nk:rgb->color 28 48 62))

(define show-menu? #t)
(define titlebar? #t)

(define border? #t)
(define scalable? #t)
(define movable? #t)
(define no-scrollbar? #f)
(define minimizable? #t)
(define closable? #t)

(define menu-progress 60)
(define menu-slider 10)
(define menu-check #t)

(define progress 40)
(define slider 10)
(define check #t)

(define A 0)
(define B 1)
(define C 2)

(define checkbox #f)
(define option 0)

(define int-slider 5)
(define float-slider 2.5)
(define prog-value 40)
(define property-float 2)
(define property-int 10)
(define property-neg 10)

(define range-float-min 0)
(define range-float-max 100)
(define range-float-value 50)
(define range-int-min 0)
(define range-int-value 2048)
(define range-int-max 4096)
(define ratio '(120 150))

(define selected-list (make-vector 4 #f))
(define selected-grid (make-vector 16 #f))

(define (vector-for-each proc vec)
  (let loop ((i 0))
    (when (< i (vector-length vec))
      (proc i (vector-ref vec i))
      (loop (add1 i)))))

(define (vector-toggle! vec n)
  (let ((value (vector-ref vec n)))
    (vector-set! vec n (not value))))

(define chart-selection 8)
(define check-values (make-list 4 #f))
(define position '(0 0 0))
(define combo-color (nk:make-color 130 50 50 255))
(define combo-color2 (nk:make-color 130 180 50 255))
(define use-hsva? #f)
(define prog-a 20)
(define prog-b 40)
(define prog-c 10)
(define prog-d 90)
(define weapons '("Fist" "Pistol" "Shotgun" "Plasma" "BFG"))
(define current-weapon (car weapons))

(define time-selected? #f)
(define date-selected? #f)
(define selected-time #f)
(define selected-date #f)

(define text (make-vector 8 ""))
(define field-buffer "")
(define box-buffer "")

(define (mask-text text)
  (make-string (string-length text) #\*))

(define pi (* 2 (asin 1)))
(define col-index -1)
(define line-index -1)

(define selected (make-list 4 #f))
(define color (nk:make-color 255 0 0 255))
(define popup-active? #f)

(define group-titlebar? #f)
(define group-border? #t)
(define group-no-scrollbar? #f)

(define (group-flags)
  (append (if group-titlebar? '(title) '())
          (if group-border? '(border) '())
          (if group-no-scrollbar? '(no-scrollbar) '())))

(define group-width 320)
(define group-height 200)

(define selected-group (make-list 16 #f))

(define left-selected-group (make-list 32 #f))
(define top-right-selected-group (make-list 4 #f))
(define center-right-selected-group (make-list 4 #f))
(define bottom-right-selected-group (make-list 4 #f))

(define vertical-a 100)
(define vertical-b 100)
(define vertical-c 100)

(define horizontal-a 100)
(define horizontal-b 100)
(define horizontal-c 100)

(define (window-flags)
  (append (if border? '(border) '())
          (if scalable? '(scalable) '())
          (if movable? '(movable) '())
          (if no-scrollbar? '(no-scrollbar) '())
          (if minimizable? '(minimizable) '())
          (if closable? '(closable) '())))

(nk:style-window-header-align-set! (nk:context-style context) #t)

(define show-app-about? #f)

(define layout (nk:make-panel))
(define menu-layout (nk:make-panel))
(define popup-layout (nk:make-panel))
(define combo-layout (nk:make-panel))
(define tab-layout (nk:make-panel))
(define sub-layout (nk:make-panel))

(let loop ()
  (when (and (not (glfw:window-should-close (glfw:window))))
    (glfw:poll-events)
    (backend:new-frame)

    (when (nk:window-begin context layout "Overview"
                           (nk:make-rect 10 10 400 750)
                           (window-flags))
      (when show-menu?
        (nk:menubar-begin context)
        (nk:layout-row-begin context #f 25 2)
        (nk:layout-row-push context 45)
        (when (nk:menu-begin-label context menu-layout "MENU" 'left 120)
          (nk:layout-row-dynamic context 25 1)
          (when (nk:menu-item-label context "Hide" 'left)
            (set! show-menu? #f))
          (when (nk:menu-item-label context "About" 'left)
            (set! show-app-about? #t))
          (set! progress (nk:progressbar context progress 100 #t))
          (set! slider (nk:slider-int context 0 slider 16 1))
          (set! check (nk:checkbox-label context "check" check))
          (nk:menu-end context))
        (nk:layout-row-push context 70)
        (set! menu-progress (nk:progressbar context menu-progress 100 #t))
        (set! menu-slider (nk:slider-int context 0 menu-slider 16 1))
        (set! menu-check (nk:checkbox-label context "check" menu-check))
        (nk:menubar-end context))

      (when show-app-about?
        (if (nk:popup-begin context popup-layout #f "About" 'closable (nk:make-rect 20 100 300 190))
            (begin
              (nk:layout-row-dynamic context 20 1)
              (nk:label context "Nuklear" 'left)
              (nk:label context "By Micha Mettke" 'left)
              (nk:label context "nuklear is licensed under the public domain License" 'left)
              (nk:popup-end context))
            (set! show-app-about? #f)))

      (when (nk:tree-push context #t "Window" #f)
        (nk:layout-row-dynamic context 30 2)
        (set! titlebar? (nk:checkbox-label context "Titlebar" titlebar?))
        (set! show-menu? (nk:checkbox-label context "Menu" show-menu?))
        (set! border? (nk:checkbox-label context "Border" border?))
        (set! scalable? (nk:checkbox-label context "Resizable" scalable?))
        (set! movable? (nk:checkbox-label context "Movable" movable?))
        (set! no-scrollbar? (nk:checkbox-label context "No Scrollbar" no-scrollbar?))
        (set! minimizable? (nk:checkbox-label context "Minimizable" minimizable?))
        (set! closable? (nk:checkbox-label context "Closable" closable?))
        (nk:tree-pop context))

      (when (nk:tree-push context #t "Widgets" #f)
        (when (nk:tree-push context #f "Text" #f)
          (nk:layout-row-dynamic context 20 1)
          (when (nk:button-label context "GC")
            (gc #t))
          (nk:label context "Label aligned left" 'left)
          (nk:label context "Label aligned centered" 'centered)
          (nk:label context "Label aligned right" 'right)
          (nk:label-colored context "Blue text" 'left (nk:rgb->color 0 0 255))
          (nk:label-colored context "Yellow text" 'left (nk:rgb->color 255 255 0))
          ;; NOTE: no nk:text because passing strings with NULL is
          ;; hard and might end up forbidden in strings in CHICKEN 5

          (nk:layout-row-static context 100 200 1)
          (nk:label-wrap context "This is a very long line to hopefully get this text to be wrapped into multiple lines to show line wrapping")
          (nk:layout-row-dynamic context 100 1)
          (nk:label-wrap context "This is another long text to show dynamic window changes on multiline text")

          (nk:tree-pop context))

        (when (nk:tree-push context #f "Button" #f)
          (nk:layout-row-static context 30 100 3)
          (when (nk:button-label context "Button")
            (printf "Button pressed!\n"))
          (when (nk:button-label context "Repeater" #t)
            (printf "Repeater is being pressed!\n"))
          (nk:button-color context (nk:rgb->color 0 0 255))

          (nk:layout-row-static context 20 20 8)
          (nk:button-symbol context 'circle)
          (nk:button-symbol context 'circle-filled)
          (nk:button-symbol context 'rect)
          (nk:button-symbol context 'rect-filled)
          (nk:button-symbol context 'triangle-up)
          (nk:button-symbol context 'triangle-down)
          (nk:button-symbol context 'triangle-left)
          (nk:button-symbol context 'triangle-up)

          (nk:layout-row-static context 30 100 2)
          (nk:button-symbol-label context 'triangle-left "prev" 'right)
          (nk:button-symbol-label context 'triangle-right "prev" 'left)

          (nk:tree-pop context))

        (when (nk:tree-push context #f "Basic" #f)
          (nk:layout-row-static context 30 100 1)
          (set! checkbox (nk:checkbox-label context "Checkbox" checkbox))

          (nk:layout-row-static context 30 80 3)
          (set! option (if (nk:option-label context "optionA" (= option A)) A option))
          (set! option (if (nk:option-label context "optionB" (= option B)) B option))
          (set! option (if (nk:option-label context "optionC" (= option C)) C option))

          (nk:layout-row context #f 30 ratio)
          (nk:label context "Slider int" 'left)
          (set! int-slider (nk:slider-int context 0 int-slider 10 1))

          (nk:label context "Slider float" 'left)
          (set! float-slider (nk:slider-float context 0 float-slider 5 0.5))
          (nk:label context (format "Progressbar: ~a" prog-value) 'left)
          (set! prog-value (nk:progressbar context prog-value 100 #t))

          (nk:layout-row context #f 25 ratio)
          (nk:label context "Property float:" 'left)
          (set! property-float (nk:property-float context "Float:" 0 property-float 64 0.1 0.2))
          (nk:label context "Property int:" 'left)
          (set! property-int (nk:property-int context "Int:" 0 property-int 100 1 1))
          (nk:label context "Property neg:" 'left)
          (set! property-neg (nk:property-int context "Neg:" -10 property-neg 10 1 1))

          (nk:layout-row-dynamic context 25 1)
          (nk:label context "Range:" 'left)
          (nk:layout-row-dynamic context 25 3)
          (set! range-float-min (nk:property-float context "#min:" 0 range-float-min range-float-max 1 0.2))
          (set! range-float-value (nk:property-float context "#float:" range-float-min range-float-value range-float-max 1 0.2))
          (set! range-float-max (nk:property-float context "#max:" range-float-min range-float-max 100 1 0.2))

          (set! range-int-min (nk:property-int context "#min:" -32767 range-int-min range-int-max 1 10))
          (set! range-int-value (nk:property-int context "#neg:" range-int-min range-int-value range-int-max 1 10))
          (set! range-int-max (nk:property-int context "#max:" range-int-min range-int-max 32767 1 10))

          (nk:tree-pop context))

        (when (nk:tree-push context #f "Selectable" #f)
          (when (nk:tree-push context #f "List" #f)
            (nk:layout-row-static context 18 100 1)
            (vector-set! selected-list 0 (nk:selectable-label context "Selectable" 'left (vector-ref selected-list 0)))
            (vector-set! selected-list 1 (nk:selectable-label context "Selectable" 'left (vector-ref selected-list 1)))
            (nk:label context "Not selectable" 'left)
            (vector-set! selected-list 2 (nk:selectable-label context "Selectable" 'left (vector-ref selected-list 2)))
            (vector-set! selected-list 3 (nk:selectable-label context "Selectable" 'left (vector-ref selected-list 3)))
            (nk:tree-pop context))

          (when (nk:tree-push context #f "Grid" #f)
            (nk:layout-row-static context 50 50 4)
            (vector-for-each
             (lambda (i x)
               (receive (value clicked?) (nk:selectable-label context "Z" 'centered x)
                        (vector-set! selected-grid i value)
                        (when clicked?
                          (let ((x (modulo i 4))
                                (y (quotient i 4)))
                            (when (> x 0)
                              (vector-toggle! selected-grid (sub1 i)))
                            (when (< x 3)
                              (vector-toggle! selected-grid (add1 i)))
                            (when (> y 0)
                              (vector-toggle! selected-grid (- i 4)))
                            (when (< y 3)
                              (vector-toggle! selected-grid (+ i 4)))))))
             selected-grid)
            (nk:tree-pop context))

          (nk:tree-pop context))

        (when (nk:tree-push context #f "Combo" #f)
          (nk:layout-row-static context 25 200 1)
          (when (nk:combo-begin-label context combo-layout current-weapon
                                      (nk:combo-items-height context (length weapons) 25))
            (nk:layout-row-dynamic context 25 1)
            (for-each
             (lambda (weapon)
               (when (nk:combo-item-label context weapon 'left)
                 (set! current-weapon weapon)))
             weapons)
            (nk:combo-end context))

          (when (nk:combo-begin-color context combo-layout combo-color 200)
            (nk:layout-row context #t 30 '(0.15 0.85))
            (nk:label context "R:" 'left)
            (nk:color-r-set! combo-color (nk:slider-int context 0 (nk:color-r combo-color) 255 5))
            (nk:label context "G:" 'left)
            (nk:color-g-set! combo-color (nk:slider-int context 0 (nk:color-g combo-color) 255 5))
            (nk:label context "B:" 'left)
            (nk:color-b-set! combo-color (nk:slider-int context 0 (nk:color-b combo-color) 255 5))
            (nk:label context "A:" 'left)
            (nk:color-a-set! combo-color (nk:slider-int context 0 (nk:color-a combo-color) 255 5))
            (nk:combo-end context))

          (when (nk:combo-begin-color context combo-layout combo-color2 400)
            (nk:layout-row-dynamic context 120 1)
            (set! combo-color2 (nk:color-picker context combo-color2))

            (nk:layout-row-dynamic context 25 2)
            (set! use-hsva? (if (nk:option-label context "RGB" (not use-hsva?)) #f use-hsva?))
            (set! use-hsva? (if (nk:option-label context "HSV" use-hsva?) #t use-hsva?))

            (nk:layout-row-dynamic context 25 1)
            (if use-hsva?
                (let* ((hsva-values (nk:color->hsva-ints combo-color2))
                       (hsva-values*
                        (map
                         (lambda (value label)
                           (nk:property-int context label 0 value 255 1 1))
                         hsva-values '("#H:" "#S:" "#V:" "#A:"))))
                  (set! combo-color2 (apply nk:hsva->color hsva-values*)))
                (begin
                  (nk:color-r-set! combo-color2 (nk:property-int context "#R:" 0 (nk:color-r combo-color2) 255 1 1))
                  (nk:color-g-set! combo-color2 (nk:property-int context "#G:" 0 (nk:color-g combo-color2) 255 1 1))
                  (nk:color-b-set! combo-color2 (nk:property-int context "#B:" 0 (nk:color-b combo-color2) 255 1 1))
                  (nk:color-a-set! combo-color2 (nk:property-int context "#A:" 0 (nk:color-a combo-color2) 255 1 1))))
            (nk:combo-end context))

          (let ((sum (+ prog-a prog-b prog-c prog-d)))
            (when (nk:combo-begin-label context combo-layout (number->string sum) 200)
              (nk:layout-row-dynamic context 30 1)
              (set! prog-a (nk:progressbar context prog-a 100 #t))
              (set! prog-b (nk:progressbar context prog-b 100 #t))
              (set! prog-c (nk:progressbar context prog-c 100 #t))
              (set! prog-d (nk:progressbar context prog-d 100 #t))
              (nk:combo-end context)))

          (let ((sum (count identity check-values)))
            (when (nk:combo-begin-label context combo-layout (number->string sum) 200)
              (nk:layout-row-dynamic context 30 1)
              (set! check-values
                    (map
                     (lambda (checked? weapon)
                       (nk:checkbox-label context weapon checked?))
                     check-values weapons))
              (nk:combo-end context)))

          (let ((label (cl-format #f "~{~,2f~^, ~}" position)))
            (when (nk:combo-begin-label context combo-layout label 200)
              (nk:layout-row-dynamic context 25 1)
              (set! position
                    (map
                     (lambda (component label)
                       (nk:property-float context label -1024 component 1024 1 0.5))
                     position '("#X:" "#Y:" "#Z:")))
              (nk:combo-end context)))

          (let ((label (cl-format #f "~,2f" chart-selection)))
            (when (nk:combo-begin-label context combo-layout label 250)
              (nk:layout-row-dynamic context 150 1)
              (let* ((values #(26 13 30 15 25 10 20 40 12 8 22 28 5))
                     (size (vector-length values)))
                (nk:chart-begin context #f size 0 50)
                (vector-for-each
                 (lambda (_i x)
                   (let ((events (nk:chart-push context x)))
                     (when (memv 'clicked events)
                       (set! chart-selection x)
                       (nk:combo-close context))))
                 values)
                (nk:chart-end context))
              (nk:combo-end context)))

          (when (not time-selected?)
            (set! selected-time (seconds->local-time)))
          (when (not date-selected?)
            (set! selected-date (seconds->local-time)))

          (let ((label (time->string selected-time "%H:%M:%S")))
            (when (nk:combo-begin-label context combo-layout label 400)
              (set! time-selected? #t)
              (nk:layout-row-dynamic context 25 1)
              (vector-set! selected-time 0 (nk:property-int context "#S:" 0 (vector-ref selected-time 0) 59 1 1))
              (vector-set! selected-time 1 (nk:property-int context "#M:" 0 (vector-ref selected-time 1) 59 1 1))
              (vector-set! selected-time 2 (nk:property-int context "#S:" 0 (vector-ref selected-time 2) 23 1 1))
              (nk:combo-end context)))

          (nk:layout-row-static context 25 350 1)
          (let ((label (time->string selected-date "%d-%m-%Y")))
            (when (nk:combo-begin-label context combo-layout label 400)
              (let* ((month (vector-ref selected-date 4))
                     (months #("January" "February" "March" "April" "May" "June" "July" "August" "September" "October" "November" "December"))
                     (month-label (vector-ref months month))
                     (week-days #("SUN" "MON" "TUE" "WED" "THU" "FRI" "SAT"))
                     (month-days #(31 28 31 30 31 30 31 31 30 31 30 31))
                     (year (+ (vector-ref selected-date 5) 1900))
                     (leap-year? (or (and (zero? (modulo year 4))
                                          (not (zero? (modulo year 100))))
                                     (zero? (modulo year 400))))
                     (days (vector-ref month-days month))
                     (days (if (and (= month 1) leap-year?)
                               (add1 days)
                               days)))

                (set! date-selected? #t)
                (nk:layout-row-begin context #t 20 3)
                (nk:layout-row-push context 0.05)
                (when (nk:button-symbol context 'triangle-left)
                  (if (zero? month)
                      (begin
                        (vector-set! selected-date 4 11)
                        (vector-set! selected-date 5 (max 0 (sub1 (vector-ref selected-date 5)))))
                      (vector-set! selected-date 4 (sub1 month))))
                (nk:layout-row-push context 0.9)
                (nk:label context (format "~a ~a" month-label year) 'centered)
                (nk:layout-row-push context 0.05)
                (when (nk:button-symbol context 'triangle-right)
                  (if (= month 11)
                      (begin
                        (vector-set! selected-date 4 0)
                        (vector-set! selected-date 5 (add1 (vector-ref selected-date 5))))
                      (vector-set! selected-date 4 (add1 month))))
                (nk:layout-row-end context)

                (let* ((year-n (if (< month 2) (sub1 year) year))
                       (y (modulo year-n 100))
                       (c (quotient year-n 100))
                       (y4 (floor (/ y 4)))
                       (c4 (floor (/ c 4)))
                       (m (floor (- (* 2.6 (add1 (modulo (+ month 10) 12))) 0.2)))
                       (week-day (modulo (+ (modulo (- (+ 1 m y y4 c4) (* 2 c)) 7) 7) 7)))

                  (nk:layout-row-dynamic context 35 7)
                  (vector-for-each
                   (lambda (_i x)
                     (nk:label context x 'centered))
                   week-days)

                  (when (> week-day 0)
                    (nk:spacing context (inexact->exact week-day)))
                  (let loop ((i 1))
                    (when (<= i days)
                      (when (nk:button-label context (number->string i))
                        (vector-set! selected-date 3 i)
                        (nk:combo-close context))
                      (loop (add1 i))))))
              (nk:combo-end context)))

          (nk:tree-pop context))

        (when (nk:tree-push context #f "Input" #f)
          (nk:layout-row context #f 25 '(120 150))
          (nk:label context "Default:" 'left)

          (vector-set! text 0 (nk:edit-string context 'simple (vector-ref text 0) 64))
          (nk:label context "Int:" 'left)
          (vector-set! text 1 (nk:edit-string context 'simple (vector-ref text 1) 64 'decimal))
          (nk:label context "Float:" 'left)
          (vector-set! text 2 (nk:edit-string context 'simple (vector-ref text 2) 64 'float))
          (nk:label context "Hex:" 'left)
          (vector-set! text 3 (nk:edit-string context 'simple (vector-ref text 3) 64 'hex))
          (nk:label context "Octal:" 'left)
          (vector-set! text 4 (nk:edit-string context 'simple (vector-ref text 4) 64 'oct))
          (nk:label context "Binary:" 'left)
          (vector-set! text 5 (nk:edit-string context 'simple (vector-ref text 5) 64 'binary))

          (nk:label context "Password:" 'left)
          (let* ((password (vector-ref text 6))
                 (buffer (mask-text password))
                 (old-length (string-length buffer))
                 (buffer (nk:edit-string context 'field buffer 64))
                 (new-length (string-length buffer)))
            (cond
             ((> new-length old-length)
              (vector-set! text 6 (string-append password (substring buffer old-length new-length))))
             ((< new-length old-length)
              (vector-set! text 6 (substring password 0 new-length)))))

          (nk:label context "Field:" 'left)
          (set! field-buffer (nk:edit-string context 'field field-buffer 64))

          (nk:label context "Box:" 'left)
          (nk:layout-row-static context 180 278 1)
          (set! box-buffer (nk:edit-string context 'box box-buffer 512))

          (nk:layout-row context #f 25 '(120 150))
          (receive (value edit-events) (nk:edit-string context '(field sig-enter) (vector-ref text 7) 64 'ascii)
                   (vector-set! text 7 value)
                   (when (or (nk:button-label context "Submit")
                             (memv 'committed edit-events))
                     (set! box-buffer (string-append box-buffer value "\n"))
                     (vector-set! text 7 "")))
          (nk:layout-row-end context)
          (nk:tree-pop context))

        (nk:tree-pop context))

      (when (nk:tree-push context #t "Chart" #f)
        (let ((step (/ (* 2 pi) 32)))
          (nk:layout-row-dynamic context 100 1)
          (let ((id 0)
                (index -1))
            (when (nk:chart-begin context #t 32 -1 1)
              (let loop ((i 0))
                (when (< i 32)
                  (let ((events (nk:chart-push context (cos id))))
                    (when (memv 'hovering events)
                      (set! index (floor i)))
                    (when (memv 'clicked events)
                      (set! line-index (floor i)))
                    (set! id (+ id step)))
                  (loop (add1 i))))
              (nk:chart-end context))

            (when (not (= index -1))
              (let ((value (cos (* index step))))
                (nk:tooltip context (cl-format #f "Value: ~,2f" value))))
            (when (not (= line-index -1))
              (nk:layout-row-dynamic context 20 1)
              (let ((value (cos (* line-index step))))
                (nk:label context (cl-format #f "Selected value: ~,2f" value) 'left))))

          (nk:layout-row-dynamic context 100 1)
          (let ((id 0)
                (index -1))
            (when (nk:chart-begin context #f 32 0 1)
              (let loop ((i 0))
                (when (< i 32)
                  (let ((events (nk:chart-push context (abs (sin id)))))
                    (when (memv 'hovering events)
                      (set! index (floor i)))
                    (when (memv 'clicked events)
                      (set! col-index (floor i)))
                    (set! id (+ id step)))
                  (loop (add1 i))))
              (nk:chart-end context))
            (when (not (= index -1))
              (let ((value (abs (sin (* step index)))))
                (nk:tooltip context (cl-format "Value: ~,2f" value))))
            (when (not (= col-index -1))
              (nk:layout-row-dynamic context 20 1)
              (let ((value (abs (sin (* step col-index)))))
                (nk:label context (cl-format "Selected value: ~,2f" value) 'left))))

          (nk:layout-row-dynamic context 100 1)
          (when (nk:chart-begin context #f 32 0 1)
            (nk:chart-add-slot context #t 32 -1 1)
            (nk:chart-add-slot context #t 32 -1 1)
            (let loop ((i 0)
                       (id 0))
              (when (< i 32)
                (nk:chart-push-slot context (abs (sin id)) 0)
                (nk:chart-push-slot context (cos id) 1)
                (nk:chart-push-slot context (sin id) 2)
                (loop (add1 i) (+ id step)))))
          (nk:chart-end context)

          (nk:layout-row-dynamic context 100 1)
          (when (nk:chart-begin-colored context #t (nk:rgb->color 255 0 0) (nk:rgb->color 150 0 0) 32 0 1)
            (nk:chart-add-slot-colored context #t (nk:rgb->color 0 0 255) (nk:rgb->color 0 0 150) 32 -1 1)
            (nk:chart-add-slot-colored context #t (nk:rgb->color 0 255 0) (nk:rgb->color 0 150 0) 32 -1 1)
            (let loop ((i 0)
                       (id 0))
              (when (< i 32)
                (nk:chart-push-slot context (abs (sin id)) 0)
                (nk:chart-push-slot context (cos id) 1)
                (nk:chart-push-slot context (sin id) 2)
                (loop (add1 i) (+ id step)))))
          (nk:chart-end context))
        (nk:tree-pop context))

      (when (nk:tree-push context #t "Popup" #f)
        (let ((bounds #f))
          (nk:layout-row-static context 30 150 1)
          (set! bounds (nk:widget-bounds context))
          (nk:label context "Right click me for menu" 'left)

          (when (nk:contextual-begin context menu-layout #f (nk:make-vec2 100 300) bounds)
            (nk:layout-row-dynamic context 25 1)
            (set! show-menu? (nk:checkbox-label context "Menu" show-menu?))
            (set! progress (nk:progressbar context progress 100 #t))
            (set! slider (nk:slider-int context 0 slider 16 1))
            (when (nk:contextual-item-label context "About" 'centered)
              (set! show-app-about? #t))
            (set! selected
                  (map
                   (lambda (value)
                     (nk:selectable-label context (if value "Unselect" "Select") 'left value))
                   selected))
            (nk:contextual-end context))

          (nk:layout-row-begin context #f 30 2)
          (nk:layout-row-push context 100)
          (nk:label context "Right Click here:" 'left)
          (nk:layout-row-push context 50)
          (set! bounds (nk:widget-bounds context))
          (nk:button-color context color)
          (nk:layout-row-end context)

          (when (nk:contextual-begin context menu-layout #f (nk:make-vec2 350 60) bounds)
            (nk:layout-row-dynamic context 30 4)
            (nk:color-r-set! color (nk:property-int context "#r:" 0 (nk:color-r color) 255 1 1))
            (nk:color-g-set! color (nk:property-int context "#g:" 0 (nk:color-g color) 255 1 1))
            (nk:color-b-set! color (nk:property-int context "#b:" 0 (nk:color-b color) 255 1 1))
            (nk:color-a-set! color (nk:property-int context "#a:" 0 (nk:color-a color) 255 1 1))
            (nk:contextual-end context))

          (nk:layout-row-begin context #f 30 2)
          (nk:layout-row-push context 100)
          (nk:label context "Popup:" 'left)
          (nk:layout-row-push context 50)
          (when (nk:button-label context "Popup")
            (set! popup-active? #t))
          (nk:layout-row-end context)

          (if popup-active?
              (when (nk:popup-begin context popup-layout #f "Error" 'dynamic
                                    (nk:make-rect 20 100 220 150))
                (nk:layout-row-dynamic context 25 1)
                (nk:label context "A terrible error has occurred" 'left)
                (nk:layout-row-dynamic context 25 2)
                (when (nk:button-label context "OK")
                  (set! popup-active? #f)
                  (nk:popup-close context))
                (when (nk:button-label context "Cancel")
                  (set! popup-active? #f)
                  (nk:popup-close context))
                (nk:popup-end context))
              (set! popup-active? #f))

          (nk:layout-row-static context 30 150 1)
          (set! bounds (nk:widget-bounds context))
          (nk:label context "Hover me for tooltip" 'left)
          (when (nk:input-mouse-hovering-in-rect? (nk:context-input context) bounds)
            (nk:tooltip context "This is a tooltip")))
        (nk:tree-pop context))

      (when (nk:tree-push context #t "Layout" #f)
        (when (nk:tree-push context #f "Widget" #f)
          (nk:layout-row-dynamic context 30 1)
          (nk:label context "Dynamic fixed column layout with generated position and size:" 'left)
          (nk:layout-row-dynamic context 30 3)
          (nk:button-label context "button")
          (nk:button-label context "button")
          (nk:button-label context "button")

          (nk:layout-row-dynamic context 30 1)
          (nk:label context "static fixed column layout with generated position and size:" 'left)
          (nk:layout-row-static context 30 100 3)
          (nk:button-label context "button")
          (nk:button-label context "button")
          (nk:button-label context "button")

          (nk:layout-row-dynamic context 30 1)
          (nk:label context "Dynamic list-based custom column layout with generated position and custom size:" 'left)
          (nk:layout-row context #t 30 '(0.2 0.6 0.2))
          (nk:button-label context "button")
          (nk:button-label context "button")
          (nk:button-label context "button")

          (nk:layout-row-dynamic context 30 1)
          (nk:label context "Static list-based custom column layout with generated position and custom size:" 'left)
          (nk:layout-row context #f 30 '(100 200 50))
          (nk:button-label context "button")
          (nk:button-label context "button")
          (nk:button-label context "button")

          (nk:layout-row-dynamic context 30 1)
          (nk:label context "Dynamic immediate mode custom column layout with generated position and custom size:" 'left)
          (nk:layout-row-begin context #t 30 3)
          (nk:layout-row-push context 0.2)
          (nk:button-label context "button")
          (nk:layout-row-push context 0.6)
          (nk:button-label context "button")
          (nk:layout-row-push context 0.2)
          (nk:button-label context "button")
          (nk:layout-row-end context)

          (nk:layout-row-dynamic context 30 1)
          (nk:label context "Static immediate mode custom column layout with generated position and custom size:" 'left)
          (nk:layout-row-begin context #f 30 3)
          (nk:layout-row-push context 100)
          (nk:button-label context "button")
          (nk:layout-row-push context 200)
          (nk:button-label context "button")
          (nk:layout-row-push context 50)
          (nk:button-label context "button")
          (nk:layout-row-end context)

          (nk:layout-row-dynamic context 30 1)
          (nk:label context "Static free space with custom position and custom size:" 'left)
          (nk:layout-space-begin context #f 120 4)
          (nk:layout-space-push context (nk:make-rect 100 0 100 30))
          (nk:button-label context "button")
          (nk:layout-space-push context (nk:make-rect 0 15 100 30))
          (nk:button-label context "button")
          (nk:layout-space-push context (nk:make-rect 200 15 100 30))
          (nk:button-label context "button")
          (nk:layout-space-push context (nk:make-rect 100 30 100 30))
          (nk:button-label context "button")
          (nk:layout-space-end context)
          (nk:tree-pop context))

        (when (nk:tree-push context #f "Group" #f)
          (nk:layout-row-dynamic context 30 3)
          (set! group-titlebar? (nk:checkbox-label context "Titlebar" group-titlebar?))
          (set! group-border? (nk:checkbox-label context "Border" group-border?))
          (set! group-no-scrollbar? (nk:checkbox-label context "No Scrollbar" group-no-scrollbar?))

          (nk:layout-row-begin context #f 22 2)
          (nk:layout-row-push context 50)
          (nk:label context "size:" 'left)
          (nk:layout-row-push context 130)
          (set! group-width (nk:property-int context "#Width:" 100 group-width 500 10 1))
          (nk:layout-row-push context 130)
          (set! group-height (nk:property-int context "#Height:" 100 group-height 500 10 1))
          (nk:layout-row-end context)

          (nk:layout-row-static context group-height group-width 2)
          (when (nk:group-begin context tab-layout "Group" (group-flags))
            (nk:layout-row-static context 18 100 1)
            (set! selected-group
                  (map
                   (lambda (value)
                     (nk:selectable-label context (if value "Selected" "Unselected") 'centered value))
                   selected-group))
            (nk:group-end context))
          (nk:tree-pop context))

        (when (nk:tree-push context #f "Simple" #f)
          (nk:layout-row-dynamic context 300 2)
          (when (nk:group-begin context tab-layout "Group_Without_Border" #f)
            (nk:layout-row-static context 18 150 1)
            (let loop ((i 0))
              (when (< i 64)
                (nk:label context (cl-format #f "0x~2,'0x" i) 'left)
                (loop (add1 i))))
            (nk:group-end context))

          (when (nk:group-begin context tab-layout "Group_With_Border" 'border)
            (nk:layout-row-dynamic context 25 2)
            (let loop ((i 0))
              (when (< i 64)
                (let ((x (+ (bitwise-xor (* (modulo i 7) 10) 32)
                            64 (* (modulo i 2) 2))))
                  (nk:button-label context (cl-format #f "~8,'0d" x))
                (loop (add1 i)))))
            (nk:group-end context))
          (nk:tree-pop context))

        (when (nk:tree-push context #f "Complex" #f)
          (nk:layout-space-begin context #f 500 64)
          (nk:layout-space-push context (nk:make-rect 0 0 150 500))
          (when (nk:group-begin context tab-layout "Group_left" 'border)
            (nk:layout-row-static context 18 100 1)
            (set! left-selected-group
                  (map
                   (lambda (value)
                     (nk:selectable-label context (if value "Selected" "Unselected") 'centered value))
                   left-selected-group))
            (nk:group-end context))

          (nk:layout-space-push context (nk:make-rect 160 0 150 240))
          (when (nk:group-begin context tab-layout "Group_top" 'border)
            (nk:layout-row-dynamic context 25 1)
            (nk:button-label context "#FFAA")
            (nk:button-label context "#FFBB")
            (nk:button-label context "#FFCC")
            (nk:button-label context "#FFDD")
            (nk:button-label context "#FFEE")
            (nk:button-label context "#FFFF")
            (nk:group-end context))

          (nk:layout-space-push context (nk:make-rect 160 250 150 250))
          (when (nk:group-begin context tab-layout "Group_bottom" 'border)
            (nk:layout-row-dynamic context 25 1)
            (nk:button-label context "#FFAA")
            (nk:button-label context "#FFBB")
            (nk:button-label context "#FFCC")
            (nk:button-label context "#FFDD")
            (nk:button-label context "#FFEE")
            (nk:button-label context "#FFFF")
            (nk:group-end context))

          (nk:layout-space-push context (nk:make-rect 320 0 150 150))
          (when (nk:group-begin context tab-layout "Group_right_top" 'border)
            (nk:layout-row-static context 18 100 1)
            (set! top-right-selected-group
                  (map
                   (lambda (value)
                     (nk:selectable-label context (if value "Selected" "Unselected") 'centered value))
                   top-right-selected-group))
            (nk:group-end context))

          (nk:layout-space-push context (nk:make-rect 320 160 150 150))
          (when (nk:group-begin context tab-layout "Group_right_center" 'border)
            (nk:layout-row-static context 18 100 1)
            (set! center-right-selected-group
                  (map
                   (lambda (value)
                     (nk:selectable-label context (if value "Selected" "Unselected") 'centered value))
                   center-right-selected-group))
            (nk:group-end context))

          (nk:layout-space-push context (nk:make-rect 320 320 150 150))
          (when (nk:group-begin context tab-layout "Group_right_bottom" 'border)
            (nk:layout-row-static context 18 100 1)
            (set! bottom-right-selected-group
                  (map
                   (lambda (value)
                     (nk:selectable-label context (if value "Selected" "Unselected") 'centered value))
                   bottom-right-selected-group))
            (nk:group-end context))

          (nk:layout-space-end context)
          (nk:tree-pop context))

        (when (nk:tree-push context #f "Splitter" #f)
          (let ((input (nk:context-input context)))
            (nk:layout-row-static context 20 310 1)
            (nk:label context "Use slider and spinner to change tile size" 'left)
            (nk:label context "Drag the space between tiles to change tile ratio" 'left)
            (when (nk:tree-push context #f "Vertical" #f)
              (let ((row-layout (list vertical-a 8 vertical-b 8 vertical-c))
                    (bounds #f))
                (nk:layout-row-static context 30 100 2)
                (nk:label context "left:" 'left)
                (set! vertical-a (nk:slider-float context 10 vertical-a 200 10))

                (nk:label context "middle:" 'left)
                (set! vertical-b (nk:slider-float context 10 vertical-b 200 10))

                (nk:label context "right:" 'left)
                (set! vertical-c (nk:slider-float context 10 vertical-c 200 10))

                (nk:layout-row context #f 200 row-layout)

                (when (nk:group-begin context sub-layout "left" '(border no-scrollbar))
                  (nk:layout-row-dynamic context 25 1)
                  (nk:button-label context "#FFAA")
                  (nk:button-label context "#FFBB")
                  (nk:button-label context "#FFCC")
                  (nk:button-label context "#FFDD")
                  (nk:button-label context "#FFEE")
                  (nk:button-label context "#FFFF")
                  (nk:group-end context))

                (set! bounds (nk:widget-bounds context))
                (nk:spacing context 1)
                (when (and (or (nk:input-mouse-hovering-in-rect? input bounds)
                               (nk:input-mouse-previously-hovering-in-rect? input bounds))
                           (nk:input-mouse-down? input 'left))
                  (let ((delta (nk:mouse-delta (nk:input-mouse input))))
                    (set! vertical-a (+ (car row-layout) (nk:vec2-x delta)))
                    (set! vertical-b (- (list-ref row-layout 2) (nk:vec2-x delta)))))

                (when (nk:group-begin context sub-layout "center" '(border no-scrollbar))
                  (nk:layout-row-dynamic context 25 1)
                  (nk:button-label context "#FFAA")
                  (nk:button-label context "#FFBB")
                  (nk:button-label context "#FFCC")
                  (nk:button-label context "#FFDD")
                  (nk:button-label context "#FFEE")
                  (nk:button-label context "#FFFF")
                  (nk:group-end context))

                (set! bounds (nk:widget-bounds context))
                (nk:spacing context 1)
                (when (and (or (nk:input-mouse-hovering-in-rect? input bounds)
                               (nk:input-mouse-previously-hovering-in-rect? input bounds))
                           (nk:input-mouse-down? input 'left))
                  (let ((delta (nk:vec2-x (nk:mouse-delta (nk:input-mouse input)))))
                    (set! vertical-b (+ (list-ref row-layout 2) delta))
                    (set! vertical-c (- (list-ref row-layout 4) delta))))

                (when (nk:group-begin context sub-layout "right" '(border no-scrollbar))
                  (nk:layout-row-dynamic context 25 1)
                  (nk:button-label context "#FFAA")
                  (nk:button-label context "#FFBB")
                  (nk:button-label context "#FFCC")
                  (nk:button-label context "#FFDD")
                  (nk:button-label context "#FFEE")
                  (nk:button-label context "#FFFF")
                  (nk:group-end context)))
              (nk:tree-pop context))

            (when (nk:tree-push context #f "Horizontal" #f)
              (let ((bounds #f))
                (nk:layout-row-static context 30 100 2)
                (nk:label context "top:" 'left)
                (set! horizontal-a (nk:slider-float context 10 horizontal-a 200 10))

                (nk:label context "middle:" 'left)
                (set! horizontal-b (nk:slider-float context 10 horizontal-b 200 10))

                (nk:label context "bottom:" 'left)
                (set! horizontal-c (nk:slider-float context 10 horizontal-c 200 10))

                (nk:layout-row-dynamic context horizontal-a 1)
                (when (nk:group-begin context sub-layout "top" '(no-scrollbar border))
                  (nk:layout-row-dynamic context 25 3)
                  (nk:button-label context "#FFAA")
                  (nk:button-label context "#FFBB")
                  (nk:button-label context "#FFCC")
                  (nk:button-label context "#FFDD")
                  (nk:button-label context "#FFEE")
                  (nk:button-label context "#FFFF")
                  (nk:group-end context))

                (nk:layout-row-dynamic context 8 1)
                (set! bounds (nk:widget-bounds context))
                (nk:spacing context 1)
                (when (and (or (nk:input-mouse-hovering-in-rect? input bounds)
                               (nk:input-mouse-previously-hovering-in-rect? input bounds))
                           (nk:input-mouse-down? input 'left))
                  (let ((delta (nk:vec2-y (nk:mouse-delta (nk:input-mouse input)))))
                    (set! horizontal-a (+ horizontal-a delta))
                    (set! horizontal-b (- horizontal-b delta))))

                (nk:layout-row-dynamic context horizontal-b 1)
                (when (nk:group-begin context sub-layout "middle" '(no-scrollbar border))
                  (nk:layout-row-dynamic context 25 3)
                  (nk:button-label context "#FFAA")
                  (nk:button-label context "#FFBB")
                  (nk:button-label context "#FFCC")
                  (nk:button-label context "#FFDD")
                  (nk:button-label context "#FFEE")
                  (nk:button-label context "#FFFF")
                  (nk:group-end context))

                (nk:layout-row-dynamic context 8 1)
                (set! bounds (nk:widget-bounds context))
                (when (and (or (nk:input-mouse-hovering-in-rect? input bounds)
                               (nk:input-mouse-previously-hovering-in-rect? input bounds))
                           (nk:input-mouse-down? input 'left))
                  (let ((delta (nk:vec2-y (nk:mouse-delta (nk:input-mouse input)))))
                    (set! horizontal-b (+ horizontal-b delta))
                    (set! horizontal-c (- horizontal-c delta))))

                (nk:layout-row-dynamic context horizontal-c 1)
                (when (nk:group-begin context sub-layout "bottom" '(no-scrollbar border))
                  (nk:layout-row-dynamic context 25 3)
                  (nk:button-label context "#FFAA")
                  (nk:button-label context "#FFBB")
                  (nk:button-label context "#FFCC")
                  (nk:button-label context "#FFDD")
                  (nk:button-label context "#FFEE")
                  (nk:button-label context "#FFFF")
                  (nk:group-end context)))
              (nk:tree-pop context)))
          (nk:tree-pop context))
        (nk:tree-pop context)))
    (nk:window-end context)

    (let-values (((width height) (glfw:get-window-size (glfw:window))))
      (gl:viewport 0 0 width height))
    (gl:clear gl:+color-buffer-bit+)
    (apply gl:clear-color (nk:color->rgba-floats background))
    (backend:render!)
    (glfw:swap-buffers (glfw:window))
    (loop)))

(backend:shutdown!)
(glfw:terminate)