(local pxl8 (require :pxl8))
(local music (require :mod.music))
(local world-mod (require :pxl8.world))
(local net-mod (require :pxl8.net))

(var paused false)
(var wireframe false)
(var gui nil)
(var render-distance 3)
(var sim-distance 4)
(var current-panel :main)
(var selected-item nil)
(var current-items [])
(var pending-action nil)

(fn init []
  (set gui (pxl8.create_gui))
  (let [w (world-mod.World.get)]
    (when w
      (set render-distance (w:get_render_distance))
      (set sim-distance (w:get_sim_distance)))))

(fn show []
  (set paused true)
  (set current-panel :main)
  (pxl8.set_relative_mouse_mode false)
  (pxl8.center_cursor))

(fn hide []
  (set paused false)
  (pxl8.set_relative_mouse_mode true))

(fn toggle []
  (when (not gui) (init))
  (if paused
      (hide)
      (show)))

(fn select-next []
  (when (> (length current-items) 0)
    (var found-idx nil)
    (for [i 1 (length current-items)]
      (when (= (. current-items i) selected-item)
        (set found-idx i)))
    (if found-idx
        (let [next-idx (+ found-idx 1)]
          (if (<= next-idx (length current-items))
              (set selected-item (. current-items next-idx))
              (set selected-item (. current-items 1))))
        (set selected-item (. current-items 1)))))

(fn select-prev []
  (when (> (length current-items) 0)
    (var found-idx nil)
    (for [i 1 (length current-items)]
      (when (= (. current-items i) selected-item)
        (set found-idx i)))
    (if found-idx
        (let [prev-idx (- found-idx 1)]
          (if (>= prev-idx 1)
              (set selected-item (. current-items prev-idx))
              (set selected-item (. current-items (length current-items)))))
        (set selected-item (. current-items (length current-items))))))

(fn update []
  (set pending-action nil)

  (when gui
    (let [(mx my) (pxl8.get_mouse_pos)]
      (gui:cursor_move mx my))

    (when (pxl8.mouse_pressed 1)
      (gui:cursor_down))

    (when (pxl8.mouse_released 1)
      (gui:cursor_up))

    (when (or (pxl8.key_pressed "down")
              (and (pxl8.key_pressed "tab") (not (pxl8.key_down "lshift")) (not (pxl8.key_down "rshift"))))
      (select-next))

    (when (or (pxl8.key_pressed "up")
              (and (pxl8.key_pressed "tab") (or (pxl8.key_down "lshift") (pxl8.key_down "rshift"))))
      (select-prev))

    (when (or (pxl8.key_pressed "return") (pxl8.key_pressed "space"))
      (when selected-item
        (set pending-action selected-item)))))

(fn menu-button [id x y w h label]
  (table.insert current-items label)
  (when (= selected-item nil)
    (set selected-item label))
  (let [is-selected (= selected-item label)]
    (when is-selected
      (pxl8.rect (- x 3) (- y 3) (+ w 6) (+ h 6) 15))
    (let [clicked (gui:button id x y w h label)]
      (when clicked
        (set selected-item label))
      (or clicked (and is-selected (= pending-action label))))))

(fn draw-main-menu []
  (pxl8.gui_window 200 80 240 235 "pxl8 demo")

  (when (menu-button 1 215 127 210 30 "Resume")
    (hide))

  (let [wire-label (if wireframe "Wireframe: On" "Wireframe: Off")]
    (when (menu-button 4 215 162 210 30 wire-label)
      (set wireframe (not wireframe))))

  (when (menu-button 5 215 197 210 30 "GFX")
    (set current-panel :gfx)
    (set selected-item nil))

  (when (menu-button 6 215 232 210 30 "SFX")
    (set current-panel :sfx)
    (set selected-item nil))

  (when (menu-button 2 215 267 210 30 "Quit")
    (pxl8.quit)))

(fn draw-sfx-panel []
  (pxl8.gui_window 200 100 240 145 "SFX")

  (let [music-label (if (music.is-playing) "Music: On" "Music: Off")]
    (when (menu-button 10 215 147 210 30 music-label)
      (if (music.is-playing)
          (music.stop)
          (music.start))))

  (pxl8.gui_label 215 185 "Volume/Devices: TODO" 15)

  (when (menu-button 20 215 210 210 30 "Back")
    (set current-panel :main)
    (set selected-item nil)))

(fn draw-gfx-panel []
  (pxl8.gui_window 200 100 240 180 "GFX")

  (pxl8.gui_label 215 150 (.. "Render: " render-distance) 15)
  (let [(changed new-val) (gui:slider_int 30 215 165 210 16 render-distance 1 8)]
    (when changed
      (set render-distance new-val)
      (let [w (world-mod.World.get)
            n (net-mod.get)]
        (when w (w:set_render_distance new-val))
        (when n (n:set_chunk_settings new-val sim-distance)))))

  (pxl8.gui_label 215 190 (.. "Sim: " sim-distance) 15)
  (let [(changed new-val) (gui:slider_int 31 215 205 210 16 sim-distance 1 8)]
    (when changed
      (set sim-distance new-val)
      (let [w (world-mod.World.get)
            n (net-mod.get)]
        (when w (w:set_sim_distance new-val))
        (when n (n:set_chunk_settings render-distance new-val)))))

  (when (menu-button 32 215 240 210 30 "Back")
    (set current-panel :main)
    (set selected-item nil)))

(fn draw []
  (set current-items [])
  (when gui
    (gui:begin_frame)

    (case current-panel
      :main (draw-main-menu)
      :sfx (draw-sfx-panel)
      :gfx (draw-gfx-panel))

    (if (gui:is_hovering)
        (pxl8.set_cursor :hand)
        (pxl8.set_cursor :arrow))

    (gui:end_frame)))

{:init init
 :is-paused (fn [] paused)
 :is-wireframe (fn [] wireframe)
 :toggle toggle
 :show show
 :hide hide
 :update update
 :draw draw}