import sdl2/sdl2 as sdl
import sdl2/sdl2_gpu as gpu
import glew

import os
import nanovg
import perf
import common
import icons

proc events(): bool =
  result = false
  var e: sdl.Event

  while sdl.pollEvent(addr(e)) != 0:

    # Quit requested
    if e.kind.EventType == sdl.EventQuit:
      return true

    # Key pressed
    elif e.kind.EventType == sdl.EventKeyDown:
      # Exit on Escape key press
      if e.key.keysym.sym == sdl.KeycodeEscape:
        return true

proc frameBufferSize*(window: ptr Window): tuple[w, h: int32] =
  var
    fbWidth: cint
    fbHeight: cint

  window.glGetDrawableSize(fbWidth.addr, fbHeight.addr)

  return (fbWidth.int32, fbHeight.int32)

proc size*(window: ptr Window): tuple[w, h: int32] =
  var
    width: cint
    height: cint

  window.getWindowSize(width.addr, height.addr)

  return (width.int32, height.int32)

template generateFbo(width, height: float, code: untyped): gpu.Image =
  let fb = createFrameBuffer(width, height, ImageFlagsGL.NO_DELETE)
  fb.binde()

  glViewPort(0, 0, width.int, height.int)
  glCullFace(GL_BACK)
  glFrontFace(GL_CCW)
  glClearColor(0.3, 0.3, 0.32, 1.0)
  glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT or GL_STENCIL_BUFFER_BIT)
  beginFrame(width, height, 1.0)
  code
  endFrame()
  gpu.resetRendererState()
  echo fb.texture
  let res = gpu.createImageUsingTexture(cast[TextureHandle](fb.texture), false)
  fb.delete()
  res

proc main() =
  let
    fps = newGraph(RenderStyle.FPS, "Frame Time")
    cpuGraph = newGraph(RenderStyle.MS, "CPU Time")

  discard sdl.init(sdl.INIT_EVERYTHING.uint32)
  discard sdl.glSetAttribute(sdl.GL_STENCIL_SIZE, 1)

  when defined(macosx):
    discard sdl.glSetAttribute(sdl.GL_CONTEXT_PROFILE_MASK, sdl.GL_CONTEXT_PROFILE_CORE.cint)
    discard sdl.glSetAttribute(sdl.GL_CONTEXT_FLAGS, sdl.GL_CONTEXT_FORWARD_COMPATIBLE_FLAG.cint)
    discard sdl.glSetAttribute(sdl.GL_CONTEXT_MAJOR_VERSION, 3)
    discard sdl.glSetAttribute(sdl.GL_CONTEXT_MINOR_VERSION, 2)

  var w, h: cint

  let screen = gpu.initRenderer(gpu.RENDERER_OPENGL_3, 640, 480, sdl.WINDOW_ALLOW_HIGHDPI)

  let vg = nanovg.newContext()
  discard sdl.glSetSwapInterval(0)
  vg.loadFont(currentSourceDir()/"resources"/"Roboto-Regular.ttf", "sans")
  vg.loadFont(currentSourceDir()/"resources"/"umeboshi.ttf", "umeboshi")
  vg.loadFont(currentSourceDir()/"resources"/"Roboto-Bold.ttf", "sans-bold")
  vg.loadFont(currentSourceDir()/"resources"/"fa.ttf", "fa")
  vg.loadFont(currentSourceDir()/"resources"/"entypo.ttf", "icons")

  var done = false
  var prevt: float = sdl.getTicks().float/1000.0

  var image = gpu.loadImage(currentSourceDir()/"resources/howl.png")

  let window = sdl.getWindowFromID(screen.context.windowID)

  while not done:
    gpu.clearRGBA(screen, 0, 0, 0, 0xFF)

    # do gpu drawing

    let fbSize = window.frameBufferSize()

    glViewPort(0, 0, fbSize.w, fbSize.h)
    glCullFace(GL_BACK)
    glFrontFace(GL_CCW)
    glClearColor(0.3, 0.3, 0.32, 1.0)
    glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT or GL_STENCIL_BUFFER_BIT)

    gpu.blit(image, nil, screen, 400, 100)

    gpu.flushBlitBuffer()

    withFrame(vg, window):
      vg.setFont("umeboshi")
      vg.text("Some仮名thing is up", 100, 100, 100)
      vg.drawWindow("Title", 50, 50, 300, 400)
      vg.drawLabel("Hello!", 10, 10, 500, 20)
      vg.drawButton(Icon.Trash, "Delete", 100, 200, 160, 28, rgba(128, 16, 8, 255))
      vg.drawButton(Icon.Trash, "Deleter", 100, 250, 160, 28, rgba(12, 130, 80, 255))
      vg.drawButton("Testing", 100, 300, 160, 28)
      vg.drawSearchBox("Search...", 60, 400, 280, 25)

    gpu.resetRendererState()

    vg.render(fps, 5, 5)
    vg.render(cpuGraph, 210, 5)


    gpu.flip(screen)

    let t: float = sdl.getTicks().float/1000.0
    let dt = t - prevt
    prevt = t

    let cpuTime: float = sdl.getTicks().float/1000.0 - t

    fps.update(dt)
    cpuGraph.update(cpuTime)

    done = events()
  gpu.freeImage(image)
  vg.delete()
  gpu.quit()

main()