module Render ( setup
              , render
              ) where


import Game
import MainLoop
import Level
import Player
import Tank
import Texture
import Model
import qualified Vector as V

import Control.Monad.State

import Data.Fixed
import Data.Maybe
import Data.Obj3D
import Data.Obj3D.OpenGL
import Data.Ratio
import qualified Data.Map as M

import Bindings.GLPng

import Graphics.Rendering.OpenGL.GL (($=), GLfloat, GLdouble, Capability(..), Vector3(..), Vertex2(..), Vertex4(..))
import Graphics.Rendering.OpenGL.GL.BeginEnd (unsafeRenderPrimitive, PrimitiveMode(..))
import Graphics.Rendering.OpenGL.GL.CoordTrans
import Graphics.Rendering.OpenGL.GL.Colors
import Graphics.Rendering.OpenGL.GL.Framebuffer (clear, ClearBuffer(..))
import Graphics.Rendering.OpenGL.GL.PerFragment (blend, blendFunc, BlendingFactor(..), depthFunc, ComparisonFunction(..))
import Graphics.Rendering.OpenGL.GL.Texturing.Application (texture)
import Graphics.Rendering.OpenGL.GL.Texturing.Objects (textureBinding, TextureObject(..))
import Graphics.Rendering.OpenGL.GL.Texturing.Parameters (Repetition(..), Clamping(..), TextureFilter(..), MinificationFilter, MagnificationFilter)
import Graphics.Rendering.OpenGL.GL.Texturing.Specification (TextureTarget(..))
import Graphics.Rendering.OpenGL.GL.VertexArrays (clientState, ClientArrayType(..))
import Graphics.Rendering.OpenGL.GL.VertexSpec


getTexture :: Texture -> Main TextureObject
getTexture t = do
  ts <- gets textures
  let tobj = M.lookup t ts
  
  if (isJust tobj)
      then
          return $ fromJust tobj
      else do
          path <- liftIO $ texturePath t
          tex <- liftIO $ pngBind path BuildMipmap Alpha (Repeated, Repeat) (Linear', Just Linear') Linear' >>= return . TextureObject . fromIntegral . fst
          modify $ \state -> state {textures = M.insert t tex ts}
          return tex

getModel :: Model -> Main InterleavedObj
getModel m = do
  ms <- gets models
  let mobj = M.lookup m ms
  
  if (isJust mobj)
      then
          return $ fromJust mobj
      else do
          path <- liftIO $ modelPath m
          objmod <- liftIO $ loadObjFile path
          
          model <- case objmod of
                     Left error -> fail $ show error
                     Right obj  -> liftIO $ makeInterleavedArrays obj
          modify $ \state -> state {models = M.insert m model ms}
          return model
                                               

setup :: Main ()
setup = do
  (lw, lh) <- gets (level . gameState) >>= \l -> return (fromIntegral . levelWidth $ l :: GLfloat, fromIntegral . levelHeight $ l :: GLfloat)
  
  liftIO $ do
          blend $= Enabled
          blendFunc $= (SrcAlpha, OneMinusSrcAlpha)
          depthFunc $= Just Lequal
          shadeModel $= Smooth
          lighting $= Enabled
          light (Light 0) $= Enabled
          position (Light 0) $= Vertex4 (-1) (-1) 1.5 (0 :: GLfloat)
          colorMaterial $= Just (Front, AmbientAndDiffuse)
          
          clientState VertexArray $= Enabled
          clientState NormalArray $= Enabled
          clientState TextureCoordArray $= Enabled
           
  
  -- cache textures & models
  getTexture TextureWood
  getTexture TextureTank
  getTexture TextureCannon
  getTexture TextureBullet
  getTexture TextureCrosshair
  
  getModel ModelTank
  getModel ModelBullet
  getModel ModelBlock
  
  return ()


render :: Main ()
render = do
  tanklist <- gets $ tanks . gameState
  bulletlist <- gets $ bullets . gameState
  playerlist <- gets players
  
  textureWood <- getTexture TextureWood
  textureTank <- getTexture TextureTank
  textureCannon <- getTexture TextureCannon
  textureBullet <- getTexture TextureBullet
  textureCrosshair <- getTexture TextureCrosshair
  
  modelTank <- getModel ModelTank
  modelBullet <- getModel ModelBullet
  modelBlock <- getModel ModelBlock
  
  (lw, lh) <- gets (level . gameState) >>= \l -> return (fromIntegral . levelWidth $ l :: GLfloat, fromIntegral . levelHeight $ l :: GLfloat)
  
  liftIO $ do
           clear [ColorBuffer, DepthBuffer]
           
           depthFunc $= Just Lequal
           
           texture Texture2D $= Enabled
           textureBinding Texture2D $= Just textureWood
           
           normal $ Normal3 0 0 (1 :: GLfloat)
           
           unsafeRenderPrimitive Quads $ do
             texCoord $ TexCoord2 (-0.5 :: GLfloat) (-0.5 :: GLfloat)
             vertex $ Vertex2 (-1) (lh+1)
             
             texCoord $ TexCoord2 (lw/2+0.5) (-0.5)
             vertex $ Vertex2 (lw+1) (lh+1)
             
             texCoord $ TexCoord2 (lw/2+0.5) (lh/2+0.5)
             vertex $ Vertex2 (lw+1) (-1)
             
             texCoord $ TexCoord2 (-0.5) (lh/2+0.5)
             vertex $ Vertex2 (-1 :: GLfloat) (-1 :: GLfloat)
           
           bindInterleavedArrays modelTank
           
           forM_ tanklist $ \tank -> unsafePreservingMatrix $ do
                                       let x = realToFrac . tankX $ tank
                                           y = realToFrac . tankY $ tank
                                           rotDir = realToFrac . V.toAngle . tankDir $ tank
                                           rotAim = realToFrac . V.toAngle . tankAim $ tank
                                       
                                       translate $ Vector3 x y (0 :: GLfloat)
                                       rotate (rotDir*180/pi) $ Vector3 0 0 (1 :: GLfloat)
                                       
                                       textureBinding Texture2D $= Just textureTank
                                       
                                       unsafePreservingMatrix $ do
                                                                rotate 90 $ Vector3 1 0 (0 :: GLfloat)
                                                                drawObject modelTank 1
                                       
                                       rotate ((rotAim-rotDir)*180/pi) $ Vector3 0 0 (1 :: GLfloat)
                                       
                                       textureBinding Texture2D $= Just textureCannon
                                       
                                       unsafePreservingMatrix $ do
                                                                rotate 90 $ Vector3 1 0 (0 :: GLfloat)
                                                                drawObject modelTank 0
           
           texture Texture2D $= Disabled
           bindInterleavedArrays modelBullet
                                       
           forM_ bulletlist $ \bullet -> unsafePreservingMatrix $ do
                                           let x = realToFrac . bulletX $ bullet
                                               y = realToFrac . bulletY $ bullet
                                               rotDir = realToFrac . V.toAngle . bulletDir $ bullet
                                       
                                           translate $ Vector3 x y (0.25 :: GLfloat)
                                           rotate ((rotDir*180/pi)-90) $ Vector3 0 0 (1 :: GLfloat)
                                       
                                           unsafePreservingMatrix $ do
                                                                    drawObject modelBullet 0
           
           bindInterleavedArrays modelBlock
           
           texture Texture2D $= Enabled
           textureBinding Texture2D $= Just textureWood
           forM_ [0.5..13.5] $ \x -> unsafePreservingMatrix $ do
             translate $ Vector3 x 8.5 (0.5 :: GLfloat)
             rotate 90 $ Vector3 1 0 (0 :: GLfloat)
             drawObject modelBlock 0
           
           forM_ [0.5..13.5] $ \x -> unsafePreservingMatrix $ do
             translate $ Vector3 x (-0.5) (0.5 :: GLfloat)
             rotate 90 $ Vector3 1 0 (0 :: GLfloat)
             drawObject modelBlock 0
           
           forM_ [-0.5..8.5] $ \y -> unsafePreservingMatrix $ do
             translate $ Vector3 (-0.5) y (0.5 :: GLfloat)
             rotate 90 $ Vector3 1 0 (0 :: GLfloat)
             drawObject modelBlock 0
           
           forM_ [-0.5..8.5] $ \y -> unsafePreservingMatrix $ do
             translate $ Vector3 14.5 y (0.5 :: GLfloat)
             rotate 90 $ Vector3 1 0 (0 :: GLfloat)
             drawObject modelBlock 0
           
           depthFunc $= Just Always
           
           textureBinding Texture2D $= Just textureCrosshair
           forM_ playerlist renderPlayer