-- | Contains the central drawing functions for the dodge loop.
module Dodge.Render (
    doDrawing,
    getWindowSize,
) where

import Control.Lens
import Control.Monad
import qualified Control.Monad.Parallel as MP
--import Data.List (sortOn)
import qualified Data.Map.Strict as M
import Data.Preload.Render
import qualified Data.Vector as V
import qualified Data.Vector.Unboxed.Mutable as UMV
import Dodge.Data.Universe
import Dodge.Render.Lights
import Dodge.Render.ShapePicture
import Dodge.Render.Walls
import Dodge.Shadows
import Dodge.WindowSize
import Foreign
import GLHelp
import Geometry
import Graphics.GL.Core45
import MatrixHelper
import Render
import qualified SDL
import Shader.Bind
import Shader.Data
import Shader.Poke
import Shader.Poke.Cloud

doDrawing :: SDL.Window -> Universe -> IO ()
doDrawing window u
    | SDL.ScancodeY `M.member` (u ^. uvWorld . input . pressedKeys) = doTestDrawing rdata u
    | otherwise = doDrawing' window rdata u
  where
    rdata = u ^. preloadData . renderData

doTestDrawing :: RenderData -> Universe -> IO ()
doTestDrawing _ _ = do
    return ()

doDrawing' :: SDL.Window -> RenderData -> Universe -> IO ()
doDrawing' win pdata u = do
    --sTicks <- SDL.ticks
--    SDL.glSwapWindow win
    let w = _uvWorld u
        cfig = _uvConfig u
        (windowPoints, wallSPics, wallsToPoke) = wallsToDraw w
        lightPoints = lightsToRender cfig (w ^. wCam) (w ^. cWorld . lWorld)
        shadV = _pictureShaders pdata
        nFls = w ^. cWorld . numberFloorVerxs
        nchs = w ^. cWorld . numberChasmVerxs
    -- bind as much data into vbos as feasible at this point
    -- count mutable vectors setup
    pokeCounts <- UMV.replicate (numLayers * numShads) 0
    -- attempt to poke in parallel
    let wswp = wallSPics <> worldSPic cfig u
        ws = wswp ^. _1
        wp = wswp ^. _2
    ((nWins, trueNWalls), (nShapeVs, nIndices, nSilIndices)) <-
        MP.liftM3
            (\_ a b -> (a, b))
            ( pokeLayVerxs shadV pokeCounts wp)
            ( pokeWallsWindows
                (pdata ^. winVBO . vboPtr)
                (pdata ^. wallVBO . vboPtr)
                windowPoints
                wallsToPoke
            )
            ( pokeShape
                (drawShadowsByImportance $ cfig ^. gr_shadow_size)
                (_vboPtr $ _vboShapes pdata)
                (_uiboPtr $ _shapeEBO pdata)
                (_uiboPtr $ _silhouetteEBO pdata)
                (0, 0, 0)
                ws
            )
    nCloudVs' <- -- foldM (pokeCloud $ pdata ^. cloudVBO . vboPtr) 0 (w ^. cWorld . lWorld . clouds)
        V.foldM'
            (pokeCloud (pdata ^. cloudVBO . vboPtr))
            0
            (V.fromList $ w ^. cWorld . lWorld . clouds)
    nCloudVs <-
        V.foldM'
            (pokeDust (pdata ^. cloudVBO . vboPtr))
            nCloudVs'
            (V.fromList $ w ^. cWorld . lWorld . dusts)
    -- bind wall points, silhouette data, surface geometry
    bufferShaderLayers pokeCounts shadV
    bufferPokedVBO (_vboShapes pdata) nShapeVs
    bufferPokedVBO (pdata ^. winVBO) nWins
    bufferPokedVBO (pdata ^. wallVBO) trueNWalls
    bufferPokedVBO (pdata ^. cloudVBO) nCloudVs
    bufferEBO (_shapeEBO pdata) nIndices
    bufferEBO (pdata ^. silhouetteEBO) nSilIndices
    -- set the coordinate uniform ready for drawing elements using world coordinates
    bufferPerspectiveMatrixUBO cfig (w ^. wCam) (pdata ^. matUBO)
    setViewport _gr_world_res cfig
    glBindFramebuffer GL_FRAMEBUFFER (pdata ^. fboBase . _1 . unFBO)
    glDepthMask GL_TRUE
    glDisable GL_BLEND
    glDepthFunc GL_LESS
    -- clear depth and stencil buffers
    glStencilMask 255 -- to alter the entire stencil
    glClearNamedFramebufferfi (pdata ^. fboBase . _1 . unFBO) GL_DEPTH_STENCIL 0 1 0
    -- draw wall occlusions from the camera's point of view
    glStencilFunc GL_NOTEQUAL 128 255
    glStencilOp GL_KEEP GL_KEEP GL_REPLACE
    glEnable GL_CULL_FACE
    unless (debugOn Remove_LOS cfig) $ do
        glUseProgram (pdata ^. ceilingStencilShader)
        glEnable GL_DEPTH_CLAMP
        glDrawArrays GL_TRIANGLES 0 (fromIntegral (trueNWalls * 6))
        glDisable GL_DEPTH_CLAMP
    glStencilMask 127 -- to alter last seven bits
    glStencilOp GL_KEEP GL_KEEP GL_KEEP
    -- clear color and normals
    withArray [0, 0, 0, 1] $
        glClearNamedFramebufferfv (pdata ^. fboBase . _1 . unFBO) GL_COLOR 0
    withArray [0, 0, 0, 0] $
        glClearNamedFramebufferfv (pdata ^. fboBase . _1 . unFBO) GL_COLOR 2
    -- glNamedFramebufferDrawBuffers set in preloadRender
    --draw walls onto base buffer
    glUseProgram (pdata ^. pullWallShader)
    glDrawArrays GL_TRIANGLES 0 (fromIntegral trueNWalls * 6)
    --draw object shapes onto base buffer
    let fs = _shapeShader pdata
    glUseProgram fs
    glDrawArrays GL_TRIANGLES 0 (fromIntegral nIndices)
    -- draw chasm shader blocking floor
    glUseProgram (pdata ^. chasmShader)
    glDepthMask GL_FALSE
    glStencilOp GL_KEEP GL_KEEP GL_INCR
    with 0 $ glClearNamedFramebufferiv (pdata ^. fboBase . _1 . unFBO) GL_STENCIL 0
    -- need to set the drawbuffer to none
    glDrawBuffer GL_NONE
    glDrawArrays GL_TRIANGLES 0 (fromIntegral nchs)
    withArray [GL_COLOR_ATTACHMENT0,GL_COLOR_ATTACHMENT1,GL_COLOR_ATTACHMENT2] $
        glNamedFramebufferDrawBuffers (pdata ^. fboBase . _1 . unFBO) 3
    glDepthMask GL_TRUE
    --draw floor onto base buffer
    glUseProgram (pdata ^. floorShader)
    glStencilFunc GL_EQUAL 0 255
    glDrawArrays GL_TRIANGLES 0 (fromIntegral nFls)
    glEnable GL_BLEND
    --draw lightmap into its own buffer
    createLightMap
        False
        (w ^. wCam)
        cfig
        (cfig ^. gr_shadow_rendering)
        (fromIntegral trueNWalls)
        nSilIndices
        nIndices
        (pdata ^. fboBase . _2 . _2)
        (pdata ^. fboBase . _2 . _3)
        lightPoints
        pdata
--    -- no longer need base positions/normals
--    withArray [GL_COLOR_ATTACHMENT1,GL_COLOR_ATTACHMENT2] $
--        glInvalidateNamedFramebufferData (pdata ^. fboBase . _1 . unFBO) 2
    glColorMask GL_TRUE GL_TRUE GL_TRUE GL_TRUE
    --apply lightmap to base buffer
    glDepthFunc GL_ALWAYS
    glDepthMask GL_FALSE
    glBindFramebuffer GL_FRAMEBUFFER (pdata ^. fboBase . _1 . unFBO)
    glBindTextureUnit 0 (pdata ^. fboLighting . _2 . unTO)
    glEnable GL_BLEND
    glBlendFunc GL_ZERO GL_ONE_MINUS_SRC_COLOR
    glUseProgram (pdata ^. fullscreenShader)
    --glDrawArrays GL_TRIANGLES 0 6
    glDrawArrays GL_TRIANGLES 0 3
    -- no longer need lighting texture
--    with GL_COLOR_ATTACHMENT0 $
--        glInvalidateNamedFramebufferData (pdata ^. fboLighting . _1 . unFBO) 1
    --draw bloom onto bloom buffer
    glBindFramebuffer GL_FRAMEBUFFER (pdata ^. fboBloom . _1 . unFBO)
    withArray [0, 0, 0, 0] $
        glClearNamedFramebufferfv (pdata ^. fboBloom . _1 . unFBO) GL_COLOR 0
    glDepthFunc GL_LEQUAL
    --glBlendFunc GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA
    --glBlendFunc GL_ONE GL_ONE_MINUS_SRC_ALPHA
    glBlendFunc GL_ONE GL_ONE
--    glDepthMask GL_FALSE
--    renderLayer BloomNoZWrite shadV pokeCounts
    glDepthMask GL_TRUE
    renderLayer BloomLayer shadV pokeCounts
    -- draw clouds to block bloom particles, transparency blocks some alpha
    glDepthMask GL_FALSE
    --glBlendColor 0 0 0 0.1 -- using this and GL_CONSTANT_ALPHA below
    glBlendColor 0 0 0 0.05 -- using this and GL_CONSTANT_ALPHA below
    -- can allow for extra bloom to bleed through underneath the clouds
    -- note that BloomNoZWrite will always be under the clouds, this should be
    -- rethought, either do another pass and write just the depth or even remove
    -- the layer entirely
    glBlendFuncSeparate GL_ZERO GL_ONE GL_CONSTANT_ALPHA GL_ONE_MINUS_SRC_ALPHA
    glUseProgram (pdata ^. cloudShader)
    glDrawArrays GL_TRIANGLES 0 (fromIntegral nCloudVs * 6)

    --setup downscale viewport for blurring bloom
    setViewport _gr_downsize_res cfig
    glBindFramebuffer GL_FRAMEBUFFER $ pdata ^. fboHalf . _1 . unFBO
    glDepthFunc GL_ALWAYS
    glGenerateTextureMipmap (pdata ^. fboBloom . _2 . unTO)
    glBindTextureUnit 0 (pdata ^. fboBloom . _2 . unTO)
    glDisable GL_BLEND
    -- this all needs more tuning + more thought
    -- a fade effect would be cool, so not to fully reset last frames bloom
    -- buffers...
    --    withArray [0, 0, 0, 0] $
    --        glClearNamedFramebufferfv (pdata ^. fboHalf1 . _1 . unFBO) GL_COLOR 0
    --    withArray [0, 0, 0, 0] $
    --        glClearNamedFramebufferfv (pdata ^. fboHalf2 . _1 . unFBO) GL_COLOR 0
    --    glBlendFunc GL_ONE GL_ONE_MINUS_SRC_ALPHA
    glUseProgram (_bloomBlurShader pdata)
    --glDrawArrays GL_TRIANGLES 0 6
    glDrawArrays GL_TRIANGLES 0 3
    glBindFramebuffer GL_FRAMEBUFFER $ pdata ^. fboQuarter . _1 . unFBO
    glGenerateTextureMipmap (pdata ^. fboHalf . _2 . unTO)
    glBindTextureUnit 0 (pdata ^. fboHalf . _2 . unTO)
    setViewport (const SixteenthRes) cfig
    glDrawArrays GL_TRIANGLES 0 3
    glEnable GL_BLEND
--    when (cfig ^. gr_bloom) $ do
--        replicateM_ 1 $
--            pingPongBetween
--                (_fboHalf1 pdata)
--                (_fboHalf2 pdata)
--                (_bloomBlurShader pdata)
--        glEnable GL_BLEND
    setViewport _gr_world_res cfig
    --draw clouds onto cloud buffer
    glBindFramebuffer GL_FRAMEBUFFER (pdata ^. fboCloud . _1 . unFBO)
    glDepthFunc GL_LEQUAL
    glDepthMask GL_FALSE
    glBlendFuncSeparatei 0 GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA GL_ONE_MINUS_DST_ALPHA GL_ONE
    --glBlendFunci 0 GL_ONE GL_ONE_MINUS_SRC_ALPHA
    --withArray [GL_COLOR_ATTACHMENT0, GL_NONE] $
    --withArray [GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1] $
    withArray [GL_COLOR_ATTACHMENT0] $
        glNamedFramebufferDrawBuffers (pdata ^. fboCloud . _1 . unFBO) 1
    withArray [0.5, 0.5, 0.5, 0] $
        glClearNamedFramebufferfv
            (pdata ^. fboCloud . _1 . unFBO)
            GL_COLOR
            0
    glUseProgram (pdata ^. cloudShader)
    glDrawArrays GL_TRIANGLES 0 (fromIntegral nCloudVs * 6)
    when (_gr_cloud_shadows cfig) $ do
        ----render transparency depths
        --        glDepthMask GL_TRUE
        glDepthMask GL_TRUE
        glDepthFunc GL_ALWAYS
        withArray [GL_NONE, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2] $
            glNamedFramebufferDrawBuffers (pdata ^. fboCloud . _1 . unFBO) 3
        withArray [0, 0, 0, 0] $
            glClearNamedFramebufferfv (pdata ^. fboCloud . _1 . unFBO) GL_COLOR 1
        withArray [0, 0, 0, 0] $
            glClearNamedFramebufferfv (pdata ^. fboCloud . _1 . unFBO) GL_COLOR 2
        glEnable GL_BLEND
        -- we sum the positions weighted by alpha, and sum the alpha
        glBlendFuncSeparatei 1 GL_SRC_ALPHA GL_ONE GL_ONE GL_ONE
        -- we divide by the alpha later
        -- and sum the normals weighted by alpha
        glBlendFunci 2 GL_SRC_ALPHA GL_ONE
        glUseProgram (pdata ^. cloudShader)
        glDrawArrays GL_TRIANGLES 0 (fromIntegral nCloudVs * 6)
        glBindFramebuffer GL_FRAMEBUFFER (pdata ^. fboPos . _1 . unFBO)
        withArray [0, 0, 0, 0] $ 
            glClearNamedFramebufferfv (pdata ^. fboPos . _1 . unFBO) GL_COLOR 0
        glBindTextureUnit 0 (pdata ^. fboCloud . _2 . _2 . unTO)
        glDepthMask GL_FALSE
        glUseProgram (pdata ^. alphaDivideShader)
        --glDrawArrays GL_TRIANGLES 0 6
        glDrawArrays GL_TRIANGLES 0 3
        ----draw lightmap for cloud buffer
        glDepthMask GL_TRUE
        glDepthFunc GL_LESS
        glEnable GL_BLEND
        glBindFramebuffer GL_FRAMEBUFFER $ pdata ^. fboLighting . _1 . unFBO
        createLightMap
            True
            (w ^. wCam)
            cfig
            (cfig ^. gr_shadows_on_clouds)
            (fromIntegral trueNWalls)
            nSilIndices
            nIndices
            (pdata ^. fboPos . _2)
            (pdata ^. fboCloud . _2 . _3)
            lightPoints
            pdata
        -- no longer need cloud normals
        withArray [GL_COLOR_ATTACHMENT1] $
            glInvalidateNamedFramebufferData (pdata ^. fboCloud . _1 . unFBO) 1
    -- no longer need shape data
    glInvalidateBufferData (pdata ^. vboShapes . vboName)
    --draw windows into window textures
    glBindFramebuffer GL_FRAMEBUFFER (pdata ^. fboWindow . _1 . unFBO)
    glBindTextureUnit 3 (pdata ^. fboPos . _2 . unTO)
    -- glNamedFramebufferDrawBuffers should be set in preloadRender
    withArray [0, 0, 0, 0] $
        glClearNamedFramebufferfv (pdata ^. fboWindow . _1 . unFBO) GL_COLOR 0
    withArray [0, 0, 0, 0] $
        glClearNamedFramebufferfv (pdata ^. fboWindow . _1 . unFBO) GL_COLOR 1
    glEnable GL_CULL_FACE
    glEnable GL_DEPTH_CLAMP
    glDepthFunc GL_LEQUAL
    glDepthMask GL_FALSE
    glEnable GL_BLEND
    --glBlendFunc GL_SRC_ALPHA GL_ONE
    glBindTextureUnit 3 (pdata ^. fboPos . _2 . unTO)
    -- with all source alphas 0.25, alpha -> 0.5
    glBlendFunc GL_ONE_MINUS_DST_ALPHA GL_ONE_MINUS_SRC_ALPHA
    glUseProgram $ pdata ^. windowPullShader
    glDrawArrays GL_TRIANGLES 0 (fromIntegral nWins * 12)
    -- don't need cloud postions any more
    withArray [GL_COLOR_ATTACHMENT0] $
        glInvalidateNamedFramebufferData (pdata ^. fboPos . _1 . unFBO) 1
    glEnable GL_CULL_FACE
    glDisable GL_DEPTH_CLAMP
    --apply lightmap to cloud buffer
    glBindFramebuffer GL_FRAMEBUFFER $ pdata ^. fboCloud . _1 . unFBO
    glDepthMask GL_FALSE
    withArray [GL_COLOR_ATTACHMENT0, GL_NONE] $
        glNamedFramebufferDrawBuffers (pdata ^. fboCloud . _1 . unFBO) 2
    glDepthFunc GL_ALWAYS
    glBindTextureUnit 0 (pdata ^. fboLighting . _2 . unTO)
    glEnable GL_BLEND
    glBlendFuncSeparate GL_ZERO GL_ONE_MINUS_SRC_COLOR GL_ZERO GL_ONE
    glUseProgram (pdata ^. fullscreenShader)
    --glDrawArrays GL_TRIANGLES 0 6
    glDrawArrays GL_TRIANGLES 0 3
    glBlendFunc GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA
    -- bind base buffer for drawing clouds and bloom
    --glBindFramebuffer GL_FRAMEBUFFER (pdata ^. fboBase . _1 . unFBO)
    glBindFramebuffer GL_FRAMEBUFFER (pdata ^. fboFullscreen . _1 . unFBO)
    setViewport (const FullRes) cfig
    glUseProgram (pdata ^. fullscreenShader)
    glBindTextureUnit 0 (pdata ^. fboBase . _2 . _1 . unTO)
    glDisable GL_BLEND
    glDrawArrays GL_TRIANGLES 0 3
    glEnable GL_BLEND
    glBindTextureUnit 0 (pdata ^. fboWindow . _2 . _2 . unTO)
    glBlendFunc GL_DST_COLOR GL_ONE_MINUS_SRC_ALPHA
    --glDrawArrays GL_TRIANGLES 0 6
    glDrawArrays GL_TRIANGLES 0 3
    glBindTextureUnit 0 (pdata ^. fboCloud . _2 . _1 . unTO)
    glUseProgram (pdata ^. upscaleCloudShader)
    glUniform2f 0 (windowXFloat cfig) (windowYFloat cfig)
    glBlendFunc GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA
    glDrawArrays GL_TRIANGLES 0 3
    glUseProgram (pdata ^. fullscreenShader)
    glBindTextureUnit 0 (pdata ^. fboWindow . _2 . _1 . unTO)
    glBlendFunc GL_DST_COLOR GL_ONE_MINUS_SRC_ALPHA
    glDrawArrays GL_TRIANGLES 0 3

    --Draw blurred bloom onto base buffer
    glEnable GL_BLEND
    glBlendFunc GL_SRC_ALPHA GL_ONE
    --glBlendFunc GL_ONE GL_ONE
    glBindTextureUnit 0 (_unTO . snd $ _fboQuarter pdata)
    glUseProgram (pdata ^. fullscreenShader)
    --glDrawArrays GL_TRIANGLES 0 6
    glDrawArrays GL_TRIANGLES 0 3
    glBindTextureUnit 0 (_unTO . snd $ _fboHalf pdata)
    glUseProgram (pdata ^. fullscreenShader)
    --glDrawArrays GL_TRIANGLES 0 6
    glDrawArrays GL_TRIANGLES 0 3
    glBindTextureUnit 0 (_unTO . snd $ _fboBloom pdata)
    glUseProgram (pdata ^. fullscreenShader)
    --glDrawArrays GL_TRIANGLES 0 6
    glDrawArrays GL_TRIANGLES 0 3

    --set viewport for radial distortion
    --setViewportSize (round winx) (round winy)
    setViewport (const FullRes) cfig
    glDepthFunc GL_ALWAYS
    glBlendFunc GL_ONE GL_ZERO
    -- perform distortions
    case getDistortions cfig w of
        [] -> do
--            glBindTextureUnit 0 $ pdata ^. fboBase . _2 . _1 . unTO
            glBindTextureUnit 0 $ pdata ^. fboFullscreen . _2 . unTO
            glBindFramebuffer GL_FRAMEBUFFER 0
            if cfig ^. gr_upscale_filter then do
                glUseProgram (pdata ^. textureAntiaShader)
                glGenerateTextureMipmap (pdata ^. fboBase . _2 . _1 . unTO)
                glUniform2f 0 (windowXFloat cfig) (windowYFloat cfig)
            else glUseProgram (pdata ^. fullscreenShader)
            --glDrawArrays GL_TRIANGLES 0 6
            glDrawArrays GL_TRIANGLES 0 3
        rs' -> do
            let rs = take 15 rs'
            glBindFramebuffer GL_FRAMEBUFFER 0
            withArray (concatMap rdToVec2s rs) $ 
                glNamedBufferSubData (pdata ^. barrelShader . _2 . vboName) 0 
                    (24 * fromIntegral (length rs * sizeOf (0 :: Float)))
--            glBindTextureUnit 1 $ pdata ^. fboBase . _2 . _1 . unTO
            glBindTextureUnit 1 $ pdata ^. fboFullscreen . _2 . unTO
            glUseProgram (pdata ^. barrelShader . _1)
            glUniform1i 0 (fromIntegral (length rs))
            --glDrawArrays GL_TRIANGLES 0 6
            glDrawArrays GL_TRIANGLES 0 6
    glBlendFunc GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA
    -- draw the overlay
    glDepthFunc GL_LEQUAL
    --glDepthFunc GL_ALWAYS
    glDepthMask GL_FALSE
    glEnable GL_BLEND
    --glBlendFunc GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA
    glBlendFunc GL_ONE GL_ONE_MINUS_SRC_ALPHA -- assume premultiplied alpha
    glDisable GL_CULL_FACE
    renderLayer DebugLayer shadV pokeCounts
    withArray (scaleMatrix (2 / windowXFloat cfig) (2 / windowYFloat cfig)) $
        glNamedBufferSubData (pdata ^. matUBO) 0 64
    glDepthMask GL_TRUE
    with 1 $ glClearNamedFramebufferfv 0 GL_DEPTH 0
    renderLayer FixedCoordLayer shadV pokeCounts
    glEnable GL_CULL_FACE
    checkGLError "during doDrawing'"
    SDL.glSwapWindow win

rdToVec2s :: Distortion -> [Point2]
rdToVec2s (RadialDistortion a b c d e f _) = [a,b,c] <> t d <> t e <> t f
  where
    t (V3 x y z) = [x,y,z]

bufferPerspectiveMatrixUBO :: Config -> Camera -> GLuint -> IO ()
bufferPerspectiveMatrixUBO cfig cam uboid =
    withArray
        ( perspectiveMatrixb
            (cam ^. camRot)
            (cam ^. camZoom)
            (cam ^. camCenter)
            (V2 (windowXFloat cfig) (windowYFloat cfig))
            (cam ^. camViewFrom)
        )
        $ glNamedBufferSubData uboid 0 64

getDistortions :: Config -> World -> [Distortion]
getDistortions cfig w
    | cfig ^. gr_distortions = w ^. cWorld . lWorld . distortions
    | otherwise = []

setViewport :: (Config -> ResFactor) -> Config -> IO ()
setViewport f = uncurryV (glViewport 0 0) . getWindowSize f