{-# LANGUAGE NoImplicitPrelude, TypeSynonymInstances, FlexibleInstances  #-}
module IHaskell.Display.Juicypixels 
     ( module IHaskell.Display
     , module Codec.Picture
     ) where

import Codec.Picture
import ClassyPrelude
import IHaskell.Display
import System.Directory
import System.IO.Unsafe

-- instances
instance IHaskellDisplay DynamicImage where display = displayImageAsJpg 
instance IHaskellDisplay (Image Pixel8) where display = displayImageAsJpg . ImageY8
instance IHaskellDisplay (Image Pixel16) where display = displayImageAsJpg . ImageY16	
instance IHaskellDisplay (Image PixelF) where display =  displayImageAsJpg . ImageYF
instance IHaskellDisplay (Image PixelYA8) where display = displayImageAsJpg . ImageYA8
instance IHaskellDisplay (Image PixelYA16) where display = displayImageAsJpg . ImageYA16
instance IHaskellDisplay (Image PixelRGB8) where display = displayImageAsJpg . ImageRGB8
instance IHaskellDisplay (Image PixelRGB16) where display = displayImageAsJpg . ImageRGB16
instance IHaskellDisplay (Image PixelRGBF) where display =  displayImageAsJpg . ImageRGBF
instance IHaskellDisplay (Image PixelRGBA8) where display = displayImageAsJpg . ImageRGBA8
instance IHaskellDisplay (Image PixelRGBA16) where display = displayImageAsJpg . ImageRGBA16	
instance IHaskellDisplay (Image PixelYCbCr8) where display = displayImageAsJpg . ImageYCbCr8
instance IHaskellDisplay (Image PixelCMYK8) where display = displayImageAsJpg . ImageCMYK8 
instance IHaskellDisplay (Image PixelCMYK16) where display = displayImageAsJpg . ImageCMYK16	

-- main rendering function
displayImageAsJpg ::  DynamicImage -> IO Display
displayImageAsJpg renderable = do
  switchToTmpDir

  let filename = ".ihaskell.juicypixels.jpg"
  -- Write the image
  saveJpgImage 95 filename renderable
  -- Convert to base64.
  imgData <- readFile $ fpFromString filename
  return $ Display [jpg (imWidth renderable) (imHeight renderable) $ base64 imgData]

-- The type DynamicImage does not have a function to extract width and height
imWidth :: DynamicImage -> Int
imWidth img  = w
   where (w, h) = imWidthHeight img

imHeight :: DynamicImage -> Int
imHeight img = h
   where (w, h) = imWidthHeight img

-- Helper functions to pattern match on the DynamicImage Constructors
imWidthHeight :: DynamicImage -> (Int, Int)
imWidthHeight (ImageY8 im)	= imWH im
imWidthHeight (ImageY16 im)	= imWH im
imWidthHeight (ImageYF im)	= imWH im
imWidthHeight (ImageYA8 im)	= imWH im
imWidthHeight (ImageYA16 im) = imWH im
imWidthHeight (ImageRGB8 im) = imWH im	
imWidthHeight (ImageRGB16 im) = imWH im	
imWidthHeight (ImageRGBF im) = imWH im	
imWidthHeight (ImageRGBA8 im) = imWH im
imWidthHeight (ImageRGBA16 im) = imWH im
imWidthHeight (ImageYCbCr8 im) = imWH im	
imWidthHeight (ImageCMYK8 im) = imWH im
imWidthHeight (ImageCMYK16 im) = imWH im

imWH :: (Image a) -> (Int, Int)
imWH im = (imageWidth im, imageHeight im)