{-# LANGUAGE DataKinds #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TypeOperators #-}

module Main (main) where

import Codec.Picture
import Criterion.Main
import Data.ByteString (ByteString)
import Data.ByteString qualified as B
import Data.Proxy
import Data.Word (Word8)
import Graphics.Identicon
import Graphics.Identicon.Primitive
import System.Random
import System.Random.TF.Init

main :: IO ()
main =
  defaultMain
    [ bgen 0 0 gen0,
      bgen 4 1 gen1,
      bgen 8 2 gen2,
      bgen 12 3 gen3
    ]

-- | Run an identicon benchmark given its name and rendering function.
bgen ::
  -- | Number of bytes the generator expects
  Int ->
  -- | Number of layers the generator has
  Int ->
  -- | Generator
  (Int -> Int -> ByteString -> Maybe (Image PixelRGB8)) ->
  -- | Benchmark
  Benchmark
bgen bytes layers gen = bgroup groupName (f <$> testSizes)
  where
    groupName = show bytes ++ " bytes/" ++ show layers ++ " layers"
    f n =
      let n' = show n
       in env (getBS bytes) (bench (n' ++ " × " ++ n') . nf (gen n n))

-- | Obtain a random 'ByteString' of specified length.
getBS :: Int -> IO ByteString
getBS n = do
  gen <- initTFGen
  (return . B.pack . take n . randoms) gen

-- | We render a series of rectangular icons in 'bgen', this list contains
-- size of a side of each icon in pixels.
testSizes :: [Int]
testSizes = [16, 32, 64, 128, 256, 512, 1024]

----------------------------------------------------------------------------
-- Identicon generators

type Gen0 = Identicon 0

gen0 :: Int -> Int -> ByteString -> Maybe (Image PixelRGB8)
gen0 = renderIdenticon (Proxy :: Proxy Gen0) Identicon

type Gen1 = Identicon 4 :+ Consumer 4

gen1 :: Int -> Int -> ByteString -> Maybe (Image PixelRGB8)
gen1 = renderIdenticon (Proxy :: Proxy Gen1) i
  where
    i = Identicon :+ stdLayer

type Gen2 = Identicon 8 :+ Consumer 4 :+ Consumer 4

gen2 :: Int -> Int -> ByteString -> Maybe (Image PixelRGB8)
gen2 = renderIdenticon (Proxy :: Proxy Gen2) i
  where
    i = Identicon :+ stdLayer :+ stdLayer

type Gen3 = Identicon 12 :+ Consumer 4 :+ Consumer 4 :+ Consumer 4

gen3 :: Int -> Int -> ByteString -> Maybe (Image PixelRGB8)
gen3 = renderIdenticon (Proxy :: Proxy Gen3) i
  where
    i = Identicon :+ stdLayer :+ stdLayer :+ stdLayer

stdLayer :: Pixel8 -> Pixel8 -> Pixel8 -> Word8 -> Layer
stdLayer r g b n =
  rsym $
    onGrid 4 4 n $
      circle $
        gradientLR (edge . mid) black (PixelRGB8 r g b)