import Criterion.Main

import qualified Data.Text as T

import qualified Data.Text.Lazy as TL

import qualified Data.Text.Lazy.Encoding as TLE

import qualified Data.ByteString as S

import qualified Data.ByteString.Lazy as L

import Data.ByteString.Lazy.Internal (ByteString (..))

import Data.Streaming.Text

calcLen :: (S.ByteString -> DecodeResult)

        -> L.ByteString

        -> Int

calcLen =

    loop 0

  where

    loop total _ Empty = total

    loop total dec (Chunk bs bss) =

        total' `seq` loop total' dec' bss

      where

        DecodeResultSuccess t dec' = dec bs

        total' = total + T.length t

handleEncoding :: ( String

                  , TL.Text -> L.ByteString

                  , L.ByteString -> TL.Text

                  , S.ByteString -> DecodeResult

                  )

               -> Benchmark

handleEncoding (name, encodeLazy, decodeLazy, decodeStream) = bgroup name

    [ bench "lazy" $ whnf (TL.length . decodeLazy) lbs

    , bench "stream" $ whnf (calcLen decodeStream) lbs

    ]

  where

    text = TL.pack $ concat $ replicate 10 ['\27'..'\2003']

    lbs = encodeLazy text

main :: IO ()

main = defaultMain $ map handleEncoding

    [ ("UTF-8", TLE.encodeUtf8, TLE.decodeUtf8, decodeUtf8)

    , ("UTF-8 pure", TLE.encodeUtf8, TLE.decodeUtf8, decodeUtf8Pure)

    , ("UTF-16LE", TLE.encodeUtf16LE, TLE.decodeUtf16LE, decodeUtf16LE)

    , ("UTF-16BE", TLE.encodeUtf16BE, TLE.decodeUtf16BE, decodeUtf16BE)

    , ("UTF-32LE", TLE.encodeUtf32LE, TLE.decodeUtf32LE, decodeUtf32LE)

    , ("UTF-32BE", TLE.encodeUtf32BE, TLE.decodeUtf32BE, decodeUtf32BE)

    ]