request.hs

#!/usr/bin/env runhaskell

{-# LANGUAGE OverloadedStrings #-}

import Prelude hiding (interact)
import Data.Aeson
import Data.Text (Text)
import Data.Text.Encoding (decodeUtf8)
import qualified Data.Text as T
import qualified Data.Text.IO as TIO
import qualified Data.ByteString.Lazy.Char8 as BSL
import Control.Applicative ((<$>))

data Log = Log { request :: Text } deriving (Show)

instance FromJSON Log where
  parseJSON (Object obj) = Log <$> obj .: "request"

main :: IO ()
main =
  interact
    $ T.unlines
    . (filter dropBlank)
    . (map getRequest)
    . BSL.lines

interact :: (BSL.ByteString -> Text) -> IO ()
interact f = do
  r <- BSL.getContents
  TIO.putStr $ f r

dropBlank :: Text -> Bool
dropBlank x = T.length x > 0

getRequest :: BSL.ByteString -> Text
getRequest x = case eitherDecode x of
  (Right l) -> request l
  (Left err) -> decodeUtf8 . BSL.toStrict $ BSL.intercalate " " ["###", (BSL.pack err), x]