{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE LambdaCase        #-}
{-# LANGUAGE OverloadedStrings #-}

-- | has (perhaps inevitably) morphed into a module that mostly
-- concerns itself with wrangling haskell's string types
module Util where

import           Data.Aeson as Aeson
import           Data.Text  (Text)
import           Data.Text  as T

-- | haskell's many string types are FUN …
showText :: Show a => a -> Text
showText = T.pack . show

-- | a class to address all the string conversions necessary
-- when using Show to much that just uses Text instead
class PrettyPrint a where
  prettyprint :: a -> Text

-- | let's see if this is a good idea or makes type inference bite us
instance PrettyPrint Text where
  prettyprint text = "\"" <> text <> "\""

-- | same as show json, but without the "String" prefix for json strings
instance PrettyPrint Aeson.Value where
  prettyprint = \case
    Aeson.String s -> prettyprint s
    v              -> (T.pack . show) v

-- | here since Unit is sometimes used as dummy type
instance PrettyPrint () where
  prettyprint _ = error "shouldn't pretty-print Unit"

printPretty :: PrettyPrint a => a -> IO ()
printPretty = putStr . T.unpack . prettyprint