{- | see also "Text.Regex.Do.Pcre.Ascii.Replace"

    'Pattern' & 'Body' are wrapped in 'Utf8_' encoding tag.
    This tag adds clarity, prevents calling Ascii functions by mistake.

    __'toByteString''__ converts String to 'Utf8_' 'ByteString'     -}

module Text.Regex.Do.Pcre.Utf8.Replace
    (Replace(..))  where

import Prelude as P
import Text.Regex.Do.Type.Do
import Text.Regex.Do.Pcre.Matchf
import qualified Text.Regex.Do.ReplaceOpen as O
import Text.Regex.Do.Type.Regex as T
import Text.Regex.Do.Type.MatchHint
import Text.Regex.Do.Convert
import Data.ByteString


class Replace all enc a repl where
    replace::all (Pattern (enc a)) -> repl (enc a) -> Body (enc a) -> a


instance Replace Once Utf8_ String Replacement where
    replace = replace_str marray_

instance Replace All Utf8_ String Replacement where
    replace = replace_str marray_

replace_str f0 p0 r0 b0 =
   let ma1 = f0 p1 b1
       b1 = toByteString . val <$> b0
       r1 = toByteString <$> (val <$> r0)
       p1 = T.makeRegex' . (toByteString' . val <$>) <$> p0
   in toString $ O.replace ma1 r1 b1


instance Replace Once Utf8_ ByteString Replacement where
    replace = replace_bs marray_

instance Replace All Utf8_ ByteString Replacement where
    replace = replace_bs marray_

replace_bs f0 p0 r0 b0 =
   let ma1 = f0 p1 b1
       b1 = val <$> b0
       p1 = T.makeRegex' . (Utf8_ . val <$>) <$> p0
   in O.replace ma1 (val <$> r0) b1



instance Replace Once Utf8_ ByteString GroupReplacer where
    replace = replace_bs' marray_

instance Replace All Utf8_ ByteString GroupReplacer where
    replace = replace_bs' marray_

{- ^ >>> replacer::GroupReplacer (Utf8_ ByteString)
         replacer = defaultReplacer 1 tweak1
          where tweak1 bs1 = toByteString' $
                                if bs1 == toByteString' "左" then
                                      "ー右ー"
                                       else "?"


     >>> runFn1 `shouldBe` toByteString "100メートルー右ー折後、左"
            where runFn1 =
                     let rx1 = Pattern $ toByteString' "(?<=ル)(左)"
                         body1 = Body $ toByteString' "100メートル左折後、左"
                     in replace (All rx1) replacer body1        -}


replace_bs' f0 p0 r0 b0 =
   let ma1 = f0 p1 b1
       b1 = val <$> b0
       p1 = T.makeRegex' . (Utf8_ . val <$>) <$> p0
   in O.replace ma1 (val' r0) b1


{- ^ to tweak regex with 'Comp' or 'Exec', see "Text.Regex.Do.Type.Regex"

    note 'Once_Utf8' and 'All_Utf8' hints   -}