FileIO.hs

{-# LANGUAGE OverloadedStrings #-}

-- | Interface layer: concrete file I/O implementation for IOFunc.
-- This module is responsible for raw I/O only: reading bytes from disk and
-- writing bytes to disk.  All domain logic (line-ending detection, normalisation,
-- restoration) belongs to the ProjectedContext layer.
--
-- IOFunc / AppData values are assembled directly in the Boot layer (Unified.hs)
-- without using Data.Default, keeping construction explicit and visible.
module AIAgent.DiffPatch.Unified.Interface.FileIO
  ( read
  , write
  ) where

import Prelude hiding (read)
import qualified Data.ByteString      as BS
import qualified Data.Text            as T
import qualified Data.Text.Encoding   as TE
import Data.Text.Encoding.Error       (lenientDecode)

-- | Read a file in binary mode and decode as UTF-8 (lenient).
-- Returns raw Text with original line endings preserved.
-- Line-ending normalisation is a domain concern and is handled in ProjectedContext.
read :: FilePath -> IO T.Text
read path = do
  bs <- BS.readFile path
  return (TE.decodeUtf8With lenientDecode bs)

-- | Write Text to a file as UTF-8 binary.
-- The caller is responsible for any line-ending conversion before calling this.
write :: FilePath -> T.Text -> IO ()
write path txt =
  BS.writeFile path (TE.encodeUtf8 txt)