Haskell: Find and Replace in File

module MyLib
    ( 
    findReplaceAndCopyFile,
    findReplaceInFile,
    replaceMarkerWithFile,
    replaceMarkerWithFile2,
    replaceMarkerWithFile3

    ) where
    


import Data.List (intercalate)
import Data.List.Split (splitOn)
import System.IO (stdout, hFlush, hPutStr)
import Type.Reflection (typeOf)
import System.Directory

replaceMarkerWithFile_ :: FilePath -> FilePath -> String -> FilePath -> IO ()
replaceMarkerWithFile_ inFile outFile marker injectionFile = do
          inFileText     <- readFile inFile
          injectText <- readFile injectionFile
          let replace from to = intercalate to . splitOn from
              in writeFile outFile (replace marker injectText inFileText)



findReplaceAndCopyFile :: FilePath -> FilePath -> String -> String -> IO ()
findReplaceAndCopyFile f g a b = do
          s     <- readFile f
          let replace from to = intercalate to . splitOn from
              in writeFile g (replace a b s)

deleteAndMoveBack :: FilePath -> FilePath -> IO ()
deleteAndMoveBack a b = do 
  removeFile a
  renameFile b a

findReplaceInFile :: FilePath -> FilePath -> String -> String -> IO ()
findReplaceInFile a b f r = do
  findReplaceAndCopyFile a b f r
  deleteAndMoveBack a b
  
replaceMarkerWithFile :: FilePath -> FilePath -> String -> FilePath -> IO ()
replaceMarkerWithFile a b f r = do
  replaceMarkerWithFile_ a b f r
  deleteAndMoveBack a b

replaceMarkerWithFile2 :: FilePath -> FilePath -> String -> FilePath -> IO ()
replaceMarkerWithFile2 a b f r = do
    replaceMarkerWithFile_ a b f r

replaceMarkerWithFile3_ :: FilePath -> String -> FilePath -> IO ()
replaceMarkerWithFile3_ inFile marker injectionFile = do
          inFileText     <- readFile inFile
          injectText <- readFile injectionFile
          let replace from to = intercalate to . splitOn from
              in putStr (replace marker injectText inFileText)
              
xx :: Bool -> FilePath -> String -> FilePath -> IO ()
xx True a b c = do
  replaceMarkerWithFile3_ a b c
xx False a _ _ = do
  inStr <- readFile a
  putStr inStr
                       
replaceMarkerWithFile3 :: FilePath -> String -> FilePath -> IO ()
replaceMarkerWithFile3 a f r = do
  j <- doesFileExist r
  xx j a f r 

module Main where

import MyLib
import System.Environment

main :: IO ()
main = do
  args <- getArgs
  progName <- getProgName          -- IO String
  runWithArgs progName args
  
runWithArgs "replaceNarmer" args = do
  goReplaceMarkerWithFile args

runWithArgs "replaceNarmer2" args = do
  goReplaceMarkerWithFile2 args

runWithArgs "replaceNarmer3" args = do
  goReplaceMarkerWithFile3 args  
  
runWithArgs "findAndReplace" args = do
  goFindReplaceInFile args
  
runWithArgs x _ = do
  putStrLn ("Unrecognised program name for invocation: " ++ x)

-- |The 'enfile' function takes a string of a filename and returns the desired filename for a new file
enfile :: String -> String
enfile a = a ++ ".tmp"

goReplaceMarkerWithFile3 :: [String] -> IO ()             
goReplaceMarkerWithFile3 [a,f,r] = do
      replaceMarkerWithFile3 a f r
     
goReplaceMarkerWithFile3 _ = do
  putStrLn "Not enough arguments."
  
goReplaceMarkerWithFile2 :: [String] -> IO ()             
goReplaceMarkerWithFile2 [a,b,f,r] = do
      replaceMarkerWithFile2 a b f r

      
goReplaceMarkerWithFile2 _ = do
  putStrLn "Not enough arguments."

goReplaceMarkerWithFile :: [String] -> IO ()             
goReplaceMarkerWithFile [a,b,f,r] = do
      replaceMarkerWithFile a b f r
goReplaceMarkerWithFile [a,f,r] = do
      replaceMarkerWithFile a (enfile a) f r
      
goReplaceMarkerWithFile _ = do
  putStrLn "Not enough arguments."
  
  
  

goFindReplaceInFile :: [String] -> IO ()             
goFindReplaceInFile [a,b,f,r] = do
      findReplaceAndCopyFile a b f r
goFindReplaceInFile [a,f,r] = do
      findReplaceAndCopyFile a (enfile a) f r
      
goFindReplaceInFile _ = do
  putStrLn "Not enough arguments."