1 files changed, 42 insertions, 17 deletions
diff --git a/Main.hs b/Main.hs
index d52fedc..30f8f0e 100644
--- a/Main.hs
+++ b/Main.hs
@@ -1,10 +1,12 @@
 {-# LANGUAGE LambdaCase #-}
 module Main where
 
+import Control.Monad (forM_, when)
 import Data.Text.Lazy (Text)
 import qualified Data.Text.Lazy as T
+import qualified Data.Text.Lazy.Builder as B
 import qualified Data.Text.Lazy.IO as T
-import System.Environment
+import Options.Applicative
 import System.Exit
 
 import Pattern
@@ -25,24 +27,47 @@ apply' (Pattern name items) origocc@(Occurrence name' args)
 
 travOrigsArgs :: [Origin] -> [(Text, Text)] -> [(Text, Text)]
 travOrigsArgs [] args = args
-travOrigsArgs _ [] = []
 travOrigsArgs (OCopy : items) (arg:args) = arg : travOrigsArgs items args
 travOrigsArgs (ONew name : items) args = (T.pack " ", name) : travOrigsArgs items args
+travOrigsArgs _ [] = []
+
+data Options = Options { optPattern :: Pattern
+                       , optFiles :: [FilePath]
+                       , optInPlace :: Bool }
+  deriving (Show)
+
+parseOptions :: Parser Options
+parseOptions = Options <$> option (eitherReader parsePattern) (short 'p' <> help "The pattern to apply. *-prefixed type variables are added." <> metavar "PAT")
+                       <*> some (argument str (metavar "FILES..."))
+                       <*> switch (short 'i' <> help "Apply changes in-place. WARNING: This mutates files! \
+                                                     \(This also allows multiple files to be given on the command line.)")
 
 main :: IO ()
 main = do
-    getArgs >>= \case
-        [fname, pat] -> do
-            pat' <- case parsePattern pat of
-              Left err -> die err
-              Right pat' -> return pat'
-            source <- readFile fname
-            parsed <- case parseSourceFile fname source pat' of
-              Left err -> die (show err)
-              Right res -> return res
-            print parsed
-            T.putStrLn (pretty parsed)
-            putStrLn (replicate 80 '-')
-            T.putStrLn (pretty (apply pat' parsed))
-        _ -> do
-            die "Usage: refactor-type-parameters <file.hs> <OpenAcc env aenv *taenv t>"
+    opts <- execParser $
+        info (parseOptions <**> helper)
+             (fullDesc
+              <> progDesc "Refactor type variables of a data type in Haskell"
+              <> header "refactor-type-variables - Refactoring Haskell data type parameters")
+
+    when (not (optInPlace opts) && length (optFiles opts) /= 1) $
+        die "Multiple input files can only be given in conjunction with -i"
+
+    forM_ (optFiles opts) $ \fname -> do
+        source <- readFile fname
+        parsed <- case parseSourceFile fname source (optPattern opts) of
+          Left err -> die ("Could not parse '" ++ fname ++ "': " ++ show err)
+          Right res -> return res
+
+        let result = apply (optPattern opts) parsed
+            resultText = B.toLazyText (sourceFileToBuilder False result)
+
+        if optInPlace opts
+            then do T.writeFile fname resultText
+                    putStrLn ("Processed '" ++ fname ++ "'")
+            else T.putStrLn (pretty (apply (optPattern opts) parsed))
+
+        -- print parsed
+        -- T.putStrLn (pretty parsed)
+        -- putStrLn (replicate 80 '-')
+        -- T.putStrLn (pretty (apply (optPattern opts) parsed))