module Main where

import Control.Monad (void)
import Control.Applicative ((<$>))
import Data.List (stripPrefix, isInfixOf)
import Data.Maybe (mapMaybe)

import System.Process (rawSystem)
import System.Exit (exitWith)
import Text.Printf (printf)


srcfiles :: [String]
template, testModule, tok, testPrefix :: String

srcfiles   = ["System/Path/Internal.hs","System/Path/Directory.hs","System/Path/IO.hs"]
template   = "TestTemplate.hs"
testModule = "TestModule.hs"
tok        = "<TESTS_GO_HERE>"
testPrefix = "-- >> "

main :: IO ()
main = do
  testLines <-
     mapMaybe (stripPrefix testPrefix) . concatMap lines <$> mapM readFile srcfiles
  (templateHead,_:templateTail) <-
     break (tok `isInfixOf`) . lines <$> readFile template
  let outLines = (\t -> printf "  (%s,\n    %s) :" (show t) t) <$> testLines

  writeFile testModule $ unlines $
     ("{- Do not edit! Created from " ++ template ++ " -}") :
     templateHead ++ outLines ++ templateTail

  let ghc = "ghc"
      args =
        ["-optP-include", "-optPdist/build/autogen/cabal_macros.h",
         "-e", "TestModule.main", testModule]

  void $ printf "Running %d tests...\n" (length testLines)
  exitWith =<< rawSystem ghc args