module Metaplug.Eval (eval) where
import Metaplug.Initialize
import System.Directory
import System.FilePath
import Metaplug.Loader
import Metaplug.Types
import Data.Typeable
import System.IO
import GHC

tmpsym = "eval"

eval :: (Typeable a) => String -> FilePath -> IO a
eval str lp = do
  -- setup our file, for starters
  tmpd  <- getTemporaryDirectory
  (f,h) <- openTempFile tmpd "Eval.hs"
  hClose h
  sym   <- initFile f str

  -- get our Dynamic and whatnot
  s <- (initSession lp [] InteractiveMode >>= loadFiles [f])
  e <- compileCall sym s

  -- delete and return
  removeFile f
  return e
      where 
        initFile :: FilePath -> String -> IO String
        initFile f str = do
                let x  = takeBaseName f
                writeFile f  $ "module "++x++" where\n"
                appendFile f $ tmpsym++" = "++str++"\n"
                return $ x++"."++tmpsym