{- | This module exports functions for compiling Elm to JS.
-}
module Elm.Internal.Utils (compile, moduleName, nameAndImports) where

import qualified Data.List as List
import qualified Generate.JavaScript as JS
import qualified Build.Source as Source
import qualified Parse.Module as Parser
import qualified AST.Module as M
import Parse.Parse (dependencies)
import qualified Text.PrettyPrint as P
import qualified Metadata.Prelude as Prelude
import System.IO.Unsafe

-- |This function compiles Elm code to JavaScript. It will return either
--  an error message or the compiled JS code.
compile :: String -> Either String String
compile source =
    case Source.build False interfaces source of
      Left docs -> Left . unlines . List.intersperse "" $ map P.render docs
      Right modul -> Right $ JS.generate modul

{-# NOINLINE interfaces #-}
interfaces :: M.Interfaces
interfaces = unsafePerformIO $ Prelude.interfaces False

-- |This function extracts the module name of a given source program.
moduleName :: String -> Maybe String
moduleName = Parser.getModuleName

-- |This function extracts the module name and imported modules from a given
--  source program.
nameAndImports :: String -> Maybe (String, [String])
nameAndImports src =
    either (const Nothing) Just (dependencies src)