module Distribution.Simple.GHCJS (
        configure, getInstalledPackages, getPackageDBContents,
        buildLib, buildExe,
        replLib, replExe,
        startInterpreter,
        installLib, installExe,
        libAbiHash,
        hcPkgInfo,
        registerPackage,
        componentGhcOptions,
        getLibDir,
        isDynamic,
        getGlobalPackageDB,
        runCmd
  ) where

import Distribution.Simple.GHC.ImplInfo
import qualified Distribution.Simple.GHC.Internal as Internal
import Distribution.PackageDescription as PD
import Distribution.InstalledPackageInfo
import Distribution.Package
import Distribution.Simple.PackageIndex ( InstalledPackageIndex )
import qualified Distribution.Simple.PackageIndex as PackageIndex
import Distribution.Simple.LocalBuildInfo
import qualified Distribution.Simple.Hpc as Hpc
import Distribution.Simple.BuildPaths
import Distribution.Simple.Utils
import Distribution.Simple.Program
import qualified Distribution.Simple.Program.HcPkg as HcPkg
import qualified Distribution.Simple.Program.Ar    as Ar
import qualified Distribution.Simple.Program.Ld    as Ld
import qualified Distribution.Simple.Program.Strip as Strip
import Distribution.Simple.Program.GHC
import Distribution.Simple.Setup hiding ( Flag )
import qualified Distribution.Simple.Setup as Cabal
import Distribution.Simple.Compiler hiding ( Flag )
import Distribution.Version
import Distribution.System
import Distribution.Verbosity
import Distribution.Utils.NubList
import Distribution.Text
import Language.Haskell.Extension

import Control.Monad            ( unless, when )
import Data.Char                ( isSpace )
import qualified Data.Map as M  ( fromList  )
import Data.Monoid as Mon       ( Monoid(..) )
import System.Directory         ( doesFileExist )
import System.FilePath          ( (</>), (<.>), takeExtension
                                , takeDirectory, replaceExtension )

configure :: Verbosity -> Maybe FilePath -> Maybe FilePath
          -> ProgramConfiguration
          -> IO (Compiler, Maybe Platform, ProgramConfiguration)
configure verbosity hcPath hcPkgPath conf0 = do
  (ghcjsProg, ghcjsVersion, conf1) <-
    requireProgramVersion verbosity ghcjsProgram
      (orLaterVersion (Version [0,1] []))
      (userMaybeSpecifyPath "ghcjs" hcPath conf0)
  Just ghcjsGhcVersion <- findGhcjsGhcVersion verbosity (programPath ghcjsProg)
  let implInfo = ghcjsVersionImplInfo ghcjsVersion ghcjsGhcVersion

  -- This is slightly tricky, we have to configure ghcjs first, then we use the
  -- location of ghcjs to help find ghcjs-pkg in the case that the user did not
  -- specify the location of ghc-pkg directly:
  (ghcjsPkgProg, ghcjsPkgVersion, conf2) <-
    requireProgramVersion verbosity ghcjsPkgProgram {
      programFindLocation = guessGhcjsPkgFromGhcjsPath ghcjsProg
    }
    anyVersion (userMaybeSpecifyPath "ghcjs-pkg" hcPkgPath conf1)

  Just ghcjsPkgGhcjsVersion <- findGhcjsPkgGhcjsVersion
                                  verbosity (programPath ghcjsPkgProg)

  when (ghcjsVersion /= ghcjsPkgGhcjsVersion) $ die $
       "Version mismatch between ghcjs and ghcjs-pkg: "
    ++ programPath ghcjsProg ++ " is version " ++ display ghcjsVersion ++ " "
    ++ programPath ghcjsPkgProg ++ " is version " ++ display ghcjsPkgGhcjsVersion

  when (ghcjsGhcVersion /= ghcjsPkgVersion) $ die $
       "Version mismatch between ghcjs and ghcjs-pkg: "
    ++ programPath ghcjsProg
    ++ " was built with GHC version " ++ display ghcjsGhcVersion ++ " "
    ++ programPath ghcjsPkgProg
    ++ " was built with GHC version " ++ display ghcjsPkgVersion

  -- be sure to use our versions of hsc2hs, c2hs, haddock and ghc
  let hsc2hsProgram' =
        hsc2hsProgram { programFindLocation =
                          guessHsc2hsFromGhcjsPath ghcjsProg }
      c2hsProgram' =
        c2hsProgram { programFindLocation =
                          guessC2hsFromGhcjsPath ghcjsProg }

      haddockProgram' =
        haddockProgram { programFindLocation =
                          guessHaddockFromGhcjsPath ghcjsProg }
      conf3 = addKnownPrograms [ hsc2hsProgram', c2hsProgram', haddockProgram' ] conf2

  languages  <- Internal.getLanguages  verbosity implInfo ghcjsProg
  extensions <- Internal.getExtensions verbosity implInfo ghcjsProg

  ghcInfo <- Internal.getGhcInfo verbosity implInfo ghcjsProg
  let ghcInfoMap = M.fromList ghcInfo

  let comp = Compiler {
        compilerId         = CompilerId GHCJS ghcjsVersion,
        compilerAbiTag     = AbiTag $
          "ghc" ++ intercalate "_" (map show . versionBranch $ ghcjsGhcVersion),
        compilerCompat     = [CompilerId GHC ghcjsGhcVersion],
        compilerLanguages  = languages,
        compilerExtensions = extensions,
        compilerProperties = ghcInfoMap
      }
      compPlatform = Internal.targetPlatform ghcInfo
  -- configure gcc and ld
  let conf4 = if ghcjsNativeToo comp
                     then Internal.configureToolchain implInfo
                            ghcjsProg ghcInfoMap conf3
                     else conf3
  return (comp, compPlatform, conf4)

ghcjsNativeToo :: Compiler -> Bool
ghcjsNativeToo = Internal.ghcLookupProperty "Native Too"

guessGhcjsPkgFromGhcjsPath :: ConfiguredProgram -> Verbosity
                           -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath]))
guessGhcjsPkgFromGhcjsPath = guessToolFromGhcjsPath ghcjsPkgProgram

guessHsc2hsFromGhcjsPath :: ConfiguredProgram -> Verbosity
                         -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath]))
guessHsc2hsFromGhcjsPath = guessToolFromGhcjsPath hsc2hsProgram

guessC2hsFromGhcjsPath :: ConfiguredProgram -> Verbosity
                       -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath]))
guessC2hsFromGhcjsPath = guessToolFromGhcjsPath c2hsProgram

guessHaddockFromGhcjsPath :: ConfiguredProgram -> Verbosity
                          -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath]))
guessHaddockFromGhcjsPath = guessToolFromGhcjsPath haddockProgram

guessToolFromGhcjsPath :: Program -> ConfiguredProgram
                       -> Verbosity -> ProgramSearchPath
                       -> IO (Maybe (FilePath, [FilePath]))
guessToolFromGhcjsPath tool ghcjsProg verbosity searchpath
  = do let toolname          = programName tool
           path              = programPath ghcjsProg
           dir               = takeDirectory path
           versionSuffix     = takeVersionSuffix (dropExeExtension path)
           guessNormal       = dir </> toolname <.> exeExtension
           guessGhcjsVersioned = dir </> (toolname ++ "-ghcjs" ++ versionSuffix)
                                 <.> exeExtension
           guessGhcjs        = dir </> (toolname ++ "-ghcjs")
                               <.> exeExtension
           guessVersioned    = dir </> (toolname ++ versionSuffix) <.> exeExtension
           guesses | null versionSuffix = [guessGhcjs, guessNormal]
                   | otherwise          = [guessGhcjsVersioned,
                                           guessGhcjs,
                                           guessVersioned,
                                           guessNormal]
       info verbosity $ "looking for tool " ++ toolname
         ++ " near compiler in " ++ dir
       exists <- mapM doesFileExist guesses
       case [ file | (file, True) <- zip guesses exists ] of
                   -- If we can't find it near ghc, fall back to the usual
                   -- method.
         []     -> programFindLocation tool verbosity searchpath
         (fp:_) -> do info verbosity $ "found " ++ toolname ++ " in " ++ fp
                      let lookedAt = map fst
                                   . takeWhile (\(_file, exist) -> not exist)
                                   $ zip guesses exists
                      return (Just (fp, lookedAt))

  where takeVersionSuffix :: FilePath -> String
        takeVersionSuffix = reverse . takeWhile (`elem ` "0123456789.-") .
                            reverse

-- | Given a single package DB, return all installed packages.
getPackageDBContents :: Verbosity -> PackageDB -> ProgramConfiguration
                     -> IO InstalledPackageIndex
getPackageDBContents verbosity packagedb conf = do
  pkgss <- getInstalledPackages' verbosity [packagedb] conf
  toPackageIndex verbosity pkgss conf

-- | Given a package DB stack, return all installed packages.
getInstalledPackages :: Verbosity -> PackageDBStack -> ProgramConfiguration
                     -> IO InstalledPackageIndex
getInstalledPackages verbosity packagedbs conf = do
  checkPackageDbEnvVar
  checkPackageDbStack packagedbs
  pkgss <- getInstalledPackages' verbosity packagedbs conf
  index <- toPackageIndex verbosity pkgss conf
  return $! index

toPackageIndex :: Verbosity
               -> [(PackageDB, [InstalledPackageInfo])]
               -> ProgramConfiguration
               -> IO InstalledPackageIndex
toPackageIndex verbosity pkgss conf = do
  -- On Windows, various fields have $topdir/foo rather than full
  -- paths. We need to substitute the right value in so that when
  -- we, for example, call gcc, we have proper paths to give it.
  topDir <- getLibDir' verbosity ghcjsProg
  let indices = [ PackageIndex.fromList (map (Internal.substTopDir topDir) pkgs)
                | (_, pkgs) <- pkgss ]
  return $! (mconcat indices)

  where
    Just ghcjsProg = lookupProgram ghcjsProgram conf

checkPackageDbEnvVar :: IO ()
checkPackageDbEnvVar =
    Internal.checkPackageDbEnvVar "GHCJS" "GHCJS_PACKAGE_PATH"

checkPackageDbStack :: PackageDBStack -> IO ()
checkPackageDbStack (GlobalPackageDB:rest)
  | GlobalPackageDB `notElem` rest = return ()
checkPackageDbStack rest
  | GlobalPackageDB `notElem` rest =
  die $ "With current ghc versions the global package db is always used "
     ++ "and must be listed first. This ghc limitation may be lifted in "
     ++ "future, see http://hackage.haskell.org/trac/ghc/ticket/5977"
checkPackageDbStack _ =
  die $ "If the global package db is specified, it must be "
     ++ "specified first and cannot be specified multiple times"

getInstalledPackages' :: Verbosity -> [PackageDB] -> ProgramConfiguration
                      -> IO [(PackageDB, [InstalledPackageInfo])]
getInstalledPackages' verbosity packagedbs conf =
  sequence
    [ do pkgs <- HcPkg.dump (hcPkgInfo conf) verbosity packagedb
         return (packagedb, pkgs)
    | packagedb <- packagedbs ]

getLibDir :: Verbosity -> LocalBuildInfo -> IO FilePath
getLibDir verbosity lbi =
    (reverse . dropWhile isSpace . reverse) `fmap`
     rawSystemProgramStdoutConf verbosity ghcjsProgram
     (withPrograms lbi) ["--print-libdir"]

getLibDir' :: Verbosity -> ConfiguredProgram -> IO FilePath
getLibDir' verbosity ghcjsProg =
    (reverse . dropWhile isSpace . reverse) `fmap`
     rawSystemProgramStdout verbosity ghcjsProg ["--print-libdir"]

-- | Return the 'FilePath' to the global GHC package database.
getGlobalPackageDB :: Verbosity -> ConfiguredProgram -> IO FilePath
getGlobalPackageDB verbosity ghcjsProg =
    (reverse . dropWhile isSpace . reverse) `fmap`
     rawSystemProgramStdout verbosity ghcjsProg ["--print-global-package-db"]

toJSLibName :: String -> String
toJSLibName lib
  | takeExtension lib `elem` [".dll",".dylib",".so"]
                              = replaceExtension lib "js_so"
  | takeExtension lib == ".a" = replaceExtension lib "js_a"
  | otherwise                 = lib <.> "js_a"

buildLib, replLib :: Verbosity -> Cabal.Flag (Maybe Int) -> PackageDescription
                  -> LocalBuildInfo -> Library -> ComponentLocalBuildInfo
                  -> IO ()
buildLib = buildOrReplLib False
replLib  = buildOrReplLib True

buildOrReplLib :: Bool -> Verbosity  -> Cabal.Flag (Maybe Int)
               -> PackageDescription -> LocalBuildInfo
               -> Library            -> ComponentLocalBuildInfo -> IO ()
buildOrReplLib forRepl verbosity numJobs _pkg_descr lbi lib clbi = do
  let libName = componentUnitId clbi
      libTargetDir = buildDir lbi
      whenVanillaLib forceVanilla =
        when (not forRepl && (forceVanilla || withVanillaLib lbi))
      whenProfLib = when (not forRepl && withProfLib lbi)
      whenSharedLib forceShared =
        when (not forRepl &&  (forceShared || withSharedLib lbi))
      whenGHCiLib = when (not forRepl && withGHCiLib lbi && withVanillaLib lbi)
      ifReplLib = when forRepl
      comp      = compiler lbi
      platform  = hostPlatform lbi
      implInfo  = getImplInfo comp
      nativeToo = ghcjsNativeToo comp

  (ghcjsProg, _) <- requireProgram verbosity ghcjsProgram (withPrograms lbi)
  let runGhcjsProg        = runGHC verbosity ghcjsProg comp platform
      libBi               = libBuildInfo lib
      isGhcjsDynamic      = isDynamic comp
      dynamicTooSupported = supportsDynamicToo comp
      doingTH = EnableExtension TemplateHaskell `elem` allExtensions libBi
      forceVanillaLib = doingTH && not isGhcjsDynamic
      forceSharedLib  = doingTH &&     isGhcjsDynamic
      -- TH always needs default libs, even when building for profiling

  -- Determine if program coverage should be enabled and if so, what
  -- '-hpcdir' should be.
  let isCoverageEnabled = fromFlag $ configCoverage $ configFlags lbi
      -- Component name. Not 'libName' because that has the "HS" prefix
      -- that GHC gives Haskell libraries.
      cname = display $ PD.package $ localPkgDescr lbi
      distPref = fromFlag $ configDistPref $ configFlags lbi
      hpcdir way
        | isCoverageEnabled = toFlag $ Hpc.mixDir distPref way cname
        | otherwise = Mon.mempty

  createDirectoryIfMissingVerbose verbosity True libTargetDir
  -- TODO: do we need to put hs-boot files into place for mutually recursive
  -- modules?
  let cObjs       = map (`replaceExtension` objExtension) (cSources libBi)
      jsSrcs      = jsSources libBi
      baseOpts    = componentGhcOptions verbosity lbi libBi clbi libTargetDir
      linkJsLibOpts = mempty {
                        ghcOptExtra = toNubListR $
                          [ "-link-js-lib"     , getHSLibraryName libName
                          , "-js-lib-outputdir", libTargetDir ] ++
                          concatMap (\x -> ["-js-lib-src",x]) jsSrcs
                      }
      vanillaOptsNoJsLib = baseOpts `mappend` mempty {
                      ghcOptMode         = toFlag GhcModeMake,
                      ghcOptNumJobs      = numJobs,
                      ghcOptInputModules = toNubListR $ libModules lib,
                      ghcOptHPCDir       = hpcdir Hpc.Vanilla
                    }
      vanillaOpts = vanillaOptsNoJsLib `mappend` linkJsLibOpts

      profOpts    = adjustExts "p_hi" "p_o" vanillaOpts `mappend` mempty {
                        ghcOptProfilingMode = toFlag True,
                        ghcOptExtra         = toNubListR $
                                              ghcjsProfOptions libBi,
                        ghcOptHPCDir        = hpcdir Hpc.Prof
                      }
      sharedOpts  = adjustExts "dyn_hi" "dyn_o" vanillaOpts `mappend` mempty {
                        ghcOptDynLinkMode = toFlag GhcDynamicOnly,
                        ghcOptFPic        = toFlag True,
                        ghcOptExtra       = toNubListR $
                                            ghcjsSharedOptions libBi,
                        ghcOptHPCDir      = hpcdir Hpc.Dyn
                      }
      linkerOpts = mempty {
                      ghcOptLinkOptions    = toNubListR $ PD.ldOptions libBi,
                      ghcOptLinkLibs       = toNubListR $ extraLibs libBi,
                      ghcOptLinkLibPath    = toNubListR $ extraLibDirs libBi,
                      ghcOptLinkFrameworks = toNubListR $ PD.frameworks libBi,
                      ghcOptInputFiles     =
                        toNubListR $ [libTargetDir </> x | x <- cObjs] ++ jsSrcs
                   }
      replOpts    = vanillaOptsNoJsLib {
                      ghcOptExtra        = overNubListR
                                           Internal.filterGhciFlags
                                           (ghcOptExtra vanillaOpts),
                      ghcOptNumJobs      = mempty
                    }
                    `mappend` linkerOpts
                    `mappend` mempty {
                      ghcOptMode         = toFlag GhcModeInteractive,
                      ghcOptOptimisation = toFlag GhcNoOptimisation
                    }

      vanillaSharedOpts = vanillaOpts `mappend`
                            mempty {
                              ghcOptDynLinkMode  = toFlag GhcStaticAndDynamic,
                              ghcOptDynHiSuffix  = toFlag "dyn_hi",
                              ghcOptDynObjSuffix = toFlag "dyn_o",
                              ghcOptHPCDir       = hpcdir Hpc.Dyn
                            }

  unless (forRepl || (null (libModules lib) && null jsSrcs && null cObjs)) $
    do let vanilla = whenVanillaLib forceVanillaLib (runGhcjsProg vanillaOpts)
           shared  = whenSharedLib  forceSharedLib  (runGhcjsProg sharedOpts)
           useDynToo = dynamicTooSupported &&
                       (forceVanillaLib || withVanillaLib lbi) &&
                       (forceSharedLib  || withSharedLib  lbi) &&
                       null (ghcjsSharedOptions libBi)
       if useDynToo
          then do
              runGhcjsProg vanillaSharedOpts
              case (hpcdir Hpc.Dyn, hpcdir Hpc.Vanilla) of
                (Cabal.Flag dynDir, Cabal.Flag vanillaDir) -> do
                    -- When the vanilla and shared library builds are done
                    -- in one pass, only one set of HPC module interfaces
                    -- are generated. This set should suffice for both
                    -- static and dynamically linked executables. We copy
                    -- the modules interfaces so they are available under
                    -- both ways.
                    copyDirectoryRecursive verbosity dynDir vanillaDir
                _ -> return ()
          else if isGhcjsDynamic
            then do shared;  vanilla
            else do vanilla; shared
       whenProfLib (runGhcjsProg profOpts)

  -- build any C sources
  unless (null (cSources libBi) || not nativeToo) $ do
     info verbosity "Building C Sources..."
     sequence_
       [ do let vanillaCcOpts =
                  (Internal.componentCcGhcOptions verbosity implInfo
                     lbi libBi clbi libTargetDir filename)
                profCcOpts    = vanillaCcOpts `mappend` mempty {
                                  ghcOptProfilingMode = toFlag True,
                                  ghcOptObjSuffix     = toFlag "p_o"
                                }
                sharedCcOpts  = vanillaCcOpts `mappend` mempty {
                                  ghcOptFPic        = toFlag True,
                                  ghcOptDynLinkMode = toFlag GhcDynamicOnly,
                                  ghcOptObjSuffix   = toFlag "dyn_o"
                                }
                odir          = fromFlag (ghcOptObjDir vanillaCcOpts)
            createDirectoryIfMissingVerbose verbosity True odir
            runGhcjsProg vanillaCcOpts
            whenSharedLib forceSharedLib (runGhcjsProg sharedCcOpts)
            whenProfLib (runGhcjsProg profCcOpts)
       | filename <- cSources libBi]

  -- TODO: problem here is we need the .c files built first, so we can load them
  -- with ghci, but .c files can depend on .h files generated by ghc by ffi
  -- exports.
  unless (null (libModules lib)) $
     ifReplLib (runGhcjsProg replOpts)

  -- link:
  when (nativeToo && not forRepl) $ do
    info verbosity "Linking..."
    let cProfObjs   = map (`replaceExtension` ("p_" ++ objExtension))
                      (cSources libBi)
        cSharedObjs = map (`replaceExtension` ("dyn_" ++ objExtension))
                      (cSources libBi)
        cid = compilerId (compiler lbi)
        vanillaLibFilePath = libTargetDir </> mkLibName            libName
        profileLibFilePath = libTargetDir </> mkProfLibName        libName
        sharedLibFilePath  = libTargetDir </> mkSharedLibName cid  libName
        ghciLibFilePath    = libTargetDir </> Internal.mkGHCiLibName libName

    hObjs     <- Internal.getHaskellObjects implInfo lib lbi
                      libTargetDir objExtension True
    hProfObjs <-
      if (withProfLib lbi)
              then Internal.getHaskellObjects implInfo lib lbi
                      libTargetDir ("p_" ++ objExtension) True
              else return []
    hSharedObjs <-
      if (withSharedLib lbi)
              then Internal.getHaskellObjects implInfo lib lbi
                      libTargetDir ("dyn_" ++ objExtension) False
              else return []

    unless (null hObjs && null cObjs) $ do

      let staticObjectFiles =
                 hObjs
              ++ map (libTargetDir </>) cObjs
          profObjectFiles =
                 hProfObjs
              ++ map (libTargetDir </>) cProfObjs
          ghciObjFiles =
                 hObjs
              ++ map (libTargetDir </>) cObjs
          dynamicObjectFiles =
                 hSharedObjs
              ++ map (libTargetDir </>) cSharedObjs
          -- After the relocation lib is created we invoke ghc -shared
          -- with the dependencies spelled out as -package arguments
          -- and ghc invokes the linker with the proper library paths
          ghcSharedLinkArgs =
              mempty {
                ghcOptShared             = toFlag True,
                ghcOptDynLinkMode        = toFlag GhcDynamicOnly,
                ghcOptInputFiles         = toNubListR dynamicObjectFiles,
                ghcOptOutputFile         = toFlag sharedLibFilePath,
                ghcOptExtra              = toNubListR $
                                           ghcjsSharedOptions libBi,
                ghcOptNoAutoLinkPackages = toFlag True,
                ghcOptPackageDBs         = withPackageDB lbi,
                ghcOptPackages           = toNubListR $
                                           Internal.mkGhcOptPackages clbi,
                ghcOptLinkLibs           = toNubListR $ extraLibs libBi,
                ghcOptLinkLibPath        = toNubListR $ extraLibDirs libBi
              }

      whenVanillaLib False $ do
        Ar.createArLibArchive verbosity lbi vanillaLibFilePath staticObjectFiles

      whenProfLib $ do
        Ar.createArLibArchive verbosity lbi profileLibFilePath profObjectFiles

      whenGHCiLib $ do
        (ldProg, _) <- requireProgram verbosity ldProgram (withPrograms lbi)
        Ld.combineObjectFiles verbosity ldProg
          ghciLibFilePath ghciObjFiles

      whenSharedLib False $
        runGhcjsProg ghcSharedLinkArgs

-- | Start a REPL without loading any source files.
startInterpreter :: Verbosity -> ProgramConfiguration -> Compiler -> Platform
                 -> PackageDBStack -> IO ()
startInterpreter verbosity conf comp platform packageDBs = do
  let replOpts = mempty {
        ghcOptMode       = toFlag GhcModeInteractive,
        ghcOptPackageDBs = packageDBs
        }
  checkPackageDbStack packageDBs
  (ghcjsProg, _) <- requireProgram verbosity ghcjsProgram conf
  runGHC verbosity ghcjsProg comp platform replOpts

buildExe, replExe :: Verbosity          -> Cabal.Flag (Maybe Int)
                  -> PackageDescription -> LocalBuildInfo
                  -> Executable         -> ComponentLocalBuildInfo -> IO ()
buildExe = buildOrReplExe False
replExe  = buildOrReplExe True

buildOrReplExe :: Bool -> Verbosity  -> Cabal.Flag (Maybe Int)
               -> PackageDescription -> LocalBuildInfo
               -> Executable         -> ComponentLocalBuildInfo -> IO ()
buildOrReplExe forRepl verbosity numJobs _pkg_descr lbi
  exe@Executable { exeName = exeName', modulePath = modPath } clbi = do

  (ghcjsProg, _) <- requireProgram verbosity ghcjsProgram (withPrograms lbi)
  let comp         = compiler lbi
      platform     = hostPlatform lbi
      implInfo     = getImplInfo comp
      runGhcjsProg = runGHC verbosity ghcjsProg comp platform
      exeBi        = buildInfo exe

  -- exeNameReal, the name that GHC really uses (with .exe on Windows)
  let exeNameReal = exeName' <.>
                    (if takeExtension exeName' /= ('.':exeExtension)
                       then exeExtension
                       else "")

  let targetDir = (buildDir lbi) </> exeName'
  let exeDir    = targetDir </> (exeName' ++ "-tmp")
  createDirectoryIfMissingVerbose verbosity True targetDir
  createDirectoryIfMissingVerbose verbosity True exeDir
  -- TODO: do we need to put hs-boot files into place for mutually recursive
  -- modules?  FIX: what about exeName.hi-boot?

  -- Determine if program coverage should be enabled and if so, what
  -- '-hpcdir' should be.
  let isCoverageEnabled = fromFlag $ configCoverage $ configFlags lbi
      distPref = fromFlag $ configDistPref $ configFlags lbi
      hpcdir way
        | isCoverageEnabled = toFlag $ Hpc.mixDir distPref way exeName'
        | otherwise = mempty

  -- build executables

  srcMainFile         <- findFile (exeDir : hsSourceDirs exeBi) modPath
  let isGhcjsDynamic      = isDynamic comp
      dynamicTooSupported = supportsDynamicToo comp
      buildRunner = case clbi of
                       ExeComponentLocalBuildInfo {} -> False
                       _                             -> True
      isHaskellMain = elem (takeExtension srcMainFile) [".hs", ".lhs"]
      jsSrcs        = jsSources exeBi
      cSrcs         = cSources exeBi ++ [srcMainFile | not isHaskellMain]
      cObjs         = map (`replaceExtension` objExtension) cSrcs
      nativeToo     = ghcjsNativeToo comp
      baseOpts   = (componentGhcOptions verbosity lbi exeBi clbi exeDir)
                    `mappend` mempty {
                      ghcOptMode         = toFlag GhcModeMake,
                      ghcOptInputFiles   = toNubListR $
                        [ srcMainFile | isHaskellMain],
                      ghcOptInputModules = toNubListR $
                        [ m | not isHaskellMain, m <- exeModules exe],
                      ghcOptExtra =
                        if buildRunner then toNubListR ["-build-runner"]
                                       else mempty
                    }
      staticOpts = baseOpts `mappend` mempty {
                      ghcOptDynLinkMode    = toFlag GhcStaticOnly,
                      ghcOptHPCDir         = hpcdir Hpc.Vanilla
                   }
      profOpts   = adjustExts "p_hi" "p_o" baseOpts `mappend` mempty {
                      ghcOptProfilingMode  = toFlag True,
                      ghcOptExtra          = toNubListR $ ghcjsProfOptions exeBi,
                      ghcOptHPCDir         = hpcdir Hpc.Prof
                    }
      dynOpts    = adjustExts "dyn_hi" "dyn_o" baseOpts `mappend` mempty {
                      ghcOptDynLinkMode    = toFlag GhcDynamicOnly,
                      ghcOptExtra          = toNubListR $
                                             ghcjsSharedOptions exeBi,
                      ghcOptHPCDir         = hpcdir Hpc.Dyn
                    }
      dynTooOpts = adjustExts "dyn_hi" "dyn_o" staticOpts `mappend` mempty {
                      ghcOptDynLinkMode    = toFlag GhcStaticAndDynamic,
                      ghcOptHPCDir         = hpcdir Hpc.Dyn
                    }
      linkerOpts = mempty {
                      ghcOptLinkOptions    = toNubListR $ PD.ldOptions exeBi,
                      ghcOptLinkLibs       = toNubListR $ extraLibs exeBi,
                      ghcOptLinkLibPath    = toNubListR $ extraLibDirs exeBi,
                      ghcOptLinkFrameworks = toNubListR $ PD.frameworks exeBi,
                      ghcOptInputFiles     = toNubListR $
                                             [exeDir </> x | x <- cObjs] ++ jsSrcs
                   }
      replOpts   = baseOpts {
                      ghcOptExtra          = overNubListR
                                             Internal.filterGhciFlags
                                             (ghcOptExtra baseOpts)
                   }
                   -- For a normal compile we do separate invocations of ghc for
                   -- compiling as for linking. But for repl we have to do just
                   -- the one invocation, so that one has to include all the
                   -- linker stuff too, like -l flags and any .o files from C
                   -- files etc.
                   `mappend` linkerOpts
                   `mappend` mempty {
                      ghcOptMode           = toFlag GhcModeInteractive,
                      ghcOptOptimisation   = toFlag GhcNoOptimisation
                   }
      commonOpts  | withProfExe lbi = profOpts
                  | withDynExe  lbi = dynOpts
                  | otherwise       = staticOpts
      compileOpts | useDynToo = dynTooOpts
                  | otherwise = commonOpts
      withStaticExe = (not $ withProfExe lbi) && (not $ withDynExe lbi)

      -- For building exe's that use TH with -prof or -dynamic we actually have
      -- to build twice, once without -prof/-dynamic and then again with
      -- -prof/-dynamic. This is because the code that TH needs to run at
      -- compile time needs to be the vanilla ABI so it can be loaded up and run
      -- by the compiler.
      -- With dynamic-by-default GHC the TH object files loaded at compile-time
      -- need to be .dyn_o instead of .o.
      doingTH = EnableExtension TemplateHaskell `elem` allExtensions exeBi
      -- Should we use -dynamic-too instead of compiling twice?
      useDynToo = dynamicTooSupported && isGhcjsDynamic
                  && doingTH && withStaticExe && null (ghcjsSharedOptions exeBi)
      compileTHOpts | isGhcjsDynamic = dynOpts
                    | otherwise      = staticOpts
      compileForTH
        | forRepl      = False
        | useDynToo    = False
        | isGhcjsDynamic = doingTH && (withProfExe lbi || withStaticExe)
        | otherwise      = doingTH && (withProfExe lbi || withDynExe lbi)

      linkOpts = commonOpts `mappend`
                 linkerOpts `mappend` mempty {
                      ghcOptLinkNoHsMain   = toFlag (not isHaskellMain)
                 }

  -- Build static/dynamic object files for TH, if needed.
  when compileForTH $
    runGhcjsProg compileTHOpts { ghcOptNoLink  = toFlag True
                               , ghcOptNumJobs = numJobs }

  unless forRepl $
    runGhcjsProg compileOpts { ghcOptNoLink  = toFlag True
                             , ghcOptNumJobs = numJobs }

  -- build any C sources
  unless (null cSrcs || not nativeToo) $ do
   info verbosity "Building C Sources..."
   sequence_
     [ do let opts = (Internal.componentCcGhcOptions verbosity implInfo lbi exeBi
                         clbi exeDir filename) `mappend` mempty {
                       ghcOptDynLinkMode   = toFlag (if withDynExe lbi
                                                       then GhcDynamicOnly
                                                       else GhcStaticOnly),
                       ghcOptProfilingMode = toFlag (withProfExe lbi)
                     }
              odir = fromFlag (ghcOptObjDir opts)
          createDirectoryIfMissingVerbose verbosity True odir
          runGhcjsProg opts
     | filename <- cSrcs ]

  -- TODO: problem here is we need the .c files built first, so we can load them
  -- with ghci, but .c files can depend on .h files generated by ghc by ffi
  -- exports.
  when forRepl $ runGhcjsProg replOpts

  -- link:
  unless forRepl $ do
    info verbosity "Linking..."
    runGhcjsProg linkOpts { ghcOptOutputFile = toFlag (targetDir </> exeNameReal) }

-- |Install for ghc, .hi, .a and, if --with-ghci given, .o
installLib    :: Verbosity
              -> LocalBuildInfo
              -> FilePath  -- ^install location
              -> FilePath  -- ^install location for dynamic libraries
              -> FilePath  -- ^Build location
              -> PackageDescription
              -> Library
              -> ComponentLocalBuildInfo
              -> IO ()
installLib verbosity lbi targetDir dynlibTargetDir builtDir _pkg lib clbi = do
  whenVanilla $ copyModuleFiles "js_hi"
  whenProf    $ copyModuleFiles "js_p_hi"
  whenShared  $ copyModuleFiles "js_dyn_hi"

  whenVanilla $ installOrdinary builtDir targetDir $ toJSLibName vanillaLibName
  whenProf    $ installOrdinary builtDir targetDir $ toJSLibName profileLibName
  whenShared  $ installShared   builtDir dynlibTargetDir $ toJSLibName sharedLibName

  when (ghcjsNativeToo $ compiler lbi) $ do
    -- copy .hi files over:
    whenVanilla $ copyModuleFiles "hi"
    whenProf    $ copyModuleFiles "p_hi"
    whenShared  $ copyModuleFiles "dyn_hi"

    -- copy the built library files over:
    whenVanilla $ installOrdinaryNative builtDir targetDir       vanillaLibName
    whenProf    $ installOrdinaryNative builtDir targetDir       profileLibName
    whenGHCi    $ installOrdinaryNative builtDir targetDir       ghciLibName
    whenShared  $ installSharedNative   builtDir dynlibTargetDir sharedLibName

  where
    install isShared isJS srcDir dstDir name = do
      let src = srcDir </> name
          dst = dstDir </> name
      createDirectoryIfMissingVerbose verbosity True dstDir

      if isShared
        then installExecutableFile verbosity src dst
        else installOrdinaryFile   verbosity src dst

      when (stripLibs lbi && not isJS) $
        Strip.stripLib verbosity
        (hostPlatform lbi) (withPrograms lbi) dst

    installOrdinary = install False True
    installShared   = install True  True

    installOrdinaryNative = install False False
    installSharedNative   = install True  False

    copyModuleFiles ext =
      findModuleFiles [builtDir] [ext] (libModules lib)
      >>= installOrdinaryFiles verbosity targetDir

    cid = compilerId (compiler lbi)
    libName = componentUnitId clbi
    vanillaLibName = mkLibName              libName
    profileLibName = mkProfLibName          libName
    ghciLibName    = Internal.mkGHCiLibName libName
    sharedLibName  = (mkSharedLibName cid)  libName

    hasLib    = not $ null (libModules lib)
                   && null (cSources (libBuildInfo lib))
    whenVanilla = when (hasLib && withVanillaLib lbi)
    whenProf    = when (hasLib && withProfLib    lbi)
    whenGHCi    = when (hasLib && withGHCiLib    lbi)
    whenShared  = when (hasLib && withSharedLib  lbi)

installExe :: Verbosity
              -> LocalBuildInfo
              -> InstallDirs FilePath -- ^Where to copy the files to
              -> FilePath  -- ^Build location
              -> (FilePath, FilePath)  -- ^Executable (prefix,suffix)
              -> PackageDescription
              -> Executable
              -> IO ()
installExe verbosity lbi installDirs buildPref
           (progprefix, progsuffix) _pkg exe = do
  let binDir = bindir installDirs
  createDirectoryIfMissingVerbose verbosity True binDir
  let exeFileName = exeName exe
      fixedExeBaseName = progprefix ++ exeName exe ++ progsuffix
      installBinary dest = do
        rawSystemProgramConf verbosity ghcjsProgram (withPrograms lbi) $
          [ "--install-executable"
          , buildPref </> exeName exe </> exeFileName
          , "-o", dest
          ] ++
          case (stripExes lbi, lookupProgram stripProgram $ withPrograms lbi) of
           (True, Just strip) -> ["-strip-program", programPath strip]
           _                  -> []
  installBinary (binDir </> fixedExeBaseName)

libAbiHash :: Verbosity -> PackageDescription -> LocalBuildInfo
           -> Library -> ComponentLocalBuildInfo -> IO String
libAbiHash verbosity _pkg_descr lbi lib clbi = do
  let
      libBi       = libBuildInfo lib
      comp        = compiler lbi
      platform    = hostPlatform lbi
      vanillaArgs =
        (componentGhcOptions verbosity lbi libBi clbi (buildDir lbi))
        `mappend` mempty {
          ghcOptMode         = toFlag GhcModeAbiHash,
          ghcOptInputModules = toNubListR $ PD.exposedModules lib
        }
      profArgs = adjustExts "js_p_hi" "js_p_o" vanillaArgs `mappend` mempty {
                     ghcOptProfilingMode = toFlag True,
                     ghcOptExtra         = toNubListR (ghcjsProfOptions libBi)
                 }
      ghcArgs = if withVanillaLib lbi then vanillaArgs
           else if withProfLib    lbi then profArgs
           else error "libAbiHash: Can't find an enabled library way"
  --
  (ghcjsProg, _) <- requireProgram verbosity ghcjsProgram (withPrograms lbi)
  hash <- getProgramInvocationOutput verbosity
          (ghcInvocation ghcjsProg comp platform ghcArgs)
  return (takeWhile (not . isSpace) hash)

adjustExts :: String -> String -> GhcOptions -> GhcOptions
adjustExts hiSuf objSuf opts =
  opts `mappend` mempty {
    ghcOptHiSuffix  = toFlag hiSuf,
    ghcOptObjSuffix = toFlag objSuf
  }

registerPackage :: Verbosity
                -> ProgramConfiguration
                -> Bool
                -> PackageDBStack
                -> InstalledPackageInfo
                -> IO ()
registerPackage verbosity progdb multiInstance packageDbs installedPkgInfo
  | multiInstance
  = HcPkg.registerMultiInstance (hcPkgInfo progdb) verbosity
      packageDbs installedPkgInfo

  | otherwise
  = HcPkg.reregister (hcPkgInfo progdb) verbosity
      packageDbs (Right installedPkgInfo)

componentGhcOptions :: Verbosity -> LocalBuildInfo
                    -> BuildInfo -> ComponentLocalBuildInfo -> FilePath
                    -> GhcOptions
componentGhcOptions verbosity lbi bi clbi odir =
  let opts = Internal.componentGhcOptions verbosity lbi bi clbi odir
  in  opts { ghcOptExtra = ghcOptExtra opts `mappend` toNubListR
                             (hcOptions GHCJS bi)
           }

ghcjsProfOptions :: BuildInfo -> [String]
ghcjsProfOptions bi =
  hcProfOptions GHC bi `mappend` hcProfOptions GHCJS bi

ghcjsSharedOptions :: BuildInfo -> [String]
ghcjsSharedOptions bi =
  hcSharedOptions GHC bi `mappend` hcSharedOptions GHCJS bi

isDynamic :: Compiler -> Bool
isDynamic = Internal.ghcLookupProperty "GHC Dynamic"

supportsDynamicToo :: Compiler -> Bool
supportsDynamicToo = Internal.ghcLookupProperty "Support dynamic-too"

findGhcjsGhcVersion :: Verbosity -> FilePath -> IO (Maybe Version)
findGhcjsGhcVersion verbosity pgm =
  findProgramVersion "--numeric-ghc-version" id verbosity pgm

findGhcjsPkgGhcjsVersion :: Verbosity -> FilePath -> IO (Maybe Version)
findGhcjsPkgGhcjsVersion verbosity pgm =
  findProgramVersion "--numeric-ghcjs-version" id verbosity pgm

-- -----------------------------------------------------------------------------
-- Registering

hcPkgInfo :: ProgramConfiguration -> HcPkg.HcPkgInfo
hcPkgInfo conf = HcPkg.HcPkgInfo { HcPkg.hcPkgProgram    = ghcjsPkgProg
                                 , HcPkg.noPkgDbStack    = False
                                 , HcPkg.noVerboseFlag   = False
                                 , HcPkg.flagPackageConf = False
                                 , HcPkg.supportsDirDbs  = True
                                 , HcPkg.requiresDirDbs  = v >= [7,10]
                                 , HcPkg.nativeMultiInstance  = v >= [7,10]
                                 , HcPkg.recacheMultiInstance = True
                                 }
  where
    v                 = versionBranch ver
    Just ghcjsPkgProg = lookupProgram ghcjsPkgProgram conf
    Just ver          = programVersion ghcjsPkgProg

-- | Get the JavaScript file name and command and arguments to run a
--   program compiled by GHCJS
--   the exe should be the base program name without exe extension
runCmd :: ProgramConfiguration -> FilePath
            -> (FilePath, FilePath, [String])
runCmd conf exe =
  ( script
  , programPath ghcjsProg
  , programDefaultArgs ghcjsProg ++ programOverrideArgs ghcjsProg ++ ["--run"]
  )
  where
    script = exe <.> "jsexe" </> "all" <.> "js"
    Just ghcjsProg = lookupProgram ghcjsProgram conf
