    {-# LANGUAGE CPP #-}
    module Distribution.Simple.HaskellSuite where

    import Control.Monad
    #if __GLASGOW_HASKELL__ < 710
    import Control.Applicative
    #endif
    import Data.Maybe
    import Data.Version
    import qualified Data.Map as M (empty)

    import Distribution.Simple.Program
    import Distribution.Simple.Compiler as Compiler
    import Distribution.Simple.Utils
    import Distribution.Simple.BuildPaths
    import Distribution.Verbosity
    import Distribution.Text
    import Distribution.Package
    import Distribution.InstalledPackageInfo hiding (includeDirs)
    import Distribution.Simple.PackageIndex as PackageIndex
    import Distribution.PackageDescription
    import Distribution.Simple.LocalBuildInfo
    import Distribution.System (Platform)
    import Distribution.Compat.Exception
    import Language.Haskell.Extension
    import Distribution.Simple.Program.Builtin
      (haskellSuiteProgram, haskellSuitePkgProgram)

    configure
      :: Verbosity -> Maybe FilePath -> Maybe FilePath
      -> ProgramConfiguration -> IO (Compiler, Maybe Platform, ProgramConfiguration)
    configure verbosity mbHcPath hcPkgPath conf0 = do

      -- We have no idea how a haskell-suite tool is named, so we require at
      -- least some information from the user.
      hcPath <-
        let msg = "You have to provide name or path of a haskell-suite tool (-w PATH)"
        in maybe (die msg) return mbHcPath

      when (isJust hcPkgPath) $
        warn verbosity "--with-hc-pkg option is ignored for haskell-suite"

      (comp, confdCompiler, conf1) <- configureCompiler hcPath conf0

      -- Update our pkg tool. It uses the same executable as the compiler, but
      -- all command start with "pkg"
      (confdPkg, _) <- requireProgram verbosity haskellSuitePkgProgram conf1
      let conf2 =
            updateProgram
              confdPkg
                { programLocation = programLocation confdCompiler
                , programDefaultArgs = ["pkg"]
                }
              conf1

      return (comp, Nothing, conf2)

      where
        configureCompiler hcPath conf0' = do
          let
            haskellSuiteProgram' =
              haskellSuiteProgram
                { programFindLocation = \v _p -> findProgramLocation v hcPath }

          -- NB: cannot call requireProgram right away — it'd think that
          -- the program is already configured and won't reconfigure it again.
          -- Instead, call configureProgram directly first.
          conf1 <- configureProgram verbosity haskellSuiteProgram' conf0'
          (confdCompiler, conf2) <- requireProgram verbosity haskellSuiteProgram' conf1

          extensions <- getExtensions verbosity confdCompiler
          languages  <- getLanguages  verbosity confdCompiler
          (compName, compVersion) <-
            getCompilerVersion verbosity confdCompiler

          let
            comp = Compiler {
              compilerId             = CompilerId (HaskellSuite compName) compVersion,
              compilerAbiTag         = Compiler.NoAbiTag,
              compilerCompat         = [],
              compilerLanguages      = languages,
              compilerExtensions     = extensions,
              compilerProperties     = M.empty
            }

          return (comp, confdCompiler, conf2)

    hstoolVersion :: Verbosity -> FilePath -> IO (Maybe Version)
    hstoolVersion = findProgramVersion "--hspkg-version" id

    numericVersion :: Verbosity -> FilePath -> IO (Maybe Version)
    numericVersion = findProgramVersion "--compiler-version" (last . words)

    getCompilerVersion :: Verbosity -> ConfiguredProgram -> IO (String, Version)
    getCompilerVersion verbosity prog = do
      output <- rawSystemStdout verbosity (programPath prog) ["--compiler-version"]
      let
        parts = words output
        name = concat $ init parts -- there shouldn't be any spaces in the name anyway
        versionStr = last parts
      version <-
        maybe (die "haskell-suite: couldn't determine compiler version") return $
          simpleParse versionStr
      return (name, version)

    getExtensions :: Verbosity -> ConfiguredProgram -> IO [(Extension, Compiler.Flag)]
    getExtensions verbosity prog = do
      extStrs <-
        lines <$>
        rawSystemStdout verbosity (programPath prog) ["--supported-extensions"]
      return
        [ (ext, "-X" ++ display ext) | Just ext <- map simpleParse extStrs ]

    getLanguages :: Verbosity -> ConfiguredProgram -> IO [(Language, Compiler.Flag)]
    getLanguages verbosity prog = do
      langStrs <-
        lines <$>
        rawSystemStdout verbosity (programPath prog) ["--supported-languages"]
      return
        [ (ext, "-G" ++ display ext) | Just ext <- map simpleParse langStrs ]

    -- Other compilers do some kind of a packagedb stack check here. Not sure
    -- if we need something like that as well.
    getInstalledPackages :: Verbosity -> PackageDBStack -> ProgramConfiguration
                         -> IO InstalledPackageIndex
    getInstalledPackages verbosity packagedbs conf =
      liftM (PackageIndex.fromList . concat) $ forM packagedbs $ \packagedb ->
        do str <-
            getDbProgramOutput verbosity haskellSuitePkgProgram conf
                    ["dump", packageDbOpt packagedb]
             `catchExit` \_ -> die $ "pkg dump failed"
           case parsePackages str of
             Right ok -> return ok
             _       -> die "failed to parse output of 'pkg dump'"

      where
        parsePackages str =
          let parsed = map parseInstalledPackageInfo (splitPkgs str)
           in case [ msg | ParseFailed msg <- parsed ] of
                []   -> Right [ pkg | ParseOk _ pkg <- parsed ]
                msgs -> Left msgs

        splitPkgs :: String -> [String]
        splitPkgs = map unlines . splitWith ("---" ==) . lines
          where
            splitWith :: (a -> Bool) -> [a] -> [[a]]
            splitWith p xs = ys : case zs of
                               []   -> []
                               _:ws -> splitWith p ws
              where (ys,zs) = break p xs

    buildLib
      :: Verbosity -> PackageDescription -> LocalBuildInfo
      -> Library -> ComponentLocalBuildInfo -> IO ()
    buildLib verbosity pkg_descr lbi lib clbi = do
      -- In future, there should be a mechanism for the compiler to request any
      -- number of the above parameters (or their parts) — in particular,
      -- pieces of PackageDescription.
      --
      -- For now, we only pass those that we know are used.

      let odir = buildDir lbi
          bi = libBuildInfo lib
          srcDirs = hsSourceDirs bi ++ [odir]
          dbStack = withPackageDB lbi
          language = fromMaybe Haskell98 (defaultLanguage bi)
          conf = withPrograms lbi
          pkgid = packageId pkg_descr

      runDbProgram verbosity haskellSuiteProgram conf $
        [ "compile", "--build-dir", odir ] ++
        concat [ ["-i", d] | d <- srcDirs ] ++
        concat [ ["-I", d] | d <- [autogenModulesDir lbi, odir] ++ includeDirs bi ] ++
        [ packageDbOpt pkgDb | pkgDb <- dbStack ] ++
        [ "--package-name", display pkgid ] ++
        concat [ ["--package-id", display ipkgid ]
               | (ipkgid, _) <- componentPackageDeps clbi ] ++
        ["-G", display language] ++
        concat [ ["-X", display ex] | ex <- usedExtensions bi ] ++
        cppOptions (libBuildInfo lib) ++
        [ display modu | modu <- libModules lib ]

    installLib
      :: Verbosity
      -> LocalBuildInfo
      -> FilePath  -- ^install location
      -> FilePath  -- ^install location for dynamic libraries
      -> FilePath  -- ^Build location
      -> PackageDescription
      -> Library
      -> IO ()
    installLib verbosity lbi targetDir dynlibTargetDir builtDir pkg lib = do
      let conf = withPrograms lbi
      runDbProgram verbosity haskellSuitePkgProgram conf $
        [ "install-library"
        , "--build-dir", builtDir
        , "--target-dir", targetDir
        , "--dynlib-target-dir", dynlibTargetDir
        , "--package-id", display $ packageId pkg
        ] ++ map display (libModules lib)

    registerPackage
      :: Verbosity
      -> InstalledPackageInfo
      -> PackageDescription
      -> LocalBuildInfo
      -> Bool
      -> PackageDBStack
      -> IO ()
    registerPackage verbosity installedPkgInfo _pkg lbi _inplace packageDbs = do
      (hspkg, _) <- requireProgram verbosity haskellSuitePkgProgram (withPrograms lbi)

      runProgramInvocation verbosity $
        (programInvocation hspkg
          ["update", packageDbOpt $ last packageDbs])
          { progInvokeInput = Just $ showInstalledPackageInfo installedPkgInfo }

    initPackageDB :: Verbosity -> ProgramConfiguration -> FilePath -> IO ()
    initPackageDB verbosity conf dbPath =
      runDbProgram verbosity haskellSuitePkgProgram conf
        ["init", dbPath]

    packageDbOpt :: PackageDB -> String
    packageDbOpt GlobalPackageDB        = "--global"
    packageDbOpt UserPackageDB          = "--user"
    packageDbOpt (SpecificPackageDB db) = "--package-db=" ++ db