    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Distribution.Simple.JHC
    -- Copyright   :  Isaac Jones 2003-2006
    --
    -- Maintainer  :  cabal-devel@haskell.org
    -- Portability :  portable
    --
    -- This module contains most of the JHC-specific code for configuring, building
    -- and installing packages.

    {-
    Copyright (c) 2009, Henning Thielemann
    Copyright (c) 2003-2005, Isaac Jones
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:

        * Redistributions of source code must retain the above copyright
          notice, this list of conditions and the following disclaimer.

        * Redistributions in binary form must reproduce the above
          copyright notice, this list of conditions and the following
          disclaimer in the documentation and/or other materials provided
          with the distribution.

        * Neither the name of Isaac Jones nor the names of other
          contributors may be used to endorse or promote products derived
          from this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -}

    module Distribution.Simple.JHC (
            configure, getInstalledPackages,
            buildLib, buildExe,
            installLib, installExe
     ) where

    import Distribution.PackageDescription as PD
           ( PackageDescription(..), BuildInfo(..), Executable(..)
           , Library(..), libModules, hcOptions, usedExtensions )
    import Distribution.InstalledPackageInfo
             ( emptyInstalledPackageInfo, )
    import qualified Distribution.InstalledPackageInfo as InstalledPackageInfo
    import Distribution.Simple.PackageIndex (PackageIndex)
    import qualified Distribution.Simple.PackageIndex as PackageIndex
    import Distribution.Simple.LocalBuildInfo
             ( LocalBuildInfo(..), ComponentLocalBuildInfo(..) )
    import Distribution.Simple.BuildPaths
                                    ( autogenModulesDir, exeExtension )
    import Distribution.Simple.Compiler
             ( CompilerFlavor(..), CompilerId(..), Compiler(..)
             , PackageDBStack, Flag, languageToFlags, extensionsToFlags )
    import Language.Haskell.Extension
             ( Language(Haskell98), Extension(..))
    import Distribution.Simple.Program
             ( ConfiguredProgram(..), jhcProgram, ProgramConfiguration
             , userMaybeSpecifyPath, requireProgramVersion, lookupProgram
             , rawSystemProgram, rawSystemProgramStdoutConf )
    import Distribution.Version
             ( Version(..), orLaterVersion )
    import Distribution.Package
             ( Package(..), InstalledPackageId(InstalledPackageId),
               pkgName, pkgVersion, )
    import Distribution.Simple.Utils
            ( createDirectoryIfMissingVerbose, writeFileAtomic
            , installOrdinaryFile, installExecutableFile
            , intercalate )
    import System.FilePath          ( (</>) )
    import Distribution.Verbosity
    import Distribution.Text
             ( Text(parse), display )
    import Distribution.Compat.ReadP
        ( readP_to_S, string, skipSpaces )

    import Data.List                ( nub )
    import Data.Char                ( isSpace )
    import Data.Maybe               ( fromMaybe )

    -- -----------------------------------------------------------------------------
    -- Configuring

    configure :: Verbosity -> Maybe FilePath -> Maybe FilePath
              -> ProgramConfiguration -> IO (Compiler, ProgramConfiguration)
    configure verbosity hcPath _hcPkgPath conf = do

      (jhcProg, _, conf') <- requireProgramVersion verbosity
                               jhcProgram (orLaterVersion (Version [0,7,2] []))
                               (userMaybeSpecifyPath "jhc" hcPath conf)

      let Just version = programVersion jhcProg
          comp = Compiler {
            compilerId             = CompilerId JHC version,
            compilerLanguages      = jhcLanguages,
            compilerExtensions     = jhcLanguageExtensions
          }
      return (comp, conf')

    jhcLanguages :: [(Language, Flag)]
    jhcLanguages = [(Haskell98, "")]

    -- | The flags for the supported extensions
    jhcLanguageExtensions :: [(Extension, Flag)]
    jhcLanguageExtensions =
        [(TypeSynonymInstances       , "")
        ,(ForeignFunctionInterface   , "")
        ,(NoImplicitPrelude          , "--noprelude")
        ,(CPP                        , "-fcpp")
        ]

    getInstalledPackages :: Verbosity -> PackageDBStack -> ProgramConfiguration
                        -> IO PackageIndex
    getInstalledPackages verbosity _packageDBs conf = do
       -- jhc --list-libraries lists all available libraries.
       -- How shall I find out, whether they are global or local
       -- without checking all files and locations?
       str <- rawSystemProgramStdoutConf verbosity jhcProgram conf ["--list-libraries"]
       let pCheck :: [(a, String)] -> [a]
           pCheck rs = [ r | (r,s) <- rs, all isSpace s ]
       let parseLine ln =
              pCheck (readP_to_S
                 (skipSpaces >> string "Name:" >> skipSpaces >> parse) ln)
       return $
          PackageIndex.fromList $
          map (\p -> emptyInstalledPackageInfo {
                        InstalledPackageInfo.installedPackageId =
                           InstalledPackageId (display p),
                        InstalledPackageInfo.sourcePackageId = p
                     }) $
          concatMap parseLine $
          lines str

    -- -----------------------------------------------------------------------------
    -- Building

    -- | Building a package for JHC.
    -- Currently C source files are not supported.
    buildLib :: Verbosity -> PackageDescription -> LocalBuildInfo
                          -> Library            -> ComponentLocalBuildInfo -> IO ()
    buildLib verbosity pkg_descr lbi lib clbi = do
      let Just jhcProg = lookupProgram jhcProgram (withPrograms lbi)
      let libBi = libBuildInfo lib
      let args  = constructJHCCmdLine lbi libBi clbi (buildDir lbi) verbosity
      let pkgid = display (packageId pkg_descr)
          pfile = buildDir lbi </> "jhc-pkg.conf"
          hlfile= buildDir lbi </> (pkgid ++ ".hl")
      writeFileAtomic pfile $ jhcPkgConf pkg_descr
      rawSystemProgram verbosity jhcProg $
         ["--build-hl="++pfile, "-o", hlfile] ++
         args ++ map display (libModules lib)

    -- | Building an executable for JHC.
    -- Currently C source files are not supported.
    buildExe :: Verbosity -> PackageDescription -> LocalBuildInfo
                          -> Executable         -> ComponentLocalBuildInfo -> IO ()
    buildExe verbosity _pkg_descr lbi exe clbi = do
      let Just jhcProg = lookupProgram jhcProgram (withPrograms lbi)
      let exeBi = buildInfo exe
      let out   = buildDir lbi </> exeName exe
      let args  = constructJHCCmdLine lbi exeBi clbi (buildDir lbi) verbosity
      rawSystemProgram verbosity jhcProg (["-o",out] ++ args ++ [modulePath exe])

    constructJHCCmdLine :: LocalBuildInfo -> BuildInfo -> ComponentLocalBuildInfo
                        -> FilePath -> Verbosity -> [String]
    constructJHCCmdLine lbi bi clbi _odir verbosity =
            (if verbosity >= deafening then ["-v"] else [])
         ++ hcOptions JHC bi
         ++ languageToFlags (compiler lbi) (defaultLanguage bi)
         ++ extensionsToFlags (compiler lbi) (usedExtensions bi)
         ++ ["--noauto","-i-"]
         ++ concat [["-i", l] | l <- nub (hsSourceDirs bi)]
         ++ ["-i", autogenModulesDir lbi]
         ++ ["-optc" ++ opt | opt <- PD.ccOptions bi]
         -- It would be better if JHC would accept package names with versions,
         -- but JHC-0.7.2 doesn't accept this.
         -- Thus, we have to strip the version with 'pkgName'.
         ++ (concat [ ["-p", display (pkgName pkgid)]
                    | (_, pkgid) <- componentPackageDeps clbi ])

    jhcPkgConf :: PackageDescription -> String
    jhcPkgConf pd =
      let sline name sel = name ++ ": "++sel pd
          lib = fromMaybe (error "no library available") . library
          comma = intercalate "," . map display
      in unlines [sline "name" (display . pkgName . packageId)
                 ,sline "version" (display . pkgVersion . packageId)
                 ,sline "exposed-modules" (comma . PD.exposedModules . lib)
                 ,sline "hidden-modules" (comma . otherModules . libBuildInfo . lib)
                 ]

    installLib :: Verbosity -> FilePath -> FilePath -> PackageDescription -> Library -> IO ()
    installLib verb dest build_dir pkg_descr _ = do
        let p = display (packageId pkg_descr)++".hl"
        createDirectoryIfMissingVerbose verb True dest
        installOrdinaryFile verb (build_dir </> p) (dest </> p)

    installExe :: Verbosity -> FilePath -> FilePath -> (FilePath,FilePath) -> PackageDescription -> Executable -> IO ()
    installExe verb dest build_dir (progprefix,progsuffix) _ exe = do
        let exe_name = exeName exe
            src = exe_name </> exeExtension
            out   = (progprefix ++ exe_name ++ progsuffix) </> exeExtension
        createDirectoryIfMissingVerbose verb True dest
        installExecutableFile verb (build_dir </> src) (dest </> out)