    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Distribution.Simple.Install
    -- Copyright   :  Isaac Jones 2003-2004
    -- License     :  BSD3
    --
    -- Maintainer  :  cabal-devel@haskell.org
    -- Portability :  portable
    --
    -- This is the entry point into installing a built package. Performs the
    -- \"@.\/setup install@\" and \"@.\/setup copy@\" actions. It moves files into
    -- place based on the prefix argument. It does the generic bits and then calls
    -- compiler-specific functions to do the rest.

    module Distribution.Simple.Install (
            install,
      ) where

    import Distribution.PackageDescription (
            PackageDescription(..), BuildInfo(..), Library(..),
            hasLibs, withLib, hasExes, withExe )
    import Distribution.Package (Package(..))
    import Distribution.Simple.LocalBuildInfo (
            LocalBuildInfo(..), InstallDirs(..), absoluteInstallDirs,
            substPathTemplate, withLibLBI)
    import Distribution.Simple.BuildPaths (haddockName, haddockPref)
    import Distribution.Simple.Utils
             ( createDirectoryIfMissingVerbose
             , installDirectoryContents, installOrdinaryFile, isInSearchPath
             , die, info, notice, warn, matchDirFileGlob )
    import Distribution.Simple.Compiler
             ( CompilerFlavor(..), compilerFlavor )
    import Distribution.Simple.Setup (CopyFlags(..), fromFlag)

    import qualified Distribution.Simple.GHC   as GHC
    import qualified Distribution.Simple.GHCJS as GHCJS
    import qualified Distribution.Simple.JHC   as JHC
    import qualified Distribution.Simple.LHC   as LHC
    import qualified Distribution.Simple.UHC   as UHC
    import qualified Distribution.Simple.HaskellSuite as HaskellSuite

    import Control.Monad (when, unless)
    import System.Directory
             ( doesDirectoryExist, doesFileExist )
    import System.FilePath
             ( takeFileName, takeDirectory, (</>), isAbsolute )

    import Distribution.Verbosity
    import Distribution.Text
             ( display )

    -- |Perform the \"@.\/setup install@\" and \"@.\/setup copy@\"
    -- actions.  Move files into place based on the prefix argument.

    install :: PackageDescription -- ^information from the .cabal file
            -> LocalBuildInfo -- ^information from the configure step
            -> CopyFlags -- ^flags sent to copy or install
            -> IO ()
    install pkg_descr lbi flags = do
      let distPref  = fromFlag (copyDistPref flags)
          verbosity = fromFlag (copyVerbosity flags)
          copydest  = fromFlag (copyDest flags)
          installDirs@(InstallDirs {
             bindir     = binPref,
             libdir     = libPref,
    --         dynlibdir  = dynlibPref, --see TODO below
             datadir    = dataPref,
             docdir     = docPref,
             htmldir    = htmlPref,
             haddockdir = interfacePref,
             includedir = incPref})
                 = absoluteInstallDirs pkg_descr lbi copydest

          --TODO: decide if we need the user to be able to control the libdir
          -- for shared libs independently of the one for static libs. If so
          -- it should also have a flag in the command line UI
          -- For the moment use dynlibdir = libdir
          dynlibPref = libPref
          progPrefixPref = substPathTemplate (packageId pkg_descr) lbi (progPrefix lbi)
          progSuffixPref = substPathTemplate (packageId pkg_descr) lbi (progSuffix lbi)

      docExists <- doesDirectoryExist $ haddockPref distPref pkg_descr
      info verbosity ("directory " ++ haddockPref distPref pkg_descr ++
                      " does exist: " ++ show docExists)

      installDataFiles verbosity pkg_descr dataPref

      when docExists $ do
          createDirectoryIfMissingVerbose verbosity True htmlPref
          installDirectoryContents verbosity
              (haddockPref distPref pkg_descr) htmlPref
          -- setPermissionsRecursive [Read] htmlPref
          -- The haddock interface file actually already got installed
          -- in the recursive copy, but now we install it where we actually
          -- want it to be (normally the same place). We could remove the
          -- copy in htmlPref first.
          let haddockInterfaceFileSrc  = haddockPref distPref pkg_descr
                                                       </> haddockName pkg_descr
              haddockInterfaceFileDest = interfacePref </> haddockName pkg_descr
          -- We only generate the haddock interface file for libs, So if the
          -- package consists only of executables there will not be one:
          exists <- doesFileExist haddockInterfaceFileSrc
          when exists $ do
            createDirectoryIfMissingVerbose verbosity True interfacePref
            installOrdinaryFile verbosity haddockInterfaceFileSrc
                                          haddockInterfaceFileDest

      let lfiles = licenseFiles pkg_descr
      unless (null lfiles) $ do
        createDirectoryIfMissingVerbose verbosity True docPref
        sequence_
          [ installOrdinaryFile verbosity lfile (docPref </> takeFileName lfile)
          | lfile <- lfiles ]

      let buildPref = buildDir lbi
      when (hasLibs pkg_descr) $
        notice verbosity ("Installing library in " ++ libPref)
      when (hasExes pkg_descr) $ do
        notice verbosity ("Installing executable(s) in " ++ binPref)
        inPath <- isInSearchPath binPref
        when (not inPath) $
          warn verbosity ("The directory " ++ binPref
                          ++ " is not in the system search path.")

      -- install include files for all compilers - they may be needed to compile
      -- haskell files (using the CPP extension)
      when (hasLibs pkg_descr) $ installIncludeFiles verbosity pkg_descr incPref

      case compilerFlavor (compiler lbi) of
         GHC  -> do withLibLBI pkg_descr lbi $
                      GHC.installLib verbosity lbi libPref dynlibPref buildPref pkg_descr
                    withExe pkg_descr $
                      GHC.installExe verbosity lbi installDirs buildPref (progPrefixPref, progSuffixPref) pkg_descr
         GHCJS-> do withLibLBI pkg_descr lbi $
                      GHCJS.installLib verbosity lbi libPref dynlibPref buildPref pkg_descr
                    withExe pkg_descr $
                      GHCJS.installExe verbosity lbi installDirs buildPref (progPrefixPref, progSuffixPref) pkg_descr
         LHC  -> do withLibLBI pkg_descr lbi $
                      LHC.installLib verbosity lbi libPref dynlibPref buildPref pkg_descr
                    withExe pkg_descr $
                      LHC.installExe verbosity lbi installDirs buildPref (progPrefixPref, progSuffixPref) pkg_descr
         JHC  -> do withLib pkg_descr $
                      JHC.installLib verbosity libPref buildPref pkg_descr
                    withExe pkg_descr $
                      JHC.installExe verbosity binPref buildPref (progPrefixPref, progSuffixPref) pkg_descr
         UHC  -> do withLib pkg_descr $ UHC.installLib verbosity lbi libPref dynlibPref buildPref pkg_descr
         HaskellSuite {} ->
           withLib pkg_descr $
             HaskellSuite.installLib verbosity lbi libPref dynlibPref buildPref pkg_descr
         _    -> die $ "installing with "
                    ++ display (compilerFlavor (compiler lbi))
                    ++ " is not implemented"
      -- register step should be performed by caller.

    -- | Install the files listed in data-files
    --
    installDataFiles :: Verbosity -> PackageDescription -> FilePath -> IO ()
    installDataFiles verbosity pkg_descr destDataDir =
      flip mapM_ (dataFiles pkg_descr) $ \ file -> do
        let srcDataDir = dataDir pkg_descr
        files <- matchDirFileGlob srcDataDir file
        let dir = takeDirectory file
        createDirectoryIfMissingVerbose verbosity True (destDataDir </> dir)
        sequence_ [ installOrdinaryFile verbosity (srcDataDir  </> file')
                                                  (destDataDir </> file')
                  | file' <- files ]

    -- | Install the files listed in install-includes
    --
    installIncludeFiles :: Verbosity -> PackageDescription -> FilePath -> IO ()
    installIncludeFiles verbosity
      PackageDescription { library = Just lib } destIncludeDir = do

      incs <- mapM (findInc relincdirs) (installIncludes lbi)
      sequence_
        [ do createDirectoryIfMissingVerbose verbosity True destDir
             installOrdinaryFile verbosity srcFile destFile
        | (relFile, srcFile) <- incs
        , let destFile = destIncludeDir </> relFile
              destDir  = takeDirectory destFile ]
      where
       relincdirs = "." : filter (not.isAbsolute) (includeDirs lbi)
       lbi = libBuildInfo lib

       findInc []         file = die ("can't find include file " ++ file)
       findInc (dir:dirs) file = do
         let path = dir </> file
         exists <- doesFileExist path
         if exists then return (file, path) else findInc dirs file
    installIncludeFiles _ _ _ = die "installIncludeFiles: Can't happen?"