    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Distribution.Simple.Register
    -- Copyright   :  Isaac Jones 2003-2004
    -- License     :  BSD3
    --
    -- Maintainer  :  cabal-devel@haskell.org
    -- Portability :  portable
    --
    -- This module deals with registering and unregistering packages. There are a
    -- couple ways it can do this, one is to do it directly. Another is to generate
    -- a script that can be run later to do it. The idea here being that the user
    -- is shielded from the details of what command to use for package registration
    -- for a particular compiler. In practice this aspect was not especially
    -- popular so we also provide a way to simply generate the package registration
    -- file which then must be manually passed to @ghc-pkg@. It is possible to
    -- generate registration information for where the package is to be installed,
    -- or alternatively to register the package in place in the build tree. The
    -- latter is occasionally handy, and will become more important when we try to
    -- build multi-package systems.
    --
    -- This module does not delegate anything to the per-compiler modules but just
    -- mixes it all in in this module, which is rather unsatisfactory. The script
    -- generation and the unregister feature are not well used or tested.

    module Distribution.Simple.Register (
        register,
        unregister,

        initPackageDB,
        invokeHcPkg,
        registerPackage,
        generateRegistrationInfo,
        inplaceInstalledPackageInfo,
        absoluteInstalledPackageInfo,
        generalInstalledPackageInfo,
      ) where

    import Distribution.Simple.LocalBuildInfo
             ( LocalBuildInfo(..), ComponentLocalBuildInfo(..)
             , ComponentName(..), getComponentLocalBuildInfo
             , LibraryName(..)
             , InstallDirs(..), absoluteInstallDirs )
    import Distribution.Simple.BuildPaths (haddockName)

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

    import Distribution.Simple.Compiler
             ( compilerVersion, Compiler, CompilerFlavor(..), compilerFlavor
             , PackageDB, PackageDBStack, absolutePackageDBPaths
             , registrationPackageDB )
    import Distribution.Simple.Program
             ( ProgramConfiguration, runProgramInvocation )
    import Distribution.Simple.Program.Script
             ( invocationAsSystemScript )
    import           Distribution.Simple.Program.HcPkg (HcPkgInfo)
    import qualified Distribution.Simple.Program.HcPkg as HcPkg
    import Distribution.Simple.Setup
             ( RegisterFlags(..), CopyDest(..)
             , fromFlag, fromFlagOrDefault, flagToMaybe )
    import Distribution.PackageDescription
             ( PackageDescription(..), Library(..), BuildInfo(..), libModules )
    import Distribution.Package
             ( Package(..), packageName, InstalledPackageId(..) )
    import Distribution.InstalledPackageInfo
             ( InstalledPackageInfo, InstalledPackageInfo_(InstalledPackageInfo)
             , showInstalledPackageInfo )
    import qualified Distribution.InstalledPackageInfo as IPI
    import Distribution.Simple.Utils
             ( writeUTF8File, writeFileAtomic, setFileExecutable
             , die, notice, setupMessage, shortRelativePath )
    import Distribution.System
             ( OS(..), buildOS )
    import Distribution.Text
             ( display )
    import Distribution.Version ( Version(..) )
    import Distribution.Verbosity as Verbosity
             ( Verbosity, normal )

    import System.FilePath ((</>), (<.>), isAbsolute)
    import System.Directory
             ( getCurrentDirectory )

    import Control.Monad (when)
    import Data.Maybe
             ( isJust, fromMaybe, maybeToList )
    import Data.List
             ( partition, nub )
    import qualified Data.ByteString.Lazy.Char8 as BS.Char8

    -- -----------------------------------------------------------------------------
    -- Registration

    register :: PackageDescription -> LocalBuildInfo
             -> RegisterFlags -- ^Install in the user's database?; verbose
             -> IO ()
    register pkg@PackageDescription { library       = Just lib  } lbi regFlags
      = do
        let clbi = getComponentLocalBuildInfo lbi CLibName

        absPackageDBs    <- absolutePackageDBPaths packageDbs
        installedPkgInfo <- generateRegistrationInfo
                               verbosity pkg lib lbi clbi inplace reloc distPref
                               (registrationPackageDB absPackageDBs)

        when (fromFlag (regPrintId regFlags)) $ do
          putStrLn (display (IPI.installedPackageId installedPkgInfo))

         -- Three different modes:
        case () of
         _ | modeGenerateRegFile   -> writeRegistrationFile installedPkgInfo
           | modeGenerateRegScript -> writeRegisterScript   installedPkgInfo
           | otherwise             -> registerPackage verbosity
                                        installedPkgInfo pkg lbi inplace packageDbs

      where
        modeGenerateRegFile = isJust (flagToMaybe (regGenPkgConf regFlags))
        regFile             = fromMaybe (display (packageId pkg) <.> "conf")
                                        (fromFlag (regGenPkgConf regFlags))

        modeGenerateRegScript = fromFlag (regGenScript regFlags)

        inplace   = fromFlag (regInPlace regFlags)
        reloc     = relocatable lbi
        -- FIXME: there's really no guarantee this will work.
        -- registering into a totally different db stack can
        -- fail if dependencies cannot be satisfied.
        packageDbs = nub $ withPackageDB lbi
                        ++ maybeToList (flagToMaybe  (regPackageDB regFlags))
        distPref  = fromFlag (regDistPref regFlags)
        verbosity = fromFlag (regVerbosity regFlags)

        writeRegistrationFile installedPkgInfo = do
          notice verbosity ("Creating package registration file: " ++ regFile)
          writeUTF8File regFile (showInstalledPackageInfo installedPkgInfo)

        writeRegisterScript installedPkgInfo =
          case compilerFlavor (compiler lbi) of
            JHC -> notice verbosity "Registration scripts not needed for jhc"
            UHC -> notice verbosity "Registration scripts not needed for uhc"
            _   -> withHcPkg
                   "Registration scripts are not implemented for this compiler"
                   (compiler lbi) (withPrograms lbi)
                   (writeHcPkgRegisterScript verbosity installedPkgInfo packageDbs)

    register _ _ regFlags = notice verbosity "No package to register"
      where
        verbosity = fromFlag (regVerbosity regFlags)

    generateRegistrationInfo :: Verbosity
                             -> PackageDescription
                             -> Library
                             -> LocalBuildInfo
                             -> ComponentLocalBuildInfo
                             -> Bool
                             -> Bool
                             -> FilePath
                             -> PackageDB
                             -> IO InstalledPackageInfo
    generateRegistrationInfo verbosity pkg lib lbi clbi inplace reloc distPref packageDb = do
      --TODO: eliminate pwd!
      pwd <- getCurrentDirectory

      --TODO: the method of setting the InstalledPackageId is compiler specific
      --      this aspect should be delegated to a per-compiler helper.
      let comp = compiler lbi
      ipid <-
        case compilerFlavor comp of
         GHC | compilerVersion comp >= Version [6,11] [] -> do
                s <- GHC.libAbiHash verbosity pkg lbi lib clbi
                return (InstalledPackageId (display (packageId pkg) ++ '-':s))
         GHCJS -> do
                s <- GHCJS.libAbiHash verbosity pkg lbi lib clbi
                return (InstalledPackageId (display (packageId pkg) ++ '-':s))
         _other -> do
                return (InstalledPackageId (display (packageId pkg)))

      installedPkgInfo <-
        if inplace
          then return (inplaceInstalledPackageInfo pwd distPref
                         pkg ipid lib lbi clbi)
        else if reloc
          then relocRegistrationInfo verbosity
                         pkg lib lbi clbi ipid packageDb
          else return (absoluteInstalledPackageInfo
                         pkg ipid lib lbi clbi)

      return installedPkgInfo{ IPI.installedPackageId = ipid }

    relocRegistrationInfo :: Verbosity
                          -> PackageDescription
                          -> Library
                          -> LocalBuildInfo
                          -> ComponentLocalBuildInfo
                          -> InstalledPackageId
                          -> PackageDB
                          -> IO InstalledPackageInfo
    relocRegistrationInfo verbosity pkg lib lbi clbi ipid packageDb =
      case (compilerFlavor (compiler lbi)) of
        GHC -> do fs <- GHC.pkgRoot verbosity lbi packageDb
                  return (relocatableInstalledPackageInfo
                            pkg ipid lib lbi clbi fs)
        _   -> die "Distribution.Simple.Register.relocRegistrationInfo: \
                   \not implemented for this compiler"

    -- | Create an empty package DB at the specified location.
    initPackageDB :: Verbosity -> Compiler -> ProgramConfiguration -> FilePath
                     -> IO ()
    initPackageDB verbosity comp conf dbPath =
      case compilerFlavor comp of
        HaskellSuite {} -> HaskellSuite.initPackageDB verbosity conf dbPath
        _               -> withHcPkg "Distribution.Simple.Register.initPackageDB: \
                                     \not implemented for this compiler" comp conf
                                     (\hpi -> HcPkg.init hpi verbosity dbPath)

    -- | Run @hc-pkg@ using a given package DB stack, directly forwarding the
    -- provided command-line arguments to it.
    invokeHcPkg :: Verbosity -> Compiler -> ProgramConfiguration -> PackageDBStack
                    -> [String] -> IO ()
    invokeHcPkg verbosity comp conf dbStack extraArgs =
      withHcPkg "invokeHcPkg" comp conf
        (\hpi -> HcPkg.invoke hpi verbosity dbStack extraArgs)

    withHcPkg :: String -> Compiler -> ProgramConfiguration
              -> (HcPkgInfo -> IO a) -> IO a
    withHcPkg name comp conf f =
      case compilerFlavor comp of
        GHC   -> f (GHC.hcPkgInfo conf)
        GHCJS -> f (GHCJS.hcPkgInfo conf)
        LHC   -> f (LHC.hcPkgInfo conf)
        _     -> die ("Distribution.Simple.Register." ++ name ++ ":\
                      \not implemented for this compiler")

    registerPackage :: Verbosity
                    -> InstalledPackageInfo
                    -> PackageDescription
                    -> LocalBuildInfo
                    -> Bool
                    -> PackageDBStack
                    -> IO ()
    registerPackage verbosity installedPkgInfo pkg lbi inplace packageDbs = do
      let msg = if inplace
                then "In-place registering"
                else "Registering"
      setupMessage verbosity msg (packageId pkg)
      case compilerFlavor (compiler lbi) of
        GHC   -> GHC.registerPackage   verbosity installedPkgInfo pkg lbi inplace packageDbs
        GHCJS -> GHCJS.registerPackage verbosity installedPkgInfo pkg lbi inplace packageDbs
        LHC   -> LHC.registerPackage   verbosity installedPkgInfo pkg lbi inplace packageDbs
        UHC   -> UHC.registerPackage   verbosity installedPkgInfo pkg lbi inplace packageDbs
        JHC   -> notice verbosity "Registering for jhc (nothing to do)"
        HaskellSuite {} ->
          HaskellSuite.registerPackage verbosity installedPkgInfo pkg lbi inplace packageDbs
        _    -> die "Registering is not implemented for this compiler"

    writeHcPkgRegisterScript :: Verbosity
                             -> InstalledPackageInfo
                             -> PackageDBStack
                             -> HcPkgInfo
                             -> IO ()
    writeHcPkgRegisterScript verbosity installedPkgInfo packageDbs hpi = do
      let invocation  = HcPkg.reregisterInvocation hpi Verbosity.normal
                          packageDbs (Right installedPkgInfo)
          regScript   = invocationAsSystemScript buildOS invocation

      notice verbosity ("Creating package registration script: " ++ regScriptFileName)
      writeUTF8File regScriptFileName regScript
      setFileExecutable regScriptFileName

    regScriptFileName :: FilePath
    regScriptFileName = case buildOS of
                            Windows -> "register.bat"
                            _       -> "register.sh"

    -- -----------------------------------------------------------------------------
    -- Making the InstalledPackageInfo

    -- | Construct 'InstalledPackageInfo' for a library in a package, given a set
    -- of installation directories.
    --
    generalInstalledPackageInfo
      :: ([FilePath] -> [FilePath]) -- ^ Translate relative include dir paths to
                                    -- absolute paths.
      -> PackageDescription
      -> InstalledPackageId
      -> Library
      -> LocalBuildInfo
      -> ComponentLocalBuildInfo
      -> InstallDirs FilePath
      -> InstalledPackageInfo
    generalInstalledPackageInfo adjustRelIncDirs pkg ipid lib lbi clbi installDirs =
      InstalledPackageInfo {
        IPI.installedPackageId = ipid,
        IPI.sourcePackageId    = packageId   pkg,
        IPI.packageKey         = pkgKey lbi,
        IPI.license            = license     pkg,
        IPI.copyright          = copyright   pkg,
        IPI.maintainer         = maintainer  pkg,
        IPI.author             = author      pkg,
        IPI.stability          = stability   pkg,
        IPI.homepage           = homepage    pkg,
        IPI.pkgUrl             = pkgUrl      pkg,
        IPI.synopsis           = synopsis    pkg,
        IPI.description        = description pkg,
        IPI.category           = category    pkg,
        IPI.exposed            = libExposed  lib,
        IPI.exposedModules     = map fixupSelf (componentExposedModules clbi),
        IPI.hiddenModules      = otherModules bi,
        IPI.instantiatedWith   = map (\(k,(p,n)) ->
                                       (k,IPI.OriginalModule (IPI.installedPackageId p) n))
                                     (instantiatedWith lbi),
        IPI.trusted            = IPI.trusted IPI.emptyInstalledPackageInfo,
        IPI.importDirs         = [ libdir installDirs | hasModules ],
        -- Note. the libsubdir and datasubdir templates have already been expanded
        -- into libdir and datadir.
        IPI.libraryDirs        = if hasLibrary
                                   then libdir installDirs : extraLibDirs bi
                                   else                      extraLibDirs bi,
        IPI.dataDir            = datadir installDirs,
        IPI.hsLibraries        = [ libname
                                 | LibraryName libname <- componentLibraries clbi
                                 , hasLibrary ],
        IPI.extraLibraries     = extraLibs bi,
        IPI.extraGHCiLibraries = extraGHCiLibs bi,
        IPI.includeDirs        = absinc ++ adjustRelIncDirs relinc,
        IPI.includes           = includes bi,
        IPI.depends            = map fst (componentPackageDeps clbi),
        IPI.ccOptions          = [], -- Note. NOT ccOptions bi!
                                     -- We don't want cc-options to be propagated
                                     -- to C compilations in other packages.
        IPI.ldOptions          = ldOptions bi,
        IPI.frameworkDirs      = [],
        IPI.frameworks         = frameworks bi,
        IPI.haddockInterfaces  = [haddockdir installDirs </> haddockName pkg],
        IPI.haddockHTMLs       = [htmldir installDirs],
        IPI.pkgRoot            = Nothing
      }
      where
        bi = libBuildInfo lib
        (absinc, relinc) = partition isAbsolute (includeDirs bi)
        hasModules = not $ null (libModules lib)
        hasLibrary = hasModules || not (null (cSources bi))
                                || (not (null (jsSources bi)) &&
                                    compilerFlavor (compiler lbi) == GHCJS)

        -- Since we currently don't decide the InstalledPackageId of our package
        -- until just before we register, we didn't have one for the re-exports
        -- of modules defined within this package, so we used an empty one that
        -- we fill in here now that we know what it is. It's a bit of a hack,
        -- we ought really to decide the InstalledPackageId ahead of time.
        fixupSelf (IPI.ExposedModule n o o') =
            IPI.ExposedModule n (fmap fixupOriginalModule o)
                                (fmap fixupOriginalModule o')
        fixupOriginalModule (IPI.OriginalModule i m) = IPI.OriginalModule (fixupIpid i) m
        fixupIpid (InstalledPackageId []) = ipid
        fixupIpid x = x

    -- | Construct 'InstalledPackageInfo' for a library that is in place in the
    -- build tree.
    --
    -- This function knows about the layout of in place packages.
    --
    inplaceInstalledPackageInfo :: FilePath -- ^ top of the build tree
                                -> FilePath -- ^ location of the dist tree
                                -> PackageDescription
                                -> InstalledPackageId
                                -> Library
                                -> LocalBuildInfo
                                -> ComponentLocalBuildInfo
                                -> InstalledPackageInfo
    inplaceInstalledPackageInfo inplaceDir distPref pkg ipid lib lbi clbi =
        generalInstalledPackageInfo adjustRelativeIncludeDirs
                                    pkg ipid lib lbi clbi installDirs
      where
        adjustRelativeIncludeDirs = map (inplaceDir </>)
        installDirs =
          (absoluteInstallDirs pkg lbi NoCopyDest) {
            libdir     = inplaceDir </> buildDir lbi,
            datadir    = inplaceDir </> dataDir pkg,
            docdir     = inplaceDocdir,
            htmldir    = inplaceHtmldir,
            haddockdir = inplaceHtmldir
          }
        inplaceDocdir  = inplaceDir </> distPref </> "doc"
        inplaceHtmldir = inplaceDocdir </> "html" </> display (packageName pkg)

    -- | Construct 'InstalledPackageInfo' for the final install location of a
    -- library package.
    --
    -- This function knows about the layout of installed packages.
    --
    absoluteInstalledPackageInfo :: PackageDescription
                                 -> InstalledPackageId
                                 -> Library
                                 -> LocalBuildInfo
                                 -> ComponentLocalBuildInfo
                                 -> InstalledPackageInfo
    absoluteInstalledPackageInfo pkg ipid lib lbi clbi =
        generalInstalledPackageInfo adjustReativeIncludeDirs
                                    pkg ipid lib lbi clbi installDirs
      where
        -- For installed packages we install all include files into one dir,
        -- whereas in the build tree they may live in multiple local dirs.
        adjustReativeIncludeDirs _
          | null (installIncludes bi) = []
          | otherwise                 = [includedir installDirs]
        bi = libBuildInfo lib
        installDirs = absoluteInstallDirs pkg lbi NoCopyDest

    relocatableInstalledPackageInfo :: PackageDescription
                                    -> InstalledPackageId
                                    -> Library
                                    -> LocalBuildInfo
                                    -> ComponentLocalBuildInfo
                                    -> FilePath
                                    -> InstalledPackageInfo
    relocatableInstalledPackageInfo pkg ipid lib lbi clbi pkgroot =
        generalInstalledPackageInfo adjustReativeIncludeDirs
                                    pkg ipid lib lbi clbi installDirs
      where
        -- For installed packages we install all include files into one dir,
        -- whereas in the build tree they may live in multiple local dirs.
        adjustReativeIncludeDirs _
          | null (installIncludes bi) = []
          | otherwise                 = [includedir installDirs]
        bi = libBuildInfo lib

        installDirs = fmap (("${pkgroot}" </>) . shortRelativePath pkgroot)
                    $ absoluteInstallDirs pkg lbi NoCopyDest

    -- -----------------------------------------------------------------------------
    -- Unregistration

    unregister :: PackageDescription -> LocalBuildInfo -> RegisterFlags -> IO ()
    unregister pkg lbi regFlags = do
      let pkgid     = packageId pkg
          genScript = fromFlag (regGenScript regFlags)
          verbosity = fromFlag (regVerbosity regFlags)
          packageDb = fromFlagOrDefault (registrationPackageDB (withPackageDB lbi))
                                        (regPackageDB regFlags)
          unreg hpi =
            let invocation = HcPkg.unregisterInvocation
                               hpi Verbosity.normal packageDb pkgid
            in if genScript
                 then writeFileAtomic unregScriptFileName
                        (BS.Char8.pack $ invocationAsSystemScript buildOS invocation)
                 else runProgramInvocation verbosity invocation
      setupMessage verbosity "Unregistering" pkgid
      withHcPkg "unregistering is only implemented for GHC and GHCJS"
        (compiler lbi) (withPrograms lbi) unreg

    unregScriptFileName :: FilePath
    unregScriptFileName = case buildOS of
                              Windows -> "unregister.bat"
                              _       -> "unregister.sh"