    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Distribution.Simple.SrcDist
    -- Copyright   :  Simon Marlow 2004
    -- License     :  BSD3
    --
    -- Maintainer  :  cabal-devel@haskell.org
    -- Portability :  portable
    --
    -- This handles the @sdist@ command. The module exports an 'sdist' action but
    -- also some of the phases that make it up so that other tools can use just the
    -- bits they need. In particular the preparation of the tree of files to go
    -- into the source tarball is separated from actually building the source
    -- tarball.
    --
    -- The 'createArchive' action uses the external @tar@ program and assumes that
    -- it accepts the @-z@ flag. Neither of these assumptions are valid on Windows.
    -- The 'sdist' action now also does some distribution QA checks.

    -- NOTE: FIX: we don't have a great way of testing this module, since
    -- we can't easily look inside a tarball once its created.

    module Distribution.Simple.SrcDist (
      -- * The top level action
      sdist,

      -- ** Parts of 'sdist'
      printPackageProblems,
      prepareTree,
      createArchive,

      -- ** Snapshots
      prepareSnapshotTree,
      snapshotPackage,
      snapshotVersion,
      dateToSnapshotNumber,

      -- * Extracting the source files
      listPackageSources

      )  where

    import Distribution.PackageDescription hiding (Flag)
    import Distribution.PackageDescription.Check hiding (doesFileExist)
    import Distribution.Package
    import Distribution.ModuleName
    import qualified Distribution.ModuleName as ModuleName
    import Distribution.Version
    import Distribution.Simple.Utils
    import Distribution.Simple.Setup
    import Distribution.Simple.PreProcess
    import Distribution.Simple.LocalBuildInfo
    import Distribution.Simple.BuildPaths
    import Distribution.Simple.Program
    import Distribution.Text
    import Distribution.Verbosity

    import Control.Monad(when, unless, forM)
    import Data.Char (toLower)
    import Data.List (partition, isPrefixOf)
    import qualified Data.Map as Map
    import Data.Maybe (isNothing, catMaybes)
    import Data.Time (UTCTime, getCurrentTime, toGregorian, utctDay)
    import System.Directory ( doesFileExist )
    import System.IO (IOMode(WriteMode), hPutStrLn, withFile)
    import System.FilePath
             ( (</>), (<.>), dropExtension, isAbsolute )

    -- |Create a source distribution.
    sdist :: PackageDescription     -- ^information from the tarball
          -> Maybe LocalBuildInfo   -- ^Information from configure
          -> SDistFlags             -- ^verbosity & snapshot
          -> (FilePath -> FilePath) -- ^build prefix (temp dir)
          -> [PPSuffixHandler]      -- ^ extra preprocessors (includes suffixes)
          -> IO ()
    sdist pkg mb_lbi flags mkTmpDir pps =

      -- When given --list-sources, just output the list of sources to a file.
      case (sDistListSources flags) of
        Flag path -> withFile path WriteMode $ \outHandle -> do
          (ordinary, maybeExecutable) <- listPackageSources verbosity pkg pps
          mapM_ (hPutStrLn outHandle) ordinary
          mapM_ (hPutStrLn outHandle) maybeExecutable
          notice verbosity $ "List of package sources written to file '"
                             ++ path ++ "'"
        NoFlag    -> do
          -- do some QA
          printPackageProblems verbosity pkg

          when (isNothing mb_lbi) $
            warn verbosity "Cannot run preprocessors. Run 'configure' command first."

          date <- getCurrentTime
          let pkg' | snapshot  = snapshotPackage date pkg
                   | otherwise = pkg

          case flagToMaybe (sDistDirectory flags) of
            Just targetDir -> do
              generateSourceDir targetDir pkg'
              info verbosity $ "Source directory created: " ++ targetDir

            Nothing -> do
              createDirectoryIfMissingVerbose verbosity True tmpTargetDir
              withTempDirectory verbosity tmpTargetDir "sdist." $ \tmpDir -> do
                let targetDir = tmpDir </> tarBallName pkg'
                generateSourceDir targetDir pkg'
                targzFile <- createArchive verbosity pkg' mb_lbi tmpDir targetPref
                notice verbosity $ "Source tarball created: " ++ targzFile

      where
        generateSourceDir targetDir pkg' = do

          setupMessage verbosity "Building source dist for" (packageId pkg')
          prepareTree verbosity pkg' mb_lbi targetDir pps
          when snapshot $
            overwriteSnapshotPackageDesc verbosity pkg' targetDir

        verbosity = fromFlag (sDistVerbosity flags)
        snapshot  = fromFlag (sDistSnapshot flags)

        distPref     = fromFlag $ sDistDistPref flags
        targetPref   = distPref
        tmpTargetDir = mkTmpDir distPref

    -- | List all source files of a package. Returns a tuple of lists: first
    -- component is a list of ordinary files, second one is a list of those files
    -- that may be executable.
    listPackageSources :: Verbosity          -- ^ verbosity
                       -> PackageDescription -- ^ info from the cabal file
                       -> [PPSuffixHandler]  -- ^ extra preprocessors (include
                                             -- suffixes)
                       -> IO ([FilePath], [FilePath])
    listPackageSources verbosity pkg_descr0 pps = do
      -- Call helpers that actually do all work.
      ordinary        <- listPackageSourcesOrdinary        verbosity pkg_descr pps
      maybeExecutable <- listPackageSourcesMaybeExecutable pkg_descr
      return (ordinary, maybeExecutable)
      where
        pkg_descr = filterAutogenModule pkg_descr0

    -- | List those source files that may be executable (e.g. the configure script).
    listPackageSourcesMaybeExecutable :: PackageDescription -> IO [FilePath]
    listPackageSourcesMaybeExecutable pkg_descr =
      -- Extra source files.
      fmap concat . forM (extraSrcFiles pkg_descr) $ \fpath -> matchFileGlob fpath

    -- | List those source files that should be copied with ordinary permissions.
    listPackageSourcesOrdinary :: Verbosity
                               -> PackageDescription
                               -> [PPSuffixHandler]
                               -> IO [FilePath]
    listPackageSourcesOrdinary verbosity pkg_descr pps =
      fmap concat . sequence $
      [
        -- Library sources.
        withAllLib $ \Library { exposedModules = modules, libBuildInfo = libBi } ->
         allSourcesBuildInfo libBi pps modules

        -- Executables sources.
      , fmap concat
        . withAllExe $ \Executable { modulePath = mainPath, buildInfo = exeBi } -> do
           biSrcs  <- allSourcesBuildInfo exeBi pps []
           mainSrc <- findMainExeFile exeBi pps mainPath
           return (mainSrc:biSrcs)

        -- Test suites sources.
      , fmap concat
        . withAllTest $ \t -> do
           let bi  = testBuildInfo t
           case testInterface t of
             TestSuiteExeV10 _ mainPath -> do
               biSrcs <- allSourcesBuildInfo bi pps []
               srcMainFile <- do
                 ppFile <- findFileWithExtension (ppSuffixes pps)
                           (hsSourceDirs bi) (dropExtension mainPath)
                 case ppFile of
                   Nothing -> findFile (hsSourceDirs bi) mainPath
                   Just pp -> return pp
               return (srcMainFile:biSrcs)
             TestSuiteLibV09 _ m ->
               allSourcesBuildInfo bi pps [m]
             TestSuiteUnsupported tp -> die $ "Unsupported test suite type: "
                                       ++ show tp

        -- Benchmarks sources.
      , fmap concat
        . withAllBenchmark $ \bm -> do
           let  bi = benchmarkBuildInfo bm
           case benchmarkInterface bm of
             BenchmarkExeV10 _ mainPath -> do
               biSrcs <- allSourcesBuildInfo bi pps []
               srcMainFile <- do
                 ppFile <- findFileWithExtension (ppSuffixes pps)
                           (hsSourceDirs bi) (dropExtension mainPath)
                 case ppFile of
                   Nothing -> findFile (hsSourceDirs bi) mainPath
                   Just pp -> return pp
               return (srcMainFile:biSrcs)
             BenchmarkUnsupported tp -> die $ "Unsupported benchmark type: "
                                        ++ show tp

        -- Data files.
      , fmap concat
        . forM (dataFiles pkg_descr) $ \filename ->
           matchFileGlob (dataDir pkg_descr </> filename)

        -- Extra doc files.
      , fmap concat
        . forM (extraDocFiles pkg_descr) $ \ filename ->
          matchFileGlob filename

        -- License file(s).
      , return (licenseFiles pkg_descr)

        -- Install-include files.
      , withAllLib $ \ l -> do
           let lbi = libBuildInfo l
               relincdirs = "." : filter (not.isAbsolute) (includeDirs lbi)
           mapM (fmap snd . findIncludeFile relincdirs) (installIncludes lbi)

        -- Setup script, if it exists.
      , fmap (maybe [] (\f -> [f])) $ findSetupFile ""

        -- The .cabal file itself.
      , fmap (\d -> [d]) (defaultPackageDesc verbosity)

      ]
      where
        -- We have to deal with all libs and executables, so we have local
        -- versions of these functions that ignore the 'buildable' attribute:
        withAllLib       action = maybe (return []) action (library pkg_descr)
        withAllExe       action = mapM action (executables pkg_descr)
        withAllTest      action = mapM action (testSuites pkg_descr)
        withAllBenchmark action = mapM action (benchmarks pkg_descr)

    -- |Prepare a directory tree of source files.
    prepareTree :: Verbosity          -- ^verbosity
                -> PackageDescription -- ^info from the cabal file
                -> Maybe LocalBuildInfo
                -> FilePath           -- ^source tree to populate
                -> [PPSuffixHandler]  -- ^extra preprocessors (includes suffixes)
                -> IO ()
    prepareTree verbosity pkg_descr0 mb_lbi targetDir pps = do
      -- If the package was configured then we can run platform-independent
      -- pre-processors and include those generated files.
      case mb_lbi of
        Just lbi | not (null pps) -> do
          let lbi' = lbi{ buildDir = targetDir </> buildDir lbi }
          withAllComponentsInBuildOrder pkg_descr lbi' $ \c _ ->
            preprocessComponent pkg_descr c lbi' True verbosity pps
        _ -> return ()

      (ordinary, mExecutable)  <- listPackageSources verbosity pkg_descr0 pps
      installOrdinaryFiles        verbosity targetDir (zip (repeat []) ordinary)
      installMaybeExecutableFiles verbosity targetDir (zip (repeat []) mExecutable)
      maybeCreateDefaultSetupScript targetDir

      where
        pkg_descr = filterAutogenModule pkg_descr0

    -- | Find the setup script file, if it exists.
    findSetupFile :: FilePath -> IO (Maybe FilePath)
    findSetupFile targetDir = do
      hsExists  <- doesFileExist setupHs
      lhsExists <- doesFileExist setupLhs
      if hsExists
        then return (Just setupHs)
        else if lhsExists
             then return (Just setupLhs)
             else return Nothing
        where
          setupHs  = targetDir </> "Setup.hs"
          setupLhs = targetDir </> "Setup.lhs"

    -- | Create a default setup script in the target directory, if it doesn't exist.
    maybeCreateDefaultSetupScript :: FilePath -> IO ()
    maybeCreateDefaultSetupScript targetDir = do
      mSetupFile <- findSetupFile targetDir
      case mSetupFile of
        Just _setupFile -> return ()
        Nothing         -> do
          writeUTF8File (targetDir </> "Setup.hs") $ unlines [
            "import Distribution.Simple",
            "main = defaultMain"]

    -- | Find the main executable file.
    findMainExeFile :: BuildInfo -> [PPSuffixHandler] -> FilePath -> IO FilePath
    findMainExeFile exeBi pps mainPath = do
      ppFile <- findFileWithExtension (ppSuffixes pps) (hsSourceDirs exeBi)
                (dropExtension mainPath)
      case ppFile of
        Nothing -> findFile (hsSourceDirs exeBi) mainPath
        Just pp -> return pp

    -- | Given a list of include paths, try to find the include file named
    -- @f@. Return the name of the file and the full path, or exit with error if
    -- there's no such file.
    findIncludeFile :: [FilePath] -> String -> IO (String, FilePath)
    findIncludeFile [] f = die ("can't find include file " ++ f)
    findIncludeFile (d:ds) f = do
      let path = (d </> f)
      b <- doesFileExist path
      if b then return (f,path) else findIncludeFile ds f

    -- | Remove the auto-generated module ('Paths_*') from 'exposed-modules' and
    -- 'other-modules'.
    filterAutogenModule :: PackageDescription -> PackageDescription
    filterAutogenModule pkg_descr0 = mapLib filterAutogenModuleLib $
                                     mapAllBuildInfo filterAutogenModuleBI pkg_descr0
      where
        mapLib f pkg = pkg { library = fmap f (library pkg) }
        filterAutogenModuleLib lib = lib {
          exposedModules = filter (/=autogenModule) (exposedModules lib)
        }
        filterAutogenModuleBI bi = bi {
          otherModules   = filter (/=autogenModule) (otherModules bi)
        }
        autogenModule = autogenModuleName pkg_descr0

    -- | Prepare a directory tree of source files for a snapshot version.
    -- It is expected that the appropriate snapshot version has already been set
    -- in the package description, eg using 'snapshotPackage' or 'snapshotVersion'.
    --
    prepareSnapshotTree :: Verbosity          -- ^verbosity
                        -> PackageDescription -- ^info from the cabal file
                        -> Maybe LocalBuildInfo
                        -> FilePath           -- ^source tree to populate
                        -> [PPSuffixHandler]  -- ^extra preprocessors (includes
                                              -- suffixes)
                        -> IO ()
    prepareSnapshotTree verbosity pkg mb_lbi targetDir pps = do
      prepareTree verbosity pkg mb_lbi targetDir pps
      overwriteSnapshotPackageDesc verbosity pkg targetDir

    overwriteSnapshotPackageDesc :: Verbosity          -- ^verbosity
                                 -> PackageDescription -- ^info from the cabal file
                                 -> FilePath           -- ^source tree
                                 -> IO ()
    overwriteSnapshotPackageDesc verbosity pkg targetDir = do
        -- We could just writePackageDescription targetDescFile pkg_descr,
        -- but that would lose comments and formatting.
        descFile <- defaultPackageDesc verbosity
        withUTF8FileContents descFile $
          writeUTF8File (targetDir </> descFile)
            . unlines . map (replaceVersion (packageVersion pkg)) . lines

      where
        replaceVersion :: Version -> String -> String
        replaceVersion version line
          | "version:" `isPrefixOf` map toLower line
                      = "version: " ++ display version
          | otherwise = line

    -- | Modifies a 'PackageDescription' by appending a snapshot number
    -- corresponding to the given date.
    --
    snapshotPackage :: UTCTime -> PackageDescription -> PackageDescription
    snapshotPackage date pkg =
      pkg {
        package = pkgid { pkgVersion = snapshotVersion date (pkgVersion pkgid) }
      }
      where pkgid = packageId pkg

    -- | Modifies a 'Version' by appending a snapshot number corresponding
    -- to the given date.
    --
    snapshotVersion :: UTCTime -> Version -> Version
    snapshotVersion date version = version {
        versionBranch = versionBranch version
                     ++ [dateToSnapshotNumber date]
      }

    -- | Given a date produce a corresponding integer representation.
    -- For example given a date @18/03/2008@ produce the number @20080318@.
    --
    dateToSnapshotNumber :: UTCTime -> Int
    dateToSnapshotNumber date = case toGregorian (utctDay date) of
                                (year, month, day) ->
                                    fromIntegral year * 10000
                                  + month             * 100
                                  + day

    -- | Callback type for use by sdistWith.
    type CreateArchiveFun = Verbosity               -- ^verbosity
                            -> PackageDescription   -- ^info from cabal file
                            -> Maybe LocalBuildInfo -- ^info from configure
                            -> FilePath             -- ^source tree to archive
                            -> FilePath             -- ^name of archive to create
                            -> IO FilePath

    -- | Create an archive from a tree of source files, and clean up the tree.
    createArchive :: CreateArchiveFun
    createArchive verbosity pkg_descr mb_lbi tmpDir targetPref = do
      let tarBallFilePath = targetPref </> tarBallName pkg_descr <.> "tar.gz"

      (tarProg, _) <- requireProgram verbosity tarProgram
                        (maybe defaultProgramConfiguration withPrograms mb_lbi)
      let formatOptSupported = maybe False (== "YES") $
                               Map.lookup "Supports --format"
                               (programProperties tarProg)
      runProgram verbosity tarProg $
        -- Hmm: I could well be skating on thinner ice here by using the -C option
        -- (=> seems to be supported at least by GNU and *BSD tar) [The
        -- prev. solution used pipes and sub-command sequences to set up the paths
        -- correctly, which is problematic in a Windows setting.]
        ["-czf", tarBallFilePath, "-C", tmpDir]
        ++ (if formatOptSupported then ["--format", "ustar"] else [])
        ++ [tarBallName pkg_descr]
      return tarBallFilePath

    -- | Given a buildinfo, return the names of all source files.
    allSourcesBuildInfo :: BuildInfo
                           -> [PPSuffixHandler] -- ^ Extra preprocessors
                           -> [ModuleName]      -- ^ Exposed modules
                           -> IO [FilePath]
    allSourcesBuildInfo bi pps modules = do
      let searchDirs = hsSourceDirs bi
      sources <- fmap concat $ sequence $
        [ let file = ModuleName.toFilePath module_
          in findAllFilesWithExtension suffixes searchDirs file
             >>= nonEmpty (notFound module_) return
        | module_ <- modules ++ otherModules bi ]
      bootFiles <- sequence
        [ let file = ModuleName.toFilePath module_
              fileExts = ["hs-boot", "lhs-boot"]
          in findFileWithExtension fileExts (hsSourceDirs bi) file
        | module_ <- modules ++ otherModules bi ]

      return $ sources ++ catMaybes bootFiles ++ cSources bi ++ jsSources bi

      where
        nonEmpty x _ [] = x
        nonEmpty _ f xs = f xs
        suffixes = ppSuffixes pps ++ ["hs", "lhs"]
        notFound m = die $ "Error: Could not find module: " ++ display m
                     ++ " with any suffix: " ++ show suffixes

    printPackageProblems :: Verbosity -> PackageDescription -> IO ()
    printPackageProblems verbosity pkg_descr = do
      ioChecks      <- checkPackageFiles pkg_descr "."
      let pureChecks = checkConfiguredPackage pkg_descr
          isDistError (PackageDistSuspicious     _) = False
          isDistError (PackageDistSuspiciousWarn _) = False
          isDistError _                             = True
          (errors, warnings) = partition isDistError (pureChecks ++ ioChecks)
      unless (null errors) $
          notice verbosity $ "Distribution quality errors:\n"
                          ++ unlines (map explanation errors)
      unless (null warnings) $
          notice verbosity $ "Distribution quality warnings:\n"
                          ++ unlines (map explanation warnings)
      unless (null errors) $
          notice verbosity
            "Note: the public hackage server would reject this package."

    ------------------------------------------------------------

    -- | The name of the tarball without extension
    --
    tarBallName :: PackageDescription -> String
    tarBallName = display . packageId

    mapAllBuildInfo :: (BuildInfo -> BuildInfo)
                    -> (PackageDescription -> PackageDescription)
    mapAllBuildInfo f pkg = pkg {
        library     = fmap mapLibBi (library pkg),
        executables = fmap mapExeBi (executables pkg),
        testSuites  = fmap mapTestBi (testSuites pkg),
        benchmarks  = fmap mapBenchBi (benchmarks pkg)
      }
      where
        mapLibBi lib  = lib { libBuildInfo       = f (libBuildInfo lib) }
        mapExeBi exe  = exe { buildInfo          = f (buildInfo exe) }
        mapTestBi t   = t   { testBuildInfo      = f (testBuildInfo t) }
        mapBenchBi bm = bm  { benchmarkBuildInfo = f (benchmarkBuildInfo bm) }