    -----------------------------------------------------------------------------
    -- |
    -- 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
             ( PackageDescription(..), BuildInfo(..), Executable(..), Library(..)
             , TestSuite(..), TestSuiteInterface(..), Benchmark(..)
             , BenchmarkInterface(..) )
    import Distribution.PackageDescription.Check
             ( PackageCheck(..), checkConfiguredPackage, checkPackageFiles )
    import Distribution.Package
             ( PackageIdentifier(pkgVersion), Package(..), packageVersion )
    import Distribution.ModuleName (ModuleName)
    import qualified Distribution.ModuleName as ModuleName
    import Distribution.Version
             ( Version(versionBranch) )
    import Distribution.Simple.Utils
             ( createDirectoryIfMissingVerbose, withUTF8FileContents, writeUTF8File
             , installOrdinaryFiles, installMaybeExecutableFiles
             , findFile, findFileWithExtension, matchFileGlob
             , withTempDirectory, defaultPackageDesc
             , die, warn, notice, info, setupMessage )
    import Distribution.Simple.Setup ( Flag(..), SDistFlags(..)
                                     , fromFlag, flagToMaybe)
    import Distribution.Simple.PreProcess ( PPSuffixHandler, ppSuffixes
                                          , preprocessComponent )
    import Distribution.Simple.LocalBuildInfo
             ( LocalBuildInfo(..), withAllComponentsInBuildOrder )
    import Distribution.Simple.BuildPaths ( autogenModuleName )
    import Distribution.Simple.Program ( defaultProgramConfiguration, requireProgram,
                                         runProgram, programProperties, tarProgram )
    import Distribution.Text
             ( display )

    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 Distribution.Verbosity (Verbosity)
    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.
        withLib $ \Library { exposedModules = modules, libBuildInfo = libBi } ->
         allSourcesBuildInfo libBi pps modules

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

        -- Test suites sources.
      , fmap concat
        . withTest $ \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
        . withBenchmark $ \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.
      , withLib $ \ 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:
        withLib       action = maybe (return []) action (library pkg_descr)
        withExe       action = mapM action (executables pkg_descr)
        withTest      action = mapM action (testSuites pkg_descr)
        withBenchmark 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 <- sequence
        [ let file = ModuleName.toFilePath module_
          in findFileWithExtension suffixes searchDirs file
             >>= maybe (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
        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 _                         = 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) }