{- git-annex command
 -
 - Copyright 2012-2013 Joey Hess <id@joeyh.name>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

module Command.Import where

import Command
import qualified Git
import qualified Annex
import qualified Command.Add
import Utility.CopyFile
import Backend
import Remote
import Types.KeySource
import Annex.CheckIgnore
import Annex.NumCopies
import Annex.FileMatcher

cmd :: Command
cmd = withGlobalOptions (jobsOption : jsonOption : fileMatchingOptions) $ notBareRepo $
	command "import" SectionCommon 
		"move and add files from outside git working copy"
		paramPaths (seek <$$> optParser)

data DuplicateMode = Default | Duplicate | DeDuplicate | CleanDuplicates | SkipDuplicates
	deriving (Eq)

data ImportOptions = ImportOptions
	{ importFiles :: CmdParams
	, duplicateMode :: DuplicateMode
	}

optParser :: CmdParamsDesc -> Parser ImportOptions
optParser desc = ImportOptions
	<$> cmdParams desc
	<*> (fromMaybe Default <$> optional duplicateModeParser)

duplicateModeParser :: Parser DuplicateMode
duplicateModeParser = 
	flag' Duplicate
		( long "duplicate" 
		<> help "do not delete source files"
		)
	<|> flag' DeDuplicate
		( long "deduplicate"
		<> help "delete source files whose content was imported before"
		)
	<|> flag' CleanDuplicates
		( long "clean-duplicates"
		<> help "delete duplicate source files (import nothing)"
		)
	<|> flag' SkipDuplicates
		( long "skip-duplicates"
		<> help "import only new files"
		)

seek :: ImportOptions -> CommandSeek
seek o = allowConcurrentOutput $ do
	repopath <- liftIO . absPath =<< fromRepo Git.repoPath
	inrepops <- liftIO $ filter (dirContains repopath) <$> mapM absPath (importFiles o)
	unless (null inrepops) $ do
		giveup $ "cannot import files from inside the working tree (use git annex add instead): " ++ unwords inrepops
	largematcher <- largeFilesMatcher
	withPathContents (start largematcher (duplicateMode o)) (importFiles o)

start :: GetFileMatcher -> DuplicateMode -> (FilePath, FilePath) -> CommandStart
start largematcher mode (srcfile, destfile) =
	ifM (liftIO $ isRegularFile <$> getSymbolicLinkStatus srcfile)
		( do
			ma <- pickaction
			case ma of
				Nothing -> stop
				Just a -> do
					showStart "import" destfile
					next a
		, stop
		)
  where
	deletedup k = do
		showNote $ "duplicate of " ++ key2file k
		verifyExisting k destfile
			( do
				liftIO $ removeFile srcfile
				next $ return True
			, do
				warning "Could not verify that the content is still present in the annex; not removing from the import location."
				stop
			)
	importfile = checkdestdir $ do
		ignored <- not <$> Annex.getState Annex.force <&&> checkIgnored destfile
		if ignored
			then do
				warning $ "not importing " ++ destfile ++ " which is .gitignored (use --force to override)"
				stop
			else do
				existing <- liftIO (catchMaybeIO $ getSymbolicLinkStatus destfile)
				case existing of
					Nothing -> importfilechecked
					Just s
						| isDirectory s -> notoverwriting "(is a directory)"
						| isSymbolicLink s -> notoverwriting "(is a symlink)"
						| otherwise -> ifM (Annex.getState Annex.force)
							( do
								liftIO $ nukeFile destfile
								importfilechecked
							, notoverwriting "(use --force to override, or a duplication option such as --deduplicate to clean up)"
							)
	checkdestdir cont = do
		let destdir = parentDir destfile
		existing <- liftIO (catchMaybeIO $ getSymbolicLinkStatus destdir)
		case existing of
			Nothing -> cont
			Just s
				| isDirectory s -> cont
				| otherwise -> do
					warning $ "not importing " ++ destfile ++ " because " ++ destdir ++ " is not a directory"
					stop

	importfilechecked = do
		liftIO $ createDirectoryIfMissing True (parentDir destfile)
		liftIO $ if mode == Duplicate || mode == SkipDuplicates
			then void $ copyFileExternal CopyAllMetaData srcfile destfile
			else moveFile srcfile destfile
		ifM (checkFileMatcher largematcher destfile)
			( Command.Add.perform destfile
			, next $ Command.Add.addSmall destfile 
			)
	notoverwriting why = do
		warning $ "not overwriting existing " ++ destfile ++ " " ++ why
		stop
	checkdup dupa notdupa = do
		backend <- chooseBackend destfile
		let ks = KeySource srcfile srcfile Nothing
		v <- genKey ks backend
		case v of
			Just (k, _) -> ifM (not . null <$> keyLocations k)
				( return (maybe Nothing (\a -> Just (a k)) dupa)
				, return notdupa
				)
			_ -> return notdupa
	pickaction = case mode of
		DeDuplicate -> checkdup (Just deletedup) (Just importfile)
		CleanDuplicates -> checkdup (Just deletedup) Nothing
		SkipDuplicates -> checkdup Nothing (Just importfile)
		_ -> return (Just importfile)

verifyExisting :: Key -> FilePath -> (CommandPerform, CommandPerform) -> CommandPerform
verifyExisting key destfile (yes, no) = do
	-- Look up the numcopies setting for the file that it would be
	-- imported to, if it were imported.
	need <- getFileNumCopies destfile

	(tocheck, preverified) <- verifiableCopies key []
	verifyEnoughCopiesToDrop [] key Nothing need [] preverified tocheck
		(const yes) no
