{- git-annex command seeking
 - 
 - These functions find appropriate files or other things based on
 - the values a user passes to a command, and prepare actions operating
 - on them.
 -
 - Copyright 2010-2014 Joey Hess <joey@kitenet.net>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

module CmdLine.Seek where

import System.PosixCompat.Files

import Common.Annex
import Types.Command
import Types.Key
import Types.FileMatcher
import qualified Annex
import qualified Git
import qualified Git.Command
import qualified Git.LsFiles as LsFiles
import qualified Limit
import CmdLine.Option
import Logs.Location
import Logs.Unused
import Annex.CatFile
import RunCommand

withFilesInGit :: (FilePath -> CommandStart) -> CommandSeek
withFilesInGit a params = seekActions $ prepFiltered a $
	seekHelper LsFiles.inRepo params

withFilesNotInGit :: (FilePath -> CommandStart) -> CommandSeek
withFilesNotInGit a params = do
	{- dotfiles are not acted on unless explicitly listed -}
	files <- filter (not . dotfile) <$>
		seekunless (null ps && not (null params)) ps
	dotfiles <- seekunless (null dotps) dotps
	seekActions $ prepFiltered a $
		return $ concat $ segmentPaths params (files++dotfiles)
  where
	(dotps, ps) = partition dotfile params
	seekunless True _ = return []
	seekunless _ l = do
		force <- Annex.getState Annex.force
		g <- gitRepo
		liftIO $ Git.Command.leaveZombie <$> LsFiles.notInRepo force l g

withPathContents :: ((FilePath, FilePath) -> CommandStart) -> CommandSeek
withPathContents a params = seekActions $ 
	map a . concat <$> liftIO (mapM get params)
  where
	get p = ifM (isDirectory <$> getFileStatus p)
		( map (\f -> (f, makeRelative (parentDir p) f))
			<$> dirContentsRecursiveSkipping (".git" `isSuffixOf`) True p
		, return [(p, takeFileName p)]
		)

withWords :: ([String] -> CommandStart) -> CommandSeek
withWords a params = seekActions $ return [a params]

withStrings :: (String -> CommandStart) -> CommandSeek
withStrings a params = seekActions $ return $ map a params

withPairs :: ((String, String) -> CommandStart) -> CommandSeek
withPairs a params = seekActions $ return $ map a $ pairs [] params
  where
	pairs c [] = reverse c
	pairs c (x:y:xs) = pairs ((x,y):c) xs
	pairs _ _ = error "expected pairs"

withFilesToBeCommitted :: (String -> CommandStart) -> CommandSeek
withFilesToBeCommitted a params = seekActions $ prepFiltered a $
	seekHelper LsFiles.stagedNotDeleted params

withFilesUnlocked :: (FilePath -> CommandStart) -> CommandSeek
withFilesUnlocked = withFilesUnlocked' LsFiles.typeChanged

withFilesUnlockedToBeCommitted :: (FilePath -> CommandStart) -> CommandSeek
withFilesUnlockedToBeCommitted = withFilesUnlocked' LsFiles.typeChangedStaged

{- Unlocked files have changed type from a symlink to a regular file.
 -
 - Furthermore, unlocked files used to be a git-annex symlink,
 - not some other sort of symlink.
 -}
withFilesUnlocked' :: ([FilePath] -> Git.Repo -> IO ([FilePath], IO Bool)) -> (FilePath -> CommandStart) -> CommandSeek
withFilesUnlocked' typechanged a params = seekActions $
	prepFiltered a unlockedfiles
  where
  	check f = liftIO (notSymlink f) <&&> 
		(isJust <$> catKeyFile f <||> isJust <$> catKeyFileHEAD f)
	unlockedfiles = filterM check =<< seekHelper typechanged params

{- Finds files that may be modified. -}
withFilesMaybeModified :: (FilePath -> CommandStart) -> CommandSeek
withFilesMaybeModified a params = seekActions $
	prepFiltered a $ seekHelper LsFiles.modified params

withKeys :: (Key -> CommandStart) -> CommandSeek
withKeys a params = seekActions $ return $ map (a . parse) params
  where
	parse p = fromMaybe (error "bad key") $ file2key p

{- Gets the value of a field options, which is fed into
 - a conversion function.
 -}
getOptionField :: Option -> (Maybe String -> Annex a) -> Annex a
getOptionField option converter = converter <=< Annex.getField $ optionName option

getOptionFlag :: Option -> Annex Bool
getOptionFlag option = Annex.getFlag (optionName option)

withNothing :: CommandStart -> CommandSeek
withNothing a [] = seekActions $ return [a]
withNothing _ _ = error "This command takes no parameters."

{- If --all is specified, or in a bare repo, runs an action on all
 - known keys.
 -
 - If --unused is specified, runs an action on all keys found by
 - the last git annex unused scan.
 -
 - If --key is specified, operates only on that key.
 -
 - Otherwise, fall back to a regular CommandSeek action on
 - whatever params were passed. -}
withKeyOptions :: (Key -> CommandStart) -> CommandSeek -> CommandSeek
withKeyOptions keyop fallbackop params = do
	bare <- fromRepo Git.repoIsLocalBare
	allkeys <- Annex.getFlag "all"
	unused <- Annex.getFlag "unused"
	specifickey <- Annex.getField "key"
	auto <- Annex.getState Annex.auto
	when (auto && bare) $
		error "Cannot use --auto in a bare repository"
	case	(allkeys, unused, null params, specifickey) of
		(False  , False , True       , Nothing)
			| bare -> go auto loggedKeys
			| otherwise -> fallbackop params
		(False  , False , _          , Nothing) -> fallbackop params
		(True   , False , True       , Nothing) -> go auto loggedKeys
		(False  , True  , True       , Nothing) -> go auto unusedKeys'
		(False  , False , True       , Just ks) -> case file2key ks of
			Nothing -> error "Invalid key"
			Just k -> go auto $ return [k]
		_ -> error "Can only specify one of file names, --all, --unused, or --key"
  where
  	go True _ = error "Cannot use --auto with --all or --unused or --key"
	go False a = do
		matcher <- Limit.getMatcher
		seekActions $ map (process matcher) <$> a
	process matcher k = ifM (matcher $ MatchingKey k)
		( keyop k , return Nothing)

prepFiltered :: (FilePath -> CommandStart) -> Annex [FilePath] -> Annex [CommandStart]
prepFiltered a fs = do
	matcher <- Limit.getMatcher
	map (process matcher) <$> fs
  where
	process matcher f = ifM (matcher $ MatchingFile $ FileInfo f f)
		( a f , return Nothing )

seekActions :: Annex [CommandStart] -> Annex ()
seekActions gen = do
	as <- gen
	mapM_ commandAction as

seekHelper :: ([FilePath] -> Git.Repo -> IO ([FilePath], IO Bool)) -> [FilePath] -> Annex [FilePath]
seekHelper a params = do
	ll <- inRepo $ \g ->
		runSegmentPaths (\fs -> Git.Command.leaveZombie <$> a fs g) params
	{- Show warnings only for files/directories that do not exist. -}
	forM_ (map fst $ filter (null . snd) $ zip params ll) $ \p ->
		unlessM (isJust <$> liftIO (catchMaybeIO $ getSymbolicLinkStatus p)) $
			fileNotFound p
	return $ concat ll

notSymlink :: FilePath -> IO Bool
notSymlink f = liftIO $ not . isSymbolicLink <$> getSymbolicLinkStatus f