{- git-annex file matching
 -
 - Copyright 2012-2014 Joey Hess <joey@kitenet.net>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

module Annex.FileMatcher where

import qualified Data.Map as M

import Common.Annex
import Limit
import Utility.Matcher
import Types.Group
import Types.Limit
import Logs.Group
import Logs.Remote
import Annex.UUID
import qualified Annex
import Types.FileMatcher
import Git.FilePath
import Types.Remote (RemoteConfig)

import Data.Either
import qualified Data.Set as S

type FileMatcher = Matcher MatchFiles

checkFileMatcher :: FileMatcher -> FilePath -> Annex Bool
checkFileMatcher matcher file = checkMatcher matcher Nothing (Just file) S.empty True

checkMatcher :: FileMatcher -> Maybe Key -> AssociatedFile -> AssumeNotPresent -> Bool -> Annex Bool
checkMatcher matcher mkey afile notpresent def
	| isEmpty matcher = return def
	| otherwise = case (mkey, afile) of
		(_, Just file) -> go =<< fileMatchInfo file
		(Just key, _) -> go (MatchingKey key)
		_ -> return def
  where
	go mi = matchMrun matcher $ \a -> a notpresent mi

fileMatchInfo :: FilePath -> Annex MatchInfo
fileMatchInfo file = do
	matchfile <- getTopFilePath <$> inRepo (toTopFilePath file)
	return $ MatchingFile $ FileInfo
		{ matchFile = matchfile
		, relFile = file
		}

matchAll :: FileMatcher
matchAll = generate []

parsedToMatcher :: [Either String (Token MatchFiles)] -> Either String FileMatcher
parsedToMatcher parsed = case partitionEithers parsed of
	([], vs) -> Right $ generate vs
	(es, _) -> Left $ unwords $ map ("Parse failure: " ++) es

exprParser :: GroupMap -> M.Map UUID RemoteConfig -> Maybe UUID -> String -> [Either String (Token MatchFiles)]
exprParser groupmap configmap mu expr =
	map parse $ tokenizeMatcher expr
  where
	parse = parseToken 
		(limitPresent mu)
		(limitInDir preferreddir)
		groupmap
	preferreddir = fromMaybe "public" $
		M.lookup "preferreddir" =<< (`M.lookup` configmap) =<< mu

parseToken :: MkLimit -> MkLimit -> GroupMap -> String -> Either String (Token MatchFiles)
parseToken checkpresent checkpreferreddir groupmap t
	| t `elem` tokens = Right $ token t
	| t == "present" = use checkpresent
	| t == "inpreferreddir" = use checkpreferreddir
	| t == "unused" = Right (Operation limitUnused)
	| otherwise = maybe (Left $ "near " ++ show t) use $ M.lookup k $
		M.fromList
			[ ("include", limitInclude)
			, ("exclude", limitExclude)
			, ("copies", limitCopies)
			, ("lackingcopies", limitLackingCopies False)
			, ("approxlackingcopies", limitLackingCopies True)
			, ("inbackend", limitInBackend)
			, ("largerthan", limitSize (>))
			, ("smallerthan", limitSize (<))
			, ("inallgroup", limitInAllGroup groupmap)
			]
  where
	(k, v) = separate (== '=') t
	use a = Operation <$> a v

{- This is really dumb tokenization; there's no support for quoted values.
 - Open and close parens are always treated as standalone tokens;
 - otherwise tokens must be separated by whitespace. -}
tokenizeMatcher :: String -> [String]
tokenizeMatcher = filter (not . null ) . concatMap splitparens . words
  where
	splitparens = segmentDelim (`elem` "()")

{- Generates a matcher for files large enough (or meeting other criteria)
 - to be added to the annex, rather than directly to git. -}
largeFilesMatcher :: Annex FileMatcher
largeFilesMatcher = go =<< annexLargeFiles <$> Annex.getGitConfig
  where
  	go Nothing = return matchAll
	go (Just expr) = do
		gm <- groupMap
		rc <- readRemoteLog
		u <- getUUID
		either badexpr return $
			parsedToMatcher $ exprParser gm rc (Just u) expr
	badexpr e = error $ "bad annex.largefiles configuration: " ++ e