{- git-annex file matching
 -
 - Copyright 2012-2024 Joey Hess <id@joeyh.name>
 -
 - Licensed under the GNU AGPL version 3 or higher.
 -}

{-# LANGUAGE CPP #-}

module Annex.FileMatcher (
	GetFileMatcher,
	checkFileMatcher,
	checkFileMatcher',
	checkMatcher,
	checkMatcher',
	makeMatcher,
	matchAll,
	PreferredContentData(..),
	preferredContentTokens,
	preferredContentParser,
	checkPreferredContentExpression,
	ParseToken,
	parsedToMatcher,
	mkMatchExpressionParser,
	largeFilesMatcher,
	AddUnlockedMatcher,
	addUnlockedMatcher,
	checkAddUnlockedMatcher,
	LimitBy(..),
	module Types.FileMatcher
) where

import qualified Data.Map as M

import Annex.Common
import Limit
import Utility.Matcher
import Types.Group
import Types.FileMatcher
import Types.GitConfig
import Config.GitConfig
import Annex.SpecialRemote.Config (preferreddirField)
import Git.FilePath
import Types.Remote (RemoteConfig)
import Types.ProposedAccepted
import Types.StandardGroups
import Logs.Group
import Annex.CheckAttr
import Annex.RepoSize.LiveUpdate
import qualified Git.Config
#ifdef WITH_MAGICMIME
import Annex.Magic
#endif

import Data.Either
import qualified Data.Set as S
import Control.Monad.Writer

type GetFileMatcher = RawFilePath -> Annex (FileMatcher Annex)

checkFileMatcher :: LiveUpdate -> GetFileMatcher -> RawFilePath -> Annex Bool
checkFileMatcher lu getmatcher file =
	checkFileMatcher' lu getmatcher file (return True)

-- | Allows running an action when no matcher is configured for the file.
checkFileMatcher' :: LiveUpdate -> GetFileMatcher -> RawFilePath -> Annex Bool -> Annex Bool
checkFileMatcher' lu getmatcher file notconfigured = do
	matcher <- getmatcher file
	checkMatcher matcher Nothing afile lu S.empty notconfigured d
  where
	afile = AssociatedFile (Just file)
	-- checkMatcher will never use this, because afile is provided.
	d = return True

checkMatcher :: FileMatcher Annex -> Maybe Key -> AssociatedFile -> LiveUpdate -> AssumeNotPresent -> Annex Bool -> Annex Bool -> Annex Bool
checkMatcher matcher mkey afile lu notpresent notconfigured d
	| isEmpty (fst matcher) = notconfigured
	| otherwise = case (mkey, afile) of
		(_, AssociatedFile (Just file)) ->
			go =<< fileMatchInfo file mkey
		(Just key, AssociatedFile Nothing) ->
			let i = ProvidedInfo
				{ providedFilePath = Nothing
				, providedKey = Just key
				, providedFileSize = Nothing
				, providedMimeType = Nothing
				, providedMimeEncoding = Nothing
				, providedLinkType = Nothing
				}
			in go (MatchingInfo i)
		(Nothing, _) -> d
  where
	go mi = checkMatcher' matcher mi lu notpresent

checkMatcher' :: FileMatcher Annex -> MatchInfo -> LiveUpdate -> AssumeNotPresent -> Annex Bool
checkMatcher' (matcher, (MatcherDesc matcherdesc)) mi lu notpresent =
	checkLiveUpdate lu matcher go
  where
	go = do
		(matches, desc) <- runWriterT $ matchMrun' matcher $ \op ->
			matchAction op lu notpresent mi
		let descmsg = UnquotedString <$>
				describeMatchResult
					(\o -> matchDesc o . Just) desc
					((if matches then "matches " else "does not match ") ++ matcherdesc ++ ": ")
		let unstablenegated = filter matchNegationUnstable (findNegated matcher)
		if null unstablenegated
			then do
				explain (mkActionItem mi) descmsg
				return matches
			else do
				let s = concat 
					[ ", but that expression is not stable due to negated use of "
					, unwords $ nub $ 
						map (fromMatchDesc . flip matchDesc Nothing)
							unstablenegated
					, ", so will not be used"
					]
				explain (mkActionItem mi) $ Just $
					fromMaybe mempty descmsg <> UnquotedString s
				return False

fileMatchInfo :: RawFilePath -> Maybe Key -> Annex MatchInfo
fileMatchInfo file mkey = do
	matchfile <- getTopFilePath <$> inRepo (toTopFilePath file)
	return $ MatchingFile FileInfo
		{ matchFile = matchfile
		, contentFile = file
		, matchKey = mkey
		}

matchAll :: Matcher (MatchFiles Annex)
matchAll = generate []

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

data ParseToken t
	= SimpleToken String (ParseResult t)
	| ValueToken String (String -> ParseResult t)

type ParseResult t = Either String (Token t)

parseToken :: [ParseToken t] -> String -> ParseResult t
parseToken l t = case syntaxToken t of
	Right st -> Right st
	Left _ -> go l
  where
	go [] = Left $ "near " ++ show t
	go (SimpleToken s r : _) | s == t = r
	go (ValueToken s mkr : _) | s == k = mkr v
	go (_ : ps) = go ps
	(k, v) = separate (== '=') t

{- 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` "()")

commonTokens :: LimitBy -> [ParseToken (MatchFiles Annex)]
commonTokens lb =
	[ SimpleToken "anything" (simply limitAnything)
	, SimpleToken "nothing" (simply limitNothing)
	, ValueToken "include" (usev limitInclude)
	, ValueToken "exclude" (usev limitExclude)
	, ValueToken "largerthan" (usev $ limitSize lb "largerthan" (>))
	, ValueToken "smallerthan" (usev $ limitSize lb "smallerthan" (<))
	, SimpleToken "unused" (simply limitUnused)
	]

data PreferredContentData = PCD
	{ matchStandard :: Either String (Matcher (MatchFiles Annex))
	, matchGroupWanted :: Either String (Matcher (MatchFiles Annex))
	, getGroupMap :: Annex GroupMap
	, configMap :: M.Map UUID RemoteConfig
	, repoUUID :: Maybe UUID
	}

preferredContentTokens :: PreferredContentData -> [ParseToken (MatchFiles Annex)]
preferredContentTokens pcd =
	[ SimpleToken "standard" (call "standard" $ matchStandard pcd)
	, SimpleToken "groupwanted" (call "groupwanted" $ matchGroupWanted pcd)
	, SimpleToken "inpreferreddir" (simply $ limitInDir preferreddir "inpreferreddir")
	, SimpleToken "present" (simply $ limitPresent $ repoUUID pcd)
	, SimpleToken "securehash" (simply limitSecureHash)
	, ValueToken "copies" (usev limitCopies)
	, ValueToken "lackingcopies" (usev $ limitLackingCopies "lackingcopies" False)
	, ValueToken "approxlackingcopies" (usev $ limitLackingCopies "approxlackingcopies" True)
	, ValueToken "inbackend" (usev limitInBackend)
	, ValueToken "metadata" (usev limitMetaData)
	, ValueToken "inallgroup" (usev $ limitInAllGroup $ getGroupMap pcd)
	, ValueToken "onlyingroup" (usev $ limitOnlyInGroup $ getGroupMap pcd)
	, ValueToken "balanced" (usev $ limitBalanced (repoUUID pcd) (getGroupMap pcd))
	, ValueToken "fullybalanced" (usev $ limitFullyBalanced (repoUUID pcd) (getGroupMap pcd))
	, ValueToken "sizebalanced" (usev $ limitSizeBalanced (repoUUID pcd) (getGroupMap pcd))
	, ValueToken "fullysizebalanced" (usev $ limitFullySizeBalanced (repoUUID pcd) (getGroupMap pcd))
	] ++ commonTokens LimitAnnexFiles
  where
	preferreddir = maybe "public" fromProposedAccepted $
		M.lookup preferreddirField =<< (`M.lookup` configMap pcd) =<< repoUUID pcd

preferredContentParser :: [ParseToken (MatchFiles Annex)] -> String -> [ParseResult (MatchFiles Annex)]
preferredContentParser tokens = map (parseToken tokens) . tokenizeMatcher

mkMatchExpressionParser :: Annex (String -> [ParseResult (MatchFiles Annex)])
mkMatchExpressionParser = do
#ifdef WITH_MAGICMIME
	magicmime <- liftIO initMagicMime
	let mimer n f = ValueToken n (usev $ f magicmime)
#else
	let mimer n = ValueToken n $ 
		const $ Left $ "\""++n++"\" not supported; not built with MagicMime support"
#endif
	let parse = parseToken $
		commonTokens LimitDiskFiles ++
#ifdef WITH_MAGICMIME
		[ mimer "mimetype" $
			matchMagic "mimetype" getMagicMimeType providedMimeType userProvidedMimeType
		, mimer "mimeencoding" $
			matchMagic "mimeencoding" getMagicMimeEncoding providedMimeEncoding userProvidedMimeEncoding
		]
#else
		[ mimer "mimetype"
		, mimer "mimeencoding"
		]
#endif
	return $ map parse . tokenizeMatcher

{- Generates a matcher for files large enough (or meeting other criteria)
 - to be added to the annex, rather than directly to git.
 -
 - annex.largefiles is configured in git config, or git attributes,
 - or global git-annex config, in that order.
 -}
largeFilesMatcher :: Annex GetFileMatcher
largeFilesMatcher = go =<< getGitConfigVal' annexLargeFiles
  where
	matcherdesc = MatcherDesc "annex.largefiles"
	go (HasGitConfig (Just expr)) = do
		matcher <- mkmatcher expr "git config"
		return $ const $ return matcher
	go v = return $ \file -> do
		expr <- checkAttr "annex.largefiles" file
		if null expr
			then case v of
				HasGlobalConfig (Just expr') ->
					mkmatcher expr' "git-annex config"
				_ -> return (matchAll, matcherdesc)
			else mkmatcher expr "gitattributes"

	mkmatcher expr cfgfrom = do
		parser <- mkMatchExpressionParser
		either (badexpr cfgfrom) return $ parsedToMatcher matcherdesc $ parser expr

	badexpr cfgfrom e = giveup $ "bad annex.largefiles configuration in " ++ cfgfrom ++ ": " ++ e

newtype AddUnlockedMatcher = AddUnlockedMatcher (FileMatcher Annex)

addUnlockedMatcher :: Annex AddUnlockedMatcher
addUnlockedMatcher = AddUnlockedMatcher <$>
	(go =<< getGitConfigVal' annexAddUnlocked)
  where
	go (HasGitConfig (Just expr)) = mkmatcher expr "git config"
	go (HasGlobalConfig (Just expr)) = mkmatcher expr "git annex config"
	go _ = matchalways False

	matcherdesc = MatcherDesc "annex.addunlocked"

	mkmatcher :: String -> String -> Annex (FileMatcher Annex)
	mkmatcher expr cfgfrom = case Git.Config.isTrueFalse expr of
		Just b -> matchalways b
		Nothing -> do
			parser <- mkMatchExpressionParser
			either (badexpr cfgfrom) return $ parsedToMatcher matcherdesc $ parser expr

	badexpr cfgfrom e = giveup $ "bad annex.addunlocked configuration in " ++ cfgfrom ++ ": " ++ e

	matchalways True = return (MOp limitAnything, matcherdesc)
	matchalways False = return (MOp limitNothing, matcherdesc)

checkAddUnlockedMatcher :: LiveUpdate -> AddUnlockedMatcher -> MatchInfo -> Annex Bool
checkAddUnlockedMatcher lu (AddUnlockedMatcher matcher) mi = 
	checkMatcher' matcher mi lu S.empty

simply :: MatchFiles Annex -> ParseResult (MatchFiles Annex)
simply = Right . Operation

usev :: MkLimit Annex -> String -> ParseResult (MatchFiles Annex)
usev a v = Operation <$> a v

call :: String -> Either String (Matcher (MatchFiles Annex)) -> ParseResult (MatchFiles Annex)
call desc (Right sub) = Right $ Operation $ MatchFiles
	{ matchAction = \lu notpresent mi ->
		matchMrun sub $ \o -> matchAction o lu notpresent mi
	, matchNeedsFileName = any matchNeedsFileName sub
	, matchNeedsFileContent = any matchNeedsFileContent sub
	, matchNeedsKey = any matchNeedsKey sub
	, matchNeedsLocationLog = any matchNeedsLocationLog sub
	, matchNeedsLiveRepoSize = any matchNeedsLiveRepoSize sub
	, matchNegationUnstable = any matchNegationUnstable sub
	, matchDesc = matchDescSimple desc
	}
call _ (Left err) = Left err

makeMatcher
	:: GroupMap
	-> M.Map UUID RemoteConfig
	-> M.Map Group PreferredContentExpression
	-> UUID
	-> (Matcher (MatchFiles Annex) -> Matcher (MatchFiles Annex))
	-> (PreferredContentData -> [ParseToken (MatchFiles Annex)])
	-> Either String (Matcher (MatchFiles Annex))
	-> PreferredContentExpression
	-> Either String (Matcher (MatchFiles Annex))
makeMatcher groupmap configmap groupwantedmap u matcherf mktokens unknownmatcher = go True True
  where
	go expandstandard expandgroupwanted expr
		| null (lefts tokens) = Right $ matcherf $ generate $ rights tokens
		| otherwise = Left $ unwords $ lefts tokens
	  where
		tokens = preferredContentParser (mktokens pcd) expr
		pcd = PCD
			{ matchStandard = matchstandard
			, matchGroupWanted = matchgroupwanted
			, getGroupMap = pure groupmap
			, configMap = configmap
			, repoUUID = Just u
			}
		matchstandard
			| expandstandard = maybe unknownmatcher (go False False)
				(standardPreferredContent <$> getStandardGroup mygroups)
			| otherwise = unknownmatcher
		matchgroupwanted
			| expandgroupwanted = maybe unknownmatcher (go True False)
				(groupwanted mygroups)
			| otherwise = unknownmatcher
		mygroups = fromMaybe S.empty (u `M.lookup` groupsByUUID groupmap)
		groupwanted s = case M.elems $ M.filterWithKey (\k _ -> S.member k s) groupwantedmap of
			[pc] -> Just pc
			_ -> Nothing

{- Checks if an expression can be parsed, if not returns Just error -}
checkPreferredContentExpression :: PreferredContentExpression -> Maybe String
checkPreferredContentExpression expr = 
	case parsedToMatcher (MatcherDesc mempty) tokens of
		Left e -> Just e
		Right _ -> Nothing
  where
	tokens = preferredContentParser (preferredContentTokens pcd) expr
	pcd = PCD
		{ matchStandard = Right matchAll
		, matchGroupWanted = Right matchAll
		, getGroupMap = pure emptyGroupMap
		, configMap = M.empty
		, repoUUID = Nothing
		}