From 0e9a72b35640c24e3f0de8255326b26994b06d2d Mon Sep 17 00:00:00 2001
From: Joey Hess <joey@kitenet.net>
Date: Thu, 13 Feb 2014 01:49:38 -0400
Subject: [PATCH] metacata command can now operate on many files at once

---
 Annex.hs            |  3 +++
 Command/MetaData.hs | 60 ++++++++++++++++-----------------------------
 Types/MetaData.hs   | 36 +++++++++++++++++++++++++--
 doc/git-annex.mdwn  | 14 +++++------
 4 files changed, 65 insertions(+), 48 deletions(-)

diff --git a/Annex.hs b/Annex.hs
index 87a06615e6..f3f2a91779 100644
--- a/Annex.hs
+++ b/Annex.hs
@@ -58,6 +58,7 @@ import Types.UUID
 import Types.FileMatcher
 import Types.NumCopies
 import Types.LockPool
+import Types.MetaData
 import qualified Utility.Matcher
 import qualified Data.Map as M
 import qualified Data.Set as S
@@ -109,6 +110,7 @@ data AnnexState = AnnexState
 	, lockpool :: LockPool
 	, flags :: M.Map String Bool
 	, fields :: M.Map String String
+	, modmeta :: [ModMeta]
 	, cleanup :: M.Map String (Annex ())
 	, inodeschanged :: Maybe Bool
 	, useragent :: Maybe String
@@ -146,6 +148,7 @@ newState c r = AnnexState
 	, lockpool = M.empty
 	, flags = M.empty
 	, fields = M.empty
+	, modmeta = []
 	, cleanup = M.empty
 	, inodeschanged = Nothing
 	, useragent = Nothing
diff --git a/Command/MetaData.hs b/Command/MetaData.hs
index d4d3f880cb..a645b274a3 100644
--- a/Command/MetaData.hs
+++ b/Command/MetaData.hs
@@ -8,6 +8,7 @@
 module Command.MetaData where
 
 import Common.Annex
+import qualified Annex
 import Command
 import Logs.MetaData
 import Types.MetaData
@@ -15,27 +16,32 @@ import Types.MetaData
 import qualified Data.Set as S
 
 def :: [Command]
-def = [command "metadata" (paramPair paramFile (paramRepeating "FIELD[+-]=VALUE")) seek
+def = [withOptions [setOption] $ command "metadata" paramPaths seek
 	SectionUtility "sets metadata of a file"]
 
-seek :: CommandSeek
-seek = withWords start
-
-start :: [String] -> CommandStart
-start (file:settings) = ifAnnexed file
-	go
-	(error $ "not an annexed file, so cannot add metadata: " ++ file)
+setOption :: Option
+setOption = Option ['s'] ["set"] (ReqArg mkmod "field[+-]=value") "set metadata"
   where
-	go (k, _b) = do
-		showStart "metadata" file
-		next $ perform k (map parse settings)
-start _ = error "specify a file and the metadata to set"
+	mkmod p = case parseModMeta p of
+		Left e -> error e
+		Right modmeta -> Annex.changeState $
+			\s -> s { Annex.modmeta = modmeta:Annex.modmeta s }
 
-perform :: Key -> [Action] -> CommandPerform
+seek :: CommandSeek
+seek ps = do
+	modmeta <- Annex.getState Annex.modmeta
+	withFilesInGit (whenAnnexed $ start modmeta) ps
+
+start :: [ModMeta] -> FilePath -> (Key, Backend) -> CommandStart
+start ms file (k, _) = do
+	showStart "metadata" file
+	next $ perform k ms
+
+perform :: Key -> [ModMeta] -> CommandPerform
 perform k [] = next $ cleanup k
-perform k as = do
+perform k ms = do
 	oldm <- getCurrentMetaData k
-	let m = foldr (apply oldm) newMetaData as
+	let m = foldl' unionMetaData newMetaData $ map (modMeta oldm) ms
 	addMetaData k m
 	next $ cleanup k
 	
@@ -46,27 +52,3 @@ cleanup k = do
 	return True
   where
 	showmeta (f, vs) = map (\v -> fromMetaField f ++ "=" ++ fromMetaValue v) $ S.toList vs
-
-data Action
-	= AddMeta MetaField MetaValue
-	| DelMeta MetaField MetaValue
-	| SetMeta MetaField MetaValue
-
-parse :: String -> Action
-parse p = case lastMaybe f of
-	Just '+' -> AddMeta (mkf f') v
-	Just '-' -> DelMeta (mkf f') v
-	_ -> SetMeta (mkf f) v
-  where
-	(f, sv) = separate (== '=') p
-	f' = beginning f
-	v = toMetaValue sv
-	mkf fld = fromMaybe (badfield fld) (toMetaField fld)
-	badfield fld = error $ "Illegal metadata field name, \"" ++ fld ++ "\""
-
-apply :: MetaData -> Action -> MetaData -> MetaData
-apply _ (AddMeta f v) m = updateMetaData f v m
-apply _ (DelMeta f oldv) m = updateMetaData f (unsetMetaValue oldv) m
-apply oldm (SetMeta f v) m = updateMetaData f v $
-	foldr (updateMetaData f) m $
-		map unsetMetaValue $ S.toList $ currentMetaDataValues f oldm
diff --git a/Types/MetaData.hs b/Types/MetaData.hs
index a3fe584833..cd694e86a2 100644
--- a/Types/MetaData.hs
+++ b/Types/MetaData.hs
@@ -12,6 +12,8 @@ module Types.MetaData (
 	MetaField,
 	MetaValue,
 	CurrentlySet(..),
+	serialize,
+	deserialize,
 	MetaSerializable,
 	toMetaField,
 	fromMetaField,
@@ -27,8 +29,9 @@ module Types.MetaData (
 	currentMetaData,
 	currentMetaDataValues,
 	getAllMetaData,
-	serialize,
-	deserialize,
+	ModMeta(..),
+	modMeta,
+	parseModMeta,
 	prop_metadata_sane,
 	prop_metadata_serialize
 ) where
@@ -180,6 +183,35 @@ removeEmptyFields (MetaData m) = MetaData $ M.filter (not . S.null) m
 getAllMetaData :: MetaField -> MetaData -> S.Set MetaValue
 getAllMetaData f (MetaData m) = fromMaybe S.empty (M.lookup f m)
 
+{- Ways that existing metadata can be modified -}
+data ModMeta
+	= AddMeta MetaField MetaValue
+	| DelMeta MetaField MetaValue
+	| SetMeta MetaField MetaValue -- removes any existing values
+
+{- Applies a ModMeta, generating the new MetaData.
+ - Note that the new MetaData does not include all the 
+ - values set in the input metadata. It only contains changed values. -}
+modMeta :: MetaData -> ModMeta -> MetaData
+modMeta _ (AddMeta f v) = updateMetaData f v newMetaData
+modMeta _ (DelMeta f oldv) = updateMetaData f (unsetMetaValue oldv) newMetaData
+modMeta m (SetMeta f v) = updateMetaData f v $
+	foldr (updateMetaData f) newMetaData $
+		map unsetMetaValue $ S.toList $ currentMetaDataValues f m
+
+{- Parses field=value, field+=value, field-=value -}
+parseModMeta :: String -> Either String ModMeta
+parseModMeta p = case lastMaybe f of
+	Just '+' -> AddMeta <$> mkf f' <*> v
+	Just '-' -> DelMeta <$> mkf f' <*> v
+	_ -> SetMeta <$> mkf f <*> v
+  where
+	(f, sv) = separate (== '=') p
+	f' = beginning f
+	v = pure (toMetaValue sv)
+	mkf fld = maybe (Left $ badfield fld) Right (toMetaField fld)
+	badfield fld = "Illegal metadata field name, \"" ++ fld ++ "\""
+
 {- Avoid putting too many fields in the map; extremely large maps make
  - the seriaization test slow due to the sheer amount of data.
  - It's unlikely that more than 100 fields of metadata will be used. -}
diff --git a/doc/git-annex.mdwn b/doc/git-annex.mdwn
index 17d78c555d..e0028d2d66 100644
--- a/doc/git-annex.mdwn
+++ b/doc/git-annex.mdwn
@@ -695,22 +695,22 @@ subdirectories).
 
 # UTILITY COMMANDS
 
-* `metadata file [field=value field+=value field-=value ...]`
+* `metadata [path ...] [-s field=value -s field+=value -s field-=value ...]`
 
   Each file can have any number of metadata fields attached to it,
   which each in turn have any number of values. This sets metadata
-  for a file, or if run without any values, shows its current metadata.
+  for the specified file or files, or if run without any values, shows
+  the current metadata.
 
-  To set a field's value, removing any old value(s), use field=value.
+  To set a field's value, removing any old value(s), use -s field=value.
 
-  To add an additional value, use field+=value.
+  To add an additional value, use -s field+=value.
 
-  To remove a value, use field-=value.
+  To remove a value, use -s field-=value.
 
   For example, to set some tags on a file:
 
-        	git annex metadata annexscreencast.ogv tag+=video tag+=screencast
-
+        	git annex metadata annexscreencast.ogv -s tag+=video -s tag+=screencast
 
 * `migrate [path ...]`