git-remote-annex: Display full url when using remote with the shorthand url

Annex/SpecialRemote/Config.hs

@@ -107,17 +107,23 @@ commonFieldParsers =
 		(FieldDesc "name for the special remote")
 	, optionalStringParser sameasNameField HiddenField
 	, optionalStringParser sameasUUIDField HiddenField
-	, optionalStringParser typeField
-		(FieldDesc "type of special remote")
 	, autoEnableFieldParser
 	, costParser costField
 		(FieldDesc "default cost of this special remote")
+	, optionalStringParser preferreddirField
+		(FieldDesc "directory whose content is preferred")
+	] ++ essentialFieldParsers
+
+{- Parsers for fields that are common to all special remotes, and are
+ - also essential to include in eg, annex:: urls. -}
+essentialFieldParsers :: [RemoteConfigFieldParser]
+essentialFieldParsers =
+	[ optionalStringParser typeField
+		(FieldDesc "type of special remote")
 	, yesNoParser exportTreeField (Just False)
 		(FieldDesc "export trees of files to this remote")
 	, yesNoParser importTreeField (Just False)
 		(FieldDesc "import trees of files from this remote")
-	, optionalStringParser preferreddirField
-		(FieldDesc "directory whose content is preferred")
 	]
 
 autoEnableFieldParser :: RemoteConfigFieldParser

CmdLine/GitRemoteAnnex.hs

@@ -22,10 +22,12 @@ import qualified Git.Remote
 import qualified Git.Remote.Remove
 import qualified Git.Version
 import qualified Annex.SpecialRemote as SpecialRemote
+import qualified Annex.SpecialRemote.Config as SpecialRemote
 import qualified Annex.Branch
 import qualified Annex.BranchState
 import qualified Types.Remote as Remote
 import qualified Logs.Remote
+import qualified Remote.External
 import Remote.Helper.Encryptable (parseEncryptionMethod)
 import Annex.Transfer
 import Backend.GitRemoteAnnex
@@ -72,17 +74,18 @@ run (remotename:url:[]) =
 		Right src -> do
 			repo <- getRepo
 			state <- Annex.new repo
-			Annex.eval state (run' src)
+			Annex.eval state (run' src url')
 run (_remotename:[]) = giveup "remote url not configured"
 run _ = giveup "expected remote name and url parameters"
 
-run' :: SpecialRemoteConfig -> Annex ()
+run' :: SpecialRemoteConfig -> String -> Annex ()
-run' src = do
+run' src url = do
 	sab <- startAnnexBranch
 	-- Prevent any usual git-annex output to stdout, because
 	-- the output of this command is being parsed by git.
 	doQuietAction $
 		withSpecialRemote src sab $ \rmt -> do
+			reportFullUrl url rmt
 			ls <- lines <$> liftIO getContents
 			go rmt ls emptyState
   where
@@ -464,6 +467,50 @@ parseSpecialRemoteUrl url remotename = case parseURI url of
 		    v = if null sv then sv else drop 1 sv
 		in (Proposed (unEscapeString k), Proposed (unEscapeString v))
 			
+getSpecialRemoteUrl :: Remote -> Annex (Maybe String)
+getSpecialRemoteUrl rmt = do
+	rcp <- Remote.configParser (Remote.remotetype rmt)
+		(unparsedRemoteConfig (Remote.config rmt))
+	return $ genSpecialRemoteUrl rmt rcp
+
+genSpecialRemoteUrl :: Remote -> RemoteConfigParser -> Maybe String
+genSpecialRemoteUrl rmt rcp
+	-- Fields that are accepted by remoteConfigRestPassthrough
+	-- are not necessary to include in the url, except perhaps for
+	-- external special remotes. If an external special remote sets
+	-- some such fields, cannot generate an url.
+	| Remote.typename (Remote.remotetype rmt) == Remote.typename Remote.External.remote
+		&& any (`notElem` knownfields) (M.keys c) = Nothing
+	| otherwise = Just $ 
+		"annex::" ++ fromUUID (Remote.uuid rmt) ++ "?" ++
+			intercalate "&" (map configpair cs)
+  where
+	configpair (k, v) = conv k ++ "=" ++ conv v
+	conv = escapeURIString isUnescapedInURIComponent
+		. fromProposedAccepted
+	
+	cs = M.toList $ M.filterWithKey (\k _ -> k `elem` safefields) c
+	c = unparsedRemoteConfig $ Remote.config rmt
+	
+	-- Hidden fields are used for internal stuff like ciphers
+	-- that should not be included in the url.
+	safefields = map parserForField $
+		filter (\p -> fieldDesc p /= HiddenField) ps
+
+	knownfields = map parserForField ps
+
+	ps = SpecialRemote.essentialFieldParsers
+		++ remoteConfigFieldParsers rcp
+
+reportFullUrl :: String -> Remote -> Annex ()
+reportFullUrl url rmt = 
+	when (url == "annex::") $
+		getSpecialRemoteUrl rmt >>= \case
+			Nothing -> noop
+			Just fullurl -> 
+				liftIO $ hPutStrLn stderr $ 
+					"Full remote url: " ++ fullurl
+
 -- Runs an action with a Remote as specified by the SpecialRemoteConfig.
 withSpecialRemote :: SpecialRemoteConfig -> StartAnnexBranch -> (Remote -> Annex a) -> Annex a
 withSpecialRemote (ExistingSpecialRemote remotename) _ a =

Command/InitRemote.hs

@@ -157,6 +157,7 @@ describeOtherParamsFor c t = do
 		( maybeAddJSONField "whatelse" $ M.fromList $ mkjson l
 		, liftIO $ forM_ l $ \(p, fd, vd) -> case fd of
 			HiddenField -> return ()
+			DeprecatedField -> return ()
 			FieldDesc d -> do
 				putStrLn p
 				putStrLn ("\t" ++ d)
@@ -171,6 +172,7 @@ describeOtherParamsFor c t = do
 	mkjson = mapMaybe $ \(p, fd, vd) ->
 		case fd of
 			HiddenField -> Nothing
+			DeprecatedField -> Nothing
 			FieldDesc d -> Just 
 				( T.pack p
 				, M.fromList

Remote/Helper/Chunked.hs

@@ -58,7 +58,7 @@ noChunks _ = False
 
 chunkConfigParsers :: [RemoteConfigFieldParser]
 chunkConfigParsers =
-	[ optionalStringParser chunksizeField HiddenField -- deprecated
+	[ optionalStringParser chunksizeField DeprecatedField
 	, optionalStringParser chunkField
 		(FieldDesc "size of chunks (eg, 1MiB)")
 	]

Types/RemoteConfig.hs

@@ -51,6 +51,8 @@ data RemoteConfigFieldParser = RemoteConfigFieldParser
 data FieldDesc
 	= FieldDesc String
 	| HiddenField
+	| DeprecatedField
+	deriving (Eq)
 
 newtype ValueDesc = ValueDesc String
 

doc/git-remote-annex.mdwn

@@ -20,8 +20,8 @@ For example, to clone from a directory special remote:
 
     git clone annex::358ff77e-0bc3-11ef-bc49-872e6695c0e3?type=directory&encryption=none&directory=/mnt/foo/
 
-When configuring the url of an existing special remote, a
+But you don't need to generate such an url yourself. Instead, you can use
-shorter url of "annex::" is sufficient. For example:
+the shorthand url of "annex::" with an existing special remote.
 
     git-annex initremote foo type=directory encryption=none directory=/mnt/foo
     git config remote.foo.url annex::
@@ -32,6 +32,10 @@ special remote. To make [[git-annex-initremote]](1) and
 [[git-annex-enableremote]](1) configure the url, pass them the `--with-url`
 option.
 
+When using the shorthand "annex::" url, the full url will be displayed
+each time you git pull or push, when it's possible for git-annex to
+determine it.
+
 When a special remote needs some additional credentials to be provided,
 they are not included in the URL, and need to be provided when cloning from
 the special remote. That is typically done by setting environment

doc/todo/git-remote-annex.mdwn

@@ -10,20 +10,15 @@ will be available to users who don't use datalad.
 
 This is implememented and working. Remaining todo list for it:
 
+* When git clone is used with an annex:: url that is for a directory
+  special remote and is missing directory=, for example, it does
+  not display any useful error message. git fetch does, but it seems
+  git clone eats git-remote-annex stderr.
+
 * Cloning from an annex:: url with importtree=yes doesn't work
   (with or without exporttree=yes). This is because the ContentIdentifier
   db is not populated. It should be possible to work around this.
 
-* It would be nice if git-annex could generate an annex:: url
-  for a special remote and show it to the user, eg when 
-  they have set the shorthand "annex::" url, so they know the full url.
-  `git-annex info $remote` could also display it.
-  Currently, the user has to remember how the special remote was
-  configured and replicate it all in the url.
-
-  There are some difficulties to doing this, including that
-  RemoteConfig can have hidden fields that should be omitted.
-
 * datalad-annex supports cloning from the web special remote,
   using an url that contains the result of pushing to eg, a directory
   special remote.