add annex: url parser

Changed the format of the url to use annex: rather than annex::

The reason is that in the future, might want to support an url that
includes an uriAuthority part, eg:

annex://foo@example.com:42/358ff77e-0bc3-11ef-bc49-872e6695c0e3?type=directory&encryption=none&directory=/mnt/foo/"

To parse that foo@example.com:42 as an uriAuthority it needs to start with
annex: rather than annex::

That would also need something to be done with uriAuthority, and also
the uriPath (the UUID) is prefixed with "/" in that example. So the
current parser won't handle that example currently. But this leaves the
possibility for expansion.

Sponsored-by: Joshua Antonishen on Patreon

CmdLine/GitRemoteAnnex.hs

@@ -11,11 +11,14 @@ import Annex.Common
 import qualified Annex
 import qualified Git.CurrentRepo
 import Annex.UUID
+import Network.URI
 
 run :: [String] -> IO ()
-run (_remotename:url:[]) = do
+run (_remotename:url:[]) = case parseSpecialRemoteUrl url of
-	state <- Annex.new =<< Git.CurrentRepo.get
+	Left e -> giveup e
-	Annex.eval state (run' url)
+	Right src -> do
+		state <- Annex.new =<< Git.CurrentRepo.get
+		Annex.eval state (run' url)
 run (_remotename:[]) = giveup "remote url not configured"
 run _ = giveup "expected remote name and url parameters"
 
@@ -109,3 +112,30 @@ splitLine l =
 	let (c, sv) = break (== ' ') l
 	    v = if null sv then sv else drop 1 sv
 	in (c, v)
+
+data SpecialRemoteConfig = SpecialRemoteConfig
+	{ specialRemoteUUID :: UUID
+	, specialRemoteParams :: [(String, String)]
+	}
+	deriving (Show)
+
+-- The url for a special remote looks like
+-- annex:uuid?param=value&param=value...
+parseSpecialRemoteUrl :: String -> Either String SpecialRemoteConfig
+parseSpecialRemoteUrl s = case parseURI s of
+	Nothing -> Left "URL parse failed"
+	Just u -> case uriScheme u of
+		"annex:" -> case uriPath u of
+			"" -> Left "annex: URL did not include a UUID"
+			(':':_) -> Left "annex: URL malformed"
+			p -> Right $ SpecialRemoteConfig
+				{ specialRemoteUUID = toUUID p
+				, specialRemoteParams = parsequery u
+				}
+		_ -> Left "Not an annex: URL"
+  where
+	parsequery u = map parsekv $ splitc '&' (drop 1 (uriQuery u))
+	parsekv s =
+		let (k, sv) = break (== '=') s
+		    v = if null sv then sv else drop 1 sv
+		in (unEscapeString k, unEscapeString v)

doc/git-remote-annex.mdwn

@@ -4,7 +4,7 @@ git-remote-annex - remote helper program to store a git repository in a git-anne
 
 # SYNOPSIS
 
-git fetch annex::uuid?param=value&param=value...
+git fetch annex:uuid?param=value&param=value...
 
 # DESCRIPTION
 
@@ -17,13 +17,13 @@ encryption=shared or encryption=hybrid. (Since those types of encryption
 rely on a cipher that is checked into the git repository, cloning from
 such a special remote would present a chicken and egg problem.)
 
-The format of the remote URL is "annex::" followed by the UUID of the
+The format of the remote URL is "annex:" followed by the UUID of the
 special remote, and then followed by all of the configuration parameters of
 the special remote.
 
 For example, to clone from a directory special remote:
 
-    git clone annex::358ff77e-0bc3-11ef-bc49-872e6695c0e3?type=directory&encryption=none&directory=/mnt/foo/
+    git clone annex:358ff77e-0bc3-11ef-bc49-872e6695c0e3?type=directory&encryption=none&directory=/mnt/foo/
 
 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
@@ -34,12 +34,12 @@ set when pulling or pushing.
 As a useful shorthand, when the special remote has already been enabled,
 the configuration parameters can be omitted. For example:
 
-	git push annex::358ff77e-0bc3-11ef-bc49-872e6695c0e3 master
+	git push annex:358ff77e-0bc3-11ef-bc49-872e6695c0e3 master
 
 This also makes it easy to configure the url for an existing special remote,
 making it usable by git:
 
-	git config remote.foo.url annex::358ff77e-0bc3-11ef-bc49-872e6695c0e3
+	git config remote.foo.url annex:358ff77e-0bc3-11ef-bc49-872e6695c0e3
 	git fetch foo master
 
 Configuring the url like that is automatically done when cloning from a