Revert "p2p --link now defaults to setting up a bi-directional link"

This reverts commit 3037feb1bf.

On second thought, this was an overcomplication of what should be the
lowest-level primitive. Let's build bi-directional links at the pairing
level with eg magic wormhole.

Command/P2P.hs

@@ -10,10 +10,15 @@ module Command.P2P where
 import Command
 import P2P.Address
 import P2P.Auth
-import P2P.Annex
+import P2P.IO
+import qualified P2P.Protocol as P2P
 import Utility.AuthToken
 import Git.Types
 import qualified Git.Remote
+import qualified Git.Command
+import qualified Annex
+import Annex.UUID
+import Config
 
 cmd :: Command
 cmd = command "p2p" SectionSetup
@@ -24,13 +29,10 @@ data P2POpts
 	= GenAddresses
 	| LinkRemote
 
-data LinkDirection = BiDirectional | OneWay
-
-optParser :: CmdParamsDesc -> Parser (P2POpts, Maybe RemoteName, LinkDirection)
-optParser _ = (,,)
+optParser :: CmdParamsDesc -> Parser (P2POpts, Maybe RemoteName)
+optParser _ = (,)
 	<$> (genaddresses <|> linkremote)
 	<*> optional name
-	<*> direction
   where
 	genaddresses = flag' GenAddresses
 		( long "gen-addresses"
@@ -45,17 +47,23 @@ optParser _ = (,,)
 		<> metavar paramName
 		<> help "name of remote"
 		)
-	direction = flag BiDirectional OneWay
-		( long "one-way"
-		<> help "make one-way link, rather than default bi-directional link"
-		)
 
-seek :: (P2POpts, Maybe RemoteName, LinkDirection) -> CommandSeek
-seek (GenAddresses, _, _) = genAddresses =<< loadP2PAddresses
-seek (LinkRemote, Just name, direction) = commandAction $
-	linkRemote direction (Git.Remote.makeLegalName name)
-seek (LinkRemote, Nothing, direction) = commandAction $
-	linkRemote direction =<< unusedPeerRemoteName
+seek :: (P2POpts, Maybe RemoteName) -> CommandSeek
+seek (GenAddresses, _) = genAddresses =<< loadP2PAddresses
+seek (LinkRemote, Just name) = commandAction $
+	linkRemote (Git.Remote.makeLegalName name)
+seek (LinkRemote, Nothing) = commandAction $
+	linkRemote =<< unusedPeerRemoteName
+
+unusedPeerRemoteName :: Annex RemoteName
+unusedPeerRemoteName = go (1 :: Integer) =<< usednames
+  where
+	usednames = mapMaybe remoteName . remotes <$> Annex.gitRepo
+	go n names = do
+		let name = "peer" ++ show n
+		if name `elem` names
+			then go (n+1) names
+			else return name
 
 -- Only addresses are output to stdout, to allow scripting.
 genAddresses :: [P2PAddress] -> Annex ()
@@ -69,8 +77,8 @@ genAddresses addrs = do
 			map (`P2PAddressAuth` authtoken) addrs
 
 -- Address is read from stdin, to avoid leaking it in shell history.
-linkRemote :: LinkDirection -> RemoteName -> CommandStart
-linkRemote direction remotename = do
+linkRemote :: RemoteName -> CommandStart
+linkRemote remotename = do
 	showStart "p2p link" remotename
 	next $ next prompt
   where
@@ -87,13 +95,24 @@ linkRemote direction remotename = do
 				Nothing -> do
 					liftIO $ hPutStrLn stderr "Unable to parse that address, please check its format and try again."
 					prompt
-				Just addr -> do
-					linkbackto <- case direction of
-						OneWay -> return []
-						BiDirectional -> do
-							myaddrs <- loadP2PAddresses
-							authtoken <- liftIO $ genAuthToken 128
-							storeP2PAuthToken authtoken
-							return $ map (`P2PAddressAuth` authtoken) myaddrs
-					linkAddress addr linkbackto remotename
-						>>= either giveup return
+				Just addr -> setup addr
+	setup (P2PAddressAuth addr authtoken) = do
+		g <- Annex.gitRepo
+		conn <- liftIO $ connectPeer g addr
+			`catchNonAsync` connerror
+		u <- getUUID
+		v <- liftIO $ runNetProto conn $ P2P.auth u authtoken
+		case v of
+			Right (Just theiruuid) -> do
+				ok <- inRepo $ Git.Command.runBool
+					[ Param "remote", Param "add"
+					, Param remotename
+					, Param (formatP2PAddress addr)
+					]
+				when ok $ do
+					storeUUIDIn (remoteConfig remotename "uuid") theiruuid
+					storeP2PRemoteAuthToken addr authtoken
+				return ok
+			Right Nothing -> giveup "Unable to authenticate with peer. Please check the address and try again."
+			Left e -> giveup $ "Unable to authenticate with peer: " ++ e
+	connerror e = giveup $ "Unable to connect with peer. Please check that the peer is connected to the network, and try again. ("  ++ show e ++ ")"