git-annex/Assistant/XMPP.hs
2015-01-21 12:50:09 -04:00

274 lines
8.2 KiB
Haskell

{- core xmpp support
-
- Copyright 2012-2013 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE OverloadedStrings #-}
module Assistant.XMPP where
import Assistant.Common
import Assistant.Types.NetMessager
import Assistant.Pairing
import Git.Sha (extractSha)
import Git
import Network.Protocol.XMPP hiding (Node)
import Data.Text (Text)
import qualified Data.Text as T
import qualified Data.Map as M
import Data.ByteString (ByteString)
import qualified Data.ByteString as B
import Data.XML.Types
import qualified "dataenc" Codec.Binary.Base64 as B64
{- Name of the git-annex tag, in our own XML namespace.
- (Not using a namespace URL to avoid unnecessary bloat.) -}
gitAnnexTagName :: Name
gitAnnexTagName = "{git-annex}git-annex"
{- Creates a git-annex tag containing a particular attribute and value. -}
gitAnnexTag :: Name -> Text -> Element
gitAnnexTag attr val = gitAnnexTagContent attr val []
{- Also with some content. -}
gitAnnexTagContent :: Name -> Text -> [Node] -> Element
gitAnnexTagContent attr val = Element gitAnnexTagName [(attr, [ContentText val])]
isGitAnnexTag :: Element -> Bool
isGitAnnexTag t = elementName t == gitAnnexTagName
{- Things that a git-annex tag can inserted into. -}
class GitAnnexTaggable a where
insertGitAnnexTag :: a -> Element -> a
extractGitAnnexTag :: a -> Maybe Element
hasGitAnnexTag :: a -> Bool
hasGitAnnexTag = isJust . extractGitAnnexTag
instance GitAnnexTaggable Message where
insertGitAnnexTag m elt = m { messagePayloads = elt : messagePayloads m }
extractGitAnnexTag = headMaybe . filter isGitAnnexTag . messagePayloads
instance GitAnnexTaggable Presence where
-- always mark extended away and set presence priority to negative
insertGitAnnexTag p elt = p
{ presencePayloads = extendedAway : negativePriority : elt : presencePayloads p }
extractGitAnnexTag = headMaybe . filter isGitAnnexTag . presencePayloads
data GitAnnexTagInfo = GitAnnexTagInfo
{ tagAttr :: Name
, tagValue :: Text
, tagElement :: Element
}
type Decoder = Message -> GitAnnexTagInfo -> Maybe NetMessage
gitAnnexTagInfo :: GitAnnexTaggable a => a -> Maybe GitAnnexTagInfo
gitAnnexTagInfo v = case extractGitAnnexTag v of
{- Each git-annex tag has a single attribute. -}
Just (tag@(Element _ [(attr, _)] _)) -> GitAnnexTagInfo
<$> pure attr
<*> attributeText attr tag
<*> pure tag
_ -> Nothing
{- A presence with a git-annex tag in it.
- Also includes a status tag, which may be visible in XMPP clients. -}
gitAnnexPresence :: Element -> Presence
gitAnnexPresence = insertGitAnnexTag $ addStatusTag $ emptyPresence PresenceAvailable
where
addStatusTag p = p
{ presencePayloads = status : presencePayloads p }
status = Element "status" [] [statusMessage]
statusMessage = NodeContent $ ContentText $ T.pack "git-annex"
{- A presence with an empty git-annex tag in it, used for letting other
- clients know we're around and are a git-annex client. -}
gitAnnexSignature :: Presence
gitAnnexSignature = gitAnnexPresence $ Element gitAnnexTagName [] []
{- XMPP client to server ping -}
xmppPing :: JID -> IQ
xmppPing selfjid = (emptyIQ IQGet)
{ iqID = Just "c2s1"
, iqFrom = Just selfjid
, iqTo = Just $ JID Nothing (jidDomain selfjid) Nothing
, iqPayload = Just $ Element xmppPingTagName [] []
}
xmppPingTagName :: Name
xmppPingTagName = "{urn:xmpp}ping"
{- A message with a git-annex tag in it. -}
gitAnnexMessage :: Element -> JID -> JID -> Message
gitAnnexMessage elt tojid fromjid = (insertGitAnnexTag silentMessage elt)
{ messageTo = Just tojid
, messageFrom = Just fromjid
}
{- A notification that we've pushed to some repositories, listing their
- UUIDs. -}
pushNotification :: [UUID] -> Presence
pushNotification = gitAnnexPresence . gitAnnexTag pushAttr . encodePushNotification
encodePushNotification :: [UUID] -> Text
encodePushNotification = T.intercalate uuidSep . map (T.pack . fromUUID)
decodePushNotification :: Text -> [UUID]
decodePushNotification = map (toUUID . T.unpack) . T.splitOn uuidSep
uuidSep :: Text
uuidSep = ","
{- A request for other git-annex clients to send presence. -}
presenceQuery :: Presence
presenceQuery = gitAnnexPresence $ gitAnnexTag queryAttr T.empty
{- A notification about a stage of pairing. -}
pairingNotification :: PairStage -> UUID -> JID -> JID -> Message
pairingNotification pairstage u = gitAnnexMessage $
gitAnnexTag pairAttr $ encodePairingNotification pairstage u
encodePairingNotification :: PairStage -> UUID -> Text
encodePairingNotification pairstage u = T.unwords $ map T.pack
[ show pairstage
, fromUUID u
]
decodePairingNotification :: Decoder
decodePairingNotification m = parse . words . T.unpack . tagValue
where
parse [stage, u] = PairingNotification
<$> readish stage
<*> (formatJID <$> messageFrom m)
<*> pure (toUUID u)
parse _ = Nothing
pushMessage :: PushStage -> JID -> JID -> Message
pushMessage = gitAnnexMessage . encode
where
encode (CanPush u shas) =
gitAnnexTag canPushAttr $ T.pack $ unwords $
fromUUID u : map fromRef shas
encode (PushRequest u) =
gitAnnexTag pushRequestAttr $ T.pack $ fromUUID u
encode (StartingPush u) =
gitAnnexTag startingPushAttr $ T.pack $ fromUUID u
encode (ReceivePackOutput n b) =
gitAnnexTagContent receivePackAttr (val n) $ encodeTagContent b
encode (SendPackOutput n b) =
gitAnnexTagContent sendPackAttr (val n) $ encodeTagContent b
encode (ReceivePackDone code) =
gitAnnexTag receivePackDoneAttr $ val $ encodeExitCode code
val = T.pack . show
decodeMessage :: Message -> Maybe NetMessage
decodeMessage m = decode =<< gitAnnexTagInfo m
where
decode i = M.lookup (tagAttr i) decoders >>= rundecoder i
rundecoder i d = d m i
decoders = M.fromList $ zip
[ pairAttr
, canPushAttr
, pushRequestAttr
, startingPushAttr
, receivePackAttr
, sendPackAttr
, receivePackDoneAttr
]
[ decodePairingNotification
, pushdecoder $ shasgen CanPush
, pushdecoder $ gen PushRequest
, pushdecoder $ gen StartingPush
, pushdecoder $ seqgen ReceivePackOutput
, pushdecoder $ seqgen SendPackOutput
, pushdecoder $
fmap (ReceivePackDone . decodeExitCode) . readish .
T.unpack . tagValue
]
pushdecoder a m' i = Pushing
<$> (formatJID <$> messageFrom m')
<*> a i
gen c i = c . toUUID <$> headMaybe (words (T.unpack (tagValue i)))
seqgen c i = do
packet <- decodeTagContent $ tagElement i
let seqnum = fromMaybe 0 $ readish $ T.unpack $ tagValue i
return $ c seqnum packet
shasgen c i = do
let (u:shas) = words $ T.unpack $ tagValue i
return $ c (toUUID u) (mapMaybe extractSha shas)
decodeExitCode :: Int -> ExitCode
decodeExitCode 0 = ExitSuccess
decodeExitCode n = ExitFailure n
encodeExitCode :: ExitCode -> Int
encodeExitCode ExitSuccess = 0
encodeExitCode (ExitFailure n) = n
{- Base 64 encoding a ByteString to use as the content of a tag. -}
encodeTagContent :: ByteString -> [Node]
encodeTagContent b = [NodeContent $ ContentText $ T.pack $ B64.encode $ B.unpack b]
decodeTagContent :: Element -> Maybe ByteString
decodeTagContent elt = B.pack <$> B64.decode s
where
s = T.unpack $ T.concat $ elementText elt
{- The JID without the client part. -}
baseJID :: JID -> JID
baseJID j = JID (jidNode j) (jidDomain j) Nothing
{- An XMPP chat message with an empty body. This should not be displayed
- by clients, but can be used for communications. -}
silentMessage :: Message
silentMessage = (emptyMessage MessageChat)
{ messagePayloads = [ emptybody ] }
where
emptybody = Element
{ elementName = "body"
, elementAttributes = []
, elementNodes = []
}
{- Add to a presence to mark its client as extended away. -}
extendedAway :: Element
extendedAway = Element "show" [] [NodeContent $ ContentText "xa"]
{- Add to a presence to give it a negative priority. -}
negativePriority :: Element
negativePriority = Element "priority" [] [NodeContent $ ContentText "-1"]
pushAttr :: Name
pushAttr = "push"
queryAttr :: Name
queryAttr = "query"
pairAttr :: Name
pairAttr = "pair"
canPushAttr :: Name
canPushAttr = "canpush"
pushRequestAttr :: Name
pushRequestAttr = "pushrequest"
startingPushAttr :: Name
startingPushAttr = "startingpush"
receivePackAttr :: Name
receivePackAttr = "rp"
sendPackAttr :: Name
sendPackAttr = "sp"
receivePackDoneAttr :: Name
receivePackDoneAttr = "rpdone"
shasAttr :: Name
shasAttr = "shas"