1 module NmcTransform ( seedNmcDom
5 import Prelude hiding (lookup)
6 import Data.ByteString.Lazy (ByteString)
7 import Data.Map (lookup, delete, size)
8 import Control.Monad (foldM)
9 import Data.Aeson (decode)
13 -- | Perform query and return error string or parsed domain object
15 (String -> IO (Either String ByteString)) -- ^ query operation action
17 -> IO (Either String NmcDom) -- ^ error string or domain
18 queryNmcDom queryOp key = do
21 Left estr -> return $ Left estr
22 Right str -> case decode str :: Maybe NmcDom of
23 Nothing -> return $ Left $ "Unparseable value: " ++ (show str)
24 Just dom -> return $ Right dom
26 -- | Try to fetch "import" object and merge it into the base domain
27 -- Original "import" element is removed, but new imports from the
28 -- imported objects are processed recursively until there are none.
30 (String -> IO (Either String ByteString)) -- ^ query operation action
31 -> Int -- ^ recursion counter
32 -> NmcDom -- ^ base domain
33 -> IO (Either String NmcDom) -- ^ result with merged import
34 mergeImport queryOp depth base = do
36 mbase = mergeSelf base
37 base' = mbase {domImport = Nothing}
39 if depth <= 0 then return $ Left "Nesting of imports is too deep"
40 else case domImport mbase of
41 Nothing -> return $ Right base'
42 Just keys -> foldM mergeImport1 (Right base') keys
44 mergeImport1 (Left err) _ = return $ Left err
45 mergeImport1 (Right acc) key = do
46 sub <- queryNmcDom queryOp key
48 Left err -> return $ Left err
49 Right sub' -> mergeImport queryOp (depth - 1) $
50 sub' `mergeNmcDom` acc
52 -- | If there is an element in the map with key "", merge the contents
53 -- and remove this element. Do this recursively.
54 mergeSelf :: NmcDom -> NmcDom
58 base' = base {domMap = removeSelf map}
59 removeSelf Nothing = Nothing
60 removeSelf (Just map) = if size map' == 0 then Nothing else Just map'
61 where map' = delete "" map
66 case lookup "" map' of
68 Just sub -> (mergeSelf sub) `mergeNmcDom` base'
69 -- recursion depth limited by the size of the record
71 -- | SRV case - remove everyting and filter SRV records
72 normalizeSrv :: String -> String -> NmcDom -> NmcDom
73 normalizeSrv serv proto dom =
74 emptyNmcDom {domService = fmap (filter needed) (domService dom)}
76 needed r = srvName r == serv && srvProto r == proto
78 -- | Presence of some elements require removal of some others
79 normalizeDom :: NmcDom -> NmcDom
80 normalizeDom dom = foldr id dom [ srvNormalizer
85 nsNormalizer dom = case domNs dom of
87 Just ns -> emptyNmcDom { domNs = domNs dom, domEmail = domEmail dom }
88 translateNormalizer dom = case domTranslate dom of
90 Just tr -> dom { domMap = Nothing }
91 srvNormalizer dom = dom { domService = Nothing, domMx = makemx }
93 makemx = case domService dom of
95 Just svl -> Just $ map makerec (filter needed svl)
97 needed sr = srvName sr == "smtp"
98 && srvProto sr == "tcp"
100 makerec sr = (show (srvPrio sr)) ++ " " ++ (srvHost sr)
102 -- | Merge imports and Selfs and follow the maps tree to get dom
104 (String -> IO (Either String ByteString)) -- ^ query operation action
105 -> [String] -- ^ subdomain chain
106 -> NmcDom -- ^ base domain
107 -> IO (Either String NmcDom) -- ^ fully processed result
108 descendNmcDom queryOp subdom base = do
109 base' <- mergeImport queryOp 10 base
111 [] -> return $ fmap normalizeDom base'
112 -- A hack to handle SRV records: don't descend if ["_prot","_serv"]
113 [('_':p),('_':s)] -> return $ fmap (normalizeSrv s p) base'
116 Left err -> return base'
118 case domMap base'' of
119 Nothing -> return $ Right emptyNmcDom
122 Nothing -> return $ Right emptyNmcDom
123 Just sub -> descendNmcDom queryOp ds sub
125 -- | Initial NmcDom populated with "import" only, suitable for "descend"
127 String -- ^ domain key (without namespace prefix)
128 -> NmcDom -- ^ resulting seed domain
129 seedNmcDom dn = emptyNmcDom { domImport = Just (["d/" ++ dn])}