wip JsonRpc response parsing

[pdns-pipe-nmc.git] / Data / JsonRpc.hs

diff --git a/Data/JsonRpc.hs b/Data/JsonRpc.hs
index b1879bccef89f57638ad44a122ad2d93f1c892c1..15b1d88e99d9e447ccb650b061707458350bfc0b 100644 (file)
--- a/Data/JsonRpc.hs
+++ b/Data/JsonRpc.hs
@@ -1,29 +1,82 @@
-module JsonRpc  ( JsonRpcRequest(..)
-                , JsonRpcNotification(..)
-                , JsonRpcResponse(..)
+{-# LANGUAGE OverloadedStrings #-}
+
+module JsonRpc  ( JsonRpcVersion(JsonRpcV1, JsonRpcV2)
+                , JsonRpcRequest
+                , JsonRpcNotification
+                , JsonRpcError(..)
+                , parseJsonRpc
                 ) where
 
-import Data.ByteString (ByteString)
+import Data.ByteString.Lazy (ByteString)
 import Control.Applicative ((<$>), (<*>), empty)
+import Data.Either
 import Data.Aeson
 
-data JsonRpcRequest = JsonRpcRequest { jrpcReqMethod :: ByteString
-                                     , jrpcReqParams :: [ByteString]
-                                     , jrpcReqId     :: ByteString
+data JsonRpcVersion = JsonRpcV1 | JsonRpcV2
+        deriving (Show)
+
+data JsonRpcRequest = JsonRpcRequest { jrpcVersion    :: JsonRpcVersion
+                                     , jrpcReqMethod  :: ByteString
+                                     , jrpcReqParams  :: [ByteString]
+                                     , jrpcReqId      :: ByteString
                                      } deriving (Show)
+instance ToJSON JsonRpcRequest where
+  toJSON (JsonRpcRequest version method params id) =
+    let l = [ "method" .= method, "params" .= params, "id" .= id ]
+    in case version of
+      JsonRpcV1 -> object l
+      JsonRpcV2 -> object $ ("jsonrpc" .= toJSON ("2.0" :: ByteString)):l
 
-data JsonRpcNotification = JsonRpcNotification { jrpcNtfMethod :: ByteString
-                                               , jrpcNtfParams :: [ByteString]
-                                               } deriving (Show)
+data JsonRpcNotification = JsonRpcNotification
+                                     { jrpcNtfVersion :: JsonRpcVersion
+                                     , jrpcNtfMethod  :: ByteString
+                                     , jrpcNtfParams  :: [ByteString]
+                                     } deriving (Show)
+instance ToJSON JsonRpcNotification where
+  toJSON (JsonRpcNotification version method params) =
+    let l = [ "method" .= method, "params" .= params ]
+    in case version of
+      JsonRpcV1 -> object l
+      JsonRpcV2 -> object $ ("jsonrpc" .= toJSON ("2.0" :: ByteString)):l
 
 data JsonRpcError = JsonRpcError { jrpcErrCode    :: Int
                                  , jrpcErrMessage :: ByteString
                                  , jrpcErrData    :: Maybe Value
                                  } deriving (Show)
+instance FromJSON JsonRpcError where
+  parseJSON (Object o) = JsonRpcError
+                                <$> o .: "code"
+                                <*> o .: "error"
+                                <*> o .: "data"
+  parseJSON x = return $ JsonRpcError
+                                (-32600)
+                                "Unparseable error object"
+                                Nothing
 
 data JsonRpcResponse = JsonRpcResponse { jrpcRspResult :: Maybe Value
                                        , jrpcRspError  :: JsonRpcError
                                        , jrpcRspId     :: ByteString
                                        } deriving (Show)
+instance FromJSON JsonRpcResponse where
+  parseJSON (Object o) = JsonRpcResponse
+                                <$> o .: "result"
+                                <*> o .: "error"
+                                <*> o .: "id"
+  parseJSON x = return $ JsonRpcResponse
+                                Nothing
+                                (JsonRpcError
+                                        (-32700)
+                                        "Unparseable response object"
+                                        Nothing
+                                )
+                                ""
 
-
+parseJsonRpc :: (FromJSON a) => ByteString -> Either JsonRpcError a
+parseJsonRpc s = case (decode s :: Maybe JsonRpcResponse) of
+  Just (JsonRpcResponse result error id) ->
+    case result of
+      Just v -> case (fromJSON v) of
+        Success a -> Right a
+        Error s   -> Left $ JsonRpcError (-32900) "Unparseable result" Nothing
+      Nothing -> Left error
+  Nothing -> Left $ JsonRpcError (-32800) "Unparseable response" Nothing