Add encoding and decoding of login datas a function.

src/Scylla/Login.elm

@@ -1,11 +1,30 @@
 module Scylla.Login exposing (..)
-import Scylla.Api exposing (ApiToken)
+import Scylla.Api exposing (ApiUrl, ApiToken)
 import Json.Decode as Decode exposing (Decoder, int, string, float, list, value, dict, bool)
 import Json.Decode.Pipeline exposing (required, optional)
+import Json.Encode as Encode
 
 type alias Username = String
 type alias Password = String
 
+type alias LoginInfo = (ApiToken, ApiUrl, Username)
+
+encodeLoginInfo : LoginInfo -> Decode.Value
+encodeLoginInfo (t,a,u) = Encode.string (t ++ "," ++ a ++ "," ++ u)
+
+parseLoginInfoString : String -> Decoder LoginInfo
+parseLoginInfoString s = case String.indexes "," s of
+    [ fst, snd ] -> Decode.succeed
+        ( (String.slice 0 fst s)
+        , (String.slice (fst + 1) snd s)
+        , (String.dropLeft snd s)
+        )
+    _ -> Decode.fail "Incorrectly formatted Login Info string"
+
+loginInfoDecoder : Decoder LoginInfo
+loginInfoDecoder = string
+    |> Decode.andThen parseLoginInfoString
+
 type alias LoginResponse =
     { userId : String
     , accessToken : ApiToken