Consolidate auth functions

src/Auth.hs

@@ -0,0 +1,37 @@
+import qualified Data.Aeson as JSON
+import qualified Data.ByteString.Char8 as BS
+import Crypto.BCrypt
+import Control.Monad (mzero)
+import Control.Applicative ( (<$>), (<*>) )
+import Database.PostgreSQL.Simple
+
+data AuthUser = AuthUser {
+    userId :: String
+  , userPass :: String
+  , userRole :: String
+  }
+
+instance JSON.FromJSON AuthUser where
+  parseJSON (JSON.Object v) = AuthUser <$>
+                         v JSON..: "id" <*>
+                         v JSON..: "pass" <*>
+                         v JSON..: "role"
+  parseJSON _          = mzero
+
+type DbRole = BS.ByteString
+
+data LoginAttempt =
+    NoCredentials
+  | MalformedAuth
+  | LoginFailed
+  | LoginSuccess DbRole
+  deriving (Eq, Show)
+
+checkPass :: BS.ByteString -> BS.ByteString -> Bool
+checkPass = validatePassword
+
+setRole :: Connection -> DbRole -> IO ()
+setRole conn role = execute conn "set role ?" (Only role)
+
+resetRole :: Connection -> IO ()
+resetRole = flip execute_ "reset role"