2 files changed, 57 insertions, 0 deletions
diff --git a/server/src/Validation/Atomic.hs b/server/src/Validation/Atomic.hs
new file mode 100644
index 0000000..d15ad49
--- /dev/null
+++ b/server/src/Validation/Atomic.hs
@@ -0,0 +1,32 @@
+module Validation.Atomic
+  ( nonEmpty
+  , nonNullNumber
+  -- , number
+  ) where
+
+import           Data.Text  (Text)
+import qualified Data.Text  as T
+
+import qualified Common.Msg as Msg
+
+nonEmpty :: Text -> Maybe Text
+nonEmpty str =
+  if T.null str
+    then Just $ Msg.get Msg.Form_NonEmpty
+    else Nothing
+
+nonNullNumber :: Int -> Maybe Text
+nonNullNumber n =
+  if n == 0
+     then Just $ Msg.get Msg.Form_NonNullNumber
+    else Nothing
+
+-- number :: (Int -> Bool) -> Text -> Maybe Int
+-- number numberForm str =
+--   case reads (T.unpack str) :: [(Int, String)] of
+--     (num, _) : _ ->
+--       if numberForm num
+--         then Just num
+--         else Nothing
+--     _ ->
+--       Nothing
diff --git a/server/src/Validation/CreatePayment.hs b/server/src/Validation/CreatePayment.hs
new file mode 100644
index 0000000..fbcdb7c
--- /dev/null
+++ b/server/src/Validation/CreatePayment.hs
@@ -0,0 +1,25 @@
+module Validation.CreatePayment
+  ( validate
+  ) where
+
+import           Data.Maybe                 (catMaybes)
+
+import           Common.Model.CreatePayment (CreatePayment (..),
+                                             CreatePaymentError (..))
+import qualified Validation.Atomic          as Atomic
+
+validate :: CreatePayment -> Maybe CreatePaymentError
+validate p =
+  if not . null . catMaybes $ [ nameError, costError ]
+    then Just createPaymentError
+    else Nothing
+  where
+    nameError = Atomic.nonEmpty . _createPayment_name $ p
+    costError = Atomic.nonNullNumber . _createPayment_cost $ p
+    createPaymentError = CreatePaymentError
+      { _createPaymentError_name      = nameError
+      , _createPaymentError_cost      = costError
+      , _createPaymentError_date      = Nothing
+      , _createPaymentError_category  = Nothing
+      , _createPaymentError_frequency = Nothing
+      }