draft out user notification

TODO.md

@@ -5,8 +5,8 @@
 ### Required
 
 - [ ] E-Mail notification
-- [ ] Security mechanism has to be triggered, if present
+- [x] Security mechanism has to be triggered, if present
-- [ ] Buy products in stock
+- [x] Buy products in stock
 
 ### Optional
 

src/Control/Buy.hs

@@ -43,12 +43,14 @@ buy auth pds = do
       void $ addToUserBalance auid (-price) conn
       newBalance <- userBalanceSelect conn auid
       userUpdateTimestamp auth
-      return $ PurchaseResult
+      let result = PurchaseResult
         ( if newBalance < 0
           then PurchaseDebtful
           else PurchaseOK
         )
         missing
+      userNotify auth result
+      return result
     Nothing -> do
       void $ insertNewJournalEntry
         (JournalSubmit

src/Control/User.hs

@@ -142,3 +142,11 @@ userTransfer Nothing _ =
   throwError $ err401
     { errBody = "No Authentication present."
     }
+
+userNotify
+  :: Maybe (Int, AuthMethod)
+  -> [PurchaseDetail]
+  -> PurchaseResult
+  -> MateHandler ()
+userNotify (Just (auid, method)) boughtItems (PruchaseResult flag missing) = do
+