Correct order upserting

src/Order.hs

@@ -14,8 +14,7 @@ import GHC.Generics
 import Test.QuickCheck
 
 -- | Type to represent a ZGo order
-data ZGoOrder =
-  ZGoOrder
+data ZGoOrder = ZGoOrder
   { q_id :: Maybe ObjectId
   , qaddress :: T.Text
   , qsession :: T.Text
@@ -30,8 +29,7 @@ data ZGoOrder =
   , qexternalInvoice :: T.Text
   , qshortCode :: T.Text
   , qtoken :: T.Text
-    }
-  deriving (Eq, Show, Generic)
+  } deriving (Eq, Show, Generic)
 
 instance ToJSON ZGoOrder where
   toJSON (ZGoOrder i a s ts c cur p t tZ l paid eI sC tk) =
@@ -74,7 +72,7 @@ instance ToJSON ZGoOrder where
 instance FromJSON ZGoOrder where
   parseJSON =
     withObject "Order" $ \obj -> do
-      i <- obj .: "_id"
+      i <- obj .:? "_id"
       a <- obj .: "address"
       s <- obj .: "session"
       ts <- obj .: "timestamp"
@@ -88,24 +86,7 @@ instance FromJSON ZGoOrder where
       eI <- obj .: "externalInvoice"
       sC <- obj .: "shortCode"
       tk <- obj .: "token"
-      pure $
-        ZGoOrder
-          (if not (null i)
-             then Just (read i)
-             else Nothing)
-          a
-          s
-          ts
-          c
-          cur
-          p
-          t
-          tZ
-          l
-          pd
-          eI
-          sC
-          tk
+      pure $ ZGoOrder (read =<< i) a s ts c cur p t tZ l pd eI sC tk
 
 instance Val ZGoOrder where
   val (ZGoOrder i a s ts c cur p t tZ l pd eI sC tk) =
@@ -160,13 +141,11 @@ instance Val ZGoOrder where
   cast' _ = Nothing
 
 -- Type to represent an order line item
-data LineItem =
-  LineItem
+data LineItem = LineItem
   { lqty :: Double
   , lname :: T.Text
   , lcost :: Double
-    }
-  deriving (Eq, Show)
+  } deriving (Eq, Show)
 
 instance ToJSON LineItem where
   toJSON (LineItem q n c) = object ["qty" .= q, "name" .= n, "cost" .= c]
@@ -210,7 +189,14 @@ upsertXeroOrder :: ZGoOrder -> Action IO ()
 upsertXeroOrder o = do
   let order = val $ updateOrderTotals o
   case order of
-    Doc d -> upsert (select ["externalInvoice" =: qexternalInvoice o, "shortCode" =: qshortCode o] "orders") d
+    Doc d ->
+      upsert
+        (select
+           [ "externalInvoice" =: qexternalInvoice o
+           , "shortCode" =: qshortCode o
+           ]
+           "orders")
+        d
     _ -> return ()
 
 -- | Function to update order totals from items
@@ -247,13 +233,20 @@ findOrder :: T.Text -> Action IO (Maybe Document)
 findOrder s = findOne (select ["session" =: s, "closed" =: False] "orders")
 
 findXeroOrder :: T.Text -> T.Text -> T.Text -> Action IO (Maybe Document)
-findXeroOrder a i s = findOne (select ["address" =: a, "externalInvoice" =: i, "shortCode" =: s] "orders")
+findXeroOrder a i s =
+  findOne
+    (select ["address" =: a, "externalInvoice" =: i, "shortCode" =: s] "orders")
 
 findOrderById :: String -> Action IO (Maybe Document)
+findOrderById "0" = return Nothing
 findOrderById i = findOne (select ["_id" =: (read i :: B.ObjectId)] "orders")
 
 findAllOrders :: T.Text -> Action IO [Document]
-findAllOrders a = rest =<< find (select ["address" =: a] "orders") {sort = ["timestamp" =: (negate 1 :: Int)]}
+findAllOrders a =
+  rest =<<
+  find
+    (select ["address" =: a] "orders")
+      {sort = ["timestamp" =: (negate 1 :: Int)]}
 
 deleteOrder :: String -> Action IO ()
 deleteOrder i = deleteOne (select ["_id" =: (read i :: B.ObjectId)] "orders")