Job/Printer list

1 files changed, 11 insertions, 1 deletions

diff --git a/spec/src/Thermoprint/API.hs b/spec/src/Thermoprint/API.hs
index 3ffd239..5b9c266 100644
--- a/spec/src/Thermoprint/API.hs
+++ b/spec/src/Thermoprint/API.hs
@@ -7,7 +7,7 @@
 -- | A specification of an API for interacting with a set of printers
 module Thermoprint.API
        ( PrinterStatus(..)
-       , JobStatus(..)
+       , JobStatus(..), queueSort
        , PrintingError(..)
        , DraftTitle
        , Range(..), contains
@@ -25,6 +25,7 @@ import           Data.Aeson
 
 import           Data.Monoid
 import           Data.Maybe
+import           Data.Function (on)
 
 import           Data.Set (Set)
 import           Data.Map (Map)
@@ -70,6 +71,15 @@ data JobStatus = Queued PrinterId
                | Failed PrintingError
                deriving (Generic, Show, FromJSON, ToJSON)
 
+queueSort :: JobStatus -> JobStatus -> Ordering
+-- ^ Sort 'JobStatus' by their qualitative position in a printers queue
+queueSort = compare `on` index
+  where
+    index (Queued _) = -1
+    index (Printing _) = 0
+    index Done = 1
+    index (Failed _) = 1
+
 deriving instance Generic EncodingException
 deriving instance NFData EncodingException
 deriving instance FromJSON EncodingException