add service monad (with built-in logging)

2 files changed, 15 insertions, 1 deletions

diff --git a/lib/Server/GTFS_RT.hs b/lib/Server/GTFS_RT.hs
index e2b23e0..85ea8cd 100644
--- a/lib/Server/GTFS_RT.hs
+++ b/lib/Server/GTFS_RT.hs
@@ -65,6 +65,7 @@ import           Servant.API                                ((:<|>) (..))
 import           Servant.Server                             (Handler (Handler),
                                                              Server)
 
+import           Server.Util                                (Service)
 
 uuidUtf8 :: UUID.UUID -> Utf8
 uuidUtf8 = Utf8 . fromStrict . UUID.toASCIIBytes
@@ -86,7 +87,7 @@ toStupidDate date = toUtf8
 toStupidTime :: UTCTime -> Word64
 toStupidTime = fromIntegral . systemSeconds . utcToSystemTime
 
-gtfsRealtimeServer :: GTFS -> Pool SqlBackend -> Server GtfsRealtimeAPI
+gtfsRealtimeServer :: GTFS -> Pool SqlBackend -> Service GtfsRealtimeAPI
 gtfsRealtimeServer gtfs dbpool = handleServiceAlerts :<|> handleTripUpdates :<|> handleVehiclePositions
   where handleServiceAlerts = runSql dbpool $ do
             -- TODO filter: only select current & future days
diff --git a/lib/Server/Util.hs b/lib/Server/Util.hs
new file mode 100644
index 0000000..45c2477
--- /dev/null
+++ b/lib/Server/Util.hs
@@ -0,0 +1,13 @@
+
+
+-- | mostly the monad the service runs in
+module Server.Util (Service, ServiceM, runService) where
+
+import           Control.Monad.Logger (LoggingT, runStderrLoggingT)
+import           Servant              (Handler, ServerT)
+
+type ServiceM  = LoggingT Handler
+type Service api = ServerT api ServiceM
+
+runService :: ServiceM a -> Handler a
+runService = runStderrLoggingT