use OsPath instead of FilePath in easy cases

this is still far from being supported by most libraries, but does make
it possible to remove some uses of String (though most times, there is a
conversion back to String later).

Note that using the default.nix now only works on nixpkgs-unstable for a
bit; using the newer filepath package on stable leads to broken other packages.

2 files changed, 18 insertions, 6 deletions

diff --git a/lib/Server.hs b/lib/Server.hs
index 15027b3..3fc2c5a 100644
--- a/lib/Server.hs
+++ b/lib/Server.hs
@@ -36,7 +36,6 @@ import           Prometheus                  (Info (Info), exportMetricsAsText,
                                               gauge, register)
 import           Prometheus.Metric.GHC       (ghcMetrics)
 import           Servant                     (Application, err401, serve,
-                                              serveDirectoryFileServer,
                                               throwError)
 import           Servant.API                 ((:<|>) (..))
 import           Servant.Server              (hoistServer)
@@ -47,7 +46,8 @@ import           Server.GTFS_RT              (gtfsRealtimeServer)
 import           Server.Ingest               (handleTrackerRegister,
                                               handleTrainPing, handleWS)
 import           Server.Subscribe            (handleSubscribe)
-import           Server.Util                 (Service, runLogging, runService)
+import           Server.Util                 (Service, runLogging, runService,
+                                              serveDirectoryFileServer)
 import           System.IO.Unsafe            (unsafePerformIO)
 import           Yesod                       (toWaiAppPlain)
 
diff --git a/lib/Server/Util.hs b/lib/Server/Util.hs
index 290b9c5..b519a86 100644
--- a/lib/Server/Util.hs
+++ b/lib/Server/Util.hs
@@ -1,7 +1,7 @@
 {-# LANGUAGE BlockArguments  #-}
 {-# LANGUAGE RecordWildCards #-}
 -- | mostly the monad the service runs in
-module Server.Util (Service, ServiceM, runService, sendErrorMsg, secondsNow, utcToSeconds, runLogging, getTzseries) where
+module Server.Util (Service, ServiceM, runService, sendErrorMsg, secondsNow, utcToSeconds, runLogging, getTzseries, serveDirectoryFileServer) where
 
 import           Config                              (LoggingConfig (..),
                                                       ServerConfig (..))
@@ -27,14 +27,18 @@ import           Data.Time                           (Day, UTCTime (..),
 import           Data.Time.LocalTime.TimeZone.Olson  (getTimeZoneSeriesFromOlsonFile)
 import           Data.Time.LocalTime.TimeZone.Series (TimeZoneSeries)
 import           Fmt                                 ((+|), (|+))
+import           GHC.IO                              (unsafePerformIO)
 import           GHC.IO.Exception                    (IOException (IOError))
 import           GTFS                                (Seconds (..))
 import           Prometheus                          (MonadMonitor (doIO))
+import qualified Servant
 import           Servant                             (Handler, ServerError,
                                                       ServerT, err404, errBody,
                                                       errHeaders, throwError)
-import           System.FilePath                     ((</>))
 import           System.IO                           (stderr)
+import           System.OsPath                       (OsPath, decodeFS,
+                                                      decodeUtf, encodeUtf,
+                                                      (</>))
 import           System.Process.Extra                (callProcess)
 
 type ServiceM  = LoggingT (ReaderT LoggingConfig Handler)
@@ -87,5 +91,13 @@ utcToSeconds time day =
   Seconds $ round $ nominalDiffTimeToSeconds $ diffUTCTime time (UTCTime day 0)
 
 getTzseries :: ServerConfig -> Text -> IO TimeZoneSeries
-getTzseries settings tzname = getTimeZoneSeriesFromOlsonFile
-        (serverConfigZoneinfoPath settings </> T.unpack tzname)
+getTzseries settings tzname = do
+  suffix <- encodeUtf (T.unpack tzname)
+  -- TODO: submit a patch to timezone-olson making it accept OsPath
+  legacyPath <- decodeFS (serverConfigZoneinfoPath settings </> suffix)
+  getTimeZoneSeriesFromOlsonFile legacyPath
+
+-- TODO: patch servant / wai to use OsPath?
+serveDirectoryFileServer :: OsPath -> ServerT Servant.Raw m
+serveDirectoryFileServer =
+  Servant.serveDirectoryFileServer . unsafePerformIO . decodeUtf