fix UTCTime serialization

1 files changed, 19 insertions, 5 deletions

diff --git a/app/Issue.hs b/app/Issue.hs
index c9d18f8..256947b 100644
--- a/app/Issue.hs
+++ b/app/Issue.hs
@@ -3,17 +3,20 @@
 {-# LANGUAGE DisambiguateRecordFields #-}
 {-# LANGUAGE OverloadedRecordDot #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
 
 module Issue (Issue (..), Provenance (..), fromMatch, id) where
 
-import Data.Binary (Binary, get, put)
+import Data.Binary (Binary, Put, get, put)
 import Data.ByteString.Lazy (toStrict)
+import Data.Fixed (Pico)
 import Data.Function ((&))
 import Data.List (find, foldl')
 import Data.Text (Text)
 import Data.Text qualified as T
 import Data.Text.Encoding (decodeUtf8)
-import Data.Time.Clock (UTCTime)
+import Data.Time.Calendar (Day (..), toModifiedJulianDay)
+import Data.Time.Clock (DiffTime, UTCTime (..), picosecondsToDiffTime)
 import GHC.Generics (Generic)
 import Issue.Tag (Tag (..))
 import Issue.Tag qualified as I
@@ -46,10 +49,21 @@ data Provenance = Provenance
   }
   deriving (Show, Generic, Binary)
 
+-- XXX These are taken from `Data.Binary.Orphans` [1]. I cannot get importing
+-- the instance from the package to work.. so we use `-fno-warn-orphans` here.
+--
+-- [1] https://hackage.haskell.org/package/binary-orphans-0.1.5.1/docs/src/Data-Binary-Orphans.html#line-132
 instance Binary UTCTime where
-  -- TODO Serialize UTCTime using POSIX time stamps
-  put = put . show
-  get = fmap read get
+  get = UTCTime <$> get <*> get
+  put (UTCTime d dt) = put d >> put dt
+
+instance Binary Day where
+  get = fmap ModifiedJulianDay get
+  put = put . toModifiedJulianDay
+
+instance Binary DiffTime where
+  get = fmap picosecondsToDiffTime get
+  put = (put :: Pico -> Put) . realToFrac
 
 id :: Issue -> Maybe String
 id issue =