add schema version

common/src/Version.hs

@@ -0,0 +1,36 @@
+module Version
+  ( Version (..),
+    versionToString,
+    versionFromText,
+    versionFromString,
+  )
+where
+
+import Data.Aeson qualified as A
+import Data.Aeson.Types qualified as A
+import Data.List
+import Data.List.Split
+import Data.Text qualified as T
+
+data Version = Version Int Int Int
+  deriving (Show, Eq)
+
+instance A.ToJSON Version where
+  toJSON =
+    A.toJSON . versionToString
+
+instance A.FromJSON Version where
+  parseJSON (A.String (versionFromText -> Just version)) = pure version
+  parseJSON v = A.typeMismatch "version" v
+
+versionToString :: Version -> String
+versionToString (Version major minor patch) =
+  intercalate "." (map show [major, minor, patch])
+
+versionFromString :: String -> Maybe Version
+versionFromString (map read . splitOn "." -> [major, minor, patch]) =
+  Just (Version major minor patch)
+versionFromString _ = Nothing
+
+versionFromText :: T.Text -> Maybe Version
+versionFromText = versionFromString . T.unpack