1 files changed, 55 insertions, 0 deletions
diff --git a/users/Profpatsch/my-prelude/src/Seconds.hs b/users/Profpatsch/my-prelude/src/Seconds.hs
new file mode 100644
index 000000000000..8d05f30be8c3
--- /dev/null
+++ b/users/Profpatsch/my-prelude/src/Seconds.hs
@@ -0,0 +1,55 @@
+module Seconds where
+
+import Data.Aeson (FromJSON)
+import Data.Aeson qualified as Json
+import Data.Aeson.Types (FromJSON (parseJSON))
+import Data.Scientific
+import Data.Time (NominalDiffTime)
+import FieldParser
+import FieldParser qualified as Field
+import GHC.Natural (naturalToInteger)
+import PossehlAnalyticsPrelude
+
+-- | A natural number of seconds.
+newtype Seconds = Seconds {unSeconds :: Natural}
+  deriving stock (Eq, Show)
+
+-- | Parse a decimal number as a number of seconds
+textToSeconds :: FieldParser Text Seconds
+textToSeconds = Seconds <$> Field.decimalNatural
+
+scientificToSeconds :: FieldParser Scientific Seconds
+scientificToSeconds =
+  ( Field.boundedScientificIntegral @Int "Number of seconds"
+      >>> Field.integralToNatural
+  )
+    & rmap Seconds
+
+-- Microseconds, represented internally with a 64 bit Int
+newtype MicrosecondsInt = MicrosecondsInt {unMicrosecondsInt :: Int}
+  deriving stock (Eq, Show)
+
+-- | Try to fit a number of seconds into a MicrosecondsInt
+secondsToMicrosecondsInt :: FieldParser Seconds MicrosecondsInt
+secondsToMicrosecondsInt =
+  lmap
+    (\sec -> naturalToInteger sec.unSeconds * 1_000_000)
+    (Field.bounded "Could not fit into an Int after multiplying with 1_000_000 (seconds to microseconds)")
+    & rmap MicrosecondsInt
+
+secondsToNominalDiffTime :: Seconds -> NominalDiffTime
+secondsToNominalDiffTime sec =
+  sec.unSeconds
+    & naturalToInteger
+    & fromInteger @NominalDiffTime
+
+instance FromJSON Seconds where
+  parseJSON = Field.toParseJSON jsonNumberToSeconds
+
+-- | Parse a json number as a number of seconds.
+jsonNumberToSeconds :: FieldParser' Error Json.Value Seconds
+jsonNumberToSeconds = Field.jsonNumber >>> scientificToSeconds
+
+-- | Return the number of seconds in a week
+secondsInAWeek :: Seconds
+secondsInAWeek = Seconds (3600 * 24 * 7)