calamity-0.5.0.0: Calamity/Internal/UnixTimestamp.hs

-- | Internal newtype for deserializing timestamps
module Calamity.Internal.UnixTimestamp (
    UnixTimestamp (..),
    unixToMilliseconds,
    millisecondsToUnix,
) where

import Calamity.Internal.Utils ()
import Control.Arrow
import Data.Aeson
import Data.Aeson.Encoding (word64)
import Data.Time
import Data.Time.Clock.POSIX
import Data.Word
import TextShow

newtype UnixTimestamp = UnixTimestamp
    { unUnixTimestamp :: UTCTime
    }
    deriving (Show) via UTCTime
    deriving (TextShow) via FromStringShow UTCTime

unixToMilliseconds :: UnixTimestamp -> Word64
unixToMilliseconds =
    unUnixTimestamp
        >>> utcTimeToPOSIXSeconds
        >>> toRational
        >>> (* 1000)
        >>> round

millisecondsToUnix :: Word64 -> UnixTimestamp
millisecondsToUnix =
    toRational
        >>> fromRational
        >>> (/ 1000)
        >>> posixSecondsToUTCTime
        >>> UnixTimestamp

instance ToJSON UnixTimestamp where
    toJSON =
        unUnixTimestamp
            >>> utcTimeToPOSIXSeconds
            >>> toRational
            >>> round
            >>> toJSON @Word64
    toEncoding =
        unUnixTimestamp
            >>> utcTimeToPOSIXSeconds
            >>> toRational
            >>> round
            >>> word64

instance FromJSON UnixTimestamp where
    parseJSON =
        withScientific "UnixTimestamp" $
            toRational
                >>> fromRational
                >>> posixSecondsToUTCTime
                >>> UnixTimestamp
                >>> pure