CirceDateTimeUtil.scala

import java.time.ZonedDateTime
import java.time.format.DateTimeFormatter

import cats.implicits._
import io.circe.{ Codec, Decoder, Encoder }

// circe codec for serializing ZonedDateTime into JSON
object  CirceDateTimeUtil {
  
  val dateFormatter: DateTimeFormatter                 = DateTimeFormatter.ISO_ZONED_DATE_TIME
  private lazy val dateEncoder: Encoder[ZonedDateTime] = Encoder.encodeString.contramap[ZonedDateTime](_.format(dateFormatter))
  private lazy val dateDecoder: Decoder[ZonedDateTime] = Decoder.decodeString.emap[ZonedDateTime] { str =>
    Either.catchNonFatal(ZonedDateTime.parse(str, dateFormatter)).leftMap(_.getMessage)
  }
  
  implicit lazy val zonedDateTimeCodec: Codec[ZonedDateTime] = Codec.from(dateDecoder, dateEncoder)
}