Circe Codecs for Map[String, Any]

import io.circe.Decoder.Result
import io.circe._

trait Codecs {
  implicit val mapEncoder = new Encoder[Map[String, Any]] {
    override def apply(obj: Map[String, Any]): Json = {
      def convert(arg: Any): Json = {
        arg match {
          case x: Int => Json.fromInt(x)
          case x: Long => Json.fromLong(x)
          case x: Float => Json.fromFloat(x).getOrElse(Json.fromInt(0))
          case x: Double => Json.fromDouble(x).getOrElse(Json.fromInt(0))
          case x: String => Json.fromString(x)
          case x: Boolean => Json.fromBoolean(x)
          case x: Map[String @unchecked, Any @unchecked] => Json.fromFields(x mapValues convert)
          case x: Iterable[Any] => Json.fromValues(x map convert)
          case x: Any => Json.fromString(x.toString)
        }
      }

      Json.fromFields(obj mapValues convert)
    }
  }

  implicit val mapDecoder = new Decoder[Map[String, Any]] {
    import cats.implicits._
    override def apply(c: HCursor): Result[Map[String, Any]] = {
      val keys = c.keys.getOrElse(Nil).toList
      for {
        jsonList <- keys traverse {key => c.downField(key).as[Json]}
      } yield keys.zip(jsonList).toMap
    }
  }
}