syntax

import meteor.syntax._
import meteor.codec._

case class Author(
 names: String,
 age: Int
)

case class Book(
 name: String,
 author: Author,
 coAuthor: Option[Author]
)

implicit val encoderForAuthor: Encoder[Author] = Encoder.instance { obj =>
 Map(
   "names" -> obj.names.asAttributeValue,
   "age" -> obj.age.asAttributeValue
 ).asAttributeValue
}

implicit val encoderForBook: Encoder[Book] = Encoder.instance { obj =>
 Map(
   "name" -> obj.names.asAttributeValue,
   "author" -> obj.age.asAttributeValue,
   "coAuthor" -> obj.age.asAttributeValue,
 ).asAttributeValue
}

implicit val decoderForAuthor: Decoder[Author] = Decoder.instance { av =>
 for {
   names <- av.getAs[String]("names")
   age <- av.getAs[Int]("age")
 } yield Author(names, age)
}

implicit val decoderForBook: Decoder[Book] = Decoder.instance { av =>
 for {
   name <- av.getAs[String]("name")
   author <- av.getAs[Author]("author")
   coAuthor <- av.getOpt[Author]("coAuthor")
 } yield Book(name, author, coAuthor)
}