import zio.json._

@jsonDiscriminator("type")
sealed trait Animal
object Animal {
  @jsonHint("dog")
  case class Dog(name: String) extends Animal
  object Dog {
    implicit val dogCodec: JsonCodec[Dog] = DeriveJsonCodec.gen
  }
  
  @jsonHint("cat")
  case class Cat(name: String, weight: Double) extends Animal

  implicit val animalCodec: JsonCodec[Animal] = DeriveJsonCodec.gen
}

import zio.json._
import zio.test._

object AnimalCodecSpec extends ZIOSpecDefault {
  override def spec: Spec[TestEnvironment, Any] =
    test("this would fail, as it ignores the discriminator") {
      val json    = """{"type":"cat","name":"Kitty", "weight": 8}"""
      val decoded = json.fromJson[Dog]
      assertTrue(decoded.is(_.left.anything)) // decoded == Right(Dog(Kitty))
    }
}

@jsonDiscriminator("type")
sealed trait Animal2

object Animal2 {
  @jsonDiscriminator("type")
  sealed trait Dog extends Animal2 { // extra sealed trait needed as a workaround
    val name: String
  }

  @jsonHint("dog")
  case class DogImpl(name: String) extends Dog
  object Dog {
    implicit val dogCodec: JsonCodec[Dog] = DeriveJsonCodec.gen
  }

  @jsonHint("cat")
  case class Cat(name: String, weight: Double) extends Animal2

  implicit val animalCodec: JsonCodec[Animal2] = DeriveJsonCodec.gen
}

object Animal2CodecSpec extends ZIOSpecDefault {
  override def spec: Spec[TestEnvironment, Any] =
    test("this would success, as it honors the discriminator") {
      val json    = """{"type":"cat","name":"Kitty", "weight": 8}"""
      val decoded = json.fromJson[Animal2.Dog]
      assertTrue(decoded.is(_.left.anything)) // decoded == Left((invalid disambiguator))
    }
}