import com.twitter.finagle.Http
import com.twitter.util.{Await, Future}
import io.finch._
import io.finch.syntax._
import io.finch.circe.accumulating._
import io.circe._
import io.circe.generic.auto._

case class RequestBody(foo: Boolean, bar: Int)
case class FakeResponse()

object Main extends App {
  implicit val encodeException: Encoder[Exception] = Encoder.instance({
    case e: io.finch.Errors => encodeErrorList(e.errors.toList)
    case e: io.finch.Error =>
      e.getCause match {
        case e: io.circe.Errors => encodeErrorList(e.errors.toList)
        case err => Json.obj("message" -> Json.fromString(err.getMessage))
      }
    case e: Exception => Json.obj("message" -> Json.fromString(s"Oh noes! ${e.getMessage}"))
  })

  def encodeErrorList(es: List[Exception]): Json = {
    val messages = es.map(x => Json.fromString(x.getMessage))
    Json.obj("errors" -> Json.arr(messages: _*))
  }

  def fakeServiceMethod(requestBody: RequestBody): Future[Output[FakeResponse]] = Future.value(Ok(FakeResponse()))

  val fooEndpoint: Endpoint[FakeResponse] = post("foo" :: jsonBody[RequestBody])(fakeServiceMethod _)

  Await.ready(Http.server.serve(":8080", fooEndpoint.toServiceAs[Application.Json]))
}