package org.act

import akka.actor.ActorSystem
import akka.http.scaladsl.Http
import akka.http.scaladsl.marshalling.ToResponseMarshallable
import akka.http.scaladsl.server.Directives._
import akka.kafka.ConsumerSettings
import akka.kafka.Subscriptions.assignment
import akka.kafka.scaladsl.Consumer
import akka.stream.ActorMaterializer
import de.heikoseeberger.akkasse.ServerSentEvent
import org.apache.kafka.clients.consumer.ConsumerConfig
import org.apache.kafka.common.TopicPartition
import org.apache.kafka.common.serialization.StringDeserializer

import scala.concurrent.duration.{Duration, MINUTES}
import scala.io.StdIn

object Server extends App {
  implicit val system = ActorSystem("server")
  implicit val materialiser = ActorMaterializer()
  implicit val executionContext = system.dispatcher

  val consumerSettings: ConsumerSettings[String, String] = ConsumerSettings(
    system,
    new StringDeserializer,
    new StringDeserializer
  )
    .withBootstrapServers("kafka-0.broker:9092")
    .withGroupId("g1")
    .withProperty(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest")


  val route = path("all") {
    import de.heikoseeberger.akkasse.EventStreamMarshalling._

    get {
      complete(ToResponseMarshallable(Consumer.plainSource(
        consumerSettings,
        assignment(new TopicPartition("crimes", 0)))
        .map(record => record.value())
        .map(value => ServerSentEvent(value, "crime"))
        .keepAlive(Duration(20, MINUTES), () => ServerSentEvent.Heartbeat)))
    }
  }

  val serverBinding = Http().bindAndHandle(route, "localhost", 8091)
  StdIn.readLine()
  serverBinding
    .flatMap(_.unbind())
    .onComplete(_ => system.terminate())
}