path: root/src/main/scala/com/drivergrp/core/rest.scala

package com.drivergrp.core

import akka.actor.ActorSystem
import akka.http.scaladsl.Http
import akka.http.scaladsl.model.Uri.Path
import akka.http.scaladsl.model.{HttpRequest, HttpResponse}
import akka.http.scaladsl.server.PathMatcher.Matched
import akka.http.scaladsl.server.{Directive, _}
import akka.http.scaladsl.util.FastFuture._
import akka.stream.ActorMaterializer
import akka.util.Timeout
import com.drivergrp.core.logging.Logger
import com.drivergrp.core.stats.Stats
import com.drivergrp.core.time.{Time, TimeRange}
import com.drivergrp.core.time.provider.TimeProvider
import com.github.swagger.akka.model._
import com.github.swagger.akka.{HasActorSystem, SwaggerHttpService}
import com.typesafe.config.Config
import spray.json.{DeserializationException, JsNumber, JsObject, JsString, JsValue, RootJsonFormat}

import scala.concurrent.duration._
import scala.concurrent.{ExecutionContext, Future}
import scala.language.postfixOps
import scala.util.{Failure, Success, Try}
import scalaz.{Failure => _, Success => _, _}


object rest {

  trait RestService {
    def sendRequest(request: HttpRequest): Future[HttpResponse]
  }

  class AkkaHttpRestService(actorSystem: ActorSystem) extends RestService {
    protected implicit val materializer = ActorMaterializer()(actorSystem)

    def sendRequest(request: HttpRequest): Future[HttpResponse] =
      Http()(actorSystem).singleRequest(request)(materializer)
  }

  class ProxyRestService(actorSystem: ActorSystem, log: Logger, stats: Stats,
                         time: TimeProvider, executionContext: ExecutionContext)
    extends AkkaHttpRestService(actorSystem) {

    protected implicit val timeout = Timeout(5 seconds)

    override def sendRequest(request: HttpRequest): Future[HttpResponse] = {

      log.audit(s"Sending to ${request.uri} request $request")

      val requestTime = time.currentTime()
      val response = super.sendRequest(request)

      response.onComplete {
        case Success(_) =>
          val responseTime = time.currentTime()
          log.audit(s"Response from ${request.uri} to request $request is successful")
          stats.recordStats(Seq("request", request.uri.toString, "success"), TimeRange(requestTime, responseTime), 1)

        case Failure(t) =>
          val responseTime = time.currentTime()
          log.audit(s"Failed to receive response from ${request.uri} to request $request")
          log.error(s"Failed to receive response from ${request.uri} to request $request", t)
          stats.recordStats(Seq("request", request.uri.toString, "fail"), TimeRange(requestTime, responseTime), 1)
      } (executionContext)

      response
    }
  }

  object basicFormats {

    def IdInPath[T]: PathMatcher1[Id[T]] =
      PathMatcher("""[+-]?\d*""".r) flatMap { string ⇒
        try Some(Id[T](string.toLong)) catch { case _: IllegalArgumentException ⇒ None }
      }

    implicit def idFormat[T] = new RootJsonFormat[Id[T]] {
      def write(id: Id[T]) = JsNumber(id)

      def read(value: JsValue) = value match {
        case JsNumber(id) => Id[T](id.toLong)
        case _ => throw new DeserializationException("Id expects number")
      }
    }

    def NameInPath[T]: PathMatcher1[Name[T]] = new PathMatcher1[Name[T]] {
      def apply(path: Path) = Matched(Path.Empty, Tuple1(Name[T](path.toString)))
    }

    implicit def nameFormat[T] = new RootJsonFormat[Name[T]] {
      def write(name: Name[T]) = JsString(name)

      def read(value: JsValue): Name[T] = value match {
        case JsString(name) => Name[T](name)
        case _ => throw new DeserializationException("Name expects string")
      }
    }

    def TimeInPath[T]: PathMatcher1[Time] =
      PathMatcher("""[+-]?\d*""".r) flatMap { string ⇒
        try Some(Time(string.toLong)) catch { case _: IllegalArgumentException ⇒ None }
      }

    implicit def timeFormat[T] = new RootJsonFormat[Time] {
      def write(time: Time) = JsObject("timestamp" -> JsNumber(time.millis))

      def read(value: JsValue): Time = value match {
        case JsObject(fields) =>
          fields.get("timestamp").flatMap {
            case JsNumber(millis) => Some(Time(millis.toLong))
            case _ => None
          }.getOrElse(throw new DeserializationException("Time expects number"))
        case _ => throw new DeserializationException("Time expects number")
      }
    }
  }

  trait OptionTDirectives {

    /**
      * "Unwraps" a `OptionT[Future, T]` and runs the inner route after future
      * completion with the future's value as an extraction of type `Try[T]`.
      */
    def onComplete[T](optionT: OptionT[Future, T]): Directive1[Try[Option[T]]] =
      Directive { inner ⇒ ctx ⇒
        import ctx.executionContext
        optionT.run.fast.transformWith(t ⇒ inner(Tuple1(t))(ctx))
      }
  }


  import scala.reflect.runtime.universe._

  class Swagger(override val actorSystem: ActorSystem,
                override val apiTypes: Seq[Type],
                val config: Config) extends SwaggerHttpService with HasActorSystem {

    val materializer = ActorMaterializer()(actorSystem)

    override val host = "localhost:8080" //the url of your api, not swagger's json endpoint
    override val basePath = config.getString("swagger.basePath")
    override val apiDocsPath = config.getString("swagger.docsPath")

    override val info = Info(
      config.getString("swagger.apiInfo.description"),
      config.getString("swagger.apiVersion"),
      config.getString("swagger.apiInfo.title"),
      config.getString("swagger.apiInfo.termsOfServiceUrl"),
      contact = Some(Contact(
        config.getString("swagger.apiInfo.contact.name"),
        config.getString("swagger.apiInfo.contact.url"),
        config.getString("swagger.apiInfo.contact.email")
      )),
      license = Some(License(
        config.getString("swagger.apiInfo.license"),
        config.getString("swagger.apiInfo.licenseUrl")
      )),
      vendorExtensions = Map())

    def swaggerUI = get {
      pathPrefix("") {
        pathEndOrSingleSlash {
          getFromResource("swagger-ui/index.html")
        }
      } ~ getFromResourceDirectory("swagger-ui")
    }
  }
}