refactor: refactor project route for ZIO HTTP (#2338)

Co-authored-by: Christian Kleinbölting <christian.kleinboelting@dasch.swiss>
Co-authored-by: Balduin Landolt <33053745+BalduinLandolt@users.noreply.github.com>
Co-authored-by: Marcin Procyk <marcin.procyk@dasch.swiss>

webapi/src/main/scala/org/knora/webapi/core/HttpServerZ.scala

@@ -0,0 +1,27 @@
+/*
+ * Copyright © 2021 - 2022 Swiss National Data and Service Center for the Humanities and/or DaSCH Service Platform contributors.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.knora.webapi.core
+import zhttp.service.Server
+import zio.ZLayer
+import zio._
+
+import org.knora.webapi.config.AppConfig
+import org.knora.webapi.routing.admin.ProjectsRouteZ
+
+object HttpServerZ {
+
+  val layer: ZLayer[AppRouter & AppConfig & State & ProjectsRouteZ, Nothing, Unit] =
+    ZLayer {
+      for {
+        appConfig     <- ZIO.service[AppConfig]
+        projectsRoute <- ZIO.service[ProjectsRouteZ]
+        r              = projectsRoute.route
+        port           = appConfig.knoraApi.externalZioPort
+        _             <- Server.start(port, r).forkDaemon
+        _             <- ZIO.logInfo(">>> Acquire ZIO HTTP Server <<<")
+      } yield ()
+    }
+}

webapi/src/main/scala/org/knora/webapi/core/LayersLive.scala

@@ -11,6 +11,7 @@ import zio.ZLayer
 import org.knora.webapi.auth.JWTService
 import org.knora.webapi.config.AppConfig
 import org.knora.webapi.routing.ApiRoutes
+import org.knora.webapi.routing.admin.ProjectsRouteZ
 import org.knora.webapi.store.cache.CacheServiceManager
 import org.knora.webapi.store.cache.api.CacheService
 import org.knora.webapi.store.cache.impl.CacheServiceInMemImpl
@@ -55,13 +56,14 @@ object LayersLive {
       CacheServiceManager.layer,
       CacheServiceInMemImpl.layer,
       HttpServer.layer,
-      HttpServerWithZIOHttp.layer, // this is the new ZIO HTTP server layer
+      HttpServerZ.layer, // this is the new ZIO HTTP server layer
       IIIFServiceManager.layer,
       IIIFServiceSipiImpl.layer,
       JWTService.layer,
       RepositoryUpdater.layer,
       State.layer,
       TriplestoreServiceManager.layer,
-      TriplestoreServiceHttpConnectorImpl.layer
+      TriplestoreServiceHttpConnectorImpl.layer,
+      ProjectsRouteZ.layer
     )
 }

webapi/src/main/scala/org/knora/webapi/http/handler/ExceptionHandlerZ.scala

@@ -0,0 +1,58 @@
+/*
+ * Copyright © 2021 - 2022 Swiss National Data and Service Center for the Humanities and/or DaSCH Service Platform contributors.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.knora.webapi.http.handler
+
+import spray.json._
+import zhttp.http.Http
+import zhttp.http.Response
+
+import dsp.errors.RequestRejectedException
+import org.knora.webapi.config.AppConfig
+import org.knora.webapi.http.status.ApiStatusCodesZ
+
+/**
+ * Migrated from [[org.knora.webapi.http.handler.KnoraExceptionHandler]]
+ */
+object ExceptionHandlerZ {
+  private val GENERIC_INTERNAL_SERVER_ERROR_MESSAGE =
+    "The request could not be completed because of an internal server error."
+
+  def exceptionToJsonHttpResponseZ(ex: Throwable, appConfig: AppConfig): Http[Any, Nothing, Any, Response] = {
+
+    // Get the HTTP status code that corresponds to the exception.
+    val httpStatus = ApiStatusCodesZ.fromExceptionZ(ex)
+
+    // Generate an HTTP response containing the error message ...
+    val responseFields: Map[String, JsValue] = Map(
+      "error" -> JsString(makeClientErrorMessage(ex, appConfig))
+    )
+
+    val json = JsObject(responseFields).compactPrint
+
+    // ... and the HTTP status code.
+    Http.response(Response.json(json).setStatus(httpStatus))
+
+  }
+
+  /**
+   * Given an exception, returns an error message suitable for clients.
+   *
+   * @param ex        the exception.
+   * @param appConfig the application's configuration.
+   * @return an error message suitable for clients.
+   */
+  private def makeClientErrorMessage(ex: Throwable, appConfig: AppConfig): String =
+    ex match {
+      case rre: RequestRejectedException => rre.toString
+
+      case other =>
+        if (appConfig.showInternalErrors) {
+          other.toString
+        } else {
+          GENERIC_INTERNAL_SERVER_ERROR_MESSAGE
+        }
+    }
+}

webapi/src/main/scala/org/knora/webapi/http/status/ApiStatusCodesZ.scala

@@ -0,0 +1,50 @@
+/*
+ * Copyright © 2021 - 2022 Swiss National Data and Service Center for the Humanities and/or DaSCH Service Platform contributors.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.knora.webapi.http.status
+
+import zhttp.http.Status
+
+import dsp.errors._
+import org.knora.webapi.store.triplestore.errors.TriplestoreTimeoutException
+
+/**
+ * Migrated from [[org.knora.webapi.http.status.ApiStatusCodes]]
+ *
+ * The possible values for the HTTP status code that is returned as part of each Knora API v2 response.
+ */
+object ApiStatusCodesZ {
+
+  /**
+   * Converts an exception to a suitable HTTP status code.
+   *
+   * @param ex an exception.
+   * @return an HTTP status code.
+   */
+
+  def fromExceptionZ(ex: Throwable): Status =
+    ex match {
+      // Subclasses of RequestRejectedException
+      case NotFoundException(_)           => Status.NotFound
+      case ForbiddenException(_)          => Status.Forbidden
+      case BadCredentialsException(_)     => Status.Unauthorized
+      case DuplicateValueException(_)     => Status.BadRequest
+      case OntologyConstraintException(_) => Status.BadRequest
+      case EditConflictException(_)       => Status.Conflict
+      case BadRequestException(_)         => Status.BadRequest
+      case ValidationException(_, _)      => Status.BadRequest
+      case RequestRejectedException(_)    => Status.BadRequest
+      // RequestRejectedException must be the last one in this group
+
+      // Subclasses of InternalServerException
+      case UpdateNotPerformedException(_)    => Status.Conflict
+      case TriplestoreTimeoutException(_, _) => Status.GatewayTimeout
+      case InternalServerException(_)        => Status.InternalServerError
+      // InternalServerException must be the last one in this group
+
+      case _ => Status.InternalServerError
+    }
+
+}

webapi/src/main/scala/org/knora/webapi/routing/admin/ProjectsRouteZ.scala

@@ -0,0 +1,62 @@
+package org.knora.webapi.routing.admin
+
+import akka.actor.ActorRef
+import akka.pattern.ask
+import akka.util.Timeout
+import zhttp.http._
+import zio.ZIO
+import zio.ZLayer
+
+import java.net.URLDecoder
+
+import dsp.errors.BadRequestException
+import dsp.errors.InternalServerException
+import dsp.errors.KnoraException
+import dsp.errors.RequestRejectedException
+import org.knora.webapi.config.AppConfig
+import org.knora.webapi.core.AppRouter
+import org.knora.webapi.http.handler.ExceptionHandlerZ
+import org.knora.webapi.messages.admin.responder.projectsmessages.ProjectGetRequestADM
+import org.knora.webapi.messages.admin.responder.projectsmessages.ProjectGetResponseADM
+import org.knora.webapi.messages.admin.responder.projectsmessages.ProjectIdentifierADM
+import org.knora.webapi.messages.util.KnoraSystemInstances
+
+final case class ProjectsRouteZ(router: AppRouter, appConfig: AppConfig) {
+  implicit val sender: ActorRef = router.ref
+  implicit val timeout: Timeout = appConfig.defaultTimeoutAsDuration
+
+  def getProjectByIri(iri: String): ZIO[Any, KnoraException, Response] =
+    for {
+      user <- ZIO.succeed(KnoraSystemInstances.Users.SystemUser)
+      iriDecoded <-
+        ZIO
+          .attempt(URLDecoder.decode(iri, "utf-8"))
+          .orElseFail(BadRequestException(s"Failed to decode IRI $iri"))
+      iriValue <- ProjectIdentifierADM.IriIdentifier
+                    .fromString(iriDecoded)
+                    .toZIO
+      message   = ProjectGetRequestADM(identifier = iriValue, requestingUser = user)
+      response <- ZIO.fromFuture(_ => router.ref.ask(message)).map(_.asInstanceOf[ProjectGetResponseADM]).orDie
+    } yield Response.json(response.toJsValue.toString())
+
+  val route: HttpApp[Any, Nothing] =
+    (Http
+      .collectZIO[Request] {
+        // TODO : Add user authentication, make tests run with the new route
+        // Returns a single project identified through the IRI.
+        case Method.GET -> !! / "admin" / "projects" / "iri" / iri =>
+          getProjectByIri(iri)
+      })
+      .catchAll {
+        case RequestRejectedException(e) =>
+          ExceptionHandlerZ.exceptionToJsonHttpResponseZ(e, appConfig)
+        case InternalServerException(e) =>
+          ExceptionHandlerZ.exceptionToJsonHttpResponseZ(e, appConfig)
+      }
+}
+
+object ProjectsRouteZ {
+  val layer: ZLayer[AppRouter with AppConfig, Nothing, ProjectsRouteZ] = ZLayer.fromFunction { (router, config) =>
+    ProjectsRouteZ(router, config)
+  }
+}