Improve coverage of xNF simulator

Also refactor to make it possible.

Change-Id: I6da6d3f33e57c524a7e353ecebd3e045d8ceed2a
Issue-ID: DCAEGEN2-739
Signed-off-by: Piotr Jaszczyk <piotr.jaszczyk@nokia.com>

11 files changed, 553 insertions, 205 deletions

diff --git a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/HttpServer.kt b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/HttpServer.kt
deleted file mode 100644
index 02e6ee72..00000000
--- a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/HttpServer.kt
+++ /dev/null
@@ -1,102 +0,0 @@
-/*
- * ============LICENSE_START=======================================================
- * dcaegen2-collectors-veshv
- * ================================================================================
- * Copyright (C) 2018 NOKIA
- * ================================================================================
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- * ============LICENSE_END=========================================================
- */
-package org.onap.dcae.collectors.veshv.simulators.xnf.impl
-
-import arrow.effects.IO
-import org.onap.dcae.collectors.veshv.utils.logging.Logger
-import org.onap.dcae.collectors.veshv.ves.message.generator.api.MessageGenerator
-import org.onap.dcae.collectors.veshv.ves.message.generator.api.MessageParametersParser
-import org.onap.dcae.collectors.veshv.ves.message.generator.api.MessageParametersParser.Companion.INSTANCE
-import ratpack.handling.Chain
-import ratpack.handling.Context
-import ratpack.server.RatpackServer
-import ratpack.server.ServerConfig
-import reactor.core.scheduler.Schedulers
-import javax.json.Json
-
-/**
- * @author Jakub Dudycz <jakub.dudycz@nokia.com>
- * @since June 2018
- */
-internal class HttpServer(private val vesClient: XnfSimulator,
-                          private val messageParametersParser: MessageParametersParser = INSTANCE) {
-
-    fun start(port: Int): IO<RatpackServer> = IO {
-        RatpackServer.start { server ->
-            server.serverConfig(ServerConfig.embedded().port(port))
-                    .handlers(this::configureHandlers)
-        }
-    }
-
-    private fun configureHandlers(chain: Chain) {
-        chain
-                .post("simulator/sync") { ctx ->
-                    ctx.request.body
-                            .map { Json.createReader(it.inputStream).readArray() }
-                            .map { messageParametersParser.parse(it) }
-                            .map { MessageGenerator.INSTANCE.createMessageFlux(it) }
-                            .map { vesClient.sendIo(it) }
-                            .map { it.unsafeRunSync() }
-                            .onError { handleException(it, ctx) }
-                            .then { sendAcceptedResponse(ctx) }
-                }
-                .post("simulator/async") { ctx ->
-                    ctx.request.body
-                            .map { Json.createReader(it.inputStream).readArray() }
-                            .map { messageParametersParser.parse(it) }
-                            .map { MessageGenerator.INSTANCE.createMessageFlux(it) }
-                            .map { vesClient.sendRx(it) }
-                            .map { it.subscribeOn(Schedulers.elastic()).subscribe() }
-                            .onError { handleException(it, ctx) }
-                            .then { sendAcceptedResponse(ctx) }
-                }
-                .get("healthcheck") { ctx ->
-                    ctx.response.status(STATUS_OK).send()
-                }
-    }
-
-    private fun sendAcceptedResponse(ctx: Context) {
-        ctx.response
-                .status(STATUS_OK)
-                .send(CONTENT_TYPE_APPLICATION_JSON, Json.createObjectBuilder()
-                        .add("response", "Request accepted")
-                        .build()
-                        .toString())
-    }
-
-    private fun handleException(t: Throwable, ctx: Context) {
-        logger.warn("Failed to process the request - ${t.localizedMessage}")
-        logger.debug("Exception thrown when processing the request", t)
-        ctx.response
-                .status(STATUS_BAD_REQUEST)
-                .send(CONTENT_TYPE_APPLICATION_JSON, Json.createObjectBuilder()
-                        .add("response", "Request was not accepted")
-                        .add("exception", t.localizedMessage)
-                        .build()
-                        .toString())
-    }
-
-    companion object {
-        private val logger = Logger(HttpServer::class)
-        const val STATUS_OK = 200
-        const val STATUS_BAD_REQUEST = 400
-        const val CONTENT_TYPE_APPLICATION_JSON = "application/json"
-    }
-}
diff --git a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/XnfSimulator.kt b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/XnfSimulator.kt
index e8a474d0..558bd1c1 100644
--- a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/XnfSimulator.kt
+++ b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/XnfSimulator.kt
@@ -19,98 +19,40 @@
  */
 package org.onap.dcae.collectors.veshv.simulators.xnf.impl
 
+import arrow.core.Either
+import arrow.core.Some
+import arrow.core.Try
+import arrow.core.fix
+import arrow.core.flatMap
+import arrow.core.monad
 import arrow.effects.IO
-import io.netty.handler.ssl.ClientAuth
-import io.netty.handler.ssl.SslContext
-import io.netty.handler.ssl.SslContextBuilder
-import io.netty.handler.ssl.SslProvider
-import org.onap.dcae.collectors.veshv.domain.EndOfTransmissionMessage
-import org.onap.dcae.collectors.veshv.domain.PayloadWireFrameMessage
-import org.onap.dcae.collectors.veshv.domain.SecurityConfiguration
-import org.onap.dcae.collectors.veshv.domain.WireFrameEncoder
-import org.onap.dcae.collectors.veshv.simulators.xnf.config.SimulatorConfiguration
-import org.onap.dcae.collectors.veshv.utils.logging.Logger
-import org.reactivestreams.Publisher
-import reactor.core.publisher.Flux
-import reactor.core.publisher.Mono
-import reactor.core.publisher.ReplayProcessor
-import reactor.ipc.netty.NettyOutbound
-import reactor.ipc.netty.tcp.TcpClient
-
+import arrow.typeclasses.binding
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.adapters.VesHvClient
+import org.onap.dcae.collectors.veshv.ves.message.generator.api.MessageGenerator
+import org.onap.dcae.collectors.veshv.ves.message.generator.api.MessageParametersParser
+import org.onap.dcae.collectors.veshv.ves.message.generator.api.ParsingError
+import java.io.InputStream
+import javax.json.Json
 
 /**
- * @author Jakub Dudycz <jakub.dudycz@nokia.com>
- * @since June 2018
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since August 2018
  */
-internal class XnfSimulator(private val configuration: SimulatorConfiguration) {
-
-    private val client: TcpClient = TcpClient.builder()
-            .options { opts ->
-                opts.host(configuration.vesHost)
-                        .port(configuration.vesPort)
-                        .sslContext(createSslContext(configuration.security))
-            }
-            .build()
-
-    fun sendIo(messages: Flux<PayloadWireFrameMessage>) = IO<Unit> {
-        sendRx(messages).block()
-    }
-
-    fun sendRx(messages: Flux<PayloadWireFrameMessage>): Mono<Void> {
-        val complete = ReplayProcessor.create<Void>(1)
-        client
-                .newHandler { _, output -> handler(complete, messages, output) }
-                .doOnError {
-                    logger.info("Failed to connect to VesHvCollector on " +
-                            "${configuration.vesHost}:${configuration.vesPort}")
-                }
-                .subscribe {
-                    logger.info("Connected to VesHvCollector on " +
-                            "${configuration.vesHost}:${configuration.vesPort}")
-                }
-        return complete.then()
-    }
-
-    private fun handler(complete: ReplayProcessor<Void>,
-                        messages: Flux<PayloadWireFrameMessage>,
-                        nettyOutbound: NettyOutbound): Publisher<Void> {
-
-        val allocator = nettyOutbound.alloc()
-        val encoder = WireFrameEncoder(allocator)
-        val frames = messages
-                .map(encoder::encode)
-                .window(MAX_BATCH_SIZE)
-
-        return nettyOutbound
-                .logConnectionClosed()
-                .options { it.flushOnBoundary() }
-                .sendGroups(frames)
-                .send(Mono.just(allocator.buffer().writeByte(eotMessageByte.toInt())))
-                .then {
-                    logger.info("Messages have been sent")
-                    complete.onComplete()
-                }
-                .then()
-    }
-
-    private fun createSslContext(config: SecurityConfiguration): SslContext =
-            SslContextBuilder.forClient()
-                    .keyManager(config.cert.toFile(), config.privateKey.toFile())
-                    .trustManager(config.trustedCert.toFile())
-                    .sslProvider(SslProvider.OPENSSL)
-                    .clientAuth(ClientAuth.REQUIRE)
-                    .build()
-
-    private fun NettyOutbound.logConnectionClosed(): NettyOutbound {
-        context().onClose {
-            logger.info { "Connection to ${context().address()} has been closed" }
-        }
-        return this
-    }
-
-    companion object {
-        private val logger = Logger(XnfSimulator::class)
-        private const val MAX_BATCH_SIZE = 128
-        private const val eotMessageByte = EndOfTransmissionMessage.MARKER_BYTE
-    }
+class XnfSimulator(
+        private val vesClient: VesHvClient,
+        private val messageParametersParser: MessageParametersParser = MessageParametersParser.INSTANCE,
+        private val messageGenerator: MessageGenerator = MessageGenerator.INSTANCE) {
+
+    fun startSimulation(messageParameters: InputStream): Either<ParsingError, IO<Unit>> =
+            Either.monad<ParsingError>().binding {
+                val json = parseJsonArray(messageParameters).bind()
+                val parsed = messageParametersParser.parse(json).bind()
+                val generatedMessages = messageGenerator.createMessageFlux(parsed)
+                vesClient.sendIo(generatedMessages)
+            }.fix()
+
+    private fun parseJsonArray(jsonStream: InputStream) =
+            Try {
+                Json.createReader(jsonStream).readArray()
+            }.toEither().mapLeft { ParsingError("failed to parse JSON", Some(it)) }
 }
diff --git a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/adapters/VesHvClient.kt b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/adapters/VesHvClient.kt
new file mode 100644
index 00000000..22e47d75
--- /dev/null
+++ b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/adapters/VesHvClient.kt
@@ -0,0 +1,115 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.simulators.xnf.impl.adapters
+
+import io.netty.handler.ssl.ClientAuth
+import io.netty.handler.ssl.SslContext
+import io.netty.handler.ssl.SslContextBuilder
+import io.netty.handler.ssl.SslProvider
+import org.onap.dcae.collectors.veshv.domain.EndOfTransmissionMessage
+import org.onap.dcae.collectors.veshv.domain.PayloadWireFrameMessage
+import org.onap.dcae.collectors.veshv.domain.SecurityConfiguration
+import org.onap.dcae.collectors.veshv.domain.WireFrameEncoder
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.config.SimulatorConfiguration
+import org.onap.dcae.collectors.veshv.utils.arrow.asIo
+import org.onap.dcae.collectors.veshv.utils.logging.Logger
+import org.reactivestreams.Publisher
+import reactor.core.publisher.Flux
+import reactor.core.publisher.Mono
+import reactor.core.publisher.ReplayProcessor
+import reactor.ipc.netty.NettyOutbound
+import reactor.ipc.netty.tcp.TcpClient
+
+
+/**
+ * @author Jakub Dudycz <jakub.dudycz@nokia.com>
+ * @since June 2018
+ */
+class VesHvClient(private val configuration: SimulatorConfiguration) {
+
+    private val client: TcpClient = TcpClient.builder()
+            .options { opts ->
+                opts.host(configuration.vesHost)
+                        .port(configuration.vesPort)
+                        .sslContext(createSslContext(configuration.security))
+            }
+            .build()
+
+    fun sendIo(messages: Flux<PayloadWireFrameMessage>) =
+            sendRx(messages).then(Mono.just(Unit)).asIo()
+
+    private fun sendRx(messages: Flux<PayloadWireFrameMessage>): Mono<Void> {
+        val complete = ReplayProcessor.create<Void>(1)
+        client
+                .newHandler { _, output -> handler(complete, messages, output) }
+                .doOnError {
+                    logger.info("Failed to connect to VesHvCollector on " +
+                            "${configuration.vesHost}:${configuration.vesPort}")
+                }
+                .subscribe {
+                    logger.info("Connected to VesHvCollector on " +
+                            "${configuration.vesHost}:${configuration.vesPort}")
+                }
+        return complete.then()
+    }
+
+    private fun handler(complete: ReplayProcessor<Void>,
+                        messages: Flux<PayloadWireFrameMessage>,
+                        nettyOutbound: NettyOutbound): Publisher<Void> {
+
+        val allocator = nettyOutbound.alloc()
+        val encoder = WireFrameEncoder(allocator)
+        val frames = messages
+                .map(encoder::encode)
+                .window(MAX_BATCH_SIZE)
+
+        return nettyOutbound
+                .logConnectionClosed()
+                .options { it.flushOnBoundary() }
+                .sendGroups(frames)
+                .send(Mono.just(allocator.buffer().writeByte(eotMessageByte.toInt())))
+                .then {
+                    logger.info("Messages have been sent")
+                    complete.onComplete()
+                }
+                .then()
+    }
+
+    private fun createSslContext(config: SecurityConfiguration): SslContext =
+            SslContextBuilder.forClient()
+                    .keyManager(config.cert.toFile(), config.privateKey.toFile())
+                    .trustManager(config.trustedCert.toFile())
+                    .sslProvider(SslProvider.OPENSSL)
+                    .clientAuth(ClientAuth.REQUIRE)
+                    .build()
+
+    private fun NettyOutbound.logConnectionClosed(): NettyOutbound {
+        context().onClose {
+            logger.info { "Connection to ${context().address()} has been closed" }
+        }
+        return this
+    }
+
+    companion object {
+        private val logger = Logger(VesHvClient::class)
+        private const val MAX_BATCH_SIZE = 128
+        private const val eotMessageByte = EndOfTransmissionMessage.MARKER_BYTE
+    }
+}
diff --git a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/adapters/XnfApiServer.kt b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/adapters/XnfApiServer.kt
new file mode 100644
index 00000000..54ead6f7
--- /dev/null
+++ b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/adapters/XnfApiServer.kt
@@ -0,0 +1,95 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.simulators.xnf.impl.adapters
+
+import arrow.core.Either
+import arrow.effects.IO
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.OngoingSimulations
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.Status
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.XnfSimulator
+import org.onap.dcae.collectors.veshv.utils.http.Content
+import org.onap.dcae.collectors.veshv.utils.http.ContentType
+import org.onap.dcae.collectors.veshv.utils.http.HttpConstants
+import org.onap.dcae.collectors.veshv.utils.http.HttpStatus
+import org.onap.dcae.collectors.veshv.utils.http.Response
+import org.onap.dcae.collectors.veshv.utils.http.Responses
+import org.onap.dcae.collectors.veshv.utils.http.sendAndHandleErrors
+import org.onap.dcae.collectors.veshv.utils.http.sendEitherErrorOrResponse
+import org.onap.dcae.collectors.veshv.utils.logging.Logger
+import org.onap.dcae.collectors.veshv.ves.message.generator.api.ParsingError
+import ratpack.handling.Chain
+import ratpack.handling.Context
+import ratpack.http.TypedData
+import ratpack.server.RatpackServer
+import ratpack.server.ServerConfig
+import java.util.*
+import javax.json.Json
+
+/**
+ * @author Jakub Dudycz <jakub.dudycz@nokia.com>
+ * @since June 2018
+ */
+internal class XnfApiServer(
+        private val xnfSimulator: XnfSimulator,
+        private val ongoingSimulations: OngoingSimulations) {
+
+    fun start(port: Int): IO<RatpackServer> = IO {
+        RatpackServer.start { server ->
+            server.serverConfig(ServerConfig.embedded().port(port))
+                    .handlers(this::configureHandlers)
+        }
+    }
+
+    private fun configureHandlers(chain: Chain) {
+        chain
+                .post("simulator", ::startSimulationHandler)
+                .post("simulator/async", ::startSimulationHandler)
+                .get("simulator/:id", ::simulatorStatusHandler)
+                .get("healthcheck") { ctx ->
+                    logger.info("Checking health")
+                    ctx.response.status(HttpConstants.STATUS_OK).send()
+                }
+    }
+
+    private fun startSimulationHandler(ctx: Context) {
+        logger.info("Starting asynchronous scenario")
+        ctx.request.body.then { body ->
+            val id = startSimulation(body)
+            ctx.response.sendEitherErrorOrResponse(id)
+        }
+    }
+
+    private fun startSimulation(body: TypedData): Either<ParsingError, Response> {
+        return xnfSimulator.startSimulation(body.inputStream)
+                .map(ongoingSimulations::startAsynchronousSimulation)
+                .map(Responses::acceptedResponse)
+    }
+
+    private fun simulatorStatusHandler(ctx: Context) {
+        val id = UUID.fromString(ctx.pathTokens["id"])
+        val status = ongoingSimulations.status(id)
+        val response = Responses.statusResponse(status.toString(), status.message)
+        ctx.response.sendAndHandleErrors(IO.just(response))
+    }
+
+    companion object {
+        private val logger = Logger(XnfApiServer::class)
+    }
+}
diff --git a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/config/ArgXnfSimulatorConfiguration.kt b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/config/ArgXnfSimulatorConfiguration.kt
index 999d0327..56d6212a 100644
--- a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/config/ArgXnfSimulatorConfiguration.kt
+++ b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/config/ArgXnfSimulatorConfiguration.kt
@@ -17,7 +17,7 @@
  * limitations under the License.
  * ============LICENSE_END=========================================================
  */
-package org.onap.dcae.collectors.veshv.simulators.xnf.config
+package org.onap.dcae.collectors.veshv.simulators.xnf.impl.config
 
 import arrow.core.ForOption
 import arrow.core.Option
diff --git a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/config/SimulatorConfiguration.kt b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/config/SimulatorConfiguration.kt
index 708ffd13..9b6ef209 100644
--- a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/config/SimulatorConfiguration.kt
+++ b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/config/SimulatorConfiguration.kt
@@ -17,7 +17,7 @@
  * limitations under the License.
  * ============LICENSE_END=========================================================
  */
-package org.onap.dcae.collectors.veshv.simulators.xnf.config
+package org.onap.dcae.collectors.veshv.simulators.xnf.impl.config
 
 import org.onap.dcae.collectors.veshv.domain.SecurityConfiguration
 
@@ -25,7 +25,7 @@ import org.onap.dcae.collectors.veshv.domain.SecurityConfiguration
  * @author Jakub Dudycz <jakub.dudycz@nokia.com>
  * @since June 2018
  */
-internal data class SimulatorConfiguration(
+data class SimulatorConfiguration(
         val listenPort: Int,
         val vesHost: String,
         val vesPort: Int,
diff --git a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/simulations.kt b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/simulations.kt
new file mode 100644
index 00000000..95bb4897
--- /dev/null
+++ b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/impl/simulations.kt
@@ -0,0 +1,76 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.simulators.xnf.impl
+
+import arrow.effects.IO
+import kotlinx.coroutines.experimental.asCoroutineDispatcher
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.adapters.XnfApiServer
+import org.onap.dcae.collectors.veshv.utils.logging.Logger
+import java.util.*
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.Executor
+import java.util.concurrent.Executors
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since August 2018
+ */
+class OngoingSimulations(executor: Executor = Executors.newCachedThreadPool()) {
+    private val asyncSimulationContext = executor.asCoroutineDispatcher()
+    private val simulations = ConcurrentHashMap<UUID, Status>()
+
+    fun startAsynchronousSimulation(simulationIo: IO<Unit>): UUID {
+        val id = UUID.randomUUID()
+        simulations[id] = StatusOngoing
+
+        simulationIo.continueOn(asyncSimulationContext).unsafeRunAsync { result ->
+            result.fold(
+                    { err ->
+                        logger.warn("Error", err)
+                        simulations[id] = StatusFailure(err)
+                    },
+                    {
+                        logger.info("Finished sending messages")
+                        simulations[id] = StatusSuccess
+                    }
+            )
+        }
+        return id
+    }
+
+    fun status(id: UUID) = simulations.getOrDefault(id, StatusNotFound)
+
+    internal fun clear() {
+        simulations.clear()
+    }
+
+    companion object {
+        private val logger = Logger(XnfApiServer::class)
+    }
+}
+
+sealed class Status(val message: String) {
+    override fun toString() = this::class.simpleName ?: "null"
+}
+
+object StatusNotFound : Status("not found")
+object StatusOngoing : Status("ongoing")
+object StatusSuccess : Status("success")
+data class StatusFailure(val cause: Throwable) : Status("Error ${cause.message}")
diff --git a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/main.kt b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/main.kt
index fa6d626b..c9e900ac 100644
--- a/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/main.kt
+++ b/hv-collector-xnf-simulator/src/main/kotlin/org/onap/dcae/collectors/veshv/simulators/xnf/main.kt
@@ -19,12 +19,14 @@
  */
 package org.onap.dcae.collectors.veshv.simulators.xnf
 
-import org.onap.dcae.collectors.veshv.simulators.xnf.config.ArgXnfSimulatorConfiguration
-import org.onap.dcae.collectors.veshv.simulators.xnf.impl.HttpServer
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.OngoingSimulations
 import org.onap.dcae.collectors.veshv.simulators.xnf.impl.XnfSimulator
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.config.ArgXnfSimulatorConfiguration
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.adapters.XnfApiServer
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.adapters.VesHvClient
 import org.onap.dcae.collectors.veshv.utils.arrow.ExitFailure
 import org.onap.dcae.collectors.veshv.utils.arrow.unsafeRunEitherSync
-import org.onap.dcae.collectors.veshv.utils.arrow.void
+import org.onap.dcae.collectors.veshv.utils.arrow.unit
 import org.onap.dcae.collectors.veshv.utils.commandline.handleWrongArgumentErrorCurried
 import org.onap.dcae.collectors.veshv.utils.logging.Logger
 
@@ -38,11 +40,10 @@ const val PROGRAM_NAME = "java $PACKAGE_NAME.MainKt"
  */
 fun main(args: Array<String>) = ArgXnfSimulatorConfiguration().parse(args)
         .mapLeft(handleWrongArgumentErrorCurried(PROGRAM_NAME))
-        .map {config ->
-            XnfSimulator(config)
-                    .let { HttpServer(it) }
+        .map { config ->
+            XnfApiServer(XnfSimulator(VesHvClient(config)), OngoingSimulations())
                     .start(config.listenPort)
-                    .void()
+                    .unit()
         }
         .unsafeRunEitherSync(
                 { ex ->
diff --git a/hv-collector-xnf-simulator/src/test/kotlin/org/onap/dcae/collectors/veshv/main/OngoingSimulationsTest.kt b/hv-collector-xnf-simulator/src/test/kotlin/org/onap/dcae/collectors/veshv/main/OngoingSimulationsTest.kt
new file mode 100644
index 00000000..70d8ba83
--- /dev/null
+++ b/hv-collector-xnf-simulator/src/test/kotlin/org/onap/dcae/collectors/veshv/main/OngoingSimulationsTest.kt
@@ -0,0 +1,107 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.main
+
+import arrow.effects.IO
+import org.assertj.core.api.Assertions.assertThat
+import org.jetbrains.spek.api.Spek
+import org.jetbrains.spek.api.dsl.describe
+import org.jetbrains.spek.api.dsl.given
+import org.jetbrains.spek.api.dsl.it
+import org.jetbrains.spek.api.dsl.on
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.OngoingSimulations
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.StatusFailure
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.StatusNotFound
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.StatusOngoing
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.StatusSuccess
+import org.onap.dcae.collectors.veshv.tests.utils.waitUntilSucceeds
+import java.time.Duration
+import java.util.*
+import java.util.concurrent.Executors
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since September 2018
+ */
+internal class OngoingSimulationsTest : Spek({
+    val executor = Executors.newSingleThreadExecutor()
+    val cut = OngoingSimulations(executor)
+
+    describe("simulations repository") {
+        given("not existing task task id") {
+            val id = UUID.randomUUID()
+
+            on("status") {
+                val result = cut.status(id)
+
+                it("should have 'not found' status") {
+                    assertThat(result).isEqualTo(StatusNotFound)
+                }
+            }
+        }
+
+        given("never ending task") {
+            val task = IO.async<Unit> { }
+
+            on("startAsynchronousSimulation") {
+                val result = cut.startAsynchronousSimulation(task)
+
+                it("should have ongoing status") {
+                    assertThat(cut.status(result)).isEqualTo(StatusOngoing)
+                }
+            }
+        }
+
+        given("failing task") {
+            val cause = RuntimeException("facepalm")
+            val task = IO.raiseError<Unit>(cause)
+
+            on("startAsynchronousSimulation") {
+                val result = cut.startAsynchronousSimulation(task)
+
+                it("should have failing status") {
+                    waitUntilSucceeds {
+                        assertThat(cut.status(result)).isEqualTo(StatusFailure(cause))
+                    }
+                }
+            }
+        }
+
+        given("successful task") {
+            val task = IO { println("great success!") }
+
+            on("startAsynchronousSimulation") {
+                val result = cut.startAsynchronousSimulation(task)
+
+                it("should have successful status") {
+                    waitUntilSucceeds {
+                        assertThat(cut.status(result)).isEqualTo(StatusSuccess)
+                    }
+                }
+            }
+        }
+
+        afterGroup {
+            executor.shutdown()
+        }
+    }
+
+    afterEachTest { cut.clear() }
+})
diff --git a/hv-collector-xnf-simulator/src/test/kotlin/org/onap/dcae/collectors/veshv/main/XnfSimulatorTest.kt b/hv-collector-xnf-simulator/src/test/kotlin/org/onap/dcae/collectors/veshv/main/XnfSimulatorTest.kt
new file mode 100644
index 00000000..80f39579
--- /dev/null
+++ b/hv-collector-xnf-simulator/src/test/kotlin/org/onap/dcae/collectors/veshv/main/XnfSimulatorTest.kt
@@ -0,0 +1,114 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.main
+
+import arrow.core.Left
+import arrow.core.None
+import arrow.core.Right
+import arrow.effects.IO
+import com.nhaarman.mockito_kotlin.any
+import com.nhaarman.mockito_kotlin.mock
+import com.nhaarman.mockito_kotlin.whenever
+import com.sun.xml.internal.messaging.saaj.util.ByteInputStream
+import org.jetbrains.spek.api.Spek
+import org.jetbrains.spek.api.dsl.describe
+import org.jetbrains.spek.api.dsl.it
+import org.onap.dcae.collectors.veshv.domain.PayloadWireFrameMessage
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.XnfSimulator
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.adapters.VesHvClient
+import org.onap.dcae.collectors.veshv.tests.utils.Assertions.assertThat
+import org.onap.dcae.collectors.veshv.ves.message.generator.api.MessageGenerator
+import org.onap.dcae.collectors.veshv.ves.message.generator.api.MessageParameters
+import org.onap.dcae.collectors.veshv.ves.message.generator.api.MessageParametersParser
+import org.onap.dcae.collectors.veshv.ves.message.generator.api.ParsingError
+import reactor.core.publisher.Flux
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since September 2018
+ */
+internal class XnfSimulatorTest : Spek({
+    lateinit var cut: XnfSimulator
+    lateinit var vesClient: VesHvClient
+    lateinit var messageParametersParser: MessageParametersParser
+    lateinit var messageGenerator: MessageGenerator
+
+    beforeEachTest {
+        vesClient = mock()
+        messageParametersParser = mock()
+        messageGenerator = mock()
+        cut = XnfSimulator(vesClient, messageParametersParser, messageGenerator)
+    }
+
+    describe("startSimulation") {
+        it("should fail when empty input stream") {
+            // given
+            val emptyInputStream = ByteInputStream()
+
+            // when
+            val result = cut.startSimulation(emptyInputStream)
+
+            // then
+            assertThat(result).isLeft()
+        }
+
+        it("should fail when invalid JSON") {
+            // given
+            val invalidJson = "invalid json".byteInputStream()
+
+            // when
+            val result = cut.startSimulation(invalidJson)
+
+            // then
+            assertThat(result).isLeft()
+        }
+
+        it("should fail when JSON syntax is valid but content is invalid") {
+            // given
+            val json = "[1,2,3]".byteInputStream()
+            val cause = ParsingError("epic fail", None)
+            whenever(messageParametersParser.parse(any())).thenReturn(
+                    Left(cause))
+
+            // when
+            val result = cut.startSimulation(json)
+
+            // then
+            assertThat(result).left().isEqualTo(cause)
+        }
+
+        it("should return generated messages") {
+            // given
+            val json = "[true]".byteInputStream()
+            val messageParams = listOf<MessageParameters>()
+            val generatedMessages = Flux.empty<PayloadWireFrameMessage>()
+            val sendingIo = IO {}
+            whenever(messageParametersParser.parse(any())).thenReturn(Right(messageParams))
+            whenever(messageGenerator.createMessageFlux(messageParams)).thenReturn(generatedMessages)
+            whenever(vesClient.sendIo(generatedMessages)).thenReturn(sendingIo)
+
+            // when
+            val result = cut.startSimulation(json)
+
+            // then
+            assertThat(result).right().isSameAs(sendingIo)
+        }
+    }
+})
diff --git a/hv-collector-xnf-simulator/src/test/kotlin/org/onap/dcae/collectors/veshv/main/config/ArgXnfSimulatorConfiurationTest.kt b/hv-collector-xnf-simulator/src/test/kotlin/org/onap/dcae/collectors/veshv/main/config/ArgXnfSimulatorConfiurationTest.kt
index 8749dc5b..69caf727 100644
--- a/hv-collector-xnf-simulator/src/test/kotlin/org/onap/dcae/collectors/veshv/main/config/ArgXnfSimulatorConfiurationTest.kt
+++ b/hv-collector-xnf-simulator/src/test/kotlin/org/onap/dcae/collectors/veshv/main/config/ArgXnfSimulatorConfiurationTest.kt
@@ -26,9 +26,9 @@ import org.jetbrains.spek.api.dsl.given
 import org.jetbrains.spek.api.dsl.it
 import org.jetbrains.spek.api.dsl.on
 import org.onap.dcae.collectors.veshv.domain.SecurityConfiguration
-import org.onap.dcae.collectors.veshv.simulators.xnf.config.ArgXnfSimulatorConfiguration
-import org.onap.dcae.collectors.veshv.simulators.xnf.config.ArgXnfSimulatorConfiguration.DefaultValues
-import org.onap.dcae.collectors.veshv.simulators.xnf.config.SimulatorConfiguration
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.config.ArgXnfSimulatorConfiguration
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.config.ArgXnfSimulatorConfiguration.DefaultValues
+import org.onap.dcae.collectors.veshv.simulators.xnf.impl.config.SimulatorConfiguration
 import org.onap.dcae.collectors.veshv.tests.utils.parseExpectingFailure
 import org.onap.dcae.collectors.veshv.tests.utils.parseExpectingSuccess
 import org.onap.dcae.collectors.veshv.utils.commandline.WrongArgumentError