/*
 * ============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.tests.component

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.it
import org.onap.dcae.collectors.veshv.tests.fakes.*
import org.onap.dcae.collectors.veshv.tests.utils.endOfTransmissionWireMessage
import org.onap.dcae.collectors.veshv.tests.utils.garbageFrame
import org.onap.dcae.collectors.veshv.tests.utils.wireFrameMessageWithInvalidPayload
import org.onap.dcae.collectors.veshv.tests.utils.invalidWireFrame
import org.onap.ves.VesEventV5.VesEvent.CommonEventHeader.Domain
import org.onap.dcae.collectors.veshv.tests.utils.vesWireFrameMessage
import org.onap.dcae.collectors.veshv.tests.utils.vesMessageWithTooBigPayload
import reactor.core.publisher.Flux
import java.time.Duration

/**
 * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
 * @since May 2018
 */
object VesHvSpecification : Spek({
    debugRx(false)

    describe("VES High Volume Collector") {
        it("should handle multiple HV RAN events") {
            val (sut, sink) = vesHvWithStoringSink()
            val messages = sut.handleConnection(sink,
                    vesWireFrameMessage(Domain.HVRANMEAS),
                    vesWireFrameMessage(Domain.HVRANMEAS)
            )

            assertThat(messages)
                    .describedAs("should send all events")
                    .hasSize(2)
        }

        it("should not handle messages received from client after end-of-transmission message") {
            val (sut, sink) = vesHvWithStoringSink()
            val validMessage = vesWireFrameMessage(Domain.HVRANMEAS)
            val anotherValidMessage = vesWireFrameMessage(Domain.HVRANMEAS)
            val endOfTransmissionMessage = endOfTransmissionWireMessage()

            val handledEvents = sut.handleConnection(sink,
                    validMessage,
                    endOfTransmissionMessage,
                    anotherValidMessage
            )

            assertThat(handledEvents).hasSize(1)
            assertThat(validMessage.refCnt())
                    .describedAs("first message should be released")
                    .isEqualTo(0)
            assertThat(endOfTransmissionMessage.refCnt())
                    .describedAs("end-of-transmission message should be released")
                    .isEqualTo(0)
            assertThat(anotherValidMessage.refCnt())
                    .describedAs("second (not handled) message should not be released")
                    .isEqualTo(1)
        }
    }

    describe("Memory management") {
        it("should release memory for each handled and dropped message") {
            val (sut, sink) = vesHvWithStoringSink()
            val validMessage = vesWireFrameMessage(Domain.HVRANMEAS)
            val msgWithInvalidDomain = vesWireFrameMessage(Domain.OTHER)
            val msgWithInvalidFrame = invalidWireFrame()
            val msgWithTooBigPayload = vesMessageWithTooBigPayload(Domain.HVRANMEAS)
            val expectedRefCnt = 0

            val handledEvents = sut.handleConnection(
                    sink, validMessage, msgWithInvalidDomain, msgWithInvalidFrame, msgWithTooBigPayload)

            assertThat(handledEvents).hasSize(1)

            assertThat(validMessage.refCnt())
                    .describedAs("handled message should be released")
                    .isEqualTo(expectedRefCnt)
            assertThat(msgWithInvalidDomain.refCnt())
                    .describedAs("message with invalid domain should be released")
                    .isEqualTo(expectedRefCnt)
            assertThat(msgWithInvalidFrame.refCnt())
                    .describedAs("message with invalid frame should be released")
                    .isEqualTo(expectedRefCnt)
            assertThat(msgWithTooBigPayload.refCnt())
                    .describedAs("message with payload exceeding 1MiB should be released")
                    .isEqualTo(expectedRefCnt)
        }

        it("should release memory for end-of-transmission message") {
            val (sut, sink) = vesHvWithStoringSink()
            val validMessage = vesWireFrameMessage(Domain.HVRANMEAS)
            val endOfTransmissionMessage = endOfTransmissionWireMessage()
            val expectedRefCnt = 0

            val handledEvents = sut.handleConnection(sink,
                    validMessage,
                    endOfTransmissionMessage
            )

            assertThat(handledEvents).hasSize(1)
            assertThat(validMessage.refCnt())
                    .describedAs("handled message should be released")
                    .isEqualTo(expectedRefCnt)
            assertThat(endOfTransmissionMessage.refCnt())
                    .describedAs("end-of-transmission message should be released")
                    .isEqualTo(expectedRefCnt)
        }

        it("should release memory for each message with invalid payload") {
            val (sut, sink) = vesHvWithStoringSink()
            val validMessage = vesWireFrameMessage(Domain.HVRANMEAS)
            val msgWithInvalidPayload = wireFrameMessageWithInvalidPayload()
            val expectedRefCnt = 0

            val handledEvents = sut.handleConnection(sink, validMessage, msgWithInvalidPayload)

            assertThat(handledEvents).hasSize(1)

            assertThat(validMessage.refCnt())
                    .describedAs("handled message should be released")
                    .isEqualTo(expectedRefCnt)
            assertThat(msgWithInvalidPayload.refCnt())
                    .describedAs("message with invalid payload should be released")
                    .isEqualTo(expectedRefCnt)

        }

        it("should release memory for each message with garbage frame") {
            val (sut, sink) = vesHvWithStoringSink()
            val validMessage = vesWireFrameMessage(Domain.HVRANMEAS)
            val msgWithGarbageFrame = garbageFrame()
            val expectedRefCnt = 0

            val handledEvents = sut.handleConnection(sink, validMessage, msgWithGarbageFrame)

            assertThat(handledEvents).hasSize(1)

            assertThat(validMessage.refCnt())
                    .describedAs("handled message should be released")
                    .isEqualTo(expectedRefCnt)
            assertThat(msgWithGarbageFrame.refCnt())
                    .describedAs("message with garbage frame should be released")
                    .isEqualTo(expectedRefCnt)

        }
    }

    describe("message routing") {
        it("should direct message to a topic by means of routing configuration") {
            val (sut, sink) = vesHvWithStoringSink()

            val messages = sut.handleConnection(sink, vesWireFrameMessage(Domain.HVRANMEAS))
            assertThat(messages).describedAs("number of routed messages").hasSize(1)

            val msg = messages[0]
            assertThat(msg.topic).describedAs("routed message topic").isEqualTo(HVRANMEAS_TOPIC)
            assertThat(msg.partition).describedAs("routed message partition").isEqualTo(0)
        }

        it("should be able to direct 2 messages from different domains to one topic") {
            val (sut, sink) = vesHvWithStoringSink()

            sut.configurationProvider.updateConfiguration(twoDomainsToOneTopicConfiguration)

            val messages = sut.handleConnection(sink,
                    vesWireFrameMessage(Domain.HVRANMEAS),
                    vesWireFrameMessage(Domain.HEARTBEAT),
                    vesWireFrameMessage(Domain.MEASUREMENTS_FOR_VF_SCALING))

            assertThat(messages).describedAs("number of routed messages").hasSize(3)

            assertThat(messages[0].topic).describedAs("first message topic")
                    .isEqualTo(HVRANMEAS_TOPIC)

            assertThat(messages[1].topic).describedAs("second message topic")
                    .isEqualTo(HVRANMEAS_TOPIC)

            assertThat(messages[2].topic).describedAs("last message topic")
                    .isEqualTo(MEASUREMENTS_FOR_VF_SCALING_TOPIC)
        }

        it("should drop message if route was not found") {
            val (sut, sink) = vesHvWithStoringSink()
            val messages = sut.handleConnection(sink,
                    vesWireFrameMessage(Domain.OTHER, "first"),
                    vesWireFrameMessage(Domain.HVRANMEAS, "second"),
                    vesWireFrameMessage(Domain.HEARTBEAT, "third"))

            assertThat(messages).describedAs("number of routed messages").hasSize(1)

            val msg = messages[0]
            assertThat(msg.topic).describedAs("routed message topic").isEqualTo(HVRANMEAS_TOPIC)
            assertThat(msg.message.header.eventId).describedAs("routed message eventId").isEqualTo("second")
        }
    }

    describe("configuration update") {

        val defaultTimeout = Duration.ofSeconds(10)

        it("should update collector on configuration change") {
            val (sut, _) = vesHvWithStoringSink()

            sut.configurationProvider.updateConfiguration(basicConfiguration)
            val firstCollector = sut.collector

            sut.configurationProvider.updateConfiguration(configurationWithDifferentRouting)
            val collectorAfterUpdate = sut.collector

            assertThat(collectorAfterUpdate).isNotSameAs(firstCollector)

        }

        it("should start routing messages on configuration change") {
            val (sut, sink) = vesHvWithStoringSink()

            sut.configurationProvider.updateConfiguration(configurationWithoutRouting)

            val messages = sut.handleConnection(sink, vesWireFrameMessage(Domain.HVRANMEAS))
            assertThat(messages).isEmpty()

            sut.configurationProvider.updateConfiguration(basicConfiguration)

            val messagesAfterUpdate = sut.handleConnection(sink, vesWireFrameMessage(Domain.HVRANMEAS))
            assertThat(messagesAfterUpdate).hasSize(1)
            val message = messagesAfterUpdate[0]

            assertThat(message.topic).describedAs("routed message topic after configuration's change")
                    .isEqualTo(HVRANMEAS_TOPIC)
            assertThat(message.partition).describedAs("routed message partition")
                    .isEqualTo(0)
        }

        it("should change domain routing on configuration change") {
            val (sut, sink) = vesHvWithStoringSink()

            sut.configurationProvider.updateConfiguration(basicConfiguration)

            val messages = sut.handleConnection(sink, vesWireFrameMessage(Domain.HVRANMEAS))
            assertThat(messages).hasSize(1)
            val firstMessage = messages[0]

            assertThat(firstMessage.topic).describedAs("routed message topic on initial configuration")
                    .isEqualTo(HVRANMEAS_TOPIC)
            assertThat(firstMessage.partition).describedAs("routed message partition")
                    .isEqualTo(0)


            sut.configurationProvider.updateConfiguration(configurationWithDifferentRouting)

            val messagesAfterUpdate = sut.handleConnection(sink, vesWireFrameMessage(Domain.HVRANMEAS))
            assertThat(messagesAfterUpdate).hasSize(2)
            val secondMessage = messagesAfterUpdate[1]

            assertThat(secondMessage.topic).describedAs("routed message topic after configuration's change")
                    .isEqualTo(ALTERNATE_HVRANMEAS_TOPIC)
            assertThat(secondMessage.partition).describedAs("routed message partition")
                    .isEqualTo(0)
        }

        it("should update routing for each client sending one message") {
            val (sut, sink) = vesHvWithStoringSink()

            sut.configurationProvider.updateConfiguration(basicConfiguration)

            val messagesAmount = 10
            val messagesForEachTopic = 5

            Flux.range(0, messagesAmount).doOnNext {
                if (it == messagesForEachTopic) {
                    sut.configurationProvider.updateConfiguration(configurationWithDifferentRouting)
                }
            }.doOnNext {
                sut.handleConnection(sink, vesWireFrameMessage(Domain.HVRANMEAS))
            }.then().block(defaultTimeout)


            val messages = sink.sentMessages
            val firstTopicMessagesCount = messages.count { it.topic == HVRANMEAS_TOPIC }
            val secondTopicMessagesCount = messages.count { it.topic == ALTERNATE_HVRANMEAS_TOPIC }

            assertThat(messages.size).isEqualTo(messagesAmount)
            assertThat(messagesForEachTopic)
                    .describedAs("amount of messages routed to each topic")
                    .isEqualTo(firstTopicMessagesCount)
                    .isEqualTo(secondTopicMessagesCount)
        }


        it("should not update routing for client sending continuous stream of messages") {
            val (sut, sink) = vesHvWithStoringSink()

            sut.configurationProvider.updateConfiguration(basicConfiguration)

            val messageStreamSize = 10
            val pivot = 5

            val incomingMessages = Flux.range(0, messageStreamSize)
                    .doOnNext {
                        if (it == pivot) {
                            sut.configurationProvider.updateConfiguration(configurationWithDifferentRouting)
                            println("config changed")
                        }
                    }
                    .map { vesWireFrameMessage(Domain.HVRANMEAS) }


            sut.collector.handleConnection(sut.alloc, incomingMessages).block(defaultTimeout)

            val messages = sink.sentMessages
            val firstTopicMessagesCount = messages.count { it.topic == HVRANMEAS_TOPIC }
            val secondTopicMessagesCount = messages.count { it.topic == ALTERNATE_HVRANMEAS_TOPIC }

            assertThat(messages.size).isEqualTo(messageStreamSize)
            assertThat(firstTopicMessagesCount)
                    .describedAs("amount of messages routed to first topic")
                    .isEqualTo(messageStreamSize)

            assertThat(secondTopicMessagesCount)
                    .describedAs("amount of messages routed to second topic")
                    .isEqualTo(0)
        }
    }

    describe("request validation") {
        it("should reject message with payload greater than 1 MiB and all subsequent messages") {
            val (sut, sink) = vesHvWithStoringSink()

            val handledMessages = sut.handleConnection(sink,
                    vesWireFrameMessage(Domain.HVRANMEAS, "first"),
                    vesMessageWithTooBigPayload(Domain.HVRANMEAS),
                    vesWireFrameMessage(Domain.HVRANMEAS))

            assertThat(handledMessages).hasSize(1)
            assertThat(handledMessages.first().message.header.eventId).isEqualTo("first")
        }
    }

})

private fun vesHvWithStoringSink(): Pair<Sut, StoringSink> {
    val sink = StoringSink()
    val sut = Sut(sink)
    sut.configurationProvider.updateConfiguration(basicConfiguration)
    return Pair(sut, sink)
}