/*
 * ============LICENSE_START=======================================================
 * dcaegen2-collectors-veshv
 * ================================================================================
 * Copyright (C) 2018-2019 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.fakes

import org.onap.dcae.collectors.veshv.boundary.Sink
import org.onap.dcae.collectors.veshv.model.ConsumedMessage
import org.onap.dcae.collectors.veshv.model.FailedToConsumeMessage
import org.onap.dcae.collectors.veshv.model.MessageDropCause
import org.onap.dcae.collectors.veshv.domain.RoutedMessage
import org.onap.dcae.collectors.veshv.model.SuccessfullyConsumedMessage
import org.reactivestreams.Publisher
import reactor.core.publisher.Flux
import reactor.core.publisher.Mono
import java.time.Duration
import java.util.*
import java.util.concurrent.ConcurrentLinkedDeque
import java.util.concurrent.atomic.AtomicBoolean
import java.util.concurrent.atomic.AtomicLong

/**
 * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
 * @since May 2018
 */
class StoringSink : Sink {
    private val sent: Deque<RoutedMessage> = ConcurrentLinkedDeque()
    private val active = AtomicBoolean(true)
    val closed get() = !active.get()

    val sentMessages: List<RoutedMessage>
        get() = sent.toList()

    override fun send(messages: Flux<RoutedMessage>): Flux<ConsumedMessage> {
        return messages.doOnNext(sent::addLast).map(::SuccessfullyConsumedMessage)
    }

    override fun close(): Mono<Void> = Mono.fromRunnable {
        active.set(false)
    }
}

/**
 * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
 * @since May 2018
 */
class CountingSink : Sink {
    private val atomicCount = AtomicLong(0)

    val count: Long
        get() = atomicCount.get()

    override fun send(messages: Flux<RoutedMessage>): Flux<ConsumedMessage> {
        return messages.doOnNext {
            atomicCount.incrementAndGet()
        }.map(::SuccessfullyConsumedMessage)
    }
}


open class ProcessingSink(private val transformer: (Flux<RoutedMessage>) -> Publisher<ConsumedMessage>) : Sink {
    override fun send(messages: Flux<RoutedMessage>): Flux<ConsumedMessage> =
            messages.transform(transformer)
}

class AlwaysSuccessfulSink : ProcessingSink({ it.map(::SuccessfullyConsumedMessage) })

class AlwaysFailingSink : ProcessingSink({ stream ->
    stream.map { FailedToConsumeMessage(it, null, MessageDropCause.KAFKA_FAILURE) }
})

class DelayingSink(delay: Duration) : ProcessingSink({ it.delayElements(delay).map(::SuccessfullyConsumedMessage) })