lm-sistemi-software-distribuiti/src/main/kotlin/util/network/epidemic/EpidemicNode.kt

package util.network.epidemic

import util.network.epidemic.packet.EpidemicPacket
import util.network.simulator.Address
import util.network.simulator.Network
import util.network.simulator.Node

abstract class EpidemicNode<T, P : EpidemicPacket<T>>(
    address: Address,
    network: Network,
    initialValue: T,
    bufferSize: Int = 1
) : Node(address, network, bufferSize) {
    @Volatile
    var nodeValue = initialValue
        private set
    protected var nodeState = State.SUSCEPTIBLE

    @Synchronized
    fun changeValue(value: T) {
        nodeValue = value
    }

    private fun sendToRandom(
        type: EpidemicPacket.Type,
        numberOfReceiver: Int = 1
    ) {
        val toExclude = mutableListOf(address)
        repeat(numberOfReceiver) {
            var receiverAddress = network.getRandomAddress()
            while (toExclude.contains(receiverAddress))
                receiverAddress = network.getRandomAddress()
            toExclude.add(receiverAddress)

            send(makeInfectionPacket(receiverAddress, type))
        }
    }

    abstract fun makeInfectionPacket(
        receiverAddress: Address,
        type: EpidemicPacket.Type
    ): EpidemicPacket<T>

    protected fun sendPushToRandom(numberOfReceiver: Int = 1) {
        sendToRandom(
            EpidemicPacket.Type.PUSH,
            numberOfReceiver
        )
    }

    protected fun sendPullToRandom(numberOfReceiver: Int = 1) {
        sendToRandom(
            EpidemicPacket.Type.PULL,
            numberOfReceiver
        )
    }

    protected fun sendPushPullToRandom(numberOfReceiver: Int = 1) {
        sendToRandom(
            EpidemicPacket.Type.PUSHPULL,
            numberOfReceiver
        )
    }

    protected abstract fun receivePushOrReply(packet: P)

    protected abstract fun receivePull(packet: P)

    protected abstract fun infect()

    protected fun onReceive(packet: P) {
        when (packet.type) {
            EpidemicPacket.Type.PUSH -> receivePushOrReply(packet)
            EpidemicPacket.Type.PULL -> receivePull(packet)
            EpidemicPacket.Type.REPLY -> receivePushOrReply(packet)
            EpidemicPacket.Type.PUSHPULL -> {
                receivePull(packet)
                receivePushOrReply(packet)
            }
        }
    }

    override fun communicatorFactory(threadGroup: ThreadGroup): CommunicatorFactory {
        return EpidemicCommunicatorFactory(threadGroup)
    }

    protected enum class State {
        SUSCEPTIBLE, INFECTED, REMOVED
    }

    enum class InfectStrategy {
        PUSH, PULL, PUSHPULL
    }

    protected inner class EpidemicReceiver(
        threadGroup: ThreadGroup
    ) : Node.Receiver(threadGroup) {
        override fun run() {
            while (!isInterrupted) {
                val packet = receive() as P
                onReceive(packet)
            }
        }
    }

    protected inner class EpidemicSender(
        threadGroup: ThreadGroup
    ) : Node.Sender(threadGroup) {
        override fun run() {
            while (!isInterrupted)
                infect()
        }
    }

    protected inner class EpidemicCommunicatorFactory(
        threadGroup: ThreadGroup
    ) : Node.CommunicatorFactory(threadGroup) {
        override fun createReceiver(): Receiver {
            return EpidemicReceiver(threadGroup)
        }

        override fun createSender(): Sender {
            return EpidemicSender(threadGroup)
        }
    }
}