/*
 * Copyright 2023 dorkbox, llc
 *
 * 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.
 */

package dorkboxTest.network

import dorkbox.network.Client
import dorkbox.network.Configuration
import dorkbox.network.Server
import dorkbox.network.connection.Connection
import dorkbox.util.NamedThreadFactory
import kotlinx.atomicfu.atomic
import kotlinx.coroutines.DelicateCoroutinesApi
import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.asCoroutineDispatcher
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking
import org.junit.Assert
import org.junit.Test
import java.text.SimpleDateFormat
import java.util.*
import java.util.concurrent.*

@Suppress("UNUSED_ANONYMOUS_PARAMETER")
class MultiClientTest : BaseTest() {
    private val totalCount = 40

    private val clientConnectCount = atomic(0)
    private val serverConnectCount = atomic(0)
    private val disconnectCount = atomic(0)

    @OptIn(DelicateCoroutinesApi::class, ExperimentalCoroutinesApi::class)
    @Test
    fun multiConnectClient() {
        run {
            val configuration = serverConfig()
            configuration.enableIPv6 = false
            configuration.uniqueAeronDirectory = true

            val server: Server<Connection> = Server(configuration)
            addEndPoint(server)
            server.onConnect {
                val count = serverConnectCount.incrementAndGet()

                logger.error("${this.id} - Connected $count ....")
                close()
            }

            server.bind()
        }


        println()
        println()
        println()
        println()

        val shutdownLatch = CountDownLatch(totalCount)


        // clients first, so they try to connect to the server at (roughly) the same time
        val clients = mutableListOf<Client<Connection>>()
        for (i in 1..totalCount) {
            val config = clientConfig()
            config.enableIPv6 = false
            config.uniqueAeronDirectory = true

            val client: Client<Connection> = Client(config, "Client $i")
            client.onInit {
                val count = clientConnectCount.incrementAndGet()
                logger.error("$id - Connected $count ($i)!")
            }

            client.onDisconnect {
                val count = disconnectCount.incrementAndGet()
                logger.error("$id - Disconnected $count ($i)!")
                shutdownLatch.countDown()
            }

            addEndPoint(client)
            clients += client
        }

        // start up the drivers first
        runBlocking {
            clients.forEach {
                it.startDriver()
            }
        }

        // if we are on the same JVM, the defaultScope for coroutines is SHARED, and limited!
        val differentThreadLaunchers = Executors.newFixedThreadPool(8,
            NamedThreadFactory("Unit Test Client", Configuration.networkThreadGroup, true)
        ).asCoroutineDispatcher()

        runBlocking {
            clients.forEach {
                launch(differentThreadLaunchers) {
                    it.connect(LOCALHOST, 30)
                }
            }
        }

        shutdownLatch.await()
        stopEndPointsBlocking()

        Assert.assertEquals(totalCount, clientConnectCount.value)
        Assert.assertEquals(totalCount, serverConnectCount.value)
        Assert.assertEquals(totalCount, disconnectCount.value)
    }

    fun outputStats(server: Server<Connection>) {
        val dateFormat = SimpleDateFormat("HH:mm:ss")
        print(dateFormat.format(Date()))
        println("======================================================================")
        server.driverCounters { counterId, counterValue, typeId, keyBuffer, label ->
            //if (counterFilter.filter(typeId, keyBuffer)) {
            System.out.format("%3d: %,20d - %s%n", counterId, counterValue, label)
            //}
        }

        println(server.driverBacklog()?.output())
    }
}