using LiteNetLib;
using Serilog;

namespace ClientTester.EchoDummyService;

public class EchoDummyClientService
{
    private readonly List<EchoDummyClients> clients;
    private readonly int sendInterval;

    // 유닛 테스트용 (n패킷 시간체크)
    public bool IsTest
    {
        get;
        set;
    } = false;

    public int TestCount
    {
        get;
        set;
    } = 100000;

    // 모든거 강종
    public event Action? OnAllDisconnected;

    public EchoDummyClientService(int count, string ip, int port, string key, int sendIntervalMs = 1000)
    {
        sendInterval = sendIntervalMs;
        clients = Enumerable.Range(0, count).Select(i => new EchoDummyClients(i, ip, port, key)).ToList();

        Log.Information("[SERVICE] {Count}개 클라이언트 생성 → {Ip}:{Port}", count, ip, port);
    }

    public async Task RunAsync(CancellationToken ct)
    {
        if (IsTest)
        {
            foreach (EchoDummyClients c in clients)
            {
                c.TestCount = TestCount;
            }

            Log.Information("[TEST] 유닛 테스트 모드: 클라이언트당 {Count}개 수신 시 자동 종료", TestCount);
        }

        await Task.WhenAll(
            PollLoopAsync(ct),
            SendLoopAsync(ct)
        );
    }

    private async Task PollLoopAsync(CancellationToken ct)
    {
        while (!ct.IsCancellationRequested)
        {
            foreach (EchoDummyClients c in clients)
            {
                c.PollEvents();
            }

            try
            {
                await Task.Delay(10, ct);
            }
            catch (OperationCanceledException)
            {
                break;
            }
        }
    }

    private async Task SendLoopAsync(CancellationToken ct)
    {
        try
        {
            await Task.Delay(500, ct);
        }
        catch (OperationCanceledException)
        {
            return;
        }

        int tick = 0;

        while (!ct.IsCancellationRequested)
        {
            int sent = 0;
            int total = clients.Count;

            foreach (EchoDummyClients client in clients)
            {
                client.SendPing();
                if (client.peer != null)
                {
                    sent++;
                }
                else
                {
                    total--;
                }
            }

            if (total == 0)
            {
                Log.Information("All Disconnect Clients");
                OnAllDisconnected?.Invoke();
                break;
            }

            Log.Debug("[TICK {Tick:000}] {Sent}/{Total} 전송", tick, sent, total);
            tick++;

            try
            {
                await Task.Delay(sendInterval, ct);
            }
            catch (OperationCanceledException)
            {
                break;
            }
        }
    }

    public void PrintStats()
    {
        int totalSent = 0, totalRecv = 0;
        int connected = 0;
        int rttClientCount = 0;

        Log.Information("───────────── Performance Report ─────────────");

        double totalAvgRtt = 0;

        foreach (EchoDummyClients c in clients)
        {
            NetStatistics? stats = c.peer?.Statistics;
            long loss = stats?.PacketLoss ?? 0;
            float lossPct = stats?.PacketLossPercent ?? 0f;

            Log.Information(
                "[Client {ClientId:00}] Sent={Sent} Recv={Recv} | Loss={Loss}({LossPct:F1}%) AvgRTT={AvgRtt:F3}ms LastRTT={LastRtt:F3}ms",
                c.clientId, c.SentCount, c.ReceivedCount, loss, lossPct, c.AvgRttMs, c.LastRttMs);

            totalSent += c.SentCount;
            totalRecv += c.ReceivedCount;
            if (c.RttCount > 0)
            {
                totalAvgRtt += c.AvgRttMs;
                rttClientCount++;
            }

            if (c.peer != null)
            {
                connected++;
            }
        }

        double avgRtt = rttClientCount > 0 ? totalAvgRtt / rttClientCount : 0;

        Log.Information("────────────────────────────────────────────");
        Log.Information(
            "[TOTAL] Sent={Sent} Recv={Recv} Connected={Connected}/{Total} AvgRTT={AvgRtt:F3}ms",
            totalSent, totalRecv, connected, clients.Count, avgRtt);
        Log.Information("────────────────────────────────────────────");
    }

    public void Stop()
    {
        foreach (EchoDummyClients c in clients)
        {
            c.Stop();
        }

        Log.Information("[SERVICE] 모든 클라이언트 종료됨.");
    }
}