using System.Net;
using System.Net.Security;
using System.Net.WebSockets;
using System.Security.Cryptography.X509Certificates;
using Microsoft.AspNetCore.Server.Kestrel.Https;
using PCC2.AssemblyInject.Interfaces;
using PCC2.Backend.Events;
using PCC2.EventBus;
using PCC2.Networking.KestrelSsl;

namespace PCC2.Backend;

internal class Pcc2Listener(IAsyncEventBus eventBus, ILogger<Pcc2Listener> logger, ILogger<KestrelSslListener> kwsLogger) : IAssemblyInjectASyncInitStarStop
{
    private X509Certificate2? ServerCerSelect(string? sni)
    {

        throw new NotImplementedException();
    }

    private bool ClientCerValidate(X509Certificate2 clientCert, X509Chain? arg2, SslPolicyErrors arg3)
    {
        throw new NotImplementedException();
    }

    private Task ConnectHandler(X509Certificate2? clientCert, WebSocket ws)
    {
        throw new NotImplementedException();
    }

    // ==============================================================

    private KestrelSslListener? _listener;

    private ListenerStatus _status;
    private async Task SetAndPublishListenStatus(ListenerStatus status)
    {
        _status = status;
        await eventBus.PublishAsync(new ListenerStatusTellEvent(status));
    }

    public Task InitAsync()
    {
        eventBus.Subscript<ListenSettingChangedEvent>(async delegate
        {
            await StopAsync();
            await StartAsync();
        });

        eventBus.Subscript<ListenerStatusAskEvent>(async delegate
        {
            await eventBus.PublishAsync(new ListenerStatusTellEvent(_status));
        });

        return Task.CompletedTask;
    }

    public async Task StartAsync()
    {
        if (_listener != null) return;
        var ep = LoadListenEndPointSetting();

        if (ep == null)
        {
            await SetAndPublishListenStatus(ListenerStatus.NotStart);
            return;
        }

        await SetAndPublishListenStatus(ListenerStatus.Starting);
        _listener = new KestrelSslListener(ep, ServerCerSelect, ClientCerValidate, ConnectHandler, ClientCertificateMode.RequireCertificate, kwsLogger);
        try
        {
            await _listener.StartAsync();
            await SetAndPublishListenStatus(ListenerStatus.Started);
        }
        catch (Exception ex)
        {
            logger.LogError(ex, nameof(StartAsync));
            await SetAndPublishListenStatus(ListenerStatus.StartFail);
        }
    }

    public async Task StopAsync()
    {
        if (_listener == null) return;

        await SetAndPublishListenStatus(ListenerStatus.Stopping);
        try
        {
            await _listener.StopAsync();
            await SetAndPublishListenStatus(ListenerStatus.Stopped);
        }
        catch (Exception ex)
        {
            logger.LogError(ex, nameof(StopAsync));
            await SetAndPublishListenStatus(ListenerStatus.StopFail);
        }
        _listener = null;
    }
    private IPEndPoint? LoadListenEndPointSetting()
    {
        var settings = GetSettings();
        var ip = settings.ListenAddress;
        var port = settings.ListenPort;
        if (ip == null || port == null || IPAddress.TryParse(ip, out var address) == false) return null;
        return new IPEndPoint(address, port.Value);
    }
}