hermes-client/Twitch/Socket/TwitchConnectionManager.cs

using CommonSocketLibrary.Abstract;
using Microsoft.Extensions.DependencyInjection;
using Serilog;
using TwitchChatTTS.Twitch.Socket.Messages;

namespace TwitchChatTTS.Twitch.Socket
{
    public interface ITwitchConnectionManager
    {
        TwitchWebsocketClient GetWorkingClient();
        TwitchWebsocketClient GetBackupClient();
    }

    public class TwitchConnectionManager : ITwitchConnectionManager
    {
        private TwitchWebsocketClient? _identified;
        private TwitchWebsocketClient? _backup;
        private readonly IServiceProvider _serviceProvider;
        private readonly ILogger _logger;

        private readonly object _lock;

        public TwitchConnectionManager(IServiceProvider serviceProvider, ILogger logger)
        {
            _serviceProvider = serviceProvider;
            _logger = logger;

            _lock = new object();
        }


        public TwitchWebsocketClient GetBackupClient()
        {
            lock (_lock)
            {
                if (_identified == null)
                    throw new InvalidOperationException("Cannot get backup Twitch client yet. Waiting for identification.");
                if (_backup != null)
                    return _backup;

                return CreateNewClient();
            }
        }

        public TwitchWebsocketClient GetWorkingClient()
        {
            lock (_lock)
            {
                if (_identified == null)
                {
                    return CreateNewClient();
                }

                return _identified;
            }
        }

        private TwitchWebsocketClient CreateNewClient()
        {
            if (_backup != null)
                return _backup;

            var client = (_serviceProvider.GetRequiredKeyedService<SocketClient<TwitchWebsocketMessage>>("twitch-create") as TwitchWebsocketClient)!;
            client.Initialize();
            _backup = client;

            client.OnIdentified += async (_, _) => await OnIdentified(client);
            client.OnDisconnected += async (_, _) => await OnDisconnection(client);

            _logger.Debug("Created a Twitch websocket client.");
            return client;
        }

        private async Task OnDisconnection(TwitchWebsocketClient client)
        {
            bool reconnecting = false;
            lock (_lock)
            {
                if (_identified?.UID == client.UID)
                {
                    _logger.Debug($"Identified Twitch client has disconnected [client: {client.UID}][main: {_identified.UID}][backup: {_backup?.UID}]");
                    _identified = null;
                    reconnecting = true;
                }
                else if (_backup?.UID == client.UID)
                {
                    _logger.Debug($"Backup Twitch client has disconnected [client: {client.UID}][main: {_identified?.UID}][backup: {_backup.UID}]");
                    _backup = null;
                }
                else if (client.ReceivedReconnecting)
                    _logger.Debug($"Twitch client disconnected due to reconnection [client: {client.UID}][main: {_identified?.UID}][backup: {_backup?.UID}]");
                else
                    _logger.Warning($"Twitch client disconnected from unknown source [client: {client.UID}][main: {_identified?.UID}][backup: {_backup?.UID}]");
            }

            if (reconnecting)
            {
                var newClient = GetWorkingClient();
                await newClient.Reconnect();
            }
        }

        private async Task OnIdentified(TwitchWebsocketClient client)
        {
            bool clientDisconnect = false;
            lock (_lock)
            {
                if (_identified == null || _identified.ReceivedReconnecting)
                {
                    if (_backup != null && _backup.UID == client.UID)
                    {
                        _logger.Debug($"Twitch client has been identified [client: {client.UID}][main: {_identified?.UID}][backup: {_backup.UID}]");
                        _identified = _backup;
                        _backup = null;
                    }
                    else
                        _logger.Warning($"Twitch client identified from unknown sources [client: {client.UID}][main: {_identified?.UID}][backup: {_backup?.UID}]");
                }
                else if (_identified.UID == client.UID)
                {
                    _logger.Debug($"Twitch client has been re-identified [client: {client.UID}][main: {_identified.UID}][backup: {_backup?.UID}]");
                }
                else if (_backup == null || _backup.UID != client.UID)
                {
                    _logger.Warning($"Twitch client has been identified, but isn't main or backup [client: {client.UID}][main: {_identified.UID}][backup: {_backup?.UID}]");
                    clientDisconnect = true;
                }
            }

            if (clientDisconnect)
                await client.DisconnectAsync(new SocketDisconnectionEventArgs("Closed", "No need for a tertiary client."));
        }
    }
}