namespace ZhiYi.Core.Application.RedisServices
{
    /// <summary>
    /// Redis订阅/发布
    /// </summary>
    public class SubscribeAndPublishService
    {

        private readonly IConnectionMultiplexer _redisConnectionMultiplexer;
        private readonly ConcurrentDictionary<string, (ISubscriber subscriber, RedisChannel redisChannel)> _subscriptions = new();
        private readonly ILogger<SubscribeAndPublishService> _logger;

        public SubscribeAndPublishService(IConnectionMultiplexer connectionMultiplexer, ILogger<SubscribeAndPublishService> logger)
        {
            _redisConnectionMultiplexer = connectionMultiplexer;
            _logger = logger;
        }

        /// <summary>
        /// 订阅
        /// </summary>
        /// <param name="clientId"></param>
        public void Subscribe(string clientId, IWebSocket socket)
        {
            try
            {
                var subscriber = _redisConnectionMultiplexer.GetSubscriber();
                var channel = "notifications:" + clientId;//频道可拓展为动态
                _logger.LogInformation("开始订阅 'notifications' 频道, clientID为 {clientId}", clientId);
                var handler = new Action<RedisChannel, RedisValue>(async (ch, value) =>
                {
                    var notification = JsonConvert.DeserializeObject<Notification>(Encoding.UTF8.GetString(value));
                    if (notification != null && notification.ClientId == clientId)
                    {
                        _logger.LogInformation("订阅到 'notifications' 频道, clientID为 {clientId}", clientId);
                        //await _hubContext.Clients.Client(clientId).SendAsync("ReceiveNotification", notification.Message);
                        await socket.SendAsync(notification.Message);
                    }
                });
                subscriber.Subscribe(channel, handler);
                _subscriptions[clientId] = (subscriber, channel);
            }
            catch (Exception ex)
            {
                _logger.LogError("订阅出错, {message}", ex.Message);
            }
        }

        /// <summary>
        /// 发布
        /// </summary>
        /// <param name="message"></param>
        /// <param name="clientId"></param>
        public void Publish(string message, string clientId)
        {
            try
            {
                var notification = new Notification { Message = message, ClientId = clientId };
                var serializedMessage = JsonConvert.SerializeObject(notification);
                var bytes = Encoding.UTF8.GetBytes(serializedMessage);
                var publisher = _redisConnectionMultiplexer.GetSubscriber();
                publisher.Publish(channel: "notifications:" + clientId, message: bytes);
            }
            catch (Exception ex)
            {
                _logger.LogError("发布出错, {message}", ex.Message);
            }
        }



        /// <summary>
        /// 取消订阅
        /// </summary>
        /// <param name="clientId"></param>
        public void Unsubscribe(string clientId)
        {
            if (_subscriptions.TryGetValue(clientId, out var value))
            {
                value.subscriber.Unsubscribe(value.redisChannel + ":" + clientId);
                _ = _subscriptions.TryRemove(clientId, out var sub);
            }
        }

    }

    /// <summary>
    /// 消息管道内容
    /// </summary>
    public class Notification
    {
        /// <summary>
        /// 消息
        /// </summary>
        public string Message { get; set; }

        /// <summary>
        /// 客户端ID
        /// </summary>
        public string ClientId { get; set; }

        /// <summary>
        /// 连接信息
        /// </summary>
        public IWebSocket webSocket { get; set; }
    }
}