using StackExchange.Redis;
using System;

namespace SteamWare
{
    /// <summary>
    /// Classe gestione PubSub messaggi REDIS
    /// </summary>
    public class MessagePipe
    {
        #region Private Fields

        private bool enableLog = false;
        private IConnectionMultiplexer redis;
        private IDatabase redisDb;

        #endregion Private Fields

        #region Protected Fields

        /// <summary>
        /// Obj x gestione log
        /// </summary>
        protected static NLog.Logger Log = NLog.LogManager.GetCurrentClassLogger();

        #endregion Protected Fields

        #region Public Constructors

        /// <summary>
        /// Init canale di comunicazione PubSub via REDIS
        /// </summary>
        /// <param name="channelName"></param>
        /// <param name="enableLog"></param>
        public MessagePipe(string channelName, bool enableLog = false)
        {
            _channel = channelName;
            redis = memLayer.ML.connRedis;
            redisDb = redis.GetDatabase();
            this.enableLog = enableLog;
            // aggiungo sottoscrittore
            setupSubscriber();
        }

        #endregion Public Constructors

        #region Public Events

        /// <summary>
        /// Messaggio veicolato dal canale
        /// </summary>
        public event EventHandler EA_NewMessage = delegate { };

        #endregion Public Events

        #region Private Properties

        /// <summary>
        /// Canale associato al gestore pipeline messaggi
        /// </summary>
        private string _channel { get; set; } = "";

        #endregion Private Properties

        #region Private Methods

        private void setupSubscriber()
        {
            ISubscriber sub = redis.GetSubscriber();
            //Subscribe to the channel named messages
            sub.Subscribe(_channel, (channel, message) =>
            {
                Log.Trace($"ch {channel} | {message}");
                // messaggio
                PubSubEventArgs mea = new PubSubEventArgs(message);
                // se qualcuno ascolta sollevo evento nuovo valore...
                if (EA_NewMessage != null)
                {
                    EA_NewMessage(this, mea);
                }
            });
            Log.Info($"Subscribed {_channel}");
        }

        #endregion Private Methods

        #region Public Methods

        /// <summary>
        /// Invio messaggio sul canale + salvataggio in cache REDIS
        /// </summary>
        /// <param name="memKey">Chiave REDIS x salvare valore</param>
        /// <param name="message"></param>
        public bool saveAndSendMessage(string memKey, string message)
        {
            bool answ = false;
            // invio notifica tramite il canale richiesto
            answ = sendMessage(message);
            if (redisDb != null)
            {
                redisDb.StringSetAsync(memKey, message);
                if (enableLog)
                {
                    Log.Info($"Redis Cache Key: {memKey}");
                }
            }
            return answ;
        }

        /// <summary>
        /// Invio messaggio sul canale
        /// </summary>
        /// <param name="newMess"></param>
        /// <returns></returns>
        public bool sendMessage(string newMess)
        {
            bool answ = false;
            ISubscriber sub = redis.GetSubscriber();
            sub.Publish(_channel, newMess);
            return answ;
        }

        #endregion Public Methods
    }

    /// <summary>
    /// Evento messaggio PubSub Redis
    /// </summary>
    public class PubSubEventArgs : EventArgs
    {
        #region Public Constructors

        /// <summary>
        /// Costruttore
        /// </summary>
        /// <param name="messaggio"></param>
        public PubSubEventArgs(string messaggio)
        {
            this.newMessage = messaggio;
        }

        #endregion Public Constructors

        #region Public Properties

        /// <summary>
        /// Messaggio trasportato
        /// </summary>
        public string newMessage { get; set; } = "";

        #endregion Public Properties
    }
}