using Microsoft.Extensions.Logging;
using NLog;
using StackExchange.Redis;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace EgwCoreLib.Lux.Data.Services
{
    public class RedisSubscriptionManager
    {
        #region Public Constructors

        public RedisSubscriptionManager(IConnectionMultiplexer connection)
        {
            _subscriber = connection.GetSubscriber();
        }

        #endregion Public Constructors

        #region Public Methods

        public IEnumerable<string> GetActiveChannels() => _subscriptions.Keys;

        public bool Subscribe(string channel, Action<RedisChannel, RedisValue> handler)
        {
            if (_subscriptions.ContainsKey(channel))
                return false;

            RedisChannel rChannel = new RedisChannel(channel, RedisChannel.PatternMode.Literal);
            var task = _subscriber.SubscribeAsync(rChannel, handler);
            _subscriptions[channel] = new ChannelSubscription(channel, handler);
            Log.Info($"✅ Subscribed to channel: {channel}");

            return true;
        }

        public bool Unsubscribe(string channel)
        {
            if (!_subscriptions.TryRemove(channel, out var sub))
                return false;

            RedisChannel rChannel = new RedisChannel(channel, RedisChannel.PatternMode.Literal);
            _subscriber.Unsubscribe(rChannel, sub.Handler);
            Log.Info($"❌ Unsubscribed from channel: {channel}");

            return true;
        }

        #endregion Public Methods

        #region Private Fields

        private static Logger Log = LogManager.GetCurrentClassLogger();
        private readonly ISubscriber _subscriber;

        private readonly ConcurrentDictionary<string, ChannelSubscription> _subscriptions = new();

        #endregion Private Fields
    }

    public record ChannelSubscription(string Channel, Action<RedisChannel, RedisValue> Handler);
}