using NetMQ;
using System;
using System.Text;
using NetMQ.Sockets;
using System.Threading;
using xCommons.Extensions;
using xEventService.Models;
using xExceptions.Constants;
using System.Threading.Tasks;
using xEventService.Constants;
using xEventService.Extensions;
using xEventService.Interfaces;
using xEventService.Configuration;
using Microsoft.Extensions.Logging;

namespace xEventService.Providers
{
    public class XZeroMQProducerService : XBaseEventProducerService, IXZeroMQProducerService
    {
        //
        private NetMQSocket socket;
        private readonly object socketLock = new();

        public XZeroMQProducerService(
            XEventServiceConfiguration configuration,
            ILogger<XZeroMQProducerService> logger
        ) : base(configuration, logger)
        {
            //
            // Validate Configurations ...
            if (!configuration.IsValid() ||
                !configuration.ZeroMQ.IsValid() ||
                configuration.Broker != XEventBroker.XZeroMQ
            )
            {
                XException.InvalidConfiguration.Throw();
            }

            //
            InitializeSocket();
        }

        /// <summary>
        /// Sending Message with Full Request Descriptor ...
        /// </summary>
        /// <param name="request"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<bool> SendMessageAsync(
            XEventRequest request,
            CancellationToken cancellationToken = default
        )
        {
            //
            var result = request.IsValid();
            if (!result)
            {
                XException.InvalidArgs.Throw();
            }

            //
            result = await SendMessageAsync(
                message: request.Message,
                topic: request.Topic,
                cancellationToken: cancellationToken
            );

            //
            return result;
        }

        /// <summary>
        /// Sending a Message to Topic ...
        /// </summary>
        /// <param name="message"></param>
        /// <param name="topic"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<bool> SendMessageAsync(
            XEventMessage message,
            string topic = XEventServiceConstants.XDefaultTopic,
            CancellationToken cancellationToken = default
        )
        {
            //
            var result = message.IsValid();
            if (!result)
            {
                XException.InvalidArgs.Throw();
            }

            //
            // Normalize Topic ...
            if (topic.IsNullOrEmpty())
            {
                topic = XEventServiceConstants.XDefaultTopic;
            }

            //
            try
            {
                //
                var json = message.ToJSON(camelCase: true);
                var body = Encoding.UTF8.GetBytes(json);
                await Task.Run(() =>
                {
                    //
                    lock (socketLock)
                    {
                        //
                        if (configuration.ZeroMQ.Pattern == XZeroMQPattern.PubSub)
                        {
                            socket.SendMoreFrame(topic).SendFrame(body);
                        }
                        else
                        {
                            socket.SendFrame(body);
                        }
                    }
                }, cancellationToken);

                //
                result = true;
            }
            catch (Exception)
            {
                result = false;
            }

            //
            return result;
        }

        /// <summary>
        /// Dispose Object ...
        /// </summary>
        public void Dispose()
        {
            //
            try
            {
                //
                lock (socketLock)
                {
                    //
                    if (socket != null)
                    {
                        //
                        socket.Close();
                        socket.Dispose();
                        socket = null;
                    }
                }
            }
            catch { }

            //
            GC.SuppressFinalize(this);
        }

        //
        #region Private ...
        /// <summary>
        /// Initialize Socket ...
        /// </summary>
        private void InitializeSocket()
        {
            //
            lock (socketLock)
            {
                //
                if (configuration.ZeroMQ.Pattern == XZeroMQPattern.PubSub)
                {
                    //
                    socket = new PublisherSocket();
                    socket.Options.SendHighWatermark = configuration.ZeroMQ.SendHighWaterMark;
                }
                else
                {
                    //
                    socket = new PushSocket();
                    socket.Options.SendHighWatermark = configuration.ZeroMQ.SendHighWaterMark;
                }

                //
                if (configuration.ZeroMQ.IsServer)
                {
                    socket.Bind(configuration.Url);
                }
                else
                {
                    socket.Connect(configuration.Url);
                }
            }
        }
        #endregion
    }
}