using System;
using Confluent.Kafka;
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 XKafkaProducerService : XBaseEventProducerService, IXKafkaProducerService
    {
        private readonly IProducer<Null, string> producer;

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

            //
            // Prepare Kafka Producer Configuration ...
            var config = new ProducerConfig
            {
                Acks = Acks.All,
                BootstrapServers = configuration.Url,
                MessageSendMaxRetries = configuration.MaxRetries,
            };
            producer = new ProducerBuilder<Null, string>(config).Build();
        }

        /// <summary>
        /// Sending Message ...
        /// </summary>
        /// <param name="request">an Instance of <see cref="XEventRequest"/> to Provides Kafka Messaging requirement ...</param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<bool> SendMessageAsync(
            XEventRequest request,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Validate ...
            var result = request.IsValid();
            if (!result)
            {
                XException.InvalidArgs.Throw();
            }

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

            //
            return result;
        }

        /// <summary>
        /// Sending a Message ...
        /// </summary>
        /// <param name="message">an Instance of <see cref="XEventMessage"/> to Provides Kafka Messaging requirement ...</param>
        /// <param name="topic">Topic for Sending Message ...</param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task<bool> SendMessageAsync(
            XEventMessage message,
            string topic = XEventServiceConstants.XDefaultTopic,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Validate ...
            var result = message.IsValid() &&
                !topic.IsNullOrEmpty();
            if (!result)
            {
                XException.InvalidArgs.Throw();
            }

            //
            try
            {
                //
                var response = await producer.ProduceAsync(
                    topic: topic,
                    message: new Message<Null, string>
                    {
                        Value = message
                            .ToJSON(camelCase: true)
                    },
                    cancellationToken: cancellationToken
                );

                //
                result = !response.IsNullOrDefault();
            }
            catch (Exception ex)
            {
                //
                logger.LogError($"Kafka Produce Error: {ex.Message} ...");
                result = false;
            }

            //
            return result;
        }

        /// <summary>
        /// Dispose Required Objects ...
        /// </summary>
        public void Dispose()
        {
            //
            if (producer != null)
            {
                producer.Dispose();
            }

            //
            GC.SuppressFinalize(this);
        }
    }
}