using Microsoft.Extensions.Logging;
using PARR.EsppTemplateSync.Services;
using PARR.EsppTemplateSync.Settings;
using RabbitMQ.Client;
using RabbitMQ.Client.Events;
using System.Text;

namespace PARR.EsppTemplateSync
{
    internal class TemplateMQSyncer : ITemplateSyncer
    {
        private readonly ILogger<TemplateMQSyncer> logger;
        private readonly IManager manager;
        private readonly GlobalSettings globalSettings;

        private IConnection? connection;
        private IModel? channel;

        public TemplateMQSyncer(
            ILogger<TemplateMQSyncer> logger,
            IManager manager,
            GlobalSettings globalSettings
            )
        {
            this.logger = logger;
            this.manager = manager;
            this.globalSettings = globalSettings;

            if (globalSettings.MqSettings == null)
            {
                logger.LogError("Нет секции настроек хранилища. MqSettings, EsppTemplates");
                throw new Exception("Нет секции настроек хранилища. MqSettings, EsppTemplates");
            }
        }

        public void Start()
        {
            InitConnection();

            logger.LogInformation($"Запущена проверка очереди {globalSettings.MqSettings!.QueueName}.");

            GetMessages();//TODO переименовать в какой-нибудь AttachListener
        }

        public void Stop()
        {
            channel?.Close();
            connection?.Close();

            logger.LogInformation($"=== === === Соединение с очередью {globalSettings.MqSettings!.QueueName} закрыто === === ===");
        }

        private void InitConnection()
        {
            logger.LogInformation($"Устанавливаю соединение с RabbitMQ: {globalSettings.MqSettings!.HostName}");

            var factory = new ConnectionFactory { HostName = globalSettings.MqSettings!.HostName };
            factory.UserName = globalSettings.MqSettings.UserName;
            factory.Password = globalSettings.MqSettings.Password;
            factory.AutomaticRecoveryEnabled = true;
            factory.DispatchConsumersAsync = true;

            connection = factory.CreateConnection();
            channel = connection.CreateModel();

            var args = new Dictionary<string, object>
            {
                { "x-queue-mode", "lazy" }
            };

            channel.QueueDeclare(queue: globalSettings.MqSettings.QueueName,
                               durable: true,
                               exclusive: false,
                               autoDelete: false,
                               arguments: args);

            logger.LogInformation("Соединение с RabbitMQ установлено.");
        }

        private void GetMessages()
        {
            if (channel == null || connection == null)
            {
                logger.LogError("Отсутствует соедниение с RabbitMQ.");
                return;
            }

            var consumer = new AsyncEventingBasicConsumer(channel);

            consumer.Received += async (ch, ea) =>
            {
                var content = Encoding.UTF8.GetString(ea.Body.ToArray());
                logger.LogDebug($"Получено сообщение: {content}");

                await manager.ManageStringAsync(content);

                channel.BasicAck(ea.DeliveryTag, false);
                await Task.Yield();
            };

            channel.BasicConsume(globalSettings.MqSettings!.QueueName, false, consumer);
        }
    }
}