using System;
using System.ComponentModel.DataAnnotations;

using System.Net.Mail;
using System.Reactive.Subjects;
using Serilog;


namespace Rko.Eip.Dsa.Dap.Pipeline.NotificationService
{
    public class NotificationService : INotificationService
    {
        private readonly SmtpClientConfig _clientConfig;
        private readonly ILogger _logger;
        private readonly Subject<Notification> _mailSentNotification =  new Subject<Notification>();

        public NotificationService(SmtpClientConfig config, ILogger logger )
        {
            _clientConfig = config;
            _logger = logger;
            _mailSentNotification.Subscribe(n => DoJob(n));
        }

        public void EnqueueNotification(Notification notification, NotificationOptions  options)
        {

            var emailChecker = new EmailAddressAttribute();
            //TODO: сделать валидацию и рассылку об ошибках  типа как в IValidatable в эко
            foreach (var target in notification.Targets)
            {
                if (emailChecker.IsValid(target) == false)
                    throw new ArgumentException($"Target {target} is not a valid e-mail");
            }

            if (emailChecker.IsValid(_clientConfig.Email) == false)
                throw new ArgumentException($"Sender {_clientConfig.Email} is not a valid e-mail");

            try
            {
                _mailSentNotification.OnNext(notification);

            }
            catch (Exception e)
            {
                _logger.Error(e.Message);
                throw e;
            }
        }

        private void DoJob(Notification notification)
        {
            using (var smtp = new SmtpClient(_clientConfig.Host)
            {
                EnableSsl = _clientConfig.EnableSsl,
                Port = _clientConfig.Port,
                Credentials = _clientConfig.Credentials
            })
            {
                var message = new MailMessage();
                foreach (var target in notification.Targets)
                {
                    message.To.Add(target);
                }

                message.From = new MailAddress(_clientConfig.Email, _clientConfig.Email);
                message.Subject = notification.Header;
                message.Body = notification.Text;

                smtp.Send(message);
            }
        }
    }
}