ThirdPartyAPI/Business/BusinessLogic/NotificationApiService/EmailService.cs

using Common.Models.Confiq;
using Common.Models.Enums;
using Common.Models.Notification;
using Common.Models.RequestResponse;
using Common.Utility;
using log4net;
using Newtonsoft.Json;
using Repository.DAO.ThirdParty;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Mail;
using System.Net.Mime;
using System.Text;
using System.Threading.Tasks;

namespace Business.BusinessLogic.NotificationApiService
{
    public class EmailService
    {

        private readonly ILog _log = LogManager.GetLogger(typeof(EmailService));

        private readonly IThirdPartyRepo _thirdPartyRepo;
        public EmailService()
        {
            _thirdPartyRepo = new ThirdPartyRepo();
        }
        public TPResponse SendEmail(SendNotificationRequest model)
        {
            TPResponse _tPResponse = new TPResponse();

            // _log.Info($"IsBulkNotification {model.IsBulkNotification}");


            List<TPResponse> tPResponses = new List<TPResponse>();

            Task.Run(() =>
            {
                model.Recipients.ForEach(x =>
                {
                    tPResponses.Add(Email(x, model.Template));
                });

            }).ContinueWith(y =>
            {
                _log.Debug($"SendEmail Responses {JsonConvert.SerializeObject(tPResponses)}");

                _tPResponse.Data = tPResponses;

                //tPResponses.Where(x => x.ResponseCode.Equals("0")).ToList().ForEach(z =>
                //{
                //    _thirdPartyRepo.UpdateNotificationStatus(z.Id);
                //});
            });


            _tPResponse.ResponseCode = "0";
            _tPResponse.Msg = "Email sent succesfully. Check log for details.";

            return _tPResponse;
        }

        private TPResponse Email(RecipientViewModel model, NotifyTemplate template = NotifyTemplate.NONE)
        {
            TPResponse _tPResponse = new TPResponse() { ResponseCode = "1", Id = model.Address };

            SmtpClient SmtpServer = new SmtpClient();
            MailMessage mail = new MailMessage();

            _log.Info($"Sending email for {model.Address}");
            try
            {
                if (model.MailAddress != null && !string.IsNullOrEmpty(model.MailAddress.FromEmail))
                {
                    mail.From = new MailAddress(model.MailAddress.FromEmail, model.MailAddress.AliasName ?? string.Empty);
                }

                if (!string.IsNullOrEmpty(model.Address))
                {
                    mail.To.Add(model.Address);
                }

                if (!string.IsNullOrEmpty(model.CcAddress))
                {
                    mail.To.Add(model.CcAddress);
                }
                if (!string.IsNullOrEmpty(model.BccAddress))
                {
                    mail.To.Add(model.BccAddress);
                }


                if (model.NotificationContent.Attachments != null)
                {
                    foreach (var item in model.NotificationContent.Attachments)
                    {
                        Attachment attachment = null;
                        if (!string.IsNullOrEmpty(item.FilePath))
                        {
                            attachment = new Attachment(item.FilePath, item.FileType);
                        }
                        else
                        {
                            var bytes = Convert.FromBase64String(item.Byte64String);
                            MemoryStream strm = new MemoryStream(bytes);
                             attachment = new Attachment(strm, item.FileName);
                        }

                        if (attachment != null)
                        {
                            ContentDisposition disposition = attachment.ContentDisposition;
                            disposition.Inline = true;
                            disposition.FileName = Path.GetFileName(item.FileName);                            
                            disposition.DispositionType = DispositionTypeNames.Attachment;
                            mail.Attachments.Add(attachment);
                        }
                    }
                }

                if (model.NotificationContent.EmbeddedResources != null)
                {
                    if (model.NotificationContent.EmbeddedResources.Any())
                    {
                        AlternateView vw = GetEmbeddedImage(model.NotificationContent.EmbeddedResources, model.NotificationContent.Body);
                        mail.AlternateViews.Add(vw);
                    }
                }

                mail.Subject = model.NotificationContent.Title;
                mail.IsBodyHtml = true;

                if (template != NotifyTemplate.NONE)
                {
                    var templatePath = Helpers.GetMapping(Common.Models.Enums.MappingType.EMAIL_TEMPLATE, template.ToString());

                    string fullPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, templatePath.DValue);
                    mail.Subject = templatePath.DText;

                    string body = string.Empty;
                    using (StreamReader reader = new StreamReader(fullPath))
                    {
                        body = reader.ReadToEnd();
                    }

                    if (!string.IsNullOrEmpty(model.NotificationContent.Body) && !model.NotificationContent.Body.StartsWith("<img"))
                    {
                        List<Mapping> mappings = JsonConvert.DeserializeObject<List<Mapping>>(model.NotificationContent.Body);

                        mappings.ForEach(x =>
                        {
                            body = body.Replace(string.Format("{{{0}}}", x.SValue), x.SText);
                        });
                    }
                    mail.Body = body;

                }
                else
                    mail.Body = model.NotificationContent.Body;


                // SmtpServer.Timeout = 25000;
                SmtpServer.Send(mail);
                mail.Dispose();
                SmtpServer.Dispose();
                _tPResponse.ResponseCode = "0";
                _tPResponse.Id = model.BroadCastNoticeId.ToString();
                _tPResponse.Msg = _tPResponse.ResponseCode.Equals("0") ? "Email Sent Sucessfully." : "Email Sending Failed.";

                _thirdPartyRepo.UpdateNotificationStatus(model.BroadCastNoticeId.ToString());

                _log.Info($"Sending email for {model.Address} | {JsonConvert.SerializeObject(_tPResponse)}");
            }
            catch (SmtpFailedRecipientsException ex)
            {
                for (int i = 0; i < ex.InnerExceptions.Length; i++)
                {
                    SmtpStatusCode status = ex.InnerExceptions[i].StatusCode;
                    if (status == SmtpStatusCode.MailboxBusy || status == SmtpStatusCode.MailboxUnavailable)
                    {
                        // Console.WriteLine("Delivery failed - retrying in 5 seconds.");
                        System.Threading.Thread.Sleep(5000);
                        SmtpServer.Send(mail);
                    }
                    else
                    {
                        //  Console.WriteLine("Failed to deliver message to {0}", ex.InnerExceptions[i].FailedRecipient);
                        //throw ex;
                        _tPResponse.Msg = ex.Message;
                        _log.Error($"Error Sending email for {model.Address}", ex);
                    }
                }
                _tPResponse.ResponseCode = "1";
            }
            catch (Exception ex)
            {
                _tPResponse.ResponseCode = "1";
                _tPResponse.Msg = ex.Message;
                _log.Error($"Error Sending email for {model.Address}", ex);
            }
            finally
            {
              
               // SmtpServer.Dispose();
            }

            return _tPResponse;
        }

        private AlternateView GetEmbeddedImage(List<AttachmentModel> attachmentList, string htmlBody)
        {
            AlternateView alternateView = AlternateView.CreateAlternateViewFromString(htmlBody, null, MediaTypeNames.Text.Html);
            foreach (var item in attachmentList)
            {
                byte[] bytes = System.Convert.FromBase64String(item.Byte64String);
                LinkedResource res = new LinkedResource(new MemoryStream(bytes), item.FileType);
                res.ContentId = item.FileName;
                alternateView.LinkedResources.Add(res);
            }
            return alternateView;
        }


    }
}