Common-VS2019/SacsStandardBase/Base/Email/SaEmailConsole.cs

using MailKit.Net.Smtp;
using MailKit.Security;
using MimeKit;
using Sarand.Net.Standard.Base.App;
using Sarand.Net.Standard.Base.Core;
using Sarand.Net.Standard.Base.Utils;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;

namespace Sarand.Net.Standard.Base.Email
{
	//=======================================================================
	public abstract class SaEmailConsole
	{
		//-------------------------------------------------------------------
		// Protected construction.
		protected SaEmailConsole()
		{
		}

		//-------------------------------------------------------------------
		// Send email.
		//-------------------------------------------------------------------
		public bool SendEmail(SaEmailData emailData)
		{
			// Validate email data.
			if (emailData.AddressesTo.IsEmpty())
			{
				SaLogger.Error($"{SysUtil.Fn} Unable to send email - To address not specified.");
				return false;
			}

			try
			{
				// Mail message.
				MimeMessage mailMessage = CreateMailMessage(emailData);

				// Send the email.
				using (var smtpClient = new SmtpClient())
				{
					smtpClient.ServerCertificateValidationCallback = (s, c, h, e) => true;

					smtpClient.Connect(emailData.Config.SMTP.Server, emailData.Config.SMTP.ServerPort, emailData.Config.SMTP.UseSSL ? SecureSocketOptions.StartTlsWhenAvailable : SecureSocketOptions.Auto);
					if (!StringUtil.IsEmpty(emailData.Config.Send.UserName))
						smtpClient.Authenticate(emailData.Config.Send.UserName, emailData.Config.Send.Password);
					smtpClient.Send(mailMessage);
					smtpClient.Disconnect(true);
				}
			}
			catch (Exception exc)
			{
				SaLogger.Error($"{SysUtil.Fn} {ExceptionUtil.GetLogMessage(exc)}");
				return false;
			}
			SaLogger.Info($"{SysUtil.Fn} Email sent to {emailData.AddressesTo[0]}. Subject: {emailData.Subject}");
			return true;
		}

		//-------------------------------------------------------------------
		private MimeMessage CreateMailMessage(SaEmailData emailData)
		{
			// Mail message.
			MimeMessage mailMessage = new MimeMessage();

			// Addresses.
			mailMessage.From.Add(new MailboxAddress("", emailData.Config.Message.AddressFrom));
			foreach (String addressTo in emailData.AddressesTo)
				mailMessage.To.Add(new MailboxAddress("", addressTo));
			foreach (String addressCc in emailData.AddressesCc)
				mailMessage.Cc.Add(new MailboxAddress("", addressCc));
			foreach (String addressBcc in emailData.AddressesBcc)
				mailMessage.Bcc.Add(new MailboxAddress("", addressBcc));
			foreach (String addressBcc in emailData.Config.Message.AddressesBcc)
				mailMessage.Bcc.Add(new MailboxAddress("", addressBcc));

			// Body builder.
			var builder = new BodyBuilder();

			// First add the message itself.
			mailMessage.Subject = emailData.Subject;
			if (emailData.HtmlBody)
				builder.HtmlBody = emailData.MessageBody;
			else
				builder.TextBody = emailData.MessageBody;

			// Attachments.
			int attachmentCount = 0;
			foreach (SaEmailAttachmentData attachmentData in emailData.Attachments)
			{
				attachmentCount++;

				// Construct attachment.
				MimePart attachment = new MimePart(attachmentData.ContentType.MediaType, attachmentData.ContentType.MediaSubtype)
				{
					Content = new MimeContent(new MemoryStream(attachmentData.Data)),
					ContentDisposition = new ContentDisposition(attachmentData.Inline ? ContentDisposition.Inline : ContentDisposition.Attachment),
					ContentTransferEncoding = ContentEncoding.Base64
				};

				// All attachments should have a Filename.
				attachment.FileName = attachmentData.Filename;
				if (StringUtil.IsEmpty(attachment.FileName))
					attachment.FileName = "Attachment_" + StringUtil.PadLeft(attachmentCount.ToString(), 3, '0') + ".dat";

				// Inline attachments also have a ContentId.
				if (attachmentData.Inline)
				{
					attachment.ContentId = attachmentData.ContentId;
					if (StringUtil.IsEmpty(attachmentData.ContentId))
						attachmentData.ContentId = "Attachment_" + StringUtil.PadLeft(attachmentCount.ToString(), 3, '0') + "@saxonite.com";

					// Add the inline attachment as a linked resource.
					builder.LinkedResources.Add(attachment);
				}
				else
				{
					// Add the attachment.
					builder.Attachments.Add(attachment);
				}
			}

			// Populate the message body.
			mailMessage.Body = builder.ToMessageBody();

			return mailMessage;
		}

		//-------------------------------------------------------------------
		// Replace dynamic Email Body tags.
		//-------------------------------------------------------------------
		// Tags.
		/// <summary>Check whether the body includes a specific tag.</summary>
		public static bool EmailContainsTag(SaEmailData emailData, String tag)
		{
			return (Regex.Matches(emailData.MessageBody, Regex.Escape(tag), RegexOptions.IgnoreCase).Count > 0);
		}
		/// <summary>Replace a dynamic tag in the email message.</summary>
		public static void ReplaceDynamicEmailTag(SaEmailData emailData, String tag, String content)
		{
			if (EmailContainsTag(emailData, tag))
				emailData.MessageBody = Regex.Replace(emailData.MessageBody, Regex.Escape(tag), content ?? "", RegexOptions.IgnoreCase);
		}
		/// <summary>
		/// Replace dynamic tags in email message that are known to the base project eg.:
		/// <para>- stylesheet (including style tags).</para>
		/// </summary>
		public static void ReplaceDynamicEmailTags(SaEmailData emailData)
		{
			// Nothing to do.
		}

		//-------------------------------------------------------------------
		protected void AddInlineImageToEmail(SaEmailData emailData, String imageResourceName, byte[] imageData, String imageType = "png")
		{
			string tag = "[#image." + imageResourceName + "]";
			String imageFilename = Regex.Replace(imageResourceName, "_" + imageType, "." + imageType);
			if (Regex.Matches(emailData.MessageBody, Regex.Escape(tag), RegexOptions.IgnoreCase).Count > 0)
			{
				String imageContentId = FormatAttachmentContentId(Regex.Replace(imageFilename, "\\.", "_"));
				if (!emailData.Attachments.Exists(item => StringUtil.EmptyOnNull(item.ContentId).EqualsCI(imageContentId)))
				{
					// Image not yet in attachments.
					SaEmailAttachmentData attachment = new SaEmailAttachmentData("image", imageResourceName)
					{
						Filename = imageFilename,
						ContentId = imageContentId,
						Data = imageData,
						Inline = true
					};
					emailData.Attachments.Add(attachment);
				}
				String content = "cid:" + imageContentId;
				emailData.MessageBody = Regex.Replace(emailData.MessageBody, Regex.Escape(tag), content, RegexOptions.IgnoreCase);
			}
		}

		//-------------------------------------------------------------------
		public static String FormatAttachmentContentId(String attachmentName)
		{
			// Inline content Ids should be formatted similar to an email address (user@domain).
			// Replace '@' and whitespace with underscores and add domain.
			String contentId = Regex.Replace(Regex.Replace(Regex.Replace(attachmentName, "@", "_"), "\\s+", "_"), "_+", "_") + "@saxonite.com";
			return contentId;
		}

		//-------------------------------------------------------------------
	}
	//=======================================================================
}