validations

src/Correo.Application/CommandHandlers/SendEmailHandler.cs

@@ -1,4 +1,5 @@
 using AutoMapper;
+using Correo.Application.Extensions;
 using Correo.Domain.Models;
 using Correo.PublishedLanguage.Commands;
 using Correo.PublishedLanguage.Events;
@@ -35,6 +36,8 @@ namespace Correo.Application.CommandHandlers
                 if (emailMessage.From == null)
                     emailMessage.From = new EmailMessage.MailAddress(_defaultSender.Value.Address, _defaultSender.Value.Name);
 
+                emailMessage.Validate();
+
                 // send email
             }
             catch (Exception ex)

src/Correo.Application/Extensions/ValidationExtensions.cs

@@ -0,0 +1,37 @@
+using Correo.Application.Utils;
+using Correo.Domain.Models;
+using System;
+using System.Linq;
+
+namespace Correo.Application.Extensions
+{
+    internal static class ValidationExtensions
+    {
+        public static void Validate(this EmailMessage emailMessage)
+        {
+            if (string.IsNullOrEmpty(emailMessage.Subject))
+                throw new Exception("Subject is missing.");
+
+            if (string.IsNullOrEmpty(emailMessage.Body))
+                throw new Exception("Body is missing.");
+
+            if (string.IsNullOrEmpty(emailMessage.From.Address))
+                throw new Exception("'From' address is missing.");
+
+            if (!Validations.IsEmail(emailMessage.From.Address))
+                throw new Exception($"'From' email address '{emailMessage.From.Address}' is not valid.");
+
+            if (emailMessage.To.Count() == 0)
+                throw new Exception("'To' addresses are empty.");
+
+            if (emailMessage.To.Any(z => !Validations.IsEmail(z.Address)))
+                throw new Exception("There are invalid email addresses in 'To' list.");
+
+            if (emailMessage.Cc.Any(z => !Validations.IsEmail(z.Address)))
+                throw new Exception("There are invalid email addresses in 'Cc' list.");
+
+            if (emailMessage.Bcc.Any(z => !Validations.IsEmail(z.Address)))
+                throw new Exception("There are invalid email addresses in 'Bcc' list.");
+        }
+    }
+}

src/Correo.Application/Utils/Validations.cs

@@ -0,0 +1,15 @@
+using System.Text.RegularExpressions;
+
+namespace Correo.Application.Utils
+{
+    internal static class Validations
+    {
+        public static bool IsEmail(string email)
+        {
+            var pattern = @"^[\w!#$%&'*+\-/=?\^_`{|}~]+(\.[\w!#$%&'*+\-/=?\^_`{|}~]+)*" + "@" + @"((([\-\w]+\.)+[a-zA-Z]{2,4})|(([0-9]{1,3}\.){3}[0-9]{1,3}))$";
+            var reg = new Regex(pattern);
+            var valid = reg.IsMatch(email);
+            return valid;
+        }
+    }
+}