Add CC and BCC to emails

BTCPayServer/Plugins/Emails/Views/StoreEmailRuleViewModel.cs

@@ -2,7 +2,9 @@ using System;
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
+using System.Net.Mail;
 using BTCPayServer.Data;
+using Newtonsoft.Json.Linq;
 
 namespace BTCPayServer.Plugins.Emails.Views;
 
@@ -25,6 +27,8 @@ public class StoreEmailRuleViewModel
             Condition = data.Condition ?? "";
             Body = data.Body;
             To = string.Join(",", data.To);
+            CC = string.Join(",", data.CC);
+            BCC = string.Join(",", data.BCC);
         }
         else
         {
@@ -46,6 +50,8 @@ public class StoreEmailRuleViewModel
     public EmailRuleData Data { get; set; }
     public EmailRuleData.BTCPayAdditionalData AdditionalData { get; set; }
     public string To { get; set; }
+    public string CC { get; set; }
+    public string BCC { get; set; }
 
     public List<EmailTriggerViewModel> Triggers { get; set; }
     public string RedirectUrl { get; set; }
@@ -54,8 +60,29 @@ public class StoreEmailRuleViewModel
     public string OfferingId { get; set; }
     public string StoreId { get; set; }
 
-    public string[] ToAsArray()
-    => (To ?? "").Split(',', StringSplitOptions.RemoveEmptyEntries)
-            .Select(t => t.Trim())
-            .ToArray();
+    public string[] AsArray(string values)
+    {
+        // This replace the placeholders with random email addresses
+        // We can't just split input by comma, because display names of people can contain commas.
+        // "John, Jr. Smith" <jon@example.com>,{User.Email},"Nicolas D." <nico@example.com>
+        values ??= "";
+
+        // We replace the placeholders with dummy email addresses
+        var template = new TextTemplate(values);
+        var dummy = $"{Random.Shared.Next()}@example.com";
+        template.NotFoundReplacement = o => $"\"{o}\" <{dummy}>";
+        values = template.Render(new JObject());
+        if (string.IsNullOrWhiteSpace(values))
+            return Array.Empty<string>();
+        // We use MailAddressCollection to parse the addresses
+        MailAddressCollection mailCollection = new();
+        mailCollection.Add(values);
+        foreach (var mail in  mailCollection)
+        {
+            // Let it throw if the address is invalid
+            MailboxAddressValidator.Parse(mail.ToString());
+        }
+        // We replace the dummies with the former placeholders
+        return mailCollection.Select(a => a.Address == dummy ? $"{{{a.DisplayName}}}" : a.ToString()).ToArray();
+    }
 }