feat(marketing-initiated-premium): (Auth) [PM-27541] Add optional marketing param to email verification link (#6604)

Adds an optional `&fromMarketing=premium` query parameter to the verification email link.

Feature flag: `"pm-26140-marketing-initiated-premium-flow"`

src/Core/Auth/Models/Mail/RegisterVerifyEmail.cs

@@ -15,11 +15,13 @@ public class RegisterVerifyEmail : BaseMailModel
     // so we must land on a redirect connector which will redirect to the finish signup page.
     // Note 3: The use of a fragment to indicate the redirect url is to prevent the query string from being logged by
     // proxies and servers. It also helps reduce open redirect vulnerabilities.
-    public string Url => string.Format("{0}/redirect-connector.html#finish-signup?token={1}&email={2}&fromEmail=true",
+    public string Url => string.Format("{0}/redirect-connector.html#finish-signup?token={1}&email={2}&fromEmail=true{3}",
         WebVaultUrl,
         Token,
-        Email);
+        Email,
+        !string.IsNullOrEmpty(FromMarketing) ? $"&fromMarketing={FromMarketing}" : string.Empty);
 
     public string Token { get; set; }
     public string Email { get; set; }
+    public string FromMarketing { get; set; }
 }

src/Core/Auth/UserFeatures/Registration/ISendVerificationEmailForRegistrationCommand.cs

@@ -3,5 +3,5 @@ namespace Bit.Core.Auth.UserFeatures.Registration;
 
 public interface ISendVerificationEmailForRegistrationCommand
 {
-    public Task<string?> Run(string email, string? name, bool receiveMarketingEmails);
+    public Task<string?> Run(string email, string? name, bool receiveMarketingEmails, string? fromMarketing);
 }

src/Core/Auth/UserFeatures/Registration/Implementations/SendVerificationEmailForRegistrationCommand.cs

@@ -44,7 +44,7 @@ public class SendVerificationEmailForRegistrationCommand : ISendVerificationEmai
 
     }
 
-    public async Task<string?> Run(string email, string? name, bool receiveMarketingEmails)
+    public async Task<string?> Run(string email, string? name, bool receiveMarketingEmails, string? fromMarketing)
     {
         if (_globalSettings.DisableUserRegistration)
         {
@@ -92,7 +92,7 @@ public class SendVerificationEmailForRegistrationCommand : ISendVerificationEmai
             // If the user doesn't exist, create a new EmailVerificationTokenable and send the user
             // an email with a link to verify their email address
             var token = GenerateToken(email, name, receiveMarketingEmails);
-            await _mailService.SendRegistrationVerificationEmailAsync(email, token);
+            await _mailService.SendRegistrationVerificationEmailAsync(email, token, fromMarketing);
         }
 
         // User exists but we will return a 200 regardless of whether the email was sent or not; so return null

src/Core/Platform/Mail/HandlebarsMailService.cs

@@ -78,7 +78,7 @@ public class HandlebarsMailService : IMailService
         await _mailDeliveryService.SendEmailAsync(message);
     }
 
-    public async Task SendRegistrationVerificationEmailAsync(string email, string token)
+    public async Task SendRegistrationVerificationEmailAsync(string email, string token, string? fromMarketing)
     {
         var message = CreateDefaultMessage("Verify Your Email", email);
         var model = new RegisterVerifyEmail
@@ -86,7 +86,8 @@ public class HandlebarsMailService : IMailService
             Token = WebUtility.UrlEncode(token),
             Email = WebUtility.UrlEncode(email),
             WebVaultUrl = _globalSettings.BaseServiceUri.Vault,
-            SiteName = _globalSettings.SiteName
+            SiteName = _globalSettings.SiteName,
+            FromMarketing = WebUtility.UrlEncode(fromMarketing),
         };
         await AddMessageContentAsync(message, "Auth.RegistrationVerifyEmail", model);
         message.MetaData.Add("SendGridBypassListManagement", true);

src/Core/Platform/Mail/IMailService.cs

@@ -38,7 +38,7 @@ public interface IMailService
     /// <returns>Task</returns>
     Task SendFreeOrgOrFamilyOrgUserWelcomeEmailAsync(User user, string familyOrganizationName);
     Task SendVerifyEmailEmailAsync(string email, Guid userId, string token);
-    Task SendRegistrationVerificationEmailAsync(string email, string token);
+    Task SendRegistrationVerificationEmailAsync(string email, string token, string? fromMarketing);
     Task SendTrialInitiationSignupEmailAsync(
         bool isExistingUser,
         string email,

src/Core/Platform/Mail/NoopMailService.cs

@@ -26,7 +26,7 @@ public class NoopMailService : IMailService
         return Task.FromResult(0);
     }
 
-    public Task SendRegistrationVerificationEmailAsync(string email, string hint)
+    public Task SendRegistrationVerificationEmailAsync(string email, string hint, string? fromMarketing)
     {
         return Task.FromResult(0);
     }

src/Identity/Controllers/AccountsController.cs

@@ -109,8 +109,12 @@ public class AccountsController : Controller
     [HttpPost("register/send-verification-email")]
     public async Task<IActionResult> PostRegisterSendVerificationEmail([FromBody] RegisterSendVerificationEmailRequestModel model)
     {
+        // Only pass fromMarketing if the feature flag is enabled
+        var isMarketingFeatureEnabled = _featureService.IsEnabled(FeatureFlagKeys.MarketingInitiatedPremiumFlow);
+        var fromMarketing = isMarketingFeatureEnabled ? model.FromMarketing : null;
+
         var token = await _sendVerificationEmailForRegistrationCommand.Run(model.Email, model.Name,
-            model.ReceiveMarketingEmails);
+            model.ReceiveMarketingEmails, fromMarketing);
 
         if (token != null)
         {