identity: set default mfa method to email for new users

Streetwriters.Identity/Controllers/MFAController.cs

@@ -79,9 +79,12 @@ namespace Streetwriters.Identity.Controllers
         }
 
         [HttpDelete]
-        public IActionResult Disable2FA()
+        public async Task<IActionResult> Disable2FA()
         {
-            return BadRequest("2FA is mandatory and cannot be disabled.");
+            var user = await UserManager.GetUserAsync(User) ?? throw new Exception("User not found.");
+            if (!await UserManager.GetTwoFactorEnabledAsync(user)) return Ok();
+            await MFAService.DisableMFAAsync(user);
+            return Ok();
         }
 
         [HttpGet("codes")]

Streetwriters.Identity/Services/UserAccountService.cs

@@ -34,12 +34,6 @@ namespace Streetwriters.Identity.Services
             var claims = await userManager.GetClaimsAsync(user);
             var marketingConsentClaim = claims.FirstOrDefault((claim) => claim.Type == $"{clientId}:marketing_consent");
 
-            if (await userManager.IsEmailConfirmedAsync(user) && !await userManager.GetTwoFactorEnabledAsync(user))
-            {
-                await mfaService.EnableMFAAsync(user, MFAMethods.Email);
-                user = await userManager.FindByIdAsync(userId);
-                ArgumentNullException.ThrowIfNull(user);
-            }
             ArgumentNullException.ThrowIfNull(user.Email);
 
             return new UserModel
@@ -163,6 +157,7 @@ namespace Streetwriters.Identity.Services
                     }
                     else
                     {
+                        await mfaService.EnableMFAAsync(user, MFAMethods.Email);
                         if (userAgent != null) await userManager.AddClaimAsync(user, new Claim("platform", PlatformFromUserAgent(userAgent)));
                         var code = await userManager.GenerateEmailConfirmationTokenAsync(user);
                         var callbackUrl = UrlExtensions.TokenLink(user.Id.ToString(), code, client.Id, TokenType.CONFRIM_EMAIL);

Streetwriters.Identity/Validation/EmailGrantValidator.cs

@@ -59,7 +59,6 @@ namespace Streetwriters.Identity.Validation
 
         public string GrantType => Config.EMAIL_GRANT_TYPE;
 
-
         public async Task ValidateAsync(ExtensionGrantValidationContext context)
         {
             var email = context.Request.Raw["email"];
@@ -76,8 +75,14 @@ namespace Streetwriters.Identity.Validation
             };
 
             var isMultiFactor = await UserManager.GetTwoFactorEnabledAsync(user);
+            if (!isMultiFactor)
+            {
+                context.Result.IsError = false;
+                context.Result.Subject = await TokenGenerationService.TransformTokenRequestAsync(context.Request, user, GrantType, [Config.MFA_PASSWORD_GRANT_TYPE_SCOPE]);
+                return;
+            }
 
-            var primaryMethod = isMultiFactor ? MFAService.GetPrimaryMethod(user) : MFAMethods.Email;
+            var primaryMethod = MFAService.GetPrimaryMethod(user);
             var secondaryMethod = MFAService.GetSecondaryMethod(user);
             var sendPhoneNumber = primaryMethod == MFAMethods.SMS || secondaryMethod == MFAMethods.SMS;