Add user avatar URL

src/Managing.Application/Users/UserService.cs

@@ -1,4 +1,5 @@
-using Managing.Application.Abstractions.Repositories;
+using System.Text.RegularExpressions;
+using Managing.Application.Abstractions.Repositories;
 using Managing.Application.Abstractions.Services;
 using Managing.Common;
 using Managing.Domain.Accounts;
@@ -134,10 +135,33 @@ public class UserService : IUserService
         var existingUser = await _userRepository.GetUserByAgentNameAsync(agentName);
         if (existingUser != null)
         {
-            throw new Exception("Agent name already used");
+            throw new Exception($"Agent name already used by {existingUser.Name}");
+        }
+        else
+        {
+            user.AgentName = agentName;
+            await _userRepository.UpdateUser(user);
+            return user;
+        }
+    }
+
+    public async Task<User> UpdateAvatarUrl(User user, string avatarUrl)
+    {
+        // Validate URL format and image extension
+        if (!Uri.TryCreate(avatarUrl, UriKind.Absolute, out Uri? uriResult) || 
+            (uriResult.Scheme != Uri.UriSchemeHttp && uriResult.Scheme != Uri.UriSchemeHttps))
+        {
+            throw new Exception("Invalid URL format");
         }
 
-        user.AgentName = agentName;
+        // Check for valid image extension
+        string pattern = @"\.(jpeg|jpg|png)$";
+        if (!Regex.IsMatch(avatarUrl, pattern, RegexOptions.IgnoreCase))
+        {
+            throw new Exception("URL must point to a JPEG or PNG image");
+        }
+
+        user.AvatarUrl = avatarUrl;
         await _userRepository.UpdateUser(user);
         return user;
     }