Refactor welcome message handling to UserService for Telegram channel updates

- Moved the welcome message logic from UserController to UserService to centralize user notification handling.
- Improved error logging for message sending failures, ensuring better traceability of issues.
- Enhanced user experience by maintaining the detailed setup information and friendly greeting in the welcome message.

src/Managing.Application/Users/UserService.cs

@@ -20,6 +20,7 @@ public class UserService : IUserService
     private readonly ICacheService _cacheService;
     private readonly IGrainFactory? _grainFactory;
     private readonly IWhitelistService _whitelistService;
+    private readonly IWebhookService _webhookService;
     private readonly string[] _authorizedAddresses;
 
     public UserService(
@@ -30,6 +31,7 @@ public class UserService : IUserService
         ICacheService cacheService,
         IGrainFactory? grainFactory,
         IWhitelistService whitelistService,
+        IWebhookService webhookService,
         IConfiguration configuration)
     {
         _evmManager = evmManager;
@@ -39,6 +41,7 @@ public class UserService : IUserService
         _cacheService = cacheService;
         _grainFactory = grainFactory;
         _whitelistService = whitelistService;
+        _webhookService = webhookService;
 
         var authorizedAddressesString = configuration["AUTHORIZED_ADDRESSES"] ?? string.Empty;
         _authorizedAddresses = string.IsNullOrEmpty(authorizedAddressesString)
@@ -302,6 +305,36 @@ public class UserService : IUserService
         // Update the telegram channel on the provided user object
         user.TelegramChannel = telegramChannel;
         await _userRepository.SaveOrUpdateUserAsync(user);
+
+        // Send welcome message to the newly configured telegram channel
+        if (!string.IsNullOrEmpty(telegramChannel))
+        {
+            try
+            {
+                var welcomeMessage = $"🎉 **Welcome to Kaigen Notifications!**\n\n" +
+                                     $"Hello {user.AgentName}! 👋\n\n" +
+                                     $"Your Telegram channel has been successfully configured and you're now connected to the Kaigen notification system.\n\n" +
+                                     $"📋 **Your Setup Details:**\n" +
+                                     $"• 🎯 **Agent Name:** {user.AgentName}\n" +
+                                     $"• 📡 **Channel ID:** {telegramChannel}\n" +
+                                     $"• ⏰ **Connected:** {DateTime.UtcNow:MMM dd, yyyy • HH:mm:ss} UTC\n\n" +
+                                     $"🔔 **What You'll Receive:**\n" +
+                                     $"• 📈 Real-time position opens and closes\n" +
+                                     $"• 💰 Trading activity updates\n" +
+                                     $"• 🤖 Strategy and configuration changes\n" +
+                                     $"• ⚠️ Important system alerts\n\n" +
+                                     $"✨ **You're all set!** Start receiving your trading notifications right away. If you have any questions, feel free to reach out.\n\n" +
+                                     $"Happy trading! 🚀";
+
+                await _webhookService.SendMessage(welcomeMessage, telegramChannel);
+            }
+            catch (Exception ex)
+            {
+                // Log the error but don't fail the update operation
+                _logger.LogWarning(ex, "Failed to send welcome message to telegram channel {TelegramChannel}", telegramChannel);
+            }
+        }
+
         return user;
     }