Refactor friend request services and add SignalR error handling

Split IFriendRequestService into command and query interfaces, refactor related services and tests, and update dependency injection. Add HubResult response model and a SignalR HubExceptionFilter for consistent error handling. Move and update FriendsHub to use new command service and result pattern. Update username validation to allow digits after Cyrillic letters. Add new controllers and configuration for SignalR. Remove obsolete IFriendRequestService and related code.

Govor.API/Hubs/FriendsHub.cs

@@ -1,38 +1,113 @@
+using Govor.Application.Exceptions.FriendsService;
 using Govor.Application.Interfaces.Friends;
 using Govor.Application.Interfaces.Infrastructure.Extensions;
+using Govor.Contracts.Responses.SignalR;
 using Microsoft.AspNetCore.SignalR;
 
 namespace Govor.API.Hubs;
 
 public class FriendsHub : Hub
 {
-    private readonly IFriendRequestService _friendRequestService;
+    private readonly ILogger<FriendsHub> _logger;
+    private readonly IFriendRequestCommandService _friendRequestService;
     private readonly ICurrentUserService _currentUserService;
 
-    public FriendsHub(IFriendRequestService friendRequestService, ICurrentUserService currentUserService)
+    public FriendsHub(IFriendRequestCommandService friendRequestService, ICurrentUserService currentUserService, ILogger<FriendsHub> logger)
     {
         _friendRequestService = friendRequestService;
         _currentUserService = currentUserService;
+        _logger = logger;
     }
 
-    public async Task SendRequest(Guid targetUserId)
+     public async Task<HubResult<object>> SendRequest(Guid targetUserId)
     {
-        var userId = _currentUserService.GetCurrentUserId();
-        await _friendRequestService.SendFriendRequestAsync(userId, targetUserId);
-        await Clients.User(targetUserId.ToString()).SendAsync("FriendRequestReceived", userId);
+        try
+        {
+            var userId = _currentUserService.GetCurrentUserId();
+            await _friendRequestService.SendAsync(userId, targetUserId);
+            await Clients.User(targetUserId.ToString())
+                .SendAsync("FriendRequestReceived", userId);
+
+            _logger.LogInformation($"Friend request received for user {targetUserId} from {userId}.");
+            return HubResult<object>.Created();
+        }
+        catch (InvalidOperationException ex)
+        {
+            _logger.LogWarning(ex, ex.Message);
+            return HubResult<object>.BadRequest(ex.Message);
+        }
+        catch (RequestAlreadySentException ex)
+        {
+            _logger.LogWarning(ex, ex.Message);
+            return HubResult<object>.Conflict(ex.Message);
+        }
+        catch (UnauthorizedAccessException ex)
+        {
+            _logger.LogWarning(ex, ex.Message);
+            return HubResult<object>.Unauthorized(ex.Message);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, ex.Message);
+            return HubResult<object>.Error("Unexpected error! Please try later!");
+        }
     }
 
-    public async Task AcceptRequest(Guid friendshipId)
+    public async Task<HubResult<object>> AcceptRequest(Guid friendshipId)
     {
-        var userId = _currentUserService.GetCurrentUserId();
-        await _friendRequestService.AcceptFriendRequestAsync(friendshipId, userId);
-        await Clients.User(userId.ToString()).SendAsync("FriendRequestAccepted", friendshipId);
+        try
+        {
+            var userId = _currentUserService.GetCurrentUserId();
+            await _friendRequestService.AcceptAsync(friendshipId, userId);
+            await Clients.User(userId.ToString())
+                         .SendAsync("FriendRequestAccepted", friendshipId);
+            
+            _logger.LogInformation($"Friend request accepted for user {userId} from {userId}.");
+            return HubResult<object>.Ok();
+        }
+        catch (InvalidOperationException ex)
+        {
+            _logger.LogWarning(ex, ex.Message);
+            return HubResult<object>.BadRequest(ex.Message);
+        }
+        catch (UnauthorizedAccessException ex)
+        {
+            _logger.LogWarning(ex, ex.Message);
+            return HubResult<object>.Unauthorized(ex.Message);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, ex.Message);
+            return HubResult<object>.Error("Unexpected error! Please try later!");
+        }
     }
 
-    public async Task RejectRequest(Guid friendshipId)
+    public async Task<HubResult<object>> RejectRequest(Guid friendshipId)
     {
-        var userId = _currentUserService.GetCurrentUserId();
-        await _friendRequestService.RejectFriendRequestAsync(friendshipId, userId);
-        await Clients.User(userId.ToString()).SendAsync("FriendRequestRejected", friendshipId);
+        try
+        {
+            var userId = _currentUserService.GetCurrentUserId();
+            await _friendRequestService.RejectAsync(friendshipId, userId);
+            await Clients.User(userId.ToString())
+                         .SendAsync("FriendRequestRejected", friendshipId);
+            
+            _logger.LogInformation($"Friend request rejected for user {userId} from {userId}.");
+            return HubResult<object>.Ok();
+        }
+        catch (InvalidOperationException ex)
+        {
+            _logger.LogWarning(ex, ex.Message);
+            return HubResult<object>.BadRequest(ex.Message);
+        }
+        catch (UnauthorizedAccessException ex)
+        {
+            _logger.LogWarning(ex, ex.Message);
+            return HubResult<object>.Unauthorized(ex.Message);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, ex.Message);
+            return HubResult<object>.Error("Unexpected error! Please try later!");
+        }
     }
 }