rework and starts for new friends system

Govor.Application/Services/Friends/FriendshipService.cs

@@ -0,0 +1,64 @@
+using Govor.Application.Exceptions.FriendsService;
+using Govor.Application.Interfaces.Friends;
+using Govor.Core.Models;
+using Govor.Core.Repositories.Friendships;
+using Govor.Core.Repositories.Users;
+using Govor.Data.Repositories.Exceptions;
+
+namespace Govor.Application.Services.Friends;
+
+public class FriendshipService : IFriendshipService
+{
+    private readonly IUsersRepository _usersRepository;
+    private readonly IFriendshipsRepository _friendshipsRepository;
+
+    public FriendshipService(IUsersRepository usersRepository, IFriendshipsRepository friendshipsRepository)
+    {
+        _usersRepository = usersRepository;
+        _friendshipsRepository = friendshipsRepository;
+    }
+
+    public async Task<List<User>> SearchUsersAsync(string query, Guid currentId)
+    {
+        List<User> all = new List<User>();
+        
+        try
+        {
+            all = await _usersRepository.SearchPotentialFriendsAsync(currentId, query);
+
+            return all
+                .Where(u => u.Id != currentId)
+                .ToList();
+        }
+        catch (NotFoundByKeyException<(string, Guid)> ex)
+        {
+            throw new SearchUsersException(
+                $"Users with given query: \"{query}\" for user with id {currentId} was not found", ex);
+        }
+        catch (NotFoundByKeyException<Guid> ex)
+        {
+            return all.Where(u => u.Id != currentId).ToList();
+        }
+        catch (Exception ex)
+        {
+            throw new UnauthorizedAccessException($"When we try find friends by pattern {query} something wrong", ex);
+        }
+    }
+
+    public async Task<List<User>> GetFriendsAsync(Guid userId)
+    {
+        try
+        {
+            var friendships = await _friendshipsRepository.FindByUserIdAsync(userId);
+
+            return friendships
+                .Where(f => f.Status == FriendshipStatus.Accepted)
+                .Select(f => f.RequesterId == userId ? f.Addressee : f.Requester)
+                .ToList();
+        }
+        catch (NotFoundByKeyException<Guid> ex)
+        {
+            throw new InvalidOperationException("User not found", ex);
+        }
+    }
+}