chat: add initial GuildsController

Foxchat.Chat/Services/UserResolverService.cs

@@ -0,0 +1,35 @@
+using Foxchat.Chat.Database;
+using Foxchat.Chat.Database.Models;
+using Foxchat.Core.Federation;
+using Foxchat.Core.Models;
+using Microsoft.EntityFrameworkCore;
+
+namespace Foxchat.Chat.Services;
+
+public class UserResolverService(ILogger logger, ChatContext db, RequestSigningService requestSigningService)
+{
+    public async Task<User> ResolveUserAsync(IdentityInstance instance, string userId)
+    {
+        var user = await db.Users.FirstOrDefaultAsync(u => u.InstanceId == instance.Id && u.RemoteUserId == userId);
+        if (user != null)
+        {
+            // TODO: update user if it's been long enough
+            return user;
+        }
+
+        var userResponse = await requestSigningService.RequestAsync<Users.User>(HttpMethod.Get, instance.Domain,
+            $"/_fox/ident/users/{userId}");
+
+        user = new User
+        {
+            Instance = instance,
+            Username = userResponse.Username,
+            RemoteUserId = userResponse.Id,
+            Avatar = userResponse.AvatarUrl
+        };
+
+        db.Add(user);
+        await db.SaveChangesAsync();
+        return user;
+    }
+}