Implemented user deletion service and IUserDeleteHandler for plugins to hook into

Moonlight.ApiServer/Services/UserService.cs

@@ -0,0 +1,42 @@
+using MoonCore.Extended.Abstractions;
+using Moonlight.ApiServer.Database.Entities;
+using Moonlight.ApiServer.Interfaces;
+using Moonlight.ApiServer.Models;
+
+namespace Moonlight.ApiServer.Services;
+
+public class UserDeletionService
+{
+    private readonly IUserDeleteHandler[] Handlers;
+    private readonly DatabaseRepository<User> UserRepository;
+
+    public UserDeletionService(
+        IEnumerable<IUserDeleteHandler> handlers,
+        DatabaseRepository<User> userRepository
+    )
+    {
+        UserRepository = userRepository;
+        Handlers = handlers.ToArray();
+    }
+
+    public async Task<UserDeleteValidationResult> Validate(User user)
+    {
+        foreach (var handler in Handlers)
+        {
+            var result = await handler.Validate(user);
+
+            if (!result.IsAllowed)
+                return result;
+        }
+
+        return UserDeleteValidationResult.Allow();
+    }
+
+    public async Task Delete(User user, bool force)
+    {
+        foreach (var handler in Handlers)
+            await Delete(user, force);
+
+        await UserRepository.Remove(user);
+    }
+}