Adding chat system

Services/ChatService.cs

@@ -0,0 +1,28 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using GameAuthApi.Models;
+using Microsoft.Extensions.Configuration;
+using MongoDB.Driver;
+
+namespace GameAuthApi.Services;
+
+public class ChatService
+{
+    private readonly IMongoCollection<ChatMessage> _messages;
+
+    public ChatService(IConfiguration config)
+    {
+        var client = new MongoClient(config["MongoDB:ConnectionString"]);
+        var db = client.GetDatabase(config["MongoDB:DatabaseName"]);
+        _messages = db.GetCollection<ChatMessage>("ChatMessages");
+    }
+
+    public virtual async Task CreateAsync(ChatMessage msg) =>
+        await _messages.InsertOneAsync(msg);
+
+    public virtual async Task<List<ChatMessage>> GetRecentAsync(int count) =>
+        await _messages.Find(_ => true)
+            .SortByDescending(m => m.Timestamp)
+            .Limit(count)
+            .ToListAsync();
+}