Adding initial auction system

Services/AuctionService.cs

@@ -0,0 +1,31 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using GameAuthApi.Models;
+using Microsoft.Extensions.Configuration;
+using MongoDB.Driver;
+
+namespace GameAuthApi.Services;
+
+public class AuctionService
+{
+    private readonly IMongoCollection<Auction> _auctions;
+
+    public AuctionService(IConfiguration config)
+    {
+        var client = new MongoClient(config["MongoDB:ConnectionString"]);
+        var db = client.GetDatabase(config["MongoDB:DatabaseName"]);
+        _auctions = db.GetCollection<Auction>("Auctions");
+    }
+
+    public virtual async Task CreateAsync(Auction auction) =>
+        await _auctions.InsertOneAsync(auction);
+
+    public virtual async Task<Auction> GetByIdAsync(string id) =>
+        await _auctions.Find(a => a.Id == id).FirstOrDefaultAsync();
+
+    public virtual async Task UpdateAsync(Auction auction) =>
+        await _auctions.ReplaceOneAsync(a => a.Id == auction.Id, auction);
+
+    public virtual async Task<List<Auction>> GetActiveAsync() =>
+        await _auctions.Find(a => !a.IsClosed).ToListAsync();
+}