move card storage/web server handlers to separate files

AMNet.Server/CardPresenter.cs

@@ -0,0 +1,73 @@
+using System;
+using System.Globalization;
+
+namespace AMNet.Server;
+
+/// <summary>
+/// Represents a storage location to load/read cards from
+/// </summary>
+public class CardPresenter
+{
+    private readonly object _cardLock = new();
+    private StoredCard _currentCard;
+    
+    public record StoredCard(byte[] Value, string OriginalValue, long ExpiresAt)
+    {
+        public bool Expired => Environment.TickCount64 >= ExpiresAt;
+    }
+
+    /// <summary>
+    /// Returns the currently active card without clearing it
+    /// </summary>
+    public StoredCard PeekActiveCard()
+    {
+        lock (_cardLock)
+        {
+            return _currentCard;
+        }
+    }
+
+    public StoredCard TakeActiveCard()
+    {
+        lock (_cardLock)
+        {
+            var card = _currentCard;
+            _currentCard = null;
+
+            return card;
+        }
+    }
+
+    /// <summary>
+    /// Sets the card
+    /// </summary>
+    /// <param name="cardId">The card id to set</param>
+    /// <param name="validFor">How long the card should be presented to the game for in milliseconds</param>
+    /// <returns>Whether the card was set successfully</returns>
+    public bool SetCard(string cardId, long validFor = 5000)
+    {
+        // ensure the matrix code is 20-digits long, otherwise pad with zeros
+        var matrixCode = cardId.PadLeft(20, '0');
+        var bytes = new byte[10];
+
+        for (var i = 0; i < bytes.Length; i++)
+        {
+            var value = matrixCode.Substring(i * 2, 2);
+            if (byte.TryParse(value, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out var b))
+            {
+                bytes[i] = b;
+            }
+            else
+            {
+                return false;
+            }
+        }
+
+        lock (_cardLock)
+        {
+            _currentCard = new StoredCard(bytes, matrixCode, Environment.TickCount64 + validFor);
+        }
+
+        return true;
+    }
+}

AMNet.Server/Config.cs

@@ -0,0 +1,31 @@
+using System;
+using Windows.Win32;
+using Windows.Win32.Foundation;
+
+namespace AMNet.Server;
+
+internal static class Config
+{
+    private const string ConfigFileName = @".\segatools.ini";
+
+    internal const string IOSection = "aimeio";
+
+    static Config()
+    {
+        GameId = ReadKey(IOSection, "gameId", 4);
+        ServerName = ReadKey(IOSection, "serverName", 26, Environment.MachineName);
+    }
+    
+    public static string GameId { get; }
+    public static string ServerName { get; }
+    
+    internal static unsafe string ReadKey(string section, string key, uint maxLength, string @default = null)
+    {
+        var buffer = stackalloc char[(int)maxLength + 1];
+        var bufferStr = new PWSTR(buffer);
+
+        PInvoke.GetPrivateProfileString(section, key, @default ?? string.Empty, bufferStr, maxLength, ConfigFileName);
+
+        return bufferStr.ToString();
+    }
+}

AMNet.Server/DllMain.cs

@@ -1,32 +1,18 @@
-using System;
-using System.Globalization;
 using System.Linq;
 using System.Runtime.InteropServices;
-using System.Text.Json;
 using System.Threading;
 using Windows.Win32;
-using Windows.Win32.Foundation;
 using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Hosting;
-using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 
 namespace AMNet.Server;
 
 public static class DllMain
 {
-    private const int ApiVersion = 1;
     private const string WebAddress = "http://card.ppc.moe";
 
-    private static ILogger _serverLogger;
-
-    private static string[] _serverAddresses;
-    private static string _serverName;
-    private static string _gameId;
-
-    private static (byte[] IdBytes, string OriginalId, long Expires)? _currentCard;
-
-    private static readonly object _cardLock = new();
+    private static WebApplication _app;
 
     static DllMain()
     {
@@ -39,105 +25,27 @@ public static class DllMain
     [UnmanagedCallersOnly(EntryPoint = "aime_io_init")]
     public static int Init()
     {
-        LoadConfiguration();
+        var addresses = Config.ReadKey(Config.IOSection, "serverAddress", 1024, "http://+:6070").Split(';');
 
-        var builder = WebServer.BuildServer();
-        builder.WebHost.UseUrls(_serverAddresses);
+        _app = WebServer.BuildServer(addresses);
 
-        var app = builder.Build();
-
-        _serverLogger = app.Logger;
-
-        app.UseCors();
-        app.MapGet("/amnet/info", () => Results.Ok(new SystemState(ApiVersion, _gameId, _serverName)));
-        app.MapPost("/amnet/signin", async ctx =>
+        CancellationTokenRegistration? cancellationRegistration = null;
+        cancellationRegistration = _app.Lifetime.ApplicationStarted.Register(() =>
         {
-            CardReadRequest request;
+            _app.Logger.LogInformation("AMNet Server ({gameId}) started successfully.", Config.GameId);
+            _app.Logger.LogInformation("Visit {addr} from a mobile device on the same network to get started.", WebAddress);
 
-            try
-            {
-                request = await ctx.Request.ReadFromJsonAsync<CardReadRequest>();
-            }
-            catch (JsonException e)
-            {
-                ctx.Response.StatusCode = 400;
-                await ctx.Response.WriteAsync(e.Message);
-
-                return;
-            }
-
-            if (string.IsNullOrEmpty(request?.MatrixCode))
-            {
-                ctx.Response.StatusCode = 400;
-                await ctx.Response.WriteAsync("Card id not provided.");
-                return;
-            }
-
-            if (request.MatrixCode.Length is 0 or < 20)
-            {
-                ctx.Response.StatusCode = 422;
-                await ctx.Response.WriteAsync("Invalid card id length.");
-                return;
-            }
-
-            if (request.MatrixCode.Any(x => !char.IsNumber(x)))
-            {
-                ctx.Response.StatusCode = 422;
-                await ctx.Response.WriteAsync("Invalid card id format.");
-                return;
-            }
-
-            lock (_cardLock)
-            {
-                // ratelimit check
-                if (_currentCard?.Expires > Environment.TickCount64)
-                {
-                    ctx.Response.StatusCode = 429;
-                    ctx.Response.Headers.RetryAfter = ((int)TimeSpan.FromMilliseconds(_currentCard.Value.Expires - Environment.TickCount64).TotalSeconds).ToString();
-                    return;
-                }
-
-                // ensure the matrix code is 20-digits long, otherwise pad with zeros
-                var matrixCode = request.MatrixCode.PadLeft(20, '0');
-                var bytes = new byte[10];
-
-                for (var i = 0; i < 10; i++)
-                {
-                    var value = matrixCode.Substring(i * 2, 2);
-                    bytes[i] = byte.Parse(value, NumberStyles.HexNumber);
-                }
-
-                // it's called a tick count, but it uses milliseconds despite having a unit of time called a tick???
-                _currentCard = (bytes, matrixCode, Environment.TickCount64 + 5000);
-            }
-
-            ctx.Response.StatusCode = 202;
+            // ReSharper disable once AccessToModifiedClosure
+            cancellationRegistration?.Dispose();
         });
 
-        CancellationTokenRegistration cancellationRegistration = default;
-        cancellationRegistration = app.Lifetime.ApplicationStarted.Register(() =>
-        {
-            _serverLogger.LogInformation("AMNet Server ({gameId}) started successfully.", _gameId);
-            _serverLogger.LogInformation("Visit {addr} from a mobile device on the same network to get started.", WebAddress);
-
-            cancellationRegistration.Dispose();
-        });
-
-        app.RunAsync();
+        _app.RunAsync();
         return 0;
     }
 
     [UnmanagedCallersOnly(EntryPoint = "aime_io_nfc_poll")]
     public static int NfcPoll(byte unitNo)
     {
-        if (_currentCard.HasValue && _currentCard.Value.Expires < Environment.TickCount64)
-        {
-            lock (_cardLock)
-            {
-                _currentCard = null;
-            }
-        }
-
         // there's no polling here (handled by the webserver)
         return 0;
     }
@@ -145,62 +53,34 @@ public static class DllMain
     [UnmanagedCallersOnly(EntryPoint = "aime_io_nfc_get_aime_id")]
     public static int GetAimeId(byte unitNo, nint luid, nint luidSize)
     {
-        lock (_cardLock)
+        if (unitNo != 0)
         {
-            if (unitNo != 0 || _currentCard == null)
-            {
-                return 1;
-            }
-
-            if (_currentCard.Value.Expires < Environment.TickCount64)
-            {
-                _serverLogger.LogWarning("Submitted card id expired before it could be read.");
-                _currentCard = null;
-
-                return 1;
-            }
-
-            Marshal.Copy(_currentCard.Value.IdBytes, 0, luid, (int)luidSize);
-
-            _serverLogger.LogInformation("Card read in: {0}", string.Join(" ", Enumerable.Range(0, 5).Select(x => _currentCard.Value.OriginalId.Substring(x * 4, 4))));
-            _currentCard = null;
+            return 1;
         }
 
-        return 0;
+        var card = _app.Services.GetRequiredService<CardPresenter>().TakeActiveCard();
+        if (card?.Expired != false)
+        {
+            return 1;
+        }
+
+        try
+        {
+            Marshal.Copy(card.Value, 0, luid, (int)luidSize);
+            return 0;
+        }
+        finally
+        {
+            _app.Logger.LogInformation("Card read in: {0}", string.Join(" ", Enumerable.Range(0, 5).Select(x => card.OriginalValue.Substring(x * 4, 4))));
+        }
     }
 
     [UnmanagedCallersOnly(EntryPoint = "aime_io_nfc_get_felica_id")]
-    public static unsafe int GetFelicaId(byte unitNo, ulong* idm)
-    {
-        // felica not supported
-        return 1;
-    }
+    public static unsafe int GetFelicaId(byte unitNo, ulong* idm) => 1; // felica not supported
 
     [UnmanagedCallersOnly(EntryPoint = "aime_io_led_set_color")]
     public static void SetLedColour(byte unitNo, byte r, byte g, byte b)
     {
         // do nothing
     }
-
-    private static unsafe void LoadConfiguration()
-    {
-        const string configFileName = @".\segatools.ini";
-
-        var gameId = stackalloc char[5];
-        var gameIdStr = new PWSTR(gameId);
-
-        var serverName = stackalloc char[64];
-        var serverNameStr = new PWSTR(serverName);
-
-        var serverAddress = stackalloc char[1024];
-        var serverAddressStr = new PWSTR(serverAddress);
-
-        PInvoke.GetPrivateProfileString("aimeio", "gameId", string.Empty, gameIdStr, 5, configFileName);
-        PInvoke.GetPrivateProfileString("aimeio", "serverName", Environment.MachineName, serverNameStr, 64, configFileName);
-        PInvoke.GetPrivateProfileString("aimeio", "serverAddress", "http://+:6070", serverAddressStr, 1024, configFileName);
-
-        _gameId = gameIdStr.ToString();
-        _serverName = serverNameStr.ToString();
-        _serverAddresses = serverAddressStr.ToString().Split(';');
-    }
 }

AMNet.Server/WebServer.cs

@@ -1,5 +1,16 @@
 using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Net;
+using System.Net.NetworkInformation;
+using System.Net.Sockets;
+using System.Text.Json;
+using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 
@@ -7,10 +18,14 @@ namespace AMNet.Server;
 
 internal static class WebServer
 {
-    public static WebApplicationBuilder BuildServer()
+    private const int ApiVersion = 1;
+
+    public static WebApplication BuildServer(params string[] listenAddresses)
     {
         var builder = WebApplication.CreateSlimBuilder([]);
 
+        builder.WebHost.UseUrls(listenAddresses);
+
         builder.Logging.ClearProviders();
         builder.Logging.AddSimpleConsole(o =>
         {
@@ -39,6 +54,67 @@ internal static class WebServer
             options.SerializerOptions.TypeInfoResolverChain.Insert(0, SerializerContext.Default);
         });
 
-        return builder;
+        builder.Services.AddSingleton<CardPresenter>();
+
+        var app = builder.Build();
+        
+        app.UseCors();
+        app.MapGet("/amnet/info", () => Results.Ok(new SystemState(ApiVersion, Config.GameId, Config.ServerName)));
+        app.MapPost("/amnet/signin", ProcessCard);
+
+        return app;
+    }
+    
+    private static async Task ProcessCard(HttpContext ctx)
+    {
+        CardReadRequest request;
+
+        try
+        {
+            request = await ctx.Request.ReadFromJsonAsync<CardReadRequest>();
+        }
+        catch (JsonException e)
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsync(e.Message);
+
+            return;
+        }
+
+        if (string.IsNullOrEmpty(request?.MatrixCode))
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsync("Card id not provided.");
+            return;
+        }
+
+        if (request.MatrixCode.Length is 0 or < 20)
+        {
+            ctx.Response.StatusCode = 422;
+            await ctx.Response.WriteAsync("Invalid card id length.");
+            return;
+        }
+
+        var cardPresenter = ctx.RequestServices.GetRequiredService<CardPresenter>();
+        var currentCard = cardPresenter.PeekActiveCard();
+
+        if (currentCard?.Expired == false)
+        {
+            var timeLeft = Math.Ceiling(TimeSpan.FromMilliseconds(currentCard.ExpiresAt - Environment.TickCount64).TotalSeconds);
+
+            ctx.Response.StatusCode = 429;
+            ctx.Response.Headers.RetryAfter = timeLeft.ToString(CultureInfo.InvariantCulture);
+            return;
+        }
+
+        if (cardPresenter.SetCard(request.MatrixCode))
+        {
+            ctx.Response.StatusCode = 202;
+        }
+        else
+        {
+            ctx.Response.StatusCode = 422;
+            await ctx.Response.WriteAsync("Invalid card id format.");
+        }
     }
 }