Release code if code is rejected by another plugin

Boot.Codes.csproj

@@ -7,8 +7,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <!--ProjectReference Include="../Impostor/src/Impostor.Api/Impostor.Api.csproj" /-->
-    <PackageReference Include="Impostor.Api" Version="1.9.1" />
+    <!--TODO switch back to mainline if Impostor 1.9.2 is released -->
+    <ProjectReference Include="../Impostor/src/Impostor.Api/Impostor.Api.csproj" />
+    <!--PackageReference Include="Impostor.Api" Version="1.9.1" /-->
     <PackageReference Include="System.Resources.Extensions" Version="8.0.0" />
   </ItemGroup>
 

BootCodesPlugin.cs

@@ -1,4 +1,6 @@
 using System.Threading.Tasks;
+using Boot.Codes.Handlers;
+using Impostor.Api.Events.Managers;
 using Impostor.Api.Plugins;
 using Microsoft.Extensions.Logging;
 
@@ -11,10 +13,11 @@ public class BootCodesPlugin : PluginBase
 
         private readonly IGameCodeManager _manager;
 
-        public BootCodesPlugin(ILogger<BootCodesPlugin> logger, IGameCodeManager manager)
+        public BootCodesPlugin(ILogger<BootCodesPlugin> logger, IGameCodeManager manager, IEventManager eventManager, GameEventListener eventListener)
         {
             this._logger = logger;
             this._manager = manager;
+            eventManager.RegisterListener(eventListener);
         }
 
         public override ValueTask EnableAsync()

BootCodesPluginStartup.cs

@@ -1,6 +1,7 @@
 using Impostor.Api.Plugins;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.DependencyInjection;
+using Boot.Codes.Handlers;
 
 namespace Boot.Codes
 {
@@ -11,6 +12,7 @@ public void ConfigureHost(IHostBuilder host) { }
         public void ConfigureServices(IServiceCollection services)
         {
             services.AddSingleton<IGameCodeManager, GameCodeManager>();
+            services.AddSingleton<GameEventListener>();
         }
     }
 }

GameCodeManager.cs

@@ -46,8 +46,6 @@ public GameCodeManager(ILogger<GameCodeManager> logger, IGameCodeFactory codeFac
 
             this._codes = validCodes;
             this._inUse = new HashSet<GameCode>();
-
-            eventManager.RegisterListener(new GameEventListener(this));
         }
 
         private IEnumerable<GameCode> Read()
@@ -129,9 +127,9 @@ public void Release(GameCode code)
         {
             lock (_sync)
             {
-                if (!_inUse.Contains(code)) return; // generated by the factory
-                _inUse.Remove(code);
-                _codes.Add(code);
+                if (_inUse.Remove(code)) {
+                    _codes.Add(code);
+                }
             }
         }
     }

Handlers/GameEventListener.cs

@@ -1,22 +1,49 @@
+using System.Collections.Generic;
 using Impostor.Api.Events;
+using Impostor.Api.Games;
+using Microsoft.Extensions.Logging;
 
 namespace Boot.Codes.Handlers
 {
     public class GameEventListener : IEventListener
     {
         private readonly IGameCodeManager _gameCodeManager;
+        private readonly ILogger<GameEventListener> _logger;
+        private readonly Dictionary<int, GameCode> _assignmentMap = new();
 
-        public GameEventListener(IGameCodeManager gameCodeManager)
+        public GameEventListener(IGameCodeManager gameCodeManager, ILogger<GameEventListener> logger)
         {
-            this._gameCodeManager = gameCodeManager;
+            _gameCodeManager = gameCodeManager;
+            _logger = logger;
         }
 
         // NOTE: if you want to override the results of Boot.Codes, register an event at a lower priority
-
         [EventListener(EventPriority.Highest)]
-        public void OnGameCreated(IGameCreationEvent e) => e.GameCode = _gameCodeManager.Get();
+        public void OnGameCreation(IGameCreationEvent e)
+        {
+            var code = _gameCodeManager.Get();
+            e.GameCode = code;
+            if (e.Client != null)
+            {
+                _assignmentMap[e.Client.Id] = code;
+            }
+        }
 
-        [EventListener(EventPriority.Highest)]
+        [EventListener]
+        public void OnGameCreated(IGameCreatedEvent e)
+        {
+            if (e.Host != null)
+            {
+                var hostId = e.Host.Id;
+                if (_assignmentMap.Remove(hostId, out var expectedCode) && expectedCode != e.Game.Code)
+                {
+                    _logger.LogInformation("Boot.Codes provided code was overridden in game {Code}", e.Game.Code);
+                    _gameCodeManager.Release(expectedCode);
+                }
+            }
+        }
+
+        [EventListener]
         public void OnGameDestroyed(IGameDestroyedEvent e) => _gameCodeManager.Release(e.Game.Code);
     }
 }