fixed actor integration (#28)

src/DrawTogether.UI/Server/Services/AkkaService.cs

@@ -9,6 +9,7 @@
 using System.Threading.Tasks;
 using Akka.Actor;
 using Akka.DependencyInjection;
+using Akka.Hosting;
 using DrawTogether.UI.Server.Actors;
 using DrawTogether.UI.Shared.Connectivity;
 using Microsoft.Extensions.DependencyInjection;
@@ -21,65 +22,17 @@ namespace DrawTogether.UI.Server.Services
     /// </summary>
     public static class AkkaExtensions
     {
-        public static void AddAkka(this IServiceCollection services)
+        public static void AddDrawTogetherAkka(this IServiceCollection services)
         {
             // creates an instance of the ISignalRProcessor that can be handled by SignalR
-            services.AddSingleton<IDrawSessionHandler, AkkaService>();
-
-            // starts the IHostedService, which creates the ActorSystem and actors
-            services.AddHostedService<AkkaService>(sp => (AkkaService)sp.GetRequiredService<IDrawSessionHandler>());
-        }
-    }
-
-    /// <summary>
-    /// Runs in the background of Server process. Hosts <see cref="ActorSystem"/> responsible for powering
-    /// actors that track session state data.
-    /// </summary>
-    public sealed class AkkaService : IHostedService, IDrawSessionHandler
-    {
-        private readonly IServiceProvider _serviceProvider;
-        private readonly IHostApplicationLifetime _applicationLifetime;
-
-        private ActorSystem _system;
-        private IActorRef _paintManager;
-
-        public AkkaService(IServiceProvider serviceProvider, IHostApplicationLifetime applicationLifetime)
-        {
-            _serviceProvider = serviceProvider;
-            _applicationLifetime = applicationLifetime;
-        }
-
-        public Task StartAsync(CancellationToken cancellationToken)
-        {
-            // need this for Akka.NET DI
-            var spSetup = ServiceProviderSetup.Create(_serviceProvider);
-
-            // need this for HOCON (when we actually need it)
-            var bootstrapSetup = BootstrapSetup.Create();
-
-            var actorSystemSetup = spSetup.And(bootstrapSetup);
-
-            _system = ActorSystem.Create("PaintSys", actorSystemSetup);
-            _paintManager = _system.ActorOf(Props.Create(() => new PaintInstanceManager()), "paint");
-
-            // mutually assured destruction
-            _system.WhenTerminated.ContinueWith(tr =>
+            services.AddAkka("DrawTogether", (builder, sp) =>
             {
-                _applicationLifetime.StopApplication();
+                builder.WithActors((system, registry, resolver) =>
+                {
+                    var paintActor = system.ActorOf(Props.Create(() => new PaintInstanceManager()), "paint");
+                    registry.Register<PaintInstanceManager>(paintActor);
+                });
             });
-
-            return Task.CompletedTask;
-        }
-
-        public async Task StopAsync(CancellationToken cancellationToken)
-        {
-            // force ActorSystem to shut down
-            await _system.Terminate();
-        }
-
-        public void Handle(PaintSessionProtocol.IPaintSessionMessage msg)
-        {
-            _paintManager.Tell(msg);
         }
     }
 }

src/DrawTogether.UI/Server/Services/IDrawSessionHandler.cs

@@ -1,5 +1,8 @@
 using System.Collections.Generic;
 using System.Linq;
+using Akka.Actor;
+using Akka.Hosting;
+using DrawTogether.UI.Server.Actors;
 using static DrawTogether.UI.Shared.Connectivity.PaintSessionProtocol;
 
 namespace DrawTogether.UI.Server.Services
@@ -11,4 +14,19 @@ public interface IDrawSessionHandler
     {
         void Handle(IPaintSessionMessage msg);
     }
+
+    public sealed class DrawSessionHandler : IDrawSessionHandler
+    {
+        private readonly IActorRef _paintInstanceManager;
+
+        public DrawSessionHandler(IRequiredActor<PaintInstanceManager> paintInstanceManager)
+        {
+            _paintInstanceManager = paintInstanceManager.GetAsync().Result;
+        }
+
+        public void Handle(IPaintSessionMessage msg)
+        {
+            _paintInstanceManager.Tell(msg);
+        }
+    }
 }

src/DrawTogether.UI/Server/Startup.cs

@@ -29,9 +29,10 @@ public void ConfigureServices(IServiceCollection services)
         {
             services.AddSingleton<IPaintSessionGenerator, GuidPaintSessionGenerator>();
             services.AddSingleton<IUserIdProvider, RandomNameService>();
-            services.AddAkka();
+            services.AddDrawTogetherAkka();
             services.AddTransient<IDrawHubHandler, DrawHubHandler>();
-            services.AddSignalR().AddJsonProtocol();
+            services.AddSingleton<IDrawSessionHandler, DrawSessionHandler>();
+            services.AddSignalR();
             services.AddServerSideBlazor();
             services.AddControllersWithViews();
             services.AddRazorPages();