Add ICurrentApp to expose the current app id to apps

src/AppModel/NetDaemon.AppModel.Tests/Context/ApplicationContextTests.cs

@@ -15,4 +15,16 @@ public async Task TestApplicationContextIsDisposedMultipleTimesNotThrowsExceptio
         await applicationContext.DisposeAsync();
         await applicationContext.DisposeAsync();
     }
+
+    [Fact]
+    public void TestApplicationContextExposesAppFactoryIdAsCurrentApp()
+    {
+        var serviceProvider = new ServiceCollection().BuildServiceProvider();
+        var appFactory = new Mock<IAppFactory>();
+        appFactory.SetupGet(f => f.Id).Returns("MyApps.SomeApp");
+
+        ICurrentApp currentApp = new ApplicationContext(serviceProvider, appFactory.Object);
+
+        currentApp.Id.Should().Be("MyApps.SomeApp");
+    }
 }

src/AppModel/NetDaemon.AppModel.Tests/Context/CurrentAppTests.cs

@@ -0,0 +1,36 @@
+using NetDaemon.AppModel.Internal;
+
+namespace NetDaemon.AppModel.Tests.Context;
+
+public class CurrentAppTests
+{
+    [Fact]
+    public async Task AppCanInjectCurrentAppAndGetsItsOwnId()
+    {
+        // ARRANGE
+        var serviceCollection = new ServiceCollection();
+        serviceCollection.AddLogging();
+        serviceCollection.AddNetDaemonApp<AppThatCapturesItsId>();
+
+        var serviceProvider = serviceCollection.BuildServiceProvider();
+        var appModelContext = serviceProvider.GetRequiredService<IAppModelContext>();
+
+        // ACT
+        await appModelContext.InitializeAsync(CancellationToken.None);
+
+        // ASSERT
+        var application = (Application)appModelContext.Applications.Single();
+        var instance = (AppThatCapturesItsId)application.ApplicationContext!.Instance!;
+        instance.CapturedId.Should().Be(typeof(AppThatCapturesItsId).FullName);
+    }
+
+    private sealed class AppThatCapturesItsId
+    {
+        public AppThatCapturesItsId(ICurrentApp currentApp)
+        {
+            CapturedId = currentApp.Id;
+        }
+
+        public string CapturedId { get; }
+    }
+}

src/AppModel/NetDaemon.AppModel/Common/Extensions/ServiceCollectionExtension.cs

@@ -111,7 +111,8 @@ private static IServiceCollection AddScopedAppServices(this IServiceCollection s
     {
         services
             .AddScoped<ApplicationScope>()
-            .AddScoped(s => s.GetRequiredService<ApplicationScope>().ApplicationContext);
+            .AddScoped(s => s.GetRequiredService<ApplicationScope>().ApplicationContext)
+            .AddScoped<ICurrentApp>(s => s.GetRequiredService<ApplicationContext>());
         return services;
     }
 

src/AppModel/NetDaemon.AppModel/Common/ICurrentApp.cs

@@ -0,0 +1,19 @@
+namespace NetDaemon.AppModel;
+
+/// <summary>
+///     Provides information about the app that owns the current dependency injection scope.
+/// </summary>
+/// <remarks>
+///     Resolve this from an app's constructor, or from any service registered in the app's
+///     scope, to discover which app is being instantiated - for example to select per-app
+///     configuration or logging.
+/// </remarks>
+public interface ICurrentApp
+{
+    /// <summary>
+    ///     Gets the unique id of the app that owns the current scope. This is the same id
+    ///     NetDaemon uses elsewhere: the value of <see cref="NetDaemonAppAttribute.Id"/> when
+    ///     set, otherwise the full name of the app type.
+    /// </summary>
+    string Id { get; }
+}

src/AppModel/NetDaemon.AppModel/Internal/Context/ApplicationContext.cs

@@ -2,7 +2,7 @@
 
 namespace NetDaemon.AppModel.Internal;
 
-internal sealed class ApplicationContext : IAsyncDisposable
+internal sealed class ApplicationContext : IAsyncDisposable, ICurrentApp
 {
     private readonly CancellationTokenSource _cancelTokenSource = new();
     private readonly IServiceScope? _serviceScope;
@@ -21,9 +21,13 @@ public ApplicationContext(IServiceProvider serviceProvider, IAppFactory appFacto
         if (appScope != null) appScope.ApplicationContext = this;
 
         // Now create the actual app from the new scope
+        Id = appFactory.Id;
         Instance = appFactory.Create(scopedProvider);
     }
 
+    /// <inheritdoc />
+    public string Id { get; }
+
     public object? Instance { get; private set; }
 
     public async Task InitializeAsync()