Introduce WixToolsetServiceProvider

Using a service provider allows all of WixToolset.Core's internal
functionality to be abstracted behind interfaces in WixToolset.Extensibility.
The service provide can also control what interfaces are singletons.

1 files changed, 47 insertions, 0 deletions

diff --git a/src/WixToolset.Core/WixToolsetServiceProvider.cs b/src/WixToolset.Core/WixToolsetServiceProvider.cs
new file mode 100644
index 00000000..c073c32b
--- /dev/null
+++ b/src/WixToolset.Core/WixToolsetServiceProvider.cs
@@ -0,0 +1,47 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Core
+{
+    using System;
+    using WixToolset.Extensibility;
+    using WixToolset.Extensibility.Services;
+
+    public class WixToolsetServiceProvider : IServiceProvider
+    {
+        private ExtensionManager extensionManager;
+
+        public object GetService(Type serviceType)
+        {
+            if (serviceType == null) throw new ArgumentNullException(nameof(serviceType));
+
+            // Transients.
+            if (serviceType == typeof(IBindContext))
+            {
+                return new BindContext(this);
+            }
+
+            if (serviceType == typeof(IInscribeContext))
+            {
+                return new InscribeContext(this);
+            }
+
+            if (serviceType == typeof(ICommandLineContext))
+            {
+                return new CommandLineContext(this);
+            }
+
+            if (serviceType == typeof(ICommandLine))
+            {
+                return new CommandLine();
+            }
+
+            // Singletons.
+            if (serviceType == typeof(IExtensionManager))
+            {
+                return extensionManager = extensionManager ?? new ExtensionManager();
+            }
+
+            throw new ArgumentException($"Unknown service type: {serviceType.Name}", nameof(serviceType));
+        }
+    }
+}