add user unique id store

VsIntegration/Analytics/IUserUniqueIdStore.cs

@@ -0,0 +1,9 @@
+using System;
+
+namespace TechTalk.SpecFlow.VsIntegration.Analytics
+{
+    public interface IUserUniqueIdStore
+    {
+        Guid Get();
+    }
+}

VsIntegration/Analytics/RegistryUserUniqueIdStore.cs

@@ -0,0 +1,55 @@
+using System;
+using Microsoft.Win32;
+
+namespace TechTalk.SpecFlow.VsIntegration.Analytics
+{
+    public class RegistryUserUniqueIdStore : IUserUniqueIdStore
+    {
+        private const string UserUniqueIdPath = @"Software\TechTalk\SpecFlow\Vsix";
+        private const string UserUniqueId = @"UserUniqueId";
+        private readonly Lazy<Guid> _lazyUniqueUserId;
+
+        public RegistryUserUniqueIdStore()
+        {
+            _lazyUniqueUserId = new Lazy<Guid>(FetchFromOrCreateInRegistry);
+        }
+
+        public Guid Get()
+        {
+            return _lazyUniqueUserId.Value;
+        }
+
+        public Guid FetchFromOrCreateInRegistry()
+        {
+            var rootKey = Registry.CurrentUser;
+            var key = rootKey.OpenSubKey(UserUniqueIdPath);
+            if (key == null)
+            {
+                return CreateUniqueUserIdInRegistry();
+            }
+
+            using (key)
+            {
+                var value = key.GetValue(UserUniqueId, null) as Guid?;
+                return value ?? CreateUniqueUserIdInRegistry();
+            }
+        }
+
+        public Guid CreateUniqueUserIdInRegistry()
+        {
+            var rootKey = Registry.CurrentUser;
+            using (var key = rootKey.CreateSubKey(UserUniqueIdPath))
+            {
+                if (key == null)
+                {
+                    throw new InvalidOperationException("Could not create registry key.");
+                }
+
+                var newUserId = Guid.NewGuid();
+                key.SetValue(UserUniqueId, newUserId, RegistryValueKind.Binary);
+
+                return newUserId;
+            }
+        }
+    }
+}

VsIntegration/TechTalk.SpecFlow.VsIntegration.csproj

@@ -281,6 +281,8 @@
     <Compile Include="..\CommonAssemblyInfo.cs">
       <Link>Properties\CommonAssemblyInfo.cs</Link>
     </Compile>
+    <Compile Include="Analytics\IUserUniqueIdStore.cs" />
+    <Compile Include="Analytics\RegistryUserUniqueIdStore.cs" />
     <Compile Include="AutoComplete\CompletionCommandFilter.cs" />
     <Compile Include="AutoComplete\CustomCompletionSet.cs" />
     <Compile Include="AutoComplete\GherkinCompletionCommandFilter.cs" />