1 files changed, 174 insertions, 0 deletions

diff --git a/src/dtf/WixToolset.Dtf.WindowsInstaller/FeatureInstallation.cs b/src/dtf/WixToolset.Dtf.WindowsInstaller/FeatureInstallation.cs
new file mode 100644
index 00000000..aa8ffe34
--- /dev/null
+++ b/src/dtf/WixToolset.Dtf.WindowsInstaller/FeatureInstallation.cs
@@ -0,0 +1,174 @@
+// 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.Dtf.WindowsInstaller
+{
+    using System;
+    using System.Text;
+    using System.Collections.Generic;
+    using System.Diagnostics.CodeAnalysis;
+
+    /// <summary>
+    /// Represents an instance of a feature of an installed product.
+    /// </summary>
+    public class FeatureInstallation : InstallationPart
+    {
+        /// <summary>
+        /// Creates a new FeatureInstallation instance for a feature of a product.
+        /// </summary>
+        /// <param name="featureName">feature name</param>
+        /// <param name="productCode">ProductCode GUID</param>
+        public FeatureInstallation(string featureName, string productCode)
+            : base(featureName, productCode)
+        {
+            if (String.IsNullOrEmpty(featureName))
+            {
+                throw new ArgumentNullException("featureName");
+            }
+        }
+
+        /// <summary>
+        /// Gets the name of the feature.
+        /// </summary>
+        public string FeatureName
+        {
+            get
+            {
+                return this.Id;
+            }
+        }
+
+        /// <summary>
+        /// Gets the installed state of the feature.
+        /// </summary>
+        /// <remarks><p>
+        /// Win32 MSI API:
+        /// <a href="http://msdn.microsoft.com/library/en-us/msi/setup/msiqueryfeaturestate.asp">MsiQueryFeatureState</a>
+        /// </p></remarks>
+        public override InstallState State
+        {
+            get
+            {
+                int installState = NativeMethods.MsiQueryFeatureState(
+                    this.ProductCode, this.FeatureName);
+                return (InstallState) installState;
+            }
+        }
+
+        /// <summary>
+        /// Gets the parent of the feature, or null if the feature has no parent (it is a root feature).
+        /// </summary>
+        /// <remarks>
+        /// Invocation of this property may be slightly costly for products with many features,
+        /// because it involves an enumeration of all the features in the product.
+        /// </remarks>
+        public FeatureInstallation Parent
+        {
+            get
+            {
+                StringBuilder featureBuf = new StringBuilder(256);
+                StringBuilder parentBuf = new StringBuilder(256);
+                for (uint i = 0; ; i++)
+                {
+                    uint ret = NativeMethods.MsiEnumFeatures(this.ProductCode, i, featureBuf, parentBuf);
+
+                    if (ret != 0)
+                    {
+                        break;
+                    }
+
+                    if (featureBuf.ToString() == this.FeatureName)
+                    {
+                        if (parentBuf.Length > 0)
+                        {
+                            return new FeatureInstallation(parentBuf.ToString(), this.ProductCode);
+                        }
+                        else
+                        {
+                            return null;
+                        }
+                    }
+                }
+
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// Gets the usage metrics for the feature.
+        /// </summary>
+        /// <remarks><p>
+        /// If no usage metrics are recorded, the <see cref="UsageData.UseCount" /> value is 0.
+        /// </p><p>
+        /// Win32 MSI API:
+        /// <a href="http://msdn.microsoft.com/library/en-us/msi/setup/msigetfeatureusage.asp">MsiGetFeatureUsage</a>
+        /// </p></remarks>
+        public FeatureInstallation.UsageData Usage
+        {
+            get
+            {
+                uint useCount;
+                ushort useDate;
+                uint ret = NativeMethods.MsiGetFeatureUsage(
+                    this.ProductCode, this.FeatureName, out useCount, out useDate);
+                if (ret != 0)
+                {
+                    throw InstallerException.ExceptionFromReturnCode(ret);
+                }
+
+                DateTime lastUsedDate;
+                if (useCount == 0)
+                {
+                    lastUsedDate = DateTime.MinValue;
+                }
+                else
+                {
+                    lastUsedDate = new DateTime(
+                        1980 + (useDate >> 9),
+                        (useDate & 0x01FF) >> 5,
+                        (useDate & 0x001F));
+                }
+
+                return new UsageData((int) useCount, lastUsedDate);
+            }
+        }
+
+        /// <summary>
+        /// Holds data about the usage of a feature.
+        /// </summary>
+        [SuppressMessage("Microsoft.Design", "CA1034:NestedTypesShouldNotBeVisible")]
+        [SuppressMessage("Microsoft.Performance", "CA1815:OverrideEqualsAndOperatorEqualsOnValueTypes")]
+        public struct UsageData
+        {
+            private int useCount;
+            private DateTime lastUsedDate;
+
+            internal UsageData(int useCount, DateTime lastUsedDate)
+            {
+                this.useCount = useCount;
+                this.lastUsedDate = lastUsedDate;
+            }
+
+            /// <summary>
+            /// Gets count of the number of times the feature has been used.
+            /// </summary>
+            public int UseCount
+            {
+                get
+                {
+                    return this.useCount;
+                }
+            }
+
+            /// <summary>
+            /// Gets the date the feature was last used.
+            /// </summary>
+            public DateTime LastUsedDate
+            {
+                get
+                {
+                    return this.lastUsedDate;
+                }
+            }
+        }
+    }
+}