private static ISetupInstance2 GetLatestPath()

in packages/csharp/PortingAssistant/PortingAssistant.VisualStudio/VisualStudioFinder.cs [55:118]
52 lines of code
14 McCabe index (conditional complexity)

        private static ISetupInstance2 GetLatestPath()
        {
            var result = default(ISetupInstance2);
            var resultVersion = new Version(0, 0);

            try
            {
                // This code is not obvious. See the sample (link above) for reference.
                var query = (ISetupConfiguration2)GetQuery();
                var e = query.EnumAllInstances();

                int fetched;
                var instances = new ISetupInstance[1];
                do
                {
                    // Call e.Next to query for the next instance (single item or nothing returned).
                    e.Next(1, instances, out fetched);
                    if (fetched <= 0)
                    {
                        continue;
                    }

                    var instance = (ISetupInstance2)instances[0];
                    var state = instance.GetState();

                    if (!Version.TryParse(instance.GetInstallationVersion(), out var version))
                    {
                        continue;
                    }

                    // If the install was complete and a valid version, consider it.
                    if (state == InstanceState.Complete ||
                        (state.HasFlag(InstanceState.Registered) && state.HasFlag(InstanceState.NoRebootRequired)))
                    {
                        var instanceHasMSBuild = false;

                        foreach (var package in instance.GetPackages())
                        {
                            if (string.Equals(package.GetId(), "Microsoft.Component.MSBuild", StringComparison.OrdinalIgnoreCase))
                            {
                                instanceHasMSBuild = true;
                                break;
                            }
                        }

                        if (instanceHasMSBuild && instance != null && version > resultVersion)
                        {
                            result = instance;
                            resultVersion = version;
                        }
                    }
                }
                while (fetched > 0);
            }
            catch (COMException)
            {
            }
            catch (DllNotFoundException)
            {
                // This is OK, VS "15" or greater likely not installed.
            }

            return result;
        }