/* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*
*  Licensed to Elasticsearch B.V. under one or more contributor
*  license agreements. See the NOTICE file distributed with
*  this work for additional information regarding copyright
*  ownership. Elasticsearch B.V. licenses this file to you under
*  the Apache License, Version 2.0 (the "License"); you may
*  not use this file except in compliance with the License.
*  You may obtain a copy of the License at
*
* 	http://www.apache.org/licenses/LICENSE-2.0
*
*  Unless required by applicable law or agreed to in writing,
*  software distributed under the License is distributed on an
*  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
*  KIND, either express or implied.  See the License for the
*  specific language governing permissions and limitations
*  under the License.
*/
// https://raw.githubusercontent.com/dotnet/core-setup/master/src/managed/Microsoft.DotNet.PlatformAbstractions/Native/NativeMethods.Windows.cs

using System.Runtime.InteropServices;

namespace OpenSearch.Client
{
	internal static class NativeMethods
	{
		public static class Windows
		{
			// This call avoids the shimming Windows does to report old versions
			[DllImport("ntdll")]
			private static extern int RtlGetVersion(out RTL_OSVERSIONINFOEX lpVersionInformation);

			internal static string RtlGetVersion()
			{
				var osvi = new RTL_OSVERSIONINFOEX();
				osvi.dwOSVersionInfoSize = (uint)Marshal.SizeOf(osvi);
				if (RtlGetVersion(out osvi) == 0)
					return $"Microsoft Windows {osvi.dwMajorVersion}.{osvi.dwMinorVersion}.{osvi.dwBuildNumber}";

				return null;
			}

			[StructLayout(LayoutKind.Sequential)]
			internal struct RTL_OSVERSIONINFOEX
			{
				internal uint dwOSVersionInfoSize;
				internal uint dwMajorVersion;
				internal uint dwMinorVersion;
				internal uint dwBuildNumber;
				internal uint dwPlatformId;

				[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)]
				internal string szCSDVersion;
			}
		}
	}
}