Vanara/PInvoke/NetApi32/Lm.Ext.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Vanara.Extensions;

namespace Vanara.PInvoke
{
	public static partial class NetApi32
	{
		/// <summary>Inherit from this interface for any implementation of the SERVER_INFO_XXXX structures to use the helper functions.</summary>
		public interface INetServerInfo { }

		/// <summary>The NetServerEnum function lists all servers of the specified type that are visible in a domain.</summary>
		/// <typeparam name="T">The type of the structure to have filled in for each server. This must be SERVER_INFO_100 or SERVER_INFO_101.</typeparam>
		/// <param name="netServerEnumFilter">A value that filters the server entries to return from the enumeration.</param>
		/// <param name="domain">
		/// A string that specifies the name of the domain for which a list of servers is to be returned. The domain name must be a NetBIOS
		/// domain name (for example, Microsoft). The NetServerEnum function does not support DNS-style names (for example, microsoft.com).
		/// If this parameter is NULL, the primary domain is implied.
		/// </param>
		/// <param name="level">
		/// The information level of the data requested. If this value is 0, then the method will extract all digits to form the level (e.g.
		/// SERVER_INFO_101 produces 101).
		/// </param>
		/// <returns>A managed array of the requested type.</returns>
		public static IEnumerable<T> NetServerEnum<T>(NetServerEnumFilter netServerEnumFilter = NetServerEnumFilter.SV_TYPE_WORKSTATION | NetServerEnumFilter.SV_TYPE_SERVER, string domain = null, int level = 0) where T : struct, INetServerInfo
		{
			if (level == 0) level = GetLevelFromStructure<T>();
			if (level != 100 && level != 101)
				throw new ArgumentOutOfRangeException(nameof(level), @"Only SERVER_INFO_100 or SERVER_INFO_101 are supported as valid structures.");
			var resumeHandle = IntPtr.Zero;
			var ret = NetServerEnum(null, level, out var bufptr, MAX_PREFERRED_LENGTH, out var entriesRead, out var totalEntries, netServerEnumFilter, domain, resumeHandle);
			ret.ThrowIfFailed();
			return bufptr.DangerousGetHandle().ToIEnum<T>(entriesRead);
		}

		/// <summary>The NetServerGetInfo function retrieves current configuration information for the specified server.</summary>
		/// <typeparam name="T">
		/// The type of the structure to have filled in for each server. This must be SERVER_INFO_100, SERVER_INFO_101, or SERVER_INFO_102.
		/// </typeparam>
		/// <param name="serverName">
		/// A string that specifies the name of the remote server on which the function is to execute. If this parameter is NULL, the local
		/// computer is used.
		/// </param>
		/// <param name="level">
		/// The information level of the data requested. If this value is 0, then the method will extract all digits to form the level (e.g.
		/// SERVER_INFO_101 produces 101).
		/// </param>
		/// <returns>The requested type with returned information about the server.</returns>
		public static T NetServerGetInfo<T>(string serverName, int level = 0) where T : struct, INetServerInfo
		{
			if (level == 0) level = GetLevelFromStructure<T>();
			if (level != 100 && level != 101 && level != 102)
				throw new ArgumentOutOfRangeException(nameof(level), @"Only SERVER_INFO_100, SERVER_INFO_101, or SERVER_INFO_102 are supported as valid structures.");
			var ret = NetServerGetInfo(serverName, level, out var ptr);
			ret.ThrowIfFailed();
			return ptr.DangerousGetHandle().ToStructure<T>();
		}

		private static int GetLevelFromStructure<T>()
		{
			int.TryParse(System.Text.RegularExpressions.Regex.Replace(typeof(T).Name, @"[^\d]", ""), out var i);
			return i;
		}

		private static IEnumerable<SERVER_INFO_101> GetNetworkComputerInfo(NetServerEnumFilter netServerEnumFilter = NetServerEnumFilter.SV_TYPE_WORKSTATION | NetServerEnumFilter.SV_TYPE_SERVER, string domain = null) =>
			NetServerEnum<SERVER_INFO_101>(netServerEnumFilter, domain, 101);

		private static IEnumerable<string> GetNetworkComputerNames(NetServerEnumFilter netServerEnumFilter = NetServerEnumFilter.SV_TYPE_WORKSTATION | NetServerEnumFilter.SV_TYPE_SERVER, string domain = null) =>
			NetServerEnum<SERVER_INFO_100>(netServerEnumFilter, domain, 100).Select(si => si.sv100_name);
	}
}