using System;
using System.Collections.Generic;
using System.Linq;
using System.Management;
using System.Text;
using System.Threading.Tasks;

namespace NX_Installation
{
    class WindowsVersion
    {
        public enum WindowsMainVersion
        {
            WindowsXP,
            WindowsServer2003,
            WindowsXP_64,
            WindowsVista,
            WindowsVista_64,
            WindowsServer2008,
            Windows7,
            Windows7_64,
            WindowsServer2008R2,
            Windows8,
            Windows8_64,
            Windows8_1,
            Windows8_1_Update1,
            Windows8_1_64,
            Windows8_1_64_Update1,
            Windows10,
            Windows10_64,
            WindowsServer2012,
            WindowsServer2016,
            Unknown
        }

        string MajorVersion { set; get; }
        string MinorVersion { set; get; }
        string Build { set; get; }

        public WindowsVersion()
        {
            string osv = OSVersion.Version.ToString();
            WinVersion(osv);
        }

        public WindowsMainVersion GetWindowsVersion()
        {
            if (Environment.Is64BitOperatingSystem)
            {
                //64bit
                if (MajorVersion == "5" & MinorVersion == "1")
                {
                    return WindowsMainVersion.WindowsXP_64;
                }
                else if (MajorVersion == "5" & MinorVersion == "2")
                {
                    return WindowsMainVersion.WindowsServer2003;
                }
                else if (MajorVersion == "6" & MinorVersion == "0" & (Build == "6000" | Build == "6002"))
                {
                    return WindowsMainVersion.WindowsVista_64;
                }
                else if (MajorVersion == "6" & MinorVersion == "0" & Build == "6001")
                {
                    return WindowsMainVersion.WindowsServer2008R2;
                }
                else if (MajorVersion == "6" & MinorVersion == "1" & (Build == "7600" | Build == "7601"))
                {
                    return WindowsMainVersion.Windows7_64;
                }
                else if (MajorVersion == "6" & MinorVersion == "1" & Build == "7600")
                {
                    return WindowsMainVersion.WindowsServer2008R2;
                }
                else if (MajorVersion == "6" & MinorVersion == "2")
                {
                    return WindowsMainVersion.Windows8_64;
                }
                else if (MajorVersion == "6" & MinorVersion == "3" & Build == "9200")
                {
                    return WindowsMainVersion.Windows8_1_64;
                }
                else if (MajorVersion == "6" & MinorVersion == "3" & Build == "9600")
                {
                    return WindowsMainVersion.Windows8_1_64_Update1;
                }
                else if (MajorVersion == "10" & MinorVersion == "0")
                {
                    return WindowsMainVersion.Windows10_64;
                }
                else if (MajorVersion == "10" & MinorVersion == "0" & Build == "14393")
                {
                    return WindowsMainVersion.WindowsServer2016;
                }
                else
                {
                    return WindowsMainVersion.Unknown;
                }
            }
            else
            {
                //32bit
                if (MajorVersion == "5" & MinorVersion == "1")
                {
                    return WindowsMainVersion.WindowsXP;
                }
                else if (MajorVersion == "6" & MinorVersion == "0" & (Build == "6000" | Build == "6002"))
                {
                    return WindowsMainVersion.WindowsVista;
                }
                else if (MajorVersion == "6" & MinorVersion == "1" & (Build == "7600" | Build == "7601"))
                {
                    return WindowsMainVersion.Windows7;
                }
                else if (MajorVersion == "6" & MinorVersion == "2")
                {
                    return WindowsMainVersion.Windows8;
                }
                else if (MajorVersion == "6" & MinorVersion == "3" & Build == "9200")
                {
                    return WindowsMainVersion.Windows8_1;
                }
                else if (MajorVersion == "6" & MinorVersion == "3" & Build == "9600")
                {
                    return WindowsMainVersion.Windows8_1_Update1;
                }
                else if (MajorVersion == "10" & MinorVersion == "0")
                {
                    return WindowsMainVersion.Windows10;
                }
                else
                {
                    return WindowsMainVersion.Unknown;
                }
            }
        }

        private void WinVersion(string osv)
        {
            if (string.IsNullOrEmpty(osv))
            {
                MajorVersion = "Unknown";
            }
            else
            {
                MajorVersion = osv.Remove(osv.IndexOf("."));
                osv = osv.Remove(0, osv.IndexOf(".") + 1);
                MinorVersion = osv.Remove(osv.IndexOf("."));
                Build = osv.Remove(0, osv.IndexOf(".") + 1);
            }
        }
    }

    /// <summary>
    /// Stellt Informationen über das Betriebssystem Bereit.
    /// </summary>
    public static class OSVersion
    {
        /// <summary>
        /// Initialisiert die Werte der Eigenschaften.
        /// </summary>
        static void init()
        {
            using (var mos = new ManagementObjectSearcher("SELECT Caption, Version FROM Win32_OperatingSystem"))
            {
                var attribs = mos.Get().OfType<ManagementObject>();
                caption = attribs.FirstOrDefault().GetPropertyValue("Caption").ToString() ?? "Unknown";
                version = new Version((attribs.FirstOrDefault().GetPropertyValue("Version") ?? "0.0.0.0").ToString());
            }
        }

        static string caption = null;
        static Version version = null;

        /// <summary>
        /// Ruft den Namen des Betriebssystems ab.
        /// </summary>
        public static string Caption
        {
            get
            {
                if (caption == null)
                    init();
                return caption;
            }
        }
        /// <summary>
        /// Ruft die Versionsnummer des Betriebssystems ab.
        /// </summary>
        public static Version Version
        {
            get
            {
                if (version == null)
                    init();
                return version;
            }
        }
    }

}