using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Win32;

namespace Eugen.ESystem
{
    /// <summary>
	/// Description of Registry.
	/// </summary>
    public class Registry
    {
        #region Version und Copyright
        // Version und Copyright
        static string dllName = Path.GetFileNameWithoutExtension(System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase); //Den Programmnamen auslesen
        static string dllVersion = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version.ToString();
        static object[] attributes = Assembly.GetExecutingAssembly().GetCustomAttributes(typeof(AssemblyCopyrightAttribute), false);
        static string copyright = GenerateCopyright();

        //Assembly Datum und Zeit
        static DateTime value = AssemblyDateTime();
        static string date = value.ToShortDateString();
        static string time = value.ToLongTimeString();

        private static DateTime AssemblyDateTime()
        {
            var version = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version;
            var buildDateTime = new DateTime(2000, 1, 1).Add(new TimeSpan(TimeSpan.TicksPerDay * version.Build + TimeSpan.TicksPerSecond * 2 * version.Revision));
            //Tage seit dem 1. Januar 2000 und Sekunden seit Mitternacht, (multiplizier mit 2 ergibt das Original)
            return buildDateTime;
        }

        private static string CurrentYear()
        {
            DateTime dtn = DateTime.Now;
            return dtn.Year.ToString();
        }

        private static string StartYear()
        {
            string startYear = "";
            if (((AssemblyCopyrightAttribute)attributes[0]).Copyright.Contains("Copyright © "))
            {
                startYear = ((AssemblyCopyrightAttribute)attributes[0]).Copyright.Replace("Copyright © ", "");
                while (startYear.StartsWith(" "))
                {
                    startYear = startYear.Remove(0, 1);
                }

                if (startYear.Contains("-"))
                {
                    startYear = startYear.Remove(startYear.IndexOf("-"));
                }
                else
                {
                    startYear = startYear.Remove(startYear.IndexOf(" "));
                }
                return startYear;
            }
            else
            {
                DateTime dtn = DateTime.Now;
                return dtn.Year.ToString();
            }
        }

        private static string GenerateCopyright()
        {
            string startYear = StartYear();
            string currentYear = CurrentYear();

            if (startYear == currentYear)
            {
                return ((AssemblyCopyrightAttribute)attributes[0]).Copyright;
            }
            else
            {
                string temp = ((AssemblyCopyrightAttribute)attributes[0]).Copyright;
                string start = temp.Remove(temp.IndexOf(startYear) - 1);
                string end = (temp.Remove(0, temp.IndexOf(" by")));

                return String.Concat(start, " ", startYear, "-", currentYear, end);
            }
        }
        #endregion

        #region DLL-Info
        /// <summary>
        /// Contains the name of the dll file.
        /// </summary>
        public static string DllName { private set; get; }

        /// <summary>
        /// Contains the version of the dll file.
        /// </summary>
        public static string DllVersion { private set; get; }

        /// <summary>
        /// Contains the copyright notice.
        /// </summary>
        public static string Copyright { private set; get; }

        /// <summary>
        /// Contains the name-, version- and copyright-information of the dll file.
        /// </summary>
        public static string[] DllInfo { private set; get; }

        private static void SetDllInfo()
        {
            //Name, Version und Copyright setzen
            DllName = dllName;
            DllVersion = dllVersion;
            Copyright = copyright;

            string[] dllInfo = new string[3];
            dllInfo[0] = dllName;
            dllInfo[1] = dllVersion;
            dllInfo[2] = copyright;
            DllInfo = dllInfo;
        }

        protected string ProgramName { private set; get; }
        protected string ProgramVersion { private set; get; }
        protected string ProgramCopyright { private set; get; }
        #endregion

        public enum RegMainKey
        {
            ClassesRoot,
            CurrentUser,
            LocalMachine,
            Users,
            CurrentConfig
        }

        static Registry()
        {
            SetDllInfo();
        }

        public Registry()
        {
            SetDllInfo();
        }

        // Create a Subkey
        public RegMainKey MainKey { get; set; }
        public string SubKey { get; set; }
        public string Key { get; set; }
        public string Value { get; set; }
        public bool Error { get; set; }

        /// <summary>
        /// Write Values to the Subkey
        /// </summary>
        public void WriteSubkey()
        {
            // Write Values to the Subkey
            Microsoft.Win32.RegistryKey mKey = null;
            switch (MainKey)
            {
                case RegMainKey.ClassesRoot:
                    mKey = Microsoft.Win32.Registry.ClassesRoot;
                    break;
                case RegMainKey.CurrentUser:
                    mKey = Microsoft.Win32.Registry.CurrentUser;
                    break;
                case RegMainKey.LocalMachine:
                    mKey = Microsoft.Win32.Registry.LocalMachine;
                    break;
                case RegMainKey.Users:
                    mKey = Microsoft.Win32.Registry.Users;
                    break;
                case RegMainKey.CurrentConfig:
                    mKey = Microsoft.Win32.Registry.CurrentConfig;
                    break;
                default:
                    break;
            }

            RegistryKey newKey = mKey.CreateSubKey(SubKey);
            newKey.SetValue(Key, Value);
        }

        /// <summary>
        /// Read Values from the Subkey
        /// </summary>
        /// <returns></returns>
        /// <exception cref="Exception">Subkey does not exist exception</exception>
        public string ReadSubkey()
        {
            // Read Values from the Subkey
            Microsoft.Win32.RegistryKey mKey = null;
            switch (MainKey)
            {
                case RegMainKey.ClassesRoot:
                    mKey = Microsoft.Win32.Registry.ClassesRoot;
                    break;
                case RegMainKey.CurrentUser:
                    mKey = Microsoft.Win32.Registry.CurrentUser;
                    break;
                case RegMainKey.LocalMachine:
                    mKey = Microsoft.Win32.Registry.LocalMachine;
                    break;
                case RegMainKey.Users:
                    mKey = Microsoft.Win32.Registry.Users;
                    break;
                case RegMainKey.CurrentConfig:
                    mKey = Microsoft.Win32.Registry.CurrentConfig;
                    break;
                default:
                    break;
            }

            if (SubKeyExist(SubKey))
            {
                RegistryKey myKey = mKey.OpenSubKey(SubKey);
                return (string)myKey.GetValue(Key);
            }
            else
            {
                throw new Exception("Subkey does not exist!");
            }
        }

        /// <summary>
        /// Delete the Subkey
        /// </summary>
        /// <exception cref="Exception">Subkey to be deleted</exception>
        public void DeleteSubkey()
        {
            // Delete the Subkey
            Microsoft.Win32.RegistryKey mKey = null;
            switch (MainKey)
            {
                case RegMainKey.ClassesRoot:
                    mKey = Microsoft.Win32.Registry.ClassesRoot;
                    break;
                case RegMainKey.CurrentUser:
                    mKey = Microsoft.Win32.Registry.CurrentUser;
                    break;
                case RegMainKey.LocalMachine:
                    mKey = Microsoft.Win32.Registry.LocalMachine;
                    break;
                case RegMainKey.Users:
                    mKey = Microsoft.Win32.Registry.Users;
                    break;
                case RegMainKey.CurrentConfig:
                    mKey = Microsoft.Win32.Registry.CurrentConfig;
                    break;
                default:
                    break;
            }

            //string MyKey = SubKey.Remove(SubKey.LastIndexOf('\\'));

            if (SubKeyExist(SubKey))
            {
                mKey.DeleteSubKeyTree(SubKey);
            }
            else
            {
                throw new Exception("Subkey does not exist!");
            }
        }

        /// <summary>
        /// Check if a Subkey exist
        /// </summary>
        /// <param name="Subkey">Subkey to be queried</param>
        /// <returns></returns>
        public bool SubKeyExist(string Subkey)
        {
            // Check if a Subkey exist
            Microsoft.Win32.RegistryKey mKey = null;
            switch (MainKey)
            {
                case RegMainKey.ClassesRoot:
                    mKey = Microsoft.Win32.Registry.ClassesRoot;
                    break;
                case RegMainKey.CurrentUser:
                    mKey = Microsoft.Win32.Registry.CurrentUser;
                    break;
                case RegMainKey.LocalMachine:
                    mKey = Microsoft.Win32.Registry.LocalMachine;
                    break;
                case RegMainKey.Users:
                    mKey = Microsoft.Win32.Registry.Users;
                    break;
                case RegMainKey.CurrentConfig:
                    mKey = Microsoft.Win32.Registry.CurrentConfig;
                    break;
                default:
                    break;
            }
            RegistryKey myKey = mKey.OpenSubKey(Subkey);

            if (myKey == null)
            {
                return false;
            }
            else
            {
                return true;
            }
        }
    }
}