using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Security.Permissions;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using static System.Net.Mime.MediaTypeNames;

namespace Eugen.ESystem
{
    public class Roaming
    {
        #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

        static Roaming()
        {
            SetDllInfo();
        }

        public Roaming()
        {
            SetDllInfo();
            RoamingPath = GetAppData();
        }

        enum Option
        {
            Write,
            Read
        }

        /// <summary>
        /// The roaming folder
        /// </summary>
        public string RoamingPath { private set; get; } //Pfad zum Roaming-Verzeichnis

        /// <summary>
        /// The main key(folder)
        /// </summary>
        public string MainKey { get; set; } //Hauptschlüssel oder Hauptordner

        /// <summary>
        /// The sub key(folder), located under the main key
        /// </summary>
        public string SubKey { get; set; } //Unterschlüssel oder Unterordner

        /// <summary>
        /// The key contains the value
        /// </summary>
        public string Key { get; set; } //Schlüssel

        /// <summary>
        /// The value
        /// </summary>
        public string Value { get; set; } //Wert

        /// <summary>
        /// Writes the key
        /// </summary>
        /// <exception cref="UnableToCreateRoamingEntryException">If the key could not be written</exception>
        public void WriteKey()
        {
            string x = GenerateKey(Option.Write);
            try
            {
                File.WriteAllText(GenerateKey(Option.Write), Value);
            }
            catch (Exception)
            {
                throw new UnableToCreateRoamingEntryException();
            }
        }

        /// <summary>
        /// Reads the key
        /// </summary>
        /// <returns></returns>
        /// <exception cref="UnableToReadRoamingEntryException">If the key could not be read</exception>
        public string ReadKey()
        {
            try
            {
                File.ReadAllText(GenerateKey(Option.Read));
            }
            catch (Exception)
            {
                throw new UnableToReadRoamingEntryException();
            }
            return Value;
        }

        /// <summary>
        /// Deletes the key
        /// </summary>
        /// <exception cref="UnableToDeleteRoamingEntryException">If the key could not be deleted</exception>
        public void DeleteKey()
        {
            try
            {
                if (File.Exists(GenerateKey(Option.Read)))
                {
                    File.Delete(GenerateKey(Option.Read));
                }
            }
            catch (Exception)
            {
                throw new UnableToDeleteRoamingEntryException();
            }
        }

        /// <summary>
        /// Deletes the subkey including its content
        /// </summary>
        /// <exception cref="UnableToDeleteRoamingEntryException">If the subkey could not be deleted</exception>
        public void DeleteSubKey()
        {
            try
            {
                if (!String.IsNullOrEmpty(SubKey))
                {
                    if (Directory.Exists(RoamingPath + "\\" + MainKey + "\\" + SubKey))
                    {
                        Directory.Delete(RoamingPath + "\\" + MainKey + "\\" + SubKey, true);
                    }
                }
            }
            catch (Exception)
            {
                throw new UnableToDeleteRoamingEntryException();
            }
        }

        /// <summary>
        /// Deletes the maikey including its content
        /// </summary>
        /// <exception cref="UnableToDeleteRoamingEntryException">If the mainkey could not be deleted</exception>
        public void DeleteMainKey()
        {
            try
            {
                if (Directory.Exists(RoamingPath + "\\" + MainKey))
                {
                    Directory.Delete(RoamingPath + "\\" + MainKey, true);
                }
            }
            catch (Exception)
            {
                throw new UnableToDeleteRoamingEntryException();
            }
        }

        /// <summary>
        /// Checks whether the roaming path exists
        /// </summary>
        /// <returns>'True' if the roaming path exists, otherwise 'false'</returns>
        public bool RoamingPathExists()
        {
            return Directory.Exists(RoamingPath);
        }

        /// <summary>
        /// Checks whether the main key exists
        /// </summary>
        /// <returns>'True' if the main key exists, otherwise 'false'</returns>
        public bool MainKeyExists()
        {
            return Directory.Exists(RoamingPath + "\\" + MainKey);
        }

        /// <summary>
        /// Checks whether the sub key exists
        /// </summary>
        /// <returns>'True' if the sub key exists, otherwise 'false'</returns>
        public bool SubKeyExists()
        {
            return Directory.Exists(RoamingPath + "\\" + MainKey + "\\" + SubKey);
        }

        /// <summary>
        /// Checks whether the key exists
        /// </summary>
        /// <returns>'True' if the key exists, otherwise 'false'</returns>
        public bool KeyExists()
        {
            if (SubKeyExists())
            {
                return Directory.Exists(RoamingPath + "\\" + MainKey + "\\" + SubKey + "\\" + Key);
            }
            else
            {
                return Directory.Exists(RoamingPath + "\\" + MainKey + "\\" + Key);
            }
        }

        /// <summary>
        /// Checks whether the key is 'null' or 'empty'
        /// </summary>
        /// <returns>'True' if the key is 'null' or 'empty', otherwise 'false'</returns>
        public bool ValueIsNullOrEmpty()
        {
            if (KeyExists())
            {
                if (String.IsNullOrEmpty(ReadKey()))
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            else
            {
                return true;
            }
        }

        private string GetAppData()
        {
            return Environment.GetEnvironmentVariable("APPDATA"); //Ermittelt den Pafad des Verzeichnisses '%APPDATA%\Roaming'
        }

        private string GenerateKey(Option option)
        {
            string key = "";

            try
            {
                if (!Directory.Exists(RoamingPath + "\\" + MainKey))
                {
                    if (option == Option.Write)
                    {
                        Directory.CreateDirectory(RoamingPath + "\\" + MainKey);
                    }
                    else
                    {
                        throw new UnableToReadRoamingEntryException();
                    }
                }

                if (String.IsNullOrEmpty(SubKey))
                {
                    SubKey = "";
                }
                else
                {
                    if (option == Option.Write)
                    {
                        if (!Directory.Exists(RoamingPath + "\\" + MainKey + "\\" + SubKey))
                        {
                            Directory.CreateDirectory(RoamingPath + "\\" + MainKey + "\\" + SubKey);
                        }
                    }
                }
                
                if (SubKey == "")
                {
                    key = RoamingPath + "\\" + MainKey + "\\" + Key;
                }
                else
                {
                    key = RoamingPath + "\\" + MainKey + "\\" + SubKey + "\\" + Key;
                }
            }
            catch (Exception)
            {
                throw new UnableToGenerateKeyException();
            }

            return key;
        }
    }

    #region Exceptions
    class UnableToCreateRoamingEntryException : ApplicationException
    {
        public UnableToCreateRoamingEntryException()
        { }

        public UnableToCreateRoamingEntryException(string message) : base(message)
        { }

        public UnableToCreateRoamingEntryException(string message, Exception inner) : base(message, inner)
        { }
    }


    class UnableToReadRoamingEntryException : ApplicationException
    {
        public UnableToReadRoamingEntryException()
        { }

        public UnableToReadRoamingEntryException(string message) : base(message)
        { }

        public UnableToReadRoamingEntryException(string message, Exception inner) : base(message, inner)
        { }
    }


    class UnableToDeleteRoamingEntryException : ApplicationException
    {
        public UnableToDeleteRoamingEntryException()
        { }

        public UnableToDeleteRoamingEntryException(string message) : base(message)
        { }

        public UnableToDeleteRoamingEntryException(string message, Exception inner) : base(message, inner)
        { }
    }


    class UnableToGenerateKeyException : ApplicationException
    {
        public UnableToGenerateKeyException()
        { }

        public UnableToGenerateKeyException(string message) : base(message)
        { }

        public UnableToGenerateKeyException(string message, Exception inner) : base(message, inner)
        { }
    }
    #endregion
}