using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using Eugen.ESystem.IO;

namespace Eugen.NX
{
    public class NxLogfile
    {
        #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

        /// <summary>
        /// Sets the DLL information
        /// </summary>
        static NxLogfile()
        {
            SetDllInfo();
        }

        /// <summary>
        /// Reads out all NX log files stored in the specified directory
        /// </summary>
        /// <param name="nxLogFilePath">Directory in which the NX log files are stored</param>
        public NxLogfile(string nxLogFilePath)
        {
            SetDllInfo();
            LogFileExtension = "syslog";
            NxLogFilePath = nxLogFilePath;
            NxLogFiles = ReadNxLogfiles(NxLogFilePath, LogFileExtension);
            CurrentNxLogFile = NxLogFiles[0];
            LastNxLogFile = NxLogFiles[1];
        }

        private string NxLogFilePath { set; get; } //Verzeichnis in dem die NX-Logdateien gespeichert sind

        /// <summary>
        /// All NX log files stored in 'NxLogFilePath' (sorted)
        /// </summary>
        public string[] NxLogFiles { private set; get; } //Alle in 'NxLogFilePath' gespeicherten NX-Logdateien (sortiert)

        /// <summary>
        /// The current NX log file
        /// </summary>
        public string CurrentNxLogFile { private set; get; } //Die aktuelle NX-Logdatei

        /// <summary>
        /// The last NX log file
        /// </summary>
        public string LastNxLogFile { private set; get; } //Die letzte (aus der vorigen Sitzung) NX-Logdatei
        private string LogFileExtension { set; get; } //Dateiendung einer NX-Logdatei

        /// <summary>
        /// Shows the specified log file
        /// </summary>
        /// <param name="fileName">The log file to display</param>
        /// <exception cref="FileNotFoundException"></exception>
        public void ShowNxLogFile(string fileName)
        {
            if (File.Exists(fileName))
            {
                ShowTextFile.Show(fileName);
            }
            else
            {
                throw new FileNotFoundException();
            }
        }

        /// <summary>
        /// Writes the log file to a string
        /// </summary>
        /// <param name="fileName">The log file to write</param>
        /// <returns>A string</returns>
        /// <exception cref="FileNotFoundException">If the log file was not found</exception>
        public string GetNxLogFileAsString(string fileName)
        {
            try
            {
                return File.ReadAllText(fileName);
            }
            catch (Exception)
            {
                throw new FileNotFoundException();
            }
        }

        private string[] ReadNxLogfiles(string path, string logFileExtension)
        {
            List<Logfile> logfiles = new List<Logfile>();

            try
            {
                foreach (string file in Directory.GetFiles(path))
                {
                    if (file.EndsWith(logFileExtension))
                    {
                        FileInfo f1 = new FileInfo(file);
                        logfiles.Add(new Logfile { FileName = file, CreationTime = f1.CreationTime.ToString() });
                    }
                }
            }
            catch (Exception)
            {
                throw new FileNotFoundException();
            }

            var sortedLogfiles = logfiles.OrderBy(o => o.CreationTime).ToList();
            sortedLogfiles.Reverse();

            string[] logFileList = new string[sortedLogfiles.Count];

            int x = 0;

            foreach (var file in sortedLogfiles)
            {
                logFileList[x] = file.FileName;
                x++;
            }

            return logFileList;
        }
    }

    class Logfile
    {
        public string FileName { get; set; }
        public string CreationTime { get; set; }
    }
}