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

namespace Eugen.ESystem.Text
{
    public class FormattingLongStrings
    {
        #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 FormattingLongStrings()
        {
            SetDllInfo();
        }

        //public FormattingLongStrings()
        //{
        //    SetDllInfo();
        //}

        /// <summary>
        /// Defines the length type
        /// </summary>
        public enum LengthType
        {
            LineLength,
            IndentLength
        }

        /// <summary>
        /// Splits a longer text into sections with a defined maximum length for each section
        /// </summary>
        /// <param name="text">Text to be edited</param>
        /// <param name="lengthFirstLine">Length of the first line in characters</param>
        /// <param name="lengthSubsequentLines">Length of the following line or the indentation in characters</param>
        /// <param name="lengthType">Defines whether the line length or the indentation is measured</param>
        /// <returns>Returns a string array with individual lines</returns>
        public static string[] FormattingString(string text, int lengthFirstLine, int lengthSubsequentLines, LengthType lengthType)
        {
            // If the text line is longer than the desired first line length, then split it, otherwise it is already ok
            if (text.Length > lengthFirstLine)
            {
                lengthSubsequentLines = LengthSubsequentLines(lengthFirstLine, lengthSubsequentLines, lengthType); // The text length of the other lines is calculated
                int indentLength = lengthFirstLine - lengthSubsequentLines; ;

                List<string> lines = new List<string>();

                lines.Add(CreateLine(text, lengthFirstLine)); // Create the first line in the length of the first line

                text = ShortenStringByAlreadyUsed(text, lines[0]); // The text already used is removed from the text

                text = RemoveLeadingSpaces(text); // If the text line begins with a space, remove it

                string tempText = "";

                // If the text line is longer than the desired line length, then split it
                while (text.Length > lengthSubsequentLines)
                {
                    tempText = CreateLine(text, lengthSubsequentLines);

                    // Generate the other lines with the corresponding length
                    if (lengthType == LengthType.LineLength)
                    {
                        lines.Add(tempText); // If the line length of the additional lines
                    }
                    else
                    {
                        // Line length is the length of the first line minus the length of the indentation
                        // Spaces in the number of indents are placed in front of the text
                        lines.Add(tempText.PadLeft(indentLength + tempText.Length, ' '));
                    }

                    text = ShortenStringByAlreadyUsed(text, tempText); // The text already used is removed from the text

                    text = RemoveLeadingSpaces(text); // If the text line begins with a space, remove it
                }

                // If the text still contains characters, then edit
                if (text.Length > 0)
                {
                    if (lengthType == LengthType.LineLength)
                    {
                        lines.Add(text); // If the line type is 'Line length' then add
                    }
                    else
                    {
                        lines.Add(text.PadLeft(indentLength + text.Length, ' ')); // Otherwise, precede with a space and then add
                    }
                }

                return lines.ToArray();
            }
            else
            {
                string[] value = {text}; // If the text is shorter than the line length, then use it
                return value;
            }
        }

        private static int LengthSubsequentLines(int lengthFirstLine, int lengthSubsequentLines, LengthType lengthType)
        {
            // Returns the length of the subsequent lines, depending on the line type
            if (lengthType == LengthType.LineLength)
            {
                return lengthSubsequentLines; // Line length
            }
            else
            {
                return lengthFirstLine - lengthSubsequentLines; // Line length with indentation
            }
        }

        private static string CreateLine(string text, int lineLength)
        {
            // Returns a text section of the specified length
            string tempLine = text.Remove(lineLength);
            string tempRemainingLine = text.Remove(0, lineLength);

            // If the next part begins with a space, the line ends with a whole word
            if (tempRemainingLine.StartsWith(" "))
            {
                return tempLine; // Then use the line as it is
            }
            else
            {
                return tempLine.Remove(tempLine.LastIndexOf(" ")); // Otherwise shorten the line up to the last space
            }
        }

        private static string ShortenStringByAlreadyUsed(string text, string usedCharacters)
        {
            // Remove the piece of text used from the entire text
            return text.Replace(usedCharacters, "");
        }

        private static string RemoveLeadingSpaces(string text)
        {
            // If the text line begins with a space, remove the space
            while (text.StartsWith(" "))
            {
                text = text.Remove(0, 1);
            }

            return text;
        }
    }
}