using System;



namespace SharpMud.Net.Telnet.ANSI

{

	public class Utility

	{		

		protected Utility()

		{

		}



        static Utility()

        {

            InitializeColorLookup();

        }



        internal const int ForegroundDefaultColor = 39;

        internal const int BackgroundDefaultColor = 49;

        internal const int BackgroundForegroundDifference = BackgroundDefaultColor - ForegroundDefaultColor;



		/// <summary>

		/// This property returns a string for the regular expression that will match ANSI

		/// control sequences with 99% accuracy.

		/// </summary>

		public static string AnsiSequenceRegex

		{

			get

			{

				return System.Text.RegularExpressions.Regex.Escape(ESC) + @"\[{0,1}\d*[;\d]*[a-zA-Z]";

			}

		}



		/// <summary>

		/// Returns the ANSI escape sequence that will move the cursor UP the

		/// given number of lines

		/// </summary>

		/// <param name="numLines">The number of lines to move the cursor</param>

		/// <returns>Returns an ANSI escape sequence</returns>

		public static string MoveCursorUp(int numLines)

		{

			return ESC + String.Format("[{0}A",numLines);

		}



		/// <summary>

		/// Returns the ANSI escape sequence that will move the cursor DOWN the

		/// given number of lines

		/// </summary>

		/// <param name="numLines">The number of lines to move the cursor</param>

		/// <returns>Returns an ANSI escape sequence</returns>

		public static string MoveCursorDown(int numLines)

		{

			return ESC + String.Format("[{0}B",numLines);

		}



		/// <summary>

		/// Returns the ANSI escape sequence that will move the cursor RIGHT the

		/// given number of columns

		/// </summary>

		/// <param name="numCols">The number of columns to move the cursor</param>

		/// <returns>Returns an ANSI escape sequence</returns>

		public static string MoveCursorRight(int numCols)

		{

			return ESC + String.Format("[{0}C",numCols);

		}



		/// <summary>

		/// Returns the ANSI escape sequence that will move the cursor LEFT the

		/// given number of columns

		/// </summary>

		/// <param name="numCols">The number of columns to move the cursor</param>

		/// <returns>Returns an ANSI escape sequence</returns>

		public static string MoveCursorLeft(int numCols)

		{

			return ESC + String.Format("[{0}D",numCols);

		}



		/// <summary>

		/// Returns the ANSI sequence that instructs the terminal to save the

		/// current cursor position

		/// </summary>

		public static string SaveCursorPosition

		{

			get

			{

				return ESC + "[s";

			}

		}



		/// <summary>

		/// Returns the ANSI sequence that instructs the terminal to resume the

		/// cursor position to the last saved one

		/// </summary>

		public static string LoadCursorPosition

		{

			get

			{

				return ESC + "[u";

			}

		}



		/// <summary>

		/// Returns the ANSI sequence that clears the screen and moves the cursor

		/// to the beginning of the line

		/// </summary>

		public static string ClearScreenAndHomeCursor

		{

			get

			{

				return ESC + "[2J";

			}

		}



		/// <summary>

		/// Returns the ANSI sequence that clears to the end of the current line

		/// </summary>

		public static string ClearToEOL

		{

			get

			{

				return ESC + "K";

			}

		}



        public static string SetColor(ForegroundColor foregroundColor)

        {

            string seq=null;

            bool found=false;

            found = _ForegroundLookupTable.TryGetValue(foregroundColor, out seq);

            if (!found)

                return null;

            if (found)

                return seq;

            return null;

        }



        public static string SetColor(BackgroundColor backgroundColor)

        {

            string seq = null;

            bool found = false;

            found = _BackgroundLookupTable.TryGetValue(backgroundColor, out seq);

            if (!found)

                return null;

            if (found)

                return seq;

            return null;

        }



		public static string SetForegroundColor(BasicColor foregroundColor)

		{

			return ESC + String.Format("[{0}m",

				(int)MakeScopedColor(foregroundColor,TextColorScope.FG) );

		}



		public static string SetBackgroundColor(BasicColor backgroundColor)

		{

			return ESC + String.Format("[{0}m",

				(int)MakeScopedColor(backgroundColor,TextColorScope.BG) );

		}



        public static string SetForegroundColorDefault()

        {

            return ESC + String.Format("[{0},", (int)Utility.ForegroundDefaultColor);

        }



        public static string SetBackgroundColorDefault()

        {

            return ESC + String.Format("[{0},", (int)Utility.BackgroundDefaultColor);

        }



		/// <summary>

		/// Returns an ANSI sequence that operates the given attribute, a 

		/// foreground color, and a background color, on the terminal

		/// </summary>

		/// <param name="attribute">An extended text attribute to use</param>

		/// <param name="foregroundColor">The foreground color to use</param>

		/// <param name="backgroundColor">The background color to use</param>

		/// <returns>Returns an ANSI escape sequence</returns>

        public static string SetTextAttributes(ExtendedTextAttribute attribute, BasicColor foregroundColor, BasicColor backgroundColor)

		{

			return ESC + String.Format("[{0};{1};{2}m",

				(int)attribute,

				(int)MakeScopedColor(foregroundColor,TextColorScope.FG),

				(int)MakeScopedColor(backgroundColor,TextColorScope.BG));

		}



        public static string SetTextColor(BasicColor basicAnsiColor, ColorScope colorScope)

        {

            return SetTextColor(basicAnsiColor, colorScope, false);

        }



        public static string SetTextColor(BasicColor basicAnsiColor, ColorScope colorScope, bool useBright)

        {

            if (colorScope == ColorScope.Background && useBright == true)

            {

                throw new ArgumentException("You cannot combine the 'bright' attribute with a background color.");

            }

            if (!System.Enum.IsDefined(typeof(ColorScope), colorScope))

                throw new ArgumentException("Argument value undefined.", "colorScope");

            if (!System.Enum.IsDefined(typeof(BasicColor), basicAnsiColor))

                throw new ArgumentException("Argument value undefined.", "basicAnsiColor");



            int resultAnsiColor;

            if (colorScope == ColorScope.Foreground)

                resultAnsiColor = (int)basicAnsiColor;

            else

                resultAnsiColor = (int)basicAnsiColor + Utility.BackgroundForegroundDifference;



            if (!useBright)

                return ESC + String.Format("[{0};{1}m", (int)ExtendedTextAttribute.Normal,resultAnsiColor);

            if (useBright)

                return ESC + String.Format("[{0};{1}m", (int)ExtendedTextAttribute.Bold, resultAnsiColor);



            return null;

        }



		/// <summary>

		/// Returns an ANSI sequence that operates the given ANSI attribute on a terminal

		/// </summary>

		/// <param name="attribute">An extended text attribute to use</param>

		/// <returns>Returns an ANSI escape sequence</returns>

		public static string SetTextAttributes(ExtendedTextAttribute attribute)

		{

			return ESC + String.Format("[{0}m",

				(int)attribute );

		}



		/// <summary>

		/// Returns an ANSI sequence that operates the given

		/// foreground color and background color on the terminal

		/// </summary>

		/// <param name="foregroundColor">The foreground color to use</param>

		/// <param name="backgroundColor">The background color to use</param>

		/// <returns>Returns an ANSI escape sequence</returns>

		public static string SetTextAttributes(BasicColor foregroundColor, BasicColor backgroundColor)

		{

			return ESC + String.Format("[{0};{1}m",

				(int)MakeScopedColor(foregroundColor,TextColorScope.FG),

				(int)MakeScopedColor(backgroundColor,TextColorScope.BG));

		}



		/// <summary>

		/// Returns the ANSI escape sequence that will move the cursor to another

		/// onscreen location

		/// </summary>

		/// <param name="line">The line number to move the cursor to</param>

		/// <param name="col">The column number to move the cursor to</param>

		/// <returns>Returns an ANSI escape sequence</returns>

		public static string MoveCursorTo(int line, int col)

		{

			return ESC + String.Format("[{0};{1}H",line,col);

		}



		

		/// <summary>

		/// The magic string (character) that must begin all ANSI control sequences

		/// </summary>

		public const string ESC = "\x1B"; // ASCII # 33



		/// <summary>

		/// Whether or not a color is for the foreground or background

		/// </summary>

		internal enum TextColorScope

		{

			Foreground = ColorScope.Foreground,

			Background = ColorScope.Background,

			FG = Foreground,

			BG = Background

		}



		/// <summary>

		/// This method takes a basic color and translates it to the form that can be inserted

		/// into an ANSI sequence, by taking into account whether or not it is a foreground or

		/// background color.

		/// </summary>

		/// <param name="color">The basic color to translate</param>

		/// <param name="scope">Whether or not the color is for foreground or background</param>

		/// <returns>Returns a scoped color</returns>

		internal static ScopedColor MakeScopedColor(BasicColor color, TextColorScope scope)

		{

			if(scope==TextColorScope.Foreground)

			{

				return (ScopedColor)color;

			}

			else if(scope==TextColorScope.Background)

			{

				return (ScopedColor)(color+10);

			}

			else

			{

				throw new ArgumentOutOfRangeException("scope");

			}

        }



        #region Color Value Lookup

        private static System.Collections.Generic.Dictionary<ForegroundColor, string> _ForegroundLookupTable;

        private static System.Collections.Generic.Dictionary<BackgroundColor, string> _BackgroundLookupTable;



        /// <summary>

        /// Since ANSI sequences for enum-based color values are stored using custom attributes,

        /// and reflection isn't the fastest way to lookup data, we need to pre-fetch the data

        /// </summary>

        private static void InitializeColorLookup()

        {

            _ForegroundLookupTable = new System.Collections.Generic.Dictionary<ForegroundColor, string>();

            _BackgroundLookupTable = new System.Collections.Generic.Dictionary<BackgroundColor, string>();



            string s = null;

            AnsiRepresentationAttribute ara = null;



            ///Program in ForegroundColor lookups

            foreach (ForegroundColor colorValue in System.Enum.GetValues(typeof(ForegroundColor)))

            {

                s = null;

                ara = null;



                ara = AnsiRepresentationAttribute.FindForValue<ForegroundColor>(colorValue);

                if (ara != null)

                {

                    if (_ForegroundLookupTable.ContainsKey(colorValue) == false)

                    {

                        s = ara.Sequence;

                        _ForegroundLookupTable.Add(colorValue, s);

                    }

                }

            }



            ///Program in BackgroundColor lookups

            foreach (BackgroundColor colorValue in System.Enum.GetValues(typeof(BackgroundColor)))

            {

                s = null;

                ara = null;



                ara = AnsiRepresentationAttribute.FindForValue<BackgroundColor>(colorValue);

                if (ara != null)

                {

                    if (_BackgroundLookupTable.ContainsKey(colorValue) == false)

                    {

                        s = ara.Sequence;

                        _BackgroundLookupTable.Add(colorValue, s);

                    }

                }

            }

        }

        

        #endregion

    }

}