using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;

namespace Volian.Base.Library
{
	public class RtfTools
	{
		public static List<string> SplitText(string text, int len)
		{
			{
				List<string> results = new List<string>();
				if (text.Contains("\\LINE ") || text.Contains("\r\n"))
				{
					string[] mySplit = { "\\LINE ", "\r\n" };
					return new List<string>(text.Split(mySplit, StringSplitOptions.None));

				}
				int width = 0;			// width of text, non-rtf
				int start = 0;			// start of line (index into string 'text'), includes rtf
				int lastspace = 0;		// location of lastspace (index into string 'text'), includes rtf
				int startNonRtf = 0;	// start of line, non-rtf (used for determining starting position to determine width if there was a break)
				string rtfprefix = "";
				string nextprefix = "";
				for (int indx = 0; indx < text.Length; indx++)
				{
					if (text[indx] == '\\')   //rtf command
					{
						// look for three things at beginning of string: hex, unicode, rtfcommand.
						Match m = Regex.Match(text.Substring(indx), @"^\\'[a-fA-F0-9][a-fA-F0-9]");  //hex
						if (m.Success)
						{
							indx += m.Length - 1;
							width++;
						}
						else
						{
							m = Regex.Match(text.Substring(indx), @"^\\[uU][a-fA-F0-9][a-fA-F0-9][a-fA-F0-9][?]");  // 3 char unicode, for example \u160? (hardspace)
							if (m.Success)
							{
								indx += m.Length - 1;
								width++;
							}
							else
							{
								m = Regex.Match(text.Substring(indx), @"^\\[uU][a-fA-F0-9][a-fA-F0-9][a-fA-F0-9][a-fA-F0-9][?]");
								if (m.Success)
								{
									indx += m.Length - 1;
									width++;
								}
								else
								{
									m = Regex.Match(text.Substring(indx), @"^\\[^ ]*? ");
									if (m.Success)
									{
										indx += m.Length - 1;
										rtfprefix = AdjustRtfPrefix(rtfprefix, m.Value);
									}
								}
							}
						}

					}
					else
					{
						if (text[indx] == ' ')
						{
							lastspace = indx;
							startNonRtf = width;
						}
						width++;
						if (width > len)
						{
							// what should be done if lastspace == 0
							// cannot find space char to split on, so break the word
							// not ideal but PROMS was bombing otherwise - jsj 7/7/2014
							if (lastspace == 0)
							{
								lastspace = indx;
								startNonRtf = width - 1;
							}
							results.Add(nextprefix + text.Substring(start, lastspace - start).Trim(" ".ToCharArray()));
							nextprefix = rtfprefix;
							if (nextprefix != "") nextprefix += " ";
							start = lastspace + 1;
							width = (width - startNonRtf - 1) > 0 ? width - startNonRtf - 1 : 0;
							lastspace = 0;
						}
					}

				}
				if (width > 0 || start < text.Length) results.Add(nextprefix + text.Substring(start).Trim(" ".ToCharArray()));
				return results;
			}
		}
		private static string AdjustRtfPrefix(string rtfprefix, string rtfcommand)
		{
			if (rtfcommand.Contains(@"\ulnone") || rtfcommand.Contains(@"\ul0"))   // off
				rtfprefix = rtfprefix.Replace(@"\ul", "");
			else if (rtfcommand.Contains(@"\ul"))
				rtfprefix += @"\ul";
			if (rtfcommand.Contains(@"\up0") || rtfcommand.Contains(@"\dn0")) rtfprefix = rtfprefix.Replace(@"\up2", "").Replace(@"\dn2", "");
			else if (rtfcommand.Contains(@"\up")) rtfprefix += @"\up2";
			else if (rtfcommand.Contains(@"\dn")) rtfprefix += @"\dn2";
			if (rtfcommand.Contains(@"\b0"))
				rtfprefix = rtfprefix.Replace(@"\b", "");
			else if (rtfcommand.Contains(@"\b"))
				rtfprefix += @"\b";
			if (rtfcommand.Contains(@"\i0"))
				rtfprefix = rtfprefix.Replace(@"\i", "");
			else if (rtfcommand.Contains(@"\i"))
				rtfprefix += @"\i";
			return rtfprefix;
		}
	}
}