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

public static class ClipboardFusionHelper
    {
        public static string ProcessText(string text)
            {
                // takes a string of text (typically multiline text) and converts it to a BBCode list used on nearly all forums
                // it tries to be smart enough to identify either a ordered list, or unordered list, but
                // it only detects ordered lists if they start at the beginning (i.e., a, i, A, I, 0, or 1)
                // it also tries to account for cut'n'pasting lists out of MS Word

                char chrLineIndent = ' '; // default to spaces
                int intLineIndentSize = 2;
                string strListType = "list"; // default to an unordered list
                string strListCSS = "";
                string strOutput = text.Trim();

                // remove multiple white spaces characters and replace them with a single space
                strOutput = Regex.Replace(strOutput, @"[ \t]+", " ");
                
                // remove empty lines ($ doesn't seem to work very well)
                strOutput = Regex.Replace(strOutput, @"(?<linebreak>[\r\n]{1,2})+", "${linebreak}");
                
                // trim the start and end of each line (Regex $ doesn't seem to work very well)
                strOutput = Regex.Replace(strOutput, @"(?:^[ \t]*)|(?:[ \t]*(?<linebreak>[\r\n]{1,2}))", "${linebreak}", RegexOptions.Multiline);
                
                if (Regex.IsMatch(strOutput , @"^[aiAI01][^\w0-9]+"))
                    {
                        // it looks like we are dealing with some sort of ordered list
                        strListType = "ol";
                        
                        // lets work out what type of ordered list it is
                        switch (strOutput[0].ToString())
                            {
                                case "a": strListCSS = "lower-alpha"; break;
                                case "i": strListCSS = "lower-roman"; break;
                                case "A": strListCSS = "upper-alpha"; break;
                                case "I": strListCSS = "upper-roman"; break;
                                case "0": strListCSS = "decimal-leading-zero"; break;
                            }
                        strListCSS = strListCSS.Length > 0 ? "list-style-type:" + strListCSS + ";" : "";

                        // remove the list item indicators
                        strOutput = Regex.Replace(strOutput, @"^[a-zA-Z0-9]+[^\w0-9]+", "", RegexOptions.Multiline);
                    }

                else if (Regex.IsMatch(strOutput, @"^[^a-np-zA-NP-Z0-9]+[^\w0-9]+"))
                    {
                        // it looks like we have some sort of bulleted unordered list
                        // typical bullets include ?, o, ?, #, *, -, ->, =, ?, etc.
                        strListType = "ul";

                        // lets work out what type of unordered list it is
                        switch (strOutput[0].ToString().ToLower())
                            {
                                case "o": strListCSS = "circle"; break;
                                case "[": strListCSS = "square"; break;
                                case "?": strListCSS = "square"; break;
                            }
                        strListCSS = strListCSS.Length > 0 ? "list-style-type:" + strListCSS + ";" : "";

                        // remove the list item indicators
                        strOutput = Regex.Replace(strOutput, @"^[^a-np-zA-NP-Z0-9]+[^\w0-9]+", "", RegexOptions.Multiline);
                    }

                string strLineIndent = new string(chrLineIndent, intLineIndentSize);

                // replace line breaks with <li>s (Regex $ doesn't seem to work very well)
                strOutput = Regex.Replace(strOutput, @"(?<linebreak>[\r\n]{1,2})", "[/li]${linebreak}" + strLineIndent + "[li]");
                
                strOutput = String.Format(
                "[{0}{1}]\r\n{2}[li]{3}[/li]\r\n[/{0}]",
                strListType,
                (strListCSS.Length > 0 ? " style=\"" + strListCSS + "\"" : ""),
                strLineIndent,
                strOutput
                );

                return strOutput;
        }
    }