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

// The general idea of this program is to look through a folder with XML-files
// and delete nodes that match certain content.
// A configuration file will tell what nodes to delete if any of the
// content specified in the file is found either as element or attribute in
// the node or one of it's children.

namespace RemoveSpam
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("\r\n" + "\r\n" + "RemoveSpam by ReSQueL" + "\r\n");
            Console.WriteLine("Intended to remove *back spam from dasBlog." + "\r\n");
            if (args.Length != 2)
            {
                Console.WriteLine("This program takes two arguments.");
                Console.WriteLine("  1st the location of the config file.");
                Console.WriteLine("  2nd the location of the target folder.");
                Console.WriteLine("Use double quotes (\") to deal with spaces in the paths.");
                Console.WriteLine("");
                Console.WriteLine("example:");
                Console.WriteLine("RemoveSpam \"C:\\My Config Folder\\RemoveSpam.xml\" \\\\MyServer\\MyShare\\TargetFolder");
                Console.WriteLine("");
                Console.WriteLine("To create a sample config file (includes documentation), use /config;");
                Console.WriteLine("RemoveSpam \"C:\\My Config Folder\\RemoveSpam.xml\" /config");
                Console.ReadKey();
            }
            else
            {
                string arg0 = args[0].ToString();
                string arg1 = args[1].ToString();
                if (arg1 == "/config")
                {
                    MakeConfig(arg0);
                }
                else
                {
                    ProcessFolder(arg0, arg1);
                }
            }
        }

        static void MakeConfig(string ConfigFile)
        {
            XmlDocument objConfigFile = new XmlDocument();
            objConfigFile.LoadXml(
                "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\r\n" +
                "<RemoveSpam>\r\n" +
                "  <Documentation>\r\n" +
                "    RemoveSpam was built after a massive attack of trackback and pingback spam\r\n" +
                "    on a blog running dasBlog. While this is not a durable solution against\r\n" +
                "    *back-spam, it may help you clean up the *backs.\r\n" +
                "    The spam is found based on a simple pattern-match against all XML documents\r\n" +
                "    in a given folder (the content folder of dasBlog). It matches the PermaLink\r\n" +
                "    elements within DayExtra, Trackings, Tracking. If a match is found, the\r\n" +
                "    entire Tracking element is deleted.\r\n" +
                "    <br/>\r\n" +
                "    To see some examples of patterns, see Configs element. Each pattern has a Config\r\n" +
                "    element, with the Pattern attribute that shows what pattern is a spamvertised\r\n" +
                "    PermaLink. Pattern is build with the characters from the URL and takes wildcards\r\n" +
                "    \"*\" (star) and \"^\" (caret).\r\n" +
                "    * = 0 or more characters.\r\n" +
                "    ^ = 1 character.\r\n" +
                "    For those wondering, the question mark can not be used as a single poition wildcard,\r\n" +
                "    as it is meaningful and common in URLs.\r\n" +
                "    <br/>\r\n" +
                "    Edit or add Config elements to suit your needs.\r\n" +
                "  </Documentation>\r\n" +
                "  <Configs>\r\n" +
                "    <Config Pattern=\"*free-porn.info/*\"/>\r\n" +
                "    <Config Pattern=\"9^^-information.info/*.html\"/>\r\n" +
                "  </Configs>\r\n" +
                "  <About>\r\n" +
                "    <Author>Stan Segers</Author>\r\n" +
                "    <ReleaseDate>2007-06-07</ReleaseDate>\r\n" +
                "    <Web>http://www.resquel.com</Web>\r\n" +
                "    <Mailto>mailto://query@resquel.com</Mailto>\r\n" +
                "  </About>\r\n" +
                "</RemoveSpam>");
            try
            {
                objConfigFile.Save(ConfigFile);
                Console.WriteLine("Config file succesfully created.\r\n");
            }
            catch(Exception e)
            {
                Console.WriteLine(e.Message);
            }
        }

        static void ProcessFolder(string ConfigFile, string TargetFolder)
        {
            //Read the patterns, turn them into RegEx and put them in an ArrayList.
            ArrayList arrPattern = new ArrayList();
            XmlDocument objConfigFile = new XmlDocument();
            XmlNodeList objConfigDetails;
            try
            {
                objConfigFile.Load(ConfigFile);
                objConfigDetails = objConfigFile.SelectNodes("/RemoveSpam/Configs/Config");

                foreach (XmlNode objConfigDetail in objConfigDetails)
                {
                    // Convert the Pattern InnerText to a Regular Expression.
                    // Following rules apply in this order:
                    // 1. Escape all special characters. but not the caret and star
                    //    Special characters        [\^$.|?*+()
                    // 2. Replace all carets by dots.
                    // 3. Preceed all stars with a single dot.
                    string strConvert = objConfigDetail.Attributes["Pattern"].InnerText;
                    
                    Console.WriteLine("PermaLink pattern: " + strConvert); // Debug line
                    // Conversions 1
                    strConvert = strConvert.Replace("[", "\\[");
                    strConvert = strConvert.Replace("\\", "\\\\");
                    strConvert = strConvert.Replace("$", "\\$");
                    strConvert = strConvert.Replace(".", "\\.");
                    strConvert = strConvert.Replace("|", "\\|");
                    strConvert = strConvert.Replace("?", "\\?");
                    strConvert = strConvert.Replace("+", "\\+");
                    strConvert = strConvert.Replace("(", "\\(");
                    strConvert = strConvert.Replace(")", "\\)");
                    // Conversion 2
                    strConvert = strConvert.Replace("^", ".");
                    // Conversion 3
                    strConvert = strConvert.Replace("*", ".*");
                    //Add to ArrayList
                    arrPattern.Add(strConvert);
                };
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }

            // Process a folder and put all filenames in an array.
            DirectoryInfo objDir = new DirectoryInfo(TargetFolder);
            FileInfo[] objFile = objDir.GetFiles("*.xml");
            try
            {
                if (objFile.Length == 0)
                {
                    Console.WriteLine("No .xml files found in " + TargetFolder + "!");
                }
                else for (int i = 0; i < objFile.Length; i++)
                    {
                        ProcessFile(arrPattern, objFile[i].FullName);
                    }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }         
        }

        static void ProcessFile(ArrayList Pattern, string FileName)
        {
            string strNameSpace = "urn:newtelligence-com:dasblog:runtime:data";
            string strPrefix = "dasBlog";
            string strXPath = "/dasBlog:DayExtra/dasBlog:Trackings/dasBlog:Tracking/dasBlog:PermaLink";
            bool boolChanged = false;
            
            XmlDocument objContentFile = new XmlDocument();
            
            try
            {   
                Console.WriteLine("Processing file: " + FileName); // Debug line
                objContentFile.Load(FileName);

                XmlNamespaceManager objNsMgr = new XmlNamespaceManager(objContentFile.NameTable);
                objNsMgr.AddNamespace(strPrefix, strNameSpace);
                // Deal with the XMLNameSpace.
                XmlNodeList objContentDetails = objContentFile.SelectNodes(strXPath, objNsMgr);
                foreach (XmlNode objContentDetail in objContentDetails)
                {
                    string strConvert = objContentDetail.InnerText;
                    for (int i = 0; i < Pattern.Count; i++)
                    {
                        Regex objRegexPattern = new Regex(Pattern[i].ToString(), RegexOptions.IgnoreCase);
                        if (objRegexPattern.IsMatch(strConvert) == true)
                        {
                            try
                            {
                                Console.WriteLine("Match found: " + strConvert);
                                // objContentDetail.ParentNode.RemoveAll();
                                // Commented line above left an empty Tracking element in the document.
                                // Suspected to cause errors with the dasBlog trackbackList macro.
                                // Changed 2007-06-18
                                objContentDetail.ParentNode.ParentNode.RemoveChild(objContentDetail.ParentNode);
                                boolChanged = true;
                            }
                            catch (Exception e)
                            {
                                Console.WriteLine(e.Message);
                            }
                        }
                    }
                }
                // Write back the XML after cleaning.
                if (boolChanged == true)
                {
                    objContentFile.Save(FileName);
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
        }
    }
}