// wikiCode.java 
// -------------------------------------
// part of YACY
//
// (C) 2005, 2006 by Alexander Schier 
//                   Marc Nause, Franz Brausse
//
//
// last change: $LastChangedDate: $ by $LastChangedBy: $
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// Using this software in any meaning (reading, learning, copying, compiling,
// running) means that you agree that the Author(s) is (are) not responsible
// for cost, loss of data or any harm that may be caused directly or indirectly
// by usage of this softare or this documentation. The usage of this software
// is on your own risk. The installation and usage (starting/running) of this
// software may allow other people or application to access your computer and
// any attached devices and is highly dependent on the configuration of the
// software which must be done by the user of the software; the author(s) is
// (are) also not responsible for proper configuration and usage of the
// software, even if provoked by documentation provided together with
// the software.
//
// Any changes to this file according to the GPL as documented in the file
// gpl.txt aside this file in the shipment you received can be done to the
// lines that follows this copyright notice here, but changes must not be
// done inside the copyright notive above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.

// Contains contributions from Alexander Schier [AS]
// Franz Brausse [FB] and Marc Nause [MN]

package de.anomic.data;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;

import de.anomic.plasma.plasmaSwitchboard;
import de.anomic.server.serverCore;
import de.anomic.yacy.yacyCore;

/** This class provides methods to handle texts that have been posted in the yacyWiki or other
  * parts of YaCy that use this class, like the blog or the profile.
  */
public class wikiCode {
    private String numListLevel="";
    private String ListLevel="";
    private String defListLevel="";
    private plasmaSwitchboard sb;
    private boolean cellprocessing=false;       //needed for prevention of double-execution of replaceHTML
    private boolean defList = false;            //needed for definition lists
    private boolean escape = false;             //needed for escape
    private boolean escaped = false;            //needed for <pre> not getting in the way
    private boolean escapeSpan = false;         //needed for escape symbols [= and =] spanning over several lines
    private boolean newrowstart=false;          //needed for the first row not to be empty
    private boolean nolist = false;             //needed for handling of [= and <pre> in lists
    private boolean preformatted = false;       //needed for preformatted text
    private boolean preformattedSpan = false;   //needed for <pre> and </pre> spanning over several lines
    private boolean replacedHTML = false;       //indicates if method replaceHTML has been used with line already
    private boolean replacedCharacters = false; //indicates if method replaceCharachters has been used with line
    private boolean table = false;              //needed for tables, because they reach over several lines
    private int preindented = 0;                //needed for indented <pre>s
    private int escindented = 0;                //needed for indented [=s
    private int headlines = 0;                  //number of headlines in page
    private ArrayList dirElements = new ArrayList();    //list of headlines used to create diectory of page

    /** Constructor of the class wikiCode */
    public wikiCode(plasmaSwitchboard switchboard){
        sb=switchboard;
    }

    public String transform(String content){
        try {
            return transform(content.getBytes("UTF-8"), sb);
        } catch (UnsupportedEncodingException e) {
            return transform(content.getBytes(), sb);
        }
    }

    public String transform(byte[] content){
        return transform(content, sb);
    }

    public String transform(byte[] content, plasmaSwitchboard switchboard) {
        ByteArrayInputStream bais = new ByteArrayInputStream(content);
        try {
            BufferedReader br = new BufferedReader(new InputStreamReader(bais,
                    "UTF-8"));
            String line;
            StringBuffer out = new StringBuffer(content.length);
            try {
                while ((line = br.readLine()) != null) {
                    out.append(transformLine(line, switchboard)).append(
                            serverCore.crlfString);
                }
                return directory()+out.toString();
            } catch (UnsupportedEncodingException e1) {
                // can not happen
                return null;
            }
        } catch (IOException e) {
            return "internal error: " + e.getMessage();
        }
    }

    /** Replaces special characters from a string. Avoids XSS attacks and ensures correct display of
      * special characters in non UTF-8 capable browsers.
      * @param text a string that possibly contains HTML
      * @return the string with all special characters encoded
      */
      //[MN]
    public static String replaceHTML(String text) {
        text = replace(text, xmlentities);
        text = replace(text, htmlentities);
        return text;
    }

    /** Replaces special characters from a string. Ensures correct display of
      * special characters in non UTF-8 capable browsers.
      * @param text a string that possibly contains special characters
      * @return the string with all special characters encoded
      */
      //[MN]
    public static String replaceHTMLEntities(String text) {
        text = replace(text, htmlentities);
        return text;
    }

    /** Replaces special characters from a string. Avoids XSS attacks.
      * @param text a string that possibly contains HTML
      * @return the string without any HTML-tags that can be used for XSS
      */
      //[MN]
    public static String replaceXMLEntities(String text) {
        text = replace(text, xmlentities);
        return text;
    }

    /** Replaces characters in a string with other characters defined in an array.
      * @param text a string that possibly contains special characters
      * @param entities array that contains characters to be replaced and characters it will be replaced by
      * @return the string with all characters replaced by the corresponding character from array
      */
      //[FB], changes by [MN]
    public static String replace(String text, String[] entities) {
        if (text==null) { return null; }
        for (int x=0;x<=entities.length-1;x=x+2) {
            int p=0;
            while ((p=text.indexOf(entities[x],p))>=0) {
                text=text.substring(0,p)+entities[x+1]+text.substring(p+entities[x].length());
                p+=entities[x+1].length();
            }
        }
        return text;
    }

    //This array contains codes (see http://mindprod.com/jgloss/unicode.html for details) 
    //that will be replaced. To add new codes or patterns, just put them at the end
    //of the list. Codes or patterns in this list can not be escaped with [= or <pre>
    public static String[] xmlentities={
        // Ampersands _have_ to be replaced first. If they were replaced later,
        // other replaced characters containing ampersands would get messed up.
        "\u0026","&amp;",      //ampersand
        "\"","&quot;",         //quotation mark
        "\u003C","&lt;",       //less than
        "\u003E","&gt;",       //greater than
    };

    //This array contains codes (see http://mindprod.com/jgloss/unicode.html for details) and
    //patterns that will be replaced. To add new codes or patterns, just put them at the end
    //of the list. Codes or patterns in this list can not be escaped with [= or <pre>
    public static String[] htmlentities={
        "\u005E","&#094;",  // Caret

        "\u0060","&#096;",  // Accent Grave `
        "\u007B","&#123;",  // {
        "\u007C","&#124;",  // |
        "\u007D","&#125;",  // }
        "\u007E","&#126;",  // ~

        "\u0082","&#130;",
        "\u0083","&#131;",
        "\u0084","&#132;",
        "\u0085","&#133;",
        "\u0086","&#134;",
        "\u0087","&#135;",
        "\u0088","&#136;",
        "\u0089","&#137;",
        "\u008A","&#138;",
        "\u008B","&#139;",
        "\u008C","&#140;",
        "\u008D","&#141;",
        "\u008E","&#142;",

        "\u0091","&#145;",
        "\u0092","&#146;",
        "\u0093","&#147;",
        "\u0094","&#148;",
        "\u0095","&#149;",
        "\u0096","&#150;",
        "\u0097","&#151;",
        "\u0098","&#152;",
        "\u0099","&#153;",
        "\u009A","&#154;",
        "\u009B","&#155;",
        "\u009C","&#156;",
        "\u009D","&#157;",
        "\u009E","&#158;",
        "\u009F","&#159;",

        "\u00A1","&iexcl;",    //inverted (spanish) exclamation mark
        "\u00A2","&cent;",     //cent
        "\u00A3","&pound;",    //pound
        "\u00A4","&curren;",   //currency
        "\u00A5","&yen;",      //yen
        "\u00A6","&brvbar;",   //broken vertical bar
        "\u00A7","&sect;",     //section sign
        "\u00A8","&uml;",      //diaeresis (umlaut)
        "\u00A9","&copy;",     //copyright sign
        "\u00AA","&ordf;",     //feminine ordinal indicator
        "\u00AB","&laquo;",    //left-pointing double angle quotation mark
        "\u00AC","&not;",      //not sign
        "\u00AD","&shy;",      //soft hyphen
        "\u00AE","&reg;",      //registered sign
        "\u00AF","&macr;",     //macron
        "\u00B0","&deg;",      //degree sign
        "\u00B1","&plusmn;",   //plus-minus sign
        "\u00B2","&sup2;",     //superscript two
        "\u00B3","&sup3;",     //superscript three
        "\u00B4","&acute;",    //acute accent
        "\u00B5","&micro;",    //micro sign
        "\u00B6","&para;",     //paragraph sign
        "\u00B7","&middot;",   //middle dot
        "\u00B8","&cedil;",    //cedilla
        "\u00B9","&sup1;",     //superscript one
        "\u00BA","&ordm;",     //masculine ordinal indicator
        "\u00BB","&raquo;",    //right-pointing double angle quotation mark
        "\u00BC","&frac14;",   //fraction 1/4
        "\u00BD","&frac12;",   //fraction 1/2
        "\u00BE","&frac34;",   //fraction 3/4
        "\u00BF","&iquest;",   //inverted (spanisch) questionmark
        "\u00C0","&Agrave;",
        "\u00C1","&Aacute;",
        "\u00C2","&Acirc;",
        "\u00C3","&Atilde;",
        "\u00C4","&Auml;",
        "\u00C5","&Aring;",
        "\u00C6","&AElig;",
        "\u00C7","&Ccedil;",
        "\u00C8","&Egrave;",
        "\u00C9","&Eacute;",
        "\u00CA","&Ecirc;",
        "\u00CB","&Euml;",
        "\u00CC","&Igrave;",
        "\u00CD","&Iacute;",
        "\u00CE","&Icirc;",
        "\u00CF","&Iuml;",
        "\u00D0","&ETH;",
        "\u00D1","&Ntilde;",
        "\u00D2","&Ograve;",
        "\u00D3","&Oacute;",
        "\u00D4","&Ocirc;",
        "\u00D5","&Otilde;",
        "\u00D6","&Ouml;",
        "\u00D7","&times;",
        "\u00D8","&Oslash;",
        "\u00D9","&Ugrave;",
        "\u00DA","&Uacute;",
        "\u00DB","&Ucirc;",
        "\u00DC","&Uuml;",
        "\u00DD","&Yacute;",
        "\u00DE","&THORN;",
        "\u00DF","&szlig;",
        "\u00E0","&agrave;",
        "\u00E1","&aacute;",
        "\u00E2","&acirc;",
        "\u00E3","&atilde;",
        "\u00E4","&auml;",
        "\u00E5","&aring;",
        "\u00E6","&aelig;",
        "\u00E7","&ccedil;",
        "\u00E8","&egrave;",
        "\u00E9","&eacute;",
        "\u00EA","&ecirc;",
        "\u00EB","&euml;",
        "\u00EC","&igrave;",
        "\u00ED","&iacute;",
        "\u00EE","&icirc;",
        "\u00EF","&iuml;",
        "\u00F0","&eth;",
        "\u00F1","&ntilde;",
        "\u00F2","&ograve;",
        "\u00F3","&oacute;",
        "\u00F4","&ocirc;",
        "\u00F5","&otilde;",
        "\u00F6","&ouml;",
        "\u00F7","&divide;",
        "\u00F8","&oslash;",
        "\u00F9","&ugrave;",
        "\u00FA","&uacute;",
        "\u00FB","&ucirc;",
        "\u00FC","&uuml;",
        "\u00FD","&yacute;",
        "\u00FE","&thorn;",
        "\u00FF","&yuml;",
        "(C)","&copy;"
    };

    /** This method processes tables in the wiki code.
      * @param a string that might contain parts of a table
      * @return a string with wiki code of parts of table replaced by HTML code for table
      */
      //[FB], changes by [MN]
    private String processTable(String result, plasmaSwitchboard switchboard){
        //some variables that make it easier to change codes for the table
        String line = "";
        String tableStart = "&#123;&#124;";                 // {|
        String newLine = "&#124;-";                         // |-
        String cellDivider = "&#124;&#124;";                // ||
        String tableEnd = "&#124;&#125;";                   // |}
        String attribDivider = "&#124;";                    // |
        int lenTableStart = tableStart.length();
        int lenCellDivider = cellDivider.length();
        int lenTableEnd = tableEnd.length();
        int lenAttribDivider = attribDivider.length();

        if ((result.startsWith(tableStart)) && (!table)) {
            table=true;
            newrowstart=true;
            line="<table";
            if (result.trim().length()>lenTableStart) {
                line+=parseTableProperties(result.substring(lenTableStart).trim());
            }
            line+=">";
            result=line;
        }
        else if (result.startsWith(newLine) && (table)) {          // new row
            if (!newrowstart) {
                line+="\t</tr>\n";
            } else {
                newrowstart=false;
            }
            line=line+"\t<tr>";
            result=line;
        }
        else if ((result.startsWith(cellDivider)) && (table)) {
            line+="\t\t<td";
            int cellEnd=(result.indexOf(cellDivider,lenCellDivider)>0)?(result.indexOf(cellDivider,lenCellDivider)):(result.length());
            int propEnd = result.indexOf(attribDivider,lenCellDivider);
            int occImage = result.indexOf("[[Image:",lenCellDivider);
            int occEscape = result.indexOf("[=",lenCellDivider);
            //If resultOf("[[Image:") is less than propEnd, that means that there is no
            //property for this cell, only an image. Without this, YaCy could get confused
            //by a | in [[Image:picture.png|alt-text]] or [[Image:picture.png|alt-text]]
            //Same for [= (part of [= =])
            if((propEnd > lenCellDivider)
            &&((occImage > propEnd)||( occImage < 0))
            &&((occEscape> propEnd)||( occEscape < 0))
            ){
                propEnd = result.indexOf(attribDivider,lenCellDivider)+lenAttribDivider;
            }
            else {
                propEnd = cellEnd;
            }
            // both point at same place => new line
            if (propEnd==cellEnd) {
                propEnd=lenCellDivider;
            }
            else {
                line+=parseTableProperties(result.substring(lenCellDivider,propEnd-lenAttribDivider).trim());
            }
            // quick&dirty fix for http://www.yacy-forum.de/viewtopic.php?t=2825 [MN]
            if(propEnd > cellEnd){
                propEnd = lenCellDivider;
            }
            table=false; cellprocessing=true;
            line+=">"+processTable(result.substring(propEnd,cellEnd).trim(), switchboard)+"</td>";
            table=true; cellprocessing=false;
            if (cellEnd<result.length()) {
                line+="\n"+processTable(result.substring(cellEnd), switchboard);
            }
            result=line;
        }
        else if (result.startsWith(tableEnd) && (table)) {          // Table end
            table=false;
            line+="\t</tr>\n</table>"+result.substring(lenTableEnd);
            result=line;
        }
        return result;
    }

    //contributed by [MN]
    /** This method takes possible table properties and tests if they are valid.
      * Valid in this case means if they are a property for the table, tr or td
      * tag as stated in the HTML Pocket Reference by Jennifer Niederst (1st edition)
      * The method is important to avoid XSS attacks on the wiki via table properties.
      * @param str A string that may contain several table properties and/or junk.
      * @return A string that only contains table properties.
      */
    private String parseTableProperties(String str){
        str = str.replaceAll("&quot;", "");      //killing all quotationmarks
        String[] values = str.split("[= ]");     //splitting the string at = and blanks
        str="";                                  //recycling... ;-)
        int numberofvalues = values.length;
        for(int i=0;i<numberofvalues;i++){
            if((values[i].equals("rowspan")) ||
               (values[i].equals("colspan")) ||
               (values[i].equals("vspace")) ||
               (values[i].equals("hspace")) ||
               (values[i].equals("cellspacing")) ||
               (values[i].equals("cellpadding")) ||
               (values[i].equals("border"))){
                if(i+1<numberofvalues){
                    if(values[i+1].matches("\\d+")){
                        str = str + " "+values[i]+"=\""+values[i+1]+"\"";
                        i++;
                    }
                }
            }
            else if((values[i].equals("width"))||(values[i].equals("height"))){
                if(i+1<numberofvalues){
                    if(values[i+1].matches("\\d+%{0,1}")){
                        str = str + " "+values[i]+"=\""+values[i+1]+"\"";
                        i++;
                    }
                }
            }
            else if(values[i].equals("align")){
                if(i+1<numberofvalues) {
                    if((values[i+1].equals("left")) ||
                       (values[i+1].equals("right")) ||
                       (values[i+1].equals("center"))) {
                        str = str + " "+values[i]+"=\""+values[i+1]+"\"";
                        i++;
                    }
                }
            }
            else if(values[i].equals("valign")){
                if(i+1<numberofvalues) {
                    if((values[i+1].equals("top")) ||
                       (values[i+1].equals("middle")) ||
                       (values[i+1].equals("bottom")) ||
                       (values[i+1].equals("baseline"))) {
                        str = str + " "+values[i]+"=\""+values[i+1]+"\"";
                        i++;
                    }
                }
            }
            else if(values[i].equals("bgcolor")){
                if(i+1<numberofvalues){
                    if(values[i+1].matches("#{0,1}[0-9a-fA-F]{1,6}|[a-zA-Z]{3,}")){
                        str = str + " "+values[i]+"=\""+values[i+1]+"\"";
                        i++;
                    }
                }
            }
            else if(values[i].equals("rules")){
                if(i+1<numberofvalues) {
                    if((values[i+1].equals("none")) ||
                       (values[i+1].equals("groups")) ||
                       (values[i+1].equals("rows")) ||
                       (values[i+1].equals("cols")) ||
                       (values[i+1].equals("all"))) {
                        str = str + " "+values[i]+"=\""+values[i+1]+"\"";
                        i++;
                    }
                }
            }
            else if(values[i].equals("frame")){
                if(i+1<numberofvalues) {
                    if((values[i+1].equals("void")) ||
                       (values[i+1].equals("above")) ||
                       (values[i+1].equals("below")) ||
                       (values[i+1].equals("hsides")) ||
                       (values[i+1].equals("lhs")) ||
                       (values[i+1].equals("rhs")) ||
                       (values[i+1].equals("vsides")) ||
                       (values[i+1].equals("box")) ||
                       (values[i+1].equals("border"))) {
                        str = str + " "+values[i]+"=\""+values[i+1]+"\"";
                        i++;
                    }
                }
            }
            else if(values[i].equals("summary")){
                if(i+1<numberofvalues){
                    str = str + " "+values[i]+"=\""+values[i+1]+"\"";
                    i++;
                }
            }
            else if(values[i].equals("nowrap")){
                str = str + " nowrap";
            }
        }
        return str;
    } //end contrib [MN]

    /** This method processes ordered lists.
      */
    private String orderedList(String result){
        if(!nolist){    //lists only get processed if not forbidden (see code for [= and <pre>). [MN]
            int p0 = 0;
            int p1 = 0;
            //# sorted Lists contributed by [AS]
            //## Sublist
            if(result.startsWith(numListLevel + "#")){ //more #
                p0 = result.indexOf(numListLevel);
                p1 = result.length();
                result = "<ol>" + serverCore.crlfString +
                    "<li>" +
                    result.substring(numListLevel.length() + 1, p1) +
                    "</li>";
                numListLevel += "#";
            }else if(numListLevel.length() > 0 && result.startsWith(numListLevel)){ //equal number of #
                p0 = result.indexOf(numListLevel);
                p1 = result.length();
                result = "<li>" +
                    result.substring(numListLevel.length(), p1) +
                    "</li>";
            }else if(numListLevel.length() > 0){ //less #
                int i = numListLevel.length();
                String tmp = "";

                while(! result.startsWith(numListLevel.substring(0,i)) ){
                    tmp += "</ol>";
                    i--;
                }
                numListLevel = numListLevel.substring(0,i);
                p0 = numListLevel.length();
                p1 = result.length();

                if(numListLevel.length() > 0){
                    result = tmp +
                         "<li>" +
                        result.substring(p0, p1) +
                        "</li>";
                }else{
                    result = tmp + result.substring(p0, p1);
                }
            }
            // end contrib [AS]
        }
        return result;
    }

    /** This method processes unordered lists.
      */
    //contributed by [AS] put into it's own method by [MN]
    private String unorderedList(String result){
        if(!nolist){    //lists only get processed if not forbidden (see code for [= and <pre>). [MN]
            int p0 = 0;
            int p1 = 0;
            //contributed by [AS]
            if(result.startsWith(ListLevel + "*")){ //more stars
               p0 = result.indexOf(ListLevel);
                p1 = result.length();
                result = "<ul>" + serverCore.crlfString +
                    "<li>" +
                result.substring(ListLevel.length() + 1, p1) +
                    "</li>";
                ListLevel += "*";
            }else if(ListLevel.length() > 0 && result.startsWith(ListLevel)){ //equal number of stars
                p0 = result.indexOf(ListLevel);
                p1 = result.length();
                result = "<li>" +
                    result.substring(ListLevel.length(), p1) +
                    "</li>";
            }else if(ListLevel.length() > 0){ //less stars
                int i = ListLevel.length();
                String tmp = "";

                while(! result.startsWith(ListLevel.substring(0,i))){
                    tmp += "</ul>";
                    i--;
                }
                ListLevel = ListLevel.substring(0,i);
                p0 = ListLevel.length();
                p1 = result.length();

                if(ListLevel.length() > 0){
                    result = tmp +
                        "<li>" +
                        result.substring(p0, p1) +
                        "</li>";
                }else{
                    result = tmp + result.substring(p0, p1);
                }
            }
            //end contrib [AS]
        }
        return result;
    }

    /** This method processes definition lists.
      */
    //contributed by [MN] based on unordered list code by [AS]
    private String definitionList(String result){
        if(!nolist){    //lists only get processed if not forbidden (see code for [= and <pre>). [MN]
            int p0 = 0;
            int p1 = 0;
            if(result.startsWith(defListLevel + ";")){ //more semicolons
                String dt = ""; 
                String dd = "";
                p0 = result.indexOf(defListLevel);
                p1 = result.length();
                String resultCopy = result.substring(defListLevel.length() + 1, p1);
                if((p0 = resultCopy.indexOf(":")) > 0){
                    dt = resultCopy.substring(0,p0);
                    dd = resultCopy.substring(p0+1);
                    result = "<dl>" + "<dt>" + dt + "</dt>" + "<dd>" + dd;
                    defList = true;
                }
                defListLevel += ";";
            }else if(defListLevel.length() > 0 && result.startsWith(defListLevel)){ //equal number of semicolons
                String dt = ""; 
                String dd = "";
                p0 = result.indexOf(defListLevel);
                p1 = result.length();
                String resultCopy = result.substring(defListLevel.length(), p1);
                if((p0 = resultCopy.indexOf(":")) > 0){
                    dt = resultCopy.substring(0,p0);
                    dd = resultCopy.substring(p0+1);
                    result = "<dt>" + dt + "</dt>" + "<dd>" + dd;
                    defList = true;
                }
            }else if(defListLevel.length() > 0){ //less semicolons
                String dt = ""; 
                String dd = "";
                int i = defListLevel.length();
                String tmp = "";
                while(! result.startsWith(defListLevel.substring(0,i)) ){
                    tmp += "</dd></dl>";
                    i--;
                }
                defListLevel = defListLevel.substring(0,i);
                p0 = defListLevel.length();
                p1 = result.length();
                if(defListLevel.length() > 0){
                    String resultCopy = result.substring(p0, p1);
                    if((p0 = resultCopy.indexOf(":")) > 0){
                        dt = resultCopy.substring(0,p0);
                        dd = resultCopy.substring(p0+1);
                        result = tmp + "<dt>" + dt + "</dt>" + "<dd>" + dd;
                        defList = true;
                    }
                }else{
                    result = tmp + result.substring(p0, p1);
                }
            }
        }
        return result; 
    }

    /** This method processes links and images.
      */
    //contributed by [AS] except where stated otherwise
    private String linksAndImages(String result, plasmaSwitchboard switchboard){

        // create links
        String kl, kv, alt, align;
        int p;
        int p0 = 0;
        int p1 = 0;
        // internal links and images
        while ((p0 = result.indexOf("[[")) >= 0) {
            p1 = result.indexOf("]]", p0 + 2);
            if (p1 <= p0) break;
            kl = result.substring(p0 + 2, p1);

            // this is the part of the code that's responsible for images
            // contributed by [MN]
            if (kl.startsWith("Image:")) {
                alt = "";
                align = "";
                kv = "";
                kl = kl.substring(6);

                // are there any arguments for the image?
                if ((p = kl.indexOf("&#124;")) > 0) {
                    kv = kl.substring(p + 6);
                    kl = kl.substring(0, p);
                    // if there are 2 arguments, write them into ALIGN and ALT
                    if ((p = kv.indexOf("&#124;")) > 0) {
                        align = kv.substring(0, p);
                        //checking validity of value for align. Only non browser specific
                        //values get supported. Not supported: absmiddle, baseline, texttop
                        if ((align.equals("bottom"))||
                            (align.equals("center"))||
                            (align.equals("left"))||
                            (align.equals("middle"))||
                            (align.equals("right"))||
                            (align.equals("top")))
                        {
                            align = " align=\"" + align + "\"";
                        }
                        else align = "";
                        alt = " alt=\"" + kv.substring(p + 6) + "\"";
                    }
                    // if there is just one, put it into ALT
                    else
                        alt = " alt=\"" + kv + "\"";
                }

                // replace incomplete URLs and make them point to http://peerip:port/...
                // with this feature you can access an image in DATA/HTDOCS/share/yacy.gif
                // using the wikicode [[Image:share/yacy.gif]]
                // or an image DATA/HTDOCS/grafics/kaskelix.jpg with [[Image:grafics/kaskelix.jpg]]
                // you are free to use other sub-paths of DATA/HTDOCS
                if (kl.indexOf("://")<1) {
                    kl = "http://" + yacyCore.seedDB.mySeed.getAddress().trim() + "/" + kl;
                }

                result = result.substring(0, p0) + "<img src=\"" + kl + "\"" + align + alt + ">" + result.substring(p1 + 2);
            }
            // end contrib [MN]

            // if it's no image, it might be an internal link
            else {
                if ((p = kl.indexOf("&#124;")) > 0) {
                    kv = kl.substring(p + 6);
                    kl = kl.substring(0, p);
                } else {
                    kv = kl;
                }
                if (switchboard.wikiDB.read(kl) != null)
                    result = result.substring(0, p0) + "<a class=\"known\" href=\"Wiki.html?page=" + kl + "\">" + kv + "</a>" + result.substring(p1 + 2);
                else
                    result = result.substring(0, p0) + "<a class=\"unknown\" href=\"Wiki.html?page=" + kl + "&edit=Edit\">" + kv + "</a>" + result.substring(p1 + 2);
            }
        }

        // external links
        while ((p0 = result.indexOf("[")) >= 0) {
            p1 = result.indexOf("]", p0 + 1);
            if (p1 <= p0) break;
            kl = result.substring(p0 + 1, p1);
            if ((p = kl.indexOf(" ")) > 0) {
                kv = kl.substring(p + 1);
                kl = kl.substring(0, p);
            }
            // No text for the link? -> <a href="http://www.url.com/">http://www.url.com/</a>
            else {
                kv = kl;
            }
            // replace incomplete URLs and make them point to http://peerip:port/...
            // with this feature you can access a file at DATA/HTDOCS/share/page.html
            // using the wikicode [share/page.html]
            // or a file DATA/HTDOCS/www/page.html with [www/page.html]
            // you are free to use other sub-paths of DATA/HTDOCS
            if (kl.indexOf("://")<1) {
                kl = "http://" + yacyCore.seedDB.mySeed.getAddress().trim() + "/" + kl;
            }
        result = result.substring(0, p0) + "<a class=\"extern\" href=\"" + kl + "\">" + kv + "</a>" + result.substring(p1 + 1);
        }
        return result;
    }

    /** This method handles the escape tags [= =] */
    //contributed by [MN]
    private String escapeTag(String result, plasmaSwitchboard switchboard){
        int p0 = 0;
        int p1 = 0;
        //both [= and =] in the same line
        if(((p0 = result.indexOf("[="))>=0)&&((p1 = result.indexOf("=]"))>0)&&(!(preformatted))){
            if(p0<p1){
                String escapeText = result.substring(p0+2,p1);
                escapeText = escapeText.replaceAll("!esc!", "!esc!!");
                result = transformLine(result.substring(0,p0).replaceAll("!esc!", "!esc!!")+"!esc!txt!"+result.substring(p1+2).replaceAll("!esc!", "!esc!!"), switchboard);
                result = result.replaceAll("!esc!txt!", escapeText);
                result = result.replaceAll("!esc!!", "!esc!");
            }
            //handles cases like [=[= =]=] [= =] that would cause an exception otherwise
            else{
                escape = true;
                String temp1 = transformLine(result.substring(0,p0-1).replaceAll("!tmp!","!tmp!!")+"!tmp!txt!", switchboard);
                nolist = true;
                String temp2 = transformLine(result.substring(p0), switchboard);
                nolist = false;
                result = temp1.replaceAll("!tmp!txt!",temp2);
                result = result.replaceAll("!tmp!!", "!tmp!");
                escape = false;
            }
        }

        //start [=
        else if(((p0 = result.indexOf("[="))>=0)&&(!escapeSpan)&&(!preformatted)){
            escape = true;    //prevent surplus line breaks
            escaped = true;   //prevents <pre> being parsed
            String bq = "";   //gets filled with <blockquote>s as needed
            String escapeText = result.substring(p0+2);
            escapeText = escapeText.replaceAll("!esc!", "!esc!!");
            //taking care of indented lines
            while(result.substring(escindented,p0).startsWith(":")){
                escindented++;
                bq = bq + "<blockquote>";
            }
            result = transformLine(result.substring(escindented,p0).replaceAll("!esc!", "!esc!!")+"!esc!txt!", switchboard);
            result = bq + result.replaceAll("!esc!txt!", escapeText);
            result = result.replaceAll("!esc!!", "!esc!");
            escape = false;
            escapeSpan = true;
        }

        //end =]
        else if(((p0 = result.indexOf("=]"))>=0)&&(escapeSpan)&&(!preformatted)){
            escapeSpan = false;
            String bq = ""; //gets filled with </blockquote>s as needed
            String escapeText = result.substring(0,p0);
            escapeText = escapeText.replaceAll("!esc!", "!esc!!");
            //taking care of indented lines
            while(escindented > 0){
                bq = bq + "</blockquote>";
                escindented--;
            }
            result = transformLine("!esc!txt!"+result.substring(p0+2).replaceAll("!esc!", "!esc!!"), switchboard);
            result = result.replaceAll("!esc!txt!", escapeText) + bq;
            result = result.replaceAll("!esc!!", "!esc!");
            escaped = false;
        }
        //Getting rid of surplus =]
        else if (((p0 = result.indexOf("=]"))>=0)&&(!escapeSpan)&&(!preformatted)){
            while((p0 = result.indexOf("=]"))>=0){
                result = result.substring(0,p0)+result.substring(p0+2);
            }
            result = transformLine(result, switchboard);
        }
        return result;
    }

    /** This method handles the preformatted tags <pre> </pre> */
    //contributed by [MN]
    private String preformattedTag(String result, plasmaSwitchboard switchboard){
        int p0 = 0;
        int p1 = 0;
        //implementation very similar to escape code (see above)
        //both <pre> and </pre> in the same line
        if(((p0=result.indexOf("&lt;pre&gt;"))>=0)&&((p1=result.indexOf("&lt;/pre&gt;"))>0)&&(!(escaped))){
            if(p0<p1){
                String preformattedText = "<pre style=\"border:dotted;border-width:thin\">"+result.substring(p0+11,p1)+"</pre>";
                preformattedText = preformattedText.replaceAll("!pre!", "!pre!!");
                result = transformLine(result.substring(0,p0).replaceAll("!pre!", "!pre!!")+"!pre!txt!"+result.substring(p1+12).replaceAll("!pre!", "!pre!!"), switchboard);
                result = result.replaceAll("!pre!txt!", preformattedText);
                result = result.replaceAll("!pre!!", "!pre!");
            }
            //handles cases like <pre><pre> </pre></pre> <pre> </pre> that would cause an exception otherwise
            else{
                preformatted = true;
                String temp1 = transformLine(result.substring(0,p0-1).replaceAll("!tmp!","!tmp!!")+"!tmp!txt!", switchboard);
                nolist = true;
                String temp2 = transformLine(result.substring(p0), switchboard);
                nolist = false;
                result = temp1.replaceAll("!tmp!txt!",temp2);
                result = result.replaceAll("!tmp!!", "!tmp!");
                preformatted = false;
            }
        }

        //start <pre>
        else if(((p0 = result.indexOf("&lt;pre&gt;"))>=0)&&(!preformattedSpan)&&(!escaped)){
            preformatted = true;    //prevent surplus line breaks
            String bq ="";  //gets filled with <blockquote>s as needed
            String preformattedText = "<pre style=\"border:dotted;border-width:thin\">"+result.substring(p0+11);
            preformattedText = preformattedText.replaceAll("!pre!", "!pre!!");
            //taking care of indented lines
            while(result.substring(preindented,p0).startsWith(":")){
                preindented++;
                bq = bq + "<blockquote>";
            }
            result = transformLine(result.substring(preindented,p0).replaceAll("!pre!", "!pre!!")+"!pre!txt!", switchboard);
            result = bq + result.replaceAll("!pre!txt!", preformattedText);
            result = result.replaceAll("!pre!!", "!pre!");
            preformattedSpan = true;
        }

        //end </pre>
        else if(((p0 = result.indexOf("&lt;/pre&gt;"))>=0)&&(preformattedSpan)&&(!escaped)){
            preformattedSpan = false;
            String bq = ""; //gets filled with </blockquote>s as needed
            String preformattedText = result.substring(0,p0)+"</pre>";
            preformattedText = preformattedText.replaceAll("!pre!", "!pre!!");
                //taking care of indented lines
            while (preindented > 0){
                bq = bq + "</blockquote>";
                preindented--;
            }
            result = transformLine("!pre!txt!"+result.substring(p0+12).replaceAll("!pre!", "!pre!!"), switchboard);
            result = result.replaceAll("!pre!txt!", preformattedText) + bq;
            result = result.replaceAll("!pre!!", "!pre!");
            preformatted = false;
        }
        //Getting rid of surplus </pre>
        else if (((p0 = result.indexOf("&lt;/pre&gt;"))>=0)&&(!preformattedSpan)&&(!escaped)){
            while((p0 = result.indexOf("&lt;/pre&gt;"))>=0){
                result = result.substring(0,p0)+result.substring(p0+12);
            }
            result = transformLine(result, switchboard);
        }
        return result;
    }

    /** This method creates a directory for a wiki page.
      * @return directory of the wiki
      */
    //method contributed by [MN]
    private String directory(){
        String directory = "";
        String element;
        int s = 0;
        int level = 1;
        int level1 = 0;
        int level2 = 0;
        int level3 = 0;
        int doubles = 0;
        String anchorext = "";
        if((s=dirElements.size())>2){
            for(int i=0;i<s;i++){
                element = dirElements.get(i).toString();
                //counting double headlines
                doubles = 0;
                for(int j=0;j<i;j++){
                    if(dirElements.get(j).toString().substring(1).replaceAll(" ","_").replaceAll("[^a-zA-Z0-9_]","").equals(element.substring(1).replaceAll(" ","_").replaceAll("[^a-zA-Z0-9_]",""))){
                        doubles++;
                    }
                }
                //if there are doubles, create anchorextension
                if(doubles>0){
                    anchorext = "_" + (doubles+1);
                }

                if (element.startsWith("3")){
                    if(level<3){
                        level = 3;
                        level3 = 0;
                    }
                    level3++;
                    String temp = element.substring(1);
                    element=level1+"."+level2+"."+level3+" "+temp;
                    directory = directory + "&nbsp;&nbsp;&nbsp;&nbsp;<a href=\"#"+temp.replaceAll(" ","_").replaceAll("[^a-zA-Z0-9_]","")+anchorext+"\" class=\"WikiTOC\">"+element+"</a><br>\n";
                }
                else if (element.startsWith("2")){
                    if(level==1){
                        level2 = 0;
                        level = 2;
                    }
                    if(level==3){
                        level = 2;
                    }
                    level2++;
                    String temp = element.substring(1);
                    element=level1+"."+level2+" "+temp;
                    directory = directory + "&nbsp;&nbsp;<a href=\"#"+temp.replaceAll(" ","_").replaceAll("[^a-zA-Z0-9_]","")+anchorext+"\" class=\"WikiTOC\">"+element+"</a><br>\n";
                }
                else if (element.startsWith("1")) {
                    if (level>1) {
                        level = 1;
                        level2 = 0;
                        level3 = 0;
                    }
                    level1++;
                    String temp = element.substring(1);
                    element=level1+". "+temp;
                    directory = directory + "<a href=\"#"+temp.replaceAll(" ","_").replaceAll("[^a-zA-Z0-9_]","")+anchorext+"\" class=\"WikiTOC\">"+element+"</a><br>\n";
                }
                anchorext="";
            }
            directory = "<table><tr><td><div class=\"WikiTOCBox\">\n" + directory + "</div></td></tr></table>\n";
        }
        return directory;
    }

    /** Replaces two occurences of a substring in a string by a pair of strings if 
      * that substring occurs twice in the string. This method is not greedy! You'll
      * have to run it in a loop if you want to replace all occurences of the substring.
      * This method provides special treatment for headlines.
      * @param input the string that something is to be replaced in
      * @param pat substring to be replaced
      * @param repl1 string substring gets replaced by on uneven occurences
      * @param repl2 string substring gets replaced by on even occurences
      */
      //[MN]
    private String pairReplace(String input, String pat, String repl1, String repl2){
        String direlem = "";    //string to keep headlines until they get added to List dirElements
        int p0 = 0;
        int p1 = 0;
        int l = pat.length();
        if ((p0 = input.indexOf(pat)) >= 0) {
            p1 = input.indexOf(pat, p0 + l);
            if (p1 >= 0) {
                //extra treatment for headlines
                if((pat.equals("===="))||(pat.equals("==="))||(pat.equals("=="))){
                    //add anchor and create headline
                    direlem = input.substring(p0 + l, p1);
                    //counting double headlines
                    int doubles = 0;
                    for(int i=0;i<headlines;i++){
                        if(dirElements.get(i).toString().substring(1).equals(direlem)){
                            doubles++;
                        }
                    }
                    String anchor = direlem.replaceAll(" ","_").replaceAll("[^a-zA-Z0-9_]",""); //replace blanks with underscores and delete everything thats not a regular character, a number or _
                    //if there are doubles, add underscore and number of doubles plus one
                    if(doubles>0){
                        anchor = anchor + "_" + (doubles+1);
                    }
                    input = input.substring(0, p0) + "<a name=\""+anchor+"\"></a>" + repl1 +
                    direlem + repl2 + input.substring(p1 + l);
                    //add headlines to list of headlines (so TOC can be created)
                    if(pat.equals("===="))     dirElements.add("3"+direlem);
                    else if(pat.equals("===")) dirElements.add("2"+direlem);
                    else if(pat.equals("=="))  dirElements.add("1"+direlem);
                    headlines++;
                }
                else{
                    input = input.substring(0, p0) +  repl1 +
                    (direlem = input.substring(p0 + l, p1)) + repl2 +
                    input.substring(p1 + l);
                }
            }
        }
        return input;
    }

    /** Replaces wiki tags with HTML tags.
      * @param result a line of text
      * @param switchboard
      * @return the line of text with HTML tags instead of wiki tags
      */
    public String transformLine(String result, plasmaSwitchboard switchboard) {
        //If HTML has not bee replaced yet (can happen if method gets called in recursion), replace now!
        if (!replacedHTML || preformattedSpan){
            result = replaceXMLEntities(result);
            replacedHTML = true;
        }
        //If special characters have not bee replaced yet, replace now!
        if (!replacedCharacters || preformattedSpan){
            result = replaceHTMLEntities(result);
            replacedCharacters = true;
        }

        //check if line contains escape symbols([= =]) or if we are in an escape sequence already.
        if ((result.indexOf("[=")>=0)||(result.indexOf("=]")>=0)||(escapeSpan)){
                result = escapeTag(result, switchboard);
        }

        //check if line contains preformatted symbols or if we are in a preformatted sequence already.
        else if ((result.indexOf("&lt;pre&gt;")>=0)||(result.indexOf("&lt;/pre&gt;")>=0)||(preformattedSpan)){
                result = preformattedTag(result, switchboard);
        }

        //transform page as usual
        else {

            //tables first -> wiki-tags in cells can be treated after that
            result = processTable(result, switchboard);

            // format lines
            if (result.startsWith(" ")) result = "<tt>" + result + "</tt>";
            if (result.startsWith("----")) result = "<hr>";

            // citings contributed by [MN]
            if(result.startsWith(":")){
                String head = "";
                String tail = "";
                while(result.startsWith(":")){
                    head = head + "<blockquote>";
                    tail = tail + "</blockquote>";
                    result = result.substring(1);
                }
                result = head + result + tail;
            }
            // end contrib [MN]	

            // format headers
            result = pairReplace(result,"====","<h4>","</h4>");
            result = pairReplace(result,"===","<h3>","</h3>");
            result = pairReplace(result,"==","<h2>","</h2>");

            result = pairReplace(result,"'''''","<b><i>","</i></b>");
            result = pairReplace(result,"'''","<b>","</b>");
            result = pairReplace(result,"''","<i>","</i>");

            result = unorderedList(result);
            result = orderedList(result);
            result = definitionList(result);

            result = linksAndImages(result, switchboard);

        }

        if (!preformatted) replacedHTML = false;
        replacedCharacters = false;
        if ((result.endsWith("</li>"))||(defList)||(escape)||(preformatted)||(table)||(cellprocessing)) return result;
        return result + "<br>";
    }
}