/*
    Licensed to the Apache Software Foundation (ASF) under one
    or more contributor license agreements.  See the NOTICE file
    distributed with this work for additional information
    regarding copyright ownership.  The ASF licenses this file
    to you under the Apache License, Version 2.0 (the
    "License"); you may not use this file except in compliance
    with the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing,
    software distributed under the License is distributed on an
    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    KIND, either express or implied.  See the License for the
    specific language governing permissions and limitations
    under the License.
 */
package org.apache.wiki.parser;

import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.EmptyStackException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.ResourceBundle;
import java.util.Stack;

import javax.xml.transform.Result;

import org.apache.commons.lang.StringEscapeUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
import org.apache.oro.text.regex.MalformedPatternException;
import org.apache.oro.text.regex.MatchResult;
import org.apache.oro.text.regex.Pattern;
import org.apache.oro.text.regex.PatternCompiler;
import org.apache.oro.text.regex.PatternMatcher;
import org.apache.oro.text.regex.Perl5Compiler;
import org.apache.oro.text.regex.Perl5Matcher;
import org.apache.wiki.InternalWikiException;
import org.apache.wiki.StringTransmutator;
import org.apache.wiki.WikiContext;
import org.apache.wiki.WikiPage;
import org.apache.wiki.api.exceptions.PluginException;
import org.apache.wiki.api.plugin.WikiPlugin;
import org.apache.wiki.auth.WikiSecurityException;
import org.apache.wiki.auth.acl.Acl;
import org.apache.wiki.i18n.InternationalizationManager;
import org.apache.wiki.preferences.Preferences;
import org.apache.wiki.render.CleanTextRenderer;
import org.apache.wiki.render.RenderingManager;
import org.apache.wiki.util.TextUtil;
import org.jdom2.Attribute;
import org.jdom2.Content;
import org.jdom2.Element;
import org.jdom2.IllegalDataException;
import org.jdom2.ProcessingInstruction;
import org.jdom2.Verifier;

/**
 *  Parses JSPWiki-style markup into a WikiDocument DOM tree.  This class is the
 *  heart and soul of JSPWiki : make sure you test properly anything that is added,
 *  or else it breaks down horribly.
 *
 *  @since  2.4
 */
public class JSPWikiMarkupParser extends MarkupParser {

    protected static final int              READ          = 0;
    protected static final int              EDIT          = 1;
    protected static final int              EMPTY         = 2;  // Empty message
    protected static final int              LOCAL         = 3;
    protected static final int              LOCALREF      = 4;
    protected static final int              IMAGE         = 5;
    protected static final int              EXTERNAL      = 6;
    protected static final int              INTERWIKI     = 7;
    protected static final int              IMAGELINK     = 8;
    protected static final int              IMAGEWIKILINK = 9;
    protected static final int              ATTACHMENT    = 10;

    private static Logger log = Logger.getLogger( JSPWikiMarkupParser.class );

    private boolean        m_isbold       = false;
    private boolean        m_isitalic     = false;
    private boolean        m_istable      = false;
    private boolean        m_isPre        = false;
    private boolean        m_isEscaping   = false;
    private boolean        m_isdefinition = false;
    private boolean        m_isPreBlock   = false;

    /** Contains style information, in multiple forms. */
    private Stack<Boolean> m_styleStack   = new Stack<>();

     // general list handling
    private int            m_genlistlevel = 0;
    private StringBuilder  m_genlistBulletBuffer = new StringBuilder(10);  // stores the # and * pattern
    private boolean        m_allowPHPWikiStyleLists = true;

    private boolean        m_isOpenParagraph = false;

    /** Parser for extended link functionality. */
    private LinkParser     m_linkParser = new LinkParser();

    /** Keeps track of any plain text that gets put in the Text nodes */
    private StringBuilder  m_plainTextBuf = new StringBuilder(20);

    private Element        m_currentElement;

    /** Keep track of duplicate header names.  */
    private Map<String, Integer>   m_titleSectionCounter = new HashMap<>();

    /** If true, consider CamelCase hyperlinks as well. */
    public static final String     PROP_CAMELCASELINKS   = "jspwiki.translatorReader.camelCaseLinks";

    /** If true, all hyperlinks are translated as well, regardless whether they
        are surrounded by brackets. */
    public static final String     PROP_PLAINURIS        = "jspwiki.translatorReader.plainUris";

    /** If true, all outward attachment info links have a small link image appended. */
    public static final String     PROP_USEATTACHMENTIMAGE = "jspwiki.translatorReader.useAttachmentImage";

    /** If true, then considers CamelCase links as well. */
    private boolean                m_camelCaseLinks      = false;

    /** If true, then generate special output for wysiwyg editing in certain cases */
    private boolean                m_wysiwygEditorMode     = false;

    /** If true, consider URIs that have no brackets as well. */
    // FIXME: Currently reserved, but not used.
    private boolean                m_plainUris           = false;

    /** If true, all outward links use a small link image. */
    private boolean                m_useOutlinkImage     = true;

    private boolean                m_useAttachmentImage  = true;

    /** If true, allows raw HTML. */
    private boolean                m_allowHTML           = false;

    private boolean                m_useRelNofollow      = false;

    private PatternCompiler        m_compiler = new Perl5Compiler();

    static final String WIKIWORD_REGEX = "(^|[[:^alnum:]]+)([[:upper:]]+[[:lower:]]+[[:upper:]]+[[:alnum:]]*|(http://|https://|mailto:)([A-Za-z0-9_/\\.\\+\\?\\#\\-\\@=&;~%]+))";

    private PatternMatcher         m_camelCaseMatcher = new Perl5Matcher();
    private Pattern                m_camelCasePattern;

    private int                    m_rowNum              = 1;

    private Heading                m_lastHeading         = null;

    private static final String CAMELCASE_PATTERN     = "JSPWikiMarkupParser.camelCasePattern";

    /**
     *  Creates a markup parser.
     *
     *  @param context The WikiContext which controls the parsing
     *  @param in Where the data is read from.
     */
    public JSPWikiMarkupParser( WikiContext context, Reader in )
    {
        super( context, in );
        initialize();
    }

    // FIXME: parsers should be pooled for better performance.
    private void initialize()
    {
        initInlineImagePatterns();

        m_camelCasePattern = (Pattern) m_engine.getAttribute( CAMELCASE_PATTERN );
        if( m_camelCasePattern == null )
        {
            try
            {
                m_camelCasePattern = m_compiler.compile( WIKIWORD_REGEX,
                                                         Perl5Compiler.DEFAULT_MASK|Perl5Compiler.READ_ONLY_MASK );
            }
            catch( MalformedPatternException e )
            {
                log.fatal("Internal error: Someone put in a faulty pattern.",e);
                throw new InternalWikiException("Faulty camelcasepattern in TranslatorReader", e);
            }
            m_engine.setAttribute( CAMELCASE_PATTERN, m_camelCasePattern );
        }
        //
        //  Set the properties.
        //
        Properties props      = m_engine.getWikiProperties();

        String cclinks = (String)m_context.getPage().getAttribute( PROP_CAMELCASELINKS );

        if( cclinks != null )
        {
            m_camelCaseLinks = TextUtil.isPositive( cclinks );
        }
        else
        {
            m_camelCaseLinks  = TextUtil.getBooleanProperty( props,
                                                             PROP_CAMELCASELINKS,
                                                             m_camelCaseLinks );
        }

        Boolean wysiwygVariable = (Boolean)m_context.getVariable( RenderingManager.WYSIWYG_EDITOR_MODE );
        if( wysiwygVariable != null )
        {
            m_wysiwygEditorMode = wysiwygVariable.booleanValue();
        }

        m_plainUris           = m_context.getBooleanWikiProperty( PROP_PLAINURIS, m_plainUris );
        m_useOutlinkImage     = m_context.getBooleanWikiProperty( PROP_USEOUTLINKIMAGE, m_useOutlinkImage );
        m_useAttachmentImage  = m_context.getBooleanWikiProperty( PROP_USEATTACHMENTIMAGE, m_useAttachmentImage );
        m_allowHTML           = m_context.getBooleanWikiProperty( PROP_ALLOWHTML, m_allowHTML );
        m_useRelNofollow      = m_context.getBooleanWikiProperty( PROP_USERELNOFOLLOW, m_useRelNofollow );

        if( m_engine.getUserManager().getUserDatabase() == null || m_engine.getAuthorizationManager() == null )
        {
            disableAccessRules();
        }

        m_context.getPage().setHasMetadata();
    }

    /**
     *  Calls a transmutator chain.
     *
     *  @param list Chain to call
     *  @param text Text that should be passed to the mutate() method of each of the mutators in the chain.
     *  @return The result of the mutation.
     */
    protected String callMutatorChain( Collection< StringTransmutator > list, String text )
    {
        if( list == null || list.size() == 0 )
        {
            return text;
        }

        for( Iterator< StringTransmutator > i = list.iterator(); i.hasNext(); )
        {
            StringTransmutator m = i.next();

            text = m.mutate( m_context, text );
        }

        return text;
    }

    /**
     * Calls the heading listeners.
     *
     * @param param A Heading object.
     */
    protected void callHeadingListenerChain( Heading param )
    {
        List< HeadingListener > list = m_headingListenerChain;

        for( Iterator< HeadingListener > i = list.iterator(); i.hasNext(); )
        {
            HeadingListener h = i.next();

            h.headingAdded( m_context, param );
        }
    }

    /**
     *  Creates a JDOM anchor element.  Can be overridden to change the URL creation,
     *  if you really know what you are doing.
     *
     *  @param type One of the types above
     *  @param link URL to which to link to
     *  @param text Link text
     *  @param section If a particular section identifier is required.
     *  @return An A element.
     *  @since 2.4.78
     */
    protected Element createAnchor(int type, String link, String text, String section)
    {
        text = escapeHTMLEntities( text );
        section = escapeHTMLEntities( section );
        Element el = new Element("a");
        el.setAttribute("class",CLASS_TYPES[type]);
        el.setAttribute("href",link+section);
        el.addContent(text);
        return el;
    }

    private Element makeLink( int type, String link, String text, String section, Iterator< Attribute > attributes )
    {
        Element el = null;

        if( text == null ) text = link;

        text = callMutatorChain( m_linkMutators, text );

        section = (section != null) ? ("#"+section) : "";

        // Make sure we make a link name that can be accepted
        // as a valid URL.

        if( link.length() == 0 )
        {
            type = EMPTY;
        }
        ResourceBundle rb = Preferences.getBundle( m_context, InternationalizationManager.CORE_BUNDLE );

        switch(type)
        {
            case READ:
                el = createAnchor( READ, m_context.getURL(WikiContext.VIEW, link), text, section );
                break;

            case EDIT:
                el = createAnchor( EDIT, m_context.getURL(WikiContext.EDIT,link), text, "" );
                el.setAttribute("title", MessageFormat.format( rb.getString( "markupparser.link.create" ), link ) );

                break;

            case EMPTY:
                el = new Element("u").addContent(text);
                break;

                //
                //  These two are for local references - footnotes and
                //  references to footnotes.
                //  We embed the page name (or whatever WikiContext gives us)
                //  to make sure the links are unique across Wiki.
                //
            case LOCALREF:
                el = createAnchor( LOCALREF, "#ref-"+m_context.getName()+"-"+link, "["+text+"]", "" );
                break;

            case LOCAL:
                el = new Element("a").setAttribute("class",CLASS_FOOTNOTE);
                el.setAttribute("name", "ref-"+m_context.getName()+"-"+link.substring(1));
                el.addContent("["+text+"]");
                break;

                //
                //  With the image, external and interwiki types we need to
                //  make sure nobody can put in Javascript or something else
                //  annoying into the links themselves.  We do this by preventing
                //  a haxor from stopping the link name short with quotes in
                //  fillBuffer().
                //
            case IMAGE:
                el = new Element("img").setAttribute("class","inline");
                el.setAttribute("src",link);
                el.setAttribute("alt",text);
                break;

            case IMAGELINK:
                el = new Element("img").setAttribute("class","inline");
                el.setAttribute("src",link);
                el.setAttribute("alt",text);
                el = createAnchor(IMAGELINK,text,"","").addContent(el);
                break;

            case IMAGEWIKILINK:
                String pagelink = m_context.getURL(WikiContext.VIEW,text);
                el = new Element("img").setAttribute("class","inline");
                el.setAttribute("src",link);
                el.setAttribute("alt",text);
                el = createAnchor(IMAGEWIKILINK,pagelink,"","").addContent(el);
                break;

            case EXTERNAL:
                el = createAnchor( EXTERNAL, link, text, section );
                if( m_useRelNofollow ) el.setAttribute("rel","nofollow");
                break;

            case INTERWIKI:
                el = createAnchor( INTERWIKI, link, text, section );
                break;

            case ATTACHMENT:
                String attlink = m_context.getURL( WikiContext.ATTACH,
                                                   link );

                String infolink = m_context.getURL( WikiContext.INFO,
                                                    link );

                String imglink = m_context.getURL( WikiContext.NONE,
                                                   "images/attachment_small.png" );

                el = createAnchor( ATTACHMENT, attlink, text, "" );

                if(  m_engine.getAttachmentManager().forceDownload( attlink ) )
                {
                    el.setAttribute("download", "");
                }

                pushElement(el);
                popElement(el.getName());

                if( m_useAttachmentImage )
                {
                    el = new Element("img").setAttribute("src",imglink);
                    el.setAttribute("border","0");
                    el.setAttribute("alt","(info)");

                    el = new Element("a").setAttribute("href",infolink).addContent(el);
                    el.setAttribute("class","infolink");
                }
                else
                {
                    el = null;
                }
                break;

            default:
                break;
        }

        if( el != null && attributes != null )
        {
            while( attributes.hasNext() )
            {
                Attribute attr = attributes.next();
                if( attr != null )
                {
                    el.setAttribute(attr);
                }
            }
        }

        if( el != null )
        {
            flushPlainText();
            m_currentElement.addContent( el );
        }
        return el;
    }


    /**
     *  Figures out if a link is an off-site link.  This recognizes
     *  the most common protocols by checking how it starts.
     *
     *  @param link The link to check.
     *  @return true, if this is a link outside of this wiki.
     *  @since 2.4
     *  @deprecated - use {@link LinkParsingOperations#isExternalLink(String)} instead.
     */
    @Deprecated
    public static boolean isExternalLink( String link )
    {
        return new LinkParsingOperations(null).isExternalLink( link );
    }

    /**
     *  Returns true if the link is really command to insert
     *  a plugin.
     *  <P>
     *  Currently we just check if the link starts with "{INSERT",
     *  or just plain "{" but not "{$".
     *
     *  @param link Link text, i.e. the contents of text between [].
     *  @return True, if this link seems to be a command to insert a plugin here.
     *  @deprecated Use {@link LinkParsingOperations#isPluginLink(String)} instead,
     */
    @Deprecated
    public static boolean isPluginLink( String link )
    {
        return new LinkParsingOperations( null ).isPluginLink( link );
    }

    /**
     *  These are all of the HTML 4.01 block-level elements.
     */
    private static final String[] BLOCK_ELEMENTS = {
        "address", "blockquote", "div", "dl", "fieldset", "form",
        "h1", "h2", "h3", "h4", "h5", "h6",
        "hr", "noscript", "ol", "p", "pre", "table", "ul"
    };

    private static boolean isBlockLevel( String name )
    {
        return Arrays.binarySearch( BLOCK_ELEMENTS, name ) >= 0;
    }

    /**
     *  This method peeks ahead in the stream until EOL and returns the result.
     *  It will keep the buffers untouched.
     *
     *  @return The string from the current position to the end of line.
     */

    // FIXME: Always returns an empty line, even if the stream is full.
    private String peekAheadLine()
        throws IOException
    {
        String s = readUntilEOL().toString();

        if( s.length() > PUSHBACK_BUFFER_SIZE )
        {
            log.warn("Line is longer than maximum allowed size ("+PUSHBACK_BUFFER_SIZE+" characters.  Attempting to recover...");
            pushBack( s.substring(0,PUSHBACK_BUFFER_SIZE-1) );
        }
        else
        {
            try
            {
                pushBack( s );
            }
            catch( IOException e )
            {
                log.warn("Pushback failed: the line is probably too long.  Attempting to recover.");
            }
        }
        return s;
    }

    private int flushPlainText()
    {
        int numChars = m_plainTextBuf.length();

        if( numChars > 0 )
        {
            String buf;

            if( !m_allowHTML )
            {
                buf = escapeHTMLEntities(m_plainTextBuf.toString());
            }
            else
            {
                buf = m_plainTextBuf.toString();
            }
            //
            //  We must first empty the buffer because the side effect of
            //  calling makeCamelCaseLink() is to call this routine.
            //

            m_plainTextBuf = new StringBuilder(20);

            try
            {
                //
                //  This is the heaviest part of parsing, and therefore we can
                //  do some optimization here.
                //
                //  1) Only when the length of the buffer is big enough, we try to do the match
                //

                if( m_camelCaseLinks && !m_isEscaping && buf.length() > 3 )
                {
                    // System.out.println("Buffer="+buf);

                    while( m_camelCaseMatcher.contains( buf, m_camelCasePattern ) )
                    {
                        MatchResult result = m_camelCaseMatcher.getMatch();

                        String firstPart = buf.substring(0,result.beginOffset(0));
                        String prefix = result.group(1);

                        if( prefix == null ) prefix = "";

                        String camelCase = result.group(2);
                        String protocol  = result.group(3);
                        String uri       = protocol+result.group(4);
                        buf              = buf.substring(result.endOffset(0));

                        m_currentElement.addContent( firstPart );

                        //
                        //  Check if the user does not wish to do URL or WikiWord expansion
                        //
                        if( prefix.endsWith("~") || prefix.indexOf('[') != -1 )
                        {
                            if( prefix.endsWith("~") )
                            {
                                if( m_wysiwygEditorMode )
                                {
                                    m_currentElement.addContent( "~" );
                                }
                                prefix = prefix.substring(0,prefix.length()-1);
                            }
                            if( camelCase != null )
                            {
                                m_currentElement.addContent( prefix+camelCase );
                            }
                            else if( protocol != null )
                            {
                                m_currentElement.addContent( prefix+uri );
                            }
                            continue;
                        }

                        //
                        //  Fine, then let's check what kind of a link this was
                        //  and emit the proper elements
                        //
                        if( protocol != null )
                        {
                            char c = uri.charAt(uri.length()-1);
                            if( c == '.' || c == ',' )
                            {
                                uri = uri.substring(0,uri.length()-1);
                                buf = c + buf;
                            }
                            // System.out.println("URI match "+uri);
                            m_currentElement.addContent( prefix );
                            makeDirectURILink( uri );
                        }
                        else
                        {
                            // System.out.println("Matched: '"+camelCase+"'");
                            // System.out.println("Split to '"+firstPart+"', and '"+buf+"'");
                            // System.out.println("prefix="+prefix);
                            m_currentElement.addContent( prefix );

                            makeCamelCaseLink( camelCase );
                        }
                    }

                    m_currentElement.addContent( buf );
                }
                else
                {
                    //
                    //  No camelcase asked for, just add the elements
                    //
                    m_currentElement.addContent( buf );
                }
            }
            catch( IllegalDataException e )
            {
                //
                // Sometimes it's possible that illegal XML chars is added to the data.
                // Here we make sure it does not stop parsing.
                //
                m_currentElement.addContent( makeError(cleanupSuspectData( e.getMessage() )) );
            }
        }

        return numChars;
    }

    /**
     *  Escapes XML entities in a HTML-compatible way (i.e. does not escape
     *  entities that are already escaped).
     *
     *  @param buf
     *  @return An escaped string.
     */
    private String escapeHTMLEntities(String buf)
    {
        StringBuilder tmpBuf = new StringBuilder( buf.length() + 20 );

        for( int i = 0; i < buf.length(); i++ )
        {
            char ch = buf.charAt(i);

            if( ch == '<' )
            {
                tmpBuf.append("&lt;");
            }
            else if( ch == '>' )
            {
                tmpBuf.append("&gt;");
            }
            else if( ch == '\"' )
            {
                tmpBuf.append("&quot;");
            }
            else if( ch == '&' )
            {
                //
                //  If the following is an XML entity reference (&#.*;) we'll
                //  leave it as it is; otherwise we'll replace it with an &amp;
                //

                boolean isEntity = false;
                StringBuilder entityBuf = new StringBuilder();

                if( i < buf.length() -1 )
                {
                    for( int j = i; j < buf.length(); j++ )
                    {
                        char ch2 = buf.charAt(j);

                        if( Character.isLetterOrDigit( ch2 ) || (ch2 == '#' && j == i+1) || ch2 == ';' || ch2 == '&' )
                        {
                            entityBuf.append(ch2);

                            if( ch2 == ';' )
                            {
                                isEntity = true;
                                break;
                            }
                        }
                        else
                        {
                            break;
                        }
                    }
                }

                if( isEntity )
                {
                    tmpBuf.append( entityBuf );
                    i = i + entityBuf.length() - 1;
                }
                else
                {
                    tmpBuf.append("&amp;");
                }

            }
            else
            {
                tmpBuf.append( ch );
            }
        }

        return tmpBuf.toString();
    }

    private Element pushElement( Element e )
    {
        flushPlainText();
        m_currentElement.addContent( e );
        m_currentElement = e;

        return e;
    }

    private Element addElement( Content e )
    {
        if( e != null )
        {
            flushPlainText();
            m_currentElement.addContent( e );
        }
        return m_currentElement;
    }

    /**
     *  All elements that can be empty by the HTML DTD.
     */
    //  Keep sorted.
    private static final String[] EMPTY_ELEMENTS = {
        "area", "base", "br", "col", "hr", "img", "input", "link", "meta", "p", "param"
    };

    /**
     *  Goes through the current element stack and pops all elements until this
     *  element is found - this essentially "closes" and element.
     *
     *  @param s
     *  @return The new current element, or null, if there was no such element in the entire stack.
     */
    private Element popElement( String s )
    {
        int flushedBytes = flushPlainText();

        Element currEl = m_currentElement;

        while( currEl.getParentElement() != null )
        {
            if( currEl.getName().equals(s) && !currEl.isRootElement() )
            {
                m_currentElement = currEl.getParentElement();

                //
                //  Check if it's okay for this element to be empty.  Then we will
                //  trick the JDOM generator into not generating an empty element,
                //  by putting an empty string between the tags.  Yes, it's a kludge
                //  but what'cha gonna do about it. :-)
                //

                if( flushedBytes == 0 && Arrays.binarySearch( EMPTY_ELEMENTS, s ) < 0 )
                {
                    currEl.addContent("");
                }

                return m_currentElement;
            }

            currEl = currEl.getParentElement();
        }

        return null;
    }


    /**
     *  Reads the stream until it meets one of the specified
     *  ending characters, or stream end.  The ending character will be left
     *  in the stream.
     */
    private String readUntil( String endChars )
        throws IOException
    {
        StringBuilder sb = new StringBuilder( 80 );
        int ch = nextToken();

        while( ch != -1 )
        {
            if( ch == '\\' )
            {
                ch = nextToken();
                if( ch == -1 )
                {
                    break;
                }
            }
            else
            {
                if( endChars.indexOf((char)ch) != -1 )
                {
                    pushBack( ch );
                    break;
                }
            }
            sb.append( (char) ch );
            ch = nextToken();
        }

        return sb.toString();
    }

    /**
     *  Reads the stream while the characters that have been specified are
     *  in the stream, returning then the result as a String.
     */
    private String readWhile( String endChars )
        throws IOException
    {
        StringBuilder sb = new StringBuilder( 80 );
        int ch = nextToken();

        while( ch != -1 )
        {
            if( endChars.indexOf((char)ch) == -1 )
            {
                pushBack( ch );
                break;
            }

            sb.append( (char) ch );
            ch = nextToken();
        }

        return sb.toString();
    }

    private JSPWikiMarkupParser m_cleanTranslator;

    /**
     *  Does a lazy init.  Otherwise, we would get into a situation
     *  where HTMLRenderer would try and boot a TranslatorReader before
     *  the TranslatorReader it is contained by is up.
     */
    private JSPWikiMarkupParser getCleanTranslator()
    {
        if( m_cleanTranslator == null )
        {
            WikiContext dummyContext = new WikiContext( m_engine,
                                                        m_context.getHttpRequest(),
                                                        m_context.getPage() );
            m_cleanTranslator = new JSPWikiMarkupParser( dummyContext, null );

            m_cleanTranslator.m_allowHTML = true;
        }

        return m_cleanTranslator;
    }
    /**
     *  Modifies the "hd" parameter to contain proper values.  Because
     *  an "id" tag may only contain [a-zA-Z0-9:_-], we'll replace the
     *  % after url encoding with '_'.
     *  <p>
     *  Counts also duplicate headings (= headings with similar name), and
     *  attaches a counter.
     */
    private String makeHeadingAnchor( String baseName, String title, Heading hd )
    {
        hd.m_titleText = title;
        title = MarkupParser.wikifyLink( title );

        hd.m_titleSection = m_engine.encodeName(title);

        if( m_titleSectionCounter.containsKey( hd.m_titleSection ) )
        {
            Integer count = m_titleSectionCounter.get( hd.m_titleSection );
            count = count + 1;
            m_titleSectionCounter.put( hd.m_titleSection, count );
            hd.m_titleSection += "-" + count;
        }
        else
        {
            m_titleSectionCounter.put( hd.m_titleSection, 1 );
        }

        hd.m_titleAnchor = "section-"+m_engine.encodeName(baseName)+
                           "-"+hd.m_titleSection;
        hd.m_titleAnchor = hd.m_titleAnchor.replace( '%', '_' );
        hd.m_titleAnchor = hd.m_titleAnchor.replace( '/', '_' );

        return hd.m_titleAnchor;
    }

    private String makeSectionTitle( String title )
    {
        title = title.trim();
        String outTitle;

        try
        {
            JSPWikiMarkupParser dtr = getCleanTranslator();
            dtr.setInputReader( new StringReader(title) );

            CleanTextRenderer ctt = new CleanTextRenderer(m_context, dtr.parse());

            outTitle = ctt.getString();
        }
        catch( IOException e )
        {
            log.fatal("CleanTranslator not working", e);
            throw new InternalWikiException("CleanTranslator not working as expected, when cleaning title"+ e.getMessage() , e);
        }

        return outTitle;
    }

    /**
     *  Returns XHTML for the heading.
     *
     *  @param level The level of the heading.  @see Heading
     *  @param title the title for the heading
     *  @param hd a List to which heading should be added
     *  @return An Element containing the heading
     */
    public Element makeHeading( int level, String title, Heading hd )
    {
        Element el = null;

        String pageName = m_context.getPage().getName();

        String outTitle = makeSectionTitle( title );

        hd.m_level = level;

        switch( level )
        {
          case Heading.HEADING_SMALL:
            el = new Element("h4").setAttribute("id",makeHeadingAnchor( pageName, outTitle, hd ));
            break;

          case Heading.HEADING_MEDIUM:
            el = new Element("h3").setAttribute("id",makeHeadingAnchor( pageName, outTitle, hd ));
            break;

          case Heading.HEADING_LARGE:
            el = new Element("h2").setAttribute("id",makeHeadingAnchor( pageName, outTitle, hd ));
            break;

          default:
            throw new InternalWikiException("Illegal heading type "+level);
        }


        return el;
    }

    /**
     *  When given a link to a WikiName, we just return
     *  a proper HTML link for it.  The local link mutator
     *  chain is also called.
     */
    private Element makeCamelCaseLink( String wikiname )
    {
        String matchedLink = m_linkParsingOperations.linkIfExists( wikiname );

        callMutatorChain( m_localLinkMutatorChain, wikiname );

        if( matchedLink != null ) {
            makeLink( READ, matchedLink, wikiname, null, null );
        } else {
            makeLink( EDIT, wikiname, wikiname, null, null );
        }

        return m_currentElement;
    }

    /** Holds the image URL for the duration of this parser */
    private String m_outlinkImageURL = null;

    /**
     *  Returns an element for the external link image (out.png).  However,
     *  this method caches the URL for the lifetime of this MarkupParser,
     *  because it's commonly used, and we'll end up with possibly hundreds
     *  our thousands of references to it...  It's a lot faster, too.
     *
     *  @return  An element containing the HTML for the outlink image.
     */
    private Element outlinkImage()
    {
        Element el = null;

        if( m_useOutlinkImage )
        {
            if( m_outlinkImageURL == null )
            {
                m_outlinkImageURL = m_context.getURL( WikiContext.NONE, OUTLINK_IMAGE );
            }

            el = new Element( "img" ).setAttribute( "class", OUTLINK );
            el.setAttribute( "src", m_outlinkImageURL );
            el.setAttribute( "alt","" );
        }

        return el;
    }

    /**
     *  Takes an URL and turns it into a regular wiki link.  Unfortunately,
     *  because of the way that flushPlainText() works, it already encodes
     *  all of the XML entities.  But so does WikiContext.getURL(), so we
     *  have to do a reverse-replace here, so that it can again be replaced in makeLink.
     *  <p>
     *  What a crappy problem.
     *
     * @param url
     * @return An anchor Element containing the link.
     */
    private Element makeDirectURILink( String url )
    {
        Element result;
        String last = null;

        if( url.endsWith(",") || url.endsWith(".") )
        {
            last = url.substring( url.length()-1 );
            url  = url.substring( 0, url.length()-1 );
        }

        callMutatorChain( m_externalLinkMutatorChain, url );

        if( m_linkParsingOperations.isImageLink( url ) )
        {
            result = handleImageLink( StringUtils.replace(url,"&amp;","&"), url, false );
        }
        else
        {
            result = makeLink( EXTERNAL, StringUtils.replace(url,"&amp;","&"), url, null, null );
            addElement( outlinkImage() );
        }

        if( last != null )
        {
            m_plainTextBuf.append(last);
        }

        return result;
    }

    /**
     *  Image links are handled differently:
     *  1. If the text is a WikiName of an existing page,
     *     it gets linked.
     *  2. If the text is an external link, then it is inlined.
     *  3. Otherwise it becomes an ALT text.
     *
     *  @param reallink The link to the image.
     *  @param link     Link text portion, may be a link to somewhere else.
     *  @param hasLinkText If true, then the defined link had a link text available.
     *                  This means that the link text may be a link to a wiki page,
     *                  or an external resource.
     */

    // FIXME: isExternalLink() is called twice.
    private Element handleImageLink( String reallink, String link, boolean hasLinkText )
    {
        String possiblePage = MarkupParser.cleanLink( link );

        if( m_linkParsingOperations.isExternalLink( link ) && hasLinkText )
        {
            return makeLink( IMAGELINK, reallink, link, null, null );
        }
        else if( m_linkParsingOperations.linkExists( possiblePage ) && hasLinkText )
        {
            // System.out.println("Orig="+link+", Matched: "+matchedLink);
            callMutatorChain( m_localLinkMutatorChain, possiblePage );

            return makeLink( IMAGEWIKILINK, reallink, link, null, null );
        }
        else
        {
            return makeLink( IMAGE, reallink, link, null, null );
        }
    }

    private Element handleAccessRule( String ruleLine )
    {
        if( m_wysiwygEditorMode )
        {
            m_currentElement.addContent( "[" + ruleLine + "]" );
        }

        if( !m_parseAccessRules ) return m_currentElement;
        Acl acl;
        WikiPage          page = m_context.getRealPage();
        // UserDatabase      db = m_context.getEngine().getUserDatabase();

        if( ruleLine.startsWith( "{" ) )
            ruleLine = ruleLine.substring( 1 );
        if( ruleLine.endsWith( "}" ) )
            ruleLine = ruleLine.substring( 0, ruleLine.length() - 1 );

        if( log.isDebugEnabled() ) log.debug("page="+page.getName()+", ACL = "+ruleLine);

        try
        {
            acl = m_engine.getAclManager().parseAcl( page, ruleLine );

            page.setAcl( acl );

            if( log.isDebugEnabled() ) log.debug( acl.toString() );
        }
        catch( WikiSecurityException wse )
        {
            return makeError( wse.getMessage() );
        }

        return m_currentElement;
    }

    /**
     *  Handles metadata setting [{SET foo=bar}]
     */
    private Element handleMetadata( String link )
    {
        if( m_wysiwygEditorMode )
        {
            m_currentElement.addContent( "[" + link + "]" );
        }

        try
        {
            String args = link.substring( link.indexOf(' '), link.length()-1 );

            String name = args.substring( 0, args.indexOf('=') );
            String val  = args.substring( args.indexOf('=')+1, args.length() );

            name = name.trim();
            val  = val.trim();

            if( val.startsWith("'") ) val = val.substring( 1 );
            if( val.endsWith("'") )   val = val.substring( 0, val.length()-1 );

            // log.debug("SET name='"+name+"', value='"+val+"'.");

            if( name.length() > 0 && val.length() > 0 )
            {
                val = m_engine.getVariableManager().expandVariables( m_context,
                                                                     val );

                m_context.getPage().setAttribute( name, val );
            }
        }
        catch( Exception e )
        {
            ResourceBundle rb = Preferences.getBundle( m_context, InternationalizationManager.CORE_BUNDLE );
            return makeError( MessageFormat.format( rb.getString( "markupparser.error.invalidset" ), link ) );
        }

        return m_currentElement;
    }

    /**
     *  Emits a processing instruction that will disable markup escaping. This is
     *  very useful if you want to emit HTML directly into the stream.
     *
     */
    private void disableOutputEscaping()
    {
        addElement( new ProcessingInstruction(Result.PI_DISABLE_OUTPUT_ESCAPING, "") );
    }

    /**
     *  Gobbles up all hyperlinks that are encased in square brackets.
     */
    private Element handleHyperlinks( String linktext, int pos )
    {
        ResourceBundle rb = Preferences.getBundle( m_context, InternationalizationManager.CORE_BUNDLE );

        StringBuilder sb = new StringBuilder(linktext.length()+80);

        if( m_linkParsingOperations.isAccessRule( linktext ) )
        {
            return handleAccessRule( linktext );
        }

        if( m_linkParsingOperations.isMetadata( linktext ) )
        {
            return handleMetadata( linktext );
        }

        if( m_linkParsingOperations.isPluginLink( linktext ) )
        {
            try
            {
                PluginContent pluginContent = PluginContent.parsePluginLine( m_context, linktext, pos );
                //
                //  This might sometimes fail, especially if there is something which looks
                //  like a plugin invocation but is really not.
                //
                if( pluginContent != null )
                {
                    addElement( pluginContent );

                    pluginContent.executeParse( m_context );
                }
            }
            catch( PluginException e )
            {
                log.info( m_context.getRealPage().getWiki() + " : " + m_context.getRealPage().getName() + " - Failed to insert plugin: " + e.getMessage() );
                //log.info( "Root cause:",e.getRootThrowable() );
                if( !m_wysiwygEditorMode )
                {
                    ResourceBundle rbPlugin = Preferences.getBundle( m_context, WikiPlugin.CORE_PLUGINS_RESOURCEBUNDLE );
                    return addElement( makeError( MessageFormat.format( rbPlugin.getString( "plugin.error.insertionfailed" ),
                                                                        m_context.getRealPage().getWiki(),
                                                                        m_context.getRealPage().getName(),
                                                                        e.getMessage() ) ) );
                }
            }

            return m_currentElement;
        }

        try
        {
            LinkParser.Link link = m_linkParser.parse(linktext);
            linktext       = link.getText();
            String linkref = link.getReference();

            //
            //  Yes, we now have the components separated.
            //  linktext = the text the link should have
            //  linkref  = the url or page name.
            //
            //  In many cases these are the same.  [linktext|linkref].
            //
            if( m_linkParsingOperations.isVariableLink( linktext ) )
            {
                Content el = new VariableContent(linktext);

                addElement( el );
            }
            else if( m_linkParsingOperations.isExternalLink( linkref ) )
            {
                // It's an external link, out of this Wiki

                callMutatorChain( m_externalLinkMutatorChain, linkref );

                if( m_linkParsingOperations.isImageLink( linkref ) )
                {
                    handleImageLink( linkref, linktext, link.hasReference() );
                }
                else
                {
                    makeLink( EXTERNAL, linkref, linktext, null, link.getAttributes() );
                    addElement( outlinkImage() );
                }
            }
            else if( link.isInterwikiLink() )
            {
                // It's an interwiki link
                // InterWiki links also get added to external link chain
                // after the links have been resolved.

                // FIXME: There is an interesting issue here:  We probably should
                //        URLEncode the wikiPage, but we can't since some of the
                //        Wikis use slashes (/), which won't survive URLEncoding.
                //        Besides, we don't know which character set the other Wiki
                //        is using, so you'll have to write the entire name as it appears
                //        in the URL.  Bugger.

                String extWiki  = link.getExternalWiki();
                String wikiPage = link.getExternalWikiPage();

                if( m_wysiwygEditorMode )
                {
                    makeLink( INTERWIKI, extWiki + ":" + wikiPage, linktext, null, link.getAttributes() );
                }
                else
                {
                    String urlReference = m_engine.getInterWikiURL( extWiki );

                    if( urlReference != null )
                    {
                        urlReference = TextUtil.replaceString( urlReference, "%s", wikiPage );
                        urlReference = callMutatorChain( m_externalLinkMutatorChain, urlReference );

                        if( m_linkParsingOperations.isImageLink(urlReference) )
                        {
                            handleImageLink( urlReference, linktext, link.hasReference() );
                        }
                        else
                        {
                            makeLink( INTERWIKI, urlReference, linktext, null, link.getAttributes() );
                        }

                        if( m_linkParsingOperations.isExternalLink(urlReference) )
                        {
                            addElement( outlinkImage() );
                        }
                    }
                    else
                    {
                        Object[] args = { escapeHTMLEntities(extWiki) };

                        addElement( makeError( MessageFormat.format( rb.getString( "markupparser.error.nointerwikiref" ), args ) ) );
                    }
                }
            }
            else if( linkref.startsWith("#") )
            {
                // It defines a local footnote
                makeLink( LOCAL, linkref, linktext, null, link.getAttributes() );
            }
            else if( TextUtil.isNumber( linkref ) )
            {
                // It defines a reference to a local footnote
                makeLink( LOCALREF, linkref, linktext, null, link.getAttributes() );
            }
            else
            {
                int hashMark = -1;

                //
                //  Internal wiki link, but is it an attachment link?
                //
                String attachment = m_engine.getAttachmentManager().getAttachmentInfoName( m_context, linkref );
                if( attachment != null )
                {
                    callMutatorChain( m_attachmentLinkMutatorChain, attachment );

                    if( m_linkParsingOperations.isImageLink( linkref ) )
                    {
                        attachment = m_context.getURL( WikiContext.ATTACH, attachment );
                        sb.append( handleImageLink( attachment, linktext, link.hasReference() ) );
                    }
                    else
                    {
                        makeLink( ATTACHMENT, attachment, linktext, null, link.getAttributes() );
                    }
                }
                else if( (hashMark = linkref.indexOf('#')) != -1 )
                {
                    // It's an internal Wiki link, but to a named section

                    String namedSection = linkref.substring( hashMark+1 );
                    linkref = linkref.substring( 0, hashMark );

                    linkref = MarkupParser.cleanLink( linkref );

                    callMutatorChain( m_localLinkMutatorChain, linkref );

                    String matchedLink = m_linkParsingOperations.linkIfExists( linkref );
                    if( matchedLink != null ) {
                        String sectref = "section-"+m_engine.encodeName(matchedLink+"-"+wikifyLink(namedSection));
                        sectref = sectref.replace('%', '_');
                        makeLink( READ, matchedLink, linktext, sectref, link.getAttributes() );
                    } else {
                        makeLink( EDIT, linkref, linktext, null, link.getAttributes() );
                    }
                }
                else
                {
                    // It's an internal Wiki link
                    linkref = MarkupParser.cleanLink( linkref );

                    callMutatorChain( m_localLinkMutatorChain, linkref );

                    String matchedLink = m_linkParsingOperations.linkIfExists( linkref );
                    if( matchedLink != null ) {
                        makeLink( READ, matchedLink, linktext, null, link.getAttributes() );
                    } else {
                        makeLink( EDIT, linkref, linktext, null, link.getAttributes() );
                    }
                }
            }
        }
        catch( ParseException e )
        {
            log.info("Parser failure: ",e);
            Object[] args = { e.getMessage() };
            addElement( makeError( MessageFormat.format( rb.getString( "markupparser.error.parserfailure" ), args ) ) );
        }

        return m_currentElement;
    }

    /**
     *  Pushes back any string that has been read.  It will obviously
     *  be pushed back in a reverse order.
     *
     *  @since 2.1.77
     */
    private void pushBack( String s )
        throws IOException
    {
        for( int i = s.length()-1; i >= 0; i-- )
        {
            pushBack( s.charAt(i) );
        }
    }

    private Element handleBackslash()
        throws IOException
    {
        int ch = nextToken();

        if( ch == '\\' )
        {
            int ch2 = nextToken();

            if( ch2 == '\\' )
            {
                pushElement( new Element("br").setAttribute("clear","all"));
                return popElement("br");
            }

            pushBack( ch2 );

            pushElement( new Element("br") );
            return popElement("br");
        }

        pushBack( ch );

        return null;
    }

    private Element handleUnderscore()
        throws IOException
    {
        int ch = nextToken();
        Element el = null;

        if( ch == '_' )
        {
            if( m_isbold )
            {
                el = popElement("b");
            }
            else
            {
                el = pushElement( new Element("b") );
            }
            m_isbold = !m_isbold;
        }
        else
        {
            pushBack( ch );
        }

        return el;
    }


    /**
     *  For example: italics.
     */
    private Element handleApostrophe()
        throws IOException
    {
        int ch = nextToken();
        Element el = null;

        if( ch == '\'' )
        {
            if( m_isitalic )
            {
                el = popElement("i");
            }
            else
            {
                el = pushElement( new Element("i") );
            }
            m_isitalic = !m_isitalic;
        }
        else
        {
            pushBack( ch );
        }

        return el;
    }

    private Element handleOpenbrace( boolean isBlock )
        throws IOException
    {
        int ch = nextToken();

        if( ch == '{' )
        {
            int ch2 = nextToken();

            if( ch2 == '{' )
            {
                m_isPre = true;
                m_isEscaping = true;
                m_isPreBlock = isBlock;

                if( isBlock )
                {
                    startBlockLevel();
                    return pushElement( new Element("pre") );
                }

                return pushElement( new Element("span").setAttribute("class","inline-code") );
            }

            pushBack( ch2 );

            return pushElement( new Element("tt") );
        }

        pushBack( ch );

        return null;
    }

    /**
     *  Handles both }} and }}}
     */
    private Element handleClosebrace()
        throws IOException
    {
        int ch2 = nextToken();

        if( ch2 == '}' )
        {
            int ch3 = nextToken();

            if( ch3 == '}' )
            {
                if( m_isPre )
                {
                    if( m_isPreBlock )
                    {
                        popElement( "pre" );
                    }
                    else
                    {
                        popElement( "span" );
                    }

                    m_isPre = false;
                    m_isEscaping = false;
                    return m_currentElement;
                }

                m_plainTextBuf.append("}}}");
                return m_currentElement;
            }

            pushBack( ch3 );

            if( !m_isEscaping )
            {
                return popElement("tt");
            }
        }

        pushBack( ch2 );

        return null;
    }

    private Element handleDash()
        throws IOException
    {
        int ch = nextToken();

        if( ch == '-' )
        {
            int ch2 = nextToken();

            if( ch2 == '-' )
            {
                int ch3 = nextToken();

                if( ch3 == '-' )
                {
                    // Empty away all the rest of the dashes.
                    // Do not forget to return the first non-match back.
                    do
                    {
                        ch = nextToken();
                    }
                    while ( ch == '-' );

                    pushBack(ch);
                    startBlockLevel();
                    pushElement( new Element("hr") );
                    return popElement( "hr" );
                }

                pushBack( ch3 );
            }
            pushBack( ch2 );
        }

        pushBack( ch );

        return null;
    }

    private Element handleHeading()
        throws IOException
    {
        Element el = null;

        int ch  = nextToken();

        Heading hd = new Heading();

        if( ch == '!' )
        {
            int ch2 = nextToken();

            if( ch2 == '!' )
            {
                String title = peekAheadLine();

                el = makeHeading( Heading.HEADING_LARGE, title, hd);
            }
            else
            {
                pushBack( ch2 );
                String title = peekAheadLine();
                el = makeHeading( Heading.HEADING_MEDIUM, title, hd );
            }
        }
        else
        {
            pushBack( ch );
            String title = peekAheadLine();
            el = makeHeading( Heading.HEADING_SMALL, title, hd );
        }

        callHeadingListenerChain( hd );

        m_lastHeading = hd;

        if( el != null ) pushElement(el);

        return el;
    }

    /**
     *  Reads the stream until the next EOL or EOF.  Note that it will also read the
     *  EOL from the stream.
     */
    private StringBuilder readUntilEOL()
        throws IOException
    {
        int ch;
        StringBuilder buf = new StringBuilder( 256 );

        while( true )
        {
            ch = nextToken();

            if( ch == -1 )
                break;

            buf.append( (char) ch );

            if( ch == '\n' )
                break;
        }
        return buf;
    }

    /** Controls whether italic is restarted after a paragraph shift */

    private boolean m_restartitalic = false;
    private boolean m_restartbold   = false;

    private boolean m_newLine;

    /**
     *  Starts a block level element, therefore closing
     *  a potential open paragraph tag.
     */
    private void startBlockLevel()
    {
        // These may not continue over block level limits in XHTML

        popElement("i");
        popElement("b");
        popElement("tt");

        if( m_isOpenParagraph )
        {
            m_isOpenParagraph = false;
            popElement("p");
            m_plainTextBuf.append("\n"); // Just small beautification
        }

        m_restartitalic = m_isitalic;
        m_restartbold   = m_isbold;

        m_isitalic = false;
        m_isbold   = false;
    }

    private static String getListType( char c )
    {
        if( c == '*' )
        {
            return "ul";
        }
        else if( c == '#' )
        {
            return "ol";
        }
        throw new InternalWikiException("Parser got faulty list type: "+c);
    }
    /**
     *  Like original handleOrderedList() and handleUnorderedList()
     *  however handles both ordered ('#') and unordered ('*') mixed together.
     */

    // FIXME: Refactor this; it's a bit messy.

    private Element handleGeneralList()
        throws IOException
    {
         startBlockLevel();

         String strBullets = readWhile( "*#" );
         // String strBulletsRaw = strBullets;      // to know what was original before phpwiki style substitution
         int numBullets = strBullets.length();

         // override the beginning portion of bullet pattern to be like the previous
         // to simulate PHPWiki style lists

         if(m_allowPHPWikiStyleLists)
         {
             // only substitute if different
             if(!( strBullets.substring(0,Math.min(numBullets,m_genlistlevel)).equals
                   (m_genlistBulletBuffer.substring(0,Math.min(numBullets,m_genlistlevel)) ) ) )
             {
                 if(numBullets <= m_genlistlevel)
                 {
                     // Substitute all but the last character (keep the expressed bullet preference)
                     strBullets  = (numBullets > 1 ? m_genlistBulletBuffer.substring(0, numBullets-1) : "")
                                   + strBullets.substring(numBullets-1, numBullets);
                 }
                 else
                 {
                     strBullets = m_genlistBulletBuffer + strBullets.substring(m_genlistlevel, numBullets);
                 }
             }
         }

         //
         //  Check if this is still of the same type
         //
         if( strBullets.substring(0,Math.min(numBullets,m_genlistlevel)).equals
            (m_genlistBulletBuffer.substring(0,Math.min(numBullets,m_genlistlevel)) ) )
         {
             if( numBullets > m_genlistlevel )
             {
                 pushElement( new Element( getListType(strBullets.charAt(m_genlistlevel++) ) ) );

                 for( ; m_genlistlevel < numBullets; m_genlistlevel++ )
                 {
                     // bullets are growing, get from new bullet list
                     pushElement( new Element("li") );
                     pushElement( new Element( getListType(strBullets.charAt(m_genlistlevel)) ));
                 }
             }
             else if( numBullets < m_genlistlevel )
             {
                 //  Close the previous list item.
                 // buf.append( m_renderer.closeListItem() );
                 popElement( "li" );

                 for( ; m_genlistlevel > numBullets; m_genlistlevel-- )
                 {
                     // bullets are shrinking, get from old bullet list

                     popElement( getListType(m_genlistBulletBuffer.charAt(m_genlistlevel-1)) );
                     if( m_genlistlevel > 0 )
                     {
                         popElement( "li" );
                     }

                 }
             }
             else
             {
                 if( m_genlistlevel > 0 )
                 {
                     popElement( "li" );
                 }
             }
         }
         else
         {
             //
             //  The pattern has changed, unwind and restart
             //
             int  numEqualBullets;
             int  numCheckBullets;

             // find out how much is the same
             numEqualBullets = 0;
             numCheckBullets = Math.min(numBullets,m_genlistlevel);

             while( numEqualBullets < numCheckBullets )
             {
                 // if the bullets are equal so far, keep going
                 if( strBullets.charAt(numEqualBullets) == m_genlistBulletBuffer.charAt(numEqualBullets))
                     numEqualBullets++;
                 // otherwise giveup, we have found how many are equal
                 else
                     break;
             }

             //unwind
             for( ; m_genlistlevel > numEqualBullets; m_genlistlevel-- )
             {
                 popElement( getListType( m_genlistBulletBuffer.charAt(m_genlistlevel-1) ) );
                 if( m_genlistlevel > numBullets )
                 {
                     popElement("li");
                 }
             }

             //rewind

             pushElement( new Element(getListType( strBullets.charAt(numEqualBullets++) ) ) );
             for(int i = numEqualBullets; i < numBullets; i++)
             {
                 pushElement( new Element("li") );
                 pushElement( new Element( getListType( strBullets.charAt(i) ) ) );
             }
             m_genlistlevel = numBullets;
         }

         //
         //  Push a new list item, and eat away any extra whitespace
         //
         pushElement( new Element("li") );
         readWhile(" ");

         // work done, remember the new bullet list (in place of old one)
         m_genlistBulletBuffer.setLength(0);
         m_genlistBulletBuffer.append(strBullets);

         return m_currentElement;
    }

    private Element unwindGeneralList()
    {
        //unwind
        for( ; m_genlistlevel > 0; m_genlistlevel-- )
        {
            popElement( "li" );
            popElement( getListType(m_genlistBulletBuffer.charAt(m_genlistlevel-1)) );
        }

        m_genlistBulletBuffer.setLength(0);

        return null;
    }


    private Element handleDefinitionList()
        throws IOException
    {
        if( !m_isdefinition )
        {
            m_isdefinition = true;

            startBlockLevel();

            pushElement( new Element("dl") );
            return pushElement( new Element("dt") );
        }

        return null;
    }

    private Element handleOpenbracket()
        throws IOException
    {
        StringBuilder sb = new StringBuilder(40);
        int pos = getPosition();
        int ch = nextToken();
        boolean isPlugin = false;

        if( ch == '[' )
        {
            if( m_wysiwygEditorMode )
            {
                sb.append( '[' );
            }

            sb.append( (char)ch );

            while( (ch = nextToken()) == '[' )
            {
                sb.append( (char)ch );
            }
        }


        if( ch == '{' )
        {
            isPlugin = true;
        }

        pushBack( ch );

        if( sb.length() > 0 )
        {
            m_plainTextBuf.append( sb );
            return m_currentElement;
        }

        //
        //  Find end of hyperlink
        //

        ch = nextToken();
        int nesting = 1;    // Check for nested plugins

        while( ch != -1 )
        {
            int ch2 = nextToken(); pushBack(ch2);

            if( isPlugin )
            {
                if( ch == '[' && ch2 == '{' )
                {
                    nesting++;
                }
                else if( nesting == 0 && ch == ']' && sb.charAt(sb.length()-1) == '}' )
                {
                    break;
                }
                else if( ch == '}' && ch2 == ']' )
                {
                    // NB: This will be decremented once at the end
                    nesting--;
                }
            }
            else
            {
                if( ch == ']' )
                {
                    break;
                }
            }

            sb.append( (char) ch );

            ch = nextToken();
        }

        //
        //  If the link is never finished, do some tricks to display the rest of the line
        //  unchanged.
        //
        if( ch == -1 )
        {
            log.debug("Warning: unterminated link detected!");
            m_isEscaping = true;
            m_plainTextBuf.append( sb );
            flushPlainText();
            m_isEscaping = false;
            return m_currentElement;
        }

        return handleHyperlinks( sb.toString(), pos );
    }

    /**
     *  Reads the stream until the current brace is closed or stream end.
     */
    private String readBraceContent( char opening, char closing )
        throws IOException
    {
        StringBuilder sb = new StringBuilder(40);
        int braceLevel = 1;
        int ch;
        while(( ch = nextToken() ) != -1 )
        {
            if( ch == '\\' )
            {
                continue;
            }
            else if ( ch == opening )
            {
                braceLevel++;
            }
            else if ( ch == closing )
            {
                braceLevel--;
                if (braceLevel==0)
                {
                  break;
                }
            }
            sb.append( (char)ch );
        }
        return sb.toString();
    }


    /**
     *  Handles constructs of type %%(style) and %%class
     * @param newLine
     * @return An Element containing the div or span, depending on the situation.
     * @throws IOException
     */
    private Element handleDiv( boolean newLine )
        throws IOException
    {
        int ch = nextToken();
        Element el = null;

        if( ch == '%' )
        {
            String style = null;
            String clazz = null;

            ch = nextToken();

            //
            //  Style or class?
            //
            if( ch == '(' )
            {
                style = readBraceContent('(',')');
            }
            else if( Character.isLetter( (char) ch ) )
            {
                pushBack( ch );
                clazz = readUntil( "( \t\n\r" );
                //Note: ref.https://www.w3.org/TR/CSS21/syndata.html#characters
                //CSS Classnames can contain only the characters [a-zA-Z0-9] and
                //ISO 10646 characters U+00A0 and higher, plus the "-" and the "_".
                //They cannot start with a digit, two hyphens, or a hyphen followed by a digit.

                //(1) replace '.' by spaces, allowing multiple classnames on a div or span
                //(2) remove any invalid character
                if( clazz != null){

                    clazz = clazz.replace('.', ' ')
                                 .replaceAll("[^\\s-_\\w\\x200-\\x377]+","");

                }
                ch = nextToken();

                //check for %%class1.class2( style information )
                if( ch == '(' )
                {
                    style = readBraceContent('(',')');
                }
                //
                //  Pop out only spaces, so that the upcoming EOL check does not check the
                //  next line.
                //
                else if( ch == '\n' || ch == '\r' )
                {
                    pushBack(ch);
                }
            }
            else
            {
                //
                // Anything else stops.
                //

                pushBack(ch);

                try
                {
                    Boolean isSpan = m_styleStack.pop();

                    if( isSpan == null )
                    {
                        // Fail quietly
                    }
                    else if( isSpan.booleanValue() )
                    {
                        el = popElement( "span" );
                    }
                    else
                    {
                        el = popElement( "div" );
                    }
                }
                catch( EmptyStackException e )
                {
                    log.debug("Page '"+m_context.getName()+"' closes a %%-block that has not been opened.");
                    return m_currentElement;
                }

                return el;
            }

            //
            //  Check if there is an attempt to do something nasty
            //

            try
            {
                style = StringEscapeUtils.unescapeHtml(style);
                if( style != null && style.indexOf("javascript:") != -1 )
                {
                    log.debug("Attempt to output javascript within CSS:"+style);
                    ResourceBundle rb = Preferences.getBundle( m_context, InternationalizationManager.CORE_BUNDLE );
                    return addElement( makeError( rb.getString( "markupparser.error.javascriptattempt" ) ) );
                }
            }
            catch( NumberFormatException e )
            {
                //
                //  If there are unknown entities, we don't want the parser to stop.
                //
                ResourceBundle rb = Preferences.getBundle( m_context, InternationalizationManager.CORE_BUNDLE );
                String msg = MessageFormat.format( rb.getString( "markupparser.error.parserfailure"), e.getMessage() );
                return addElement( makeError( msg ) );
            }

            //
            //  Decide if we should open a div or a span?
            //
            String eol = peekAheadLine();

            if( eol.trim().length() > 0 )
            {
                // There is stuff after the class

                el = new Element("span");

                m_styleStack.push( Boolean.TRUE );
            }
            else
            {
                startBlockLevel();
                el = new Element("div");
                m_styleStack.push( Boolean.FALSE );
            }

            if( style != null ) el.setAttribute("style", style);
            if( clazz != null ) el.setAttribute("class", clazz);
            el = pushElement( el );

            return el;
        }

        pushBack(ch);

        return el;
    }

    private Element handleSlash( boolean newLine )
        throws IOException
    {
        int ch = nextToken();

        pushBack(ch);
        if( ch == '%' && !m_styleStack.isEmpty() )
        {
            return handleDiv( newLine );
        }

        return null;
    }

    private Element handleBar( boolean newLine )
        throws IOException
    {
        Element el = null;

        if( !m_istable && !newLine )
        {
            return null;
        }

        //
        //  If the bar is in the first column, we will either start
        //  a new table or continue the old one.
        //

        if( newLine )
        {
            if( !m_istable )
            {
                startBlockLevel();
                el = pushElement( new Element("table").setAttribute("class","wikitable").setAttribute("border","1") );
                m_istable = true;
                m_rowNum = 0;
            }

            m_rowNum++;
            Element tr = ( m_rowNum % 2 != 0 )
                       ? new Element("tr").setAttribute("class", "odd")
                       : new Element("tr");
            el = pushElement( tr );
        }

        //
        //  Check out which table cell element to start;
        //  a header element (th) or a regular element (td).
        //
        int ch = nextToken();

        if( ch == '|' )
        {
            if( !newLine )
            {
                el = popElement("th");
                if( el == null ) popElement("td");
            }
            el = pushElement( new Element("th") );
        }
        else
        {
            if( !newLine )
            {
                el = popElement("td");
                if( el == null ) popElement("th");
            }

            el = pushElement( new Element("td") );

            pushBack( ch );
        }

        return el;
    }

    /**
     *  Generic escape of next character or entity.
     */
    private Element handleTilde()
        throws IOException
    {
        int ch = nextToken();

        if( ch == ' ' )
        {
            if( m_wysiwygEditorMode )
            {
                m_plainTextBuf.append( "~ " );
            }
            return m_currentElement;
        }

        if( ch == '|' || ch == '~' || ch == '\\' || ch == '*' || ch == '#' ||
            ch == '-' || ch == '!' || ch == '\'' || ch == '_' || ch == '[' ||
            ch == '{' || ch == ']' || ch == '}' || ch == '%' )
        {
            if( m_wysiwygEditorMode )
            {
                m_plainTextBuf.append( '~' );
            }

            m_plainTextBuf.append( (char)ch );
            m_plainTextBuf.append(readWhile( ""+(char)ch ));
            return m_currentElement;
        }

        // No escape.
        pushBack( ch );

        return null;
    }

    private void fillBuffer( Element startElement )
        throws IOException
    {
        m_currentElement = startElement;

        boolean quitReading = false;
        m_newLine = true;
        disableOutputEscaping();

        while(!quitReading)
        {
            int ch = nextToken();

            if( ch == -1 ) break;

            //
            //  Check if we're actually ending the preformatted mode.
            //  We still must do an entity transformation here.
            //
            if( m_isEscaping )
            {
                if( ch == '}' )
                {
                    if( handleClosebrace() == null ) m_plainTextBuf.append( (char) ch );
                }
                else if( ch == -1 )
                {
                    quitReading = true;
                }
                else if( ch == '\r' )
                {
                    // DOS line feeds we ignore.
                }
                else if( ch == '<' )
                {
                    m_plainTextBuf.append( "&lt;" );
                }
                else if( ch == '>' )
                {
                    m_plainTextBuf.append( "&gt;" );
                }
                else if( ch == '&' )
                {
                    m_plainTextBuf.append( "&amp;" );
                }
                else if( ch == '~' )
                {
                    String braces = readWhile("}");
                    if( braces.length() >= 3 )
                    {
                        m_plainTextBuf.append("}}}");

                        braces = braces.substring(3);
                    }
                    else
                    {
                        m_plainTextBuf.append( (char) ch );
                    }

                    for( int i = braces.length()-1; i >= 0; i-- )
                    {
                        pushBack(braces.charAt(i));
                    }
                }
                else
                {
                    m_plainTextBuf.append( (char) ch );
                }

                continue;
            }

            //
            //  An empty line stops a list
            //
            if( m_newLine && ch != '*' && ch != '#' && ch != ' ' && m_genlistlevel > 0 )
            {
                m_plainTextBuf.append(unwindGeneralList());
            }

            if( m_newLine && ch != '|' && m_istable )
            {
                popElement("table");
                m_istable = false;
            }

            int skip = IGNORE;

            //
            //  Do the actual parsing and catch any errors.
            //
            try
            {
                skip = parseToken( ch );
            }
            catch( IllegalDataException e )
            {
                log.info("Page "+m_context.getPage().getName()+" contains data which cannot be added to DOM tree: "+e.getMessage());

                makeError("Error: "+cleanupSuspectData(e.getMessage()) );
            }

            //
            //   The idea is as follows:  If the handler method returns
            //   an element (el != null), it is assumed that it has been
            //   added in the stack.  Otherwise the character is added
            //   as is to the plaintext buffer.
            //
            //   For the transition phase, if s != null, it also gets
            //   added in the plaintext buffer.
            //

            switch( skip )
            {
                case ELEMENT:
                    m_newLine = false;
                    break;

                case CHARACTER:
                    m_plainTextBuf.append( (char) ch );
                    m_newLine = false;
                    break;

                case IGNORE:
                default:
                    break;
            }
        }

        closeHeadings();
        popElement("domroot");
    }

    private String cleanupSuspectData( String s )
    {
        StringBuilder sb = new StringBuilder( s.length() );

        for( int i = 0; i < s.length(); i++ )
        {
            char c = s.charAt(i);

            if( Verifier.isXMLCharacter( c ) ) sb.append( c );
            else sb.append( "0x"+Integer.toString(c,16).toUpperCase() );
        }

        return sb.toString();
    }

    /** The token is a plain character. */
    protected static final int CHARACTER = 0;

    /** The token is a wikimarkup element. */
    protected static final int ELEMENT   = 1;

    /** The token is to be ignored. */
    protected static final int IGNORE    = 2;

    /**
     *  Return CHARACTER, if you think this was a plain character; ELEMENT, if
     *  you think this was a wiki markup element, and IGNORE, if you think
     *  we should ignore this altogether.
     *  <p>
     *  To add your own MarkupParser, you can override this method, but it
     *  is recommended that you call super.parseToken() as well to gain advantage
     *  of JSPWiki's own markup.  You can call it at the start of your own
     *  parseToken() or end - it does not matter.
     *
     * @param ch The character under investigation
     * @return {@link #ELEMENT}, {@link #CHARACTER} or {@link #IGNORE}.
     * @throws IOException If parsing fails.
     */
    protected int parseToken( int ch )
        throws IOException
    {
        Element el = null;

        //
        //  Now, check the incoming token.
        //
        switch( ch )
        {
          case '\r':
            // DOS linefeeds we forget
            return IGNORE;

          case '\n':
            //
            //  Close things like headings, etc.
            //

            // FIXME: This is not really very fast

            closeHeadings();

            popElement("dl"); // Close definition lists.
            if( m_istable )
            {
                popElement("tr");
            }

            m_isdefinition = false;

            if( m_newLine )
            {
                // Paragraph change.
                startBlockLevel();

                //
                //  Figure out which elements cannot be enclosed inside
                //  a <p></p> pair according to XHTML rules.
                //
                String nextLine = peekAheadLine();
                if( nextLine.length() == 0 ||
                    (nextLine.length() > 0 &&
                     !nextLine.startsWith("{{{") &&
                     !nextLine.startsWith("----") &&
                     !nextLine.startsWith("%%") &&
                     "*#!;".indexOf( nextLine.charAt(0) ) == -1) )
                {
                    pushElement( new Element("p") );
                    m_isOpenParagraph = true;

                    if( m_restartitalic )
                    {
                        pushElement( new Element("i") );
                        m_isitalic = true;
                        m_restartitalic = false;
                    }
                    if( m_restartbold )
                    {
                        pushElement( new Element("b") );
                        m_isbold = true;
                        m_restartbold = false;
                    }
                }
            }
            else
            {
                m_plainTextBuf.append("\n");
                m_newLine = true;
            }
            return IGNORE;


          case '\\':
            el = handleBackslash();
            break;

          case '_':
            el = handleUnderscore();
            break;

          case '\'':
            el = handleApostrophe();
            break;

          case '{':
            el = handleOpenbrace( m_newLine );
            break;

          case '}':
            el = handleClosebrace();
            break;

          case '-':
            if( m_newLine )
                el = handleDash();

            break;

          case '!':
            if( m_newLine )
            {
                el = handleHeading();
            }
            break;

          case ';':
            if( m_newLine )
            {
                el = handleDefinitionList();
            }
            break;

          case ':':
            if( m_isdefinition )
            {
                popElement("dt");
                el = pushElement( new Element("dd") );
                m_isdefinition = false;
            }
            break;

          case '[':
            el = handleOpenbracket();
            break;

          case '*':
            if( m_newLine )
            {
                pushBack('*');
                el = handleGeneralList();
            }
            break;

          case '#':
            if( m_newLine )
            {
                pushBack('#');
                el = handleGeneralList();
            }
            break;

          case '|':
            el = handleBar( m_newLine );
            break;

          case '~':
            el = handleTilde();
            break;

          case '%':
            el = handleDiv( m_newLine );
            break;

          case '/':
            el = handleSlash( m_newLine );
            break;

          default:
            break;
        }

        return el != null ? ELEMENT : CHARACTER;
    }

    private void closeHeadings()
    {
        if( m_lastHeading != null && !m_wysiwygEditorMode )
        {
            // Add the hash anchor element at the end of the heading
            addElement( new Element("a").setAttribute( "class",HASHLINK ).setAttribute( "href","#"+m_lastHeading.m_titleAnchor ).setText( "#" ) );
            m_lastHeading = null;
        }
        popElement("h2");
        popElement("h3");
        popElement("h4");
    }

    /**
     *  Parses the entire document from the Reader given in the constructor or
     *  set by {@link #setInputReader(Reader)}.
     *
     *  @return A WikiDocument, ready to be passed to the renderer.
     *  @throws IOException If parsing cannot be accomplished.
     */
    @Override
    public WikiDocument parse()
        throws IOException
    {
        WikiDocument d = new WikiDocument( m_context.getPage() );
        d.setContext( m_context );

        Element rootElement = new Element("domroot");

        d.setRootElement( rootElement );

        fillBuffer( rootElement );

        paragraphify(rootElement);

        return d;
    }

    /**
     *  Checks out that the first paragraph is correctly installed.
     *
     *  @param rootElement
     */
    private void paragraphify(Element rootElement)
    {
        //
        //  Add the paragraph tag to the first paragraph
        //
        List< Content > kids = rootElement.getContent();

        if( rootElement.getChild("p") != null )
        {
            ArrayList<Content> ls = new ArrayList<>();
            int idxOfFirstContent = 0;
            int count = 0;

            for( Iterator< Content > i = kids.iterator(); i.hasNext(); count++ )
            {
                Content c = i.next();
                if( c instanceof Element )
                {
                    String name = ( ( Element )c ).getName();
                    if( isBlockLevel( name ) ) break;
                }

                if( !(c instanceof ProcessingInstruction) )
                {
                    ls.add( c );
                    if( idxOfFirstContent == 0 ) idxOfFirstContent = count;
                }
            }

            //
            //  If there were any elements, then add a new <p> (unless it would
            //  be an empty one)
            //
            if( ls.size() > 0 )
            {
                Element newel = new Element("p");

                for( Iterator< Content > i = ls.iterator(); i.hasNext(); )
                {
                    Content c = i.next();

                    c.detach();
                    newel.addContent(c);
                }

                //
                // Make sure there are no empty <p/> tags added.
                //
                if( newel.getTextTrim().length() > 0 || !newel.getChildren().isEmpty() )
                    rootElement.addContent(idxOfFirstContent, newel);
            }
        }
    }

}