/**
 * Combined Wiki (MediaWiki) and HTML tokenizer based on pegjs. Emits several
 * chunks of tokens (one chunk per top-level block matched) and eventually an
 * end event. Tokens map to HTML tags as far as possible, with custom tokens
 * used where further processing on the token stream is needed.
 *
 * @author Gabriel Wicke <gwicke@wikimedia.org>
 * @author Brion Vibber <brion@wikimedia.org>
 */
{
    /* Fixme: use static functions to separate module! Unfortunately, this
     * does not work:
     * var tu = require('./mediawiki.tokenizer.utils.js');
     * console.warn(tu.flatten([]));
     * Using exports in the module gets a bit further, but accesses to
     * tu.flatten in productions still fail. Thus, I just moved the functions
     * here until a solution is found:
     */

    /* Static utilities */

    // Flatten a list of lists.
    //var simple_flatten = function ( e ) {
    //    // Fast single-level flatten:
    //    //return [].concat.apply([], e);
    //    
    //    var es = [];
    //    // flatten sub-arrays
    //    for(var i = 0, length = e.length; i < length; i++) {
    //        var ei = e[i];
    //        if ($.isArray(ei))
    //            es = es.concat(flatten(ei));
    //        else
    //            es.push(ei);
    //    };
    //    return es;
    //};

    var flatten = function ( e ) {
        // Fast single-level flatten:
        //return [].concat.apply([], e);
        
        var es = [];
        // flatten sub-arrays
        var chunkStart = null,
            modified = false;
        for(var i = 0, l = e.length; i < l; i++) {
            if ( e[i].constructor === Array ) {
                if ( chunkStart !== null ) {
                    es = es.concat( e.slice( chunkStart, i ), flatten( e[i] ) );
                    chunkStart = null;
                } else {
                    es = es.concat(flatten(e[i]));
                }
                modified = true;
            } else if ( chunkStart === null ) {
                chunkStart = i;
            }
        };
        if ( modified ) {
            if ( chunkStart !== null ) {
                es = es.concat( e.slice( chunkStart, e.length ) );
            }
            return es;
        } else {
            return e;
        }
    };

    
    var flatten_string = function ( c ) {
        var out = flatten_stringlist( c );
        if ( out.length === 1 && out[0].constructor === String ) {
            return out[0];
        } else {
            return out;
        }
    };

    var flatten_stringlist = function ( c ) {
        var out = [],
            text = '';
        c = flatten(c);
        for (var i = 0, l = c.length; i < l; i++) {
            var ci = c[i];
            if (ci.constructor === String) {
                if(ci !== '') {
                    text += ci;
                }
            } else {
                if (text !== '') {
                    out.push( text );
                    text = '';
                }
                out.push(ci);
            }
        }
        if (text !== '' ) {
            out.push( text );
        }
        return out;
    }

    // Remove escaped quotes from attributes etc
    // This was in the original PEG parser, but could not find anything in
    // MediaWiki that supports \' and \"-style escaping. So remove? -- gwicke
    var unquote = function (quotec, text) {
        return text.replace('\\' + quotec, quotec);
    };

    // Decode html entities. In a browser, this should only be fed the entity,
    // not untrusted html! XXX: replace with safer version.
    var unentity = function ( entity ) {
        return $("<div/>").html(entity).text();
    };

    // Debug print with global switch
    var dp = function ( msg ) {
        if ( false ) {
            console.warn(msg);
        }
    };

    var pp = function ( s ) { return JSON.stringify(s, null, 2); }

    /* 
     * Annotate a token stream with list items with appropriate list tokens
     *
     * XXX: Move this to a token handler in phase sync23! That way we can
     * support list items from templates too.
     *
     * @static
     * @method
     * @param {[tokens]}   Token stream with li tokens 
     * @returns {[tokens]} Token stream, possibly with additional list tokens
     * */
    var annotateList = function ( tokens ) {
        var out = [],    // List of tokens
            bstack = [], // Bullet stack, previous element's listStyle
            bnext = [],  // Next element's listStyle
            endtags = [];  // Stack of end tags

        var commonPrefixLength = function (x, y) {
            var minLength = Math.min(x.length, y.length);
            for(var i = 0; i < minLength; i++) {
                if (x[i] != y[i])
                    break;
            }
            return i;
        };

        var pushList = function ( listName, itemName ) {
            out.push( new TagTk( listName ));
            out.push( new TagTk( itemName ));
            endtags.push( new EndTagTk( listName ));
            endtags.push( new EndTagTk( itemName ));
        };

        var popTags = function ( n ) {
            for(;n > 0; n--) {
                // push list item..
                out.push(endtags.pop());
                // and the list end tag
                out.push(endtags.pop());
            }
        };

        var isDlDd = function (a, b) {
            var ab = [a,b].sort();
            return (ab[0] === ':' && ab[1] === ';');
        };

        var doListItem = function ( bs, bn ) {
            var prefixLen = commonPrefixLength (bs, bn);
            var changeLen = Math.max(bs.length, bn.length) - prefixLen;
            var prefix = bn.slice(0, prefixLen);
            // emit close tag tokens for closed lists
            if (changeLen === 0) {
                var itemToken = endtags.pop();
                out.push(itemToken);
                out.push(new TagTk( itemToken.name ));
                endtags.push(new EndTagTk( itemToken.name ));
            } else if ( bs.length == bn.length
                    && changeLen == 1
                    && isDlDd( bs[prefixLen], bn[prefixLen] ) ) {
                        // handle dd/dt transitions
                        out.push(endtags.pop());
                        if( bn[prefixLen] == ';') {
                            var newName = 'dt';
                        } else {
                            var newName = 'dd';
                        }
                        out.push(new TagTk( newName ));
                        endtags.push(new EndTagTk( newName ));
            } else {
                popTags(bs.length - prefixLen);

                if (prefixLen > 0 && bn.length == prefixLen ) {
                    var itemToken = endtags.pop();
                    out.push(itemToken);
                    out.push(new TagTk( itemToken.name ));
                    endtags.push(new EndTagTk( itemToken.name ));
                }

                for(var i = prefixLen; i < bn.length; i++) {
                    switch (bn[i]) {
                        case '*':
                            pushList('ul', 'li');
                            break;
                        case '#':
                            pushList('ol', 'li');
                            break;
                        case ';':
                            pushList('dl', 'dt');
                            break;
                        case ':':
                            pushList('dl', 'dd');
                            break;
                        default:
                            throw("Unknown node prefix " + prefix[i]);
                    }
                }
            }
        };

        for (var i = 0, length = tokens.length; i < length; i++) {
            var token = tokens[i];
            switch ( token.constructor ) {
                case TagTk:
                    switch (token.name) {
                        case 'list':
                            // ignore token
                            break;
                        case 'listItem':
                            // convert listItem to list and list item tokens
                            bnext = token.bullets;
                            doListItem( bstack, bnext );
                            bstack = bnext;
                            break;
                        default:
                            // pass through all remaining start tags
                            out.push(token);
                            break;
                    }
                    break;
                case EndTagTk:
                    if ( token.name == 'list' ) {
                        // pop all open list item tokens
                        popTags(bstack.length);
                        bstack = [];
                    } else {
                        out.push(token);
                    }
                    break;
                default:
                    out.push(token);
                    break;
            }
        }
        return out;
    };


    /* End static utilities */

    /*
     * Flags for specific parse environments (inside tables, links etc). Flags
     * trigger syntactic stops in the inline_breaks production, which
     * terminates inline and attribute matches. Flags merely reduce the number
     * of productions needed: The grammar is still context-free as the
     * productions can just be unrolled for all combinations of environments
     * at the cost of a much larger grammar.
     */
    var syntaxFlags = {};
    var setFlag = function(flag) {
        if (syntaxFlags[flag] !== undefined) {
            syntaxFlags[flag]++;
        } else {
            syntaxFlags[flag] = 1;
        }
        return true;
    };
    var clearFlag = function(flag) {
        syntaxFlags[flag]--;
        return false;
    };

    // Start position of top-level block
    // Could also provide positions for lower-level blocks using a stack.
    var blockStart = 0;

    // Start position of generic tag production
    var tagStartPos = 0;

    // cache the input length
    var inputLength = input.length;

    // pseudo-production that matches at end of input
    var isEOF = function (pos) {
        return pos === inputLength;
    };

    // text start position
    var textStart = 0;

    // hack to support numbered external links ([http://example.com]).
    // XXX: Move to token stream transform after templates are expanded!
    var linkCount = 1;

    // Define block-level tags in JS, so we can use toLowerCase to match tags
    // case-independently. This would be quite ugly (and possibly slower) if
    // done manually in the grammar.
    var block_names = (function () {
        var names = [ "p", "table", "td", "tr", "ul", "ol"
                    , "li", "dl", "dt", "dd", "div", "center"
                    , "blockquote" ];
        var bnames = {};
        for(var i = 0, l = names.length; i < l; i++) {
            bnames[names[i]] = true;
        }
        return bnames;
    })();

    var self = this;

        
}

/*********************************************************
 * The top-level production
 *********************************************************/

start
  = e:toplevelblock* newline* { 
      // end is passed inline as a token, as well as a separate event for now.
      
      // this does not work yet.
      //console.warn('about to emit' + pp(self));
	  //self._tokenizer.emit('chunk', [ { type: 'END' } ] );
      //self._tokenizer.emit('end');
		// Append the end (for obvious reasons this should not
		// be part of a stream, only when tokenizing complete
		// texts)
      //console.warn( pp( flatten ( e ) ) );
      cache = {};
      __parseArgs[2]( [ new EOFTk( ) ] );
      return []; //flatten(e);
  }


/*
 * A document (start production) is a sequence of toplevelblocks. Tokens are
 * emitted in chunks per toplevelblock to avoid buffering the full document.
 */
toplevelblock 
  = & { blockStart = pos; return true; } b:block {
    b = flatten(b);

    // Add source offsets for round-tripping. XXX: Add these not just for
    // toplevelblocks!
    if ( b.length ) {
        var bs = b[0];
        if ( bs.constructor === String && bs.attribs === undefined ) {
            b[0] = new String( bs );
            bs = b[0];
        }
        if (bs.dataAttribs === undefined) {
            bs.dataAttribs = {};
        }
        bs.dataAttribs.sourcePos = [blockStart, pos];
    }

    // Emit tokens for this toplevelblock. This feeds a chunk to the parser
    // pipeline.
    __parseArgs[2]( flatten( b ) );

    // We don't return any tokens to the start production to save memory. We
    // just emitted them already to our consumers.
    return true;
  }

/*
 * The actual contents of each block.
 */
block
  =   block_lines
    / & '<' r:( pre // tag variant can start anywhere
            / comment &eolf
            / nowiki
            // avoid a paragraph if we know that the line starts with a block tag
            / bt:block_tag { return [bt] } 
            ) { return r; }
    / para
    // Inlineline includes generic tags; wrapped into paragraphs in token
    // transform and DOM postprocessor
    / inlineline 
    / sol

/*
 * A block nested in other constructs. Avoid eating end delimiters for other
 * constructs by checking against inline_breaks first.
 */
nested_block = !inline_breaks b:block { return b }

/*
 * Line-based block constructs.
 */
block_lines
  = s:sol 
    // eat an empty line before the block
    s2:(os:optionalSpaceToken so:sol { return os.concat(so) })? 
    bl:block_line { 
        var s2_ = (s2 !== '') ? s2 : [];
        return s.concat(s2_, bl); 
    }

/*
 * Block structures with start-of-line wiki syntax
 */
block_line
  = h
  / & [{}|] tl:table_lines { return tl; }
  / lists
  // tag-only lines should not trigger pre
  / st:optionalSpaceToken
    bt:(bts:block_tag stl:optionalSpaceToken { return bts.concat(stl) })+ 
    &eolf { 
        return st.concat(bt); 
    }
  / pre_indent
  / pre


/*
 * A paragraph. We don't emit 'p' tokens to avoid issues with template
 * transclusions, <p> tags in the source and the like. Instead, we perform
 * some paragraph wrapping on the DOM.
 */
para
  = s1:sol s2:sol c:inlineline { 
      return s1.concat(s2, /* [new TagTk('p')],*/ c); 
  }

br = space* &newline { return new SelfclosingTagTk( 'br' ) }

/*
 * Syntax stops: Avoid eating significant tokens for higher-level productions
 * in nested inline productions.
 *
 * Repeated testing of flags is not terribly efficient. See new and faster
 * version below.
 */

/*
 * Syntax stops: Avoid eating significant tokens for higher-level productions
 * in nested inline productions.
 */
inline_breaks
  = & [=|!}:\r\n\]<]
    & { // Important hack: disable caching for this production, as the default
        // cache key does not take into account flag states!
        cacheKey = ''; 
        //console.warn('ilbf: ' + input.substr(pos, 5) );
        return null !== __parseArgs[3].inline_breaks( input, pos, syntaxFlags )
      } 

inline
  = c:(urltext / (! inline_breaks (inline_element / . )))+ {
      //console.warn('inline out:' + pp(out));
      return flatten_stringlist( c );
}


inlineline
  = c:(urltext / !inline_breaks (inline_element / [^\n]))+ {
      return flatten_stringlist( c );
}

inline_element
  = //& { dp('inline_element enter' + input.substr(pos, 10)); return true; }
      & '<' ( comment / xmlish_tag )
    /// & '{' ( & '{{{{{' template / tplarg / template )
    / & '{' tplarg_or_template 
    /// & '{' ( tplarg / template )
     // Eat three opening brackets as text.
    / '[[[' { return '[[[' }
    / & '[' ( wikilink / extlink )
    / & "'" quote

/* Headings  */

h = & "=" // guard, to make sure '='+ will match. 
          // XXX: Also check to end to avoid inline parsing?
    r:(
     s:'='+ // moved in here to make s accessible to inner action
     & { return setFlag('h'); }
     c:inlineline 
     e:'='+ 
     spc:(sp:space+ { return sp.join('') } / comment)*
     &eolf 
     {
        clearFlag('h');
        var level = Math.min(s.length, e.length);
        // convert surplus equals into text
        if(s.length > level) {
            var extras = s.substr(0, s.length - level);
            if(c[0].constructor === String) {
                c[0] = extras + c[0];
            } else {
                c.unshift( extras );
            }
        }
        if(e.length > level) {
            var extras = e.substr(0, e.length - level),
                lastElem = c[c.length - 1];
            if(lastElem.constructor === String) {
                lastElem += extras;
            } else {
                c.push( extras );
            }
        }

        return [new TagTk( 'h' + level )]
                .concat(c, [new EndTagTk( 'h' + level ), spc]);
      }
    / & { /* dp('nomatch exit h'); */ clearFlag('h'); return false } { return null }
    ) { return r }

comment
  = '<!--' c:comment_chars* ('-->' / eof)
    cs:(space* newline space* cn:comment { return cn })* {
        return [{ type: 'COMMENT', value: c.join('') }].concat(cs);
    }

comment_chars
  = c:[^-] { return c; }
  / c:'-' !'->' { return c; }



/**************************************************************
 * External (bracketed and autolinked) links
 **************************************************************/

urllink
  = ! { return syntaxFlags['extlink'] }
    target:url {
      return [ new TagTk( 'a', [new KV('href', target)] )
             , target
             , new EndTagTk( 'a' )
             ];
  }

extlink
  = ! { return syntaxFlags['extlink'] } // extlink cannot be nested
    (
        "[" 
        & { return setFlag('extlink'); }
        //target:urllink
        target:extlink_preprocessor_text
        text:(( space / [\u00A0\u1680\u180E\u2000-\u200A\u202F\u205F\u3000] )* 
              t:inlineline { return t } )?
        "]" {
            clearFlag('extlink');
            if ( text === '' ) {
                // XXX: Link numbering should be implemented in post-processor.
                text = [ "[" + linkCount + "]" ];
                linkCount++;
            }
            var res = [ 
                new TagTk( 'a', [
                            new KV('href', target),
                            new KV('data-mw-type', 'external')
                        ] ),
            ].concat( text 
                    , [ new EndTagTk( 'a' )]);
            //console.warn( JSON.stringify( res, null, 2 ) );
            return res;
        }
      / "[" & { clearFlag('extlink'); return false; }
    )

/* Defaul URL protocols in MediaWiki (see DefaultSettings). Normally these can
 * be configured dynamically. */

url_chars = [/fghimnstw]

url_protocol
  = '//' // for protocol-relative URLs
  / 'ftp://'
  / 'git://'
  / 'gopher://'
  / 'http://'
  / 'https://'
  / 'irc://'
  / 'ircs://'  // @bug 28503
  / 'mailto:'
  / 'mms://'
  / 'news:'
  / 'nntp://' // @bug 3808 RFC 1738
  / 'svn://'
  / 'telnet://' // Well if we're going to support the above.. -ævar
  / 'worldwind://'

// javascript does not support unicode features..
unicode_separator_space = [ \u00A0\u1680\u180E\u2000-\u200A\u202F\u205F\u3000]


urlencoded_char = "%" c0:[0-9a-fA-F] c1:[0-9a-fA-F] { 
    try {
        return decodeURI("%" + c0 + c1) 
    } catch ( e ) {
        // Reject the match, and allow other fall-back productions to have a
        // go at it.
        return null;
    }
}

//[^][<>"\\x00-\\x20\\x7F\p{Zs}]

no_punctuation_char = [^ :\]\[\n"'<>\x00-\x20\x7f,.&%\u00A0\u1680\u180E\u2000-\u200A\u202F\u205F\u3000]

url
  = proto:url_protocol 
    addr:( ipv6_address / ipv4_address )?
    rest:(  ( !inline_breaks 
              c:no_punctuation_char
              { return c }
            )
            / s:[.:,] !(space / eolf) { return s } 
            / htmlentity
            / urlencoded_char
            / [&%] )+ 
{ 
    return proto + addr + rest.join(''); 
}

ipv4_address 
  = a:([0-9]* '.' [0-9]* '.' [0-9]* '.' [0-9]*)
{
    return flatten( a ).join('');
}

ipv6_address 
  = a:('[' [0-9]* ':' [0-9]* ':' [0-9]* ':' [0-9]* ':' [0-9]* ':' [0-9]* ':' [0-9]* ']')
{
    return flatten( a ).join('');
}


/**************************************************************
 * Templates, -arguments and wikilinks
 **************************************************************/

/*
 * Precedence: template arguments win over templates. See 
 * http://www.mediawiki.org/wiki/Preprocessor_ABNF#Ideal_precedence
 * 4: {{{{·}}}} → {·{{{·}}}·}
 * 5: {{{{{·}}}}} → {{·{{{·}}}·}}
 * 6: {{{{{{·}}}}}} → {{{·{{{·}}}·}}}
 * 7: {{{{{{{·}}}}}}} → {·{{{·{{{·}}}·}}}·}
 */
tplarg_or_template = & '{{{{{' template / tplarg / template

template
  = "{{" target:template_param_text
    params:(newline? "|" newline? p:template_param { return p })* 
    "}}" {
      // Insert target as first positional attribute, so that it can be
      // generically expanded. The TemplateHandler then needs to shift it out
      // again.
      params.unshift( { k: '', v: flatten( target ) } );
      var obj = new SelfclosingTagTk( 'template', params );
      //console.warn( 'tokenizer template ' + JSON.stringify( target ));
      return obj;
  }

// XXX: support template and args in target!
//template_target
//  = h:( !"}}" x:([^|\n]) { return x } )* { return h.join('') }

tplarg 
  = "{{{" 
    name:template_param_text 
    params:( newline? "|" newline? p:template_param { return p })* 
    "}}}" {
      name = flatten( name );
      params.unshift( { k: '', v: name } );
      var obj = new SelfclosingTagTk( 'templatearg', params );
      //console.warn( 'tokenizer tplarg ' + JSON.stringify( obj, null, 2 ));
      return obj;
  }

template_param
  = name:template_param_name 
    s0:space* 
    eq:"="?
    s1:space*
    value:template_param_text?

    {
      //console.warn( 'named template_param matched' + pp([name, value ]) );
      if ( value !== '' ) {
        return new KV( name, flatten( value ) );
      } else if ( eq !== '' ) {
        return new KV(flatten( name ), []);
      } else {
        return new KV([], flatten(name));
      }
    } 
  // empty parameter
  / & [|}] { return new KV([], []); }


// FIXME: handle template args and templates in key! (or even parser functions?)
template_param_name
  = & { return setFlag( 'equal' ) }
    tpt:template_param_text
    {
        clearFlag( 'equal' );
        //console.warn( 'template param name matched: ' + pp( tpt ) );
        return tpt;
    }

  / & { return clearFlag( 'equal' ) }
  //= h:( !"}}" x:([^=|\n]) { return x } )* { return h.join(''); }

template_param_text
  = & { return setFlag('template') }
    il:inline {
        clearFlag('template');
        //console.warn( 'tpt match: ' + pp (il));
        return il;
    }
  / & { return clearFlag('template'); }

// TODO: handle link prefixes as in al[[Razi]]
wikilink
  = "[[" 
    ! url
    //target:link_target 
    target:wikilink_preprocessor_text
    lcontent:( "|" lt:link_text { return lt } )* 
    "]]" 
    // XXX In real MediaWiki, this is a language-dependent positive character
    // class. Can we work out a static negative class instead?
    // XXX: Exclude uppercase chars from non-latin languages too!
    trail:(! [A-Z \t(),.:-] tc:text_char { return tc })* {
      var obj = new SelfclosingTagTk( 'wikilink' ),
          textTokens = [];
      obj.attribs.push( new KV('href', target) );

      // Deal with content. XXX: Properly support pipe-trick etc
      if (lcontent && lcontent.length) {
          textTokens = lcontent;
          if (trail) {
            textTokens.push( trail.join('') );
          }
      } else {
          if (trail) {
              textTokens = $.extend(true, [], target).concat( [ trail.join('') ] );
          } else {
              // copy list
              textTokens = $.extend(true, [], target);
          }
      }

      obj.attribs.push( new KV( 'content', flatten( textTokens ) ) );
      //console.warn( "XXX:" + pp([obj].concat(textTokens, [new EndTagTk( 'a' )])) );
      return [obj];
  }

link_text
  = & { return setFlag('linkdesc'); }
    h:inline 
    // 'equal' syntaxFlag is set for links in template parameters. Consume the
    // '=' here.
    hs:( '=' inline)?
    { 
        //console.warn('link_text' + pp(h) + pp(hs));
        clearFlag('linkdesc');
        if( hs !== '' ) {
            return h.concat(hs);
        } else {
            return h;
        }
    }
  / & { return clearFlag('linkdesc'); }

link_end = "]]"

/* Generic quote production for italic and bold, further processed in a token
 * stream transformation in doQuotes. Relies on NlTk tokens being emitted
 * for each line of text to balance quotes per line.
 * 
 * We are not using a simple pair rule here as we need to support mis-nested
 * bolds/italics and MediaWiki's special heuristics for apostrophes, which are
 * all not context free. */
quote = "''" x:"'"* {
	var res = new TagTk( 'mw-quote' ); // Will be consumed in token transforms
    res.value = "''" + x.join('');
    return res;
}



/***********************************************************
 * Pre and xmlish tags
 ***********************************************************/

// Indented pre blocks differ from their non-indented (purely tag-based)
// cousins by having their contents parsed.
pre_indent 
  = pre_indent_in_tags
  / l:pre_indent_line ls:(sol pre_indent_line)* {
      return [new TagTk( 'pre' )]
                    .concat( [l], ls
                           , [new EndTagTk( 'pre' )]);
  }

// An indented pre block that is surrounded with pre tags. The pre tags are
// used directly.
pre_indent_in_tags
  = space+ // XXX: capture space for round-tripping
    "<pre" 
    attribs:generic_attribute* 
    ">"
    & { return setFlag('pre'); }
    l:inlineline
    ls:(sol pre_indent_line)*
    "</pre>"
  {   
    clearFlag('pre');
    return [ new TagTk( 'pre', attribs ) ]
        .concat( l, flatten( ls ), [ new EndTagTk( 'pre' ) ] );
  }
  / & { return clearFlag('pre'); }

pre_indent_line = space l:inlineline { 
    return [ '\n' ].concat(l); 
}

/*
 * Pre blocks defined using non-indented HTML tags only parse nowiki tags
 * inside them, and convert other content to verbatim text. Nowiki inside pre
 * is not functionally needed, but supported for backwards compatibility.
 */
pre
  = "<pre" 
    attribs:generic_attribute* 
    ">"
    // MediaWiki <pre> is special in that it converts all pre content to plain
    // text.
    ts:(t1:[^<]+ { return t1.join('') } 
                / nowiki 
                / !"</pre>" t2:. { return t2 })+ 
    ("</pre>" / eof) {
        // return nowiki tags as well?
        //console.warn('inpre');
        return [ new TagTk( 'pre', attribs ) ]
                    .concat(ts, [ new EndTagTk( 'pre' ) ]);
    }
  / "</pre>" { return "</pre>"; }

/* XXX: Extension tags can require a change in the tokenizer mode, which
 * returns any text between extension tags verbatim. For now, we simply
 * continue to parse the contained text and return the tokens. The original
 * input source can be recovered from the source positions added on tag
 * tokens. This won't however work in all cases. For example, a comment start
 * (<!--) between extension tags would cause the remaining text to be consumed
 * as a comment. To avoid this, we might need to look ahead for the end tag
 * and limit the content parsing to this section. */

xmlish_tag = nowiki / generic_tag

/*
 * Nowiki treats anything inside it as plain text. It could thus also be
 * defined as an extension that returns its raw input text, possibly wrapped
 * in a span for round-trip information. The special treatment for nowiki in
 * pre blocks would still remain in the grammar though, so overall handling it
 * all here is cleaner.
 */
nowiki 
  = "<nowiki>" nc:nowiki_content "</nowiki>" { 
        //console.warn( 'full nowiki return: ' + pp(nc)); 
        return nc; 
    }
  / "<nowiki>" { 
          //console.warn('nowiki fallback');
          return ['<nowiki>']; 
    }
  / "</nowiki>" { 
      //console.warn('nowiki end fallback');
      return ['</nowiki>']; 
  }

nowiki_content
  = ts:(   t:[^<]+ { return t.join('') } 
           / "<pre" p0:space* p1:[^>]* ">" p2:nowiki_content "</pre>" {
                 //console.warn('nested pre in nowiki');
                 return ["<pre"].concat(p0, p1, [">"], p2, ["</pre>"]).join('');
               }
           / (!("</"( "nowiki>" / "pre>")) c:. {
               //console.warn('nowiki: single char' + c);
               return c;
           }) 
       )* {
            // return nowiki tags as well?
            //console.warn('nowiki_content: return' + pp(ts));
            return [ts.join('')];
          }


// The list of HTML5 tags, mainly used for the identification of non-html
// tags. These terminate otherwise tag-eating productions (see list below) in
// order to support potential extension tags:
// * comment
// * pre
// * nowiki
html5_tagnames 
  = "a" / "abbr" / "address" / "area" / "article" 
    / "aside" / "audio" / "b" / "base" / "bdi" / "bdo" / "blockquote" 
    / "body" / "br" / "button" / "canvas" / "caption" / "cite" / "code" 
    / "col" / "colgroup" / "command" / "data" / "datalist" / "dd" / "del" 
    / "details" / "dfn" / "div" / "dl" / "dt" / "em" / "embed" / "fieldset" 
    / "figcaption" / "figure" / "footer" / "form" 
    / "h1" / "h2" / "h3" / "h4" / "h5" / "h6" / "head" / "header" / "hgroup" 
    / "hr" / "html" / "i" / "iframe" / "img" / "input" / "ins" / "kbd" / "keygen" 
    / "label" / "legend" / "li" / "link" / "map" / "mark" / "menu" / "meta" 
    / "meter" / "nav" / "noscript" / "object" / "ol" / "optgroup" / "option" 
    / "output" / "p" / "param" / "pre" / "progress" / "q" / "rp" / "rt" 
    / "ruby" / "s" / "samp" / "script" / "section" / "select" / "small" 
    / "source" / "span" / "strong" / "style" / "sub" / "summary" / "sup" 
    / "table" / "tbody" / "td" / "textarea" / "tfoot" / "th" / "thead" / "time" 
    / "title" / "tr" / "track" / "u" / "ul" / "var" / "video" / "wbr"

html_oldnames = "center" / "font" / "tt"

// Simple match on non-html endtags, for use in inline_breaks
nonhtml_endtag
  = '</' 
    ! ( html5_tagnames / html_oldnames )
    [^ >]+
    ( space / newline ) *
    [^>]*
    '>'

/* Generic XML-like tags
 * 
 * These also cover extensions (including Cite), which will hook into the
 * token stream for further processing. The content of extension tags is
 * parsed as regular inline, but the source positions of the tag are added 
 * to allow reconstructing the unparsed text from the input. */

// See http://dev.w3.org/html5/spec/Overview.html#syntax-tag-name and
// following paragraphs
generic_tag
  = "<" 
    & { tagStartPos = pos; return true; } // remember the start position of this tag
    end:"/"? name:[0-9a-zA-Z]+ 
    attribs:generic_newline_attribute* 
    ( space / newline ) *
    selfclose:"/"?
    ">" {
        name = name.join('');
        var res;
        if ( end != '' ) {
            res = new EndTagTk( name, attribs );
        } else if ( selfclose != '' ) {
            res = new SelfclosingTagTk( name, attribs );
        } else {
            res = new TagTk( name, attribs );
        }
        if ( res.dataAttribs === undefined ) {
            res.dataAttribs = {};
        }
        res.dataAttribs.sourceTagPos = [tagStartPos - 1, pos];
        return res;
    }

// A generic attribute that can span multiple lines.
generic_newline_attribute
  = s:( space / newline )* 
    name:generic_attribute_name
    value:(( space / newline )*
          v:generic_attribute_newline_value { return v })?
{
    if ( value !== '' ) {
        return new KV( name, value );
    } else {
        return new KV( name, '' );
    }
}

// A single-line attribute.
generic_attribute
  = s:space* 
    name:generic_attribute_name
    value:(space*
          v:generic_attribute_value { return v })?
{
    //console.warn( 'generic attribute: ' + pp([name, value]));
    // FIXME: name might just be a template, which can expand to a key-value
    // pair later. We'll need to handle that in the AttributeTransformManager.
    if ( value !== '' ) {
        return new KV( name, value );
    } else {
        return new KV( name, '' );
    }
}

// ( Replaced by generic_attribute_name for template / parameter support. )
//// http://dev.w3.org/html5/spec/Overview.html#attributes-0, and we also
//// disallow newlines, | and {.
//generic_attribute_plain_name
//  = n:[^ \t\0/"'>=\n|{]+ {
//        return n.join('');
//  }

generic_attribute_name
  = & { return setFlag( 'equal' ) }
  ! '/>'
  name:attribute_preprocessor_text_line
    {
        clearFlag( 'equal' );
        //console.warn( 'generic attribute name: ' + pp( name ) );
        return name;
    }
  / & { return clearFlag( 'equal' ) }

// A generic attribute, possibly spanning multiple lines.
generic_attribute_newline_value
  = "=" (space / newline )* v:xml_att_value { 
      return v; 
  }
// A generic but single-line attribute.
generic_attribute_value
  = "=" space* v:att_value { 
      return v; 
  }

// Attribute value, quoted variants can span multiple lines.
xml_att_value
  = "'" t:attribute_preprocessor_text_single "'" { return t; }
  / '"' t:attribute_preprocessor_text_double '"' { return t; }
  / attribute_preprocessor_text

// Attribute value, restricted to a single line.
att_value
  = "'" t:attribute_preprocessor_text_single_line "'" { return t; }
  / '"' t:attribute_preprocessor_text_double_line '"' { return t; }
  / attribute_preprocessor_text_line

/*
 * A variant of generic_tag, but also checks if the tag name is a block-level
 * tag as defined in
 * http://dev.w3.org/html5/spec/Overview.html#syntax-tag-name and following
 * paragraphs.
 */
block_tag
  = "<" end:"/"? 
    name:(cs:[a-zA-Z]+ { return cs.join('') })
    attribs:generic_newline_attribute* 
    ( space / newline ) *
    selfclose:"/"?
    ">" {
        if (block_names[name.toLowerCase()] !== true) {
            // abort match if tag is not block-level
            return null;
        }
        var res;
        if ( end != '' ) {
            res = new EndTagTk( name, attribs );
        } else if ( selfclose != '' ) {
            res = new SelfclosingTagTk( name, attribs );
        } else {
            res = new TagTk( name, attribs );
        }
        return [res];
    }


/*********************************************************
 *   Lists 
 *********************************************************/
lists = e:(dtdd / li) es:(sol (dtdd / li))*
{
    return annotateList( [ new TagTk( 'list' ) ]
            .concat(flatten([e].concat(es))
                ,[ new EndTagTk( 'list' ) ]));
}

li = bullets:list_char+ 
     c:inlineline?
     &eolf 
{
    if ( c === '' )
        c = [];
    var li = new TagTk( 'listItem' );
    li.bullets = bullets;
    return [ li, c ];
}

dtdd 
  = bullets:(!(";" !list_char) list_char)*
    ";"
    & {return setFlag('colon');}
    c:inlineline
    ":"
    // Fortunately dtdds cannot be nested, so we can simply set the flag
    // back to 0 to disable it.
    & {syntaxFlags['colon'] = 0; return true;}
    d:inlineline
    &eolf {
        // Convert trailing space into &nbsp;
        // XXX: This should be moved to a serializer
        //var clen = c.length;
        //if (clen && c[clen - 1].constructor === String) {
        //    var val = c[clen - 1].value;
        //    if(val.length && val[val.length - 1] == ' ') {
        //        c[clen - 1].value = val.substr(0, val.length - 1) + "\u00a0";
        //    }
        //}

        var li = new TagTk( 'listItem' );
        li.bullets = bullets + ";";
        var li2 = new TagTk( 'listItem' );
        li2.bullets = bullets + ":";
        return [ li ].concat( c, [ li2 ], d );
    }
  // Fall-back case to clear the colon flag
  / & { return true; } { syntaxFlags['colon'] = 0; return null; }


list_char = [*#:;]



/*********************************************************************
 * Tables 
 *
 * Table productions are geared to support independent parsing of fragments in
 * templates (the common table start / row / table end use case). The tokens
 * produced by these fragments then match up to a table while building the
 * DOM tree. For similar reasons, table rows do not emit explicit end tag
 * tokens.
 *
 * The separate table_lines production is faster than moving those productions
 * directly to block_lines.
 *********************************************************************/

table_lines
  = & { return setFlag('table'); }
    tl:table_line 
    tls:( s:sol tl2:table_line { return s.concat(tl2); } )* {
        clearFlag('table');
        //console.warn('table_lines: ' + pp(tl.concat(tls)));
        return tl.concat( tls );
    }
  / & { return clearFlag('table'); }

// This production assumes start-of-line position!
table_line
  = table_start_tag
  / table_row_tag
  / table_data_tags
  / table_heading_tags
  / table_caption_tag
  / table_end_tag

table_start_tag
  = "{|"
    ta:generic_attribute* 
    space*
    te:table_end_tag? // can occur somewhere in the middle of the line too
    { 
        var toks = [ new TagTk( 'table' ) ];
        if ( ta )
            toks[0].attribs = ta;
        if ( te )
            toks = toks.concat( te );
        return toks;
    }

table_caption_tag
  = "|+" 
    c:inline* { 
        return [ new TagTk( 'caption' )]
                    .concat( c, [ new EndTagTk( 'caption' ) ]);
    }


table_row_tag
  = //& { console.warn("table row enter"); return true; }
    "|-"
    a:generic_attribute*
    space*
    // handle tables with missing table cells after a row
    td:( s:sol ![|!] tdt:table_data_tag { return s.concat(tdt); } )?
    { 
        // We rely on our tree builder to close the row as needed. This is
        // needed to support building tables from fragment templates with
        // individual cells or rows.
        var trToken = [ new TagTk( 'tr', a ) ];
        if ( !td ) {
            return trToken;
        } else {
            return trToken.concat(td);
        }
    }

table_data_tags
  = pipe
    td:table_data_tag
    tds:( "||" tdt:table_data_tag { return tdt } )* {
        return td.concat(tds);
    }

table_data_tag
  = //& { dp("table_data enter, pos=" + pos + input.substr(pos,10)); return true; }
    ! [}+-]
    a:table_cell_args?
    //& { console.warn("past attrib, pos=" + pos + input.substr(pos,10)); return true; }
    // use inline_breaks to break on tr etc
    td:( //& { dp("table_data 2, pos=" + pos + input.substr(pos,10)); return true; }
         b:nested_block { return b } 
       )* 
    { 
        if ( a == '' ) {
            a = [];
        }
        //console.warn("table data result: " + pp(td) + ", attribts: " + pp(a));
        return [ new TagTk( 'td', a )]
                    .concat( td, [ new EndTagTk ( 'td' ) ] );
    }

table_heading_tags
  = "!"
    th:table_heading_tag
    ths:( "!!" tht:table_heading_tag  { return tht } )* {
        return th.concat(ths);
    }

table_heading_tag
  = a:table_cell_args?
    c:inline {
         if ( a == '' ) {
             a = [];
         }
         return [ new TagTk( 'th', a ) ]
						.concat( c, [new EndTagTk( 'th' )] );
     }

table_end_tag
  = "|}" { 
      var tok = [new EndTagTk( 'table' )];
	  return tok;
  }

table_cell_args
  = & { return setFlag('tableCellArg'); }
    as:generic_attribute+ space* "|" !"|" { 
        clearFlag('tableCellArg');
        return as;
    }
    / & { return clearFlag('tableCellArg'); }



/* Tables, full-table version (no support for table fragments from templates) 
 * Only left here for comparison purposes with the above productions. Remove
 * when those work as intended! */
table 
  = tas:table_start space* c:table_caption? b:table_body? te:table_end { 
      var res = new TagTk( 'table' );
      var body = b !== '' ? b : [];
      //dp("body: " + pp(body));
      if (tas.length > 0) {
          // FIXME: actually parse and build structure
          //res.attribs = [new KV('data-unparsed', tas.join(''))];
          res.attribs = tas;
      }

      if (c != '') {
          var caption = [ new TagTk( 'caption' ) ]
                        .concat(c, [new EndTagTk( 'caption' )], te);
      } else {
          var caption = [];
      }
      //dp(pp(res));

      return [res].concat(caption, body, [new EndTagTk( 'table' )]);
  }

table_start 
  = "{" pipe
    res:(
        & { setFlag('table'); return true; }
        ta:generic_attribute* 
        { 
            //dp("table_start " + pp(ta) + ", pos:" + pos);
            return ta;
        }
        / & { clearFlag('table'); return false; } { return null; }
    ) { return res }

table_caption 
  = n:newlineToken
    pipe "+" c:inline* { 
        return n.concat(c);
    }

table_body 
  = //& { dp("table_body enter"); return true; }
    firstrow:table_firstrow otherrows:table_row* { 
      /* dp('table first and otherrows: ' 
       * + pp([firstrow].concat(otherrows))); */
      return [firstrow].concat(otherrows); 
  }
  / otherrows:table_row* {
      //dp('table otherrows: ' + pp(otherrows));
      return otherrows;
  }

table_firstrow 
  = td:(table_data / table_heading)+ { 
      //dp('firstrow: ' + pp(td));
      return [ new TagTk( 'tr' )]
             .concat(td, [ new EndTagTk( 'tr' )]);
  }

table_row 
  = //& { dp("table row enter"); return true; }
  n:newlineToken
    pipe "-" 
    a:(as:generic_attribute+ space* pipe !pipe { return as } )?
    space* 
    td:(table_data / table_heading)* { 
        return n.concat([ new TagTk( 'tr' )]
					   , td, [ new EndTagTk( 'tr' )]);
    }

table_data 
  = //& { dp("table_data enter, pos=" + pos + input.substr(pos,10)); return true; }
	n:("||" { return [] } / nt:newlineToken (pipe / !'!') { return nt }) 
    ! [}+-]
    //& { dp('before attrib, pos=' + pos); return true; }
    a:(as:generic_attribute+ space* pipe !pipe { return as } )?
    //& { dp('past attrib, pos=' + pos); return true; }
    // use inline_breaks to break on tr etc
    td:(
        //& { dp("table_data 2, pos=" + pos + input.substr(pos,10)); return true; }
        b:nested_block { return b }
       )* { 
        if ( a == '' ) {
            a = [];
        }
        //dp("table data result: " + pp(td) + ", attribts: " + pp(a));
        return n.concat( [ new TagTk( 'td',  a ) ]
					   , td, [ new EndTagTk( 'td' ) ] );
    }

table_heading
  = n:("!!" { return [] } / nl:newlineToken "!" { return nl }) 
    a:(as:generic_attribute+ pipe !pipe { return as } )?
     c:inline {
         if ( a == '' ) {
             a = [];
         }
         return n.concat( [ new TagTk( 'th', a )]
						, c, [ new EndTagTk( 'th' ) ]);
     }

thtd_attribs
  // In particular, do not match [|\n]
  = a:(text / ! inline_breaks c:[="':;/,. -] { return c } )+ pipe ! pipe {
    return a;
  }


table_end 
  = nt:newlineToken? ( pipe "}" / eof ) { 
	  clearFlag('table'); 
	  if(nt) 
		  return nt;
	  else
		  return [];
  }



/*******************************************************************
 * Text variants and other general productions
 *******************************************************************/

/* All chars that cannot start syntactic structures in the middle of a line
 * XXX: ] and other end delimiters should probably only be activated inside
 * structures to avoid unnecessarily leaving the text production on plain
 * content. */

text_char = [^'<~[{\n\r:\]}|!=]

text = t:text_char+ { return t.join(''); }

/* Legend
 * '    quotes (italic/bold)
 * <    start of xmlish_tag
 * ~    signatures/dates
 * [    start of links
 * {    start of parser functions, transclusion and template args
 * \n   all sort of block-level markup at start of line
 * \r   ditto
 * h    http(s) urls
 * n    nntp(s) urls
 * m    mailto urls
 *
 * ! and | table cell delimiters, might be better to specialize those
 * =    headings - also specialize those!
 *
 * The following chars are also included for now, but only apply in some
 * contexts and should probably be enabled only in those:
 * :    separate definition in ; term : definition
 * ]    end of link
 * }    end of parser func/transclusion/template arg
 */

urltext = ( t:[^'<~[{\n\rfghimnstw|!:\]} &=]+ { return t.join(''); }
          / & url_chars urllink
          / htmlentity 
          // Convert trailing space into &nbsp;
          // XXX: This should be moved to a serializer
          / ' ' & ':' { return "\u00a0"; }
          / t:text_char )+

/*
	'//', // for protocol-relative URLs, but not in text!
	'ftp://',
	'git://',
	'gopher://',
	'http://',
	'https://',
	'irc://',
	'ircs://',  // @bug 28503
	'mailto:',
	'mms://',
	'news:',
	'nntp://', // @bug 3808 RFC 1738
	'svn://',
	'telnet://', // Well if we're going to support the above.. -ævar
	'worldwind://',
*/

// Old version
//text = t:[A-Za-z0-9,._ "?!\t-]+ { return t.join('') }

// Experimental tweaked version: avoid expensive single-char substrings
// This did not bring the expected performance boost, however.
//text = [A-Za-z0-9,._ -] { 
//            textStart = pos;
//
//            var res = input.substr(textStart - 1, inputLength)
//                        .match(/[A-Za-z0-9,._ -]+/)[0];
//            pos = pos + (res.length - 1);
//            return res
//       }

htmlentity = "&" c:[#0-9a-zA-Z]+ ";" { 
    return unentity("&" + c.join('') + ";") 
}

space
  = s:[ \t]+ { return s.join(''); }

optionalSpaceToken
  = s:space* {
      if ( s.length ) {
          return [s.join('')];
      } else {
          return [];
      }
  }


// Start of line
sol = nl:(newlineToken / & { return pos === 0; } { return [] }) 
      // Eat multi-line comments, so that syntax after still matches as if it
      // was actually preceded by a newline
      cn:( c:comment n:newline? { 
                if ( n !== '' ) {
                    return [c, n];
                } else {
                    return [c];
                }
            }
      )*
      // Eat includeonly/noinclude at start of line, so that start-of-line
      // syntax after it still matches
      ni:(space* "<" c:"/"? t:("includeonly" / "noinclude") ">" {return [c, t]} )?
      {
          var niToken = [];
          if ( ni !== '') {
              if ( ni[0] === '/' ) {
                  niToken = [new EndTagTk( ni[1] )];
              } else {
                  niToken = [new TagTk( ni[1] )];
              }
          }
                  
          return nl.concat(cn, niToken);
      }

eof = & { return isEOF(pos); } { return true; }


newline
  = '\n' / '\r\n'

newlineToken = newline { return [new NlTk()] }

eolf = newline / eof


// 'Preprocessor' directive- higher-level things that can occur in otherwise
// plain-text content.
directive
  = comment
  / nowiki
  / tplarg_or_template
  / htmlentity 

// Plain text, but can contain templates, template arguments, comments etc-
// all stuff that is normally handled by the preprocessor
// Returns either a list of tokens, or a plain string (if nothing is to be
// processed).
preprocessor_text 
  = r:( t:[^<~[{\n\r\t|!\]} &=]+ { return t.join(''); }
  / directive
  / !inline_breaks text_char )+ {
      return flatten ( r );
  }

spaceless_preprocessor_text
  = r:( t:[^'<~[{\n\r|!\]}\t &=]+ { return t.join(''); }
  / directive
  / !inline_breaks !' ' text_char )+ {
      return flatten_string ( r );
  }


wikilink_preprocessor_text 
  = r:( t:[^%<~[{\n\r\t|!\]} &=]+ { return t.join(''); }
  / urlencoded_char
  / directive
  / !inline_breaks !"]]" text_char )+ {
      return flatten_stringlist ( r );
  }

extlink_preprocessor_text
  = r:( t:[^'<~[{\n\r|!\]}\t&="' \u00A0\u1680\u180E\u2000-\u200A\u202F\u205F\u3000]+ { return t.join(''); }
  / directive
  / urlencoded_char
  / !inline_breaks no_punctuation_char
  / s:[.:,] !(space / eolf) { return s } 
  / [&%] )+ {
      return flatten_string ( r );
  }

// Attribute values with preprocessor support
attribute_preprocessor_text
  = r:( ts:(!inline_breaks t:[^=<>{\n\r&'"\t ] {return t})+ { return ts.join(''); }
  / directive
  / !inline_breaks [&%] )+ {
      //console.warn('prep');
      return flatten_string ( r );
  }
attribute_preprocessor_text_single
  = r:( t:[^{&']+ { return t.join(''); }
  / directive
  / !inline_breaks [{&] )* {
      return flatten_string ( r );
  }
attribute_preprocessor_text_double
  = r:( t:[^{&"]+ { return t.join(''); }
  / directive
  / !inline_breaks [{&] )* {
      //console.warn( 'double:' + pp(r) );
      return flatten_string ( r );
  }

// Variants with the entire attribute on a single line
attribute_preprocessor_text_line
  = r:( ts:(!inline_breaks t:[^=<>{\n\r&'"\t ] {return t})+ { return ts.join(''); }
  / directive
  / !inline_breaks !'\n' [&%] )+ {
      //console.warn('prep');
      return flatten_string ( r );
  }
attribute_preprocessor_text_single_line
  = r:( t:[^{&']+ { return t.join(''); }
  / directive
  / !inline_breaks !'\n' [{&] )* {
      return flatten_string ( r );
  }
attribute_preprocessor_text_double_line
  = r:( t:[^{&"]+ { return t.join(''); }
  / directive
  / !inline_breaks !'\n' [{&] )* {
      //console.warn( 'double:' + pp(r) );
      return flatten_string ( r );
  }

// Special-case support for those pipe templates
pipe = "|" / "{{!}}"

/* Tabs do not mix well with the hybrid production syntax */
/* vim: set filetype=javascript expandtab ts=4 sw=4 cindent : */