// create toggle for wiki feature
document.writeln('<form name="wiki"><input type="checkbox" name="on">wiki?</form><br>');

var textarea=get_textarea();

// obsolet
var allowed_nodes = {479:'perlquestion',480:'perlmeditation',1040:'monkdiscuss', 1597: 'obfuscated',1044:'CUFP'};



if ( textarea ) {
    // activate wikifeature
    document.forms.wiki.elements.on.checked=true;
    // window.alert('wiki enabled!!!');
} 


var text;

/*
  expand wiki code to monk code with capital letters
*/
  
function wiki2monks () {
    if ( textarea && document.forms.wiki.elements.on.checked) {
        text=textarea.value;

        // constants regex
        var singleword = '\\S+' ;
        var singleline = '\\S|\\S.*?\\S' ;
        
        //******* protect special areas
        text = init_exclusions(text);  
        text = exclude_all(text); 

        //******* Replace Inline Markup
        
        //*** autolinks to modules, pragmas, cpan
        text=text.replace(/(\s)(\w+::\w[\w:]*)(\s)/g,link_module);

        //*** normalize newlines
        text=text.replace(/\r\n/g,'\n'); // IE sucks!
        
        //*** 'inline code' -> '...'
        around_words('inline code', 'C', "'", singleline);
        text = exclude_all(text); // protect new code areas

        //*** ?documentation? -> [DOC://...]
        text=text.replace(/(\s)\?(\S+)\?(\s)/g,'$1[DOC://$2|<tt>$2</tt>]$3');
        text = exclude_all(text); // protect new doc areas

        
        //*** emphasizer * / _ -> <B><I><U>
        around_words('bold',      'B', '*', singleword);
        around_words('italic',    'I', '/', singleword);
        around_words('underline', 'U', '_', singleword);


        
        //****** complete lines (markup at start of line)

        //*** > quotes   ->   <I> > ... </I> 
        text=text.replace(/(^|\n\n)(> )([^]*?)(?=\n\n|$)/g,'$1<I>&gt; $3</I>');   // quote 

        //*** \n=== headlines -> <H6>...</H6>
        text = heading(text);

        //*** - list items -> <LI>...</LI>
        // paragraphs starting with (-)+ = (un)orderd
        text=text.replace(/(\n)(\n-\s+[^]*?)(\n\n)/g,'$1<UL\>$2\n<\/UL\>\n');   // bullets unordered
        text=text.replace(/(\n)(\n\+\s+[^]*?)(\n\n)/g,'$1<OL\>$2\n<\/OL\>\n');   // bullets ordered

        text=text.replace(/^(\-|\+)(\s+.*?)$/gm,'<LI\>$2'); // bullets (simple)
        
        //*** paragraph
        text=text.replace(/(\n\n+)/g,'<P\>$1');                   // paragraph

        //****** reinclude protected areas
        text = include_all(text);
        
        textarea.value=text;
    }
}


/*
  replace words surrounded by wikitags with pm markup
  eg " *words* " -> " <B>words</B> "
*/

function around_words ( doc, monk_tag, wiki_tag, inner_re) {
    var empty      = '(^|\\s|$)';
    var marker     = '(\\' + wiki_tag + ')';
    var inner_grp  = '('   + inner_re + ')';
    var regex      = new RegExp( empty + marker + inner_grp + marker + empty, 'g');
    var pre_tag    = '<'  + monk_tag + '>';
    var post_tag   = '</' + monk_tag + '>';
    var substitute = '$1' + pre_tag + '$3' + post_tag + '$5';
    // console.log(doc,regex,substitute); 
    text=text.replace( regex, substitute);        
}

function around_paragraph ( doc, monk_tag, wiki_tag, inner_re) {
    //stub
}

/*
  transform headlines (both ways)
  eg "^=== text" <-> <H5>text</H5>
*/

function heading (text,revert) {
    var maps =[
        ['===', 'H5'],
        ['==' , 'H4'],
        ['='  , 'H3'],
    ];
    if (revert) {
        for (var i=maps.length-1; i>=0 ;i--) {
            var map=maps[i];
            var tag0 = new RegExp( '<'+ map[1] + '>','g');
            text=text.replace(tag0,map[0]);
            var tag1 = new RegExp( '</'+ map[1] + '>','g');
            text=text.replace(tag1,'');
        }
    } else {
        
        for (var i=0; i<maps.length;i++) {
            var map=maps[i];
            var from = new RegExp( '^(' +map[0]+ ')(\\s.*?)$','gm');
            var to   = '<'+ map[1] + '>$2</' + map[1] +'>';
            // console.log(from + ' -> ' + to);
            text=text.replace(from,to);
        }
    }
    return text;    
}


/* revert PM markup back to wiki markup */

function monks2wiki () {

    if ( textarea && document.forms.wiki.elements.on.checked) {
        var text=textarea.value;

        // protect areas like code sections
        text = exclude_all(text); 

        // delete <P>
        text=text.replace(/<P>/g,''); 

        // no quote
        text=text.replace(/(^|\n\n)<I>(&gt; )([^]*?)<\/I>(?=\n\n|$)/g,'$1> $3');
        
        // revert around word markup
        text=text.replace(/<\/?I>/g,'/'); 
        text=text.replace(/<\/?B>/g,'*');
        text=text.replace(/<\/?U>/g,'_');

        
        // revert listitems
        text=text.replace(/<LI>/g,'-');
        text=text.replace(/<\/?(U|O)L>/g,'');

        // revert <H3>..<H5>
        text = heading(text,1); 

        // reinclude protected areas
        text = include_all(text);

        // revert ' (was protected)  
        text=text.replace(/<\/?C>/g,"'");
        
        textarea.value=text;
    }
}



function link_module(match, pre, name, post, offset, string) {
    var core_modules = {
        'B::Deparse' : 1,
    };
    var protokoll= core_modules[name] ? 'doc' : 'metamod';
    return pre+'['+protokoll.toUpperCase()+'://'+name+']'+post;
}

(function (){

    var DBG=false;
    var counter=0;
    // var matches    = [];
    var exclusions = [];
    var delim="\0"; 
    var delim0=delim+"<<";
    var delim1=">>"+delim;

    init_exclusions =function (text) {
        exclusions = [];
        counter=0;
        text = exclude(text,new RegExp(delim+"+","g"),"delim");
        return text;
    }

    exclude_all = function (text){
        text = exclude(text,/<(c|code)>[^]*?<\/\1>/g,"code");
        text = exclude(text,/\[(\w+):\/\/.*?\]/g,"link");
        text = exclude(text,/<nowiki>[^]*?<\/nowiki>/g,"nowiki");
        text = exclude(text,/<\w+\s+.+?>/g,"innertag");
        text = exclude(text,new RegExp("<"+"!--[^]*?--"+">","g"),"comment");
        if (DBG) console.log(exclusions);

        return text;
    }
    
    function exclude(text,pattern,name){

        var text_out=text;
        var match;
        while (match = pattern.exec(text)) {
            // if (DBG) console.log(match);
            
            var substring = match[0];
            
            var placeholder = name.toUpperCase();
            if (match[1]) placeholder += "_"+match[1];
            placeholder = delim0 + placeholder + "_" +counter + delim1;

            text_out = text_out.replace( substring, placeholder );
            // matches[counter] = substring;
            exclusions.push( [placeholder,substring] );
            counter++;
        }
        return text_out;   
    }



    include_all = function (text){
        var exclusion;
        while ( exclusion = exclusions.pop() ){
            var placeholder = exclusion[0];
            var substring     = exclusion[1];
            substring = substring.replace(/\$/g,'$$$$'); // escape $ to avoid interpolation
            text = text.replace( placeholder, substring );
        }
        return text;   
    }

})();

/* textareas meant for posting discussions have names ending on '_doctext' */ 
function get_textarea() {
    var T=document.getElementsByTagName("textarea");
    for (var i in T) {
        var n=T[i].name ;
        if (n && n.match(/_doctext$/))
            return T[i];
    }
} 

if (textarea) {
   // after pageload revert upercase PM markup to original wikicode
   window.onload= monks2wiki;

   // on submit of form wikisyntax to PM markup
   textarea.form.onsubmit = wiki2monks;
}


// ********** test code **********
/* test heading() */
function t_heading () {
    var t='= eins\n== zwei\n=== drei';
    //console.log(t);
    var a=heading(t);
    //console.log(a);
    var b=heading(a,1);
    //  console.log(b);
    var a=heading(b);
    var b=heading(a,1);
    if (t!=b) {
        console.log('heading test FAILED: \n'+t+'\n->\n'+a+'\n->\n'+b);
    } else {
        console.log("heading test OK");
    }
}

/* END OF WIKIFEATURE */