GDN Syntax Parser

<?php

global $smilies;
$smilies = array( ":)" => "glad.png",
                  ":(" => "sad.png",
                  ":p" => "tongue.png",
                  ":P" => "tongue.png",
                  ":o" => "surprised.png",
                  ":O" => "surprised.png",
                  ":d" => "happy.png",
                  ":D" => "happy.png",
                  ":s" => "confused.png",
                  ":S" => "confused.png",
                  "B)" => "cool.png",
                  "-_-'" => "dissapointed.png",
                  ";)" => "wink.png",
                  ">_<" => "upset.png",
                  "&gt;_&lt;" => "upset.png",
                  "^^" => "satisfied.png" );

global $elements_noparse;
$elements_noparse = array( "noparse" => "___CONTENT___",
                           "code" => "<pre>___CONTENT___</pre>",
                           "inl" => "<tt>___CONTENT___</tt>" );

global $elements_nocontent;
$elements_nocontent = array( "img" => '<img class="forum-image" src="___ARGUMENT___" alt="___ARGUMENT___" border="0" />' );

global $elements_noargs;
$elements_noargs = array( "b" => '<strong>___CONTENT___</strong>',
                          "u" => '<span style="text-decoration: underline">___CONTENT___</span>',
                          "i" => '<em>___CONTENT___</em>',
                          "s" => '<span style="text-decoration: line-through">___CONTENT___</span>',
                          "center" => '<div style="text-align: center">___CONTENT___</div>',

                          "url" => '<a href="___CONTENT___">___CONTENT___</a>',
                          "img" => '<img class="forum-image" src="___CONTENT___" border="0" />',
                          "quote" => '<blockquote>___CONTENT___</blockquote>',

                          "*" => '<li>___CONTENT___</li>',
                          "list" => '<ol>___CONTENT___</ol>',
                          "ulist" => '<ul>___CONTENT___</ul>',

                          "h1" => '<h2>___CONTENT___</h2>',
                          "h2" => '<h3>___CONTENT___</h3>',
                          "h3" => '<h4>___CONTENT___</h4>',
                          "h4" => '<h5>___CONTENT___</h5>',
                          "h5" => '<h6>___CONTENT___</h6>',

                          "user" => '<a href="user.php?un=___CONTENT___">___CONTENT___</a>' );

global $elements_args;
$elements_args = array( "url" => '<a href="___ARGUMENT___">___CONTENT___</a>',

                        "quote" => '<blockquote><span class="quote-user">Posted by ___ARGUMENT___: </span><br/>___CONTENT___</blockquote>',

                        "font" => '<span style="font-family: ___ARGUMENT___">___CONTENT___</span>',
                        "size" => '<span style="font-size: ___ARGUMENT___">___CONTENT___</span>',
                        "color" => '<span style="color: ___ARGUMENT___">___CONTENT___</span>' );

function FindAllOccurences( $haystack, $needle )
{
    $toReturn = array();

    $foundPos = 0;
    while ( true )
    {
        $found = stripos( $haystack, $needle, $foundPos + 1 );

        if ( $found === false )
        {
            break;
        }

        $toReturn[] = $foundPos = $found;
    }

    return $toReturn;
}

function DoNoparseStuff( $text )
{
    global $elements_noparse;
    global $npLastFound;
    global $npLastFoundCode;

    $tmpFound = false;
    $tmpCode = false;
    foreach ( $elements_noparse as $code => $format )
    {
        $foundIt = strpos( $text, '[' . $code . ']', $npLastFound );
        if ( $foundIt !== false and ( $tmpFound === false or $tmpFound > $foundIt ) )
        {
            $tmpCode = $code;
            $tmpFound = $foundIt;
        }
    }

    $npLastFound = $tmpFound;
    $npLastFoundCode = $tmpCode;
}

function nl2br_custom( $text )
{
    $text = str_replace( "\r\n", "\n", $text );
    $text = str_replace( "\r", "\n", $text );

    $tokens = explode( "\n", $text );

    $str = '';
    $nsf = 1;
    $c = count( $tokens );
    foreach ( $tokens as $key => $value )
    {
        $str .= $value;

        $trimmed = trim( $value );
        $last3Chars = substr( $trimmed, strlen( $trimmed ) - 3, 3 );
        $last4Chars = substr( $trimmed, strlen( $trimmed ) - 4, 4 );
        $last5Chars = substr( $trimmed, strlen( $trimmed ) - 5, 5 );
        $last6Chars = substr( $trimmed, strlen( $trimmed ) - 6, 6 );
        if ( $nsf != $c and $last3Chars != "/*]" and $last4Chars != "/h1]" and $last4Chars != "/h2]" and $last4Chars != "/h3]" and $last4Chars != "/h4]" and $last4Chars != "/h5]" and $last5Chars != "list]" and $last6Chars != "ulist]" )
        {
            $str .= "<br/>\n";
        }
        else
        {
            $str .= "\n";
        }
        ++$nsf;
    }

    return $str;
}

function Parse( $text )
{
    global $elements_args;
    global $elements_noargs;
    global $elements_nocontent;
    global $elements_noparse;
    global $smilies;

    $foundSome = false;
    foreach ( $elements_noparse as $code => $format )
    {
        if ( strpos( $text, '[' . $code . ']' ) !== false and strpos( $text, '[/' . $code . ']' ) !== false )
        {
            $foundSome = true;
        }
    }

    $sections = array();
    if ( !$foundSome )
    {
        $sections[] = array( $text => true );
    }
    else
    {
        global $npLastFound;
        global $npLastFoundCode;
        $npLastFound = 0;
        $lastSection = 0;
        for ( DoNoparseStuff( $text ); $npLastFound !== false; DoNoparseStuff( $text ) )
        {
            $tag = $npLastFoundCode;
            $tagStart = '[' . $tag . ']';
            $tagEnd = '[/' . $tag . ']';

            $endFound = strpos( $text, $tagEnd, $npLastFound );
            if ( $endFound === false  )
            {
                $npLastFound += strlen( $tagStart );
                continue;
            }

            $sections[] = array( substr( $text, $lastSection, $npLastFound - $lastSection ) => true );
            $sections[] = array( substr( $text, $npLastFound, $endFound + strlen( $tagEnd ) - $npLastFound ) => $tag );

            $lastSection = $endFound + strlen( $tagEnd );
            $npLastFound += strlen( $tagStart );
        }
        $sections[] = array( substr( $text, $lastSection, strlen( $text ) - $lastSection ) => true );
    }

    $parsedText = "";
    foreach ( $sections as $key => $sectionInfo )
    {
        $theKeyList = array_keys( $sectionInfo );
        $toParseOriginal = $theKeyList[ 0 ];
        $toParse = htmlentities( $toParseOriginal );
        if ( $sectionInfo[ $toParseOriginal ] !== true )
        {
            $format = $elements_noparse[ $sectionInfo[ $toParseOriginal ] ];
            $tag = $sectionInfo[ $toParseOriginal ];
            if ( $tag !== 'code' and $tag != 'inl' )
            {
                $toParse = nl2br_custom( $toParse );
            }
            $stuff = $toParse;
            $stuff = str_replace( '[' . $tag . ']', '', $stuff );
            $stuff = str_replace( '[/' . $tag . ']', '', $stuff );
            $parsed = str_replace( '___CONTENT___', $stuff, $format );
            $parsedText .= $parsed;
            continue;
        }
        $toParse = trim( $toParse );
        $toParse = nl2br_custom( $toParse );

        foreach ( $smilies as $smily => $image )
        {
            for ( $lastFound = strpos( $toParse, $smily ); $lastFound !== false; $lastFound = @strpos( $toParse, $smily, $lastFound + 1 ) )
            {
                $contents = '<img class="smily" src="res/' . $image . '" alt="' . htmlentities( $smily ) . '" />';

                $replaceEnd = $lastFound + strlen( $smily );
                $stuff = substr( $toParse, $lastFound, $replaceEnd - $lastFound );
                $toParse = str_replace( $stuff, $contents, $toParse );
                $lastFound = $lastFound + strlen( $contents );
            }
        }

        foreach ( $elements_noargs as $code => $format )
        {
            $codeStart = '[' . $code . ']';
            $codeEnd = '[/' . $code . ']';
            for ( $lastFound = strpos( $toParse, $codeStart ); $lastFound !== false; $lastFound = @strpos( $toParse, $codeStart, $lastFound + 1 ) )
            {
                $endFound = strpos( $toParse, $codeEnd, $lastFound );
                if ( $endFound === false )
                {
                    continue;
                }

                $contentsStart = $lastFound + strlen( $codeStart );
                $contents = substr( $toParse, $contentsStart, $endFound - $contentsStart );

                $guts = str_replace( "___CONTENT___", $contents, $format ); // Couldn't think of a name, ok? :P
                $replaceEnd = $endFound + strlen( $codeEnd );
                $stuff = substr( $toParse, $lastFound, $replaceEnd - $lastFound );
                $toParse = str_replace( $stuff, $guts, $toParse );
                $lastFound = $lastFound + strlen( $guts );
            }
        }

        foreach ( $elements_args as $code => $format )
        {
            $codeStart = '[' . $code . '';
            $codeEnd = '[/' . $code . ']';
            for ( $lastFound = strpos( $toParse, $codeStart ); $lastFound !== false; $lastFound = @strpos( $toParse, $codeStart, $lastFound + 1 ) )
            {
                if ( $toParse[ $lastFound + strlen( $codeStart ) ] !== '=' )
                {
                    continue;
                }

                $elemEnd = strpos( $toParse, "]", $lastFound );
                if ( $elemEnd === false )
                {
                    return false;
                }

                $endFound = strpos( $toParse, $codeEnd, $lastFound );
                if ( $endFound === false )
                {
                    continue;
                }

                $argStart = $lastFound + strlen( $codeStart );
                $theArg = substr( $toParse, $argStart + 1, $elemEnd - $argStart - 1 );

                $contentsStart = $argStart + 1 + strlen( $theArg ) + 1;
                $contents = substr( $toParse, $contentsStart, $endFound - $contentsStart );

                $guts = str_replace( "___CONTENT___", $contents, $format ); // Couldn't think of a name, ok? :P
                $guts = str_replace( "___ARGUMENT___", $theArg, $guts );
                $replaceEnd = $endFound + strlen( $codeEnd );
                $stuff = substr( $toParse, $lastFound, $replaceEnd - $lastFound );
                $toParse = str_replace( $stuff, $guts, $toParse );
                $lastFound = $lastFound + strlen( $guts );
            }
        }

        foreach ( $elements_nocontent as $code => $format )
        {
            $codeStart = '[' . $code . '';
            for ( $lastFound = strpos( $toParse, $codeStart ); $lastFound !== false; $lastFound = @strpos( $toParse, $codeStart, $lastFound + 1 ) )
            {
                if ( $toParse[ $lastFound + strlen( $codeStart ) ] !== '=' )
                {
                    continue;
                }

                $elemEnd = strpos( $toParse, "]", $lastFound );
                if ( $elemEnd === false )
                {
                    return false;
                }

                $argStart = $lastFound + strlen( $codeStart );
                $theArg = substr( $toParse, $argStart + 1, $elemEnd - $argStart - 1 );

                $guts = str_replace( "___ARGUMENT___", $theArg, $format );
                $replaceEnd = $elemEnd + 1;
                $stuff = substr( $toParse, $lastFound, $replaceEnd - $lastFound );
                $toParse = str_replace( $stuff, $guts, $toParse );
                $lastFound = $lastFound + strlen( $guts );
            }
        }

        $parsedText .= $toParse;
    }

    return $parsedText;
}

?>