<?php rcs_id('$Id: stdlib.php,v 1.81 2002-01-19 09:41:39 carstenklapp Exp $');

/*
  Standard functions for Wiki functionality
    WikiURL($pagename, $args, $get_abs_url)
    StartTag($tag, $args)
    Element($tag, $args, $content)
    QElement($tag, $args, $content)
    IconForLink($protocol_or_url)
    LinkURL($url, $linktext)
    LinkWikiWord($wikiword, $linktext)
    LinkExistingWikiWord($wikiword, $linktext)
    LinkUnknownWikiWord($wikiword, $linktext)
    LinkImage($url, $alt)
    class Stack { push($item), pop(), cnt(), top() }
    CookSpaces($pagearray)
    MakeWikiForm ($pagename, $args, $class, $button_text)
    SplitQueryArgs ($query_args)
    LinkPhpwikiURL($url, $text)
    ParseAndLink($bracketlink)
    ExtractWikiPageLinks($content)
    LinkRelatedPages($dbi, $pagename)
    split_pagename ($page)
    NoSuchRevision ($page, $version)
    TimezoneOffset ($time, $no_colon)
    Iso8601DateTime ($time)
    Rfc2822DateTime ($time)
    CTime ($time)
    __printf ($fmt)
    __sprintf ($fmt)
    __vsprintf ($fmt, $args)

  function moved => LinkInterWikiLink($link, $linktext)
    (see /lib/interwiki.php)
  function gone  => UpdateRecentChanges($dbi, $pagename, $isnewpage) 
    (see /lib/plugin/RecentChanges.php)

*/


function WikiURL($pagename, $args = '', $get_abs_url = false) {
    if (is_array($args)) {
        $enc_args = array();
        foreach  ($args as $key => $val) {
            $enc_args[] = urlencode($key) . '=' . urlencode($val);
        }
        $args = join('&', $enc_args);
    }
    
    if (USE_PATH_INFO) {
        $url = $get_abs_url ? SERVER_URL . VIRTUAL_PATH . "/" : "";
        $url .= rawurlencode($pagename);
        if ($args)
            $url .= "?$args";
    }
    else {
        $url = $get_abs_url ? SERVER_URL . SCRIPT_NAME : basename(SCRIPT_NAME);
        $url .= "?pagename=" . rawurlencode($pagename);
        if ($args)
            $url .= "&$args";
    }
    return $url;
}

define('NO_END_TAG_PAT',
       '/^' . join('|', array('area', 'base', 'basefont',
                              'br', 'col', 'frame',
                              'hr', 'img', 'input',
                              'isindex', 'link', 'meta',
                              'param')) . '$/i');

function StartTag($tag, $args = '') {
    $s = "<$tag";
    if (is_array($args)) {
        while (list($key, $val) = each($args))
            {
                if (is_string($val) || is_numeric($val))
                    $s .= sprintf(' %s="%s"', $key, htmlspecialchars($val));
                else if ($val)
                    $s .= " $key=\"$key\"";
            }
    }
    return "$s>";
}


function Element($tag, $args = '', $content = '') {
    $html = "<$tag";
    if (!is_array($args)) {
        $content = $args;
        $args = false;
    }
    $html = StartTag($tag, $args);
    if (preg_match(NO_END_TAG_PAT, $tag)) {
        assert(! $content);
        return preg_replace('/>$/', " />", $html);
    } else {
        $html .= $content;
        $html .= "</$tag>";//FIXME: newline might not always be desired.
    }
    return $html;
}

function QElement($tag, $args = '', $content = '')
{
    if (is_array($args))
        return Element($tag, $args, htmlspecialchars($content));
    else {
        $content = $args;
        return Element($tag, htmlspecialchars($content));
    }
}

function IconForLink($protocol_or_url) {
    global $Theme;

    list ($proto) = explode(':', $protocol_or_url, 2);
    $src = $Theme->getLinkIconURL($proto);
    if (empty($src))
        return '';
    
    return Element('img', array('src'   => $src,
                                'alt'   => $proto,
                                'class' => 'linkicon'));
}


function LinkURL($url, $linktext = '') {
    // FIXME: Is this needed (or sufficient?)
    if(ereg("[<>\"]", $url)) {
        return Element('strong',
                       QElement('u', array('class' => 'baduri'),
                                _("BAD URL -- remove all of <, >, \"")));
    }
    
    $attr['href'] = $url;
    
    if (empty($linktext)) {
        $linktext = $url;
        $attr['class'] = 'rawurl';
    } else
        $attr['class'] = 'namedurl';
    
    return Element('a', $attr,
                   IconForLink($url) . htmlspecialchars($linktext));
}

function LinkWikiWord($wikiword, $linktext = '', $version = false) {
    global $dbi;
    if ($dbi->isWikiPage($wikiword))
        return LinkExistingWikiWord($wikiword, $linktext);
    else
        return LinkUnknownWikiWord($wikiword, $linktext);
}

function LinkExistingWikiWord($wikiword, $linktext = '', $version = false) {
    if (empty($linktext)) {
        $linktext = $wikiword;
        if (defined("autosplit_wikiwords"))
            $linktext = split_pagename($linktext);
        $class = 'wiki';
    }
    else
        $class = 'named-wiki';

    $attr = array();
    if ($version !== false)
        $attr['version'] = $version;

    return QElement('a', array('href'  => WikiURL($wikiword, $attr),
                               'class' => $class),
                    $linktext);
}

function LinkUnknownWikiWord($wikiword, $linktext = '', $version = false) {
    if (empty($linktext)) {
        $linktext = $wikiword;
        if (defined("autosplit_wikiwords"))
            $linktext=split_pagename($linktext);
        $class = 'wikiunknown';
    } else
        $class = 'named-wikiunknown';
    
    $attr = array('action' => 'edit');
    if ($version !== false)
        $attr['version'] = $version;

    //FIXME: do this without global
    global $Theme;
    // Note: $qmark uses Element instead of QElement to allow html in the WikiMark.
    $qmark = Element('a', array('href' => WikiURL($wikiword, $attr)),
                      $Theme->getWikiMark());

    // FIXME: for some reason sprintf wants 4 arguments here!?
    // lib/stdlib.php:196: Warning[2]: sprintf(): too few arguments
    //$html = sprintf($qmark,$text,"","");

    // FIXME: Sorry, this ugly hack is to prevent whole word from being inverted.
    // For now this is necessary to use the new $Theme->setWikiMark("?%s")
    $html = @ sprintf($qmark, "</span>".Element('u', $linktext)."<span>");

    return Element('span', array('class' => $class), $html);
}

function LinkImage($url, $alt = '[External Image]') {
    // FIXME: Is this needed (or sufficient?)
    //  As long as the src in htmlspecialchars()ed I think it's safe.
    if(ereg("[<>\"]", $url)) {
        return Element('strong',
                       QElement('u', array('class' => 'baduri'),
                                _("BAD URL -- remove all of <, >, \"")));
    }
    return Element('img', array('src' => $url, 'alt' => $alt));
}

// converts spaces to tabs
function CookSpaces($pagearray) {
    return preg_replace("/ {3,8}/", "\t", $pagearray);
}


class Stack {
    var $items = array();
    var $size = 0;
    
    function push($item) {
        $this->items[$this->size] = $item;
        $this->size++;
        return true;
    }  
    
    function pop() {
        if ($this->size == 0) {
            return false; // stack is empty
        }  
        $this->size--;
        return $this->items[$this->size];
    }  
    
    function cnt() {
        return $this->size;
    }  
    
    function top() {
        if($this->size)
            return $this->items[$this->size - 1];
        else
            return '';
    }
    
}  
// end class definition


function MakeWikiForm ($pagename, $args, $class, $button_text = '') {
    $formargs['action'] = USE_PATH_INFO ? WikiURL($pagename) : SCRIPT_NAME;
    $formargs['method'] = 'get';
    $formargs['class']  = $class;
    
    $contents = '';
    $input_seen = 0;
    
    while (list($key, $val) = each($args)) {
        $a = array('name' => $key, 'value' => $val, 'type' => 'hidden');
        
        if (preg_match('/^ (\d*) \( (.*) \) ((upload)?) $/xi', $val, $m)) {
            $input_seen++;
            $a['type'] = 'text';
            $a['size'] = $m[1] ? $m[1] : 30;
            $a['value'] = $m[2];
            if ($m[3])
                {
                    $a['type'] = 'file';
                    $formargs['enctype'] = 'multipart/form-data';
                    $contents .= Element('input',
                                         array('name'  => 'MAX_FILE_SIZE',
                                               'value' =>  MAX_UPLOAD_SIZE,
                                               'type'  => 'hidden'));
                    $formargs['method'] = 'post';
                }
        }
        
        $contents .= Element('input', $a);
    }
    
    $row = Element('td', $contents);
    
    if (!empty($button_text)) {
        $row .= Element('td',
                        Element('input', array('type'  => 'submit',
                                               'class' => 'button',
                                               'value' => $button_text)));
    }
    
    return Element('form', $formargs,
                   Element('table', array('cellspacing' => 0,
                                          'cellpadding' => 2,
                                          'border'      => 0),
                           Element('tr', $row)));
}

function SplitQueryArgs ($query_args = '') 
{
    $split_args = split('&', $query_args);
    $args = array();
    while (list($key, $val) = each($split_args))
        if (preg_match('/^ ([^=]+) =? (.*) /x', $val, $m))
            $args[$m[1]] = $m[2];
    return $args;
}

function LinkPhpwikiURL($url, $text = '') {
    $args = array();
    
    if (!preg_match('/^ phpwiki: ([^?]*) [?]? (.*) $/x', $url, $m))
        return Element('strong',
                       QElement('u', array('class' => 'baduri'),
                                'BAD phpwiki: URL'));
    if ($m[1])
        $pagename = urldecode($m[1]);
    $qargs = $m[2];
    
    if (empty($pagename) &&
        preg_match('/^(diff|edit|links|info)=([^&]+)$/', $qargs, $m))
        {
            // Convert old style links (to not break diff links in
            // RecentChanges).
            $pagename = urldecode($m[2]);
            $args = array("action" => $m[1]);
        }
    else {
        $args = SplitQueryArgs($qargs);
    }
    
    if (empty($pagename))
        $pagename = $GLOBALS['pagename'];
    
    if (isset($args['action']) && $args['action'] == 'browse')
        unset($args['action']);
    /*FIXME:
      if (empty($args['action']))
      $class = 'wikilink';
      else if (is_safe_action($args['action']))
      $class = 'wikiaction';
    */
    if (empty($args['action']) || is_safe_action($args['action']))
        $class = 'wikiaction';
    else {
        // Don't allow administrative links on unlocked pages.
        // FIXME: Ugh: don't like this...
        global $dbi;
        $page = $dbi->getPage($GLOBALS['pagename']);
        if (!$page->get('locked'))
            return QElement('u', array('class' => 'wikiunsafe'),
                            _("Lock page to enable link"));
        
        $class = 'wikiadmin';
    }
    
    // FIXME: ug, don't like this
    if (preg_match('/=\d*\(/', $qargs))
        return MakeWikiForm($pagename, $args, $class, $text);
    if ($text)
        $text = htmlspecialchars($text);
    else
        $text = QElement('span', array('class' => 'rawurl'), $url);
    
    return Element('a', array('href'  => WikiURL($pagename, $args),
                              'class' => $class),
                   $text);
}

function ParseAndLink($bracketlink) {
    global $dbi, $AllowedProtocols, $InlineImages;
    global $InterWikiLinkRegexp;
    
    // $bracketlink will start and end with brackets; in between will
    // be either a page name, a URL or both separated by a pipe.
    
    // strip brackets and leading space
    preg_match("/(\[\s*)(.+?)(\s*\])/", $bracketlink, $match);
    // match the contents 
    preg_match("/([^|]+)(\|)?([^|]+)?/", $match[2], $matches);
    
    if (isset($matches[3])) {
        // named link of the form  "[some link name | http://blippy.com/]"
        $URL = trim($matches[3]);
        $linkname = trim($matches[1]);
          $linktype = 'named';
    } else {
        // unnamed link of the form "[http://blippy.com/] or [wiki page]"
        $URL = trim($matches[1]);
        $linkname = '';
        $linktype = 'simple';
    }
    
    if ($dbi->isWikiPage($URL)) {
        $link['type'] = "wiki-$linktype";
        $link['link'] = LinkExistingWikiWord($URL, $linkname);
    } elseif (preg_match("#^($AllowedProtocols):#", $URL)) {
        // if it's an image, embed it; otherwise, it's a regular link
        if (preg_match("/($InlineImages)$/i", $URL)) {
            $link['type'] = "image-$linktype";
              $link['link'] = LinkImage($URL, $linkname);
        } else {
            $link['type'] = "url-$linktype";
            $link['link'] = LinkURL($URL, $linkname);
        }
    } elseif (preg_match("#^phpwiki:(.*)#", $URL, $match)) {
        $link['type'] = "url-wiki-$linktype";
        $link['link'] = LinkPhpwikiURL($URL, $linkname);
    } elseif (preg_match("#^\d+$#", $URL)) {
        $link['type'] = "footnote-$linktype";
        $link['link'] = $URL;
    } elseif (function_exists('LinkInterWikiLink') &&
              preg_match("#^$InterWikiLinkRegexp:#", $URL)) {
          $link['type'] = "interwiki-$linktype";
          $link['link'] = LinkInterWikiLink($URL, $linkname);
      } else {
          $link['type'] = "wiki-unknown-$linktype";
          $link['link'] = LinkUnknownWikiWord($URL, $linkname);
      }
    
    return $link;
}


function ExtractWikiPageLinks($content) {
    global $WikiNameRegexp;
    
    if (is_string($content))
        $content = explode("\n", $content);
    
    $wikilinks = array();
    foreach ($content as $line) {
        // remove plugin code
        $line = preg_replace('/<\?plugin\s+\w.*?\?>/', '', $line);
        // remove escaped '['
        $line = str_replace('[[', ' ', $line);
        
        // bracket links (only type wiki-* is of interest)
        $numBracketLinks = preg_match_all("/\[\s*([^\]|]+\|)?\s*(\S.*?)\s*\]/",
                                          $line, $brktlinks);
        for ($i = 0; $i < $numBracketLinks; $i++) {
            $link = ParseAndLink($brktlinks[0][$i]);
            if (preg_match("#^wiki#", $link['type']))
                $wikilinks[$brktlinks[2][$i]] = 1;
            
            $brktlink = preg_quote($brktlinks[0][$i]);
            $line = preg_replace("|$brktlink|", '', $line);
        }
        
        // BumpyText old-style wiki links
        if (preg_match_all("/!?$WikiNameRegexp/", $line, $link)) {
            for ($i = 0; isset($link[0][$i]); $i++) {
                if($link[0][$i][0] <> '!')
                    $wikilinks[$link[0][$i]] = 1;
            }
        }
    }
    return array_keys($wikilinks);
}      

function LinkRelatedPages($dbi, $pagename)
{
    // currently not supported everywhere
    if(!function_exists('GetWikiPageLinks'))
        return '';
    
    //FIXME: fix or toss?
    $links = GetWikiPageLinks($dbi, $pagename);
    
    $txt = QElement('strong',
                    sprintf (_("%d best incoming links:"), NUM_RELATED_PAGES));
    for($i = 0; $i < NUM_RELATED_PAGES; $i++) {
        if(isset($links['in'][$i])) {
            list($name, $score) = $links['in'][$i];
            $txt .= LinkExistingWikiWord($name) . " ($score), ";
        }
    }
    
    $txt .= "\n" . Element('br');
    $txt .= Element('strong',
                    sprintf (_("%d best outgoing links:"), NUM_RELATED_PAGES));
    for($i = 0; $i < NUM_RELATED_PAGES; $i++) {
        if(isset($links['out'][$i])) {
            list($name, $score) = $links['out'][$i];
        if($dbi->isWikiPage($name))
                $txt .= LinkExistingWikiWord($name) . " ($score), ";
        }
    }
    
    $txt .= "\n" . Element('br');
    $txt .= Element('strong',
                    sprintf (_("%d most popular nearby:"), NUM_RELATED_PAGES));
    for($i = 0; $i < NUM_RELATED_PAGES; $i++) {
        if(isset($links['popular'][$i])) {
            list($name, $score) = $links['popular'][$i];
        $txt .= LinkExistingWikiWord($name) . " ($score), ";
        }
    }
    
    return $txt;
}


/**
 * Split WikiWords in page names.
 *
 * It has been deemed useful to split WikiWords (into "Wiki Words") in
 * places like page titles. This is rumored to help search engines
 * quite a bit.
 *
 * @param $page string The page name.
 *
 * @return string The split name.
 */
function split_pagename ($page) {
    
    if (preg_match("/\s/", $page))
        return $page;           // Already split --- don't split any more.
    
    // FIXME: this algorithm is Anglo-centric.
    static $RE;
    if (!isset($RE)) {
        // This mess splits between a lower-case letter followed by
        // either an upper-case or a numeral; except that it wont
        // split the prefixes 'Mc', 'De', or 'Di' off of their tails.
        $RE[] = '/([[:lower:]])((?<!Mc|De|Di)[[:upper:]]|\d)/';
        // This the single-letter words 'I' and 'A' from any following
        // capitalized words.
        $RE[] = '/(?: |^)([AI])([[:upper:]][[:lower:]])/';
        // Split numerals from following letters.
        $RE[] = '/(\d)([[:alpha:]])/';
        
        foreach ($RE as $key => $val)
            $RE[$key] = pcre_fix_posix_classes($val);
    }
    
    foreach ($RE as $regexp)
        $page = preg_replace($regexp, '\\1 \\2', $page);
    return $page;
}

function NoSuchRevision ($page, $version) {
    $html = Element('p', QElement('strong', gettext("Bad Version"))) . "\n";
    $html .= QElement('p',
                      sprintf(_("I'm sorry.  Version %d of %s is not in my database."),
                              $version, $page->getName())) . "\n";
    
    include_once('lib/Template.php');
    echo GeneratePage('MESSAGE', $html, _("Bad Version"));
    ExitWiki ("");
}


/**
 * Get time offset for local time zone.
 *
 * @param $time time_t Get offset for this time. Default: now.
 * @param $no_colon boolean Don't put colon between hours and minutes.
 * @return string Offset as a string in the format +HH:MM.
 */
function TimezoneOffset ($time = false, $no_colon = false) {
    if ($time === false)
        $time = time();
    $secs = date('Z', $time);
    if ($secs < 0) {
        $sign = '-';
        $secs = -$secs;
    }
    else {
        $sign = '+';
    }
    $colon = $no_colon ? '' : ':';
    $mins = intval(($secs + 30) / 60);
    return sprintf("%s%02d%s%02d",
                   $sign, $mins / 60, $colon, $mins % 60);
}

/**
 * Format time in ISO-8601 format.
 *
 * @param $time time_t Time.  Default: now.
 * @return string Date and time in ISO-8601 format.
 */
function Iso8601DateTime ($time = false) {
    if ($time === false)
        $time = time();
    $tzoff = TimezoneOffset($time);
    $date  = date('Y-m-d', $time);
    $time  = date('H:i:s', $time);
    return $date . 'T' . $time . $tzoff;
}

/**
 * Format time in RFC-2822 format.
 *
 * @param $time time_t Time.  Default: now.
 * @return string Date and time in RFC-2822 format.
 */
function Rfc2822DateTime ($time = false) {
    if ($time === false)
        $time = time();
    return date('D, j M Y H:i:s ', $time) . TimezoneOffset($time, 'no colon');
}

/**
 * Format time to standard 'ctime' format.
 *
 * @param $time time_t Time.  Default: now.
 * @return string Date and time in RFC-2822 format.
 */
function CTime ($time = false)
{
    if ($time === false)
        $time = time();
    return date("D M j H:i:s Y", $time);
}


/**
 * Internationalized printf.
 *
 * This is essentially the same as PHP's built-in printf
 * with the following exceptions:
 * <ol>
 * <li> It passes the format string through gettext().
 * <li> It supports the argument reordering extensions.
 * </ol>
 *
 * Example:
 *
 * In php code, use:
 * <pre>
 *    __printf("Differences between versions %s and %s of %s",
 *             $new_link, $old_link, $page_link);
 * </pre>
 *
 * Then in locale/po/de.po, one can reorder the printf arguments:
 *
 * <pre>
 *    msgid "Differences between %s and %s of %s."
 *    msgstr "Der Unterschiedsergebnis von %3$s, zwischen %1$s und %2$s."
 * </pre>
 *
 * (Note that while PHP tries to expand $vars within double-quotes,
 * the values in msgstr undergo no such expansion, so the '$'s
 * okay...)
 *
 * One shouldn't use reordered arguments in the default format string.
 * Backslashes in the default string would be necessary to escape the
 * '$'s, and they'll cause all kinds of trouble....
 */ 
function __printf ($fmt) {
    $args = func_get_args();
    array_shift($args);
    echo __vsprintf($fmt, $args);
}

/**
 * Internationalized sprintf.
 *
 * This is essentially the same as PHP's built-in printf with the
 * following exceptions:
 *
 * <ol>
 * <li> It passes the format string through gettext().
 * <li> It supports the argument reordering extensions.
 * </ol>
 *
 * @see __printf
 */ 
function __sprintf ($fmt) {
    $args = func_get_args();
    array_shift($args);
    return __vsprintf($fmt, $args);
}

/**
 * Internationalized vsprintf.
 *
 * This is essentially the same as PHP's built-in printf with the
 * following exceptions:
 *
 * <ol>
 * <li> It passes the format string through gettext().
 * <li> It supports the argument reordering extensions.
 * </ol>
 *
 * @see __printf
 */ 
function __vsprintf ($fmt, $args) {
    $fmt = gettext($fmt);
    // PHP's sprintf doesn't support variable with specifiers,
    // like sprintf("%*s", 10, "x"); --- so we won't either.
    
    if (preg_match_all('/(?<!%)%(\d+)\$/x', $fmt, $m)) {
        // Format string has '%2$s' style argument reordering.
        // PHP doesn't support this.
        if (preg_match('/(?<!%)%[- ]?\d*[^- \d$]/x', $fmt))
            // literal variable name substitution only to keep locale
            // strings uncluttered
            trigger_error(sprintf(_("Can't mix '%s' with '%s' type format strings"),
                                  '%1\$s','%s'), E_USER_WARNING);
        
        $fmt = preg_replace('/(?<!%)%\d+\$/x', '%', $fmt);
        $newargs = array();
        
        // Reorder arguments appropriately.
        foreach($m[1] as $argnum) {
            if ($argnum < 1 || $argnum > count($args))
                trigger_error(sprintf(_("%s: argument index out of range"), 
                                      $argnum), E_USER_WARNING);
            $newargs[] = $args[$argnum - 1];
        }
        $args = $newargs;
    }
    
    // Not all PHP's have vsprintf, so...
    array_unshift($args, $fmt);
    return call_user_func_array('sprintf', $args);
}


// Class introspections

/** Determine whether object is of a specified type.
 *
 * @param $object object An object.
 * @param $class string Class name.
 * @return bool True iff $object is a $class
 * or a sub-type of $class. 
 */
function isa ($object, $class) 
{
    $lclass = strtolower($class);

    return get_class($object) == strtolower($lclass)
        || is_subclass_of($object, $lclass);
}

// (c-file-style: "gnu")
// Local Variables:
// mode: php
// tab-width: 8
// c-basic-offset: 4
// c-hanging-comment-ender-p: nil
// indent-tabs-mode: nil
// End:   
?>