<?php
# Global functions used everywhere

$wgNumberOfArticles = -1; # Unset
$wgTotalViews = -1;
$wgTotalEdits = -1;

include_once( "DatabaseFunctions.php" );
include_once( "UpdateClasses.php" );
include_once( "LogPage.php" );

/*
 * Compatibility functions
 */

# PHP <4.3.x is not actively supported; 4.1.x and 4.2.x might or might not work.
# <4.1.x will not work, as we use a number of features introduced in 4.1.0
# such as the new autoglobals.

if( !function_exists('iconv') ) {
	# iconv support is not in the default configuration and so may not be present.
	# Assume will only ever use utf-8 and iso-8859-1.
	# This will *not* work in all circumstances.
	function iconv( $from, $to, $string ) {
		if(strcasecmp( $from, $to ) == 0) return $string;
		if(strcasecmp( $from, "utf-8" ) == 0) return utf8_decode( $string );
		if(strcasecmp( $to, "utf-8" ) == 0) return utf8_encode( $string );
		return $string;
	}
}

if( !function_exists('file_get_contents') ) {
	# Exists in PHP 4.3.0+
	function file_get_contents( $filename ) {
		return implode( "", file( $filename ) );
	}
}

$wgRandomSeeded = false;

function wfSeedRandom()
{
	global $wgRandomSeeded;

	if ( ! $wgRandomSeeded ) {
		$seed = hexdec(substr(md5(microtime()),-8)) & 0x7fffffff;
		mt_srand( $seed );
		$wgRandomSeeded = true;
	}
}

# Generates a URL from a URL-encoded title and a query string
# Title::getLocalURL() is preferred in most cases
#
function wfLocalUrl( $a, $q = "" )
{
	global $wgServer, $wgScript, $wgArticlePath;

	$a = str_replace( " ", "_", $a );

	if ( "" == $a ) {
		if( "" == $q ) {
			$a = $wgScript;
		} else {
			$a = "{$wgScript}?{$q}";
		}	
	} else if ( "" == $q ) {
		$a = str_replace( "$1", $a, $wgArticlePath );
	} else if ($wgScript != '' ) {
		$a = "{$wgScript}?title={$a}&{$q}";	
	} else { //XXX ugly hack for toplevel wikis
		$a = "/{$a}&{$q}";	
	}
	return $a;
}

function wfLocalUrlE( $a, $q = "" )
{
	return wfEscapeHTML( wfLocalUrl( $a, $q ) );
	# die( "Call to obsolete function wfLocalUrlE()" );
}

function wfFullUrl( $a, $q = "" ) {
	wfDebugDieBacktrace( "Call to obsolete function wfFullUrl(); use Title::getFullURL" );
}

function wfFullUrlE( $a, $q = "" ) {
	wfDebugDieBacktrace( "Call to obsolete function wfFullUrlE(); use Title::getFullUrlE" );

}

function wfImageUrl( $img )
{
	global $wgUploadPath;

	$nt = Title::newFromText( $img );
	if( !$nt ) return "";

	$name = $nt->getDBkey();
	$hash = md5( $name );

	$url = "{$wgUploadPath}/" . $hash{0} . "/" .
	  substr( $hash, 0, 2 ) . "/{$name}";
	return wfUrlencode( $url );
}

function wfImagePath( $img )
{
	global $wgUploadDirectory;

	$nt = Title::newFromText( $img );
	if( !$nt ) return "";

	$name = $nt->getDBkey();
	$hash = md5( $name );

	$path = "{$wgUploadDirectory}/" . $hash{0} . "/" .
	  substr( $hash, 0, 2 ) . "/{$name}";
	return $path;
}

function wfThumbUrl( $img )
{
	global $wgUploadPath;

	$nt = Title::newFromText( $img );
	if( !$nt ) return "";

	$name = $nt->getDBkey();
	$hash = md5( $name );

	$url = "{$wgUploadPath}/thumb/" . $hash{0} . "/" .
	  substr( $hash, 0, 2 ) . "/{$name}";
	return wfUrlencode( $url );
}


function wfImageThumbUrl( $name, $subdir="thumb" )
{
	global $wgUploadPath;

	$hash = md5( $name );
	$url = "{$wgUploadPath}/{$subdir}/" . $hash{0} . "/" .
	  substr( $hash, 0, 2 ) . "/{$name}";
	return wfUrlencode($url);
}

function wfImageArchiveUrl( $name )
{
	global $wgUploadPath;

	$hash = md5( substr( $name, 15) );
	$url = "{$wgUploadPath}/archive/" . $hash{0} . "/" .
	  substr( $hash, 0, 2 ) . "/{$name}";
	return wfUrlencode($url);
}

function wfUrlencode ( $s )
{
	$s = urlencode( $s );
	$s = preg_replace( "/%3[Aa]/", ":", $s );
	$s = preg_replace( "/%2[Ff]/", "/", $s );

	return $s;
}

function wfUtf8Sequence($codepoint) {
	if($codepoint <     0x80) return chr($codepoint);
	if($codepoint <    0x800) return chr($codepoint >>  6 & 0x3f | 0xc0) .
                                     chr($codepoint       & 0x3f | 0x80);
    if($codepoint <  0x10000) return chr($codepoint >> 12 & 0x0f | 0xe0) .
                                     chr($codepoint >>  6 & 0x3f | 0x80) .
                                     chr($codepoint       & 0x3f | 0x80);
	if($codepoint < 0x100000) return chr($codepoint >> 18 & 0x07 | 0xf0) . # Double-check this
	                                 chr($codepoint >> 12 & 0x3f | 0x80) .
                                     chr($codepoint >>  6 & 0x3f | 0x80) .
                                     chr($codepoint       & 0x3f | 0x80);
	# Doesn't yet handle outside the BMP
	return "&#$codepoint;";
}

function wfMungeToUtf8($string) {
	global $wgInputEncoding; # This is debatable
	#$string = iconv($wgInputEncoding, "UTF-8", $string);
	$string = preg_replace ( '/&#([0-9]+);/e', 'wfUtf8Sequence($1)', $string );
	$string = preg_replace ( '/&#x([0-9a-f]+);/ie', 'wfUtf8Sequence(0x$1)', $string );
	# Should also do named entities here
	return $string;
}

function wfDebug( $text, $logonly = false )
{
	global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly;

	if ( isset( $wgOut ) && $wgDebugComments && !$logonly ) {
		$wgOut->debug( $text );
	}
	if ( "" != $wgDebugLogFile && !$wgProfileOnly ) {
		error_log( $text, 3, $wgDebugLogFile );
	}
}

function logProfilingData()
{
	global $wgRequestTime, $wgDebugLogFile;
	global $wgProfiling, $wgProfileStack, $wgProfileLimit, $wgUser;
	$now = wfTime();

	list( $usec, $sec ) = explode( " ", $wgRequestTime );
	$start = (float)$sec + (float)$usec;
	$elapsed = $now - $start;
	if ( "" != $wgDebugLogFile ) {
		$prof = wfGetProfilingOutput( $start, $elapsed );
		$forward = "";
		if( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) )
			$forward = " forwarded for " . $_SERVER['HTTP_X_FORWARDED_FOR'];
		if( !empty( $_SERVER['HTTP_CLIENT_IP'] ) )
			$forward .= " client IP " . $_SERVER['HTTP_CLIENT_IP'];
		if( !empty( $_SERVER['HTTP_FROM'] ) )
			$forward .= " from " . $_SERVER['HTTP_FROM'];
		if( $forward )
			$forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
		if($wgUser->getId() == 0)
			$forward .= " anon";
		$log = sprintf( "%s\t%04.3f\t%s\n",
		  gmdate( "YmdHis" ), $elapsed,
		  urldecode( $_SERVER['REQUEST_URI'] . $forward ) );
		error_log( $log . $prof, 3, $wgDebugLogFile );
	}
}


function wfReadOnly()
{
	global $wgReadOnlyFile;

	if ( "" == $wgReadOnlyFile ) { return false; }
	return is_file( $wgReadOnlyFile );
}

$wgReplacementKeys = array( "$1", "$2", "$3", "$4", "$5", "$6", "$7", "$8", "$9" );

# Get a message from anywhere
function wfMsg( $key ) {
	$args = func_get_args();
	if ( count( $args ) ) {
		array_shift( $args );
	}
	return wfMsgReal( $key, $args, true );
}

# Get a message from the language file
function wfMsgNoDB( $key ) {
	$args = func_get_args();
	if ( count( $args ) ) {
		array_shift( $args );
	}
	return wfMsgReal( $key, $args, false );
}

# Really get a message
function wfMsgReal( $key, $args, $useDB ) {
	global $wgReplacementKeys, $wgMessageCache, $wgLang;

	$fname = "wfMsg";
	wfProfileIn( $fname );
	if ( $wgMessageCache ) {
		$message = $wgMessageCache->get( $key, $useDB );
	} elseif ( $wgLang ) {
		$message = $wgLang->getMessage( $key );
	} else {
		wfDebug( "No language object when getting $key\n" );
		$message = "&lt;$key&gt;";
	}

	# Replace arguments
	if( count( $args ) ) {
		$message = str_replace( $wgReplacementKeys, $args, $message );
	}
	wfProfileOut( $fname );
	return $message;
}

function wfCleanFormFields( $fields )
{
	wfDebugDieBacktrace( "Call to obsolete wfCleanFormFields(). Use wgRequest instead..." );
}

function wfMungeQuotes( $in )
{
	$out = str_replace( "%", "%25", $in );
	$out = str_replace( "'", "%27", $out );
	$out = str_replace( "\"", "%22", $out );
	return $out;
}

function wfDemungeQuotes( $in )
{
	$out = str_replace( "%22", "\"", $in );
	$out = str_replace( "%27", "'", $out );
	$out = str_replace( "%25", "%", $out );
	return $out;
}

function wfCleanQueryVar( $var )
{
	wfDebugDieBacktrace( "Call to obsolete function wfCleanQueryVar(); use wgRequest instead" );
}

function wfSpecialPage()
{
	global $wgUser, $wgOut, $wgTitle, $wgLang;

	/* FIXME: this list probably shouldn't be language-specific, per se */
	$validSP = $wgLang->getValidSpecialPages();
	$sysopSP = $wgLang->getSysopSpecialPages();
	$devSP = $wgLang->getDeveloperSpecialPages();

	$wgOut->setArticleRelated( false );
	$wgOut->setRobotpolicy( "noindex,follow" );

	$bits = split( "/", $wgTitle->getDBkey(), 2 );
	$t = $bits[0];
	if( empty( $bits[1] ) ) {
		$par = NULL;
	} else {
		$par = $bits[1];
	}

	if ( array_key_exists( $t, $validSP ) ||
	  ( $wgUser->isSysop() && array_key_exists( $t, $sysopSP ) ) ||
	  ( $wgUser->isDeveloper() && array_key_exists( $t, $devSP ) ) ) {
	  	if($par !== NULL)
			$wgTitle = Title::makeTitle( Namespace::getSpecial(), $t );

		$wgOut->setPageTitle( wfMsg( strtolower( $wgTitle->getText() ) ) );

		$inc = "Special" . $t . ".php";
		include_once( $inc );
		$call = "wfSpecial" . $t;
		$call( $par );
	} else if ( array_key_exists( $t, $sysopSP ) ) {
		$wgOut->sysopRequired();
	} else if ( array_key_exists( $t, $devSP ) ) {
		$wgOut->developerRequired();
	} else {
		$wgOut->errorpage( "nosuchspecialpage", "nospecialpagetext" );
	}
}

function wfSearch( $s )
{
	$se = new SearchEngine( $s );
	$se->showResults();
}

function wfGo( $s )
{ # pick the nearest match
	$se = new SearchEngine( $s );
	$se->goResult();
}

# Just like exit() but makes a note of it.
function wfAbruptExit(){
	static $called = false;
	if ( $called ){
		exit();
	}
	$called = true;

	if( function_exists( "debug_backtrace" ) ){ // PHP >= 4.3
		$bt = debug_backtrace();
		for($i = 0; $i < count($bt) ; $i++){
			$file = $bt[$i]["file"];
			$line = $bt[$i]["line"];
			wfDebug("WARNING: Abrupt exit in $file at line $line\n");
		}
	} else { 
		wfDebug("WARNING: Abrupt exit\n");
	}
	exit();
}

function wfDebugDieBacktrace( $msg = "" ) {
	$msg .= "\n<p>Backtrace:</p>\n<ul>\n";
	$backtrace = debug_backtrace();
	foreach( $backtrace as $call ) {
		$f = explode( DIRECTORY_SEPARATOR, $call['file'] );
		$file = $f[count($f)-1];
		$msg .= "<li>" . $file . " line " . $call['line'] . ", in ";
		if( !empty( $call['class'] ) ) $msg .= $call['class'] . "::";
		$msg .= $call['function'] . "()</li>\n";
	}
	die( $msg );
}

function wfNumberOfArticles()
{
	global $wgNumberOfArticles;

	wfLoadSiteStats();
	return $wgNumberOfArticles;
}

/* private */ function wfLoadSiteStats()
{
	global $wgNumberOfArticles, $wgTotalViews, $wgTotalEdits;
	if ( -1 != $wgNumberOfArticles ) return;

	$sql = "SELECT ss_total_views, ss_total_edits, ss_good_articles " .
	  "FROM site_stats WHERE ss_row_id=1";
	$res = wfQuery( $sql, DB_READ, "wfLoadSiteStats" );

	if ( 0 == wfNumRows( $res ) ) { return; }
	else {
		$s = wfFetchObject( $res );
		$wgTotalViews = $s->ss_total_views;
		$wgTotalEdits = $s->ss_total_edits;
		$wgNumberOfArticles = $s->ss_good_articles;
	}
}

function wfEscapeHTML( $in )
{
	return str_replace(
		array( "&", "\"", ">", "<" ),
		array( "&amp;", "&quot;", "&gt;", "&lt;" ),
		$in );
}

function wfEscapeHTMLTagsOnly( $in ) {
	return str_replace(
		array( "\"", ">", "<" ),
		array( "&quot;", "&gt;", "&lt;" ),
		$in );
}

function wfUnescapeHTML( $in )
{
	$in = str_replace( "&lt;", "<", $in );
	$in = str_replace( "&gt;", ">", $in );
	$in = str_replace( "&quot;", "\"", $in );
	$in = str_replace( "&amp;", "&", $in );
	return $in;
}

function wfImageDir( $fname )
{
	global $wgUploadDirectory;

	$hash = md5( $fname );
	$oldumask = umask(0);
	$dest = $wgUploadDirectory . "/" . $hash{0};
	if ( ! is_dir( $dest ) ) { mkdir( $dest, 0777 ); }
	$dest .= "/" . substr( $hash, 0, 2 );
	if ( ! is_dir( $dest ) ) { mkdir( $dest, 0777 ); }
	
	umask( $oldumask );
	return $dest;
}

function wfImageThumbDir( $fname , $subdir="thumb")
{
	return wfImageArchiveDir( $fname, $subdir );
}

function wfImageArchiveDir( $fname , $subdir="archive")
{
	global $wgUploadDirectory;

	$hash = md5( $fname );
	$oldumask = umask(0);
	$archive = "{$wgUploadDirectory}/{$subdir}";
	if ( ! is_dir( $archive ) ) { mkdir( $archive, 0777 ); }
	$archive .= "/" . $hash{0};
	if ( ! is_dir( $archive ) ) { mkdir( $archive, 0777 ); }
	$archive .= "/" . substr( $hash, 0, 2 );
	if ( ! is_dir( $archive ) ) { mkdir( $archive, 0777 ); }

	umask( $oldumask );
	return $archive;
}

function wfRecordUpload( $name, $oldver, $size, $desc, $copyStatus = "", $source = "" )
{
	global $wgUser, $wgLang, $wgTitle, $wgOut, $wgDeferredUpdateList;
	global $wgUseCopyrightUpload; 
	
	$fname = "wfRecordUpload";

	$sql = "SELECT img_name,img_size,img_timestamp,img_description,img_user," .
	  "img_user_text FROM image WHERE img_name='" . wfStrencode( $name ) . "'";
	$res = wfQuery( $sql, DB_READ, $fname );

	$now = wfTimestampNow();
	$won = wfInvertTimestamp( $now );
	$size = IntVal( $size );
	
	if ( $wgUseCopyrightUpload )
	  {
	    $textdesc = "== " . wfMsg ( "filedesc" ) . " ==\n" . $desc . "\n" .
	      "== " . wfMsg ( "filestatus" ) . " ==\n" . $copyStatus . "\n" .
	      "== " . wfMsg ( "filesource" ) . " ==\n" . $source ;
	  }
	else $textdesc = $desc ;

	$now = wfTimestampNow();
	$won = wfInvertTimestamp( $now );
	
	if ( 0 == wfNumRows( $res ) ) {
		$sql = "INSERT INTO image (img_name,img_size,img_timestamp," .
		  "img_description,img_user,img_user_text) VALUES ('" .
		  wfStrencode( $name ) . "',$size,'{$now}','" .
		  wfStrencode( $desc ) . "', '" . $wgUser->getID() .
		  "', '" . wfStrencode( $wgUser->getName() ) . "')";
		wfQuery( $sql, DB_WRITE, $fname );

		$sql = "SELECT cur_id,cur_text FROM cur WHERE cur_namespace=" .
		  Namespace::getImage() . " AND cur_title='" .
		  wfStrencode( $name ) . "'";
		$res = wfQuery( $sql, DB_READ, $fname );
		if ( 0 == wfNumRows( $res ) ) {
            $common =
			  Namespace::getImage() . ",'" .
			  wfStrencode( $name ) . "','" .
			  wfStrencode( $desc ) . "','" . $wgUser->getID() . "','" .
			  wfStrencode( $wgUser->getName() ) . "','" . $now .
			  "',1";
			$sql = "INSERT INTO cur (cur_namespace,cur_title," .
			  "cur_comment,cur_user,cur_user_text,cur_timestamp,cur_is_new," .
			  "cur_text,inverse_timestamp,cur_touched) VALUES (" .
			  $common .
			  ",'" . wfStrencode( $textdesc ) . "','{$won}','{$now}')";
			wfQuery( $sql, DB_WRITE, $fname );
			$id = wfInsertId() or 0; # We should throw an error instead
			
			$titleObj = Title::makeTitle( NS_IMAGE, $name );
			RecentChange::notifyNew( $now, $titleObj, 0, $wgUser, $desc );
			
			$u = new SearchUpdate( $id, $name, $desc );
			$u->doUpdate();
		}
	} else {
		$s = wfFetchObject( $res );

		$sql = "INSERT INTO oldimage (oi_name,oi_archive_name,oi_size," .
		  "oi_timestamp,oi_description,oi_user,oi_user_text) VALUES ('" .
		  wfStrencode( $s->img_name ) . "','" .
		  wfStrencode( $oldver ) .
		  "',{$s->img_size},'{$s->img_timestamp}','" .
		  wfStrencode( $s->img_description ) . "','" .
		  wfStrencode( $s->img_user ) . "','" .
		  wfStrencode( $s->img_user_text) . "')";
		wfQuery( $sql, DB_WRITE, $fname );

		$sql = "UPDATE image SET img_size={$size}," .
		  "img_timestamp='" . wfTimestampNow() . "',img_user='" .
		  $wgUser->getID() . "',img_user_text='" .
		  wfStrencode( $wgUser->getName() ) . "', img_description='" .
		  wfStrencode( $desc ) . "' WHERE img_name='" .
		  wfStrencode( $name ) . "'";
		wfQuery( $sql, DB_WRITE, $fname );
		
		$sql = "UPDATE cur SET cur_touched='{$now}' WHERE cur_namespace=" .
		  Namespace::getImage() . " AND cur_title='" .
		  wfStrencode( $name ) . "'";
		wfQuery( $sql, DB_WRITE, $fname );
	}

	$log = new LogPage( wfMsg( "uploadlogpage" ), wfMsg( "uploadlogpagetext" ) );
	$da = wfMsg( "uploadedimage", "[[:" . $wgLang->getNsText(
	  Namespace::getImage() ) . ":{$name}|{$name}]]" );
	$ta = wfMsg( "uploadedimage", $name );
	$log->addEntry( $da, $desc, $ta );
}


/* Some generic result counters, pulled out of SearchEngine */

function wfShowingResults( $offset, $limit )
{
	global $wgLang;
	return wfMsg( "showingresults", $wgLang->formatNum( $limit ), $wgLang->formatNum( $offset+1 ) );
}

function wfShowingResultsNum( $offset, $limit, $num )
{
	global $wgLang;
	return wfMsg( "showingresultsnum", $wgLang->formatNum( $limit ), $wgLang->formatNum( $offset+1 ), $wgLang->formatNum( $num ) );
}

function wfViewPrevNext( $offset, $limit, $link, $query = "", $atend = false )
{
	global $wgUser, $wgLang;
	$fmtLimit = $wgLang->formatNum( $limit );
	$prev = wfMsg( "prevn", $fmtLimit );
	$next = wfMsg( "nextn", $fmtLimit );
	$link = wfUrlencode( $link );

	$sk = $wgUser->getSkin();
	if ( 0 != $offset ) {
		$po = $offset - $limit;
		if ( $po < 0 ) { $po = 0; }
		$q = "limit={$limit}&offset={$po}";
		if ( "" != $query ) { $q .= "&{$query}"; }
		$plink = "<a href=\"" . wfLocalUrlE( $link, $q ) . "\">{$prev}</a>";
	} else { $plink = $prev; }

	$no = $offset + $limit;
	$q = "limit={$limit}&offset={$no}";
	if ( "" != $query ) { $q .= "&{$query}"; }

	if ( $atend ) {
		$nlink = $next;
	} else {
		$nlink = "<a href=\"" . wfLocalUrlE( $link, $q ) . "\">{$next}</a>";
	}
	$nums = wfNumLink( $offset, 20, $link , $query ) . " | " .
	  wfNumLink( $offset, 50, $link, $query ) . " | " .
	  wfNumLink( $offset, 100, $link, $query ) . " | " .
	  wfNumLink( $offset, 250, $link, $query ) . " | " .
	  wfNumLink( $offset, 500, $link, $query );

	return wfMsg( "viewprevnext", $plink, $nlink, $nums );
}

function wfNumLink( $offset, $limit, $link, $query = "" )
{
	global $wgUser, $wgLang;
	if ( "" == $query ) { $q = ""; }
	else { $q = "{$query}&"; }
	$q .= "limit={$limit}&offset={$offset}";

	$fmtLimit = $wgLang->formatNum( $limit );
	$s = "<a href=\"" . wfLocalUrlE( $link, $q ) . "\">{$fmtLimit}</a>";
	return $s;
}

function wfClientAcceptsGzip() {
	global $wgUseGzip;
	if( $wgUseGzip ) {
		# FIXME: we may want to blacklist some broken browsers
		if( preg_match(
			'/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
			$_SERVER["HTTP_ACCEPT_ENCODING"],
			$m ) ) {
			if( ( $m[1] == "q" ) && ( $m[2] == 0 ) ) return false;
			wfDebug( " accepts gzip\n" );
			return true;
		}
	}
	return false;
}

# Yay, more global functions!
function wfCheckLimits( $deflimit = 50, $optionname = "rclimit" ) {
	global $wgUser, $wgRequest;
	
	$limit = $wgRequest->getInt( 'limit', 0 );
	if( $limit < 0 ) $limit = 0;
	if( ( $limit == 0 ) && ( $optionname != "" ) ) {
		$limit = (int)$wgUser->getOption( $optionname );
	}
	if( $limit <= 0 ) $limit = $deflimit;
	if( $limit > 5000 ) $limit = 5000; # We have *some* limits...
	
	$offset = $wgRequest->getInt( 'offset', 0 );
	if( $offset < 0 ) $offset = 0;
	if( $offset > 65000 ) $offset = 65000; # do we need a max? what?
	
	return array( $limit, $offset );
}

# Escapes the given text so that it may be output using addWikiText() 
# without any linking, formatting, etc. making its way through. This 
# is achieved by substituting certain characters with HTML entities.
# As required by the callers, <nowiki> is not used. It currently does
# not filter out characters which have special meaning only at the
# start of a line, such as "*".
function wfEscapeWikiText( $text )
{
	$text = str_replace( 
		array( '[',     '|',      "'",     'ISBN '    , '://'     , "\n=" ),
		array( '&#91;', '&#124;', '&#39;', 'ISBN&#32;', '&#58;//' , "\n&#61;" ),
		htmlspecialchars($text) );
	return $text;
}

function wfQuotedPrintable( $string, $charset = "" ) 
{
	# Probably incomplete; see RFC 2045
	if( empty( $charset ) ) {
		global $wgInputEncoding;
		$charset = $wgInputEncoding;
	}
	$charset = strtoupper( $charset );
	$charset = str_replace( "ISO-8859", "ISO8859", $charset ); // ?

	$illegal = '\x00-\x08\x0b\x0c\x0e-\x1f\x7f-\xff=';
	$replace = $illegal . '\t ?_';
	if( !preg_match( "/[$illegal]/", $string ) ) return $string;
	$out = "=?$charset?Q?";
	$out .= preg_replace( "/([$replace])/e", 'sprintf("=%02X",ord("$1"))', $string );
	$out .= "?=";
	return $out;
}

function wfTime(){
	$st = explode( " ", microtime() );
	return (float)$st[0] + (float)$st[1];
}

# Changes the first character to an HTML entity
function wfHtmlEscapeFirst( $text ) {
	$ord = ord($text);
	$newText = substr($text, 1);
	return "&#$ord;$newText";
}

# Sets dest to source and returns the original value of dest
function wfSetVar( &$dest, $source )
{
	$temp = $dest;
	$dest = $source;
	return $temp;
}

# Sets dest to a reference to source and returns the original dest
function &wfSetRef( &$dest, &$source )
{
	$temp =& $dest;
	$dest =& $source;
	return $temp;
}

# This function takes two arrays as input, and returns a CGI-style string, e.g.
# "days=7&limit=100". Options in the first array override options in the second.
# Options set to "" will not be output.
function wfArrayToCGI( $array1, $array2 = NULL ) 
{
	if ( !is_null( $array2 ) ) {
		$array1 = $array1 + $array2;
	}

	$cgi = "";
	foreach ( $array1 as $key => $value ) {
		if ( "" !== $value ) {
			if ( "" != $cgi ) {
				$cgi .= "&";
			}
			$cgi .= "{$key}={$value}";
		}
	}
	return $cgi;
}

# This is obsolete, use SquidUpdate::purge()
function wfPurgeSquidServers ($urlArr) {
	SquidUpdate::purge( $urlArr );
}


# wfMerge attempts to merge differences between three texts. 
# Returns true for a clean merge and false for failure or a conflict.

function wfMerge( $old, $mine, $yours, &$result ){
	global $wgDiff3;

	# This check may also protect against code injection in 
	# case of broken installations.
	if(! file_exists( $wgDiff3 ) ){ 
		return false;
	}
	$td = "/tmp/";
	$oldtextFile = fopen( $oldtextName = tempnam( $td, "merge-old-" ), "w" );
	$mytextFile = fopen( $mytextName = tempnam( $td, "merge-mine-" ), "w" );
	$yourtextFile = fopen( $yourtextName = tempnam( $td, "merge-your-" ), "w" );
			
	fwrite( $oldtextFile, $old ); fclose( $oldtextFile ); 
	fwrite( $mytextFile, $mine ); fclose( $mytextFile ); 
	fwrite( $yourtextFile, $yours ); fclose( $yourtextFile );
	$cmd = "{$wgDiff3} -a --overlap-only $mytextName $oldtextName $yourtextName";
	$handle = popen( $cmd, "r" );

	if( fgets( $handle ) ){
		$conflict = true;
	} else {
		$conflict = false;
	}
	pclose( $handle );
	$cmd = "{$wgDiff3} -a -e --merge $mytextName $oldtextName $yourtextName";
	$handle = popen( $cmd, "r" );
	$result = "";
	do {
		$data = fread( $handle, 8192 );
		if ( strlen( $data ) == 0 ) {
			break;
		}
		$result .= $data;
	} while ( true );
	pclose( $handle );
	unlink( $mytextName ); unlink( $oldtextName ); unlink( $yourtextName );
	return ! $conflict;
}

function wfVarDump( $var )
{
	global $wgOut;
	$s = str_replace("\n","<br>\n", var_export( $var, true ) . "\n");
	if ( headers_sent() || !@is_object( $wgOut ) ) {
		print $s;
	} else {
		$wgOut->addHTML( $s );
	}
}

?>