<?php
/*
* ==== comments to be removed when patch is accepted :
* this patch also assumes small patches in :
* - Defines.php
* - DefaultSettings.php
** $wgSpecialExportDownload = MW_EXPORT_DISPO_SUGGESTED ;
** $wgSpecialExportFilename = MW_EXPORT_FILENAME_DEFAULT ;
** $wgSpecialExportPrefix = MW_EXPORT_DEFAULT_PREFIX ;
* - Language.php (+ LanguageFr.php, De, etc)
** exportpromptdisposition
** exportpromptfilename
** exportsubmit
*/

# Copyright (C) 2003 Brion Vibber <brion@pobox.com>
# http://www.mediawiki.org/
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
# http://www.gnu.org/copyleft/gpl.html
/**
 *
 * @package MediaWiki
 * @subpackage SpecialPage
 */

# This is not a valid entry point, perform no further processing unless MEDIAWIKI is defined
if( !defined( 'MEDIAWIKI' ) ) {
	die( "This file is part of MediaWiki and is not a valid entry point\n" );
}

/** */
require_once( 'Revision.php' );

/*
* ==== comment to be removed after patch acceptance ====
* why not just boolean's for the related parameters ?
* do we expect other values ?
*/
define( 'MW_EXPORT_FULL',     0 );
define( 'MW_EXPORT_CURRENT',  1 );

define( 'MW_EXPORT_BUFFER',   0 );
define( 'MW_EXPORT_STREAM',   1 );

/*
* ==== comment to be removed after patch acceptance ===
* wfSpecialExport does 4 things :
* 1 - process the request and/or the config parameters
* 2 - send HTTP header(s)
* 3 - send the XML output
* 4 - build the form
* Because this patch increases a little bit tasks 1, 2 and 4,
* it seems more convenient to leave task 1 here,
* but to move tasks 2, 3 and 4 in separate functions.
* In order to avoid wfXxx name space pollution, these 3 functions
* are created as static function of class WikiExporter
* doHeaders() , doExport() , doForm
*/

/**
 * Entry point
 * @param $page string
 */
function wfSpecialExport( $page = '' ) {
	global $wgRequest;

	// config parameters  :

	$wgSpecialExportFilename = is_integer($wgSpecialExportFilename) ?
	$wgSpecialExportFilename : MW_EXPORT_FILENAME_DEFAULT ;
	$wgSpecialExportDownload = is_integer($wgSpecialExportDownload) ?
	$wgSpecialExportDownload : MW_EXPORT_DISPO_DEFAULT ;
	$wgSpecialExportPrefix = is_string($wgSpecialExportPrefix) ?
	$wgSpecialExportPrefix : MW_EXPORT_DEFAULT_PREFIX ;

	// proceed/prepare request :
	
	if( $wgRequest->getVal( 'action' ) == 'submit') {
		$page = $wgRequest->getText( 'pages' );
		$curonly = $wgRequest->getCheck( 'curonly' );
		$szRequesXmlFileName = $wgRequest->getText( 'szXmlFileName' );
		$zRequestDispo = $wgRequest->getCheck( 'zDispo' );
	} else {
		# Pre-check the 'current version only' box in the UI
		$curonly = true;
	}

	if( $page != '' ) {
		
		// output HTTP header(s) :
		
		WikiExporter::doHeaders(
		// $zXmlDisposition = true // shall we use Content-Disposition ?
		(( $wgSpecialExportDownload == MW_EXPORT_DISPO_ALLWAYS) || $zRequestDispo )
		// , $szSuggestedPrefix = MW_EXPORT_DEFAULT_PREFIX
		, $wgSpecialExportPrefix
		// , $zDate = true
		, (($wgSpecialExportFilename == MW_EXPORT_FILENAME_ASK_ELSE_TIMESTAMP)
		|| ($wgSpecialExportFilename == MW_EXPORT_FILENAME_TIMESTAMP))
		, $szXmlFileName 
		// , $zRelyOnFileName = false
		// , $uMaxLength = 250 // RARELY USED !
		// , $zGerman = true  // RARELY USED !
		) ;
		
		// output XML :
		
		WikiExporter::doExport(
		$page
		// , $history = MW_EXPORT_CURRENT
		, ( $curonly ? MW_EXPORT_CURRENT : MW_EXPORT_FULL )
		// , $buffer = MW_EXPORT_BUFFER
		) ;
		
	} else {
		
		// prepare the form :
		
		WikiExporter::doForm(
		// $zCurOnly = true // preset value of the 'current v. all' checkbox
		$curonly
		// , $zDisposition = true // preset value for the 'download' checkbox
		, (($wgSpecialExportDownload == MW_EXPORT_DISPO_SUGGESTED) || $zRequestDispo)
		// , $szXmlDispositionFileName = '' // preset value for the file name
		, $szXmlFileName
		// , $zAskFilename = true // shall we prompt the user for a filename?
		, (($wgSpecialExportFilename == MW_EXPORT_FILENAME_ASK_ELSE_TIMESTAMP)
		|| ($wgSpecialExportFilename == MW_EXPORT_FILENAME_ASK_ELSE_RANDOM))
		// , $zAskDisposition = true // shall we prompt the user for download?
		, (($wgSpecialExportDownload == MW_EXPORT_DISPO_PERHAPS)
		|| ($wgSpecialExportDownload == MW_EXPORT_DISPO_SUGGESTED))
		// , $szSuggestedPrefix = MW_EXPORT_DEFAULT_PREFIX
		, $wgSpecialExportPrefix
		// , $zDate = true
		, (($wgSpecialExportFilename == MW_EXPORT_FILENAME_ASK_ELSE_TIMESTAMP)
		|| ($wgSpecialExportFilename == MW_EXPORT_FILENAME_TIMESTAMP))
		// , $zRelyOnFileName = false
		// , $uMaxLength = 250 // RARELY USED !
		// , $zGerman = true  // RARELY USED !
		) ;
	}
}

/**
 * @package MediaWiki
 * @subpackage SpecialPage
 */
class WikiExporter {
	/**#@+
	* @access public
	* @static
	*/

	/**
	 * @param boolean $zXmlDisposition : shall we use Content-Disposition ?
     * @param string $szSuggestedPrefix
     * @param boolean $zDate : use a timestamp (otherwise use a random value)
	 * @param string $szXmlDispositionFileName 
	 * @param boolean $zRelyOnFileName (turn on if you are sure file name is ok, probably beacause it was generated automatically)	 
     * @param unsigned $uMaxLength (RARE) Maximum filename length. Default is 250 characters.
     * @param boolean $zGerman (RARE) proceed also german characters
	 */
	function doHeaders(
	$zXmlDisposition = true // shall we use Content-Disposition ?
	, $szSuggestedPrefix = MW_EXPORT_DEFAULT_PREFIX
	, $zDate = true
	, $szXmlDispositionFileName = ''
	, $zRelyOnFileName = false
	, $uMaxLength = 250 // RARELY USED !
	, $zGerman = true  // RARELY USED !
	)
	{
		global $wgOut ;
		$wgOut->disable();
		header( "Content-type: application/xml; charset=utf-8" );
		if($zXmlDisposition)
		{
			if( ! $zRelyOnFileName )
			{
				$szXmlDispositionFileName = wfUnixFileName(
				$szXmlDispositionFileName,$uMaxLength,$zGerman) ;
			}
			if(! $szXmlDispositionFileName)
			{
				$szXmlDispositionFileName = wfSuggestFileName(
				$szSuggestedPrefix,$zDate,$uMaxLength) ;
			}
			header("Content-Disposition: attachment; filename=\"{$szXmlDispositionFileName}\"'");
		}
	}

	/**
	 * factorize and run...
	 *
	 * @param string $page
	 * @param unsigned $history one of MW_EXPORT_FULL or MW_EXPORT_CURRENT
	 * @param unsigned $buffer one of MW_EXPORT_BUFFER or MW_EXPORT_STREAM
	 */
	function doExport(
	$page
	/*
	* ==== comment to be removed after patch acceptance ====
	* why not just boolean's for these 2 parameters ?
	*/
	, $history = MW_EXPORT_CURRENT
	, $buffer = MW_EXPORT_BUFFER
	)
	{
		$pages = explode( "\n", $page );
		$db =& wfGetDB( DB_SLAVE );
		$exporter = new WikiExporter(
		$db
		, $history = MW_EXPORT_CURRENT
		, $buffer = MW_EXPORT_BUFFER
		);
		/*
		* ==== comment to be removed after patch acceptance ====
		* Mind that openStream() and closeStream() are, in fact, static functions
		*/
		$exporter->openStream();
		// WikiExporter::openStream(); //...
		$exporter->pagesByName( $pages );
		$exporter->closeStream();
		// WikiExporter::closeStream(); //...
	}

	/**
	 * write down the Export form on $wgOut
	 *
	 * @param boolean $curonly ($zCurOnly) preset value of the 'current v. all' checkbox 
	 * @param boolean $zDisposition preset value for the 'download' checkbox
	 * @param string $szXmlDispositionFileName preset value for the file name
	 * @param boolean $zAskFilename shall we prompt the user for a filename?	 
	 * @param boolean $zAskDisposition shall we prompt the user for download?	 
	 * @param boolean $zDate use time stamp if we need to generate a file name
	 * @param boolean $zRelyOnFileName (turn on if you are sure file name is ok, probably beacause it was generated automatically)	 
	 * @param unsigned $uMaxLength (rarely used)
	 * @param boolean $zGerman (rarely used)
	 */
	function doForm(
	$zCurOnly = true // preset value of the 'current v. all' checkbox
	, $zDisposition = true // preset value for the 'download' checkbox
	, $szXmlDispositionFileName = '' // preset value for the file name
	, $zAskFilename = true // shall we prompt the user for a filename?
	, $zAskDisposition = true // shall we prompt the user for download?
	, $szSuggestedPrefix = MW_EXPORT_DEFAULT_PREFIX
	, $zDate = true
	, $zRelyOnFileName = false
	, $uMaxLength = 250 // RARELY USED !
	, $zGerman = true  // RARELY USED !
	)
	{
		global $wgOut ;

		$wgOut->addWikiText( wfMsg( "exporttext" ) );
		$titleObj = Title::makeTitle( NS_SPECIAL, "Export" );
		$action = $titleObj->escapeLocalURL( 'action=submit' );
		/*
		* === comment to be removed after patch acceptance :
		* there was a minor bug here : $curonly was ignored
		*/
		$szCurOnlyChecked = $zCurOnly ? " checked='checked' " : '' ;
		$szPromptCurOnly = wfMsg( "exportcuronly" ) ;
		$wgOut->addHTML( "
<form method='post' action=\"$action\">
<input type='hidden' name='action' value='submit' />
<textarea name='pages' cols='40' rows='10'></textarea><br />
<label><input type='checkbox' name='curonly' value='true' {$szCurOnlyChecked} />
{$szPromptCurOnly}</label><br />
" ) ;

		if($zAskDisposition)
		{
			/*
			* === comment to be removed after patch acceptance :
			* === Mind that 'exportpromptdisposition' is a NEW message.
			*/
			$szPromptDisposition = wfMsg('exportpromptdisposition') ;
			$szDispositionChecked = $zDisposition ? " checked='checked' " : '' ;
			$wgOut->addHTML( "
<label><input type='checkbox' name='zDispo' value='true' {$szDispositionChecked} />
{$szPromptDisposition}</label><br />
" );		
		}

		if($zAskFilename)
		{
			/*
			* === comment to be removed after patch acceptance :
			* === Mind that 'exportpromptfilename' is a NEW message.
			*/
			$szPromptFilename = wfMsg('exportpromptfilename') ;
			if( ! $zRelyOnFileName )
			{
				/*
				$szXmlDispositionFileName may perfectly be empty.
				However, if it is provided, then it MUST be ok!
				It is probably already builded automatically and correct.
				Anyway, we still make an ultimate checking.
				*/
				$szXmlDispositionFileName = trim($szXmlDispositionFileName) ;
				if($szXmlDispositionFileName)
				{
					$szXmlDispositionFileName = wfUnixFileName($szXmlDispositionFileName,$uMaxLength,$zGerman) ;
				}
			}
			if(! $szXmlDispositionFileName)
			{
				$szXmlDispositionFileName = wfSuggestFileName($szSuggestedPrefix,$zDate,$uMaxLength) ;
			}
			$wgOut->addHTML( "
<label>{$szPromptFilename}</label>
<input type='text' name='szXmlFileName' value='{$szXmlDispositionFileName}' size='40' />
<br />
" );
		}

		/*
		* === comment to be removed after patch acceptance :
		* === Mind that 'exportsubmit' is a NEW message.
		* The reason is that, at least in french, standard words often used on submit buttons
		* such as 'submit', 'send', 'apply', 'transmit' are very ambiguous.
		* 'Send' is generally translated by 'Envoyer'.
		* But what means 'envoyer'? From where/who? To where/who?
		* Why not 'receive' or 'recevoir' ? etc
		* An *explicit* word such as 'Export', 'Import', 'Download', 'Upload'
		* must absolutely be used (at least in some languages)...
		*/
		$szSubmit = wfMsg('exportsubmit') ;
		$wgOut->addHTML( "
<input type='submit' value='{$szSubmit}' />
</form>
" );
		/*
		* ==== comments to be removed when patch is accepted :
		* Mind the 3 new messages (see Language.php)
		* - exportpromptdisposition
		* - exportpromptfilename
		* - exportsubmit
		*/
	}

	/**#@-*/

	/**#@+
	* @access private
	*/
	/**
	* @var function
	*/
	var $pageCallback = null;
	/**
	* @var function
	*/
	var $revCallback = null;
	/**
	* @var unsigned mode 
	*/
	var $history ;
	/**
	* @var unsigned mode
	*/
	var $buffer ;
	/**
	* @var Database
	*/
	var $db ;
	/**#@-*/

	/**
	 * If using MW_EXPORT_STREAM to stream a large amount of data,
	 * provide a database connection which is not managed by
	 * LoadBalancer to read from: some history blob types will
	 * make additional queries to pull source data while the
	 * main query is still running.
	 *
	 * @param Database $db
	 * @param unsigned $history one of MW_EXPORT_FULL or MW_EXPORT_CURRENT
	 * @param unsigned $buffer one of MW_EXPORT_BUFFER or MW_EXPORT_STREAM
	 */
	function WikiExporter(
	&$db
	, $history = MW_EXPORT_CURRENT
	, $buffer = MW_EXPORT_BUFFER
	) {
		$this->db =& $db;
		$this->history = $history;
		$this->buffer  = $buffer;
	}

	/**
	 * Set a callback to be called after each page in the output
	 * stream is closed. The callback will be passed a database row
	 * object with the last revision output.
	 *
	 * A set callback can be removed by passing null here.
	 *
	 * @param mixed $callback
	 */
	function setPageCallback( $callback ) {
		$this->pageCallback = $callback;
	}

	/**
	 * Set a callback to be called after each revision in the output
	 * stream is closed. The callback will be passed a database row
	 * object with the revision data.
	 *
	 * A set callback can be removed by passing null here.
	 *
	 * @param mixed $callback
	 */
	function setRevisionCallback( $callback ) {
		$this->revCallback = $callback;
	}

	/**
	 * Returns the export schema version.
	 * @return string
	 */
	function schemaVersion() {
		return "0.3";
	}

	/**
	 * Opens the XML output stream's root <mediawiki> element.
	 * This does not include an xml directive, so is safe to include
	 * as a subelement in a larger XML stream. Namespace and XML Schema
	 * references are included.
	 *
	 * To capture the stream to a string, use PHP's output buffering
	 * functions. Output will be encoded in UTF-8.
	 */
	function openStream() {
		global $wgContLanguageCode;
		$ver = $this->schemaVersion();
		print wfElement( 'mediawiki', array(
		'xmlns'              => "http://www.mediawiki.org/xml/export-$ver/",
		'xmlns:xsi'          => "http://www.w3.org/2001/XMLSchema-instance",
		'xsi:schemaLocation' => "http://www.mediawiki.org/xml/export-$ver/ " .
		"http://www.mediawiki.org/xml/export-$ver.xsd",
		'version'            => $ver,
		'xml:lang'           => $wgContLanguageCode ),
		null ) . "\n";
		$this->siteInfo();
	}

	function siteInfo() {
		$info = array(
		$this->sitename(),
		$this->homelink(),
		$this->generator(),
		$this->caseSetting(),
		$this->namespaces() );
		print "<siteinfo>\n";
		foreach( $info as $item ) {
			print "  $item\n";
		}
		print "</siteinfo>\n";
	}

	function sitename() {
		global $wgSitename;
		return wfElement( 'sitename', array(), $wgSitename );
	}

	function generator() {
		global $wgVersion;
		return wfElement( 'generator', array(), "MediaWiki $wgVersion" );
	}

	function homelink() {
		$page = Title::newFromText( wfMsgForContent( 'mainpage' ) );
		return wfElement( 'base', array(), $page->getFullUrl() );
	}

	function caseSetting() {
		global $wgCapitalLinks;
		// "case-insensitive" option is reserved for future
		$sensitivity = $wgCapitalLinks ? 'first-letter' : 'case-sensitive';
		return wfElement( 'case', array(), $sensitivity );
	}

	function namespaces() {
		global $wgContLang;
		$spaces = "<namespaces>\n";
		foreach( $wgContLang->getNamespaces() as $ns => $title ) {
			$spaces .= '    ' . wfElement( 'namespace',
			array( 'key' => $ns ),
			str_replace( '_', ' ', $title ) ) . "\n";
		}
		$spaces .= "  </namespaces>";
		return $spaces;
	}

	/**
	 * Closes the output stream with the closing root element.
	 * Call when finished dumping things.
	 */
	function closeStream() {
		print "</mediawiki>\n";
	}

	/**
	 * Dumps a series of page and revision records for all pages
	 * in the database, either including complete history or only
	 * the most recent version.
	 *
	 *
	 * @param Database $db
	 */
	function allPages() {
		return $this->dumpFrom( '' );
	}

	/**
	 * @param Title $title
	 */
	function pageByTitle( $title ) {
		return $this->dumpFrom(
		'page_namespace=' . $title->getNamespace() .
		' AND page_title=' . $this->db->addQuotes( $title->getDbKey() ) );
	}

	function pageByName( $name ) {
		$title = Title::newFromText( $name );
		if( is_null( $title ) ) {
			return WikiError( "Can't export invalid title" );
		} else {
			return $this->pageByTitle( $title );
		}
	}

	function pagesByName( $names ) {
		foreach( $names as $name ) {
			$this->pageByName( $name );
		}
	}


	// -------------------- private implementation below --------------------

	/**#@+
	* @access private
	*/

	function dumpFrom( $cond = '' ) {
		$fname = 'WikiExporter::dumpFrom';
		wfProfileIn( $fname );

		$page     = $this->db->tableName( 'page' );
		$revision = $this->db->tableName( 'revision' );
		$text     = $this->db->tableName( 'text' );

		if( $this->history == MW_EXPORT_FULL ) {
			$join = 'page_id=rev_page';
		} elseif( $this->history == MW_EXPORT_CURRENT ) {
			$join = 'page_id=rev_page AND page_latest=rev_id';
		} else {
			wfProfileOut( $fname );
			return new WikiError( "$fname given invalid history dump type." );
		}
		$where = ( $cond == '' ) ? '' : "$cond AND";

		if( $this->buffer == MW_EXPORT_STREAM ) {
			$prev = $this->db->bufferResults( false );
		}
		if( $cond == '' ) {
			// Optimization hack for full-database dump
			$pageindex = 'FORCE INDEX (PRIMARY)';
			$revindex = 'FORCE INDEX(page_timestamp)';
		} else {
			$pageindex = '';
			$revindex = '';
		}
		$result = $this->db->query(
		"SELECT * FROM
				$page $pageindex,
				$revision $revindex,
				$text
				WHERE $where $join AND rev_text_id=old_id
				ORDER BY page_id", $fname );
		$wrapper = $this->db->resultObject( $result );
		$this->outputStream( $wrapper );

		if( $this->buffer == MW_EXPORT_STREAM ) {
			$this->db->bufferResults( $prev );
		}

		wfProfileOut( $fname );
	}

	/**
	 * Runs through a query result set dumping page and revision records.
	 * The result set should be sorted/grouped by page to avoid duplicate
	 * page records in the output.
	 *
	 * The result set will be freed once complete. Should be safe for
	 * streaming (non-buffered) queries, as long as it was made on a
	 * separate database connection not managed by LoadBalancer; some
	 * blob storage types will make queries to pull source data.
	 *
	 * @param ResultWrapper $resultset
	 */
	function outputStream( $resultset ) {
		$last = null;
		while( $row = $resultset->fetchObject() ) {
			if( is_null( $last ) ||
			$last->page_namespace != $row->page_namespace ||
			$last->page_title     != $row->page_title ) {
				if( isset( $last ) ) {
					$this->closePage( $last );
				}
				$this->openPage( $row );
				$last = $row;
			}
			$this->dumpRev( $row );
		}
		if( isset( $last ) ) {
			$this->closePage( $last );
		}
		$resultset->free();
	}

	/**
	 * Opens a <page> section on the output stream, with data
	 * from the given database row.
	 *
	 * @param object $row
	 */
	function openPage( $row ) {
		print "<page>\n";
		$title = Title::makeTitle( $row->page_namespace, $row->page_title );
		print '  ' . wfElementClean( 'title', array(), $title->getPrefixedText() ) . "\n";
		print '  ' . wfElement( 'id', array(), $row->page_id ) . "\n";
		if( '' != $row->page_restrictions ) {
			print '  ' . wfElement( 'restrictions', array(),
			$row->page_restrictions ) . "\n";
		}
	}

	/**
	 * Closes a <page> section on the output stream.
	 * If a per-page callback has been set, it will be called
	 * and passed the last database row used for this page.
	 *
	 * @param object $row
	 */
	function closePage( $row ) {
		print "</page>\n";
		if( isset( $this->pageCallback ) ) {
			call_user_func( $this->pageCallback, $row );
		}
	}

	/**
	 * Dumps a <revision> section on the output stream, with
	 * data filled in from the given database row.
	 *
	 * @param object $row
	 */
	function dumpRev( $row ) {
		$fname = 'WikiExporter::dumpRev';
		wfProfileIn( $fname );

		print "    <revision>\n";
		print "      " . wfElement( 'id', null, $row->rev_id ) . "\n";

		$ts = wfTimestamp2ISO8601( $row->rev_timestamp );
		print "      " . wfElement( 'timestamp', null, $ts ) . "\n";

		print "      <contributor>";
		if( $row->rev_user ) {
			print wfElementClean( 'username', null, $row->rev_user_text );
			print wfElement( 'id', null, $row->rev_user );
		} else {
			print wfElementClean( 'ip', null, $row->rev_user_text );
		}
		print "</contributor>\n";

		if( $row->rev_minor_edit ) {
			print  "      <minor/>\n";
		}
		if( $row->rev_comment != '' ) {
			print "      " . wfElementClean( 'comment', null, $row->rev_comment ) . "\n";
		}

		$text = Revision::getRevisionText( $row );
		print "      " . wfElementClean( 'text',
		array( 'xml:space' => 'preserve' ), $text ) . "\n";

		print "    </revision>\n";

		wfProfileOut( $fname );

		if( isset( $this->revCallback ) ) {
			call_user_func( $this->revCallback, $row );
		}
	}

	/**#@-*/
}

/**
* @param string $ts
* @return string 
*/
function wfTimestamp2ISO8601( $ts ) {
	#2003-08-05T18:30:02Z
	return preg_replace( '/^(....)(..)(..)(..)(..)(..)$/', '$1-$2-$3T$4:$5:$6Z', $ts );
}

/*
* ==== comment to be removed after patch acceptance ====
* The next 3 global functions are, in my personal implementation,
* located, for reusability, in includes/GlobalFunctions.php rather than here
* because they can be usefull eveywhere there is a need to build a filename.
* Mind that we voluntary divide into 3 functions as to improve reability.
* I suggest to move these 3 functions into GlobalFunctions.php
*/

/**
* Generates a unique file name e.g. for a downloaded file
*
* @param string $szSuggestedPrefix
* @param boolean $zDate : use a timestamp (otherwise use a random value)
* @param unsigned $uMaxLength Maximum filename length. Default is 250 characters.
* @return string generated file name 
*/
function wfSuggestFileName(
$szPrefix = MW_EXPORT_DEFAULT_PREFIX
, $zDate = true
, $uMaxLength = 250
)
{
	$szName =  $szPrefix . '-' . ( $zDate ? date("Y-m-d-H-i-s") : mt_rand(1234567,9876543) ) ;
	// still verify : illegal prefix ? length ?
	return wfUnixFileName($szName,$uMaxLength) ;
}

/**
* Generates an usefull Unix filename besides the original one.
*
* @param string $szName The filename to be processed.
* @param unsigned $uMaxLength Maximum filename length. Default is 250 characters.
* @param boolean $zGerman proceed also german characters
* @return string
*/
function wfUnixFileName(
$szName
, $uMaxLength = 250
, $zGerman= true
)
{
	$uMaxLength = max(1,min(250,$uMaxLength)) ;
	// remove accents :
	$szName = wfRemoveAccents($szName,$zGerman) ;
	// Replace any remaining special characters with an underscore.
	$szName = preg_replace('/[^a-z0-9.-]+/i', '_', $szName);
	// Remove any useless underscores, e.g. _a_a_._a_ becomes a_a.a
	$szName = preg_replace('/_*\b_*/', '', $szName);
	// Crop the filename if it's too long.
	while (strlen($szName) > $uMaxLength)
	$szName = preg_replace('/.\b/', '', $szName, 1);
	return $szName;
}

/**
* wfRemoveAccents replaces some special 'european' characters
* so that a name may be used e.g. to build a file name.
*
* Mind that the returned string has the same length of the original
* if $zGerman==false, but may have a different length otherwise.
*
* @param string $szName a name with accents
* @param boolean $zGerman proceed also german characters
* @return string the name with accents removed (replacing)
*/
function wfRemoveAccents($szName, $zGerman=true)
{
	if($zGerman)
	{
		// Replace German umlauts and other special characters.
		$szName = str_replace("ß", "ss", $szName);
		$szName = preg_replace('/[ÄÖÜäöü]/', '\0e', $szName);
	}
	// Proceed accents, etc
	$szName = strtr($szName,
	"ÀÁÂÃÄÅÆÈÉÊËÌÍÎÏÒÓÔÕÖØÙÚÛÜàáâãäåæèéêëìíîïòóôõöøùúûüçÇß",
	"AAAAAAAEEEEIIIIOOOOOOUUUUaaaaaaaeeeeiiiioooooouuuucCs");
	/*
	* Mind that the process of "ß", "ü", etc is different if 'german' is on or off!
	*/
	return $szName ;
}

/**
* Function 'xmlsafe' UNUSED, renamed to wfXmlSafe to stick to mw conventions
*
* @param string $string
* @return string $string
* @todo move function into WikiExporter class or decide to rename as wfXmlSafe
* @todo this function is currently unused...
*/
function wfXmlSafe( $string ) {
	$fname = 'xmlsafe';
	wfProfileIn( $fname );

	/**
	 * The page may contain old data which has not been properly normalized.
	 * Invalid UTF-8 sequences or forbidden control characters will make our
	 * XML output invalid, so be sure to strip them out.
	 */
	$string = UtfNormal::cleanUp( $string );

	$string = htmlspecialchars( $string );
	wfProfileOut( $fname );
	return $string;
}

/**
* ==== comment to be removed after patch acceptance ====
* I systematically destroy whitespaces after the final ? >
* These caracters are generally harmless.
* However, in some applications (cookies, headers) they are dangerous.
* So, it's a matter of principle : just delete them eveywhere
*/
?>