<?php

/**
 * This extension displays recent changes only of articles that match certain criteria
 * The way this extension works in to OVERRIDE the default recent changes function
 *
 * Read the code or see the URL below for the documentation for use
 * Uses SpecialPreferencesExtension to allow users to specify default filtering criteria
 *
 * Author: Austin Che <http://openwetware.org/wiki/User:Austin>
 */

$wgExtensionFunctions[] = "wfExtensionSpecialRecentchangesfilter";
$wgExtensionCredits['specialpage'][] = array(
    'name' => 'Special:Recentchangesfilter',
    'version' => '2006/03/11',
    'author' => 'Austin Che',
    'url' => 'http://openwetware.org/wiki/User:Austin/Extensions/Recentchangesfilter',
    'description' => 'Enables filtering the items that show up in the recent changes list',
);

function wfExtensionSpecialRecentchangesfilter() 
{
    global $wgMessageCache;
    $wgMessageCache->addMessages(array('rcfilters' => 'Filters:', 
                                       'rcfiltertitle' => 'Recent changes filtering', 
                                       'rcfilter' => 'Filter list',
                                       'rcfilterdefault' => 'Default filter number',
                                       'tog-rcfilterenable' => 'Enable user-specific filtered recent changes',
                                       'defaultrcfilter' => '[None];[Watchlist]w=1',
                                       ));

    // use the preferences extension only if it has been loaded
    if (function_exists("wfAddPreferences"))
    {
        wfAddPreferences(array(array('section' => "prefs-rc", 
                                     'html' => "<fieldset><legend>" . wfMsg('rcfiltertitle') . "</legend>"),
                               array('name' => "rcfilterenable", 
                                     'section' => "prefs-rc", 
                                     'type' => PREF_TOGGLE_T),
                               array('name' => "rcfilter",
                                     'section' => "prefs-rc",
                                     'type' => PREF_TEXT_T,
                                     'default' => wfMsg('defaultrcfilter'),
                                     'size' => 50),
                               array('name' => "rcfilterdefault",
                                     'section' => "prefs-rc",                     
                                     'type' => PREF_INT_T,
                                     'size' => 5,
                                     'default' => 0),
                               array('section' => "prefs-rc", 
                                     'html' => "</fieldset>"),
                               ));
    }

    // we 'override' the default recent changes special page with our own
    // first remove the default
    SpecialPage::removePage("Recentchanges");

    // We recreate a new special page called Recentchanges
    // this will automatically call require_once( 'SpecialRecentchanges.php' );
    // which is what we need as we use functions there
    // however, we want to redefine the entry point to our own filter function
    SpecialPage::addPage( new IncludableSpecialPage( 'Recentchanges', '', true, 
                                                     'wfSpecialRecentchangesfilter'));
}

/**
 * Entrypoint
 * @param string $par path info, the filter criteria if set
 */
function wfSpecialRecentchangesfilter($par, $specialPage)
{
    // decide whether to filter or not
    // in default case, we call the normal recent changes
    global $wgRequest, $wgUser;
    if ($par || $wgRequest->getVal('filter') || $wgUser->getOption('rcfilterenable'))
        return filterRecentchanges($par, $specialPage);
    else
        return wfSpecialRecentchanges($par, $specialPage);
}

/**
 * Our filtering version of recent changes 
 * Much of this function was copied from the default SpecialRecentchanges.php
 */
function filterRecentchanges( $par, $specialPage ) 
{
	global $wgUser, $wgOut, $wgLang, $wgContLang, $wgTitle, $wgMemc, $wgDBname;
	global $wgRequest, $wgSitename, $wgLanguageCode, $wgContLanguageCode;
	global $wgFeedClasses, $wgUseRCPatrol;
	global $wgRCShowWatchingUsers, $wgShowUpdatedMarker;
	global $wgLinkCache;
	$fname = 'wfSpecialRecentchanges';

    // Get query parameters
	$feedFormat = $wgRequest->getVal( 'feed' );

	$defaults = array(
                      /* int  */ 'days' => $wgUser->getDefaultOption('rcdays'),
                      /* int  */ 'limit' => $wgUser->getDefaultOption('rclimit'),
                      /* bool */ 'hideminor' => false,
                      /* bool */ 'hidebots' => true,
                      /* bool */ 'hideliu' => false,
                      /* bool */ 'hidepatrolled' => false,
                      /* text */ 'from' => '',
                      /* text */ 'namespace' => null,
                      /* bool */ 'invert' => false,
                      );

	extract($defaults);
	

	$days = $wgUser->getOption( 'rcdays' );
	if ( !$days ) { $days = $defaults['days']; }
	$days = $wgRequest->getInt( 'days', $days );

	$limit = $wgUser->getOption( 'rclimit' );
	if ( !$limit ) { $limit = $defaults['limit']; }

	$limit = $wgRequest->getInt( 'limit', $limit );

	/* order of selection: url > preferences > default */
	$hideminor = $wgRequest->getBool( 'hideminor', $wgUser->getOption( 'hideminor') ? true : $defaults['hideminor'] );
	
    $filter = $wgRequest->getVal( 'filter' );

    // As a feed, use limited settings only
	if ( $feedFormat ) 
    {
		global $wgFeedLimit;
		if( $limit > $wgFeedLimit ) {
			$options['limit'] = $wgFeedLimit;
		}
	} 
    else 
    {
		$namespace = $wgRequest->getIntOrNull( 'namespace' );
		$invert = $wgRequest->getBool( 'invert', $defaults['invert'] );
		$hidebots = $wgRequest->getBool( 'hidebots', $defaults['hidebots'] );
		$hideliu = $wgRequest->getBool( 'hideliu', $defaults['hideliu'] );
		$hidepatrolled = $wgRequest->getBool( 'hidepatrolled', $defaults['hidepatrolled'] );
		$from = $wgRequest->getVal( 'from', $defaults['from'] );	

        // Get query parameters from path
        // This is treated differently from the default Recentchanges so isn't completely compatible
        // Only things allowed other than filter criteria are limit/days separated by & (instead of ,)
        // everything else is treated as part of the filter criteria
        if ( $par ) 
        {
            $bits = preg_split( '/\s*&\s*/', trim( $par ) );
            foreach ( $bits as $bit ) 
            {
                if (preg_match('/^limit=(\d+)$/', $bit, $m)) 
                    $limit = $m[1];
                else if (preg_match('/^days=(\d+)$/', $bit, $m)) 
                    $days = $m[1];
                else 
                    $filter .= $bit;
            }
        }
	}

	if ( $limit < 0 || $limit > 5000 ) $limit = $defaults['limit'];

    if ($wgUser->getOption('rcfilterenable'))
        $filters = getUserFilters($wgUser->getOption('rcfilter'));
    if (! $filter && $filters)
        $filter = $filters[$wgUser->getOption('rcfilterdefault')][1];

    $filtersql = filterCondition($filter);

    // Database connection and caching
	$dbr =& wfGetDB( DB_SLAVE );
	extract( $dbr->tableNames( 'recentchanges', 'watchlist' ) );

	
	$cutoff_unixtime = time() - ( $days * 86400 );
	$cutoff_unixtime = $cutoff_unixtime - ($cutoff_unixtime % 86400);
	$cutoff = $dbr->timestamp( $cutoff_unixtime );
	if(preg_match('/^[0-9]{14}$/', $from) and $from > wfTimestamp(TS_MW,$cutoff)) {
		$cutoff = $dbr->timestamp($from);
	} else {
		$from = $defaults['from'];
	}
		
    // 10 seconds server-side caching max
	$wgOut->setSquidMaxage( 10 );

    // Get last modified date, for client caching
    // Don't use this if we are using the patrol feature, patrol changes don't update the timestamp
	$lastmod = $dbr->selectField( 'recentchanges', 'MAX(rc_timestamp)', false, $fname );
	if ( $feedFormat || !$wgUseRCPatrol ) {
		if( $lastmod && $wgOut->checkLastModified( $lastmod ) ){
            // Client cache fresh and headers sent, nothing more to do.
			return;
		}
	}

	$hidem  = $hideminor ? 'AND rc_minor=0' : '';
	$hidem .= $hidebots ? ' AND rc_bot=0' : '';
	$hidem .= $hideliu ? ' AND rc_user=0' : '';
	$hidem .= $hidepatrolled ? ' AND rc_patrolled=0' : '';
	$hidem .= is_null( $namespace ) ?  '' : ' AND rc_namespace' . ($invert ? '!=' : '=') . $namespace;

	// This is the big thing!

	$uid = $wgUser->getID();
    $notifts = ($wgShowUpdatedMarker?",wl_notificationtimestamp":"");

	// Perform query
	$sql2 = "SELECT $recentchanges.*" . ($uid ? ",wl_user".$notifts : "") . " FROM $recentchanges " .
        ($uid ? "LEFT OUTER JOIN $watchlist ON wl_user={$uid} AND wl_title=rc_title AND wl_namespace=rc_namespace " : "") .
        "WHERE rc_timestamp > '{$cutoff}' {$hidem} {$filtersql}" .
        "ORDER BY rc_timestamp DESC LIMIT {$limit}";
	$res = $dbr->query( $sql2, $fname );

	// Fetch results, prepare a batch link existence check query
	$rows = array();
	$batch = new LinkBatch;
	while( $row = $dbr->fetchObject( $res ) ){
		$rows[] = $row;
		// User page link
		$title = Title::makeTitleSafe( NS_USER, $row->rc_user_text );
		$batch->addObj( $title );

		// User talk
		$title = Title::makeTitleSafe( NS_USER_TALK, $row->rc_user_text );
		$batch->addObj( $title );

	}
	$dbr->freeResult( $res );

	// Run existence checks
	$batch->execute( $wgLinkCache );

	if( $feedFormat ) {
		rcOutputFeed( $rows, $feedFormat, $limit, $hideminor, $lastmod );
	} else {

        // Web output...

		// Output header
		if ( !$specialPage->including() ) {
			$wgOut->addWikiText( wfMsgForContent( "recentchangestext" ) );
		
			// Dump everything here
			$nondefaults = array();
		
			wfAppendToArrayIfNotDefault( 'days', $days, $defaults, $nondefaults);
			wfAppendToArrayIfNotDefault( 'limit', $limit , $defaults, $nondefaults);
			wfAppendToArrayIfNotDefault( 'hideminor', $hideminor, $defaults, $nondefaults);
			wfAppendToArrayIfNotDefault( 'hidebots', $hidebots, $defaults, $nondefaults);
			wfAppendToArrayIfNotDefault( 'hideliu', $hideliu, $defaults, $nondefaults);
			wfAppendToArrayIfNotDefault( 'hidepatrolled', $hidepatrolled, $defaults, $nondefaults);
			wfAppendToArrayIfNotDefault( 'from', $from, $defaults, $nondefaults);
			wfAppendToArrayIfNotDefault( 'namespace', $namespace, $defaults, $nondefaults);
			wfAppendToArrayIfNotDefault( 'invert', $invert, $defaults, $nondefaults);

            if ($filter) $nondefaults["filter"] = $filter;

			// Add end of the texts
			$wgOut->addHTML( '<div class="rcoptions">' . rcOptionsPanel( $defaults, $nondefaults ) );
			$wgOut->addHTML( rcNamespaceForm( $namespace, $invert, $nondefaults));
            $wgOut->addHTML(rcFilterOptions($filters, $nondefaults, $filter));
            $wgOut->addHTML('</div>');
		}

		// And now for the content
		$sk = $wgUser->getSkin();
		$wgOut->setSyndicated( true );
		$list =& new ChangesList( $sk );
		$s = $list->beginRecentChangesList();
		$counter = 1;
		foreach( $rows as $obj ){
			if( $limit == 0) {
				break;
			}

			if ( ! ( $hideminor     && $obj->rc_minor     ) &&
			     ! ( $hidepatrolled && $obj->rc_patrolled ) ) {
				$rc = RecentChange::newFromRow( $obj );
				$rc->counter = $counter++;

				if ($wgShowUpdatedMarker
					&& !empty( $obj->wl_notificationtimestamp )
					&& ($obj->rc_timestamp >= $obj->wl_notificationtimestamp)) {
                    $rc->notificationtimestamp = true;
				} else {
					$rc->notificationtimestamp = false;
				}

				if ($wgRCShowWatchingUsers && $wgUser->getOption( 'shownumberswatching' )) {
					$sql3 = "SELECT COUNT(*) AS n FROM $watchlist WHERE wl_title='" . $dbr->strencode($obj->rc_title) ."' AND wl_namespace=$obj->rc_namespace" ;
					$res3 = $dbr->query( $sql3, 'wfSpecialRecentChanges');
					$x = $dbr->fetchObject( $res3 );
					$rc->numberofWatchingusers = $x->n;
				} else {
					$rc->numberofWatchingusers = 0;
				}
				$s .= $list->recentChangesLine( $rc, !empty( $obj->wl_user ) );
				--$limit;
			}
		}
		$s .= $list->endRecentChangesList();
		$wgOut->addHTML( $s );
	}

    // debug
    //$wgOut->addHTML("<p>filter = $filter<p>");
    //$wgOut->addHTML("<p>sql = $filtersql <p>");
}

function rcFilterOptions($filters, $nondefaults, $currentfilter)
{
    $str = "";
    if (! $filters)
        return "";
    foreach ($filters as $filter)
    {
        if ($str) $str .= " | ";
        // if a filter is empty (i.e. no filter) it doesn't get included in the cgi
        // string by makeOptionsLink which calls wfArrayToCGI
        // we need it to be present however (to distinguish it from no specified filter)
        // so we set it to a space which is equivalent to no filter
        if ($filter[1] == '')
            $filter[1] = ' ';
        $link = makeOptionsLink( $filter[0], array( 'filter' => $filter[1] ), $nondefaults);
        if ($currentfilter == $filter[1])
            $link = "<b>$link</b>";
        $str .= $link;
    }
    return wfMsg('rcfilters') . "  " . $str;
}

function getUserFilters($filterstr)
{
    // given a string representing the list of filters, parses and returns an array of filters
    // each element is 2 elements (name, filter)
    $filterlist = explode(';', trim($filterstr));
    $filters = array();
    $num = 0;
    global $wgOut;
    foreach ($filterlist as $filter)
    {
        if (preg_match('/^\[(.*)\](.*)$/', $filter, $m))
        {
            $name = $m[1];
            $filter = $m[2];
        }
        else
            $name = $num;
        $filters[] = array($name, $filter);
        $num++;
    }
    return $filters;
}

function filterCondition($filter)
{
    global $wgUser, $wgContLang;
	$uid = $wgUser->getID();
    $filtersql = "";
    if ($filter)
    {
        $disjuncts = preg_split( '/\s*,\s*/', trim( $filter ) );
        foreach ( $disjuncts as $disjunct ) 
        {
            $disjunctsql = "";
            $literals = preg_split( '/\s*\^\s*/', trim( $disjunct ) );
            foreach ( $literals as $literal ) 
            {
                $litsql = "";
                if (! preg_match( '/^(.*)=(.*)$/', $literal, $m ) ) 
                {
                    // default is match type 'b'
                    $m[1] = 'b';
                    $m[2] = $literal;
                }
                // all our matching conditions don't need spaces (which aren't valid in titles)
                // also some browsers convert spaces to +
                // convert both to underscores
                $m[2] = str_replace('+', ' ', $m[2]);
                $m[2] = str_replace(' ', '_', $m[2]);

                switch ($m[1])
                {
                    case "b":
                        $litsql = "rc_title LIKE '$m[2]%'";
                        break;
                    case "nb":
                        $litsql = "rc_title NOT LIKE '$m[2]%'";
                        break;
                    case "e":
                        $litsql = "rc_title LIKE '%$m[2]'";
                        break;
                    case "ne":
                        $litsql = "rc_title NOT LIKE '%$m[2]'";
                        break;
                    case "c":
                        $litsql = "rc_title LIKE '%$m[2]%'";
                        break;
                    case "nc":
                        $litsql = "rc_title NOT LIKE '%$m[2]%'";
                        break;
                    case "m":
                        $litsql = "rc_title LIKE '$m[2]'";
                        break;
                    case "nm":
                        $litsql = "rc_title NOT LIKE '$m[2]'";
                        break;
                    case "n":
                        $n = is_numeric($m[2]) ? $m[2] : $wgContLang->getNsIndex($m[2]);
                        if (is_numeric($n))
                            $litsql = "rc_namespace=$n";
                        break;
                    case "nn":
                        $n = is_numeric($m[2]) ? $m[2] : $wgContLang->getNsIndex($m[2]);
                        if (is_numeric($n))
                            $litsql = "rc_namespace<>$n";
                        break;
                    case "u":
                        $id = User::idFromName($m[2]);
                        // if $id = 0, no such name, in which case we match non-logged in users
                        $litsql = "rc_user=$id";
                        break;
                    case "nu":
                        $id = User::idFromName($m[2]);
                        $litsql = "rc_user<>$id";
                        break;
                    case "w":
                        if ($uid)
                            $litsql = "wl_user IS NOT NULL";
                        break;
                    case "nw":
                        if ($uid)
                            $litsql = "wl_user IS NULL";
                        break;
                }

                if ($litsql)
                    $disjunctsql = $disjunctsql ? "$disjunctsql AND ($litsql)" : "($litsql)";
            }
            if ($disjunctsql)
                $filtersql = $filtersql ? "$filtersql OR ( $disjunctsql) " : "($disjunctsql)";
		}
        if ($filtersql)
            $filtersql = "AND ( $filtersql )";
    }
    return $filtersql;
}

?>