Starting index update (updates)...\n");

if ($mods = get_records_select('modules')) {
    $mods = array_merge($mods, search_get_additional_modules());
    
    foreach ($mods as $mod) {
        $class_file = $CFG->dirroot.'/search/documents/'.$mod->name.'_document.php';
        $get_document_function = $mod->name.'_single_document';
        $delete_function = $mod->name.'_delete';
        $db_names_function = $mod->name.'_db_names';
        $updates = array();
        
        if (file_exists($class_file)) {
            require_once($class_file);
            
            //if both required functions exist
            if (function_exists($delete_function) and function_exists($db_names_function) and function_exists($get_document_function)) {
                mtrace("Checking $mod->name module for updates.");
                $valuesArray = $db_names_function();
                if ($valuesArray){
                    foreach($valuesArray as $values){
                    
                        $where = (isset($values[5])) ? 'AND ('.$values[5].')' : '';
                        $itemtypes = ($values[4] != '*') ? " AND itemtype = '{$values[4]}' " : '' ;

                        //TODO: check 'in' syntax with other RDBMS' (add and update.php as well)
                        $table = SEARCH_DATABASE_TABLE;
                        $query = "
                            SELECT 
                                docid,
                                itemtype
                            FROM 
                                {$CFG->prefix}{$table}
                            WHERE
                                doctype = '{$mod->name}'
                                $itemtypes
                        ";
                        $docIds = get_records_sql_menu($query);
                        $docIdList = ($docIds) ? implode("','", array_keys($docIds)) : '' ;
                        
                        $query = "
                            SELECT 
                                id, 
                                {$values[0]} as docid
                            FROM 
                                {$CFG->prefix}{$values[1]} 
                            WHERE 
                                {$values[3]} > {$indexdate} AND 
                                id IN ('{$docIdList}')
                                $where
                        ";
                        $records = get_records_sql($query);
                        if (is_array($records)) {
                            foreach($records as $record) {
                                $updates[] = $delete_function($record->docid, $docIds[$record->docid]);
                            } 
                        } 
                    }
                    
                    foreach ($updates as $update) {
                        ++$update_count;
                        
                        //delete old document
                        $doc = $index->find("+docid:{$update->id} +doctype:{$mod->name} +itemtype:{$update->itemtype}");
                        
                        //get the record, should only be one
                        foreach ($doc as $thisdoc) {
                            mtrace("  Delete: $thisdoc->title (database id = $thisdoc->dbid, index id = $thisdoc->id, moodle instance id = $thisdoc->docid)");
                            $dbcontrol->delDocument($thisdoc);
                            $index->delete($thisdoc->id);
                        } 
                        
                        //add new modified document back into index
                        $add = $get_document_function($update->id, $update->itemtype);
                        
                        //object to insert into db
                        $dbid = $dbcontrol->addDocument($add);
                        
                        //synchronise db with index
                        $add->addField(Zend_Search_Lucene_Field::Keyword('dbid', $dbid));
                        mtrace("  Add: $add->title (database id = $add->dbid, moodle instance id = $add->docid)");
                        $index->addDocument($add);
                    } 
                }
                else{
                    mtrace("No types to update.\n");
                }
                mtrace("Finished $mod->name.\n");
            } 
        } 
    } 
} 

//commit changes
$index->commit();

//update index date
set_config("search_indexer_update_date", $startupdatedate);

mtrace("Finished $update_count updates.