<?php
/**
* Global Search Engine for Moodle
* Michael Champanis (mchampan) [cynnical@gmail.com]
* review 1.8+ : Valery Fremaux [valery.fremaux@club-internet.fr] 
* 2007/08/02
*
* Asynchronous index cleaner
*
* Major chages in this review is passing the xxxx_db_names return to
* multiple arity to handle multiple document types modules
*/

require_once('../config.php');
require_once("$CFG->dirroot/search/lib.php");

require_login();

if (empty($CFG->enableglobalsearch)) {
    error(get_string('globalsearchdisabled', 'search'));
}

if (!isadmin()) {
    error(get_string('beadmin', 'search'), "$CFG->wwwroot/login/index.php");
} //if

//check for php5 (lib.php)
if (!search_check_php5()) {
    $phpversion = phpversion();
    mtrace("Sorry, global search requires PHP 5.0.0 or later (currently using version $phpversion)");
    exit(0);
}

require_once("$CFG->dirroot/search/indexlib.php");

$index = new Zend_Search_Lucene(SEARCH_INDEX_PATH);
$dbcontrol = new IndexDBControl();
$deletion_count = 0;
$startcleantime = time();

mtrace('<pre>Starting clean-up of removed records...');
mtrace('Index size before: '.$CFG->search_index_size."\n");

if ($mods = get_records_select('modules')) {
    $mods = array_merge($mods, search_get_additional_modules());
    
    foreach ($mods as $mod) {
        //build function names
        $class_file = $CFG->dirroot.'/search/documents/'.$mod->name.'_document.php';
        $delete_function = $mod->name.'_delete';
        $db_names_function = $mod->name.'_db_names';
        $deletions = 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)) {
                mtrace("Checking $mod->name module for deletions.");
                $valuesArray = $db_names_function();
                if ($valuesArray){
                    foreach($valuesArray as $values){
                       $where = (isset($values[5])) ? 'WHERE '.$values[5] : '';
                       $itemtypes = ($values[4] != '*') ? " itemtype = '{$values[4]}' AND " : '' ;
                       $query = "
                            SELECT 
                                id,
                                {$values[0]}
                            FROM 
                                {$CFG->prefix}{$values[1]}
                                $where
                        ";
                        $docIds = get_records_sql($query);
                        $docIdList = ($docIds) ? implode("','", array_keys($docIds)) : '' ;
                        
                        $table = SEARCH_DATABASE_TABLE;
                        $query = "
                            SELECT 
                                id, 
                                docid 
                            FROM 
                                {$CFG->prefix}{$table}
                            WHERE 
                                doctype = '{$mod->name}' AND 
                                $itemtypes
                                docid not in ('{$docIdList}')
                        ";
                        $records = get_records_sql($query);
                        
                        // build an array of all the deleted records
                        if (is_array($records)) {
                            foreach($records as $record) {
                                $deletions[] = $delete_function($record->docid, $values[4]);
                            }
                        }
                    }
                    
                    foreach ($deletions as $delete) {
                        // find the specific document in the index, using it's docid and doctype as keys
                        $doc = $index->find("+docid:{$delete->id} +doctype:$mod->name +itemtype:{$delete->itemtype}");
                        
                        // get the record, should only be one
                        foreach ($doc as $thisdoc) {
                            ++$deletion_count;
                            mtrace("  Delete: $thisdoc->title (database id = $thisdoc->dbid, index id = $thisdoc->id, moodle instance id = $thisdoc->docid)");
                            
                            //remove it from index and database table
                            $dbcontrol->delDocument($thisdoc);
                            $index->delete($thisdoc->id);
                        }
                    }
                }
                else{
                    mtrace("No types to delete.\n");
                }
                mtrace("Finished $mod->name.\n");
            }
        }
    }
}

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

//update index date and index size
set_config("search_indexer_cleanup_date", $startcleantime);
set_config("search_index_size", (int)$CFG->search_index_size - (int)$deletion_count);

mtrace("Finished $deletion_count removals.");
mtrace('Index size after: '.$index->count().'</pre>');

?>