public static function getLastStorageSync($userID)
{
$lastModified = false;
$libraryIDs = Zotero_Libraries::getUserLibraries($userID);
$shardIDs = Zotero_Shards::getUserShards($userID);
foreach ($shardIDs as $shardID) {
$sql = "SELECT UNIX_TIMESTAMP(serverDateModified) AS time FROM items\n\t\t\t\t\tJOIN storageFileItems USING (itemID)\n\t\t\t\t\tWHERE libraryID IN (" . implode(', ', array_fill(0, sizeOf($libraryIDs), '?')) . ")\n\t\t\t\t\tORDER BY time DESC LIMIT 1";
$time = Zotero_DB::valueQuery($sql, $libraryIDs, $shardID);
if ($time > $lastModified) {
$lastModified = $time;
}
}
return $lastModified;
}