Magic call method for setting and removing object references with Redis

timetable.db.php

/**
 * Basic call method for setting and removing object properties
 *
 * @param String    $method
 * @param Array     $args
 *
 * @return Mixed
 *
 * @access public
 */
public function __call($method, $args)
{
    $return = false;
    $reference = isset($args[0]) ? $args[0] : null;
    if($this->id && strlen($reference) > 0) {                       // If object is loaded
        if(preg_match('~^(add|remove)([A-Z])(.*)$~', $method, $matches)) {
            $class = strtolower($matches[2]) . $matches[3];
            if(!class_exists($class)) {                                 // Check if class exists
                $key = $this->_singular . ':' . $this->id . ':' . self::_pluralize($class);
            }
            else {
                $instance = new $class();
                $key = $this->_singular . ':' . $this->id . ':' . $instance->_plural;
            }
            $type = self::$_redis->type($key);
            if(isset($args[1]) && is_int($args[1])) {                   // If secound param is int
                $score = $args[1];                                          // Setup value for the score in sorted set
            }
            if(is_string($reference)) {                                 // If reference is string
                $md5    = md5($reference);                                  // Calculate MD5 hash from string
                $md5Key = $this->_singular.':'.$this->id.':'.$md5;          // Build the md5 key
            }
            if(isset($score) && !isset($md5)) {                         // If want to be stored as sorted set (zset)
                if(($type == 0 || $type == 4) && $matches[1] == 'add') {    // If key does not exists or is of type zset
                    $return = self::$_redis->zAdd($key, $score, $reference);
                }
                else {
                    throw new Exception('Key \'' . $key . '\' must be of type zset.');
                }
            }
            else {                                                      // Store as values in non-sorted (regular) set or removal of member in sorted set
                switch($matches[1]) {
                    case 'add':
                        if(isset($md5) && !self::$_redis->exists($md5Key)) {    // If md5Key is set md5Key not exists
                            self::$_redis->set($md5Key, $this->id);                 // Add reference to object
                            $return = self::$_redis->sAdd($key, $reference);        // Add reference to objects list
                        }
                        elseif(!isset($md5)) {                                  // Else if md5 is not set
                            $return = self::$_redis->sAdd($key, $reference);        // Just add the reference to objects list
                        }
                        break;
                    case 'remove':
                        if($type == 4) { // If key is of type zset
                            $return = self::$_redis->zRemove($key, $reference);
                        }
                        else {          // Else it's a regular set
                            if(isset($md5Key)) {
                                self::$_redis->delete($md5Key);
                            }
                            $return = self::$_redis->sRemove($key, $reference);
                        }
                        break;
                }
            }
        }
        else {
            throw new Exception('Undefined method \'' . $method . '\'');
        }
    }
    return $return;
}