CakePHP cache with dynamic groups

PowerCache.php

<?php

App::uses('Cache', 'Cache');

class PowerCache {

    public static function write($key, $value, $config = 'default', $groups = []) {
        if (!empty($groups)) {
            $groups = !is_array($groups) ? [$groups] : $groups;
            $groupsConfig = !empty(Configure::read('powercache.config'))
                ? Configure::read('powercache.config')
                : 'default';
            $groupsPrefix = !empty(Configure::read('powercache.prefix'))
                ? Configure::read('powercache.prefix')
                : 'pc_';

            foreach ($groups as $group) {
                $groupKeys = Cache::read($groupsPrefix . $group, $groupsConfig);
                $groupKey = $key . '|' . $config;

                if (!$groupKeys) {
                    $groupKeys = [];
                }

                if (!in_array($groupKey, $groupKeys)) {
                    $groupKeys[] = $groupKey;

                    Cache::write($groupsPrefix . $group, $groupKeys, $groupsConfig);
                }
            }
        }

        return Cache::write($key, $value, $config);
    }

    public static function clearGroup($groups = [], $config = 'default') {
        $groups = !is_array($groups) ? [$groups] : $groups;
        $groupsConfig = !empty(Configure::read('powercache.config'))
            ? Configure::read('powercache.config')
            : 'default';
        $groupsPrefix = !empty(Configure::read('powercache.prefix'))
            ? Configure::read('powercache.prefix')
            : 'pc_';

        foreach ($groups as $group) {
            $keys = Cache::read($groupsPrefix . $group, $groupsConfig);

            if (!empty($keys)) {
                foreach ($keys as $key) {
                    list($key, $config) = explode('|', $key);
                    Cache::delete($key, $config);
                }
            }
        }
    }

    public static function read($key, $config = 'default') {
        return Cache::read($key, $config);
    }
}