class StorageReplaceDataWrapper

class StorageReplaceDataWrapper implements StorageInterface {
    use DependencySerializationTrait;
    
    /**
     * The configuration storage to be wrapped.
     *
     * @var \Drupal\Core\Config\StorageInterface
     */
    protected $storage;
    
    /**
     * The configuration replacement data, keyed by configuration object name.
     *
     * @var array
     */
    protected $replacementData = [];
    
    /**
     * The storage collection.
     *
     * @var string
     */
    protected $collection;
    
    /**
     * Constructs a new StorageReplaceDataWrapper.
     *
     * @param \Drupal\Core\Config\StorageInterface $storage
     *   A configuration storage to be used to read and write configuration.
     * @param string $collection
     *   (optional) The collection to store configuration in. Defaults to the
     *   default collection.
     */
    public function __construct(StorageInterface $storage, $collection = StorageInterface::DEFAULT_COLLECTION) {
        $this->storage = $storage;
        $this->collection = $collection;
        $this->replacementData[$collection] = [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function exists($name) {
        return isset($this->replacementData[$this->collection][$name]) || $this->storage
            ->exists($name);
    }
    
    /**
     * {@inheritdoc}
     */
    public function read($name) {
        if (isset($this->replacementData[$this->collection][$name])) {
            return $this->replacementData[$this->collection][$name];
        }
        return $this->storage
            ->read($name);
    }
    
    /**
     * {@inheritdoc}
     */
    public function readMultiple(array $names) {
        $data = $this->storage
            ->readMultiple($names);
        foreach ($names as $name) {
            if (isset($this->replacementData[$this->collection][$name])) {
                $data[$name] = $this->replacementData[$this->collection][$name];
            }
        }
        return $data;
    }
    
    /**
     * {@inheritdoc}
     */
    public function write($name, array $data) {
        if (isset($this->replacementData[$this->collection][$name])) {
            unset($this->replacementData[$this->collection][$name]);
        }
        return $this->storage
            ->write($name, $data);
    }
    
    /**
     * {@inheritdoc}
     */
    public function delete($name) {
        if (isset($this->replacementData[$this->collection][$name])) {
            unset($this->replacementData[$this->collection][$name]);
        }
        return $this->storage
            ->delete($name);
    }
    
    /**
     * {@inheritdoc}
     */
    public function rename($name, $new_name) {
        if (isset($this->replacementData[$this->collection][$name])) {
            $this->replacementData[$this->collection][$new_name] = $this->replacementData[$this->collection][$name];
            unset($this->replacementData[$this->collection][$name]);
        }
        return $this->storage
            ->rename($name, $new_name);
    }
    
    /**
     * {@inheritdoc}
     */
    public function encode($data) {
        return $this->storage
            ->encode($data);
    }
    
    /**
     * {@inheritdoc}
     */
    public function decode($raw) {
        return $this->storage
            ->decode($raw);
    }
    
    /**
     * {@inheritdoc}
     */
    public function listAll($prefix = '') {
        $names = $this->storage
            ->listAll($prefix);
        $additional_names = [];
        if ($prefix === '') {
            $additional_names = array_keys($this->replacementData[$this->collection]);
        }
        else {
            foreach (array_keys($this->replacementData[$this->collection]) as $name) {
                if (strpos($name, $prefix) === 0) {
                    $additional_names[] = $name;
                }
            }
        }
        if (!empty($additional_names)) {
            $names = array_unique(array_merge($names, $additional_names));
        }
        return $names;
    }
    
    /**
     * {@inheritdoc}
     */
    public function deleteAll($prefix = '') {
        if ($prefix === '') {
            $this->replacementData[$this->collection] = [];
        }
        else {
            foreach (array_keys($this->replacementData[$this->collection]) as $name) {
                if (strpos($name, $prefix) === 0) {
                    unset($this->replacementData[$this->collection][$name]);
                }
            }
        }
        return $this->storage
            ->deleteAll($prefix);
    }
    
    /**
     * {@inheritdoc}
     */
    public function createCollection($collection) {
        return new static($this->storage
            ->createCollection($collection), $collection);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getAllCollectionNames() {
        return $this->storage
            ->getAllCollectionNames();
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCollectionName() {
        return $this->collection;
    }
    
    /**
     * Replaces the configuration object data with the supplied data.
     *
     * @param $name
     *   The configuration object name whose data to replace.
     * @param array $data
     *   The configuration data.
     *
     * @return $this
     */
    public function replaceData($name, array $data) {
        $this->replacementData[$this->collection][$name] = $data;
        return $this;
    }

}