class CacheableNormalization

class CacheableNormalization implements CacheableDependencyInterface {
    use CacheableDependencyTrait;
    
    /**
     * A normalized value.
     *
     * @var mixed
     */
    protected $normalization;
    
    /**
     * CacheableNormalization constructor.
     *
     * @param \Drupal\Core\Cache\CacheableDependencyInterface $cacheability
     *   The cacheability metadata for the normalized data.
     * @param array|string|int|float|bool|null $normalization
     *   The normalized data. This value must not contain any
     *   CacheableNormalizations.
     */
    public function __construct(CacheableDependencyInterface $cacheability, $normalization) {
        assert(is_array($normalization) && static::hasNoNestedInstances($normalization) || is_string($normalization) || is_int($normalization) || is_float($normalization) || is_bool($normalization) || is_null($normalization));
        $this->normalization = $normalization;
        $this->setCacheability($cacheability);
    }
    
    /**
     * Creates a CacheableNormalization instance without any special cacheability.
     *
     * @param array|string|int|float|bool|null $normalization
     *   The normalized data. This value must not contain any
     *   CacheableNormalizations.
     *
     * @return static
     *   The CacheableNormalization.
     */
    public static function permanent($normalization) {
        return new static(new CacheableMetadata(), $normalization);
    }
    
    /**
     * Gets the decorated normalization.
     *
     * @return array|string|int|float|bool|null
     *   The normalization.
     */
    public function getNormalization() {
        return $this->normalization;
    }
    
    /**
     * Converts the object to a CacheableOmission if the normalization is empty.
     *
     * @return self|\Drupal\jsonapi\Normalizer\Value\CacheableOmission
     *   A CacheableOmission if the normalization is considered empty, self
     *   otherwise.
     */
    public function omitIfEmpty() {
        return empty($this->normalization) ? new CacheableOmission($this) : $this;
    }
    
    /**
     * Gets a new CacheableNormalization with an additional dependency.
     *
     * @param \Drupal\Core\Cache\CacheableDependencyInterface $dependency
     *   The new cacheable dependency.
     *
     * @return static
     *   A new object based on the current value with an additional cacheable
     *   dependency.
     */
    public function withCacheableDependency(CacheableDependencyInterface $dependency) {
        return new static(CacheableMetadata::createFromObject($this)->addCacheableDependency($dependency), $this->normalization);
    }
    
    /**
     * Collects an array of CacheableNormalizations into a single instance.
     *
     * @param \Drupal\jsonapi\Normalizer\Value\CacheableNormalization[] $cacheable_normalizations
     *   An array of CacheableNormalizations.
     *
     * @return static
     *   A new CacheableNormalization. Each input value's cacheability will be
     *   merged into the return value's cacheability. The return value's
     *   normalization will be an array of the input's normalizations. This method
     *   does *not* behave like array_merge() or NestedArray::mergeDeep().
     */
    public static function aggregate(array $cacheable_normalizations) {
        assert(Inspector::assertAllObjects($cacheable_normalizations, CacheableNormalization::class));
        return new static(array_reduce($cacheable_normalizations, function (CacheableMetadata $merged, CacheableNormalization $item) {
            return $merged->addCacheableDependency($item);
        }, new CacheableMetadata()), array_reduce(array_keys($cacheable_normalizations), function ($merged, $key) use ($cacheable_normalizations) {
            if (!$cacheable_normalizations[$key] instanceof CacheableOmission) {
                $merged[$key] = $cacheable_normalizations[$key]->getNormalization();
            }
            return $merged;
        }, []));
    }
    
    /**
     * Ensures that no nested values are instances of this class.
     *
     * @param array|\Traversable $array
     *   The traversable object which may contain instance of this object.
     *
     * @return bool
     *   Whether the given object or its children have CacheableNormalizations in
     *   them.
     */
    protected static function hasNoNestedInstances($array) {
        foreach ($array as $value) {
            if ((is_array($value) || $value instanceof \Traversable) && !static::hasNoNestedInstances($value) || $value instanceof static) {
                return FALSE;
            }
        }
        return TRUE;
    }

}