class BaseFieldDefinition

class BaseFieldDefinition extends ListDataDefinition implements FieldDefinitionInterface, FieldStorageDefinitionInterface, RequiredFieldStorageDefinitionInterface {
    use UnchangingCacheableDependencyTrait;
    use FieldInputValueNormalizerTrait;
    
    /**
     * The field type.
     *
     * @var string
     */
    protected $type;
    
    /**
     * An array of field property definitions.
     *
     * @var \Drupal\Core\TypedData\DataDefinitionInterface[]
     *
     * @see \Drupal\Core\TypedData\ComplexDataDefinitionInterface::getPropertyDefinitions()
     */
    protected $propertyDefinitions;
    
    /**
     * The field schema.
     *
     * @var array
     */
    protected $schema;
    
    /**
     * @var array
     */
    protected $indexes = [];
    
    /**
     * Creates a new field definition.
     *
     * @param string $type
     *   The type of the field.
     *
     * @return static
     *   A new field definition object.
     */
    public static function create($type) {
        $field_definition = new static([]);
        $field_definition->type = $type;
        $field_definition->itemDefinition = FieldItemDataDefinition::create($field_definition);
        // Create a definition for the items, and initialize it with the default
        // settings for the field type.
        $field_type_manager = \Drupal::service('plugin.manager.field.field_type');
        $default_settings = $field_type_manager->getDefaultStorageSettings($type) + $field_type_manager->getDefaultFieldSettings($type);
        $field_definition->itemDefinition
            ->setSettings($default_settings);
        return $field_definition;
    }
    
    /**
     * Creates a new field definition based upon a field storage definition.
     *
     * In cases where one needs a field storage definitions to act like full
     * field definitions, this creates a new field definition based upon the
     * (limited) information available. That way it is possible to use the field
     * definition in places where a full field definition is required; e.g., with
     * widgets or formatters.
     *
     * @param \Drupal\Core\Field\FieldStorageDefinitionInterface $definition
     *   The field storage definition to base the new field definition upon.
     *
     * @return $this
     */
    public static function createFromFieldStorageDefinition(FieldStorageDefinitionInterface $definition) {
        return static::create($definition->getType())
            ->setCardinality($definition->getCardinality())
            ->setConstraints($definition->getConstraints())
            ->setCustomStorage($definition->hasCustomStorage())
            ->setDescription($definition->getDescription())
            ->setLabel($definition->getLabel())
            ->setName($definition->getName())
            ->setProvider($definition->getProvider())
            ->setRevisionable($definition->isRevisionable())
            ->setSettings($definition->getSettings())
            ->setTargetEntityTypeId($definition->getTargetEntityTypeId())
            ->setTranslatable($definition->isTranslatable());
    }
    
    /**
     * {@inheritdoc}
     */
    public static function createFromItemType($item_type) {
        // The data type of a field item is in the form of "field_item:$field_type".
        $parts = explode(':', $item_type, 2);
        return static::create($parts[1]);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getName() {
        return $this->definition['field_name'];
    }
    
    /**
     * Sets the field name.
     *
     * @param string $name
     *   The field name to set.
     *
     * @return static
     *   The object itself for chaining.
     */
    public function setName($name) {
        $this->definition['field_name'] = $name;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getType() {
        return $this->type;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSettings() {
        return $this->getItemDefinition()
            ->getSettings();
    }
    
    /**
     * {@inheritdoc}
     *
     * Note that the method does not unset existing settings not specified in the
     * incoming $settings array.
     *
     * For example:
     * @code
     *   // Given these are the default settings.
     *   $field_definition->getSettings() === [
     *     'fruit' => 'apple',
     *     'season' => 'summer',
     *   ];
     *   // Change only the 'fruit' setting.
     *   $field_definition->setSettings(['fruit' => 'banana']);
     *   // The 'season' setting persists unchanged.
     *   $field_definition->getSettings() === [
     *     'fruit' => 'banana',
     *     'season' => 'summer',
     *   ];
     * @endcode
     *
     * For clarity, it is preferred to use setSetting() if not all available
     * settings are supplied.
     */
    public function setSettings(array $settings) {
        // Assign settings individually, in order to keep the current values
        // of settings not specified in $settings.
        foreach ($settings as $setting_name => $setting) {
            $this->getItemDefinition()
                ->setSetting($setting_name, $setting);
        }
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSetting($setting_name) {
        return $this->getItemDefinition()
            ->getSetting($setting_name);
    }
    
    /**
     * {@inheritdoc}
     */
    public function setSetting($setting_name, $value) {
        $this->getItemDefinition()
            ->setSetting($setting_name, $value);
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getProvider() {
        return $this->definition['provider'] ?? NULL;
    }
    
    /**
     * Sets the name of the provider of this field.
     *
     * @param string $provider
     *   The provider name to set.
     *
     * @return $this
     */
    public function setProvider($provider) {
        $this->definition['provider'] = $provider;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function isTranslatable() {
        return !empty($this->definition['translatable']);
    }
    
    /**
     * Sets whether the field is translatable.
     *
     * @param bool $translatable
     *   Whether the field is translatable.
     *
     * @return $this
     *   The object itself for chaining.
     */
    public function setTranslatable($translatable) {
        $this->definition['translatable'] = $translatable;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function isRevisionable() {
        // Multi-valued base fields are always considered revisionable, just like
        // configurable fields.
        return !empty($this->definition['revisionable']) || $this->isMultiple();
    }
    
    /**
     * Sets whether the field is revisionable.
     *
     * @param bool $revisionable
     *   Whether the field is revisionable.
     *
     * @return $this
     *   The object itself for chaining.
     */
    public function setRevisionable($revisionable) {
        $this->definition['revisionable'] = $revisionable;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCardinality() {
        // @todo Allow to control this.
        return $this->definition['cardinality'] ?? 1;
    }
    
    /**
     * Sets the maximum number of items allowed for the field.
     *
     * Possible values are positive integers or
     * FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED.
     *
     * Note that if the entity type that this base field is attached to is
     * revisionable and the field has a cardinality higher than 1, the field is
     * considered revisionable by default.
     *
     * @param int $cardinality
     *   The field cardinality.
     *
     * @return $this
     */
    public function setCardinality($cardinality) {
        $this->definition['cardinality'] = $cardinality;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function isMultiple() {
        $cardinality = $this->getCardinality();
        return $cardinality == static::CARDINALITY_UNLIMITED || $cardinality > 1;
    }
    
    /**
     * Sets constraints for a given field item property.
     *
     * Note: this overwrites any existing property constraints. If you need to
     * add to the existing constraints, use
     * \Drupal\Core\Field\BaseFieldDefinition::addPropertyConstraints()
     *
     * @param string $name
     *   The name of the property to set constraints for.
     * @param array $constraints
     *   The constraints to set.
     *
     * @return static
     *   The object itself for chaining.
     */
    public function setPropertyConstraints($name, array $constraints) {
        $item_constraints = $this->getItemDefinition()
            ->getConstraints();
        $item_constraints['ComplexData'][$name] = $constraints;
        $this->getItemDefinition()
            ->setConstraints($item_constraints);
        return $this;
    }
    
    /**
     * Adds constraints for a given field item property.
     *
     * Adds a constraint to a property of a base field item. e.g.
     * @code
     * // Limit the field item's value property to the range 0 through 10.
     * // e.g. $node->size->value.
     * $field->addPropertyConstraints('value', [
     *   'Range' => [
     *     'min' => 0,
     *     'max' => 10,
     *   ]
     * ]);
     * @endcode
     *
     * If you want to add a validation constraint that applies to the
     * \Drupal\Core\Field\FieldItemList, use BaseFieldDefinition::addConstraint()
     * instead.
     *
     * Note: passing a new set of options for an existing property constraint will
     * overwrite with the new options.
     *
     * @param string $name
     *   The name of the property to set constraints for.
     * @param array $constraints
     *   The constraints to set.
     *
     * @return static
     *   The object itself for chaining.
     *
     * @see \Drupal\Core\Field\BaseFieldDefinition::addConstraint()
     */
    public function addPropertyConstraints($name, array $constraints) {
        $item_constraints = $this->getItemDefinition()
            ->getConstraint('ComplexData') ?: [];
        if (isset($item_constraints[$name])) {
            // Add the new property constraints, overwriting as required.
            $item_constraints[$name] = $constraints + $item_constraints[$name];
        }
        else {
            $item_constraints[$name] = $constraints;
        }
        $this->getItemDefinition()
            ->addConstraint('ComplexData', $item_constraints);
        return $this;
    }
    
    /**
     * Sets the display options for the field in forms or rendered entities.
     *
     * This enables generic rendering of the field with widgets / formatters,
     * including automated support for "In place editing", and with optional
     * configurability in the "Manage display" / "Manage form display" UI screens.
     *
     * Unless this method is called, the field remains invisible (or requires
     * ad-hoc rendering logic).
     *
     * @param string $display_context
     *   The display context. Either 'view' or 'form'.
     * @param array $options
     *   An array of display options. Refer to
     *   \Drupal\Core\Field\FieldDefinitionInterface::getDisplayOptions() for
     *   a list of supported keys. The options should include at least a 'weight',
     *   or specify 'region' = 'hidden'. The 'default_widget' /
     *   'default_formatter' for the field type will be used if no 'type' is
     *   specified.
     *
     * @return static
     *   The object itself for chaining.
     */
    public function setDisplayOptions($display_context, array $options) {
        $this->definition['display'][$display_context]['options'] = $options;
        return $this;
    }
    
    /**
     * Sets whether the display for the field can be configured.
     *
     * @param string $display_context
     *   The display context. Either 'view' or 'form'.
     * @param bool $configurable
     *   Whether the display options can be configured (e.g., via the "Manage
     *   display" / "Manage form display" UI screens). If TRUE, the options
     *   specified via getDisplayOptions() act as defaults.
     *
     * @return static
     *   The object itself for chaining.
     */
    public function setDisplayConfigurable($display_context, $configurable) {
        // If no explicit display options have been specified, default to 'hidden'.
        if (empty($this->definition['display'][$display_context])) {
            $this->definition['display'][$display_context]['options'] = [
                'region' => 'hidden',
            ];
        }
        $this->definition['display'][$display_context]['configurable'] = $configurable;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDisplayOptions($display_context) {
        return $this->definition['display'][$display_context]['options'] ?? NULL;
    }
    
    /**
     * {@inheritdoc}
     */
    public function isDisplayConfigurable($display_context) {
        return $this->definition['display'][$display_context]['configurable'] ?? FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDefaultValueLiteral() {
        return $this->definition['default_value'] ?? [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDefaultValueCallback() {
        return $this->definition['default_value_callback'] ?? NULL;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDefaultValue(FieldableEntityInterface $entity) {
        // Allow custom default values function.
        if ($callback = $this->getDefaultValueCallback()) {
            $value = call_user_func($callback, $entity, $this);
        }
        else {
            $value = $this->getDefaultValueLiteral();
        }
        $value = $this->normalizeValue($value, $this->getMainPropertyName());
        // Allow the field type to process default values.
        $field_item_list_class = $this->getClass();
        return $field_item_list_class::processDefaultValue($value, $entity, $this);
    }
    
    /**
     * {@inheritdoc}
     */
    public function setDefaultValue($value) {
        if ($value === NULL) {
            $value = [];
        }
        // Unless the value is an empty array, we may need to transform it.
        if (!is_array($value) || !empty($value)) {
            if (!is_array($value)) {
                $value = [
                    [
                        $this->getMainPropertyName() => $value,
                    ],
                ];
            }
            elseif (is_array($value) && !is_numeric(array_keys($value)[0])) {
                $value = [
                    0 => $value,
                ];
            }
        }
        $this->definition['default_value'] = $value;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function setDefaultValueCallback($callback) {
        if (isset($callback) && !is_string($callback)) {
            throw new \InvalidArgumentException('Default value callback must be a string, like "function_name" or "ClassName::methodName"');
        }
        $this->definition['default_value_callback'] = $callback;
        return $this;
    }
    
    /**
     * Returns the initial value for the field.
     *
     * @return array
     *   The initial value for the field, as a numerically indexed array of items,
     *   each item being a property/value array (array() for no default value).
     */
    public function getInitialValue() {
        return $this->normalizeValue($this->definition['initial_value'], $this->getMainPropertyName());
    }
    
    /**
     * Sets an initial value for the field.
     *
     * @param mixed $value
     *   The initial value for the field. This can be either:
     *   - a literal, in which case it will be assigned to the first property of
     *     the first item;
     *   - a numerically indexed array of items, each item being a property/value
     *     array;
     *   - a non-numerically indexed array, in which case the array is assumed to
     *     be a property/value array and used as the first item;
     *   - an empty array for no initial value.
     *
     * @return $this
     */
    public function setInitialValue($value) {
        // @todo Implement initial value support for multi-value fields in
        //   https://www.drupal.org/node/2883851.
        if ($this->isMultiple()) {
            throw new FieldException('Multi-value fields can not have an initial value.');
        }
        $this->definition['initial_value'] = $this->normalizeValue($value, $this->getMainPropertyName());
        return $this;
    }
    
    /**
     * Returns the name of the field that will be used for getting initial values.
     *
     * @return string|null
     *   The field name.
     */
    public function getInitialValueFromField() {
        return $this->definition['initial_value_from_field'] ?? NULL;
    }
    
    /**
     * Sets a field that will be used for getting initial values.
     *
     * @param string $field_name
     *   The name of the field that will be used for getting initial values.
     * @param mixed $default_value
     *   (optional) The default value for the field, in case the inherited value
     *   is NULL. This can be either:
     *   - a literal, in which case it will be assigned to the first property of
     *     the first item;
     *   - a numerically indexed array of items, each item being a property/value
     *     array;
     *   - a non-numerically indexed array, in which case the array is assumed to
     *     be a property/value array and used as the first item;
     *   - an empty array for no initial value.
     *   If the field being added is required or an entity key, it is recommended
     *   to provide a default value.
     *
     * @return $this
     */
    public function setInitialValueFromField($field_name, $default_value = NULL) {
        $this->definition['initial_value_from_field'] = $field_name;
        $this->setInitialValue($default_value);
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getOptionsProvider($property_name, FieldableEntityInterface $entity) {
        // If the field item class implements the interface, create an orphaned
        // runtime item object, so that it can be used as the options provider
        // without modifying the entity being worked on.
        if (is_subclass_of($this->getItemDefinition()
            ->getClass(), OptionsProviderInterface::class)) {
            $items = $entity->get($this->getName());
            return \Drupal::service('plugin.manager.field.field_type')->createFieldItem($items, 0);
        }
        // @todo Allow setting custom options provider.
        //   https://www.drupal.org/node/2002138
    }
    
    /**
     * {@inheritdoc}
     */
    public function getPropertyDefinition($name) {
        if (!isset($this->propertyDefinitions)) {
            $this->getPropertyDefinitions();
        }
        if (isset($this->propertyDefinitions[$name])) {
            return $this->propertyDefinitions[$name];
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function getPropertyDefinitions() {
        if (!isset($this->propertyDefinitions)) {
            $class = $this->getItemDefinition()
                ->getClass();
            $this->propertyDefinitions = $class::propertyDefinitions($this);
        }
        return $this->propertyDefinitions;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getPropertyNames() {
        return array_keys($this->getPropertyDefinitions());
    }
    
    /**
     * {@inheritdoc}
     */
    public function getMainPropertyName() {
        $class = $this->getItemDefinition()
            ->getClass();
        return $class::mainPropertyName();
    }
    
    /**
     * {@inheritdoc}
     */
    public function __sleep() : array {
        // Do not serialize the statically cached property definitions.
        $vars = get_object_vars($this);
        unset($vars['propertyDefinitions'], $vars['typedDataManager']);
        return array_keys($vars);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getTargetEntityTypeId() {
        return $this->definition['entity_type'] ?? NULL;
    }
    
    /**
     * Sets the ID of the type of the entity this field is attached to.
     *
     * @param string $entity_type_id
     *   The name of the target entity type to set.
     *
     * @return $this
     */
    public function setTargetEntityTypeId($entity_type_id) {
        $this->definition['entity_type'] = $entity_type_id;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getTargetBundle() {
        return $this->definition['bundle'] ?? NULL;
    }
    
    /**
     * Sets the bundle this field is defined for.
     *
     * @param string|null $bundle
     *   The bundle, or NULL if the field is not bundle-specific.
     *
     * @return $this
     */
    public function setTargetBundle($bundle) {
        $this->definition['bundle'] = $bundle;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSchema() {
        if (!isset($this->schema)) {
            // Get the schema from the field item class.
            $definition = \Drupal::service('plugin.manager.field.field_type')->getDefinition($this->getType());
            $class = $definition['class'];
            $schema = $class::schema($this);
            // Fill in default values.
            $schema += [
                'columns' => [],
                'unique keys' => [],
                'indexes' => [],
                'foreign keys' => [],
            ];
            // Merge custom indexes with those specified by the field type. Custom
            // indexes prevail.
            $schema['indexes'] = $this->indexes + $schema['indexes'];
            $this->schema = $schema;
        }
        return $this->schema;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getColumns() {
        $schema = $this->getSchema();
        return $schema['columns'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function hasCustomStorage() {
        return !empty($this->definition['custom_storage']) || $this->isComputed();
    }
    
    /**
     * {@inheritdoc}
     */
    public function isBaseField() {
        return TRUE;
    }
    
    /**
     * Sets the storage behavior for this field.
     *
     * @param bool $custom_storage
     *   Pass FALSE if the storage takes care of storing the field,
     *   TRUE otherwise.
     *
     * @return $this
     *
     * @throws \LogicException
     *   Thrown if custom storage is to be set to FALSE for a computed field.
     */
    public function setCustomStorage($custom_storage) {
        if (!$custom_storage && $this->isComputed()) {
            throw new \LogicException("Entity storage cannot store a computed field.");
        }
        $this->definition['custom_storage'] = $custom_storage;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFieldStorageDefinition() {
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getUniqueStorageIdentifier() {
        return $this->getTargetEntityTypeId() . '-' . $this->getName();
    }
    
    /**
     * {@inheritdoc}
     */
    public function getUniqueIdentifier() {
        // If we have a specified target bundle, we're dealing with a bundle base
        // field definition, so we need to include it in the unique identifier.
        if ($this->getTargetBundle()) {
            return $this->getTargetEntityTypeId() . '-' . $this->getTargetBundle() . '-' . $this->getName();
        }
        return $this->getUniqueStorageIdentifier();
    }
    
    /**
     * {@inheritdoc}
     */
    public function isDeleted() {
        return !empty($this->definition['deleted']);
    }
    
    /**
     * Sets whether the field storage is deleted.
     *
     * @param bool $deleted
     *   Whether the field storage is deleted.
     *
     * @return $this
     */
    public function setDeleted($deleted) {
        $this->definition['deleted'] = $deleted;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getConfig($bundle) {
        $override = BaseFieldOverride::loadByName($this->getTargetEntityTypeId(), $bundle, $this->getName());
        if ($override) {
            return $override;
        }
        return BaseFieldOverride::createFromBaseFieldDefinition($this, $bundle);
    }
    
    /**
     * {@inheritdoc}
     */
    public function isStorageRequired() {
        if (isset($this->definition['storage_required'])) {
            return (bool) $this->definition['storage_required'];
        }
        // Default to the 'required' property of the base field.
        return $this->isRequired();
    }
    
    /**
     * Sets whether the field storage is required.
     *
     * @param bool $required
     *   Whether the field storage is required.
     *
     * @return static
     *   The object itself for chaining.
     */
    public function setStorageRequired($required) {
        $this->definition['storage_required'] = $required;
        return $this;
    }
    
    /**
     * Magic method: Implements a deep clone.
     */
    public function __clone() {
        parent::__clone();
        // The itemDefinition (\Drupal\Core\Field\TypedData\FieldItemDataDefinition)
        // has a property fieldDefinition, which is a recursive reference to the
        // parent BaseFieldDefinition, therefore the reference to the old object has
        // to be overwritten with a reference to the cloned one.
        $this->itemDefinition
            ->setFieldDefinition($this);
        // Reset the static cache of the field property definitions in order to
        // ensure that the clone will reference different field property definitions
        // objects.
        $this->propertyDefinitions = NULL;
    }
    
    /**
     * {@inheritdoc}
     */
    public function isInternal() {
        // All fields are not internal unless explicitly set.
        return !empty($this->definition['internal']);
    }

}