/**
     * @inheritdoc
     */
    protected function defineRules(): array
    {
        $rules = parent::defineRules();
        $rules[] = [['id', 'fieldLayoutId'], 'number', 'integerOnly' => true];
        $rules[] = [['name', 'handle'], 'trim'];
        $rules[] = [['name', 'handle'], 'required'];
        $rules[] = [['name', 'handle'], 'string', 'max' => 255];
        $rules[] = [
            ['handle'],
            HandleValidator::class,
            'reservedWords' => ['id', 'dateCreated', 'dateUpdated', 'uid', 'title'],
        ];

        if ($this->validateHandleUniqueness) {
            $rules[] = [
                ['handle'],
                UniqueValidator::class,
                'targetClass' => EntryTypeRecord::class,
                'targetAttribute' => 'handle',
                'message' => Craft::t('yii', '{attribute} "{value}" has already been taken.'),
            ];
        }

        $rules[] = [['fieldLayout'], 'validateFieldLayout'];

        return $rules;
    }

    /**
     * Validates the field layout.
     *
     * @since 3.7.0
     */
    public function validateFieldLayout(): void
    {
        $fieldLayout = $this->getFieldLayout();
        $fieldLayout->reservedFieldHandles = [
            'author',
            'authorId',
            'authorIds',
            'authors',
            'section',
            'sectionId',
            'type',
            'postDate',
        ];

        if (!$fieldLayout->validate()) {
            $this->addModelErrors($fieldLayout, 'fieldLayout');
        }
    }

    /**
     * Use the handle as the string representation.
     *
     * @return string
     */
    public function __toString(): string
    {
        return (string)$this->handle ?: static::class;
    }

    /**
     * @inheritdoc
     */
    public function getHandle(): ?string
    {
        return $this->handle;
    }

    /**
     * @inheritdoc
     */
    public function getFieldLayout(): FieldLayout
    {
        /** @var FieldLayoutBehavior $behavior */
        $behavior = $this->getBehavior('fieldLayout');
        return $behavior->getFieldLayout();
    }

    /**
     * @inheritdoc
     * @since 3.3.0
     */
    public function getFieldContext(): string
    {
        return 'global';
    }

    /**
     * @inheritdoc
     * @since 3.3.0
     */
    public function getEagerLoadingPrefix(): string
    {
        return $this->handle;
    }

    /**
     * @inheritdoc
     */
    public function getCpEditUrl(): ?string
    {
        if (!$this->id || !Craft::$app->getUser()->getIsAdmin()) {
            return null;
        }
        return UrlHelper::cpUrl("settings/entry-types/$this->id");
    }

    /**
     * Returns the entry type’s config.
     *
     * @return array
     * @since 3.5.0
     */
    public function getConfig(): array
    {
        $config = [
            'name' => $this->name,
            'handle' => $this->handle,
            'description' => $this->description ?: null,
            'icon' => $this->icon || $this->icon === '0' ? $this->icon : null,
            'color' => $this->color?->value,
            'uiLabelFormat' => $this->uiLabelFormat,
            'hasTitleField' => $this->hasTitleField,
            'titleTranslationMethod' => $this->titleTranslationMethod,
            'titleTranslationKeyFormat' => $this->titleTranslationKeyFormat ?: null,
            'titleFormat' => $this->titleFormat ?: null,
            'allowLineBreaksInTitles' => $this->allowLineBreaksInTitles,
            'showSlugField' => $this->showSlugField,
            'slugTranslationMethod' => $this->slugTranslationMethod,
            'slugTranslationKeyFormat' => $this->slugTranslationKeyFormat ?: null,
            'showStatusField' => $this->showStatusField,
        ];

        $fieldLayout = $this->getFieldLayout();

        if ($fieldLayoutConfig = $fieldLayout->getConfig()) {
            $config['fieldLayouts'] = [
                $fieldLayout->uid => $fieldLayoutConfig,
            ];
        }

        return $config;
    }

    /**
     * Returns the entry type’s usage info, possibly with name and handle override values.
     *
     * @return array
     * @since 5.6.0
     */
    public function getUsageConfig(): array
    {
        $config = ['uid' => $this->uid];
        if (isset($this->original)) {
            if ($this->name !== $this->original->name) {
                $config['name'] = $this->name;
            }
            if ($this->handle !== $this->original->handle) {
                $config['handle'] = $this->handle;
            }
            if ($this->description !== $this->original->description) {
                $config['description'] = $this->description;
            }
            if (isset($this->group)) {
                $config['group'] = $this->group;
            }
        }
        return $config;
    }

    /**
     * Returns an array of sections and custom fields that make use of this entry type.
     *
     * @return array<Section|ElementContainerFieldInterface>
     * @since 5.0.0
     */
    public function findUsages(): array
    {
        if (!isset($this->id)) {
            return [];
        }

        $usages = [];

        // Sections
        foreach (Craft::$app->getEntries()->getAllSections() as $section) {
            foreach ($section->getEntryTypes() as $entryType) {
                if ($entryType->id === $this->id) {
                    $usages[] = $section;
                    break;
                }
            }
        }

        // Fields
        $fieldsService = Craft::$app->getFields();
        foreach ($fieldsService->getNestedEntryFieldTypes() as $type) {
            /** @var ElementContainerFieldInterface[] $fields */
            $fields = $fieldsService->getFieldsByType($type);
            foreach ($fields as $field) {
                foreach ($field->getFieldLayoutProviders() as $provider) {
                    if ($provider instanceof EntryType && $provider->id === $this->id) {
                        $usages[] = $field;
                    }
                }
            }
        }

        return $usages;
    }
}
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