<?php

/**

 * Generated classname block support flag.

 *

 * @package WordPress

 * @since 5.6.0

 */

/**

 * Get the generated classname from a given block name.

 *

 * @since 5.6.0

 *

 * @access private

 *

 * @param  string $block_name Block Name.

 * @return string Generated classname.

 */

function wp_get_block_default_classname( $block_name ) {

	// Generated HTML classes for blocks follow the `wp-block-{name}` nomenclature.

	// Blocks provided by WordPress drop the prefixes 'core/' or 'core-' (historically used in 'core-embed/').

	$classname = 'wp-block-' . preg_replace(

		'/^core-/',

		'',

		str_replace( '/', '-', $block_name )

	);

	/**

	 * Filters the default block className for server rendered blocks.

	 *

	 * @since 5.6.0

	 *

	 * @param string     $class_name The current applied classname.

	 * @param string     $block_name The block name.

	 */

	$classname = apply_filters( 'block_default_classname', $classname, $block_name );

	return $classname;

}

/**

 * Add the generated classnames to the output.

 *

 * @since 5.6.0

 *

 * @access private

 *

 * @param  WP_Block_Type $block_type       Block Type.

 *

 * @return array Block CSS classes and inline styles.

 */

function wp_apply_generated_classname_support( $block_type ) {

	$attributes                      = array();

	$has_generated_classname_support = block_has_support( $block_type, array( 'className' ), true );

	if ( $has_generated_classname_support ) {

		$block_classname = wp_get_block_default_classname( $block_type->name );

		if ( $block_classname ) {

			$attributes['class'] = $block_classname;

		}

	}

	return $attributes;

}

// Register the block support.

WP_Block_Supports::get_instance()->register(

	'generated-classname',

	array(

		'apply' => 'wp_apply_generated_classname_support',

	)

);