<?php

/**

 * Elements styles block support.

 *

 * @package WordPress

 * @since 5.8.0

 */

/**

 * Gets the elements class names.

 *

 * @since 6.0.0

 * @access private

 *

 * @param array $block Block object.

 * @return string The unique class name.

 */

function wp_get_elements_class_name( $block ) {

	return 'wp-elements-' . md5( serialize( $block ) );

}

/**

 * Determines whether an elements class name should be added to the block.

 *

 * @since 6.6.0

 * @access private

 *

 * @param  array $block   Block object.

 * @param  array $options Per element type options e.g. whether to skip serialization.

 * @return boolean Whether the block needs an elements class name.

 */

function wp_should_add_elements_class_name( $block, $options ) {

	if ( ! isset( $block['attrs']['style']['elements'] ) ) {

		return false;

	}

	$element_color_properties = array(

		'button'  => array(

			'skip'  => isset( $options['button']['skip'] ) ? $options['button']['skip'] : false,

			'paths' => array(

				array( 'button', 'color', 'text' ),

				array( 'button', 'color', 'background' ),

				array( 'button', 'color', 'gradient' ),

			),

		),

		'link'    => array(

			'skip'  => isset( $options['link']['skip'] ) ? $options['link']['skip'] : false,

			'paths' => array(

				array( 'link', 'color', 'text' ),

				array( 'link', ':hover', 'color', 'text' ),

			),

		),

		'heading' => array(

			'skip'  => isset( $options['heading']['skip'] ) ? $options['heading']['skip'] : false,

			'paths' => array(

				array( 'heading', 'color', 'text' ),

				array( 'heading', 'color', 'background' ),

				array( 'heading', 'color', 'gradient' ),

				array( 'h1', 'color', 'text' ),

				array( 'h1', 'color', 'background' ),

				array( 'h1', 'color', 'gradient' ),

				array( 'h2', 'color', 'text' ),

				array( 'h2', 'color', 'background' ),

				array( 'h2', 'color', 'gradient' ),

				array( 'h3', 'color', 'text' ),

				array( 'h3', 'color', 'background' ),

				array( 'h3', 'color', 'gradient' ),

				array( 'h4', 'color', 'text' ),

				array( 'h4', 'color', 'background' ),

				array( 'h4', 'color', 'gradient' ),

				array( 'h5', 'color', 'text' ),

				array( 'h5', 'color', 'background' ),

				array( 'h5', 'color', 'gradient' ),

				array( 'h6', 'color', 'text' ),

				array( 'h6', 'color', 'background' ),

				array( 'h6', 'color', 'gradient' ),

			),

		),

	);

	$elements_style_attributes = $block['attrs']['style']['elements'];

	foreach ( $element_color_properties as $element_config ) {

		if ( $element_config['skip'] ) {

			continue;

		}

		foreach ( $element_config['paths'] as $path ) {

			if ( null !== _wp_array_get( $elements_style_attributes, $path, null ) ) {

				return true;

			}

		}

	}

	return false;

}

/**

 * Render the elements stylesheet and adds elements class name to block as required.

 *

 * In the case of nested blocks we want the parent element styles to be rendered before their descendants.

 * This solves the issue of an element (e.g.: link color) being styled in both the parent and a descendant:

 * we want the descendant style to take priority, and this is done by loading it after, in DOM order.

 *

 * @since 6.0.0

 * @since 6.1.0 Implemented the style engine to generate CSS and classnames.

 * @since 6.6.0 Element block support class and styles are generated via the `render_block_data` filter instead of `pre_render_block`.

 * @access private

 *

 * @param array $parsed_block The parsed block.

 * @return array The same parsed block with elements classname added if appropriate.

 */

function wp_render_elements_support_styles( $parsed_block ) {

	/*

	 * The generation of element styles and classname were moved to the

	 * `render_block_data` filter in 6.6.0 to avoid filtered attributes

	 * breaking the application of the elements CSS class.

	 *

	 * @see https://github.com/WordPress/gutenberg/pull/59535

	 *

	 * The change in filter means, the argument types for this function

	 * have changed and require deprecating.

	 */

	if ( is_string( $parsed_block ) ) {

		_deprecated_argument(

			__FUNCTION__,

			'6.6.0',

			__( 'Use as a `pre_render_block` filter is deprecated. Use with `render_block_data` instead.' )

		);

	}

	$block_type           = WP_Block_Type_Registry::get_instance()->get_registered( $parsed_block['blockName'] );

	$element_block_styles = isset( $parsed_block['attrs']['style']['elements'] ) ? $parsed_block['attrs']['style']['elements'] : null;

	if ( ! $element_block_styles ) {

		return $parsed_block;

	}

	$skip_link_color_serialization         = wp_should_skip_block_supports_serialization( $block_type, 'color', 'link' );

	$skip_heading_color_serialization      = wp_should_skip_block_supports_serialization( $block_type, 'color', 'heading' );

	$skip_button_color_serialization       = wp_should_skip_block_supports_serialization( $block_type, 'color', 'button' );

	$skips_all_element_color_serialization = $skip_link_color_serialization &&

		$skip_heading_color_serialization &&

		$skip_button_color_serialization;

	if ( $skips_all_element_color_serialization ) {

		return $parsed_block;

	}

	$options = array(

		'button'  => array( 'skip' => $skip_button_color_serialization ),

		'link'    => array( 'skip' => $skip_link_color_serialization ),

		'heading' => array( 'skip' => $skip_heading_color_serialization ),

	);

	if ( ! wp_should_add_elements_class_name( $parsed_block, $options ) ) {

		return $parsed_block;

	}

	$class_name         = wp_get_elements_class_name( $parsed_block );

	$updated_class_name = isset( $parsed_block['attrs']['className'] ) ? $parsed_block['attrs']['className'] . " $class_name" : $class_name;

	_wp_array_set( $parsed_block, array( 'attrs', 'className' ), $updated_class_name );

	// Generate element styles based on selector and store in style engine for enqueuing.

	$element_types = array(

		'button'  => array(

			'selector' => ".$class_name .wp-element-button, .$class_name .wp-block-button__link",

			'skip'     => $skip_button_color_serialization,

		),

		'link'    => array(

			'selector'       => ".$class_name a:where(:not(.wp-element-button))",

			'hover_selector' => ".$class_name a:where(:not(.wp-element-button)):hover",

			'skip'           => $skip_link_color_serialization,

		),

		'heading' => array(

			'selector' => ".$class_name h1, .$class_name h2, .$class_name h3, .$class_name h4, .$class_name h5, .$class_name h6",

			'skip'     => $skip_heading_color_serialization,

			'elements' => array( 'h1', 'h2', 'h3', 'h4', 'h5', 'h6' ),

		),

	);

	foreach ( $element_types as $element_type => $element_config ) {

		if ( $element_config['skip'] ) {

			continue;

		}

		$element_style_object = isset( $element_block_styles[ $element_type ] ) ? $element_block_styles[ $element_type ] : null;

		// Process primary element type styles.

		if ( $element_style_object ) {

			wp_style_engine_get_styles(

				$element_style_object,

				array(

					'selector' => $element_config['selector'],

					'context'  => 'block-supports',

				)

			);

			if ( isset( $element_style_object[':hover'] ) ) {

				wp_style_engine_get_styles(

					$element_style_object[':hover'],

					array(

						'selector' => $element_config['hover_selector'],

						'context'  => 'block-supports',

					)

				);

			}

		}

		// Process related elements e.g. h1-h6 for headings.

		if ( isset( $element_config['elements'] ) ) {

			foreach ( $element_config['elements'] as $element ) {

				$element_style_object = isset( $element_block_styles[ $element ] )

					? $element_block_styles[ $element ]

					: null;

				if ( $element_style_object ) {

					wp_style_engine_get_styles(

						$element_style_object,

						array(

							'selector' => ".$class_name $element",

							'context'  => 'block-supports',

						)

					);

				}

			}

		}

	}

	return $parsed_block;

}

/**

 * Ensure the elements block support class name generated, and added to

 * block attributes, in the `render_block_data` filter gets applied to the

 * block's markup.

 *

 * @see wp_render_elements_support_styles

 * @since 6.6.0

 *

 * @param  string $block_content Rendered block content.

 * @param  array  $block         Block object.

 * @return string                Filtered block content.

 */

function wp_render_elements_class_name( $block_content, $block ) {

	$class_string = $block['attrs']['className'] ?? '';

	preg_match( '/\bwp-elements-\S+\b/', $class_string, $matches );

	if ( empty( $matches ) ) {

		return $block_content;

	}

	$tags = new WP_HTML_Tag_Processor( $block_content );

	if ( $tags->next_tag() ) {

		$tags->add_class( $matches[0] );

	}

	return $tags->get_updated_html();

}

add_filter( 'render_block', 'wp_render_elements_class_name', 10, 2 );

add_filter( 'render_block_data', 'wp_render_elements_support_styles', 10, 1 );