<?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 );