<?php

/**

 * Elements styles block support.

 *

 * @package WordPress

 * @since 5.8.0

 */

/**

 * Render the elements stylesheet.

 *

 * @since 5.8.0

 * @access private

 *

 * @param  string $block_content Rendered block content.

 * @param  array  $block         Block object.

 * @return string                Filtered block content.

 */

function wp_render_elements_support( $block_content, $block ) {

	$link_color = null;

	if ( ! empty( $block['attrs'] ) ) {

		$link_color = _wp_array_get( $block['attrs'], array( 'style', 'elements', 'link', 'color', 'text' ), null );

	}

	/*

	* For now we only care about link color.

	* This code in the future when we have a public API

	* should take advantage of WP_Theme_JSON::compute_style_properties

	* and work for any element and style.

	*/

	if ( null === $link_color ) {

		return $block_content;

	}

	$class_name = 'wp-elements-' . uniqid();

	if ( strpos( $link_color, 'var:preset|color|' ) !== false ) {

		// Get the name from the string and add proper styles.

		$index_to_splice = strrpos( $link_color, '|' ) + 1;

		$link_color_name = substr( $link_color, $index_to_splice );

		$link_color      = "var(--wp--preset--color--$link_color_name)";

	}

	$link_color_declaration = esc_html( safecss_filter_attr( "color: $link_color" ) );

	$style = "<style>.$class_name a{" . $link_color_declaration . " !important;}</style>\n";

	// Like the layout hook this assumes the hook only applies to blocks with a single wrapper.

	// Retrieve the opening tag of the first HTML element.

	$html_element_matches = array();

	preg_match( '/<[^>]+>/', $block_content, $html_element_matches, PREG_OFFSET_CAPTURE );

	$first_element = $html_element_matches[0][0];

	// If the first HTML element has a class attribute just add the new class

	// as we do on layout and duotone.

	if ( strpos( $first_element, 'class="' ) !== false ) {

		$content = preg_replace(

			'/' . preg_quote( 'class="', '/' ) . '/',

			'class="' . $class_name . ' ',

			$block_content,

			1

		);

	} else {

		// If the first HTML element has no class attribute we should inject the attribute before the attribute at the end.

		$first_element_offset = $html_element_matches[0][1];

		$content              = substr_replace( $block_content, ' class="' . $class_name . '"', $first_element_offset + strlen( $first_element ) - 1, 0 );

	}

	return $content . $style;

}

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