<?php

/**

 * Server-side rendering of the `core/comment-template` block.

 *

 * @package WordPress

 */

/**

 * Function that recursively renders a list of nested comments.

 *

 * @global int $comment_depth

 *

 * @param WP_Comment[] $comments        The array of comments.

 * @param WP_Block     $block           Block instance.

 * @return string

 */

function block_core_comment_template_render_comments( $comments, $block ) {

	global $comment_depth;

	if ( empty( $comment_depth ) ) {

		$comment_depth = 1;

	}

	$content = '';

	foreach ( $comments as $comment ) {

		$children = $comment->get_children();

		/*

		 * We need to create the CSS classes BEFORE recursing into the children.

		 * This is because comment_class() uses globals like `$comment_alt`

		 * and `$comment_thread_alt` which are order-sensitive.

		 *

		 * The `false` parameter at the end means that we do NOT want the function

		 * to `echo` the output but to return a string.

		 * See https://developer.wordpress.org/reference/functions/comment_class/#parameters.

		 */

		$comment_classes = comment_class( '', $comment->comment_ID, $comment->comment_post_ID, false );

		// If the comment has children, recurse to create the HTML for the nested

		// comments.

		}

		$content .= sprintf( '<li id="comment-%1$s" %2$s>%3$s</li>', $comment->comment_ID, $comment_classes, $block_content );

	}

	return $content;

}

/**

 * Renders the `core/comment-template` block on the server.

 *

 * @param array    $attributes Block attributes.

 * @param string   $content    Block default content.

 * @param WP_Block $block      Block instance.

 *

 * @return string Returns the HTML representing the comments using the layout

 * defined by the block's inner blocks.

 */

function render_block_core_comment_template( $attributes, $content, $block ) {

	// Bail out early if the post ID is not set for some reason.

	if ( empty( $block->context['postId'] ) ) {

		return '';

	}

	if ( post_password_required( $block->context['postId'] ) ) {

		return;

	}

	$comment_query = new WP_Comment_Query(

		build_comment_query_vars_from_block( $block )

	);

	// Get an array of comments for the current post.

	$comments = $comment_query->get_comments();

	if ( count( $comments ) === 0 ) {

		return '';

	}

	$comment_order = get_option( 'comment_order' );

	if ( 'desc' === $comment_order ) {

		$comments = array_reverse( $comments );

	}

	$wrapper_attributes = get_block_wrapper_attributes();

	return sprintf(

		'<ol %1$s>%2$s</ol>',

		$wrapper_attributes,

		block_core_comment_template_render_comments( $comments, $block )

	);

}

/**

 * Registers the `core/comment-template` block on the server.

 */

function register_block_core_comment_template() {

	register_block_type_from_metadata(

		__DIR__ . '/comment-template',

		array(

			'render_callback'   => 'render_block_core_comment_template',

			'skip_inner_blocks' => true,

		)

	);

}

add_action( 'init', 'register_block_core_comment_template' );