wp_ajax_replyto_comment( string $action )

function wp_ajax_replyto_comment( $action ) {
	if ( empty( $action ) )
		$action = 'replyto-comment';

	check_ajax_referer( $action, '_ajax_nonce-replyto-comment' );

	$comment_post_ID = (int) $_POST['comment_post_ID'];
	$post = get_post( $comment_post_ID );
	if ( ! $post )
		wp_die( -1 );

	if ( !current_user_can( 'edit_post', $comment_post_ID ) )
		wp_die( -1 );

	if ( empty( $post->post_status ) )
		wp_die( 1 );
	elseif ( in_array($post->post_status, array('draft', 'pending', 'trash') ) )
		wp_die( __('ERROR: you are replying to a comment on a draft post.') );

	$user = wp_get_current_user();
	if ( $user->exists() ) {
		$user_ID = $user->ID;
		$comment_author       = wp_slash( $user->display_name );
		$comment_author_email = wp_slash( $user->user_email );
		$comment_author_url   = wp_slash( $user->user_url );
		$comment_content      = trim( $_POST['content'] );
		$comment_type         = isset( $_POST['comment_type'] ) ? trim( $_POST['comment_type'] ) : '';
		if ( current_user_can( 'unfiltered_html' ) ) {
			if ( ! isset( $_POST['_wp_unfiltered_html_comment'] ) )
				$_POST['_wp_unfiltered_html_comment'] = '';

			if ( wp_create_nonce( 'unfiltered-html-comment' ) != $_POST['_wp_unfiltered_html_comment'] ) {
				kses_remove_filters(); // start with a clean slate
				kses_init_filters(); // set up the filters
				remove_filter( 'pre_comment_content', 'wp_filter_post_kses' );
				add_filter( 'pre_comment_content', 'wp_filter_kses' );
			}
		}
	} else {
		wp_die( __( 'Sorry, you must be logged in to reply to a comment.' ) );
	}

	if ( '' == $comment_content )
		wp_die( __( 'ERROR: please type a comment.' ) );

	$comment_parent = 0;
	if ( isset( $_POST['comment_ID'] ) )
		$comment_parent = absint( $_POST['comment_ID'] );
	$comment_auto_approved = false;
	$commentdata = compact('comment_post_ID', 'comment_author', 'comment_author_email', 'comment_author_url', 'comment_content', 'comment_type', 'comment_parent', 'user_ID');

	// Automatically approve parent comment.
	if ( !empty($_POST['approve_parent']) ) {
		$parent = get_comment( $comment_parent );

		if ( $parent && $parent->comment_approved === '0' && $parent->comment_post_ID == $comment_post_ID ) {
			if ( ! current_user_can( 'edit_comment', $parent->comment_ID ) ) {
				wp_die( -1 );
			}

			if ( wp_set_comment_status( $parent, 'approve' ) )
				$comment_auto_approved = true;
		}
	}

	$comment_id = wp_new_comment( $commentdata );

	if ( is_wp_error( $comment_id ) ) {
		wp_die( $comment_id->get_error_message() );
	}

	$comment = get_comment($comment_id);
	if ( ! $comment ) wp_die( 1 );

	$position = ( isset($_POST['position']) && (int) $_POST['position'] ) ? (int) $_POST['position'] : '-1';

	ob_start();
	if ( isset( $_REQUEST['mode'] ) && 'dashboard' == $_REQUEST['mode'] ) {
		require_once( ABSPATH . 'wp-admin/includes/dashboard.php' );
		_wp_dashboard_recent_comments_row( $comment );
	} else {
		if ( isset( $_REQUEST['mode'] ) && 'single' == $_REQUEST['mode'] ) {
			$wp_list_table = _get_list_table('WP_Post_Comments_List_Table', array( 'screen' => 'edit-comments' ) );
		} else {
			$wp_list_table = _get_list_table('WP_Comments_List_Table', array( 'screen' => 'edit-comments' ) );
		}
		$wp_list_table->single_row( $comment );
	}
	$comment_list_item = ob_get_clean();

	$response =  array(
		'what' => 'comment',
		'id' => $comment->comment_ID,
		'data' => $comment_list_item,
		'position' => $position
	);

	$counts = wp_count_comments();
	$response['supplemental'] = array(
		'in_moderation' => $counts->moderated,
		'i18n_comments_text' => sprintf(
			_n( '%s Comment', '%s Comments', $counts->approved ),
			number_format_i18n( $counts->approved )
		),
		'i18n_moderation_text' => sprintf(
			_nx( '%s in moderation', '%s in moderation', $counts->moderated, 'comments' ),
			number_format_i18n( $counts->moderated )
		)
	);

	if ( $comment_auto_approved ) {
		$response['supplemental']['parent_approved'] = $parent->comment_ID;
		$response['supplemental']['parent_post_id'] = $parent->comment_post_ID;
	}

	$x = new WP_Ajax_Response();
	$x->add( $response );
	$x->send();
}