protected function add_crumbs_single( $post_id = 0, $permalink = '' ) {
		if ( ! $post_id ) {
			global $post;
		} else {
			$post = get_post( $post_id ); // WPCS: override ok.
		}

		if ( ! $permalink ) {
			$permalink = get_permalink( $post );
		}

		if ( 'product' === get_post_type( $post ) ) {
			$this->prepend_shop_page();

			$terms = wc_get_product_terms(
				$post->ID,
				'product_cat',
				apply_filters(
					'woocommerce_breadcrumb_product_terms_args',
					array(
						'orderby' => 'parent',
						'order'   => 'DESC',
					)
				)
			);

			if ( $terms ) {
				$main_term = apply_filters( 'woocommerce_breadcrumb_main_term', $terms[0], $terms );
				$this->term_ancestors( $main_term->term_id, 'product_cat' );
				$this->add_crumb( $main_term->name, get_term_link( $main_term ) );
			}
		} elseif ( 'post' !== get_post_type( $post ) ) {
			$post_type = get_post_type_object( get_post_type( $post ) );

			if ( ! empty( $post_type->has_archive ) ) {
				$this->add_crumb( $post_type->labels->singular_name, get_post_type_archive_link( get_post_type( $post ) ) );
			}
		} else {
			$cat = current( get_the_category( $post ) );
			if ( $cat ) {
				$this->term_ancestors( $cat->term_id, 'category' );
				$this->add_crumb( $cat->name, get_term_link( $cat ) );
			}
		}

		$this->add_crumb( get_the_title( $post ), $permalink );
	}