%1$s %2$s %3$s %4$s Feed', 'all-in-one-seo-pack' ),
			// Translators: 1 - Blog name, 2 - Separator (raquo), 3 - Author name.
			'authortitle'   => __( '%1$s %2$s Posts by %3$s Feed', 'all-in-one-seo-pack' ),
			// Translators: 1 - Blog name, 2 - Separator (raquo), 3 - Search query.
			'searchtitle'   => __( '%1$s %2$s Search Results for “%3$s” Feed', 'all-in-one-seo-pack' ),
			// Translators: 1 - Blog name, 2 - Separator (raquo), 3 - Post type name.
			'posttypetitle' => __( '%1$s %2$s %3$s Feed', 'all-in-one-seo-pack' ),
		];

		$args       = wp_parse_args( $args, $defaults );
		$attributes = [
			'title' => null,
			'href'  => null
		];

		if (
			aioseo()->options->searchAppearance->advanced->crawlCleanup->feeds->postComments &&
			is_singular()
		) {
			$attributes = $this->getPostCommentsAttributes( $args );
		}

		$archives = aioseo()->options->searchAppearance->advanced->crawlCleanup->feeds->archives->included;
		$postType = $this->getTheQueriedPostType();
		if (
			(
				aioseo()->options->searchAppearance->advanced->crawlCleanup->feeds->archives->all ||
				in_array( $postType, $archives, true )
			) &&
			is_post_type_archive()
		) {
			$attributes = $this->getPostTypeArchivesAttributes( $args );
		}

		// All taxonomies.
		$taxonomies = aioseo()->options->searchAppearance->advanced->crawlCleanup->feeds->taxonomies->included;
		$term       = get_queried_object();
		if (
			$term &&
			isset( $term->taxonomy ) &&
			(
				aioseo()->options->searchAppearance->advanced->crawlCleanup->feeds->taxonomies->all ||
				in_array( $term->taxonomy, $taxonomies, true )
			) &&
			(
				is_category() ||
				is_tag() ||
				is_tax()
			)
		) {
			$attributes = $this->getTaxonomiesAttributes( $args, $term );
		}

		if (
			aioseo()->options->searchAppearance->advanced->crawlCleanup->feeds->authors &&
			is_author()
		) {
			$attributes = $this->getAuthorAttributes( $args );
		}

		if (
			aioseo()->options->searchAppearance->advanced->crawlCleanup->feeds->search &&
			is_search()
		) {
			$attributes = $this->getSearchAttributes( $args );
		}

		if ( ! empty( $attributes['title'] ) && ! empty( $attributes['href'] ) ) {
			echo '<link rel="alternate" type="application/rss+xml" title="' . esc_attr( $attributes['title'] ) . '" href="' . esc_url( $attributes['href'] ) . '" />' . "\n";
		}
	}

	/**
	 * Retrieve the attributes for post comments feed.
	 *
	 * @since 4.2.1
	 *
	 * @param  array $args An array of arguments.
	 * @return array       An array of attributes.
	 */
	private function getPostCommentsAttributes( $args ) {
		$id    = 0;
		$post  = get_post( $id );
		$title = null;
		$href  = null;

		if (
			comments_open() ||
			pings_open() ||
			0 < $post->comment_count
		) {
			$title = sprintf(
				$args['singletitle'],
				get_bloginfo( 'name' ),
				$args['separator'],
				the_title_attribute( [ 'echo' => false ] )
			);

			$href = get_post_comments_feed_link( $post->ID );
		}

		return [
			'title' => $title,
			'href'  => $href
		];
	}

	/**
	 * Retrieve the attributes for post type archives feed.
	 *
	 * @since 4.2.1
	 *
	 * @param  array $args An array of arguments.
	 * @return array       An array of attributes.
	 */
	private function getPostTypeArchivesAttributes( $args ) {
		$postTypeObject = get_post_type_object( $this->getQueriedPostType() );
		$title          = sprintf( $args['posttypetitle'], get_bloginfo( 'name' ), $args['separator'], $postTypeObject->labels->name );
		$href           = get_post_type_archive_feed_link( $postTypeObject->name );

		return [
			'title' => $title,
			'href'  => $href
		];
	}

	/**
	 * Retrieve the attributes for taxonomies feed.
	 *
	 * @since 4.2.1
	 *
	 * @param  array $args    An array of arguments.
	 * @param  \WP_Term $term The term.
	 * @return array          An array of attributes.
	 */
	private function getTaxonomiesAttributes( $args, $term ) {
		$title = null;
		$href  = null;

		if ( is_category() ) {
			$title = sprintf( $args['cattitle'], get_bloginfo( 'name' ), $args['separator'], $term->name );
			$href  = get_category_feed_link( $term->term_id );
		}

		if ( is_tag() ) {
			$title = sprintf( $args['tagtitle'], get_bloginfo( 'name' ), $args['separator'], $term->name );
			$href  = get_tag_feed_link( $term->term_id );
		}

		if ( is_tax() ) {
			$tax   = get_taxonomy( $term->taxonomy );
			$title = sprintf( $args['taxtitle'], get_bloginfo( 'name' ), $args['separator'], $term->name, $tax->labels->singular_name );
			$href  = get_term_feed_link( $term->term_id, $term->taxonomy );
		}

		return [
			'title' => $title,
			'href'  => $href
		];
	}

	/**
	 * Retrieve the attributes for the author feed.
	 *
	 * @since 4.2.1
	 *
	 * @param  array $args An array of arguments.
	 * @return array       An array of attributes.
	 */
	private function getAuthorAttributes( $args ) {
		$authorId = (int) get_query_var( 'author' );
		$title    = sprintf( $args['authortitle'], get_bloginfo( 'name' ), $args['separator'], get_the_author_meta( 'display_name', $authorId ) );
		$href     = get_author_feed_link( $authorId );

		return [
			'title' => $title,
			'href'  => $href
		];
	}

	/**
	 * Retrieve the attributes for the search feed.
	 *
	 * @since 4.2.1
	 *
	 * @param  array $args An array of arguments.
	 * @return array       An array of attributes.
	 */
	private function getSearchAttributes( $args ) {
		$title = sprintf( $args['searchtitle'], get_bloginfo( 'name' ), $args['separator'], get_search_query( false ) );
		$href  = get_search_feed_link();

		return [
			'title' => $title,
			'href'  => $href
		];
	}

	/**
	 * Get the currently queried post type.
	 *
	 * @since 4.2.1
	 *
	 * @return string The currently queried post type.
	 */
	private function getQueriedPostType() {
		$postType = get_query_var( 'post_type' );
		if ( is_array( $postType ) ) {
			$postType = reset( $postType );
		}

		return $postType;
	}
}