get_theme_file_uri( $file = '' ) {
	$file = ltrim( $file, '/' );

	if ( empty( $file ) ) {
		$url = get_stylesheet_directory_uri();
	} elseif ( file_exists( get_stylesheet_directory() . '/' . $file ) ) {
		$url = get_stylesheet_directory_uri() . '/' . $file;
	} else {
		$url = get_template_directory_uri() . '/' . $file;
	}

	/**
	 * Filters the URL to a file in the theme.
	 *
	 * @since 4.7.0
	 *
	 * @param string $url  The file URL.
	 * @param string $file The requested file to search for.
	 */
	return apply_filters( 'theme_file_uri', $url, $file );
}

/**
 * Retrieves the URL of a file in the parent theme.
 *
 * @since 4.7.0
 *
 * @param string $file Optional. File to return the URL for in the template directory.
 * @return string The URL of the file.
 */
function get_parent_theme_file_uri( $file = '' ) {
	$file = ltrim( $file, '/' );

	if ( empty( $file ) ) {
		$url = get_template_directory_uri();
	} else {
		$url = get_template_directory_uri() . '/' . $file;
	}

	/**
	 * Filters the URL to a file in the parent theme.
	 *
	 * @since 4.7.0
	 *
	 * @param string $url  The file URL.
	 * @param string $file The requested file to search for.
	 */
	return apply_filters( 'parent_theme_file_uri', $url, $file );
}

/**
 * Retrieves the path of a file in the theme.
 *
 * Searches in the stylesheet directory before the template directory so themes
 * which inherit from a parent theme can just override one file.
 *
 * @since 4.7.0
 *
 * @param string $file Optional. File to search for in the stylesheet directory.
 * @return string The path of the file.
 */
function get_theme_file_path( $file = '' ) {
	$file = ltrim( $file, '/' );

	if ( empty( $file ) ) {
		$path = get_stylesheet_directory();
	} elseif ( file_exists( get_stylesheet_directory() . '/' . $file ) ) {
		$path = get_stylesheet_directory() . '/' . $file;
	} else {
		$path = get_template_directory() . '/' . $file;
	}

	/**
	 * Filters the path to a file in the theme.
	 *
	 * @since 4.7.0
	 *
	 * @param string $path The file path.
	 * @param string $file The requested file to search for.
	 */
	return apply_filters( 'theme_file_path', $path, $file );
}

/**
 * Retrieves the path of a file in the parent theme.
 *
 * @since 4.7.0
 *
 * @param string $file Optional. File to return the path for in the template directory.
 * @return string The path of the file.
 */
function get_parent_theme_file_path( $file = '' ) {
	$file = ltrim( $file, '/' );

	if ( empty( $file ) ) {
		$path = get_template_directory();
	} else {
		$path = get_template_directory() . '/' . $file;
	}

	/**
	 * Filters the path to a file in the parent theme.
	 *
	 * @since 4.7.0
	 *
	 * @param string $path The file path.
	 * @param string $file The requested file to search for.
	 */
	return apply_filters( 'parent_theme_file_path', $path, $file );
}

/**
 * Retrieves the URL to the privacy policy page.
 *
 * @since 4.9.6
 *
 * @return string The URL to the privacy policy page. Empty string if it doesn't exist.
 */
function get_privacy_policy_url() {
	$url            = '';
	$policy_page_id = (int) get_option( 'wp_page_for_privacy_policy' );

	if ( ! empty( $policy_page_id ) && get_post_status( $policy_page_id ) === 'publish' ) {
		$url = (string) get_permalink( $policy_page_id );
	}

	/**
	 * Filters the URL of the privacy policy page.
	 *
	 * @since 4.9.6
	 *
	 * @param string $url            The URL to the privacy policy page. Empty string
	 *                               if it doesn't exist.
	 * @param int    $policy_page_id The ID of privacy policy page.
	 */
	return apply_filters( 'privacy_policy_url', $url, $policy_page_id );
}

/**
 * Displays the privacy policy link with formatting, when applicable.
 *
 * @since 4.9.6
 *
 * @param string $before Optional. Display before privacy policy link. Default empty.
 * @param string $after  Optional. Display after privacy policy link. Default empty.
 */
function the_privacy_policy_link( $before = '', $after = '' ) {
	echo get_the_privacy_policy_link( $before, $after );
}

/**
 * Returns the privacy policy link with formatting, when applicable.
 *
 * @since 4.9.6
 *
 * @param string $before Optional. Display before privacy policy link. Default empty.
 * @param string $after  Optional. Display after privacy policy link. Default empty.
 *
 * @return string Markup for the link and surrounding elements. Empty string if it
 *                doesn't exist.
 */
function get_the_privacy_policy_link( $before = '', $after = '' ) {
	$link               = '';
	$privacy_policy_url = get_privacy_policy_url();
	$policy_page_id     = (int) get_option( 'wp_page_for_privacy_policy' );
	$page_title         = ( $policy_page_id ) ? get_the_title( $policy_page_id ) : '';

	if ( $privacy_policy_url && $page_title ) {
		$link = sprintf(
			'<a class="privacy-policy-link" href="%s">%s</a>',
			esc_url( $privacy_policy_url ),
			esc_html( $page_title )
		);
	}

	/**
	 * Filters the privacy policy link.
	 *
	 * @since 4.9.6
	 *
	 * @param string $link               The privacy policy link. Empty string if it
	 *                                   doesn't exist.
	 * @param string $privacy_policy_url The URL of the privacy policy. Empty string
	 *                                   if it doesn't exist.
	 */
	$link = apply_filters( 'the_privacy_policy_link', $link, $privacy_policy_url );

	if ( $link ) {
		return $before . $link . $after;
	}

	return '';
}