<?php
/**
 * Jetpack Redirect package.
 *
 * @package  automattic/jetpack-redirect
 */

namespace Automattic\Jetpack;

/**
 * Class Redirect
 */
class Redirect {
	/**
	 * Constructor.
	 *
	 * Static-only class, so nothing here.
	 */
	private function __construct() {}

	/**
	 * Builds and returns an URL using the jetpack.com/redirect/ service
	 *
	 * If $source is a simple slug, it will be sent using the source query parameter. e.g. jetpack.com/redirect/?source=slug
	 *
	 * If $source is a full URL, starting with https://, it will be sent using the url query parameter. e.g. jetpack.com/redirect/?url=https://wordpress.com
	 *
	 * Note: if using full URL, query parameters and anchor must be passed in $args. Any querystring of url fragment in the URL will be discarded.
	 *
	 * @param string       $source The URL handler registered in the server or the full destination URL (starting with https://).
	 * @param array|string $args {
	 *    Optional. Additional arguments to build the url. This is not a complete list as any argument passed here will be sent to as a query parameter to the Redirect server. These parameters will not necessarily be passed over to the final destination URL. If you want to add a parameter to the final destination URL, use the `query` argument.
	 *
	 *    @type string  $site URL of the site; Default is current site.
	 *    @type string  $path Additional path to be appended to the URL.
	 *    @type string  $query Query parameters to be added to the final destination URL. should be in query string format (e.g. 'key=value&foo=bar').
	 *    @type string  $anchor Anchor to be added to the URL.
	 *    @type integer $u The user ID.
	 * }
	 *
	 * @return string The built URL
	 */
	public static function get_url( $source, $args = array() ) {

		$url         = 'https://jetpack.com/redirect/';
		$site_suffix = ( new Status() )->get_site_suffix();
		$args        = wp_parse_args( $args, array( 'site' => $site_suffix ) );

		$source_key = 'source';

		if ( 0 === strpos( $source, 'https://' ) ) {
			$source_key = 'url';
			$source_url = \wp_parse_url( $source );

			// discard any query and fragments.
			$source = 'https://' . $source_url['host'] . ( isset( $source_url['path'] ) ? $source_url['path'] : '' );
		}

		$to_be_added = array(
			$source_key => rawurlencode( $source ),
		);

		foreach ( $args as $arg_name => $arg_value ) {

			if ( empty( $arg_value ) ) {
				continue;
			}

			$to_be_added[ $arg_name ] = rawurlencode( $arg_value );

		}

		if ( ! empty( $to_be_added ) ) {
			$url = add_query_arg( $to_be_added, $url );
		}

		return $url;
	}
}