<?php
/**
 * Stateless, site-bound form capabilities. These contain no access credentials.
 *
 * @package Waitlistize
 */
namespace Waitlistize\Rest;

use Waitlistize\Api\PublicBooking;
use WP_Error;

final class BookingTicket {
	public static function issue( array $data ): string {
		$payload = self::encode( wp_json_encode( $data ) );
		return $payload . '.' . hash_hmac( 'sha256', $payload, wp_salt( 'auth' ) . ':' . get_current_blog_id() );
	}

	public static function read( mixed $ticket, string $kind ): array|WP_Error {
		if ( ! is_string( $ticket ) || strlen( $ticket ) > 4096 || ! preg_match( '/\A([A-Za-z0-9_-]+)\.([a-f0-9]{64})\z/', $ticket, $parts ) || ! hash_equals( hash_hmac( 'sha256', $parts[1], wp_salt( 'auth' ) . ':' . get_current_blog_id() ), $parts[2] ) ) {
			return PublicBooking::error( 'booking_ticket', 403 );
		}
		// phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_decode -- Signed JSON transport, never executable code.
		$data = json_decode( (string) base64_decode( strtr( $parts[1], '-_', '+/' ), true ), true );
		return is_array( $data ) && ( $data['kind'] ?? '' ) === $kind && ( $data['expires'] ?? 0 ) > time() ? $data : PublicBooking::error( 'booking_ticket', 403 );
	}

	private static function encode( string $data ): string {
		// phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_encode -- Signed JSON transport, never executable code.
		return rtrim( strtr( base64_encode( $data ), '+/', '-_' ), '=' );
	}
}