namespace HSchool.Protocol;

/// <summary>Wire-format constants shared by the server and the browser client.</summary>
public static class ProtocolConstants
{
    /// <summary>Bumped on every breaking change to the binary layout.</summary>
    public const byte Version = 9;

    /// <summary>Upper bound for a single WebSocket frame accepted by the server.</summary>
    public const int MaxMessageSize = 8 * 1024;

    /// <summary>Hello locale byte: Russian. Any other value that is not <see cref="LocaleEnglish"/> is treated as this.</summary>
    public const byte LocaleRussian = 0;

    /// <summary>Hello locale byte: English. Same value the catalog HTTP API takes as <c>lang=en</c>.</summary>
    public const byte LocaleEnglish = 1;

    /// <summary>Catalog locale string matching the Hello byte. Unknown bytes fall back to Russian.</summary>
    public static string CatalogLocale(byte locale) =>
        locale == LocaleEnglish ? "en" : "ru";
}