namespace Azaion.Missions.JwksMock.Services;

/// <summary>RFC 7515 §2 base64url (no padding) helpers.</summary>
public static class Base64Url
{
    public static string Encode(ReadOnlySpan<byte> input)
    {
        var b64 = Convert.ToBase64String(input);
        return b64.Replace('+', '-').Replace('/', '_').TrimEnd('=');
    }

    public static byte[] Decode(string input)
    {
        var s = input.Replace('-', '+').Replace('_', '/');
        var pad = s.Length % 4;
        if (pad > 0) s += new string('=', 4 - pad);
        return Convert.FromBase64String(s);
    }
}