namespace ytLive.Services.Encoder;

/// <summary>
/// Picks the best available H.264 encoder from ffmpeg's <c>-encoders</c> listing,
/// honoring the license posture (no GPL libx264): hardware NVENC → QSV → AMF, then
/// the OpenH264 software fallback. Pure parser — the <c>-encoders</c> probe output is
/// fetched by the encoder via an <see cref="IEncoderProcess"/> and fed here.
/// </summary>
public static class FfmpegEncoderPicker
{
    /// <summary>Preference order, best first. All ship in the pinned BtbN lgpl-shared build.</summary>
    public static readonly string[] Preference =
    [
        "h264_nvenc",
        "h264_qsv",
        "h264_amf",
        "libopenh264",
    ];

    /// <summary>
    /// First <see cref="Preference"/> entry present in the probe output, or the
    /// software fallback (which the pinned build always contains) if none matched.
    /// Never returns libx264 — it is GPL and would contaminate the paid product.
    /// </summary>
    public static string Pick(string probeOutput)
    {
        var available = probeOutput.Split('\n');
        foreach (var name in Preference)
        {
            if (available.Any(line => line.Contains(name, StringComparison.Ordinal)))
                return name;
        }
        return Preference[^1];
    }
}