using ErsatzTV.FFmpeg.Format;

namespace ErsatzTV.FFmpeg.Encoder.Nvenc;

public class EncoderHevcNvenc : EncoderBase
{
    private readonly FrameState _currentState;
    private readonly Option<SubtitleInputFile> _maybeSubtitleInputFile;
    private readonly Option<WatermarkInputFile> _maybeWatermarkInputFile;

    public EncoderHevcNvenc(
        FrameState currentState,
        Option<WatermarkInputFile> maybeWatermarkInputFile,
        Option<SubtitleInputFile> maybeSubtitleInputFile)
    {
        _currentState = currentState;
        _maybeWatermarkInputFile = maybeWatermarkInputFile;
        _maybeSubtitleInputFile = maybeSubtitleInputFile;
    }

    public override string Name => "hevc_nvenc";
    public override StreamKind Kind => StreamKind.Video;

    // need to upload if we're still in software and a watermark is used
    public override string Filter
    {
        get
        {
            // only upload to hw if we need to overlay (watermark or subtitle)
            if (_currentState.FrameDataLocation == FrameDataLocation.Software)
            {
                bool isPictureSubtitle = _maybeSubtitleInputFile.Map(s => s.IsImageBased).IfNone(false);

                if (isPictureSubtitle || _maybeWatermarkInputFile.IsSome)
                {
                    return "hwupload_cuda";
                }
            }

            return string.Empty;
        }
    }

    public override FrameState NextState(FrameState currentState) => currentState with
    {
        VideoFormat = VideoFormat.Hevc,
        FrameDataLocation = FrameDataLocation.Hardware
    };
}