using ErsatzTV.FFmpeg.Environment;
using ErsatzTV.FFmpeg.Format;

namespace ErsatzTV.FFmpeg.Decoder;

public abstract class DecoderBase : IDecoder
{
    protected abstract FrameDataLocation OutputFrameDataLocation { get; }
    public IList<EnvironmentVariable> EnvironmentVariables => Array.Empty<EnvironmentVariable>();
    public IList<string> GlobalOptions => Array.Empty<string>();
    public virtual IList<string> InputOptions(InputFile inputFile) => new List<string> { "-c:v", Name };
    public IList<string> FilterOptions => Array.Empty<string>();
    public IList<string> OutputOptions => Array.Empty<string>();

    public virtual FrameState NextState(FrameState currentState) =>
        currentState with { FrameDataLocation = OutputFrameDataLocation };

    public abstract string Name { get; }
    public bool AppliesTo(AudioInputFile audioInputFile) => false;

    public bool AppliesTo(VideoInputFile videoInputFile) => true;

    public bool AppliesTo(ConcatInputFile concatInputFile) => false;

    protected static int InputBitDepth(InputFile inputFile)
    {
        var bitDepth = 8;

        if (inputFile is VideoInputFile videoInputFile)
        {
            foreach (VideoStream videoStream in videoInputFile.VideoStreams.HeadOrNone())
            {
                foreach (IPixelFormat pixelFormat in videoStream.PixelFormat)
                {
                    bitDepth = pixelFormat.BitDepth;
                }
            }
        }

        return bitDepth;
    }
}