using ErsatzTV.FFmpeg.Capabilities.Vaapi;
using ErsatzTV.FFmpeg.Format;
using Microsoft.Extensions.Logging;

namespace ErsatzTV.FFmpeg.Capabilities;

public class VaapiHardwareCapabilities : IHardwareCapabilities
{
    private readonly List<VaapiProfileEntrypoint> _profileEntrypoints;
    private readonly ILogger _logger;

    public VaapiHardwareCapabilities(List<VaapiProfileEntrypoint> profileEntrypoints, ILogger logger)
    {
        _profileEntrypoints = profileEntrypoints;
        _logger = logger;
    }

    public bool CanDecode(string videoFormat, Option<string> videoProfile, Option<IPixelFormat> maybePixelFormat)
    {
        int bitDepth = maybePixelFormat.Map(pf => pf.BitDepth).IfNone(8);

        bool result = (videoFormat, videoProfile.IfNone(string.Empty).ToLowerInvariant()) switch
        {
            // no hardware decoding of 10-bit h264
            (VideoFormat.H264, _) when bitDepth == 10 => false,
            
            // no hardware decoding of h264 baseline profile
            (VideoFormat.H264, "baseline" or "66") => false,
            
            (VideoFormat.H264, "main" or "77") =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.H264Main, VaapiEntrypoint.Decode)),

            (VideoFormat.H264, "high" or "100") =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.H264High, VaapiEntrypoint.Decode)),

            (VideoFormat.H264, "high 10" or "110") =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.H264High, VaapiEntrypoint.Decode)),

            (VideoFormat.H264, "baseline constrained" or "578") =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.H264ConstrainedBaseline, VaapiEntrypoint.Decode)),

            (VideoFormat.Mpeg2Video, "main" or "4") =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.Mpeg2Main, VaapiEntrypoint.Decode)),

            (VideoFormat.Mpeg2Video, "simple" or "5") =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.Mpeg2Simple, VaapiEntrypoint.Decode)),

            (VideoFormat.Vc1, "simple" or "0") =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.Vc1Simple, VaapiEntrypoint.Decode)),

            (VideoFormat.Vc1, "main" or "1") =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.Vc1Main, VaapiEntrypoint.Decode)),

            (VideoFormat.Vc1, "advanced" or "3") =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.Vc1Advanced, VaapiEntrypoint.Decode)),

            (VideoFormat.Hevc, "main" or "1") =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.HevcMain, VaapiEntrypoint.Decode)),

            (VideoFormat.Hevc, "main 10" or "2") =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.HevcMain10, VaapiEntrypoint.Decode)),

            // fall back to software decoder
            _ => false
        };

        if (!result)
        {
            _logger.LogDebug(
                "VAAPI does not support decoding {Format}/{Profile}, will use software decoder",
                videoFormat,
                videoProfile);
        }
        
        return result;
    }

    public bool CanEncode(string videoFormat, Option<string> videoProfile, Option<IPixelFormat> maybePixelFormat)
    {
        int bitDepth = maybePixelFormat.Map(pf => pf.BitDepth).IfNone(8);

        bool result = videoFormat switch
        {
            // vaapi cannot encode 10-bit h264
            VideoFormat.H264 when bitDepth == 10 => false,
            
            VideoFormat.H264 =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.H264Main, VaapiEntrypoint.Encode)),

            VideoFormat.Hevc when bitDepth == 10 =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.HevcMain10, VaapiEntrypoint.Encode)),

            VideoFormat.Hevc =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.HevcMain, VaapiEntrypoint.Encode)),

            VideoFormat.Mpeg2Video =>
                _profileEntrypoints.Contains(
                    new VaapiProfileEntrypoint(VaapiProfile.Mpeg2Main, VaapiEntrypoint.Encode)),
            
            _ => false
        };
        
        if (!result)
        {
            _logger.LogDebug(
                "VAAPI does not support encoding {Format} with bit depth {BitDepth}, will use software encoder",
                videoFormat,
                bitDepth);
        }

        return result;
    }
}