using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;

namespace ADOFAIRenderer.Util.FFmpeg
{
    [SuppressMessage("ReSharper", "InconsistentNaming")]
    public enum EncoderKind
    {
        Software,
        NVENC,
        AMF,
        QSV,
        VideoToolbox
    }
    
    [SuppressMessage("ReSharper", "InconsistentNaming")]
    internal sealed class VideoEncoder : IEquatable<VideoEncoder>
    {
        // ReSharper disable MemberCanBePrivate.Global
        
        // ── H.264 ──
        public static readonly VideoEncoder H264_NVENC = new("h264_nvenc", Codec.H264, GPUVendor.NVIDIA, EncoderKind.NVENC);
        public static readonly VideoEncoder H264_QSV = new("h264_qsv", Codec.H264, GPUVendor.Intel, EncoderKind.QSV);
        public static readonly VideoEncoder H264_AMF = new("h264_amf", Codec.H264, GPUVendor.AMD, EncoderKind.AMF);
        public static readonly VideoEncoder H264_VideoToolbox = new("h264_videotoolbox", Codec.H264, GPUVendor.Apple, EncoderKind.VideoToolbox);
        public static readonly VideoEncoder Libx264 = new("libx264", Codec.H264, GPUVendor.Unknown, EncoderKind.Software);

        // ── H.265 (HEVC) ──
        public static readonly VideoEncoder HEVC_NVENC = new("hevc_nvenc", Codec.H265, GPUVendor.NVIDIA, EncoderKind.NVENC);
        public static readonly VideoEncoder HEVC_QSV = new("hevc_qsv", Codec.H265, GPUVendor.Intel, EncoderKind.QSV);
        public static readonly VideoEncoder HEVC_AMF = new("hevc_amf", Codec.H265, GPUVendor.AMD, EncoderKind.AMF);
        public static readonly VideoEncoder HEVC_VideoToolbox = new("hevc_videotoolbox", Codec.H265, GPUVendor.Apple, EncoderKind.VideoToolbox);
        public static readonly VideoEncoder Libx265 = new("libx265", Codec.H265, GPUVendor.Unknown, EncoderKind.Software);

        // ── VP9 ──
        public static readonly VideoEncoder VP9_NVENC = new("vp9_nvenc", Codec.VP9, GPUVendor.NVIDIA, EncoderKind.NVENC);
        public static readonly VideoEncoder VP9_QSV = new("vp9_qsv", Codec.VP9, GPUVendor.Intel, EncoderKind.QSV);
        public static readonly VideoEncoder LibvpxVP9 = new("libvpx-vp9", Codec.VP9, GPUVendor.Unknown, EncoderKind.Software);

        // ── AV1 ──
        public static readonly VideoEncoder AV1_NVENC = new("av1_nvenc", Codec.AV1, GPUVendor.NVIDIA, EncoderKind.NVENC);
        public static readonly VideoEncoder AV1_QSV = new("av1_qsv", Codec.AV1, GPUVendor.Intel, EncoderKind.QSV);
        public static readonly VideoEncoder AV1_AMF = new("av1_amf", Codec.AV1, GPUVendor.AMD, EncoderKind.AMF);
        public static readonly VideoEncoder LibSvtAv1 = new("libsvtav1", Codec.AV1, GPUVendor.Unknown, EncoderKind.Software);
        public static readonly VideoEncoder LibAomAv1 = new("libaom-av1", Codec.AV1, GPUVendor.Unknown, EncoderKind.Software);

        // ── VVC ──
        public static readonly VideoEncoder LibVvenc = new("libvvenc", Codec.VVC, GPUVendor.Unknown, EncoderKind.Software);
        
        // ReSharper restore MemberCanBePrivate.Global

        public static readonly IReadOnlyList<VideoEncoder> All = new[]
        {
            H264_NVENC, H264_QSV, H264_AMF, H264_VideoToolbox, Libx264,
            HEVC_NVENC, HEVC_QSV, HEVC_AMF, HEVC_VideoToolbox, Libx265,
            VP9_NVENC, VP9_QSV, LibvpxVP9,
            AV1_NVENC, AV1_QSV, AV1_AMF, LibSvtAv1, LibAomAv1,
            LibVvenc
        };

        private static readonly Dictionary<string, VideoEncoder> ByName =
            All.ToDictionary(e => e.Name, StringComparer.OrdinalIgnoreCase);

        public string Name { get; }
        public Codec Codec { get; }
        public GPUVendor Vendor { get; }
        public EncoderKind Kind { get; }
        public bool IsHardware => Kind != EncoderKind.Software;

        private VideoEncoder(string name, Codec codec, GPUVendor vendor, EncoderKind kind)
        {
            Name = name;
            Codec = codec;
            Vendor = vendor;
            Kind = kind;
        }

        public static VideoEncoder? FromName(string name)
        {
            return string.IsNullOrEmpty(name) ? null : ByName.GetValueOrDefault(name);
        }

        public bool Equals(VideoEncoder other)
        {
            if (ReferenceEquals(null, other)) return false;
            return ReferenceEquals(this, other) || string.Equals(Name, other.Name, StringComparison.OrdinalIgnoreCase);
        }

        public override bool Equals(object? obj)
        {
            return ReferenceEquals(this, obj) || obj is VideoEncoder other && Equals(other);
        }

        public override int GetHashCode()
        {
            return StringComparer.OrdinalIgnoreCase.GetHashCode(Name);
        }

        public static bool operator ==(VideoEncoder left, VideoEncoder right)
        {
            return Equals(left, right);
        }

        public static bool operator !=(VideoEncoder left, VideoEncoder right)
        {
            return !Equals(left, right);
        }

        public override string ToString() => Name;
    }
}