using System;

namespace UnityEngine.Rendering.HighDefinition.AMD
{
    public static class AMDUnityPlugin
    {
        // TODO: allow dynamic switching between plugins (including shutdown of previous plugin)
        internal static readonly UpscalerPlugin ActivePlugin = new FSR2Wrapper.FSR2WrapperUpscaler();

        public static bool Load() => ActivePlugin.Load();

        public static bool IsLoaded() => ActivePlugin.IsLoaded();
    }

    public abstract class UpscalerPlugin
    {
        public abstract bool Load();

        public abstract bool IsLoaded();
        
        public abstract GraphicsDevice CreateGraphicsDevice();
        
        public abstract GraphicsDevice device { get; }

        public virtual uint version => 0x00;
    }

    public abstract class GraphicsDevice
    {
        public static GraphicsDevice device => AMDUnityPlugin.ActivePlugin.device;

        public static uint version => AMDUnityPlugin.ActivePlugin.version;

        public static GraphicsDevice CreateGraphicsDevice()
        {
            return AMDUnityPlugin.ActivePlugin.CreateGraphicsDevice();
        }

        public abstract FSR2Context CreateFeature(CommandBuffer cmd, in FSR2CommandInitializationData initSettings);

        public abstract void DestroyFeature(CommandBuffer cmd, FSR2Context fsrContext);

        public abstract void ExecuteFSR2(CommandBuffer cmd, FSR2Context fsrContext, in FSR2TextureTable textures);

        public abstract bool GetRenderResolutionFromQualityMode(FSR2Quality qualityMode, uint displayWidth, uint displayHeight, out uint renderWidth, out uint renderHeight);

        public abstract float GetUpscaleRatioFromQualityMode(FSR2Quality qualityMode);
    }

    public abstract class FSR2Context
    {
        public abstract ref FSR2CommandInitializationData initData { get; }
        
        public abstract ref FSR2CommandExecutionData executeData { get; }
    }

    public struct FSR2CommandInitializationData
    {
        public uint displaySizeHeight;

        public uint displaySizeWidth;

        public FfxFsr2InitializationFlags ffxFsrFlags;

        public uint maxRenderSizeHeight;

        public uint maxRenderSizeWidth;

        public bool GetFlag(FfxFsr2InitializationFlags flag)
        {
            return (ffxFsrFlags & flag) == flag;
        }

        public void SetFlag(FfxFsr2InitializationFlags flag, bool value)
        {
            if (value)
                ffxFsrFlags |= flag;
            else
                ffxFsrFlags &= ~flag;
        }
    }

    [Flags]
    public enum FfxFsr2InitializationFlags
    {
        EnableHighDynamicRange = 1,
        EnableDisplayResolutionMotionVectors = 2,
        EnableMotionVectorsJitterCancellation = 4,
        DepthInverted = 8,
        EnableDepthInfinite = 16, // 0x00000010
        EnableAutoExposure = 32, // 0x00000020
        EnableDynamicResolution = 64, // 0x00000040
        EnableTexture1DUsage = 128, // 0x00000080
    }

    public struct FSR2TextureTable
    {
        public Texture biasColorMask;
        public Texture colorInput;
        public Texture colorOutput;
        public Texture depth;
        public Texture exposureTexture;
        public Texture motionVectors;
        public Texture reactiveMask;
        public Texture transparencyMask;
    }

    public enum FSR2Quality
    {
        NativeAA,
        UltraQuality,
        Quality,
        Balanced,
        Performance,
        UltraPerformance,
    }

    public struct FSR2CommandExecutionData
    {
        public float jitterOffsetX;
        public float jitterOffsetY;
        public float MVScaleX;
        public float MVScaleY;
        public uint renderSizeWidth;
        public uint renderSizeHeight;
        public int enableSharpening;
        public float sharpness;
        public float frameTimeDelta;
        public float preExposure;
        public int reset;
        public float cameraNear;
        public float cameraFar;
        public float cameraFovAngleVertical;
    }
}