using System;
using System.Runtime.InteropServices;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;

using NVStreamline;

namespace NVStreamline
{
    [AddComponentMenu("NVIDIA/Streamline DLSS-G HDRP")]
    public class StreamlineDLSSGHDRP : MonoBehaviour
    {
        private Camera m_camera;
        private uint m_id;
        public bool DLSSGFeatureAvailable { get; private set; } = false;

#if false
        //Put 5x3Compute shader in test project and drag onto this in editor
        public ComputeShader TESTcs5x3 = null;

        public ComputeShader GetFont5x3Shader()
        {
            return TESTcs5x3;
        }
#endif

        public void SetupDepthAndMVecTextureTags(CommandBuffer cmd, int frameCount)
        {
            uint frameIndex = (uint)frameCount;
            if (StreamlineDLSSGCore.DLSSGEnabled)
            {
                RenderTexture targetDepth = StreamlineDLSSGCore.GetTargetDepthTexture();
                RenderTexture targetMVecs = StreamlineDLSSGCore.GetTargetMVecsTexture();

                StreamlineCore.SetTag(cmd, frameIndex, m_id, targetDepth, StreamlineCore.BufferType.eBufferTypeDepth, 0);
                StreamlineCore.SetTag(cmd, frameIndex, m_id, targetMVecs, StreamlineCore.BufferType.eBufferTypeMVec, 0);
            }
            else
            {
                StreamlineCore.SetTag(cmd, frameIndex, m_id, null, StreamlineCore.BufferType.eBufferTypeDepth, 0);
                StreamlineCore.SetTag(cmd, frameIndex, m_id, null, StreamlineCore.BufferType.eBufferTypeMVec, 0);
            }
        }

        public void SetupHudlessColorTextureTags(CommandBuffer cmd, int frameCount)
        {
            uint frameIndex = (uint)frameCount;
            if (StreamlineDLSSGCore.DLSSGEnabled && StreamlineDLSSGCore.UseHudlessColor)
            {
                RenderTexture targetHudlessColor = StreamlineDLSSGCore.GetTargetHudlessColorTexture();
                StreamlineCore.SetTag(cmd, frameIndex, m_id, targetHudlessColor, StreamlineCore.BufferType.eBufferTypeHUDLessColor, 0);
            }
            else
            {
                StreamlineCore.SetTag(cmd, frameIndex, m_id, null, StreamlineCore.BufferType.eBufferTypeHUDLessColor, 0);
            }
        }

        public void HDRPSetupDLSSGFeatureConstants(CommandBuffer cmdBuffer, Camera camera, int frameCount)
        {
            StreamlineDLSSGCore.SetupDLSSGFeatureConstants(cmdBuffer, camera, m_id, (uint)frameCount);
        }

        void Awake()
        {
            m_camera = GetComponent<Camera>();
            DLSSGFeatureAvailable = false;

            if (!StreamlineCore.IsFeatureSupported(StreamlineCore.Feature.eFeatureDLSS_G))
            {
                Debug.Log("DLSSG is not supported");
                return;
            }

            int id = StreamlineCore.CreateFeature(StreamlineCore.Feature.eFeatureDLSS_G);
            if (id != 0)  //CreateFeature must return 0 for DLSSG
            {
                Debug.LogError("DLSSG Awake FAILED to get feature id");
                return;
            }

            m_id = (uint)id;
            DLSSGFeatureAvailable = true;
        }

        void OnDestroy()
        {
            if (DLSSGFeatureAvailable && m_id == 0)
            {
                StreamlineCore.DestroyFeature((int)m_id);
            }
        }

        void OnEnable()
        {
        }

        void OnDisable()
        {
        }

        // Update is called once per frame
        void LateUpdate()
        {
            if (DLSSGFeatureAvailable)
            {
                StreamlineDLSSGCore.ProcessDisposals();

                if (StreamlineDLSSGCore.UpdateDrawRects(m_camera))
                {
                    //reallocate tagged textures
                    StreamlineDLSSGCore.TaggedTextureDimensions tdd = StreamlineDLSSGCore.GetTaggedTextureDimensionsRef();

                    StreamlineDLSSGCore.AllocateTextures(tdd.m_currentDrawRect, tdd.m_currentViewRect, false, tdd.m_desktopScale, true);
                }
            }
        }
    }
}