using System;
using System.Numerics;
using System.Runtime.InteropServices;
using FFXIVClientStructs.FFXIV.Client.Graphics.Kernel;
using FFXIVClientStructs.FFXIV.Client.Graphics.Render;
using TerraFX.Interop.DirectX;

namespace Auspex.Rendering.Direct3D;

internal sealed class SceneDepthCapture : IDisposable
{
	private unsafe ID3D11Texture2D* _copy;

	private unsafe ID3D11ShaderResourceView* _copySRV;

	private uint _copyWidth;

	private uint _copyHeight;

	public unsafe ID3D11ShaderResourceView* SRV => _copySRV;

	public Vector2 UvScale { get; private set; } = new Vector2(1f, 1f);

	public bool IsResolutionScaled { get; private set; }

	public unsafe void Dispose()
	{
		if (_copySRV != null)
		{
			_copySRV->Release();
			_copySRV = null;
		}
		if (_copy != null)
		{
			_copy->Release();
			_copy = null;
		}
		GC.SuppressFinalize(this);
	}

	internal unsafe void Update()
	{
		RenderTargetManager* ptr = RenderTargetManager.Instance();
		Texture* ptr2 = ((ptr != null) ? ptr->DepthStencil : null);
		if (ptr2 == null || ptr2->D3D11Texture2D == null)
		{
			AuspexService.Log.Warning("[Auspex] SceneDepthCapture: scene depth source unavailable.");
			return;
		}
		Device* ptr3 = Device.Instance();
		IsResolutionScaled = ptr2->ActualWidth != ptr3->Width || ptr2->ActualHeight != ptr3->Height;
		ID3D11Texture2D* d3D11Texture2D = (ID3D11Texture2D*)ptr2->D3D11Texture2D;
		D3D11_TEXTURE2D_DESC srcDesc = default(D3D11_TEXTURE2D_DESC);
		d3D11Texture2D->GetDesc(&srcDesc);
		EnsureCopy(srcDesc);
		ID3D11DeviceContext* ptr4 = default(ID3D11DeviceContext*);
		((ID3D11Device*)ptr3->D3D11Forwarder)->GetImmediateContext(&ptr4);
		ptr4->CopyResource((ID3D11Resource*)_copy, (ID3D11Resource*)d3D11Texture2D);
		ptr4->Release();
		UvScale = new Vector2((ptr2->AllocatedWidth != 0) ? ((float)ptr2->ActualWidth / (float)ptr2->AllocatedWidth) : 1f, (ptr2->AllocatedHeight != 0) ? ((float)ptr2->ActualHeight / (float)ptr2->AllocatedHeight) : 1f);
	}

	private unsafe void EnsureCopy(D3D11_TEXTURE2D_DESC srcDesc)
	{
		if (_copy == null || _copyWidth != srcDesc.Width || _copyHeight != srcDesc.Height)
		{
			if (_copySRV != null)
			{
				_copySRV->Release();
				_copySRV = null;
			}
			if (_copy != null)
			{
				_copy->Release();
				_copy = null;
			}
			ID3D11Device* d3D11Forwarder = (ID3D11Device*)Device.Instance()->D3D11Forwarder;
			D3D11_TEXTURE2D_DESC d3D11_TEXTURE2D_DESC = srcDesc;
			d3D11_TEXTURE2D_DESC.Format = DXGI_FORMAT.DXGI_FORMAT_R24G8_TYPELESS;
			d3D11_TEXTURE2D_DESC.BindFlags = 8u;
			ID3D11Texture2D* copy = default(ID3D11Texture2D*);
			Marshal.ThrowExceptionForHR(d3D11Forwarder->CreateTexture2D(&d3D11_TEXTURE2D_DESC, null, &copy));
			_copy = copy;
			_copyWidth = srcDesc.Width;
			_copyHeight = srcDesc.Height;
			D3D11_SHADER_RESOURCE_VIEW_DESC d3D11_SHADER_RESOURCE_VIEW_DESC = new D3D11_SHADER_RESOURCE_VIEW_DESC
			{
				Format = DXGI_FORMAT.DXGI_FORMAT_R24_UNORM_X8_TYPELESS,
				ViewDimension = D3D_SRV_DIMENSION.D3D_SRV_DIMENSION_TEXTURE2D
			};
			d3D11_SHADER_RESOURCE_VIEW_DESC.Texture2D.MostDetailedMip = 0u;
			d3D11_SHADER_RESOURCE_VIEW_DESC.Texture2D.MipLevels = 1u;
			ID3D11ShaderResourceView* copySRV = default(ID3D11ShaderResourceView*);
			Marshal.ThrowExceptionForHR(d3D11Forwarder->CreateShaderResourceView((ID3D11Resource*)_copy, &d3D11_SHADER_RESOURCE_VIEW_DESC, &copySRV));
			_copySRV = copySRV;
		}
	}
}