#include "pch.h"
#include "Renderer.h"
#include "App.h"
#include <DirectXColors.h>


bool Renderer::Initialize() {
	_logger = App::GetInstance()->GetLogger();
	if (!_InitD3D()) {
		return false;
	}

	return true;
}

void Renderer::Render() {
	ID3D11RenderTargetView* rtv = _backBufferRtv.Get();
	_d3dDC->OMSetRenderTargets(1, &rtv, nullptr);
	_d3dDC->ClearRenderTargetView(rtv, DirectX::Colors::MidnightBlue);

	_dxgiSwapChain->Present(0, 0);
}

bool Renderer::_InitD3D() {
	HRESULT hr;
	const SIZE hostSize = App::GetInstance()->GetHostWndSize();

	{
		UINT createDeviceFlags = 0;
#ifdef _DEBUG
		createDeviceFlags |= D3D11_CREATE_DEVICE_DEBUG;
#endif

		D3D_FEATURE_LEVEL featureLevels[] = {
			D3D_FEATURE_LEVEL_11_1
		};

		ComPtr<ID3D11Device> d3dDevice;
		ComPtr<ID3D11DeviceContext> d3dDC;
		D3D_FEATURE_LEVEL featureLevel;
		hr = D3D11CreateDevice(
			nullptr,
			D3D_DRIVER_TYPE_HARDWARE,
			nullptr,
			createDeviceFlags,
			featureLevels,
			1,
			D3D11_SDK_VERSION,
			&d3dDevice,
			&featureLevel,
			&d3dDC
		);
		if (FAILED(hr)) {
			SPDLOG_LOGGER_CRITICAL(_logger, fmt::sprintf("D3D11CreateDevice 失败\n\tHRESULT：0x%X", hr));
			return false;
		}
		SPDLOG_LOGGER_INFO(_logger, fmt::format("已创建 D3D Device\n\t功能级别：{}", featureLevel));

		hr = d3dDevice.As<ID3D11Device5>(&_d3dDevice);
		if (FAILED(hr)) {
			SPDLOG_LOGGER_CRITICAL(_logger, fmt::sprintf("获取 ID3D11Device5 失败\n\tHRESULT：0x%X", hr));
			return false;
		}

		hr = d3dDC.As<ID3D11DeviceContext4>(&_d3dDC);
		if (FAILED(hr)) {
			SPDLOG_LOGGER_CRITICAL(_logger, fmt::sprintf("获取 ID3D11DeviceContext4 失败\n\tHRESULT：0x%X", hr));
			return false;
		}
	}

	{
		ComPtr<IDXGIFactory2> dxgiFactory;

		hr = _d3dDevice.As<IDXGIDevice4>(&_dxgiDevice);
		if (FAILED(hr)) {
			SPDLOG_LOGGER_CRITICAL(_logger, fmt::sprintf("获取 IDXGIDevice 失败\n\tHRESULT：0x%X", hr));
			return false;
		}
		
		ComPtr<IDXGIAdapter> dxgiAdapter;
		hr = _dxgiDevice->GetAdapter(&dxgiAdapter);
		if (FAILED(hr)) {
			SPDLOG_LOGGER_CRITICAL(_logger, fmt::sprintf("获取 IDXGIAdapter 失败\n\tHRESULT：0x%X", hr));
			return false;
		}
		
		hr = dxgiAdapter->GetParent(IID_PPV_ARGS(&dxgiFactory));
		if (FAILED(hr)) {
			SPDLOG_LOGGER_CRITICAL(_logger, fmt::sprintf("获取 IDXGIFactory2 失败\n\tHRESULT：0x%X", hr));
			return false;
		}

		DXGI_SWAP_CHAIN_DESC1 sd = {};
		sd.Width = hostSize.cx;
		sd.Height = hostSize.cy;
		sd.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
		sd.SampleDesc.Count = 1;
		sd.SampleDesc.Quality = 0;
		sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
		sd.BufferCount = 2;
		sd.SwapEffect = DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL;

		hr = dxgiFactory->CreateSwapChainForHwnd(
			_d3dDevice.Get(),
			App::GetInstance()->GetHwndHost(),
			&sd,
			nullptr,
			nullptr,
			&_dxgiSwapChain
		);
		if (FAILED(hr)) {
			SPDLOG_LOGGER_CRITICAL(_logger, fmt::sprintf("创建交换链失败\n\tHRESULT：{0x%X", hr));
			return false;
		}
		
		hr = dxgiFactory->MakeWindowAssociation(App::GetInstance()->GetHwndHost(), DXGI_MWA_NO_ALT_ENTER);
		if (FAILED(hr)) {
			SPDLOG_LOGGER_ERROR(_logger, fmt::sprintf("MakeWindowAssociation 失败\n\tHRESULT：0x%X", hr));
		}
	}

	{
		ComPtr<ID3D11Texture2D> pBackBuffer;
		hr = _dxgiSwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
		if (FAILED(hr)) {
			SPDLOG_LOGGER_CRITICAL(_logger, fmt::sprintf("获取后缓冲区失败\n\tHRESULT：0x%X", hr));
			return false;
		}
		
		hr = _d3dDevice->CreateRenderTargetView(pBackBuffer.Get(), NULL, &_backBufferRtv);
		if (FAILED(hr)) {
			SPDLOG_LOGGER_CRITICAL(_logger, fmt::sprintf("创建后缓冲区的渲染目标视图失败\n\tHRESULT：0x%X", hr));
			return false;
		}
	}

	// 所有效果都使用三角形带拓扑
	_d3dDC->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP);

	SPDLOG_LOGGER_INFO(_logger, "Renderer 初始化完成");
	return true;
}

ComPtr<ID3D11SamplerState> Renderer::GetSampler(FilterType filterType) {
	if (filterType == FilterType::LINEAR) {
		if (!_linearSampler) {
			D3D11_SAMPLER_DESC desc{};
			desc.Filter = D3D11_FILTER_MIN_MAG_MIP_LINEAR;
			desc.AddressU = D3D11_TEXTURE_ADDRESS_CLAMP;
			desc.AddressV = D3D11_TEXTURE_ADDRESS_CLAMP;
			desc.AddressW = D3D11_TEXTURE_ADDRESS_CLAMP;
			desc.ComparisonFunc = D3D11_COMPARISON_NEVER;
			desc.MinLOD = 0;
			desc.MaxLOD = 0;
			HRESULT hr = _d3dDevice->CreateSamplerState(&desc, &_linearSampler);

			if (FAILED(hr)) {
				SPDLOG_LOGGER_ERROR(_logger, fmt::sprintf("创建 ID3D11SamplerState 出错\n\tHRESULT：0x%X", hr));
				return nullptr;
			} else {
				SPDLOG_LOGGER_INFO(_logger, "已创建 ID3D11SamplerState\n\tFilter：D3D11_FILTER_MIN_MAG_MIP_LINEAR");
			}
		}

		return _linearSampler;
	} else {
		if (!_pointSampler) {
			D3D11_SAMPLER_DESC desc{};
			desc.Filter = D3D11_FILTER_MIN_MAG_MIP_POINT;
			desc.AddressU = D3D11_TEXTURE_ADDRESS_CLAMP;
			desc.AddressV = D3D11_TEXTURE_ADDRESS_CLAMP;
			desc.AddressW = D3D11_TEXTURE_ADDRESS_CLAMP;
			desc.ComparisonFunc = D3D11_COMPARISON_NEVER;
			desc.MinLOD = 0;
			desc.MaxLOD = 0;
			HRESULT hr = _d3dDevice->CreateSamplerState(&desc, &_pointSampler);

			if (FAILED(hr)) {
				SPDLOG_LOGGER_ERROR(_logger, fmt::sprintf("创建 ID3D11SamplerState 出错\n\tHRESULT：0x%X", hr));
				return nullptr;
			} else {
				SPDLOG_LOGGER_INFO(_logger, "已创建 ID3D11SamplerState\n\tFilter：D3D11_FILTER_MIN_MAG_MIP_POINT");
			}
		}

		return _pointSampler;
	}
}