#include "D3D12Core.h"
#include "D3D12CommonHeader.h"

using namespace Microsoft::WRL;
namespace XEngine::graphics::d3d12::core {
namespace {

/**
 * @brief 主 Direct3D 12 设备指针
 * @details 指向 Direct3D 12 设备的智能指针，用于创建渲染管线、管理资源与 GPU 命令
 */
ID3D12Device8* main_device{ nullptr };

/**
 * @brief DXGI 工厂指针
 * @details 指向 DXGI 工厂的智能指针，用于创建 Direct3D 12 设备
 */
IDXGIFactory7* dxgi_factory{ nullptr };

// 最小支持的 Direct3D 特本级别
constexpr D3D_FEATURE_LEVEL minumum_feature_level{ D3D_FEATURE_LEVEL_11_0 };

bool
failed_init()
{
	shutdown();
	return false;
}

/**
 * @brief 确定要使用的 GPU
 * @details 枚举所有可用的 GPU，选择支持最小特征级别的 Direct3D 12 设备
 * 注意:该功能可通过以下方式扩展：例如，检查是否有任何
 * 输出设备（即显示器）已连接，枚举支持的分辨率，提供
 * 一种机制供用户在多适配器环境中选择要使用的适配器等
 * @return IDXGIAdapter4* 指向确定的 GPU 的智能指针
 */
IDXGIAdapter4*
determine_main_adapter()
{
	IDXGIAdapter4* adapter;
	for (u32 i{ 0 };
		dxgi_factory->EnumAdapterByGpuPreference(i, DXGI_GPU_PREFERENCE_HIGH_PERFORMANCE, IID_PPV_ARGS(&adapter)) != DXGI_ERROR_NOT_FOUND;
		++i)
	{
		//获取支持最小特征级别的 Direct3D 12 设备
		if (SUCCEEDED(D3D12CreateDevice(adapter, minumum_feature_level, __uuidof(ID3D12Device8), nullptr)))
		{
			return adapter;
		}
		release(adapter);
	}

	return nullptr;
}

/**
 * @brief 获取指定适配器支持的最高 Direct3D 特性级别
 * @details 检查指定适配器是否支持 Direct3D 12 特性级别
 * @param adapter 指向要检查的适配器的智能指针
 * @return D3D_FEATURE_LEVEL 支持的最高 Direct3D 特性级别
 */
D3D_FEATURE_LEVEL
get_max_feature_level(IDXGIAdapter4* adapter)
{
	constexpr D3D_FEATURE_LEVEL feature_levels[4]{
		D3D_FEATURE_LEVEL_11_0,
		D3D_FEATURE_LEVEL_11_1,
		D3D_FEATURE_LEVEL_12_0,
		D3D_FEATURE_LEVEL_12_1,
	};

	D3D12_FEATURE_DATA_FEATURE_LEVELS feature_level_info{};
	feature_level_info.NumFeatureLevels = (_countof(feature_levels));
	feature_level_info.pFeatureLevelsRequested = feature_levels;

	ComPtr<ID3D12Device> device;
	DXCall(D3D12CreateDevice(adapter, minumum_feature_level, IID_PPV_ARGS(&device)));
	DXCall(device->CheckFeatureSupport(D3D12_FEATURE_FEATURE_LEVELS, &feature_level_info, sizeof(feature_level_info)));

	return feature_level_info.MaxSupportedFeatureLevel;
}

}// anonymous namespace


bool
initialize()
{
	if (main_device) shutdown();


	// 在DEBUG模式下,捕获 DXGI 可能抛出的异常
	u32 dxgi_factory_flag{ 0 };
	// 开启调试层, 需要graphics tools支持
#ifdef _DEBUG
	{
		ComPtr<ID3D12Debug3> debug_interface;
		DXCall(D3D12GetDebugInterface(IID_PPV_ARGS(&debug_interface)));
		debug_interface->EnableDebugLayer();
		dxgi_factory_flag |= DXGI_CREATE_FACTORY_DEBUG;
	}
#endif

	// 创建 DXGI 工厂实例，用于枚举显卡适配器和创建交换链等操作
	HRESULT hr{ S_OK };
	DXCall(hr = CreateDXGIFactory2(dxgi_factory_flag, IID_PPV_ARGS(&dxgi_factory)));
	if (FAILED(hr)) return failed_init();

	// 确定要使用的 GPU
	ComPtr<IDXGIAdapter4> main_adapter;
	main_adapter.Attach(determine_main_adapter());
	if (!main_adapter) return failed_init();

	// 获取主适配器支持的最高 Direct3D 特性级别,并且不得低于最小要求
	D3D_FEATURE_LEVEL max_feature_level{ get_max_feature_level(main_adapter.Get()) };
	assert(max_feature_level >= minumum_feature_level);
	if (max_feature_level < minumum_feature_level) return failed_init();

	// 使用最高适配特性级别创建Direct3D 12 设备
	DXCall(hr = D3D12CreateDevice(main_adapter.Get(), max_feature_level, IID_PPV_ARGS(&main_device)));
	if (FAILED(hr)) return failed_init();

	// 为 Direct3D 12 设备设置名称
	NAME_D3D12_OBJECT(main_device, L"Main Device");

#ifdef _DEBUG
	{
		ComPtr<ID3D12InfoQueue> info_queue;
		DXCall(main_device->QueryInterface(IID_PPV_ARGS(&info_queue)));

		info_queue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_CORRUPTION, true);
		info_queue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_WARNING, true);
		info_queue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_ERROR, true);
	}
#endif // _DEBUG

	return true;
}
void
shutdown()
{
	release(dxgi_factory);

    // 关闭调试层,确保最后只有一个活动的主设备
#ifdef _DEBUG
	{
		{
			ComPtr<ID3D12InfoQueue> info_queue;
			DXCall(main_device->QueryInterface(IID_PPV_ARGS(&info_queue)));

			info_queue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_CORRUPTION, false);
			info_queue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_WARNING, false);
			info_queue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_ERROR, false);
		}

		ComPtr<ID3D12DebugDevice2> debug_device;
		DXCall(main_device->QueryInterface(IID_PPV_ARGS(&debug_device)));
		release(main_device);
		DXCall(debug_device->ReportLiveDeviceObjects(
			D3D12_RLDO_SUMMARY | D3D12_RLDO_DETAIL | D3D12_RLDO_IGNORE_INTERNAL
		));
	}
#endif // _DEBUG


	release(main_device);
}
}// namespace XEngine::graphics::d3d12::core