// Copyright 2010 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include <algorithm>

#include "Common/CommonTypes.h"
#include "Common/DynamicLibrary.h"
#include "Common/Logging/Log.h"
#include "Common/MsgHandler.h"
#include "Common/StringUtil.h"
#include "Core/Config/GraphicsSettings.h"
#include "Core/ConfigManager.h"
#include "VideoBackends/D3D/D3DBase.h"
#include "VideoBackends/D3D/D3DState.h"
#include "VideoBackends/D3D/DXTexture.h"
#include "VideoBackends/D3DCommon/Common.h"
#include "VideoCommon/VideoConfig.h"

namespace DX11
{
static Common::DynamicLibrary s_d3d11_library;
namespace D3D
{
ComPtr<IDXGIFactory2> dxgi_factory;
ComPtr<ID3D11Device> device;
ComPtr<ID3D11Device1> device1;
ComPtr<ID3D11DeviceContext> context;
D3D_FEATURE_LEVEL feature_level;

static ComPtr<ID3D11Debug> s_debug;

static constexpr D3D_FEATURE_LEVEL s_supported_feature_levels[] = {
    D3D_FEATURE_LEVEL_11_0, D3D_FEATURE_LEVEL_10_1, D3D_FEATURE_LEVEL_10_0};

static bool SupportsS3TCTextures()
{
  UINT bc1_support, bc2_support, bc3_support;
  if (FAILED(device->CheckFormatSupport(DXGI_FORMAT_BC1_UNORM, &bc1_support)) ||
      FAILED(device->CheckFormatSupport(DXGI_FORMAT_BC2_UNORM, &bc2_support)) ||
      FAILED(device->CheckFormatSupport(DXGI_FORMAT_BC3_UNORM, &bc3_support)))
  {
    return false;
  }

  return ((bc1_support & bc2_support & bc3_support) & D3D11_FORMAT_SUPPORT_TEXTURE2D) != 0;
}

static bool SupportsBPTCTextures()
{
  // Currently, we only care about BC7. This could be extended to BC6H in the future.
  UINT bc7_support;
  if (FAILED(device->CheckFormatSupport(DXGI_FORMAT_BC7_UNORM, &bc7_support)))
    return false;

  return (bc7_support & D3D11_FORMAT_SUPPORT_TEXTURE2D) != 0;
}

bool Create(u32 adapter_index, bool enable_debug_layer)
{
  PFN_D3D11_CREATE_DEVICE d3d11_create_device;
  if (!s_d3d11_library.Open("d3d11.dll") ||
      !s_d3d11_library.GetSymbol("D3D11CreateDevice", &d3d11_create_device))
  {
    PanicAlertT("Failed to load d3d11.dll");
    s_d3d11_library.Close();
    return false;
  }

  if (!D3DCommon::LoadLibraries())
  {
    s_d3d11_library.Close();
    return false;
  }

  dxgi_factory = D3DCommon::CreateDXGIFactory(enable_debug_layer);
  if (!dxgi_factory)
  {
    PanicAlertT("Failed to create DXGI factory");
    D3DCommon::UnloadLibraries();
    s_d3d11_library.Close();
    return false;
  }

  ComPtr<IDXGIAdapter> adapter;
  HRESULT hr = dxgi_factory->EnumAdapters(adapter_index, &adapter);
  if (FAILED(hr))
  {
    WARN_LOG(VIDEO, "Adapter %u not found, using default", adapter_index);
    adapter = nullptr;
  }

  // Creating debug devices can sometimes fail if the user doesn't have the correct
  // version of the DirectX SDK. If it does, simply fallback to a non-debug device.
  if (enable_debug_layer)
  {
    hr = d3d11_create_device(adapter.Get(), D3D_DRIVER_TYPE_UNKNOWN, nullptr,
                             D3D11_CREATE_DEVICE_DEBUG, s_supported_feature_levels,
                             static_cast<UINT>(ArraySize(s_supported_feature_levels)),
                             D3D11_SDK_VERSION, &device, &feature_level, &context);

    // Debugbreak on D3D error
    if (SUCCEEDED(hr) && SUCCEEDED(device->QueryInterface(IID_PPV_ARGS(&s_debug))))
    {
      ComPtr<ID3D11InfoQueue> info_queue;
      if (SUCCEEDED(s_debug->QueryInterface(IID_PPV_ARGS(&info_queue))))
      {
        info_queue->SetBreakOnSeverity(D3D11_MESSAGE_SEVERITY_CORRUPTION, true);
        info_queue->SetBreakOnSeverity(D3D11_MESSAGE_SEVERITY_ERROR, true);

        D3D11_MESSAGE_ID hide[] = {D3D11_MESSAGE_ID_SETPRIVATEDATA_CHANGINGPARAMS};

        D3D11_INFO_QUEUE_FILTER filter = {};
        filter.DenyList.NumIDs = sizeof(hide) / sizeof(D3D11_MESSAGE_ID);
        filter.DenyList.pIDList = hide;
        info_queue->AddStorageFilterEntries(&filter);
      }
    }
    else
    {
      WARN_LOG(VIDEO, "Debug layer requested but not available.");
    }
  }

  if (!enable_debug_layer || FAILED(hr))
  {
    hr = d3d11_create_device(adapter.Get(), D3D_DRIVER_TYPE_UNKNOWN, nullptr, 0,
                             s_supported_feature_levels,
                             static_cast<UINT>(ArraySize(s_supported_feature_levels)),
                             D3D11_SDK_VERSION, &device, &feature_level, &context);
  }

  if (FAILED(hr))
  {
    PanicAlertT(
        "Failed to initialize Direct3D.\nMake sure your video card supports at least D3D 10.0");
    D3DCommon::UnloadLibraries();
    return false;
  }

  hr = device->QueryInterface(IID_PPV_ARGS(&device1));
  if (FAILED(hr))
  {
    WARN_LOG(VIDEO, "Missing Direct3D 11.1 support. Logical operations will not be supported.");
    g_Config.backend_info.bSupportsLogicOp = false;
  }

  g_Config.backend_info.bSupportsST3CTextures = SupportsS3TCTextures();
  g_Config.backend_info.bSupportsBPTCTextures = SupportsBPTCTextures();

  // Features only supported with a FL11.0+ device.
  const bool shader_model_5_supported = feature_level >= D3D_FEATURE_LEVEL_11_0;
  g_Config.backend_info.bSupportsEarlyZ = shader_model_5_supported;
  g_Config.backend_info.bSupportsBBox = shader_model_5_supported;
  g_Config.backend_info.bSupportsFragmentStoresAndAtomics = shader_model_5_supported;
  g_Config.backend_info.bSupportsGSInstancing = shader_model_5_supported;
  g_Config.backend_info.bSupportsSSAA = shader_model_5_supported;

  stateman = std::make_unique<StateManager>();
  return true;
}

void Destroy()
{
  stateman.reset();

  context->ClearState();
  context->Flush();

  context.Reset();
  device1.Reset();

  auto remaining_references = device.Reset();
  if (s_debug)
  {
    --remaining_references;  // the debug interface increases the refcount of the device, subtract
                             // that.
    if (remaining_references)
    {
      // print out alive objects, but only if we actually have pending references
      // note this will also print out internal live objects to the debug console
      s_debug->ReportLiveDeviceObjects(D3D11_RLDO_SUMMARY | D3D11_RLDO_DETAIL);
    }
    s_debug.Reset();
  }

  if (remaining_references)
    ERROR_LOG(VIDEO, "Unreleased references: %i.", remaining_references);
  else
    NOTICE_LOG(VIDEO, "Successfully released all device references!");

  D3DCommon::UnloadLibraries();
  s_d3d11_library.Close();
}

std::vector<u32> GetAAModes(u32 adapter_index)
{
  // Use temporary device if we don't have one already.
  Common::DynamicLibrary temp_lib;
  ComPtr<ID3D11Device> temp_device = device;
  if (!temp_device)
  {
    ComPtr<IDXGIFactory2> temp_dxgi_factory = D3DCommon::CreateDXGIFactory(false);
    if (!temp_dxgi_factory)
      return {};

    ComPtr<IDXGIAdapter> adapter;
    temp_dxgi_factory->EnumAdapters(adapter_index, &adapter);

    PFN_D3D11_CREATE_DEVICE d3d11_create_device;
    if (!temp_lib.Open("d3d11.dll") ||
        !temp_lib.GetSymbol("D3D11CreateDevice", &d3d11_create_device))
    {
      return {};
    }

    HRESULT hr = d3d11_create_device(nullptr, D3D_DRIVER_TYPE_HARDWARE, nullptr, 0,
                                     s_supported_feature_levels,
                                     static_cast<UINT>(ArraySize(s_supported_feature_levels)),
                                     D3D11_SDK_VERSION, &temp_device, nullptr, nullptr);
    if (FAILED(hr))
      return {};
  }

  // NOTE: D3D 10.0 doesn't support multisampled resources which are bound as depth buffers AND
  // shader resources. Thus, we can't have MSAA with 10.0 level hardware.
  if (temp_device->GetFeatureLevel() == D3D_FEATURE_LEVEL_10_0)
    return {};

  std::vector<u32> aa_modes;
  for (u32 samples = 1; samples < D3D11_MAX_MULTISAMPLE_SAMPLE_COUNT; ++samples)
  {
    UINT quality_levels = 0;
    if (SUCCEEDED(temp_device->CheckMultisampleQualityLevels(DXGI_FORMAT_R8G8B8A8_UNORM, samples,
                                                             &quality_levels)) &&
        quality_levels > 0)
    {
      aa_modes.push_back(samples);
    }
  }

  return aa_modes;
}
}  // namespace D3D

}  // namespace DX11