// Copyright 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "stdafx.h"
#include <corewindow.h>
#include <windows.applicationmodel.core.h>
#include <windows.graphics.display.h>

#include "win8/metro_driver/direct3d_helper.h"
#include "base/logging.h"
#include "base/win/windows_version.h"
#include "ui/gfx/win/dpi.h"
#include "win8/metro_driver/winrt_utils.h"

namespace {

void CheckIfFailed(HRESULT hr) {
  DCHECK(!FAILED(hr));
  if (FAILED(hr))
    DVLOG(0) << "Direct3D call failed, hr = " << hr;
}

float ConvertDipsToPixels(float dips) {
  return floor(dips * gfx::GetDPIScale() + 0.5f);
}

}

namespace metro_driver {

Direct3DHelper::Direct3DHelper() {
}

Direct3DHelper::~Direct3DHelper() {
}

void Direct3DHelper::Initialize(winui::Core::ICoreWindow* window) {
  window_ = window;
  CreateDeviceResources();
  CreateWindowSizeDependentResources();
}

// TODO(scottmg): Need to handle resize messages and recreation.

void Direct3DHelper::CreateDeviceResources() {
  unsigned int creation_flags = D3D11_CREATE_DEVICE_BGRA_SUPPORT;
  D3D_FEATURE_LEVEL feature_levels[] = {
    D3D_FEATURE_LEVEL_11_1,
    D3D_FEATURE_LEVEL_11_0,
    D3D_FEATURE_LEVEL_10_1,
    D3D_FEATURE_LEVEL_10_0,
    D3D_FEATURE_LEVEL_9_3,
    D3D_FEATURE_LEVEL_9_2,
    D3D_FEATURE_LEVEL_9_1,
  };

  mswr::ComPtr<ID3D11Device> device;
  mswr::ComPtr<ID3D11DeviceContext> context;
  CheckIfFailed(
      D3D11CreateDevice(
          nullptr,
          D3D_DRIVER_TYPE_HARDWARE,
          nullptr,
          creation_flags,
          feature_levels,
          ARRAYSIZE(feature_levels),
          D3D11_SDK_VERSION,
          &device,
          &feature_level_,
          &context));
  CheckIfFailed(device.As(&d3d_device_));
  CheckIfFailed(context.As(&d3d_context_));
}

void Direct3DHelper::CreateWindowSizeDependentResources() {
  float window_width = 0;
  float window_height = 0;

  if (base::win::GetVersion() >= base::win::VERSION_WIN8) {
    // Windows 8 returns in DIPs.
    CheckIfFailed(window_->get_Bounds(&window_bounds_));
    window_width = ConvertDipsToPixels(window_width);
    window_height = ConvertDipsToPixels(window_height);
  }

  // TODO(scottmg): Orientation.

  if (swap_chain_ != nullptr) {
    // TODO(scottmg): Resize if it already exists.
    NOTIMPLEMENTED();
  } else {
    DXGI_SWAP_CHAIN_DESC1 swap_chain_desc = { 0 };
    swap_chain_desc.Width = window_width;
    swap_chain_desc.Height = window_height;
    swap_chain_desc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
    swap_chain_desc.Stereo = false;
    swap_chain_desc.SampleDesc.Count = 1;
    swap_chain_desc.SampleDesc.Quality = 0;
    swap_chain_desc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
    swap_chain_desc.BufferCount = 2; // TODO(scottmg): Probably 1 is fine.
    swap_chain_desc.Scaling = DXGI_SCALING_NONE;
    swap_chain_desc.SwapEffect = DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL;
    swap_chain_desc.Flags = 0;

    mswr::ComPtr<IDXGIDevice1> dxgi_device;
    CheckIfFailed(d3d_device_.As(&dxgi_device));

    mswr::ComPtr<IDXGIAdapter> dxgi_adapter;
    CheckIfFailed(dxgi_device->GetAdapter(&dxgi_adapter));

    mswr::ComPtr<IDXGIFactory2> dxgi_factory;
    CheckIfFailed(dxgi_adapter->GetParent(
        __uuidof(IDXGIFactory2), &dxgi_factory));

    if (base::win::GetVersion() >= base::win::VERSION_WIN8) {
      // On Win8 we need the CoreWindow interface to create the Swapchain.
      CheckIfFailed(dxgi_factory->CreateSwapChainForCoreWindow(
          d3d_device_.Get(),
          reinterpret_cast<IUnknown*>(window_),
          &swap_chain_desc,
          nullptr,
          &swap_chain_));
    } else {
      // On Win7 we need the raw HWND to create the Swapchain.
      mswr::ComPtr<ICoreWindowInterop> interop;
      CheckIfFailed(window_->QueryInterface(interop.GetAddressOf()));
      HWND window = NULL;
      interop->get_WindowHandle(&window);

      swap_chain_desc.Scaling = DXGI_SCALING_STRETCH;
      swap_chain_desc.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;

      CheckIfFailed(dxgi_factory->CreateSwapChainForHwnd(
          d3d_device_.Get(),
          window,
          &swap_chain_desc,
          nullptr,
          nullptr,
          &swap_chain_));
      // Prevent DXGI from monitoring an application message queue and thus
      // attempt mode changes. For e.g. Alt + Enter by default causes
      // DXGI to attempt to take the window fullscreen.
      CheckIfFailed(dxgi_factory->MakeWindowAssociation(
          window, DXGI_MWA_NO_WINDOW_CHANGES));
    }
  }
}

}  // namespace metro_driver