// Copyright 2017 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include <algorithm>
#include <cstddef>

#include "Common/Assert.h"
#include "Common/CommonTypes.h"
#include "Common/Logging/Log.h"

#include "VideoBackends/D3D/D3DState.h"
#include "VideoBackends/D3D/DXTexture.h"
#include "VideoBackends/D3DCommon/Common.h"
#include "VideoCommon/VideoConfig.h"

namespace DX11
{
DXTexture::DXTexture(const TextureConfig& config, ComPtr<ID3D11Texture2D> texture)
    : AbstractTexture(config), m_texture(std::move(texture))
{
}

DXTexture::~DXTexture()
{
  if (m_srv && D3D::stateman->UnsetTexture(m_srv.Get()) != 0)
    D3D::stateman->ApplyTextures();
}

std::unique_ptr<DXTexture> DXTexture::Create(const TextureConfig& config)
{
  // Use typeless to create the texture when it's a render target, so we can alias it with an
  // integer format (for EFB).
  const DXGI_FORMAT tex_format =
      D3DCommon::GetDXGIFormatForAbstractFormat(config.format, config.IsRenderTarget());
  UINT bindflags = D3D11_BIND_SHADER_RESOURCE;
  if (config.IsRenderTarget())
    bindflags |= IsDepthFormat(config.format) ? D3D11_BIND_DEPTH_STENCIL : D3D11_BIND_RENDER_TARGET;
  if (config.IsComputeImage())
    bindflags |= D3D11_BIND_UNORDERED_ACCESS;

  CD3D11_TEXTURE2D_DESC desc(tex_format, config.width, config.height, config.layers, config.levels,
                             bindflags, D3D11_USAGE_DEFAULT, 0, config.samples, 0, 0);
  ComPtr<ID3D11Texture2D> d3d_texture;
  HRESULT hr = D3D::device->CreateTexture2D(&desc, nullptr, d3d_texture.GetAddressOf());
  if (FAILED(hr))
  {
    PanicAlertFmt("Failed to create {}x{}x{} D3D backing texture", config.width, config.height,
                  config.layers);
    return nullptr;
  }

  std::unique_ptr<DXTexture> tex(new DXTexture(config, std::move(d3d_texture)));
  if (!tex->CreateSRV() || (config.IsComputeImage() && !tex->CreateUAV()))
    return nullptr;

  return tex;
}

std::unique_ptr<DXTexture> DXTexture::CreateAdopted(ComPtr<ID3D11Texture2D> texture)
{
  D3D11_TEXTURE2D_DESC desc;
  texture->GetDesc(&desc);

  // Convert to our texture config format.
  TextureConfig config(desc.Width, desc.Height, desc.MipLevels, desc.ArraySize,
                       desc.SampleDesc.Count,
                       D3DCommon::GetAbstractFormatForDXGIFormat(desc.Format), 0);
  if (desc.BindFlags & D3D11_BIND_RENDER_TARGET)
    config.flags |= AbstractTextureFlag_RenderTarget;
  if (desc.BindFlags & D3D11_BIND_UNORDERED_ACCESS)
    config.flags |= AbstractTextureFlag_ComputeImage;

  std::unique_ptr<DXTexture> tex(new DXTexture(config, std::move(texture)));
  if (desc.BindFlags & D3D11_BIND_SHADER_RESOURCE && !tex->CreateSRV())
    return nullptr;
  if (desc.BindFlags & D3D11_BIND_UNORDERED_ACCESS && !tex->CreateUAV())
    return nullptr;

  return tex;
}

bool DXTexture::CreateSRV()
{
  const CD3D11_SHADER_RESOURCE_VIEW_DESC desc(
      m_texture.Get(),
      m_config.IsMultisampled() ? D3D11_SRV_DIMENSION_TEXTURE2DMSARRAY :
                                  D3D11_SRV_DIMENSION_TEXTURE2DARRAY,
      D3DCommon::GetSRVFormatForAbstractFormat(m_config.format), 0, m_config.levels, 0,
      m_config.layers);
  DEBUG_ASSERT(!m_srv);
  HRESULT hr = D3D::device->CreateShaderResourceView(m_texture.Get(), &desc, m_srv.GetAddressOf());
  if (FAILED(hr))
  {
    PanicAlertFmt("Failed to create {}x{}x{} D3D SRV", m_config.width, m_config.height,
                  m_config.layers);
    return false;
  }

  return true;
}

bool DXTexture::CreateUAV()
{
  const CD3D11_UNORDERED_ACCESS_VIEW_DESC desc(
      m_texture.Get(), D3D11_UAV_DIMENSION_TEXTURE2DARRAY,
      D3DCommon::GetSRVFormatForAbstractFormat(m_config.format), 0, 0, m_config.layers);
  DEBUG_ASSERT(!m_uav);
  HRESULT hr = D3D::device->CreateUnorderedAccessView(m_texture.Get(), &desc, m_uav.GetAddressOf());
  if (FAILED(hr))
  {
    PanicAlertFmt("Failed to create {}x{}x{} D3D UAV", m_config.width, m_config.height,
                  m_config.layers);
    return false;
  }

  return true;
}

void DXTexture::CopyRectangleFromTexture(const AbstractTexture* src,
                                         const MathUtil::Rectangle<int>& src_rect, u32 src_layer,
                                         u32 src_level, const MathUtil::Rectangle<int>& dst_rect,
                                         u32 dst_layer, u32 dst_level)
{
  const DXTexture* srcentry = static_cast<const DXTexture*>(src);
  ASSERT(src_rect.GetWidth() == dst_rect.GetWidth() &&
         src_rect.GetHeight() == dst_rect.GetHeight());

  D3D11_BOX src_box;
  src_box.left = src_rect.left;
  src_box.top = src_rect.top;
  src_box.right = src_rect.right;
  src_box.bottom = src_rect.bottom;
  src_box.front = 0;
  src_box.back = 1;

  D3D::context->CopySubresourceRegion(
      m_texture.Get(), D3D11CalcSubresource(dst_level, dst_layer, m_config.levels), dst_rect.left,
      dst_rect.top, 0, srcentry->m_texture.Get(),
      D3D11CalcSubresource(src_level, src_layer, srcentry->m_config.levels), &src_box);
}

void DXTexture::ResolveFromTexture(const AbstractTexture* src, const MathUtil::Rectangle<int>& rect,
                                   u32 layer, u32 level)
{
  const DXTexture* srcentry = static_cast<const DXTexture*>(src);
  DEBUG_ASSERT(m_config.samples > 1 && m_config.width == srcentry->m_config.width &&
               m_config.height == srcentry->m_config.height && m_config.samples == 1);
  DEBUG_ASSERT(rect.left + rect.GetWidth() <= static_cast<int>(srcentry->m_config.width) &&
               rect.top + rect.GetHeight() <= static_cast<int>(srcentry->m_config.height));

  D3D::context->ResolveSubresource(
      m_texture.Get(), D3D11CalcSubresource(level, layer, m_config.levels),
      srcentry->m_texture.Get(), D3D11CalcSubresource(level, layer, srcentry->m_config.levels),
      D3DCommon::GetDXGIFormatForAbstractFormat(m_config.format, false));
}

void DXTexture::Load(u32 level, u32 width, u32 height, u32 row_length, const u8* buffer,
                     size_t buffer_size)
{
  size_t src_pitch = CalculateStrideForFormat(m_config.format, row_length);
  D3D::context->UpdateSubresource(m_texture.Get(), level, nullptr, buffer,
                                  static_cast<UINT>(src_pitch), 0);
}

DXStagingTexture::DXStagingTexture(StagingTextureType type, const TextureConfig& config,
                                   ComPtr<ID3D11Texture2D> tex)
    : AbstractStagingTexture(type, config), m_tex(std::move(tex))
{
}

DXStagingTexture::~DXStagingTexture()
{
  if (IsMapped())
    DXStagingTexture::Unmap();
}

std::unique_ptr<DXStagingTexture> DXStagingTexture::Create(StagingTextureType type,
                                                           const TextureConfig& config)
{
  D3D11_USAGE usage;
  UINT cpu_flags;
  if (type == StagingTextureType::Readback)
  {
    usage = D3D11_USAGE_STAGING;
    cpu_flags = D3D11_CPU_ACCESS_READ;
  }
  else if (type == StagingTextureType::Upload)
  {
    usage = D3D11_USAGE_DYNAMIC;
    cpu_flags = D3D11_CPU_ACCESS_WRITE;
  }
  else
  {
    usage = D3D11_USAGE_STAGING;
    cpu_flags = D3D11_CPU_ACCESS_READ | D3D11_CPU_ACCESS_WRITE;
  }

  CD3D11_TEXTURE2D_DESC desc(D3DCommon::GetDXGIFormatForAbstractFormat(config.format, false),
                             config.width, config.height, 1, 1, 0, usage, cpu_flags);

  ComPtr<ID3D11Texture2D> texture;
  HRESULT hr = D3D::device->CreateTexture2D(&desc, nullptr, texture.GetAddressOf());
  CHECK(SUCCEEDED(hr), "Create staging texture");
  if (FAILED(hr))
    return nullptr;

  return std::unique_ptr<DXStagingTexture>(new DXStagingTexture(type, config, std::move(texture)));
}

void DXStagingTexture::CopyFromTexture(const AbstractTexture* src,
                                       const MathUtil::Rectangle<int>& src_rect, u32 src_layer,
                                       u32 src_level, const MathUtil::Rectangle<int>& dst_rect)
{
  ASSERT(m_type == StagingTextureType::Readback || m_type == StagingTextureType::Mutable);
  ASSERT(src_rect.GetWidth() == dst_rect.GetWidth() &&
         src_rect.GetHeight() == dst_rect.GetHeight());
  ASSERT(src_rect.left >= 0 && static_cast<u32>(src_rect.right) <= src->GetWidth() &&
         src_rect.top >= 0 && static_cast<u32>(src_rect.bottom) <= src->GetHeight());
  ASSERT(dst_rect.left >= 0 && static_cast<u32>(dst_rect.right) <= m_config.width &&
         dst_rect.top >= 0 && static_cast<u32>(dst_rect.bottom) <= m_config.height);

  if (IsMapped())
    DXStagingTexture::Unmap();

  if (static_cast<u32>(src_rect.GetWidth()) == GetWidth() &&
      static_cast<u32>(src_rect.GetHeight()) == GetHeight())
  {
    // Copy whole resource, needed for depth textures.
    D3D::context->CopySubresourceRegion(
        m_tex.Get(), 0, 0, 0, 0, static_cast<const DXTexture*>(src)->GetD3DTexture(),
        D3D11CalcSubresource(src_level, src_layer, src->GetLevels()), nullptr);
  }
  else
  {
    CD3D11_BOX src_box(src_rect.left, src_rect.top, 0, src_rect.right, src_rect.bottom, 1);
    D3D::context->CopySubresourceRegion(
        m_tex.Get(), 0, static_cast<u32>(dst_rect.left), static_cast<u32>(dst_rect.top), 0,
        static_cast<const DXTexture*>(src)->GetD3DTexture(),
        D3D11CalcSubresource(src_level, src_layer, src->GetLevels()), &src_box);
  }

  m_needs_flush = true;
}

void DXStagingTexture::CopyToTexture(const MathUtil::Rectangle<int>& src_rect, AbstractTexture* dst,
                                     const MathUtil::Rectangle<int>& dst_rect, u32 dst_layer,
                                     u32 dst_level)
{
  ASSERT(m_type == StagingTextureType::Upload);
  ASSERT(src_rect.GetWidth() == dst_rect.GetWidth() &&
         src_rect.GetHeight() == dst_rect.GetHeight());
  ASSERT(src_rect.left >= 0 && static_cast<u32>(src_rect.right) <= GetWidth() &&
         src_rect.top >= 0 && static_cast<u32>(src_rect.bottom) <= GetHeight());
  ASSERT(dst_rect.left >= 0 && static_cast<u32>(dst_rect.right) <= dst->GetWidth() &&
         dst_rect.top >= 0 && static_cast<u32>(dst_rect.bottom) <= dst->GetHeight());

  if (IsMapped())
    DXStagingTexture::Unmap();

  if (static_cast<u32>(src_rect.GetWidth()) == dst->GetWidth() &&
      static_cast<u32>(src_rect.GetHeight()) == dst->GetHeight())
  {
    D3D::context->CopySubresourceRegion(
        static_cast<const DXTexture*>(dst)->GetD3DTexture(),
        D3D11CalcSubresource(dst_level, dst_layer, dst->GetLevels()), 0, 0, 0, m_tex.Get(), 0,
        nullptr);
  }
  else
  {
    CD3D11_BOX src_box(src_rect.left, src_rect.top, 0, src_rect.right, src_rect.bottom, 1);
    D3D::context->CopySubresourceRegion(
        static_cast<const DXTexture*>(dst)->GetD3DTexture(),
        D3D11CalcSubresource(dst_level, dst_layer, dst->GetLevels()),
        static_cast<u32>(dst_rect.left), static_cast<u32>(dst_rect.top), 0, m_tex.Get(), 0,
        &src_box);
  }
}

bool DXStagingTexture::Map()
{
  if (m_map_pointer)
    return true;

  D3D11_MAP map_type;
  if (m_type == StagingTextureType::Readback)
    map_type = D3D11_MAP_READ;
  else if (m_type == StagingTextureType::Upload)
    map_type = D3D11_MAP_WRITE;
  else
    map_type = D3D11_MAP_READ_WRITE;

  D3D11_MAPPED_SUBRESOURCE sr;
  HRESULT hr = D3D::context->Map(m_tex.Get(), 0, map_type, 0, &sr);
  CHECK(SUCCEEDED(hr), "Map readback texture");
  if (FAILED(hr))
    return false;

  m_map_pointer = reinterpret_cast<char*>(sr.pData);
  m_map_stride = sr.RowPitch;
  return true;
}

void DXStagingTexture::Unmap()
{
  if (!m_map_pointer)
    return;

  D3D::context->Unmap(m_tex.Get(), 0);
  m_map_pointer = nullptr;
}

void DXStagingTexture::Flush()
{
  // Flushing is handled by the API.
  m_needs_flush = false;
}

DXFramebuffer::DXFramebuffer(AbstractTexture* color_attachment, AbstractTexture* depth_attachment,
                             AbstractTextureFormat color_format, AbstractTextureFormat depth_format,
                             u32 width, u32 height, u32 layers, u32 samples,
                             ComPtr<ID3D11RenderTargetView> rtv,
                             ComPtr<ID3D11RenderTargetView> integer_rtv,
                             ComPtr<ID3D11DepthStencilView> dsv)
    : AbstractFramebuffer(color_attachment, depth_attachment, color_format, depth_format, width,
                          height, layers, samples),
      m_rtv(std::move(rtv)), m_integer_rtv(std::move(integer_rtv)), m_dsv(std::move(dsv))
{
}

DXFramebuffer::~DXFramebuffer() = default;

std::unique_ptr<DXFramebuffer> DXFramebuffer::Create(DXTexture* color_attachment,
                                                     DXTexture* depth_attachment)
{
  if (!ValidateConfig(color_attachment, depth_attachment))
    return nullptr;

  const AbstractTextureFormat color_format =
      color_attachment ? color_attachment->GetFormat() : AbstractTextureFormat::Undefined;
  const AbstractTextureFormat depth_format =
      depth_attachment ? depth_attachment->GetFormat() : AbstractTextureFormat::Undefined;
  const DXTexture* either_attachment = color_attachment ? color_attachment : depth_attachment;
  const u32 width = either_attachment->GetWidth();
  const u32 height = either_attachment->GetHeight();
  const u32 layers = either_attachment->GetLayers();
  const u32 samples = either_attachment->GetSamples();

  ComPtr<ID3D11RenderTargetView> rtv;
  ComPtr<ID3D11RenderTargetView> integer_rtv;
  if (color_attachment)
  {
    CD3D11_RENDER_TARGET_VIEW_DESC desc(
        color_attachment->IsMultisampled() ? D3D11_RTV_DIMENSION_TEXTURE2DMSARRAY :
                                             D3D11_RTV_DIMENSION_TEXTURE2DARRAY,
        D3DCommon::GetRTVFormatForAbstractFormat(color_attachment->GetFormat(), false), 0, 0,
        color_attachment->GetLayers());
    HRESULT hr = D3D::device->CreateRenderTargetView(color_attachment->GetD3DTexture(), &desc,
                                                     rtv.GetAddressOf());
    CHECK(SUCCEEDED(hr), "Create render target view for framebuffer");
    if (FAILED(hr))
      return nullptr;

    // Only create the integer RTV when logic ops are supported (Win8+).
    DXGI_FORMAT integer_format =
        D3DCommon::GetRTVFormatForAbstractFormat(color_attachment->GetFormat(), true);
    if (g_ActiveConfig.backend_info.bSupportsLogicOp && integer_format != desc.Format)
    {
      desc.Format = integer_format;
      hr = D3D::device->CreateRenderTargetView(color_attachment->GetD3DTexture(), &desc,
                                               integer_rtv.GetAddressOf());
      CHECK(SUCCEEDED(hr), "Create integer render target view for framebuffer");
    }
  }

  ComPtr<ID3D11DepthStencilView> dsv;
  if (depth_attachment)
  {
    const CD3D11_DEPTH_STENCIL_VIEW_DESC desc(
        depth_attachment->GetConfig().IsMultisampled() ? D3D11_DSV_DIMENSION_TEXTURE2DMSARRAY :
                                                         D3D11_DSV_DIMENSION_TEXTURE2DARRAY,
        D3DCommon::GetDSVFormatForAbstractFormat(depth_attachment->GetFormat()), 0, 0,
        depth_attachment->GetLayers(), 0);
    HRESULT hr = D3D::device->CreateDepthStencilView(depth_attachment->GetD3DTexture(), &desc,
                                                     dsv.GetAddressOf());
    CHECK(SUCCEEDED(hr), "Create depth stencil view for framebuffer");
    if (FAILED(hr))
      return nullptr;
  }

  return std::make_unique<DXFramebuffer>(color_attachment, depth_attachment, color_format,
                                         depth_format, width, height, layers, samples,
                                         std::move(rtv), std::move(integer_rtv), std::move(dsv));
}

}  // namespace DX11