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

#include <algorithm>
#include <memory>

#include "VideoBackends/D3D/D3DBase.h"
#include "VideoBackends/D3D/D3DShader.h"
#include "VideoBackends/D3D/D3DState.h"
#include "VideoBackends/D3D/D3DUtil.h"
#include "VideoBackends/D3D/FramebufferManager.h"
#include "VideoBackends/D3D/GeometryShaderCache.h"
#include "VideoBackends/D3D/PSTextureEncoder.h"
#include "VideoBackends/D3D/PixelShaderCache.h"
#include "VideoBackends/D3D/TextureCache.h"
#include "VideoBackends/D3D/TextureEncoder.h"
#include "VideoBackends/D3D/VertexShaderCache.h"
#include "VideoCommon/ImageWrite.h"
#include "VideoCommon/LookUpTables.h"
#include "VideoCommon/RenderBase.h"
#include "VideoCommon/VideoConfig.h"

namespace DX11
{
static std::unique_ptr<TextureEncoder> g_encoder;
const size_t MAX_COPY_BUFFERS = 32;
ID3D11Buffer* efbcopycbuf[MAX_COPY_BUFFERS] = {0};

TextureCache::TCacheEntry::~TCacheEntry()
{
  texture->Release();
}

void TextureCache::TCacheEntry::Bind(unsigned int stage)
{
  D3D::stateman->SetTexture(stage, texture->GetSRV());
}

bool TextureCache::TCacheEntry::Save(const std::string& filename, unsigned int level)
{
  // Create a staging/readback texture with the dimensions of the specified mip level.
  u32 mip_width = std::max(config.width >> level, 1u);
  u32 mip_height = std::max(config.height >> level, 1u);
  CD3D11_TEXTURE2D_DESC staging_texture_desc(DXGI_FORMAT_R8G8B8A8_UNORM, mip_width, mip_height, 1,
                                             1, 0, D3D11_USAGE_STAGING, D3D11_CPU_ACCESS_READ);

  ID3D11Texture2D* staging_texture;
  HRESULT hr = D3D::device->CreateTexture2D(&staging_texture_desc, nullptr, &staging_texture);
  if (FAILED(hr))
  {
    WARN_LOG(VIDEO, "Failed to create texture dumping readback texture: %X", static_cast<u32>(hr));
    return false;
  }

  // Copy the selected mip level to the staging texture.
  CD3D11_BOX src_box(0, 0, 0, mip_width, mip_height, 1);
  D3D::context->CopySubresourceRegion(staging_texture, 0, 0, 0, 0, texture->GetTex(),
                                      D3D11CalcSubresource(level, 0, config.levels), &src_box);

  // Map the staging texture to client memory, and encode it as a .png image.
  D3D11_MAPPED_SUBRESOURCE map;
  hr = D3D::context->Map(staging_texture, 0, D3D11_MAP_READ, 0, &map);
  if (FAILED(hr))
  {
    WARN_LOG(VIDEO, "Failed to map texture dumping readback texture: %X", static_cast<u32>(hr));
    staging_texture->Release();
    return false;
  }

  bool encode_result =
      TextureToPng(reinterpret_cast<u8*>(map.pData), map.RowPitch, filename, mip_width, mip_height);
  D3D::context->Unmap(staging_texture, 0);
  staging_texture->Release();

  return encode_result;
}

void TextureCache::TCacheEntry::CopyRectangleFromTexture(const TCacheEntryBase* source,
                                                         const MathUtil::Rectangle<int>& srcrect,
                                                         const MathUtil::Rectangle<int>& dstrect)
{
  TCacheEntry* srcentry = (TCacheEntry*)source;
  if (srcrect.GetWidth() == dstrect.GetWidth() && srcrect.GetHeight() == dstrect.GetHeight())
  {
    D3D11_BOX srcbox;
    srcbox.left = srcrect.left;
    srcbox.top = srcrect.top;
    srcbox.right = srcrect.right;
    srcbox.bottom = srcrect.bottom;
    srcbox.front = 0;
    srcbox.back = srcentry->config.layers;

    D3D::context->CopySubresourceRegion(texture->GetTex(), 0, dstrect.left, dstrect.top, 0,
                                        srcentry->texture->GetTex(), 0, &srcbox);
    return;
  }
  else if (!config.rendertarget)
  {
    return;
  }
  g_renderer->ResetAPIState();  // reset any game specific settings

  const D3D11_VIEWPORT vp = CD3D11_VIEWPORT(float(dstrect.left), float(dstrect.top),
                                            float(dstrect.GetWidth()), float(dstrect.GetHeight()));

  D3D::stateman->UnsetTexture(texture->GetSRV());
  D3D::stateman->Apply();

  D3D::context->OMSetRenderTargets(1, &texture->GetRTV(), nullptr);
  D3D::context->RSSetViewports(1, &vp);
  D3D::SetLinearCopySampler();
  D3D11_RECT srcRC;
  srcRC.left = srcrect.left;
  srcRC.right = srcrect.right;
  srcRC.top = srcrect.top;
  srcRC.bottom = srcrect.bottom;
  D3D::drawShadedTexQuad(srcentry->texture->GetSRV(), &srcRC, srcentry->config.width,
                         srcentry->config.height, PixelShaderCache::GetColorCopyProgram(false),
                         VertexShaderCache::GetSimpleVertexShader(),
                         VertexShaderCache::GetSimpleInputLayout(),
                         GeometryShaderCache::GetCopyGeometryShader(), 1.0, 0);

  D3D::context->OMSetRenderTargets(1, &FramebufferManager::GetEFBColorTexture()->GetRTV(),
                                   FramebufferManager::GetEFBDepthTexture()->GetDSV());

  g_renderer->RestoreAPIState();
}

void TextureCache::TCacheEntry::Load(const u8* buffer, u32 width, u32 height, u32 expanded_width,
                                     u32 level)
{
  unsigned int src_pitch = 4 * expanded_width;
  D3D::ReplaceRGBATexture2D(texture->GetTex(), buffer, width, height, src_pitch, level, usage);
}

TextureCacheBase::TCacheEntryBase* TextureCache::CreateTexture(const TCacheEntryConfig& config)
{
  if (config.rendertarget)
  {
    return new TCacheEntry(
        config, D3DTexture2D::Create(
                    config.width, config.height, (D3D11_BIND_FLAG)((int)D3D11_BIND_RENDER_TARGET |
                                                                   (int)D3D11_BIND_SHADER_RESOURCE),
                    D3D11_USAGE_DEFAULT, DXGI_FORMAT_R8G8B8A8_UNORM, 1, config.layers));
  }
  else
  {
    D3D11_USAGE usage = D3D11_USAGE_DEFAULT;
    D3D11_CPU_ACCESS_FLAG cpu_access = (D3D11_CPU_ACCESS_FLAG)0;

    if (config.levels == 1)
    {
      usage = D3D11_USAGE_DYNAMIC;
      cpu_access = D3D11_CPU_ACCESS_WRITE;
    }

    const D3D11_TEXTURE2D_DESC texdesc =
        CD3D11_TEXTURE2D_DESC(DXGI_FORMAT_R8G8B8A8_UNORM, config.width, config.height, 1,
                              config.levels, D3D11_BIND_SHADER_RESOURCE, usage, cpu_access);

    ID3D11Texture2D* pTexture;
    const HRESULT hr = D3D::device->CreateTexture2D(&texdesc, nullptr, &pTexture);
    CHECK(SUCCEEDED(hr), "Create texture of the TextureCache");

    TCacheEntry* const entry =
        new TCacheEntry(config, new D3DTexture2D(pTexture, D3D11_BIND_SHADER_RESOURCE));
    entry->usage = usage;

    // TODO: better debug names
    D3D::SetDebugObjectName((ID3D11DeviceChild*)entry->texture->GetTex(),
                            "a texture of the TextureCache");
    D3D::SetDebugObjectName((ID3D11DeviceChild*)entry->texture->GetSRV(),
                            "shader resource view of a texture of the TextureCache");

    SAFE_RELEASE(pTexture);

    return entry;
  }
}

void TextureCache::TCacheEntry::FromRenderTarget(bool is_depth_copy, const EFBRectangle& srcRect,
                                                 bool scaleByHalf, unsigned int cbufid,
                                                 const float* colmat)
{
  // When copying at half size, in multisampled mode, resolve the color/depth buffer first.
  // This is because multisampled texture reads go through Load, not Sample, and the linear
  // filter is ignored.
  bool multisampled = (g_ActiveConfig.iMultisamples > 1);
  ID3D11ShaderResourceView* efbTexSRV = is_depth_copy ?
                                            FramebufferManager::GetEFBDepthTexture()->GetSRV() :
                                            FramebufferManager::GetEFBColorTexture()->GetSRV();
  if (multisampled && scaleByHalf)
  {
    multisampled = false;
    efbTexSRV = is_depth_copy ? FramebufferManager::GetResolvedEFBDepthTexture()->GetSRV() :
                                FramebufferManager::GetResolvedEFBColorTexture()->GetSRV();
  }

  g_renderer->ResetAPIState();

  // stretch picture with increased internal resolution
  const D3D11_VIEWPORT vp = CD3D11_VIEWPORT(0.f, 0.f, (float)config.width, (float)config.height);
  D3D::context->RSSetViewports(1, &vp);

  // set transformation
  if (nullptr == efbcopycbuf[cbufid])
  {
    const D3D11_BUFFER_DESC cbdesc =
        CD3D11_BUFFER_DESC(28 * sizeof(float), D3D11_BIND_CONSTANT_BUFFER, D3D11_USAGE_DEFAULT);
    D3D11_SUBRESOURCE_DATA data;
    data.pSysMem = colmat;
    HRESULT hr = D3D::device->CreateBuffer(&cbdesc, &data, &efbcopycbuf[cbufid]);
    CHECK(SUCCEEDED(hr), "Create efb copy constant buffer %d", cbufid);
    D3D::SetDebugObjectName((ID3D11DeviceChild*)efbcopycbuf[cbufid],
                            "a constant buffer used in TextureCache::CopyRenderTargetToTexture");
  }
  D3D::stateman->SetPixelConstants(efbcopycbuf[cbufid]);

  const TargetRectangle targetSource = g_renderer->ConvertEFBRectangle(srcRect);
  // TODO: try targetSource.asRECT();
  const D3D11_RECT sourcerect =
      CD3D11_RECT(targetSource.left, targetSource.top, targetSource.right, targetSource.bottom);

  // Use linear filtering if (bScaleByHalf), use point filtering otherwise
  if (scaleByHalf)
    D3D::SetLinearCopySampler();
  else
    D3D::SetPointCopySampler();

  // Make sure we don't draw with the texture set as both a source and target.
  // (This can happen because we don't unbind textures when we free them.)
  D3D::stateman->UnsetTexture(texture->GetSRV());
  D3D::stateman->Apply();

  D3D::context->OMSetRenderTargets(1, &texture->GetRTV(), nullptr);

  // Create texture copy
  D3D::drawShadedTexQuad(
      efbTexSRV, &sourcerect, Renderer::GetTargetWidth(), Renderer::GetTargetHeight(),
      is_depth_copy ? PixelShaderCache::GetDepthMatrixProgram(multisampled) :
                      PixelShaderCache::GetColorMatrixProgram(multisampled),
      VertexShaderCache::GetSimpleVertexShader(), VertexShaderCache::GetSimpleInputLayout(),
      GeometryShaderCache::GetCopyGeometryShader());

  D3D::context->OMSetRenderTargets(1, &FramebufferManager::GetEFBColorTexture()->GetRTV(),
                                   FramebufferManager::GetEFBDepthTexture()->GetDSV());

  g_renderer->RestoreAPIState();
}

void TextureCache::CopyEFB(u8* dst, u32 format, u32 native_width, u32 bytes_per_row,
                           u32 num_blocks_y, u32 memory_stride, bool is_depth_copy,
                           const EFBRectangle& srcRect, bool isIntensity, bool scaleByHalf)
{
  g_encoder->Encode(dst, format, native_width, bytes_per_row, num_blocks_y, memory_stride,
                    is_depth_copy, srcRect, isIntensity, scaleByHalf);
}

const char palette_shader[] =
    R"HLSL(
sampler samp0 : register(s0);
Texture2DArray Tex0 : register(t0);
Buffer<uint> Tex1 : register(t1);
uniform float Multiply;

uint Convert3To8(uint v)
{
	// Swizzle bits: 00000123 -> 12312312
	return (v << 5) | (v << 2) | (v >> 1);
}

uint Convert4To8(uint v)
{
	// Swizzle bits: 00001234 -> 12341234
	return (v << 4) | v;
}

uint Convert5To8(uint v)
{
	// Swizzle bits: 00012345 -> 12345123
	return (v << 3) | (v >> 2);
}

uint Convert6To8(uint v)
{
	// Swizzle bits: 00123456 -> 12345612
	return (v << 2) | (v >> 4);
}

float4 DecodePixel_RGB5A3(uint val)
{
	int r,g,b,a;
	if ((val&0x8000))
	{
		r=Convert5To8((val>>10) & 0x1f);
		g=Convert5To8((val>>5 ) & 0x1f);
		b=Convert5To8((val    ) & 0x1f);
		a=0xFF;
	}
	else
	{
		a=Convert3To8((val>>12) & 0x7);
		r=Convert4To8((val>>8 ) & 0xf);
		g=Convert4To8((val>>4 ) & 0xf);
		b=Convert4To8((val    ) & 0xf);
	}
	return float4(r, g, b, a) / 255;
}

float4 DecodePixel_RGB565(uint val)
{
	int r, g, b, a;
	r = Convert5To8((val >> 11) & 0x1f);
	g = Convert6To8((val >> 5) & 0x3f);
	b = Convert5To8((val) & 0x1f);
	a = 0xFF;
	return float4(r, g, b, a) / 255;
}

float4 DecodePixel_IA8(uint val)
{
	int i = val & 0xFF;
	int a = val >> 8;
	return float4(i, i, i, a) / 255;
}

void main(
	out float4 ocol0 : SV_Target,
	in float4 pos : SV_Position,
	in float3 uv0 : TEXCOORD0)
{
	uint src = round(Tex0.Sample(samp0,uv0) * Multiply).r;
	src = Tex1.Load(src);
	src = ((src << 8) & 0xFF00) | (src >> 8);
	ocol0 = DECODE(src);
}
)HLSL";

void TextureCache::ConvertTexture(TCacheEntryBase* entry, TCacheEntryBase* unconverted,
                                  void* palette, TlutFormat format)
{
  g_renderer->ResetAPIState();

  // stretch picture with increased internal resolution
  const D3D11_VIEWPORT vp = CD3D11_VIEWPORT(0.f, 0.f, (float)unconverted->config.width,
                                            (float)unconverted->config.height);
  D3D::context->RSSetViewports(1, &vp);

  D3D11_BOX box{0, 0, 0, 512, 1, 1};
  D3D::context->UpdateSubresource(palette_buf, 0, &box, palette, 0, 0);

  D3D::stateman->SetTexture(1, palette_buf_srv);

  // TODO: Add support for C14X2 format.  (Different multiplier, more palette entries.)
  float params[4] = {(unconverted->format & 0xf) == GX_TF_I4 ? 15.f : 255.f};
  D3D::context->UpdateSubresource(palette_uniform, 0, nullptr, &params, 0, 0);
  D3D::stateman->SetPixelConstants(palette_uniform);

  const D3D11_RECT sourcerect =
      CD3D11_RECT(0, 0, unconverted->config.width, unconverted->config.height);

  D3D::SetPointCopySampler();

  // Make sure we don't draw with the texture set as both a source and target.
  // (This can happen because we don't unbind textures when we free them.)
  D3D::stateman->UnsetTexture(static_cast<TCacheEntry*>(entry)->texture->GetSRV());
  D3D::stateman->Apply();

  D3D::context->OMSetRenderTargets(1, &static_cast<TCacheEntry*>(entry)->texture->GetRTV(),
                                   nullptr);

  // Create texture copy
  D3D::drawShadedTexQuad(static_cast<TCacheEntry*>(unconverted)->texture->GetSRV(), &sourcerect,
                         unconverted->config.width, unconverted->config.height,
                         palette_pixel_shader[format], VertexShaderCache::GetSimpleVertexShader(),
                         VertexShaderCache::GetSimpleInputLayout(),
                         GeometryShaderCache::GetCopyGeometryShader());

  D3D::context->OMSetRenderTargets(1, &FramebufferManager::GetEFBColorTexture()->GetRTV(),
                                   FramebufferManager::GetEFBDepthTexture()->GetDSV());

  g_renderer->RestoreAPIState();
}

ID3D11PixelShader* GetConvertShader(const char* Type)
{
  std::string shader = "#define DECODE DecodePixel_";
  shader.append(Type);
  shader.append("\n");
  shader.append(palette_shader);
  return D3D::CompileAndCreatePixelShader(shader);
}

TextureCache::TextureCache()
{
  // FIXME: Is it safe here?
  g_encoder = std::make_unique<PSTextureEncoder>();
  g_encoder->Init();

  palette_buf = nullptr;
  palette_buf_srv = nullptr;
  palette_uniform = nullptr;
  palette_pixel_shader[GX_TL_IA8] = GetConvertShader("IA8");
  palette_pixel_shader[GX_TL_RGB565] = GetConvertShader("RGB565");
  palette_pixel_shader[GX_TL_RGB5A3] = GetConvertShader("RGB5A3");
  auto lutBd = CD3D11_BUFFER_DESC(sizeof(u16) * 256, D3D11_BIND_SHADER_RESOURCE);
  HRESULT hr = D3D::device->CreateBuffer(&lutBd, nullptr, &palette_buf);
  CHECK(SUCCEEDED(hr), "create palette decoder lut buffer");
  D3D::SetDebugObjectName(palette_buf, "texture decoder lut buffer");
  // TODO: C14X2 format.
  auto outlutUavDesc =
      CD3D11_SHADER_RESOURCE_VIEW_DESC(palette_buf, DXGI_FORMAT_R16_UINT, 0, 256, 0);
  hr = D3D::device->CreateShaderResourceView(palette_buf, &outlutUavDesc, &palette_buf_srv);
  CHECK(SUCCEEDED(hr), "create palette decoder lut srv");
  D3D::SetDebugObjectName(palette_buf_srv, "texture decoder lut srv");
  const D3D11_BUFFER_DESC cbdesc =
      CD3D11_BUFFER_DESC(16, D3D11_BIND_CONSTANT_BUFFER, D3D11_USAGE_DEFAULT);
  hr = D3D::device->CreateBuffer(&cbdesc, nullptr, &palette_uniform);
  CHECK(SUCCEEDED(hr), "Create palette decoder constant buffer");
  D3D::SetDebugObjectName((ID3D11DeviceChild*)palette_uniform,
                          "a constant buffer used in TextureCache::CopyRenderTargetToTexture");
}

TextureCache::~TextureCache()
{
  for (unsigned int k = 0; k < MAX_COPY_BUFFERS; ++k)
    SAFE_RELEASE(efbcopycbuf[k]);

  g_encoder->Shutdown();
  g_encoder.reset();

  SAFE_RELEASE(palette_buf);
  SAFE_RELEASE(palette_buf_srv);
  SAFE_RELEASE(palette_uniform);
  for (ID3D11PixelShader*& shader : palette_pixel_shader)
    SAFE_RELEASE(shader);
}
}