// Copyright 2014 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include <cinttypes>
#include <cstring>
#include <memory>
#include <string>
#include <vector>

#include "Common/CommonTypes.h"
#include "Common/Logging/Log.h"
#include "Common/MsgHandler.h"
#include "Common/StringUtil.h"

#include "VideoCommon/DataReader.h"
#include "VideoCommon/VertexLoader.h"
#include "VideoCommon/VertexLoaderBase.h"

#ifdef _M_X86_64
#include "VideoCommon/VertexLoaderX64.h"
#elif defined(_M_ARM_64)
#include "VideoCommon/VertexLoaderARM64.h"
#endif

VertexLoaderBase::VertexLoaderBase(const TVtxDesc& vtx_desc, const VAT& vtx_attr)
{
  m_numLoadedVertices = 0;
  m_VertexSize = 0;
  m_native_vertex_format = nullptr;
  m_native_components = 0;
  memset(&m_native_vtx_decl, 0, sizeof(m_native_vtx_decl));

  SetVAT(vtx_attr);
  m_VtxDesc = vtx_desc;
  m_vat = vtx_attr;
}

void VertexLoaderBase::SetVAT(const VAT& vat)
{
  m_VtxAttr.PosElements = vat.g0.PosElements;
  m_VtxAttr.PosFormat = vat.g0.PosFormat;
  m_VtxAttr.PosFrac = vat.g0.PosFrac;
  m_VtxAttr.NormalElements = vat.g0.NormalElements;
  m_VtxAttr.NormalFormat = vat.g0.NormalFormat;
  m_VtxAttr.color[0].Elements = vat.g0.Color0Elements;
  m_VtxAttr.color[0].Comp = vat.g0.Color0Comp;
  m_VtxAttr.color[1].Elements = vat.g0.Color1Elements;
  m_VtxAttr.color[1].Comp = vat.g0.Color1Comp;
  m_VtxAttr.texCoord[0].Elements = vat.g0.Tex0CoordElements;
  m_VtxAttr.texCoord[0].Format = vat.g0.Tex0CoordFormat;
  m_VtxAttr.texCoord[0].Frac = vat.g0.Tex0Frac;
  m_VtxAttr.ByteDequant = vat.g0.ByteDequant;
  m_VtxAttr.NormalIndex3 = vat.g0.NormalIndex3;

  m_VtxAttr.texCoord[1].Elements = vat.g1.Tex1CoordElements;
  m_VtxAttr.texCoord[1].Format = vat.g1.Tex1CoordFormat;
  m_VtxAttr.texCoord[1].Frac = vat.g1.Tex1Frac;
  m_VtxAttr.texCoord[2].Elements = vat.g1.Tex2CoordElements;
  m_VtxAttr.texCoord[2].Format = vat.g1.Tex2CoordFormat;
  m_VtxAttr.texCoord[2].Frac = vat.g1.Tex2Frac;
  m_VtxAttr.texCoord[3].Elements = vat.g1.Tex3CoordElements;
  m_VtxAttr.texCoord[3].Format = vat.g1.Tex3CoordFormat;
  m_VtxAttr.texCoord[3].Frac = vat.g1.Tex3Frac;
  m_VtxAttr.texCoord[4].Elements = vat.g1.Tex4CoordElements;
  m_VtxAttr.texCoord[4].Format = vat.g1.Tex4CoordFormat;

  m_VtxAttr.texCoord[4].Frac = vat.g2.Tex4Frac;
  m_VtxAttr.texCoord[5].Elements = vat.g2.Tex5CoordElements;
  m_VtxAttr.texCoord[5].Format = vat.g2.Tex5CoordFormat;
  m_VtxAttr.texCoord[5].Frac = vat.g2.Tex5Frac;
  m_VtxAttr.texCoord[6].Elements = vat.g2.Tex6CoordElements;
  m_VtxAttr.texCoord[6].Format = vat.g2.Tex6CoordFormat;
  m_VtxAttr.texCoord[6].Frac = vat.g2.Tex6Frac;
  m_VtxAttr.texCoord[7].Elements = vat.g2.Tex7CoordElements;
  m_VtxAttr.texCoord[7].Format = vat.g2.Tex7CoordFormat;
  m_VtxAttr.texCoord[7].Frac = vat.g2.Tex7Frac;
};

void VertexLoaderBase::AppendToString(std::string* dest) const
{
  dest->reserve(250);

  dest->append(GetName());
  dest->append(": ");

  static const char* posMode[4] = {
      "Inv", "Dir", "I8", "I16",
  };
  static const char* posFormats[8] = {
      "u8", "s8", "u16", "s16", "flt", "Inv", "Inv", "Inv",
  };
  static const char* colorFormat[8] = {
      "565", "888", "888x", "4444", "6666", "8888", "Inv", "Inv",
  };

  dest->append(StringFromFormat("%ib skin: %i P: %i %s-%s ", m_VertexSize, (u32)m_VtxDesc.PosMatIdx,
                                m_VtxAttr.PosElements ? 3 : 2, posMode[m_VtxDesc.Position],
                                posFormats[m_VtxAttr.PosFormat]));

  if (m_VtxDesc.Normal)
  {
    dest->append(StringFromFormat("Nrm: %i %s-%s ", m_VtxAttr.NormalElements,
                                  posMode[m_VtxDesc.Normal], posFormats[m_VtxAttr.NormalFormat]));
  }

  u64 color_mode[2] = {m_VtxDesc.Color0, m_VtxDesc.Color1};
  for (int i = 0; i < 2; i++)
  {
    if (color_mode[i])
    {
      dest->append(StringFromFormat("C%i: %i %s-%s ", i, m_VtxAttr.color[i].Elements,
                                    posMode[color_mode[i]], colorFormat[m_VtxAttr.color[i].Comp]));
    }
  }
  u64 tex_mode[8] = {m_VtxDesc.Tex0Coord, m_VtxDesc.Tex1Coord, m_VtxDesc.Tex2Coord,
                     m_VtxDesc.Tex3Coord, m_VtxDesc.Tex4Coord, m_VtxDesc.Tex5Coord,
                     m_VtxDesc.Tex6Coord, m_VtxDesc.Tex7Coord};
  for (int i = 0; i < 8; i++)
  {
    if (tex_mode[i])
    {
      dest->append(StringFromFormat("T%i: %i %s-%s ", i, m_VtxAttr.texCoord[i].Elements,
                                    posMode[tex_mode[i]],
                                    posFormats[m_VtxAttr.texCoord[i].Format]));
    }
  }
  dest->append(StringFromFormat(" - %i v", m_numLoadedVertices));
}

// a hacky implementation to compare two vertex loaders
class VertexLoaderTester : public VertexLoaderBase
{
public:
  VertexLoaderTester(std::unique_ptr<VertexLoaderBase> a_, std::unique_ptr<VertexLoaderBase> b_,
                     const TVtxDesc& vtx_desc, const VAT& vtx_attr)
      : VertexLoaderBase(vtx_desc, vtx_attr), a(std::move(a_)), b(std::move(b_))
  {
    m_initialized = a && b && a->IsInitialized() && b->IsInitialized();

    if (m_initialized)
    {
      m_initialized = a->m_VertexSize == b->m_VertexSize &&
                      a->m_native_components == b->m_native_components &&
                      a->m_native_vtx_decl.stride == b->m_native_vtx_decl.stride;

      if (m_initialized)
      {
        m_VertexSize = a->m_VertexSize;
        m_native_components = a->m_native_components;
        memcpy(&m_native_vtx_decl, &a->m_native_vtx_decl, sizeof(PortableVertexDeclaration));
      }
      else
      {
        ERROR_LOG(VIDEO, "Can't compare vertex loaders that expect different vertex formats!");
        ERROR_LOG(VIDEO, "a: m_VertexSize %d, m_native_components 0x%08x, stride %d",
                  a->m_VertexSize, a->m_native_components, a->m_native_vtx_decl.stride);
        ERROR_LOG(VIDEO, "b: m_VertexSize %d, m_native_components 0x%08x, stride %d",
                  b->m_VertexSize, b->m_native_components, b->m_native_vtx_decl.stride);
      }
    }
  }
  ~VertexLoaderTester() override {}
  int RunVertices(DataReader src, DataReader dst, int count) override
  {
    buffer_a.resize(count * a->m_native_vtx_decl.stride + 4);
    buffer_b.resize(count * b->m_native_vtx_decl.stride + 4);

    int count_a =
        a->RunVertices(src, DataReader(buffer_a.data(), buffer_a.data() + buffer_a.size()), count);
    int count_b =
        b->RunVertices(src, DataReader(buffer_b.data(), buffer_b.data() + buffer_b.size()), count);

    if (count_a != count_b)
      ERROR_LOG(VIDEO,
                "The two vertex loaders have loaded a different amount of vertices (a: %d, b: %d).",
                count_a, count_b);

    if (memcmp(buffer_a.data(), buffer_b.data(),
               std::min(count_a, count_b) * m_native_vtx_decl.stride))
      ERROR_LOG(VIDEO, "The two vertex loaders have loaded different data "
                       "(guru meditation 0x%016" PRIx64 ", 0x%08x, 0x%08x, 0x%08x).",
                m_VtxDesc.Hex, m_vat.g0.Hex, m_vat.g1.Hex, m_vat.g2.Hex);

    memcpy(dst.GetPointer(), buffer_a.data(), count_a * m_native_vtx_decl.stride);
    m_numLoadedVertices += count;
    return count_a;
  }
  std::string GetName() const override { return "CompareLoader"; }
  bool IsInitialized() override { return m_initialized; }
private:
  bool m_initialized;

  std::unique_ptr<VertexLoaderBase> a;
  std::unique_ptr<VertexLoaderBase> b;

  std::vector<u8> buffer_a;
  std::vector<u8> buffer_b;
};

std::unique_ptr<VertexLoaderBase> VertexLoaderBase::CreateVertexLoader(const TVtxDesc& vtx_desc,
                                                                       const VAT& vtx_attr)
{
  std::unique_ptr<VertexLoaderBase> loader;

//#define COMPARE_VERTEXLOADERS

#if defined(COMPARE_VERTEXLOADERS) && defined(_M_X86_64)
  // first try: Any new VertexLoader vs the old one
  loader = std::make_unique<VertexLoaderTester>(
      std::make_unique<VertexLoader>(vtx_desc, vtx_attr),     // the software one
      std::make_unique<VertexLoaderX64>(vtx_desc, vtx_attr),  // the new one to compare
      vtx_desc, vtx_attr);
  if (loader->IsInitialized())
    return loader;
#elif defined(_M_X86_64)
  loader = std::make_unique<VertexLoaderX64>(vtx_desc, vtx_attr);
  if (loader->IsInitialized())
    return loader;
#elif defined(_M_ARM_64)
  loader = std::make_unique<VertexLoaderARM64>(vtx_desc, vtx_attr);
  if (loader->IsInitialized())
    return loader;
#endif

  // last try: The old VertexLoader
  loader = std::make_unique<VertexLoader>(vtx_desc, vtx_attr);
  if (loader->IsInitialized())
    return loader;

  PanicAlert("No Vertex Loader found.");
  return nullptr;
}