// 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/MsgHandler.h"
#include "Common/StringUtil.h"
#include "Common/Logging/Log.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;
}