#if _DEBUG

#include "ObjExporter.h"
#include <iostream>
#include <fstream>


void ObjExporter::Export(mt::Mesh* mesh, const std::string& filePath)
{
	ObjExporter exporter(mesh);
	exporter.Export(filePath);
}


ObjExporter::ObjExporter(mt::Mesh* mesh)
	: mesh{mesh}
{
}

void ObjExporter::Export(const std::string& filePath)
{
	std::ostringstream builder;
	std::ostringstream mtlBuilder;
	builder << "mtllib " + replace(filePath, ".obj", ".mtl") << std::endl;
	WritePositions(builder);
	WriteNormals(builder);
	WriteUVs(builder);
	WriteFaceGroups(builder, mtlBuilder);

	std::ofstream objFile(filePath);
	objFile << builder.str();
	objFile.close();

	std::ofstream mtlFile(replace(filePath, ".obj", ".mtl"));
	mtlFile << mtlBuilder.str();
	mtlFile.close();
}


void ObjExporter::WriteFaceGroups(std::ostringstream& builder, std::ostringstream& mtlBuilder)
{
	auto groups = mesh->GetSubMeshs();
	for(const auto& group : groups)
	{
		auto materialId = group->Key;

		builder << "usemtl " << materialId << std::endl;
		builder << "g " << materialId << std::endl;

		WriteFaces(builder, group->Value);

		mtlBuilder << "newmtl " << materialId << std::endl;
		mtlBuilder << "Ka  0.0 0.0 0.0" << std::endl;
		mtlBuilder << "Kd  1.0 1.0 1.0" << std::endl;
		mtlBuilder << "Ks  1.0 1.0 1.0" << std::endl;
		mtlBuilder << "Ns  16.0" << std::endl;
		mtlBuilder << "illum 0" << std::endl;

		mtlBuilder << "map_Kd " << materialId << ".png" << std::endl;
	}
}


void ObjExporter::WriteFaces(std::ostringstream& builder, const mt::FaceList& faces)
{
	for (auto face : faces)
	{
		auto indices = face->GetIndices(true);

		builder << "f";
		for (int i = 0; i < indices.Count(); ++i)
		{
			builder << " ";
			auto index = indices[i] + 1;
			builder << index << "/" << index << "/" << index;
		}
		builder << std::endl;
	}
}

void ObjExporter::WritePositions(std::ostringstream& builder)
{
	for (const auto& v : mesh->GetVertices())
	{
		builder << "v " << v->Position.x << " " << v->Position.y << " " << v->Position.z << std::endl;
	}
}

void ObjExporter::WriteNormals(std::ostringstream& builder)
{
	for (const auto& v : mesh->GetVertices())
	{
		auto normal = v->GetNormal();
		builder << "vn " << normal.x << " " << normal.y << " " << normal.z << std::endl;
	}
}

void ObjExporter::WriteUVs(std::ostringstream& builder)
{
	for (const auto& v : mesh->GetVertices())
	{
		builder << "vt " << v->UV[0] << " " << v->UV[1] << std::endl;
	}
}

#endif