/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

Copyright (c) 2006-2015, assimp team
All rights reserved.

Redistribution and use of this software in source and binary forms, 
with or without modification, are permitted provided that the 
following conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.

* Neither the name of the assimp team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the assimp team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

@author: Richard Steffen, 2015
----------------------------------------------------------------------
*/

#include "AssimpPCH.h"

#ifndef ASSIMP_BUILD_NO_EXPORT
#ifndef ASSIMP_BUILD_NO_STEP_EXPORTER
#include "StepExporter.h"
#include "ConvertToLHProcess.h"
#include "Bitmap.h"
#include "fast_atof.h"
#include "SceneCombiner.h" 

#include <ctime>
#include <set>
#include <map>
#include <list>

/* Tested with Step viewer v4 from www.ida-step.net */

using namespace Assimp;

namespace Assimp
{

// ------------------------------------------------------------------------------------------------
// Worker function for exporting a scene to Collada. Prototyped and registered in Exporter.cpp
void ExportSceneStep(const char* pFile,IOSystem* pIOSystem, const aiScene* pScene, const ExportProperties* pProperties)
{
	std::string path = "";
	std::string file = pFile;

	// We need to test both types of folder separators because pIOSystem->getOsSeparator() is not reliable.
	// Moreover, the path given by some applications is not even consistent with the OS specific type of separator.
	const char* end_path = std::max(strrchr(pFile, '\\'), strrchr(pFile, '/'));

	if(end_path != NULL) {
		path = std::string(pFile, end_path + 1 - pFile);
		file = file.substr(end_path + 1 - pFile, file.npos);

		std::size_t pos = file.find_last_of('.');
		if(pos != file.npos) {
			file = file.substr(0, pos);
		}
	}

	// create/copy Properties
	ExportProperties props(*pProperties);

	// set standard properties if not set
	//if (!props.HasPropertyBool(AI_CONFIG_EXPORT_XFILE_64BIT)) props.SetPropertyBool(AI_CONFIG_EXPORT_XFILE_64BIT, false);

	// invoke the exporter 
	StepExporter iDoTheExportThing( pScene, pIOSystem, path, file, &props);

	// we're still here - export successfully completed. Write result to the given IOSYstem
	boost::scoped_ptr<IOStream> outfile (pIOSystem->Open(pFile,"wt"));
	if(outfile == NULL) {
		throw DeadlyExportError("could not open output .stp file: " + std::string(pFile));
	}

	// XXX maybe use a small wrapper around IOStream that behaves like std::stringstream in order to avoid the extra copy.
	outfile->Write( iDoTheExportThing.mOutput.str().c_str(), static_cast<size_t>(iDoTheExportThing.mOutput.tellp()),1);
}

} // end of namespace Assimp


namespace {
inline uint64_t toIndexHash(int32_t id1, int32_t id2)
{
	// dont wonder that -1/-1 -> hash=-1
    uint64_t hash = (uint32_t) id1;
    hash = (hash << 32);
    hash += (uint32_t) id2;
    return hash;
}

inline void fromIndexHash(uint64_t hash, int32_t &id1, int32_t &id2)
{
    id1 = (hash & 0xFFFFFFFF00000000) >> 32;
    id2 = (hash & 0xFFFFFFFF);
}

// Collect world transformations for each node
	void CollectTrafos(const aiNode* node, std::map<const aiNode*, aiMatrix4x4>& trafos) {
		const aiMatrix4x4& parent = node->mParent ? trafos[node->mParent] : aiMatrix4x4();
		trafos[node] = parent * node->mTransformation;
		for (unsigned int i = 0; i < node->mNumChildren; ++i) {
			CollectTrafos(node->mChildren[i], trafos);
		}
	}

	// Generate a flat list of the meshes (by index) assigned to each node
	void CollectMeshes(const aiNode* node, std::multimap<const aiNode*, unsigned int>& meshes) {
		for (unsigned int i = 0; i < node->mNumMeshes; ++i) {
			meshes.insert(std::make_pair(node, node->mMeshes[i]));
		}
		for (unsigned int i = 0; i < node->mNumChildren; ++i) {
			CollectMeshes(node->mChildren[i], meshes);
		}
	}
}

// ------------------------------------------------------------------------------------------------
// Constructor for a specific scene to export
StepExporter::StepExporter(const aiScene* pScene, IOSystem* pIOSystem, const std::string& path, const std::string& file, const ExportProperties* pProperties) : mIOSystem(pIOSystem), mPath(path), mFile(file), mProperties(pProperties)
{
	CollectTrafos(pScene->mRootNode, trafos);
	CollectMeshes(pScene->mRootNode, meshes);

	// make sure that all formatting happens using the standard, C locale and not the user's current locale
	mOutput.imbue( std::locale("C") );

	mFile = std::string(file);
	mPath = std::string(path);
	mScene = pScene;
	mSceneOwned = false;

	// set up strings
	endstr = ";\n"; 

	// start writing
	WriteFile();



}

// ------------------------------------------------------------------------------------------------
// Destructor
StepExporter::~StepExporter()
{
	if(mSceneOwned) {
		delete mScene;
	}
}

// ------------------------------------------------------------------------------------------------
// Starts writing the contents
void StepExporter::WriteFile()
{
	// see http://shodhganga.inflibnet.ac.in:8080/jspui/bitstream/10603/14116/11/11_chapter%203.pdf
	// note, that all realnumber values must be comma separated in x files
	mOutput.setf(std::ios::fixed);
	mOutput.precision(16); // precission for double

	aiMatrix4x4 baseTransform = mScene->mRootNode->mTransformation;

	int ind = 100; // the start index to be used
	int faceEntryLen = 30; // number of entries for a triangle/face
	// prepare unique (count triangles and vertices)
	std::map<aiVector3D*, int> uniqueVerts; // use a map to reduce find complexity to log(n)
	std::map<aiVector3D*, int>::iterator it;
	int countFace = 0;

	for (unsigned int i=0; i<mScene->mNumMeshes; ++i)
	{
		aiMesh* mesh = mScene->mMeshes[i];		
		for (unsigned int j=0; j<mesh->mNumFaces; ++j)
		{
			aiFace* face = &(mesh->mFaces[j]);

			if (face->mNumIndices == 3) countFace++;
		}
		for (unsigned int j=0; j<mesh->mNumVertices; ++j)
		{
			aiVector3D* v = &(mesh->mVertices[j]);
			it =uniqueVerts.find(v); 
			if (it == uniqueVerts.end())
			{
				uniqueVerts[v] = -1; // first mark the vector as not transformed
			}
		}
	}

	// write the header	
	mOutput << "ISO-10303-21" << endstr;
	mOutput << "HEADER" << endstr;
	mOutput << "FILE_DESCRIPTION(('STEP AP214'),'1')" << endstr;
	mOutput << "FILE_NAME('" << mFile << ".stp','2015-04-23T09:26:41',(' '),(' '),'Spatial InterOp 3D',' ',' ')" << endstr;
	mOutput << "FILE_SCHEMA(('automotive_design'))" << endstr;
	mOutput << "ENDSEC" << endstr;

	// write the top of data
	mOutput << "DATA" << endstr;
	mOutput << "#1=MECHANICAL_DESIGN_GEOMETRIC_PRESENTATION_REPRESENTATION(' ',(";
	for (int i=0; i<countFace; ++i)
	{
		mOutput << "#" << i*faceEntryLen + ind + 2*uniqueVerts.size();
		if (i!=countFace-1) mOutput << ",";
	}
	mOutput << "),#6)" << endstr;

	mOutput << "#2=PRODUCT_DEFINITION_CONTEXT('',#7,'design')" << endstr;
	mOutput << "#3=APPLICATION_PROTOCOL_DEFINITION('INTERNATIONAL STANDARD','automotive_design',1994,#7)" << endstr;
	mOutput << "#4=PRODUCT_CATEGORY_RELATIONSHIP('NONE','NONE',#8,#9)" << endstr;
	mOutput << "#5=SHAPE_DEFINITION_REPRESENTATION(#10,#11)" << endstr;
	mOutput << "#6= (GEOMETRIC_REPRESENTATION_CONTEXT(3)GLOBAL_UNCERTAINTY_ASSIGNED_CONTEXT((#12))GLOBAL_UNIT_ASSIGNED_CONTEXT((#13,#14,#15))REPRESENTATION_CONTEXT('NONE','WORKSPACE'))" << endstr;
	mOutput << "#7=APPLICATION_CONTEXT(' ')" << endstr;
	mOutput << "#8=PRODUCT_CATEGORY('part','NONE')" << endstr;
	mOutput << "#9=PRODUCT_RELATED_PRODUCT_CATEGORY('detail',' ',(#17))" << endstr;
	mOutput << "#10=PRODUCT_DEFINITION_SHAPE('NONE','NONE',#18)" << endstr;
	mOutput << "#11=MANIFOLD_SURFACE_SHAPE_REPRESENTATION('Root',(#16,#19),#6)" << endstr;
	mOutput << "#12=UNCERTAINTY_MEASURE_WITH_UNIT(LENGTH_MEASURE(1.0E-006),#13,'','')" << endstr;
	mOutput << "#13=(CONVERSION_BASED_UNIT('METRE',#20)LENGTH_UNIT()NAMED_UNIT(#21))" << endstr;
	mOutput << "#14=(NAMED_UNIT(#22)PLANE_ANGLE_UNIT()SI_UNIT($,.RADIAN.))" << endstr;
	mOutput << "#15=(NAMED_UNIT(#22)SOLID_ANGLE_UNIT()SI_UNIT($,.STERADIAN.))" << endstr;
	mOutput << "#16=SHELL_BASED_SURFACE_MODEL('Root',(#29))" << endstr;
	mOutput << "#17=PRODUCT('Root','Root','Root',(#23))" << endstr;
	mOutput << "#18=PRODUCT_DEFINITION('NONE','NONE',#24,#2)" << endstr;
	mOutput << "#19=AXIS2_PLACEMENT_3D('',#25,#26,#27)" << endstr;
	mOutput << "#20=LENGTH_MEASURE_WITH_UNIT(LENGTH_MEASURE(1.0),#28)" << endstr;
	mOutput << "#21=DIMENSIONAL_EXPONENTS(1.0,0.0,0.0,0.0,0.0,0.0,0.0)" << endstr;
	mOutput << "#22=DIMENSIONAL_EXPONENTS(0.0,0.0,0.0,0.0,0.0,0.0,0.0)" << endstr;
	mOutput << "#23=PRODUCT_CONTEXT('',#7,'mechanical')" << endstr;
	mOutput << "#24=PRODUCT_DEFINITION_FORMATION_WITH_SPECIFIED_SOURCE(' ','NONE',#17,.NOT_KNOWN.)" << endstr;
	mOutput << "#25=CARTESIAN_POINT('',(0.0,0.0,0.0))" << endstr;
	mOutput << "#26=DIRECTION('',(0.0,0.0,1.0))" << endstr;
	mOutput << "#27=DIRECTION('',(1.0,0.0,0.0))" << endstr;	

	mOutput << "#28= (NAMED_UNIT(#21)LENGTH_UNIT()SI_UNIT(.MILLI.,.METRE.))" << endstr;


	mOutput << "#29=CLOSED_SHELL('',(";
	for (int i=0; i<countFace; ++i)
	{
		mOutput << "#" << i*faceEntryLen + ind + 2*uniqueVerts.size() + 8;
		if (i!=countFace-1) mOutput << ",";
	}
	mOutput << "))" << endstr;

	// write all the unique transformed CARTESIAN and VERTEX
	for (MeshesByNodeMap::const_iterator it2 = meshes.begin(); it2 != meshes.end(); it2++)
	{
		const aiNode& node = *(*it2).first;
		unsigned int mesh_idx = (*it2).second;

		const aiMesh* mesh = mScene->mMeshes[mesh_idx];
		aiMatrix4x4& trafo = trafos[&node];
		for (unsigned int i = 0; i < mesh->mNumVertices; ++i)
		{
			aiVector3D* v = &(mesh->mVertices[i]);
			it = uniqueVerts.find(v);
			if (it->second >=0 ) continue;
			it->second = ind; // this one is new, so set the index (ind)
			aiVector3D vt = trafo * (*v); // transform the coordinate
			mOutput << "#" << it->second << "=CARTESIAN_POINT('',(" << vt.x << "," << vt.y << "," << vt.z << "))" << endstr;
			mOutput << "#" << it->second+1 << "=VERTEX_POINT('',#" << it->second << ")" << endstr;
			ind += 2;
		}
	}

	// write the triangles
	for (unsigned int i=0; i<mScene->mNumMeshes; ++i)
	{
		aiMesh* mesh = mScene->mMeshes[i];		
		for (unsigned int j=0; j<mesh->mNumFaces; ++j)
		{
			aiFace* face = &(mesh->mFaces[j]);

			if (face->mNumIndices != 3) continue;
	
			aiVector3D* v1 = &(mesh->mVertices[face->mIndices[0]]);
			aiVector3D* v2 = &(mesh->mVertices[face->mIndices[1]]);
			aiVector3D* v3 = &(mesh->mVertices[face->mIndices[2]]);
			aiVector3D dv12 = *v2 - *v1;
			aiVector3D dv23 = *v3 - *v2;
			aiVector3D dv31 = *v1 - *v3;
			aiVector3D dv13 = *v3 - *v1;
			dv12.Normalize();
			dv23.Normalize();
			dv31.Normalize();
			dv13.Normalize();

			int pid1 = uniqueVerts.find(v1)->second;
			int pid2 = uniqueVerts.find(v2)->second;
			int pid3 = uniqueVerts.find(v3)->second;

			int sid = ind; // the sub index		
			mOutput << "#" << sid << "=STYLED_ITEM('',(#" << sid+1 << "),#" << sid+8 << ")" << endstr; /* the item that must be referenced in #1 */
			/* This is the color information of the Triangle */
			mOutput << "#" << sid+1 << "=PRESENTATION_STYLE_ASSIGNMENT((#" << sid+2 << "))" << endstr;
			mOutput << "#" << sid+2 << "=SURFACE_STYLE_USAGE(.BOTH.,#" << sid+3 << ")" << endstr;
			mOutput << "#" << sid+3 << "=SURFACE_SIDE_STYLE('',(#" << sid+4 << "))" << endstr;
			mOutput << "#" << sid+4 << "=SURFACE_STYLE_FILL_AREA(#" << sid+5 << ")" << endstr;
			mOutput << "#" << sid+5 << "=FILL_AREA_STYLE('',(#" << sid+6 << "))" << endstr;
			mOutput << "#" << sid+6 << "=FILL_AREA_STYLE_COLOUR('',#" << sid+7 << ")" << endstr;
			mOutput << "#" << sid+7 << "=COLOUR_RGB('',0.0,0.0,1.0)" << endstr;

			/* this is the geometry */
			mOutput << "#" << sid+8 << "=FACE_SURFACE('',(#" << sid+13 << "),#" << sid+9<< ",.T.)" << endstr; /* the face that must be referenced in 29 */

			/* 2 directions of the plane */
			mOutput << "#" << sid+9 << "=PLANE('',#" << sid+10 << ")" << endstr;
			mOutput << "#" << sid+10 << "=AXIS2_PLACEMENT_3D('',#" << pid1 << ", #" << sid+11 << ",#" << sid+12 << ")" << endstr;									

			mOutput << "#" << sid+11 << "=DIRECTION('',(" << dv12.x << "," << dv12.y << "," << dv12.z << "))" << endstr;
			mOutput << "#" << sid+12 << "=DIRECTION('',(" << dv13.x << "," << dv13.y << "," << dv13.z << "))" << endstr;

			mOutput << "#" << sid+13 << "=FACE_BOUND('',#" << sid+14 << ",.T.)" << endstr;
			mOutput << "#" << sid+14 << "=EDGE_LOOP('',(#" << sid+15 << ",#" << sid+16 << ",#" << sid+17 << "))" << endstr;

			/* edge loop  */
			mOutput << "#" << sid+15 << "=ORIENTED_EDGE('',*,*,#" << sid+18 << ",.T.)" << endstr;
			mOutput << "#" << sid+16 << "=ORIENTED_EDGE('',*,*,#" << sid+19 << ",.T.)" << endstr;
			mOutput << "#" << sid+17 << "=ORIENTED_EDGE('',*,*,#" << sid+20 << ",.T.)" << endstr;

			/* oriented edges */
			mOutput << "#" << sid+18 << "=EDGE_CURVE('',#" << pid1+1 << ",#" << pid2+1 << ",#" << sid+21 << ",.F.)" << endstr;
			mOutput << "#" << sid+19 << "=EDGE_CURVE('',#" << pid2+1 << ",#" << pid3+1 << ",#" << sid+22 << ",.T.)" << endstr;
			mOutput << "#" << sid+20 << "=EDGE_CURVE('',#" << pid3+1 << ",#" << pid1+1 << ",#" << sid+23 << ",.T.)" << endstr;

			/* 3 lines and 3 vectors for the lines for the 3 edge curves */
			mOutput << "#" << sid+21 << "=LINE('',#" << pid1 << ",#" << sid+24 << ")" << endstr;
			mOutput << "#" << sid+22 << "=LINE('',#" << pid2 << ",#" << sid+25 << ")" << endstr;
			mOutput << "#" << sid+23 << "=LINE('',#" << pid3 << ",#" << sid+26 << ")" << endstr;
			mOutput << "#" << sid+24 << "=VECTOR('',#" << sid+27 << ",1.0)" << endstr;
			mOutput << "#" << sid+25 << "=VECTOR('',#" << sid+28 << ",1.0)" << endstr;
			mOutput << "#" << sid+26 << "=VECTOR('',#" << sid+29 << ",1.0)" << endstr;
			mOutput << "#" << sid+27 << "=DIRECTION('',(" << dv12.x << "," << dv12.y << "," << dv12.z << "))" << endstr;
			mOutput << "#" << sid+28 << "=DIRECTION('',(" << dv23.x << "," << dv23.y << "," << dv23.z << "))" << endstr;
			mOutput << "#" << sid+29 << "=DIRECTION('',(" << dv31.x << "," << dv31.y << "," << dv31.z << "))" << endstr;
			ind += faceEntryLen; // increase counter
		}
	}
		
	mOutput << "ENDSEC" << endstr; // end of data section	
	mOutput << "END-ISO-10303-21" << endstr; // end of file
}



#endif
#endif