#include "..\Header\MshFile.h"
#include <iostream>


// helper function to save data from file to any variable type
#define F2V(variableName) reinterpret_cast<char*>(&variableName)


/////////////////////////////////////////////////////////////////////////
// public constructor/destructor

MshFile::MshFile(const char * path)
	: FileInterface(path)
{
	import();
}

MshFile::~MshFile()
{
}


/////////////////////////////////////////////////////////////////////////
// private functions

void MshFile::import()
{
	// go to file size information
	m_file.seekg(4);

	std::uint32_t tmp_fileSize;
	std::list<ChunkHeader*> tmp_mainChunks;

	// get all chunks under HEDR
	m_file.read(F2V(tmp_fileSize), sizeof(tmp_fileSize));
	loadChunks(tmp_mainChunks, m_file.tellg(), tmp_fileSize);

	// evaulate HEDR subchunks (= find MSH2)
	for (ChunkHeader* it : tmp_mainChunks)
	{
		if (!strcmp("MSH2", it->name))
		{
			// get all subchunks
			std::list<ChunkHeader*> tmp_msh2Chunks;
			loadChunks(tmp_msh2Chunks, it->position, it->size);

			// evaluate MSH2 subchunks
			analyseMsh2Chunks(tmp_msh2Chunks);

			// clean up
			while (!tmp_msh2Chunks.empty())
			{
				ChunkHeader* curs = tmp_msh2Chunks.front();
				tmp_msh2Chunks.pop_front();
				delete curs;
			}
		}
	}

	// clean up
	while (!tmp_mainChunks.empty())
	{
		ChunkHeader* cur = tmp_mainChunks.front();
		tmp_mainChunks.pop_front();
		delete cur;
	}
}

void MshFile::loadChunks(std::list<ChunkHeader*>& destination, std::streampos start, const std::uint32_t length)
{
	// jump to first chunk
	m_file.seekg(start);

	do
	{
		ChunkHeader* tmp_header = new ChunkHeader();

		// get information
		m_file.read(F2V(tmp_header->name[0]), sizeof(tmp_header->name) - 1);
		m_file.read(F2V(tmp_header->size), sizeof(tmp_header->size));
		tmp_header->position = m_file.tellg();

		// store information
		destination.push_back(tmp_header);

		// jump to next header
		m_file.seekg(tmp_header->size, std::ios_base::cur);

		// out of file. Maybe a size information is corrupted
		if (!m_file.good())
		{
			//TODO: different way for output
			std::cout << "WARNING: corrupted file. Trying to continue" << std::endl;
			m_file.clear();
			break;
		}

	} while (m_file.tellg() - start != length);
}

void MshFile::analyseMsh2Chunks(std::list<ChunkHeader*>& chunkList)
{
	for (auto& it : chunkList)
	{
		// scene information
		if (!strcmp("SINF", it->name))
		{
			// get SINF subchunks
			std::list<ChunkHeader*> tmp_sinfChunks;
			loadChunks(tmp_sinfChunks, it->position, it->size);

			// evaluate SINF subchunks
			for (auto& it : tmp_sinfChunks)
			{
				if (!strcmp("BBOX", it->name))
				{
					m_file.seekg(it->position);

					// read in the quaternion
					float tmp_quat[4];
					for (int i = 0; i < 4; i++)
						m_file.read(F2V(tmp_quat[i]), sizeof(float));

					m_sceneBbox.rotation.setX(tmp_quat[0]);
					m_sceneBbox.rotation.setY(tmp_quat[1]);
					m_sceneBbox.rotation.setZ(tmp_quat[2]);
					m_sceneBbox.rotation.setScalar(tmp_quat[3]);

					//read in the center
					for (int i = 0; i < 3; i++)
						m_file.read(F2V(m_sceneBbox.center[i]), sizeof(float));

					//read in the extents
					for (int i = 0; i < 3; i++)
						m_file.read(F2V(m_sceneBbox.extents[i]), sizeof(float));
				}
			}

			// clean up SINF subchunks
			for (ChunkHeader* it : tmp_sinfChunks)
				delete it;
		}

		// material list
		else if (!strcmp("MATL", it->name))
		{
			// "useless" information how many MATD follow, jump over it
			m_file.seekg(it->position);
			m_file.seekg(sizeof(std::uint32_t), std::ios_base::cur);

			// get all MATL subchunk
			std::list<ChunkHeader*> tmp_matlChunks;
			loadChunks(tmp_matlChunks, m_file.tellg(), it->size - 4);

			// evaluate MATL subchunks
			for (auto& it : tmp_matlChunks)
			{
				// This shouldn't be anything else than MATD
				if (!strcmp("MATD", it->name))
				{
					// get all subchunks from MATD
					std::list<ChunkHeader*> tmp_matdChunks;
					loadChunks(tmp_matdChunks, it->position, it->size);

					m_textureNames->push_back("");

					// analyse MATD subchunks
					analyseMatdChunks(tmp_matdChunks);

					// clean up MATD subchunks
					while (!tmp_matdChunks.empty())
					{
						ChunkHeader* cur = tmp_matdChunks.front();
						tmp_matdChunks.pop_front();
						delete cur;
					}
				}
			}

			// clean up MATL subchunks
			while (!tmp_matlChunks.empty())
			{
				ChunkHeader* cur = tmp_matlChunks.front();
				tmp_matlChunks.pop_front();
				delete cur;
			}
		}

		// model
		else if (!strcmp("MODL", it->name))
		{
			Model* new_model = new Model;
			m_currentType = ModelTyp::null;
			m_currentRenderFlag = -1;

			// get all MODL subchunks
			std::list<ChunkHeader*> tmp_chunks;
			loadChunks(tmp_chunks, it->position, it->size);

			// evaluate MODL subchunks
			analyseModlChunks(new_model, tmp_chunks);

			//clean up MODL subchunks
			while (!tmp_chunks.empty())
			{
				ChunkHeader* cur = tmp_chunks.front();
				tmp_chunks.pop_front();
				delete cur;
			}

			// save Model data
			m_models->push_back(new_model);
		}
	}
}

void MshFile::analyseMatdChunks(std::list<ChunkHeader*>& chunkList)
{
	for (auto& it : chunkList)
	{
		if (!strcmp("TX0D", it->name))
		{
			m_file.seekg(it->position);
			char* buffer = new char[it->size + 1];
			*buffer = { 0 };
			m_file.read(buffer, it->size);
			m_textureNames->back() = buffer;
			delete[] buffer;
		}
	}
}

void MshFile::analyseModlChunks(Model * dataDestination, std::list<ChunkHeader*>& chunkList)
{
	for (auto& it : chunkList)
	{
		// model type
		if (!strcmp("MTYP", it->name))
		{
			m_file.seekg(it->position);
			std::uint32_t tmp_type;
			m_file.read(F2V(tmp_type), sizeof(tmp_type));
			m_currentType = (ModelTyp)tmp_type;
		}

		// parent name
		else if (!strcmp("PRNT", it->name))
		{
			m_file.seekg(it->position);
			char* buffer = new char[it->size + 1];
			*buffer = { 0 };
			m_file.read(buffer, it->size);
			dataDestination->parent = buffer;
			delete[] buffer;
		}

		// model name
		else if (!strcmp("NAME", it->name))
		{
			m_file.seekg(it->position);
			char* buffer = new char[it->size + 1];
			*buffer = { 0 };
			m_file.read(buffer, it->size);
			dataDestination->name = buffer;
			delete[] buffer;
		}

		// render flags
		else if (!strcmp("FLGS", it->name))
		{
			m_file.seekg(it->position);
			m_file.read(F2V(m_currentRenderFlag), sizeof(m_currentRenderFlag));
		}

		// translation
		else if (!strcmp("TRAN", it->name))
		{
			float tmp_scale[3];
			float tmp_rotation[4];
			float tmp_trans[3];

			m_file.seekg(it->position);

			// read in the data
			for (int i = 0; i < 3; i++)
				m_file.read(F2V(tmp_scale[i]), sizeof(float));

			for (int i = 0; i < 4; i++)
				m_file.read(F2V(tmp_rotation[i]), sizeof(float));

			for (int i = 0; i < 3; i++)
				m_file.read(F2V(tmp_trans[i]), sizeof(float));

			// modify the matrix
			dataDestination->m4x4Translation.scale(tmp_scale[0], tmp_scale[1], tmp_scale[2]);
			dataDestination->m4x4Translation.rotate(QQuaternion(tmp_rotation[3], tmp_rotation[0], tmp_rotation[1], tmp_rotation[2]));
			dataDestination->m4x4Translation.translate(tmp_trans[0], tmp_trans[1], tmp_trans[2]);

			dataDestination->m4x4Translation = getParentMatrix(dataDestination->parent) * dataDestination->m4x4Translation;

		}

		// geometry data
		else if (!strcmp("GEOM", it->name))
		{
			// get all GEOM subchunks
			std::list<ChunkHeader*> tmp_geomChunks;
			loadChunks(tmp_geomChunks, it->position, it->size);

			// evaluate GEOM subchunks
			analyseGeomChunks(dataDestination, tmp_geomChunks);

			// clean up GEOM subchunks
			while (!tmp_geomChunks.empty())
			{
				ChunkHeader* cur = tmp_geomChunks.front();
				tmp_geomChunks.pop_front();
				delete cur;
			}
		}
	}
}

void MshFile::analyseGeomChunks(Model * dataDestination, std::list<ChunkHeader*>& chunkList)
{
	for (auto& it : chunkList)
	{
		// segment
		if (!strcmp("SEGM", it->name))
		{
			// get all SEGM subchunks
			std::list<ChunkHeader*> tmp_segmChunks;
			loadChunks(tmp_segmChunks, it->position, it->size);

			// evaluate SEGM subchunks
			analyseSegmChunks(dataDestination, tmp_segmChunks);

			// clean up SEGM subchunk
			while (!tmp_segmChunks.empty())
			{
				ChunkHeader* cur = tmp_segmChunks.front();
				tmp_segmChunks.pop_front();
				delete cur;
			}
		}

		// cloth
		else if (!strcmp("CLTH", it->name))
		{
			// get all CLTH subchunks
			std::list<ChunkHeader*> tmp_clthChunks;
			loadChunks(tmp_clthChunks, it->position, it->size);

			// evaluate CLTH subchunks
			analyseClthChunks(dataDestination, tmp_clthChunks);

			// clean up CLTH subchunks
			while (!tmp_clthChunks.empty())
			{
				ChunkHeader* cur = tmp_clthChunks.front();
				tmp_clthChunks.pop_front();
				delete cur;
			}
		}
	}
}

void MshFile::analyseSegmChunks(Model * dataDestination, std::list<ChunkHeader*>& chunkList)
{
	Segment* new_segment = new Segment;

	for (auto& it : chunkList)
	{
		// material index
		if (!strcmp("MATI", it->name))
		{
			m_file.seekg(it->position);
			m_file.read(F2V(new_segment->textureIndex), sizeof(new_segment->textureIndex));
		}

		// position list (vertex)
		else if (!strcmp("POSL", it->name))
		{
			readVertex(new_segment, it->position);
		}

		// normals
		/*else if (!strcmp("NRML", it->name))
		{
		fsMesh.seekg(it->position);
		std::uint32_t tempSize;
		fsMesh.read(reinterpret_cast<char*>(&tempSize), sizeof(tempSize));
		// List of normals
		// long int - 4 - number of normal vectores stored in this list
		// float[3][] - 12 each - UVW vector for each vertex
		}*/

		// uv
		else if (!strcmp("UV0L", it->name))
		{
			readUV(new_segment, it->position);
		}

		// polygons (indices into vertex/uv list)
		else if (!strcmp("STRP", it->name))
		{
			// don't get null, bone, shadowMesh and hidden mesh indices
			if (m_currentType == null ||
				m_currentType == bone ||
				m_currentType == shadowMesh ||
				m_currentRenderFlag == 1)
				continue;

			// jump to the data section and read the size;
			std::uint32_t tmp_size;
			m_file.seekg(it->position);
			m_file.read(F2V(tmp_size), sizeof(tmp_size));

			int highBitCount(0);
			QVector<GLuint> tmp_buffer;

			for (unsigned int i = 0; i < tmp_size; i++)
			{
				// ReadData
				std::uint16_t tmp_value;
				m_file.read(F2V(tmp_value), sizeof(tmp_value));

				// Check if highbit is set
				if (tmp_value >> 15)
				{
					highBitCount++;
					// remove the high bit, to get the actually value
					tmp_value = (std::uint16_t(tmp_value << 1) >> 1);
				}

				// save data
				tmp_buffer.push_back((GLuint)tmp_value);

				// if the last 2 highBits are set, it was a new poly
				if (highBitCount == 2)
				{
					// reset highBitCount
					highBitCount = 0;

					if (tmp_buffer.size() == 5)
					{
						for (size_t i = 0; i < 3; i++)
							new_segment->indices.push_back(tmp_buffer.takeFirst());
					}
					else if (tmp_buffer.size() > 5)
					{
						unsigned int tmp_multiPolySize = tmp_buffer.size() - 2;
						// for every triangle of the multi polygon..
						for (unsigned int tri = 0; tri < tmp_multiPolySize - 2; tri++)
							// ..calculate the edge indices
							for (int triEdge = 0; triEdge < 3; triEdge++)
								new_segment->indices.push_back((GLuint)tmp_buffer[(tri + triEdge - ((tri % 2) * (triEdge - 1) * 2))]);
					}

				}	// if 2 high bits are set

			}	// for all values

			// save the last polygon (no 2 high bit followed)
			if (tmp_buffer.size() == 3)
			{
				for (size_t i = 0; i < 3; i++)
					new_segment->indices.push_back(tmp_buffer.takeFirst());
			}
			else if (tmp_buffer.size() > 3)
			{
				unsigned int tmp_multiPolySize = tmp_buffer.size();
				// for every triangle of the multi polygon..
				for (unsigned int tri = 0; tri < tmp_multiPolySize - 2; tri++)
					// ..calculate the edge indices
					for (int triEdge = 0; triEdge < 3; triEdge++)
						new_segment->indices.push_back((GLuint)tmp_buffer[(tri + triEdge - ((tri % 2) * (triEdge - 1) * 2))]);
			}
		}
	}

	dataDestination->segmList.push_back(new_segment);
}

void MshFile::analyseClthChunks(Model * dataDestination, std::list<ChunkHeader*>& chunkList)
{
	Segment* new_segment = new Segment;

	for (auto& it : chunkList)
	{
		// texture name
		if (!strcmp("CTEX", it->name))
		{
			// read the texture name
			m_file.seekg(it->position);
			char* buffer = new char[it->size + 1];
			*buffer = { 0 };
			m_file.read(buffer, it->size);

			// search if it is already known
			bool tmp_found(false);
			for (unsigned int i = 0; i < m_textureNames->size(); i++)
			{
				if (!strcmp(buffer, m_textureNames->at(i).c_str()))
				{
					// if found, save the index and stop searching
					new_segment->textureIndex = i;
					tmp_found = true;
					break;
				}
			}

			// if it was not found add the texturename to the list
			if (!tmp_found)
			{
				m_textureNames->push_back(std::string(buffer));
				new_segment->textureIndex = m_textureNames->size() - 1;
			}

			delete[] buffer;
		}

		// position list (vertex)
		else if (!strcmp("CPOS", it->name))
		{
			readVertex(new_segment, it->position);
		}

		// uv 
		else if (!strcmp("CUV0", it->name))
		{
			readUV(new_segment, it->position);
		}

		// triangles (indices into vertex/uv list)
		else if (!strcmp("CMSH", it->name))
		{
			// jump to the data section and read the size;
			std::uint32_t tmp_size;
			m_file.seekg(it->position);
			m_file.read(F2V(tmp_size), sizeof(tmp_size));

			// for every triangle..
			for (unsigned int i = 0; i < tmp_size * 3; i++)
			{
				std::uint32_t tmp_value;
				m_file.read(F2V(tmp_value), sizeof(std::uint32_t));

				new_segment->indices.push_back((GLuint)tmp_value);
			}
		}
	}

	dataDestination->segmList.push_back(new_segment);
}

void MshFile::readVertex(Segment * dataDestination, std::streampos position)
{
	std::uint32_t tmp_size;
	m_file.seekg(position);
	m_file.read(F2V(tmp_size), sizeof(tmp_size));

	for (unsigned int i = 0; i < tmp_size; i++)
	{
		float tmp[3];
		for (unsigned int j = 0; j < 3; j++)
			m_file.read(F2V(tmp[j]), sizeof(float));
		
		VertexData new_data;
		new_data.position = QVector3D(tmp[0], tmp[1], tmp[2]);

		dataDestination->vertices.push_back(new_data);
	}
}

void MshFile::readUV(Segment * dataDestination, std::streampos position)
{
	std::uint32_t tmp_size;
	m_file.seekg(position);
	m_file.read(F2V(tmp_size), sizeof(tmp_size));

	if (tmp_size < dataDestination->vertices.size())
	{
		//TODO: warning
		std::cout << "WARNING: too less UVs " << tmp_size << " < " << dataDestination->vertices.size() << std::endl;

		//TODO: fill backward with default UVs
	}
	else if (tmp_size > dataDestination->vertices.size())
	{
		//TODO: warning
		std::cout << "WARNING: too many UVs " << tmp_size << " > " << dataDestination->vertices.size() << std::endl;
		tmp_size = dataDestination->vertices.size();
	}

	for (unsigned int i = 0; i < tmp_size; i++)
	{
		float tmp[2];
		for (unsigned int j = 0; j < 2; j++)
			m_file.read(F2V(dataDestination->vertices[i].texCoord[j]), sizeof(float));
	}
}

QMatrix4x4 MshFile::getParentMatrix(std::string parent) const
{
	QMatrix4x4 matrix;

	for (auto& it : *m_models)
	{
		if (!strcmp(parent.c_str(), it->name.c_str()))
		{
			//TODO: the other way around??
			matrix = getParentMatrix(it->parent) * it->m4x4Translation;
			break;
		}
	}

	return matrix;
}