#include "Object.h"
#include <iostream>
#define PI (4.0*atan(1.0))


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

Object::Object(const char* path)
{
	// open file
	fsMesh.open(path, std::ios::in | std::ios::binary);

	if (!fsMesh.is_open())
		throw std::invalid_argument(std::string("file not found: ") += path);

	// jump to file size information
	fsMesh.seekg(4);

	std::uint32_t tempFileSize;
	std::list<ChunkHeader*> tempMainChunks;

	// get all chunks under HEDR
	fsMesh.read(reinterpret_cast<char*>(&tempFileSize), sizeof(tempFileSize));
	loadChunks(tempMainChunks, fsMesh.tellg(), tempFileSize);

	// evaluate HEDR subchunks (= find MSH2)
	for (std::list<ChunkHeader*>::iterator it = tempMainChunks.begin(); it != tempMainChunks.end(); it++)
	{
		if (!strcmp("MSH2", (*it)->name))
		{
			// get all subchunks
			std::list<ChunkHeader*> tempMsh2Chunks;
			loadChunks(tempMsh2Chunks, (*it)->position, (*it)->size);

			// evaluate MSH2 subchunks
			analyseMsh2Chunks(tempMsh2Chunks);

			// clean up
			while (!tempMsh2Chunks.empty())
			{
				ChunkHeader* tempCursor = tempMsh2Chunks.front();
				tempMsh2Chunks.pop_front();
				delete tempCursor;
			}
			continue;
		}
	}

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

	// close file
	fsMesh.close();
}

Object::~Object()
{
	// clear texture list
	vTextures.clear();

	// clear Model list (don't delete the elements)
	vModls.clear();
}


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

void Object::setModlDefault(Modl * model)
{
	model->name = "";
	model->parent = "";
	model->type = null;
	model->renderFlags = -1;
	model->m4x4Translation = glm::mat4(1.0f);
	model->texture = "";
	model->vertex = NULL;
	model->uv = NULL;
	model->mesh = NULL;
	model->meshSize = 0;
}

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

	do
	{
		ChunkHeader* tempHeader = new ChunkHeader();

		fsMesh.read(reinterpret_cast<char*>(&tempHeader->name[0]), sizeof(tempHeader->name) - 1);
		fsMesh.read(reinterpret_cast<char*>(&tempHeader->size), sizeof(tempHeader->size));
		tempHeader->position = fsMesh.tellg();

		destination.push_back(tempHeader);

		fsMesh.seekg(tempHeader->size, std::ios_base::cur);

		// reached end
		if (fsMesh.tellg() - start == end)
			break;

		// error. Maybe the size information is corrupted
		if (!fsMesh.good())
		{
			std::cout << "WARNING: corrupted file. Trying to continue" << std::endl;
			fsMesh.clear();
			break;
		}

	} while (true);
}

void Object::analyseMsh2Chunks(std::list<ChunkHeader*>& chunkList)
{
	for (std::list<ChunkHeader*>::iterator it = chunkList.begin(); it != chunkList.end(); it++)
	{
		if (!strcmp("MATL", (*it)->name))
		{
			// "useless" information how many MATD follow
			fsMesh.seekg((*it)->position);
			std::uint32_t tempMatdCount;
			fsMesh.read(reinterpret_cast<char*>(&tempMatdCount), sizeof(std::uint32_t));

			// get all MATD from MATL list
			std::list<ChunkHeader*> tempMatlChunks;
			loadChunks(tempMatlChunks, fsMesh.tellg(), (*it)->size - 4);

			// evaluate MATL subchunks
			for (std::list<ChunkHeader*>::iterator it = tempMatlChunks.begin(); it != tempMatlChunks.end(); it++)
			{
				// This shouldn't be anything else than MATD
				if (!strcmp("MATD", (*it)->name))
				{
					// get all subchunks from MATD
					std::list<ChunkHeader*> tempMatdChunks;
					loadChunks(tempMatdChunks, (*it)->position, (*it)->size);

					// analyse MATD subchunks
					analyseMatdChunks(tempMatdChunks);

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

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

			continue;
		}

		if (!strcmp("MODL", (*it)->name))
		{
			Modl* tempModl = new Modl;
			setModlDefault(tempModl);

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

			// evaluate MODL subchunks
			analyseModlChunks(tempModl, tempChunks);

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

			// save Model data
			vModls.push_back(tempModl);

			continue;
		}
	}
}

void Object::analyseMatdChunks(std::list<ChunkHeader*>& chunkList)
{
	for (std::list<ChunkHeader*>::iterator it = chunkList.begin(); it != chunkList.end(); it++)
	{
		//TX1D, TX2D, TX3D
		if (!strcmp("TX0D", (*it)->name))
		{
			fsMesh.seekg((*it)->position);
			char* buffer = new char[(*it)->size + 1];
			*buffer = { 0 };
			fsMesh.read(buffer, (*it)->size);
			vTextures.push_back(buffer);
			delete buffer;
			continue;
		}
	}
}

void Object::analyseModlChunks(Modl* dataDestination, std::list<ChunkHeader*>& chunkList)
{
	for (std::list<ChunkHeader*>::iterator it = chunkList.begin(); it != chunkList.end(); it++)
	{
		if (!strcmp("MTYP", (*it)->name))
		{
			fsMesh.seekg((*it)->position);
			std::uint32_t tempType;
			fsMesh.read(reinterpret_cast<char*>(&tempType), sizeof(tempType));
			dataDestination->type = (Mtyp)tempType;
			continue;
		}

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

		if (!strcmp("NAME", (*it)->name))
		{
			fsMesh.seekg((*it)->position);
			char* buffer = new char[(*it)->size];
			*buffer = { 0 };
			fsMesh.read(buffer, (*it)->size);
			dataDestination->name = buffer;
			delete buffer;
			continue;
		}

		if (!strcmp("FLGS", (*it)->name))
		{
			fsMesh.seekg((*it)->position);
			fsMesh.read(reinterpret_cast<char*>(&dataDestination->renderFlags), sizeof(dataDestination->renderFlags));
			continue;
		}

		if (!strcmp("TRAN", (*it)->name))
		{
			float tempScale[3];
			float tempRotation[4];
			float tempTrans[3];

			fsMesh.seekg((*it)->position);

			fsMesh.read(reinterpret_cast<char*>(&tempScale[0]), sizeof(float));
			fsMesh.read(reinterpret_cast<char*>(&tempScale[1]), sizeof(float));
			fsMesh.read(reinterpret_cast<char*>(&tempScale[2]), sizeof(float));

			fsMesh.read(reinterpret_cast<char*>(&tempRotation[0]), sizeof(float));
			fsMesh.read(reinterpret_cast<char*>(&tempRotation[1]), sizeof(float));
			fsMesh.read(reinterpret_cast<char*>(&tempRotation[2]), sizeof(float));
			fsMesh.read(reinterpret_cast<char*>(&tempRotation[3]), sizeof(float));

			//calculate x,y,z rotation
			tempRotation[0] = atan2(2 * (tempRotation[0] * tempRotation[1] + tempRotation[2] * tempRotation[3]),
									1 - 2 * (pow(tempRotation[1], 2) + pow(tempRotation[2], 2)));
			tempRotation[1] = asin(2 * (tempRotation[0] * tempRotation[2] - tempRotation[3] * tempRotation[1]));
			tempRotation[2] = atan2(2 * (tempRotation[0] * tempRotation[3] + tempRotation[1] * tempRotation[2]),
									1 - 2 * (pow(tempRotation[2], 2) + pow(tempRotation[3], 2))) - PI;

			fsMesh.read(reinterpret_cast<char*>(&tempTrans[0]), sizeof(float));
			fsMesh.read(reinterpret_cast<char*>(&tempTrans[1]), sizeof(float));
			fsMesh.read(reinterpret_cast<char*>(&tempTrans[2]), sizeof(float));

			dataDestination->m4x4Translation = glm::scale(
				dataDestination->m4x4Translation,
				glm::vec3(tempScale[0], tempScale[1], tempScale[2])
			);

			dataDestination->m4x4Translation = glm::translate(
				dataDestination->m4x4Translation,
				glm::vec3(tempTrans[0], tempTrans[1], tempTrans[2])
			);

			dataDestination->m4x4Translation = glm::rotate(
				dataDestination->m4x4Translation,
				tempRotation[0],
				glm::vec3(1, 0, 0)
			);

			dataDestination->m4x4Translation = glm::rotate(
				dataDestination->m4x4Translation,
				tempRotation[1],
				glm::vec3(0, 1, 0)
			);

			dataDestination->m4x4Translation = glm::rotate(
				dataDestination->m4x4Translation,
				tempRotation[2],
				glm::vec3(0, 0, 1)
			);

			continue;
		}

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

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

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

			continue;
		}
	}
}

void Object::analyseGeomChunks(Modl * dataDestination, std::list<ChunkHeader*>& chunkList)
{
	for (std::list<ChunkHeader*>::iterator it = chunkList.begin(); it != chunkList.end(); it++)
	{
		if (!strcmp("SEGM", (*it)->name))
		{
			// get all subchunks
			std::list<ChunkHeader*> tempSegmChunks;
			loadChunks(tempSegmChunks, (*it)->position, (*it)->size);

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

			// clean up
			while (!tempSegmChunks.empty())
			{
				ChunkHeader* tempCursor = tempSegmChunks.front();
				tempSegmChunks.pop_front();
				delete tempCursor;
			}
			continue;
		}
		
		if (!strcmp("CLTH", (*it)->name))
		{
			// get all subchunks
			std::list<ChunkHeader*> tempClthChunks;
			loadChunks(tempClthChunks, (*it)->position, (*it)->size);

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

			// clean up
			while (!tempClthChunks.empty())
			{
				ChunkHeader* tempCursor = tempClthChunks.front();
				tempClthChunks.pop_front();
				delete tempCursor;
			}
			continue;
		}
	}
}

void Object::analyseSegmChunks(Modl * dataDestination, std::list<ChunkHeader*>& chunkList)
{
	for (std::list<ChunkHeader*>::iterator it = chunkList.begin(); it != chunkList.end(); it++)
	{
		/*if (!strcmp("SHDW", (*it)->name))
		{
			fsMesh.seekg((*it)->position);
			/* shadow mesh geometry

			long int - 4 - number of vertex positions
			float[3][] - 12 each - vertex positions (XYZ)
			long int - 4 - number of edges
			short int[4][] - 8 each - edge the following 4 entries from one edge
			> short int - 2 - vertex index of this edge, referes to the vertex list
			> short int - 2 - Reference into an edge. Defines the target vertex (the local edge vertex of the referenced edge) to which the edge should be dran from the local vertex
			> short int - 2 - Second reference into an edge. In all example .msh files I've seen this always refers to the same vertex as the first edge reference
			> short int - 2 - MAX_VALUE of short integers (65535). Indicates the end of this edge
			* /
			continue;
		}*/

		if (!strcmp("MATI", (*it)->name))
		{
			fsMesh.seekg((*it)->position);
			std::uint32_t tempIndex;
			fsMesh.read(reinterpret_cast<char*>(&tempIndex), sizeof(tempIndex));
			if (vTextures.size() <= tempIndex)
			{
				std::cout << "warning texture index <" << tempIndex << "> unknown" << std::endl;
				dataDestination->texture = "";
				continue;
			}
			dataDestination->texture = vTextures[tempIndex];
			continue;
		}

		if (!strcmp("POSL", (*it)->name))
		{
			readVertex(dataDestination, (*it)->position);
			continue;
		}

		/*if (!strcmp("NRML", (*it)->name))
		{
			fsMesh.seekg((*it)->position);
			// List of normals
			// long int - 4 - number of normal vectores stored in this list
			// float[3][] - 12 each - UVW vector for each vertex
			continue;
		}*/

		if (!strcmp("UV0L", (*it)->name))
		{
			readUV(dataDestination, (*it)->position);
			continue;
		}

		if (!strcmp("STRP", (*it)->name))
		{
			fsMesh.seekg((*it)->position);

			fsMesh.seekg((*it)->position);
			fsMesh.read(reinterpret_cast<char*>(&dataDestination->meshSize), sizeof(dataDestination->meshSize));

			dataDestination->mesh = new std::uint32_t[dataDestination->meshSize];

			for (unsigned int i = 0; i < dataDestination->meshSize; i += 3)
			{
				std::uint16_t tempValue[3];
				fsMesh.read(reinterpret_cast<char*>(&tempValue[0]), sizeof(std::uint16_t));
				fsMesh.read(reinterpret_cast<char*>(&tempValue[1]), sizeof(std::uint16_t));
				fsMesh.read(reinterpret_cast<char*>(&tempValue[2]), sizeof(std::uint16_t));

				if (!(tempValue[0] >> 15 && tempValue[1] >> 15 && !(tempValue[2] >> 15)))
					throw std::invalid_argument("invalid file. go and triangulate!");

				tempValue[0] = (std::uint16_t(tempValue[0] << 1) >> 1);
				tempValue[1] = (std::uint16_t(tempValue[1] << 1) >> 1);

				dataDestination->mesh[i] = (std::uint32_t)tempValue[0];
				dataDestination->mesh[i + 1] = (std::uint32_t)tempValue[1];
				dataDestination->mesh[i + 2] = (std::uint32_t)tempValue[2];
			}

			continue;
		}
	}
}

void Object::analyseClthChunks(Modl * dataDestination, std::list<ChunkHeader*>& chunkList)
{
	for (std::list<ChunkHeader*>::iterator it = chunkList.begin(); it != chunkList.end(); it++)
	{
		if (!strcmp("CTEX", (*it)->name))
		{
			fsMesh.seekg((*it)->position);
			char* buffer = new char[(*it)->size];
			*buffer = { 0 };
			fsMesh.read(buffer, (*it)->size);
			dataDestination->texture = buffer;
			delete buffer;
			continue;
		}

		if (!strcmp("CPOS", (*it)->name))
		{
			readVertex(dataDestination, (*it)->position);
			continue;
		}

		if (!strcmp("CUV0", (*it)->name))
		{
			readUV(dataDestination, (*it)->position);
			continue;
		}

		if (!strcmp("CMSH", (*it)->name))
		{
			fsMesh.seekg((*it)->position);
			fsMesh.read(reinterpret_cast<char*>(&dataDestination->meshSize), sizeof(dataDestination->meshSize));

			dataDestination->mesh = new std::uint32_t[dataDestination->meshSize * 3];

			for (unsigned int i = 0; i < dataDestination->meshSize; i += 3)
			{
				fsMesh.read(reinterpret_cast<char*>(&dataDestination->mesh[i]), sizeof(std::uint32_t));
				fsMesh.read(reinterpret_cast<char*>(&dataDestination->mesh[i + 1]), sizeof(std::uint32_t));
				fsMesh.read(reinterpret_cast<char*>(&dataDestination->mesh[i + 2]), sizeof(std::uint32_t));
			}
			continue;
		}
	}
}

void Object::readVertex(Modl* dataDestination, std::streampos position)
{
	std::uint32_t tempSize;
	fsMesh.seekg(position);
	fsMesh.read(reinterpret_cast<char*>(&tempSize), sizeof(tempSize));

	dataDestination->vertex = new float[tempSize * 3];

	for (unsigned int i = 0; i < tempSize * 3; i++)
		fsMesh.read(reinterpret_cast<char*>(&dataDestination->vertex[i]), sizeof(float));
}

void Object::readUV(Modl* dataDestination, std::streampos position)
{
	std::uint32_t tempSize;
	fsMesh.seekg(position);
	fsMesh.read(reinterpret_cast<char*>(&tempSize), sizeof(tempSize));

	dataDestination->uv = new float[tempSize * 2];

	for (unsigned int i = 0; i < tempSize * 2; i++)
		fsMesh.read(reinterpret_cast<char*>(&dataDestination->uv[i]), sizeof(float));
}


/////////////////////////////////////////////////////////////////////////
// public getter

std::vector<Modl*> Object::getModels() const
{
	return vModls;
}


/////////////////////////////////////////////////////////////////////////
// public functions