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

Copyright (c) 2006-2012, 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
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* 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,
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---------------------------------------------------------------------------
*/

#include "AssimpPCH.h"
#ifndef ASSIMP_BUILD_NO_MD2_IMPORTER

/** @file Implementation of the MD2 importer class */
#include "MD2Loader.h"
#include "ByteSwap.h"
#include "MD2NormalTable.h" // shouldn't be included by other units

using namespace Assimp;
using namespace Assimp::MD2;


// helper macro to determine the size of an array
#if (!defined ARRAYSIZE)
#	define ARRAYSIZE(_array) (int(sizeof(_array) / sizeof(_array[0])))
#endif 

// ------------------------------------------------------------------------------------------------
// Helper function to lookup a normal in Quake 2's precalculated table
void MD2::LookupNormalIndex(uint8_t iNormalIndex,aiVector3D& vOut)
{
	// make sure the normal index has a valid value
	if (iNormalIndex >= ARRAYSIZE(g_avNormals))	{
		DefaultLogger::get()->warn("Index overflow in Quake II normal vector list");
		iNormalIndex = ARRAYSIZE(g_avNormals) - 1;
	}
	vOut = *((const aiVector3D*)(&g_avNormals[iNormalIndex]));
}


// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
MD2Importer::MD2Importer()
{}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well 
MD2Importer::~MD2Importer()
{}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file. 
bool MD2Importer::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool checkSig) const
{
	const std::string extension = GetExtension(pFile);
	if (extension == "md2")
		return true;

	// if check for extension is not enough, check for the magic tokens 
	if (!extension.length() || checkSig) {
		uint32_t tokens[1]; 
		tokens[0] = AI_MD2_MAGIC_NUMBER_LE;
		return CheckMagicToken(pIOHandler,pFile,tokens,1);
	}
	return false;
}

// ------------------------------------------------------------------------------------------------
// Get a list of all extensions supported by this loader
void MD2Importer::GetExtensionList(std::set<std::string>& extensions)
{
	extensions.insert("md2");
}

// ------------------------------------------------------------------------------------------------
// Setup configuration properties
void MD2Importer::SetupProperties(const Importer* pImp)
{
	// The 
	// AI_CONFIG_IMPORT_MD2_KEYFRAME option overrides the
	// AI_CONFIG_IMPORT_GLOBAL_KEYFRAME option.
	configFrameID = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_MD2_KEYFRAME,-1);
	if(static_cast<unsigned int>(-1) == configFrameID){
		configFrameID = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_GLOBAL_KEYFRAME,0);
	}
}
// ------------------------------------------------------------------------------------------------
// Validate the file header
void MD2Importer::ValidateHeader( )
{
	// check magic number
	if (m_pcHeader->magic != AI_MD2_MAGIC_NUMBER_BE &&
		m_pcHeader->magic != AI_MD2_MAGIC_NUMBER_LE)
	{
		char szBuffer[5];
		szBuffer[0] = ((char*)&m_pcHeader->magic)[0];
		szBuffer[1] = ((char*)&m_pcHeader->magic)[1];
		szBuffer[2] = ((char*)&m_pcHeader->magic)[2];
		szBuffer[3] = ((char*)&m_pcHeader->magic)[3];
		szBuffer[4] = '\0';

		throw DeadlyImportError("Invalid MD2 magic word: should be IDP2, the "
			"magic word found is " + std::string(szBuffer));
	}

	// check file format version
	if (m_pcHeader->version != 8)
		DefaultLogger::get()->warn( "Unsupported md2 file version. Continuing happily ...");

	// check some values whether they are valid
	if (0 == m_pcHeader->numFrames)
		throw DeadlyImportError( "Invalid md2 file: NUM_FRAMES is 0");

	if (m_pcHeader->offsetEnd > (uint32_t)fileSize)
		throw DeadlyImportError( "Invalid md2 file: File is too small");

	if (m_pcHeader->offsetSkins		+ m_pcHeader->numSkins * sizeof (MD2::Skin)			>= fileSize ||
		m_pcHeader->offsetTexCoords	+ m_pcHeader->numTexCoords * sizeof (MD2::TexCoord)	>= fileSize ||
		m_pcHeader->offsetTriangles	+ m_pcHeader->numTriangles * sizeof (MD2::Triangle)	>= fileSize ||
		m_pcHeader->offsetFrames		+ m_pcHeader->numFrames * sizeof (MD2::Frame)			>= fileSize ||
		m_pcHeader->offsetEnd			> fileSize)
	{
		throw DeadlyImportError("Invalid MD2 header: some offsets are outside the file");
	}

	if (m_pcHeader->numSkins > AI_MD2_MAX_SKINS)
		DefaultLogger::get()->warn("The model contains more skins than Quake 2 supports");
	if ( m_pcHeader->numFrames > AI_MD2_MAX_FRAMES)
		DefaultLogger::get()->warn("The model contains more frames than Quake 2 supports");
	if (m_pcHeader->numVertices > AI_MD2_MAX_VERTS)
		DefaultLogger::get()->warn("The model contains more vertices than Quake 2 supports");

	if (m_pcHeader->numFrames <= configFrameID )
		throw DeadlyImportError("The requested frame is not existing the file");
}

// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure. 
void MD2Importer::InternReadFile( const std::string& pFile, 
	aiScene* pScene, IOSystem* pIOHandler)
{
	boost::scoped_ptr<IOStream> file( pIOHandler->Open( pFile));

	// Check whether we can read from the file
	if( file.get() == NULL)
		throw DeadlyImportError( "Failed to open MD2 file " + pFile + "");

	// check whether the md3 file is large enough to contain
	// at least the file header
	fileSize = (unsigned int)file->FileSize();
	if( fileSize < sizeof(MD2::Header))
		throw DeadlyImportError( "MD2 File is too small");

	std::vector<uint8_t> mBuffer2(fileSize);
	file->Read(&mBuffer2[0], 1, fileSize);
	mBuffer = &mBuffer2[0];


	m_pcHeader = (BE_NCONST MD2::Header*)mBuffer;

#ifdef AI_BUILD_BIG_ENDIAN

	ByteSwap::Swap4(&m_pcHeader->frameSize);
	ByteSwap::Swap4(&m_pcHeader->magic);
	ByteSwap::Swap4(&m_pcHeader->numFrames);
	ByteSwap::Swap4(&m_pcHeader->numGlCommands);
	ByteSwap::Swap4(&m_pcHeader->numSkins);
	ByteSwap::Swap4(&m_pcHeader->numTexCoords);
	ByteSwap::Swap4(&m_pcHeader->numTriangles);
	ByteSwap::Swap4(&m_pcHeader->numVertices);
	ByteSwap::Swap4(&m_pcHeader->offsetEnd);
	ByteSwap::Swap4(&m_pcHeader->offsetFrames);
	ByteSwap::Swap4(&m_pcHeader->offsetGlCommands);
	ByteSwap::Swap4(&m_pcHeader->offsetSkins);
	ByteSwap::Swap4(&m_pcHeader->offsetTexCoords);
	ByteSwap::Swap4(&m_pcHeader->offsetTriangles);
	ByteSwap::Swap4(&m_pcHeader->skinHeight);
	ByteSwap::Swap4(&m_pcHeader->skinWidth);
	ByteSwap::Swap4(&m_pcHeader->version);

#endif

	ValidateHeader();

	// there won't be more than one mesh inside the file
	pScene->mNumMaterials = 1;
	pScene->mRootNode = new aiNode();
	pScene->mRootNode->mNumMeshes = 1;
	pScene->mRootNode->mMeshes = new unsigned int[1];
	pScene->mRootNode->mMeshes[0] = 0;
	pScene->mMaterials = new aiMaterial*[1];
	pScene->mMaterials[0] = new aiMaterial();
	pScene->mNumMeshes = 1;
	pScene->mMeshes = new aiMesh*[1];

	aiMesh* pcMesh = pScene->mMeshes[0] = new aiMesh();
	pcMesh->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;

	// navigate to the begin of the frame data
	BE_NCONST MD2::Frame* pcFrame = (BE_NCONST MD2::Frame*) ((uint8_t*)
		m_pcHeader + m_pcHeader->offsetFrames);

	pcFrame += configFrameID;

	// navigate to the begin of the triangle data
	MD2::Triangle* pcTriangles = (MD2::Triangle*) ((uint8_t*)
		m_pcHeader + m_pcHeader->offsetTriangles);

	// navigate to the begin of the tex coords data
	BE_NCONST MD2::TexCoord* pcTexCoords = (BE_NCONST MD2::TexCoord*) ((uint8_t*)
		m_pcHeader + m_pcHeader->offsetTexCoords);

	// navigate to the begin of the vertex data
	BE_NCONST MD2::Vertex* pcVerts = (BE_NCONST MD2::Vertex*) (pcFrame->vertices);

#ifdef AI_BUILD_BIG_ENDIAN
	for (uint32_t i = 0; i< m_pcHeader->numTriangles; ++i)
	{
		for (unsigned int p = 0; p < 3;++p)
		{
			ByteSwap::Swap2(& pcTriangles[i].textureIndices[p]);
			ByteSwap::Swap2(& pcTriangles[i].vertexIndices[p]);
		}
	}
	for (uint32_t i = 0; i < m_pcHeader->offsetTexCoords;++i)
	{
		ByteSwap::Swap2(& pcTexCoords[i].s);
		ByteSwap::Swap2(& pcTexCoords[i].t);
	}
	ByteSwap::Swap4( & pcFrame->scale[0] );
	ByteSwap::Swap4( & pcFrame->scale[1] );
	ByteSwap::Swap4( & pcFrame->scale[2] );
	ByteSwap::Swap4( & pcFrame->translate[0] );
	ByteSwap::Swap4( & pcFrame->translate[1] );
	ByteSwap::Swap4( & pcFrame->translate[2] );
#endif

	pcMesh->mNumFaces = m_pcHeader->numTriangles;
	pcMesh->mFaces = new aiFace[m_pcHeader->numTriangles];

	// allocate output storage
	pcMesh->mNumVertices = (unsigned int)pcMesh->mNumFaces*3;
	pcMesh->mVertices = new aiVector3D[pcMesh->mNumVertices];
	pcMesh->mNormals = new aiVector3D[pcMesh->mNumVertices];

	// Not sure whether there are MD2 files without texture coordinates
	// NOTE: texture coordinates can be there without a texture,
	// but a texture can't be there without a valid UV channel
	aiMaterial* pcHelper = (aiMaterial*)pScene->mMaterials[0];
	const int iMode = (int)aiShadingMode_Gouraud;
	pcHelper->AddProperty<int>(&iMode, 1, AI_MATKEY_SHADING_MODEL);

	if (m_pcHeader->numTexCoords && m_pcHeader->numSkins)
	{
		// navigate to the first texture associated with the mesh
		const MD2::Skin* pcSkins = (const MD2::Skin*) ((unsigned char*)m_pcHeader + 
			m_pcHeader->offsetSkins);

		aiColor3D clr;
		clr.b = clr.g = clr.r = 1.0f;
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_DIFFUSE);
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_SPECULAR);

		clr.b = clr.g = clr.r = 0.05f;
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_AMBIENT);

		if (pcSkins->name[0])
		{
			aiString szString;
			const size_t iLen = ::strlen(pcSkins->name);
			::memcpy(szString.data,pcSkins->name,iLen);
			szString.data[iLen] = '\0';
			szString.length = iLen;

			pcHelper->AddProperty(&szString,AI_MATKEY_TEXTURE_DIFFUSE(0));
		}
		else{
			DefaultLogger::get()->warn("Texture file name has zero length. It will be skipped.");
		}
	}
	else	{
		// apply a default material
		aiColor3D clr;
		clr.b = clr.g = clr.r = 0.6f;
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_DIFFUSE);
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_SPECULAR);

		clr.b = clr.g = clr.r = 0.05f;
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_AMBIENT);

		aiString szName;
		szName.Set(AI_DEFAULT_MATERIAL_NAME);
		pcHelper->AddProperty(&szName,AI_MATKEY_NAME);

		aiString sz;

		// TODO: Try to guess the name of the texture file from the model file name

		sz.Set("$texture_dummy.bmp");
		pcHelper->AddProperty(&sz,AI_MATKEY_TEXTURE_DIFFUSE(0));
	}


	// now read all triangles of the first frame, apply scaling and translation
	unsigned int iCurrent = 0;

	float fDivisorU = 1.0f,fDivisorV = 1.0f;
	if (m_pcHeader->numTexCoords)	{
		// allocate storage for texture coordinates, too
		pcMesh->mTextureCoords[0] = new aiVector3D[pcMesh->mNumVertices];
		pcMesh->mNumUVComponents[0] = 2;

		// check whether the skin width or height are zero (this would
		// cause a division through zero)
		if (!m_pcHeader->skinWidth)	{
			DefaultLogger::get()->error("MD2: No valid skin width given");
		}
		else fDivisorU = (float)m_pcHeader->skinWidth;
		if (!m_pcHeader->skinHeight){
			DefaultLogger::get()->error("MD2: No valid skin height given");
		}
		else fDivisorV = (float)m_pcHeader->skinHeight;
	}

	for (unsigned int i = 0; i < (unsigned int)m_pcHeader->numTriangles;++i)	{
		// Allocate the face
		pScene->mMeshes[0]->mFaces[i].mIndices = new unsigned int[3];
		pScene->mMeshes[0]->mFaces[i].mNumIndices = 3;

		// copy texture coordinates
		// check whether they are different from the previous value at this index.
		// In this case, create a full separate set of vertices/normals/texcoords
		for (unsigned int c = 0; c < 3;++c,++iCurrent)	{

			// validate vertex indices
			register unsigned int iIndex = (unsigned int)pcTriangles[i].vertexIndices[c];
			if (iIndex >= m_pcHeader->numVertices)	{
				DefaultLogger::get()->error("MD2: Vertex index is outside the allowed range");
				iIndex = m_pcHeader->numVertices-1;
			}

			// read x,y, and z component of the vertex
			aiVector3D& vec = pcMesh->mVertices[iCurrent];

			vec.x = (float)pcVerts[iIndex].vertex[0] * pcFrame->scale[0];
			vec.x += pcFrame->translate[0];

			vec.y = (float)pcVerts[iIndex].vertex[1] * pcFrame->scale[1];
			vec.y += pcFrame->translate[1];

			vec.z = (float)pcVerts[iIndex].vertex[2] * pcFrame->scale[2];
			vec.z += pcFrame->translate[2];

			// read the normal vector from the precalculated normal table
			aiVector3D& vNormal = pcMesh->mNormals[iCurrent];
			LookupNormalIndex(pcVerts[iIndex].lightNormalIndex,vNormal);

			// flip z and y to become right-handed
			std::swap((float&)vNormal.z,(float&)vNormal.y);
			std::swap((float&)vec.z,(float&)vec.y);

			if (m_pcHeader->numTexCoords)	{
				// validate texture coordinates
				iIndex = pcTriangles[i].textureIndices[c];
				if (iIndex >= m_pcHeader->numTexCoords)	{
					DefaultLogger::get()->error("MD2: UV index is outside the allowed range");
					iIndex = m_pcHeader->numTexCoords-1;
				}

				aiVector3D& pcOut = pcMesh->mTextureCoords[0][iCurrent];

				// the texture coordinates are absolute values but we
				// need relative values between 0 and 1
				pcOut.x = pcTexCoords[iIndex].s / fDivisorU;
				pcOut.y = 1.f-pcTexCoords[iIndex].t / fDivisorV;
			}
			pScene->mMeshes[0]->mFaces[i].mIndices[c] = iCurrent;
		}
	}
}

#endif // !! ASSIMP_BUILD_NO_MD2_IMPORTER