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

Copyright (c) 2006-2012, assimp team

All rights reserved.

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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
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  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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---------------------------------------------------------------------------
*/

/** @file Implementation of the IrrMesh importer class */

#include "AssimpPCH.h"

#include "IRRMeshLoader.h"
#include "ParsingUtils.h"
#include "fast_atof.h"

using namespace Assimp;
using namespace irr;
using namespace irr::io;

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

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

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file. 
bool IRRMeshImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool checkSig) const
{
	/* NOTE: A simple check for the file extension is not enough
	 * here. Irrmesh and irr are easy, but xml is too generic
	 * and could be collada, too. So we need to open the file and
	 * search for typical tokens.
	 */
	const std::string extension = GetExtension(pFile);

	if (extension == "irrmesh")return true;
	else if (extension == "xml" || checkSig)
	{
		/*  If CanRead() is called to check whether the loader
		 *  supports a specific file extension in general we
		 *  must return true here.
		 */
		if (!pIOHandler)return true;
		const char* tokens[] = {"irrmesh"};
		return SearchFileHeaderForToken(pIOHandler,pFile,tokens,1);
	}
	return false;
}

// ------------------------------------------------------------------------------------------------
// Get a list of all file extensions which are handled by this class
void IRRMeshImporter::GetExtensionList(std::set<std::string>& extensions)
{
	extensions.insert("xml");
	extensions.insert("irrmesh");
}

// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure. 
void IRRMeshImporter::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 IRRMESH file " + pFile + "");

	// Construct the irrXML parser
	CIrrXML_IOStreamReader st(file.get());
	reader = createIrrXMLReader((IFileReadCallBack*) &st);

	// final data
	std::vector<aiMaterial*> materials;
	std::vector<aiMesh*>     meshes;
	materials.reserve (5);
	meshes.reserve    (5);

	// temporary data - current mesh buffer
	aiMaterial* curMat	= NULL;
	aiMesh* curMesh		= NULL;
	unsigned int curMatFlags = 0;

	std::vector<aiVector3D> curVertices,curNormals,curTangents,curBitangents;
	std::vector<aiColor4D>  curColors;
	std::vector<aiVector3D> curUVs,curUV2s;

	// some temporary variables
	int textMeaning = 0;
	int vertexFormat = 0; // 0 = normal; 1 = 2 tcoords, 2 = tangents
	bool useColors = false;

	// Parse the XML file
	while (reader->read())	{
		switch (reader->getNodeType())	{
		case EXN_ELEMENT:
			
			if (!ASSIMP_stricmp(reader->getNodeName(),"buffer") && (curMat || curMesh))	{
				// end of previous buffer. A material and a mesh should be there
				if ( !curMat || !curMesh)	{
					DefaultLogger::get()->error("IRRMESH: A buffer must contain a mesh and a material");
					delete curMat;
					delete curMesh;
				}
				else	{
					materials.push_back(curMat); 
					meshes.push_back(curMesh);  
				}
				curMat  = NULL;
				curMesh = NULL;

				curVertices.clear();
				curColors.clear();
				curNormals.clear();
				curUV2s.clear();
				curUVs.clear();
				curTangents.clear();
				curBitangents.clear();
			}
			

			if (!ASSIMP_stricmp(reader->getNodeName(),"material"))	{
				if (curMat)	{
					DefaultLogger::get()->warn("IRRMESH: Only one material description per buffer, please");
					delete curMat;curMat = NULL;
				}
				curMat = ParseMaterial(curMatFlags);
			}
			/* no else here! */ if (!ASSIMP_stricmp(reader->getNodeName(),"vertices"))
			{
				int num = reader->getAttributeValueAsInt("vertexCount");

				if (!num)	{
					// This is possible ... remove the mesh from the list and skip further reading
					DefaultLogger::get()->warn("IRRMESH: Found mesh with zero vertices");

					delete curMat;curMat = NULL;

					curMesh = NULL;
					textMeaning = 0;
					continue;
				}

				curVertices.reserve (num);
				curNormals.reserve  (num);
				curColors.reserve   (num);
				curUVs.reserve      (num);

				// Determine the file format
				const char* t = reader->getAttributeValueSafe("type");
				if (!ASSIMP_stricmp("2tcoords", t))	{
					curUV2s.reserve (num);
					vertexFormat = 1;

					if (curMatFlags & AI_IRRMESH_EXTRA_2ND_TEXTURE)	{
						// *********************************************************
						// We have a second texture! So use this UV channel
						// for it. The 2nd texture can be either a normal
						// texture (solid_2layer or lightmap_xxx) or a normal 
						// map (normal_..., parallax_...)
						// *********************************************************
						int idx = 1;
						aiMaterial* mat = ( aiMaterial* ) curMat;

						if (curMatFlags & AI_IRRMESH_MAT_lightmap){
							mat->AddProperty(&idx,1,AI_MATKEY_UVWSRC_LIGHTMAP(0));
						}
						else if (curMatFlags & AI_IRRMESH_MAT_normalmap_solid){
							mat->AddProperty(&idx,1,AI_MATKEY_UVWSRC_NORMALS(0));
						}
						else if (curMatFlags & AI_IRRMESH_MAT_solid_2layer) {
							mat->AddProperty(&idx,1,AI_MATKEY_UVWSRC_DIFFUSE(1));
						}
					}
				}
				else if (!ASSIMP_stricmp("tangents", t))	{
					curTangents.reserve (num);
					curBitangents.reserve (num);
					vertexFormat = 2;
				}
				else if (ASSIMP_stricmp("standard", t))	{
					delete curMat;
					DefaultLogger::get()->warn("IRRMESH: Unknown vertex format");
				}
				else vertexFormat = 0;
				textMeaning = 1;
			}
			else if (!ASSIMP_stricmp(reader->getNodeName(),"indices"))	{
				if (curVertices.empty() && curMat)	{
					delete curMat;
					throw DeadlyImportError("IRRMESH: indices must come after vertices");
				}

				textMeaning = 2;

				// start a new mesh
				curMesh = new aiMesh();

				// allocate storage for all faces
				curMesh->mNumVertices = reader->getAttributeValueAsInt("indexCount");
				if (!curMesh->mNumVertices)	{
					// This is possible ... remove the mesh from the list and skip further reading
					DefaultLogger::get()->warn("IRRMESH: Found mesh with zero indices");

					// mesh - away
					delete curMesh; curMesh = NULL;

					// material - away
					delete curMat;curMat = NULL;

					textMeaning = 0;
					continue;
				}

				if (curMesh->mNumVertices % 3)	{
					DefaultLogger::get()->warn("IRRMESH: Number if indices isn't divisible by 3");
				}

				curMesh->mNumFaces = curMesh->mNumVertices / 3;
				curMesh->mFaces = new aiFace[curMesh->mNumFaces];

				// setup some members
				curMesh->mMaterialIndex = (unsigned int)materials.size();
				curMesh->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;

				// allocate storage for all vertices
				curMesh->mVertices = new aiVector3D[curMesh->mNumVertices];

				if (curNormals.size() == curVertices.size())	{
					curMesh->mNormals = new aiVector3D[curMesh->mNumVertices];
				}
				if (curTangents.size() == curVertices.size())	{
					curMesh->mTangents = new aiVector3D[curMesh->mNumVertices];
				}
				if (curBitangents.size() == curVertices.size())	{
					curMesh->mBitangents = new aiVector3D[curMesh->mNumVertices];
				}
				if (curColors.size() == curVertices.size() && useColors)	{
					curMesh->mColors[0] = new aiColor4D[curMesh->mNumVertices];
				}
				if (curUVs.size() == curVertices.size())	{
					curMesh->mTextureCoords[0] = new aiVector3D[curMesh->mNumVertices];
				}
				if (curUV2s.size() == curVertices.size())	{
					curMesh->mTextureCoords[1] = new aiVector3D[curMesh->mNumVertices];
				}
			}
			break;

		case EXN_TEXT:
			{
			const char* sz = reader->getNodeData();
			if (textMeaning == 1)	{
				textMeaning = 0;

				// read vertices
				do	{
					SkipSpacesAndLineEnd(&sz);
					aiVector3D temp;aiColor4D c;

					// Read the vertex position
					sz = fast_atoreal_move<float>(sz,(float&)temp.x);
					SkipSpaces(&sz);

					sz = fast_atoreal_move<float>(sz,(float&)temp.y);
					SkipSpaces(&sz);

					sz = fast_atoreal_move<float>(sz,(float&)temp.z);
					SkipSpaces(&sz);
					curVertices.push_back(temp);

					// Read the vertex normals
					sz = fast_atoreal_move<float>(sz,(float&)temp.x);
					SkipSpaces(&sz);

					sz = fast_atoreal_move<float>(sz,(float&)temp.y);
					SkipSpaces(&sz);

					sz = fast_atoreal_move<float>(sz,(float&)temp.z);
					SkipSpaces(&sz);
					curNormals.push_back(temp);

					// read the vertex colors
					uint32_t clr = strtoul16(sz,&sz);	
					ColorFromARGBPacked(clr,c);

					if (!curColors.empty() && c != *(curColors.end()-1))
						useColors = true;

					curColors.push_back(c);
					SkipSpaces(&sz);


					// read the first UV coordinate set
					sz = fast_atoreal_move<float>(sz,(float&)temp.x);
					SkipSpaces(&sz);

					sz = fast_atoreal_move<float>(sz,(float&)temp.y);
					SkipSpaces(&sz);
					temp.z = 0.f;
					temp.y = 1.f - temp.y;  // DX to OGL
					curUVs.push_back(temp);

					// read the (optional) second UV coordinate set
					if (vertexFormat == 1)	{
						sz = fast_atoreal_move<float>(sz,(float&)temp.x);
						SkipSpaces(&sz);

						sz = fast_atoreal_move<float>(sz,(float&)temp.y);
						temp.y = 1.f - temp.y; // DX to OGL
						curUV2s.push_back(temp);
					}
					// read optional tangent and bitangent vectors
					else if (vertexFormat == 2)	{
						// tangents
						sz = fast_atoreal_move<float>(sz,(float&)temp.x);
						SkipSpaces(&sz);

						sz = fast_atoreal_move<float>(sz,(float&)temp.z);
						SkipSpaces(&sz);

						sz = fast_atoreal_move<float>(sz,(float&)temp.y);
						SkipSpaces(&sz);
						temp.y *= -1.0f;
						curTangents.push_back(temp);

						// bitangents
						sz = fast_atoreal_move<float>(sz,(float&)temp.x);
						SkipSpaces(&sz);

						sz = fast_atoreal_move<float>(sz,(float&)temp.z);
						SkipSpaces(&sz);

						sz = fast_atoreal_move<float>(sz,(float&)temp.y);
						SkipSpaces(&sz);
						temp.y *= -1.0f;
						curBitangents.push_back(temp);
					}
				}

				/* IMPORTANT: We assume that each vertex is specified in one
				   line. So we can skip the rest of the line - unknown vertex
				   elements are ignored.
				 */

				while (SkipLine(&sz));
			}
			else if (textMeaning == 2)	{
				textMeaning = 0;

				// read indices
				aiFace* curFace = curMesh->mFaces;
				aiFace* const faceEnd = curMesh->mFaces  + curMesh->mNumFaces;

				aiVector3D* pcV  = curMesh->mVertices;
				aiVector3D* pcN  = curMesh->mNormals;
				aiVector3D* pcT  = curMesh->mTangents;
				aiVector3D* pcB  = curMesh->mBitangents;
				aiColor4D* pcC0  = curMesh->mColors[0];
				aiVector3D* pcT0 = curMesh->mTextureCoords[0];
				aiVector3D* pcT1 = curMesh->mTextureCoords[1];

				unsigned int curIdx = 0;
				unsigned int total = 0;
				while(SkipSpacesAndLineEnd(&sz))	{
					if (curFace >= faceEnd)	{
						DefaultLogger::get()->error("IRRMESH: Too many indices");
						break;
					}
					if (!curIdx)	{
						curFace->mNumIndices = 3;
						curFace->mIndices = new unsigned int[3];
					}

					unsigned int idx = strtoul10(sz,&sz);
					if (idx >= curVertices.size())	{
						DefaultLogger::get()->error("IRRMESH: Index out of range");
						idx = 0;
					}

					curFace->mIndices[curIdx] = total++;

					*pcV++ = curVertices[idx];
					if (pcN)*pcN++ = curNormals[idx];
					if (pcT)*pcT++ = curTangents[idx];
					if (pcB)*pcB++ = curBitangents[idx];
					if (pcC0)*pcC0++ = curColors[idx];
					if (pcT0)*pcT0++ = curUVs[idx];
					if (pcT1)*pcT1++ = curUV2s[idx];

					if (++curIdx == 3)	{
						++curFace;
						curIdx = 0;
					}
				}

				if (curFace != faceEnd)
					DefaultLogger::get()->error("IRRMESH: Not enough indices");

				// Finish processing the mesh - do some small material workarounds
				if (curMatFlags & AI_IRRMESH_MAT_trans_vertex_alpha && !useColors)	{
					// Take the opacity value of the current material
					// from the common vertex color alpha
					aiMaterial* mat = (aiMaterial*)curMat;
					mat->AddProperty(&curColors[0].a,1,AI_MATKEY_OPACITY);
				}
			}}
			break;

			default:

				// GCC complains here ...
				break;

		};
	}

	// End of the last buffer. A material and a mesh should be there
	if (curMat || curMesh)	{
		if ( !curMat || !curMesh)	{
			DefaultLogger::get()->error("IRRMESH: A buffer must contain a mesh and a material");
			delete curMat;
			delete curMesh;
		}
		else	{
			materials.push_back(curMat); 
			meshes.push_back(curMesh);  
		}
	}

	if (materials.empty())
		throw DeadlyImportError("IRRMESH: Unable to read a mesh from this file");


	// now generate the output scene
	pScene->mNumMeshes = (unsigned int)meshes.size();
	pScene->mMeshes = new aiMesh*[pScene->mNumMeshes];
	for (unsigned int i = 0; i < pScene->mNumMeshes;++i)	{
		pScene->mMeshes[i] = meshes[i];

		// clean this value ...
		pScene->mMeshes[i]->mNumUVComponents[3] = 0;
	}

	pScene->mNumMaterials = (unsigned int)materials.size();
	pScene->mMaterials = new aiMaterial*[pScene->mNumMaterials];
	::memcpy(pScene->mMaterials,&materials[0],sizeof(void*)*pScene->mNumMaterials);

	pScene->mRootNode = new aiNode();
	pScene->mRootNode->mName.Set("<IRRMesh>");
	pScene->mRootNode->mNumMeshes = pScene->mNumMeshes;
	pScene->mRootNode->mMeshes = new unsigned int[pScene->mNumMeshes];

	for (unsigned int i = 0; i < pScene->mNumMeshes;++i)
		pScene->mRootNode->mMeshes[i] = i;

	// clean up and return
	delete reader;
	AI_DEBUG_INVALIDATE_PTR(reader);
}