#include "ObjFileImporter.h"
#include "ObjFileParser.h"
#include "ObjFileData.h"
#include "../include/IOStream.h"
#include "../include/IOSystem.h"
#include "../include/aiMesh.h"
#include "../include/aiScene.h"
#include "../include/aiAssert.h"
#include "MaterialSystem.h"
#include "../include/DefaultLogger.h"

#include <boost/scoped_ptr.hpp>
#include <boost/format.hpp>

namespace Assimp
{
// ------------------------------------------------------------------------------------------------

using namespace std;

//!	Obj-file-format extention
const string ObjFileImporter::OBJ_EXT = "obj";

// ------------------------------------------------------------------------------------------------
//	Default constructor
ObjFileImporter::ObjFileImporter() :
	m_pRootObject(NULL),
	m_strAbsPath("\\")
{
}

// ------------------------------------------------------------------------------------------------
//	Destructor
ObjFileImporter::~ObjFileImporter()
{
	// Release root object instance
	if (NULL != m_pRootObject)
	{
		delete m_pRootObject;
		m_pRootObject = NULL;
	}
}

// ------------------------------------------------------------------------------------------------
//	Returns true, fi file is an obj file
bool ObjFileImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler) const
{
	if (pFile.empty())
		return false;

	string::size_type pos = pFile.find_last_of(".");
	if (string::npos == pos)
		return false;
	
	const string ext = pFile.substr(pos+1, pFile.size() - pos - 1);
	if (ext == OBJ_EXT)
		return true;

	return false;
}

// ------------------------------------------------------------------------------------------------
//	Obj-file import implementation
void ObjFileImporter::InternReadFile( const std::string& pFile, aiScene* pScene, IOSystem* pIOHandler)
{
	// Read file into memory
	const std::string mode  = "rb";
	boost::scoped_ptr<IOStream> file( pIOHandler->Open( pFile, mode));
	if (NULL == file.get())
		throw new ImportErrorException( "Failed to open file " + pFile + ".");

	// Get the filesize and vaslidate it, throwing an exception when failes
	size_t fileSize = file->FileSize();
	if( fileSize < 16)
		throw new ImportErrorException( "OBJ-file is too small.");

	// Allocate buffer and read file into it
	m_Buffer.resize( fileSize );
	const size_t readsize = file->Read(&m_Buffer.front(), sizeof(char), fileSize);
	assert (readsize == fileSize);

	//
	std::string strDirectory("\\"), strModelName;
	std::string::size_type pos = pFile.find_last_of("\\");
	if (pos != std::string::npos)
	{
		strDirectory = pFile.substr(0, pos);
		strModelName = pFile.substr(pos+1, pFile.size() - pos - 1);
	}
	else
	{
		strModelName = pFile;
	}
	
	// parse the file into a temporary representation
	ObjFileParser parser(m_Buffer, strDirectory, strModelName);

	// And create the proper return structures out of it
	CreateDataFromImport(parser.GetModel(), pScene);
}

// ------------------------------------------------------------------------------------------------
//	Create the data from parsed obj-file
void ObjFileImporter::CreateDataFromImport(const ObjFile::Model* pModel, aiScene* pScene)
{
	if (0L == pModel)
		return;
		
	// Create the root node of the scene
	pScene->mRootNode = new aiNode();
	if (!pModel->m_ModelName.empty())
	{
		// Set the name of the scene
		pScene->mRootNode->mName.Set(pModel->m_ModelName);
	}
	else
	{
		// This is an error, so break down the application
		assert (false);
	}

	// Create nodes for the whole scene	
	std::vector<aiMesh*> MeshArray;
	for (size_t index = 0; index < pModel->m_Objects.size(); index++)
	{
		createNodes(pModel, pModel->m_Objects[ index ], pScene->mRootNode, pScene, MeshArray);
	}

	// Create mesh pointer buffer for this scene
	if (pScene->mNumMeshes > 0)
	{
		pScene->mMeshes = new aiMesh*[ MeshArray.size() ];
		for (size_t index =0; index < MeshArray.size(); index++)
		{
			pScene->mMeshes [ index ] = MeshArray[ index ];
		}
	}

	// Create all materials
	for (size_t index = 0; index < pModel->m_Objects.size(); index++)
	{
		createMaterial( pModel, pModel->m_Objects[ index ], pScene );
	}
}

// ------------------------------------------------------------------------------------------------
//	Creates all nodes of the model
aiNode *ObjFileImporter::createNodes(const ObjFile::Model* pModel, const ObjFile::Object* pData, 
									 aiNode *pParent, aiScene* pScene, 
									 std::vector<aiMesh*> &MeshArray)
{
	if (NULL == pData)
		return NULL;
	
	// Store older mesh size to be able to computate mesh offsets for new mesh instances
	size_t oldMeshSize = MeshArray.size();
	aiNode *pNode = new aiNode();
	
	if (pParent != NULL)
		this->appendChildToParentNode(pParent, pNode);

	aiMesh *pMesh = NULL;
	for (unsigned int meshIndex = 0; meshIndex < pModel->m_Meshes.size(); meshIndex++)
	{
		pMesh = new aiMesh();
		MeshArray.push_back( pMesh );
		createTopology( pModel, pData, meshIndex, pMesh );	
	}

	// Create all nodes from the subobjects stored in the current object
	if (!pData->m_SubObjects.empty())
	{
		pNode->mNumChildren = (unsigned int)pData->m_SubObjects.size();
		pNode->mChildren = new aiNode*[pData->m_SubObjects.size()];
		pNode->mNumMeshes = 1;
		pNode->mMeshes = new unsigned int[1];

		// Loop over all child objects, TODO
		/*for (size_t index = 0; index < pData->m_SubObjects.size(); index++)
		{
			// Create all child nodes
			pNode->mChildren[ index ] = createNodes( pModel, pData, pNode, pScene, MeshArray );
			for (unsigned int meshIndex = 0; meshIndex < pData->m_SubObjects[ index ]->m_Meshes.size(); meshIndex++)
			{
				pMesh = new aiMesh();
				MeshArray.push_back( pMesh );
				createTopology( pModel, pData, meshIndex, pMesh );
			}			
			
			// Create material of this object
			createMaterial(pModel, pData->m_SubObjects[ index ], pScene);
		}*/
	}

	// Set mesh instances into scene- and node-instances
	const size_t meshSizeDiff = MeshArray.size()- oldMeshSize;
	if ( meshSizeDiff > 0 )
	{
		pNode->mMeshes = new unsigned int[ meshSizeDiff ];
		pNode->mNumMeshes = meshSizeDiff;
		size_t index = 0;
		for (size_t i = oldMeshSize; i < MeshArray.size(); i++)
		{
			pNode->mMeshes[ index ] = pScene->mNumMeshes;
			pScene->mNumMeshes++;
			index++;
		}
	}
	
	return pNode;
}

// ------------------------------------------------------------------------------------------------
//	Create topology data
void ObjFileImporter::createTopology(const ObjFile::Model* pModel, 
									 const ObjFile::Object* pData, 
									 unsigned int uiMeshIndex,
									 aiMesh* pMesh )
{
	// Checking preconditions
	ai_assert( NULL != pModel );
	if (NULL == pData)
		return;

	// Create faces
	ObjFile::Mesh *pObjMesh = pModel->m_Meshes[ uiMeshIndex ];
	pMesh->mNumFaces = (unsigned int) pObjMesh->m_Faces.size();
	pMesh->mFaces = new aiFace[ pMesh->mNumFaces ];
	pMesh->mMaterialIndex = pObjMesh->m_uiMaterialIndex;

	// Copy all data from all stored meshes
	for (size_t index = 0; index < pObjMesh->m_Faces.size(); index++)
	{
		aiFace *pFace = &pMesh->mFaces[ index ];
		const unsigned int uiNumIndices = (unsigned int) pObjMesh->m_Faces[ index ]->m_pVertices->size();
		pFace->mNumIndices = (unsigned int) uiNumIndices;
		if (pFace->mNumIndices > 0)
		{
			pFace->mIndices = new unsigned int[ uiNumIndices ];
			ObjFile::Face::IndexArray *pIndexArray = pObjMesh->m_Faces[ index ]->m_pVertices;
			ai_assert ( NULL != pIndexArray );
			for ( size_t a=0; a<pFace->mNumIndices; a++ )
			{
				pFace->mIndices[ a ] = pIndexArray->at( a );
			}
		}
		else
		{
			pFace->mIndices = NULL;
		}
	}

	// Create mesh vertices
	createVertexArray(pModel, pData, uiMeshIndex, pMesh);
}

// ------------------------------------------------------------------------------------------------
void ObjFileImporter::createVertexArray(const ObjFile::Model* pModel, 
										const ObjFile::Object* pCurrentObject, 
										unsigned int uiMeshIndex,
										aiMesh* pMesh)
{
	// Checking preconditions
	ai_assert ( NULL != pCurrentObject );
	
	// Break, if no faces are stored in object
	if (pCurrentObject->m_Faces.empty())
		return;

	// Get current mesh
	ObjFile::Mesh *pObjMesh = pModel->m_Meshes[ uiMeshIndex ];
	if ( NULL == pObjMesh )
		return;

	// Copy vertices of this mesh instance
	pMesh->mNumVertices = (unsigned int) pObjMesh->m_uiNumIndices;
	pMesh->mVertices = new aiVector3D[ pMesh->mNumVertices ];
	
	// Allocate buffer for normal vectors
	if ( !pModel->m_Normals.empty() )
		pMesh->mNormals = new aiVector3D[ pMesh->mNumVertices ];
	
	// Allocate buffer for texture coordinates
	if ( !pModel->m_TextureCoord.empty() )
	{
		for ( size_t i=0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; i++)
			pMesh->mTextureCoords[ i ] = new aiVector3D[ pModel->m_TextureCoord.size() ];
	}
	
	// Copy vertices, normals and textures into aiMesh instance
	unsigned int newIndex = 0;
	for ( size_t index=0; index < pObjMesh->m_Faces.size(); index++ )
	{
		// get destination face
		aiFace *pDestFace = &pMesh->mFaces[ index ];
		
		// get source face
		ObjFile::Face *pSourceFace = pObjMesh->m_Faces[ index ]; 

		// Copy all index arrays
		for ( size_t vertexIndex = 0; vertexIndex < pSourceFace->m_pVertices->size(); vertexIndex++ )
		{
			unsigned int vertex = pSourceFace->m_pVertices->at( vertexIndex );
			assert ( vertex < pModel->m_Vertices.size() );
			pMesh->mVertices[ newIndex ] = *pModel->m_Vertices[ vertex ];
			
			if ( !pModel->m_Normals.empty() )
			{
				const unsigned int normal = pSourceFace->m_pNormals->at( vertexIndex );
				assert( normal < pModel->m_Normals.size() );
				pMesh->mNormals[ newIndex ] = *pModel->m_Normals[ normal ];
			}
			
			if ( !pModel->m_TextureCoord.empty() )
			{
				const unsigned int tex = pSourceFace->m_pTexturCoords->at( vertexIndex );
				ai_assert ( tex < pModel->m_TextureCoord.size() );
				for ( size_t i=0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; i++)
				{
					aiVector2D coord2d = *pModel->m_TextureCoord[ tex ];
					pMesh->mTextureCoords[ i ][ newIndex ] = aiVector3D( coord2d.x, coord2d.y, 0.0 );
				}
			}

			assert( pMesh->mNumVertices > newIndex );
			pDestFace->mIndices[ vertexIndex ] = newIndex;
			newIndex++;
		}
	}	
}

// ------------------------------------------------------------------------------------------------
void ObjFileImporter::countObjects(const std::vector<ObjFile::Object*> &rObjects, int &iNumMeshes)
{
	iNumMeshes = 0;
	if (rObjects.empty())	
		return;

	iNumMeshes += (unsigned int)rObjects.size();
	for (std::vector<ObjFile::Object*>::const_iterator it = rObjects.begin();
		it != rObjects.end(); 
		++it)
	{
		if (!(*it)->m_SubObjects.empty())
		{
			countObjects((*it)->m_SubObjects, iNumMeshes);
		}
	}
}

// ------------------------------------------------------------------------------------------------
void ObjFileImporter::createMaterial(const ObjFile::Model* pModel, const ObjFile::Object* pData, 
									 aiScene* pScene)
{
	ai_assert (NULL != pScene);
	if (NULL == pData)
		return;

	const unsigned int numMaterials = (unsigned int) pModel->m_MaterialLib.size();
	pScene->mNumMaterials = 0;
	if ( pModel->m_MaterialLib.empty() )
		return;
	
	pScene->mMaterials = new aiMaterial*[ numMaterials ];
	for ( unsigned int matIndex = 0; matIndex < numMaterials; matIndex++ )
	{
		Assimp::MaterialHelper* mat = new Assimp::MaterialHelper();
		
		// Store material name
		std::map<std::string, ObjFile::Material*>::const_iterator it = pModel->m_MaterialMap.find( pModel->m_MaterialLib[ matIndex ] );
		
		// No material found, use the default material
		if ( pModel->m_MaterialMap.end() == it)
			continue;

		ObjFile::Material *pCurrentMaterial = (*it).second;
		mat->AddProperty( &pCurrentMaterial->MaterialName, AI_MATKEY_NAME );
		mat->AddProperty<int>( &pCurrentMaterial->illumination_model, 1, AI_MATKEY_SHADING_MODEL);

		// Adding material colors
		mat->AddProperty( &pCurrentMaterial->ambient, 1, AI_MATKEY_COLOR_AMBIENT );
		mat->AddProperty( &pCurrentMaterial->diffuse, 1, AI_MATKEY_COLOR_DIFFUSE );
		mat->AddProperty( &pCurrentMaterial->specular, 1, AI_MATKEY_COLOR_SPECULAR );
		mat->AddProperty( &pCurrentMaterial->shineness, 1, AI_MATKEY_SHININESS );

		// Adding textures
		if ( 0 != pCurrentMaterial->texture.length )
			mat->AddProperty( &pCurrentMaterial->texture, AI_MATKEY_TEXTURE_DIFFUSE(0));
		
		// Store material property info in material array in scene
		pScene->mMaterials[ pScene->mNumMaterials ] = mat;
		pScene->mNumMaterials++;
	}
	
	// Test number of created materials.
	ai_assert( pScene->mNumMaterials == numMaterials );
}

// ------------------------------------------------------------------------------------------------
//	Appends this node to the parent node
void ObjFileImporter::appendChildToParentNode(aiNode *pParent, aiNode *pChild)
{
	// Checking preconditions
	ai_assert (NULL != pParent);
	ai_assert (NULL != pChild);

	// Assign parent to child
	pChild->mParent = pParent;
	size_t sNumChildren = 0;
	
	// If already children was assigned to the parent node, store them in a 
	std::vector<aiNode*> temp;
	if (pParent->mChildren != NULL)
	{
		sNumChildren = pParent->mNumChildren;
		ai_assert (0 != sNumChildren);
		for (size_t index = 0; index < pParent->mNumChildren; index++)
		{
			temp.push_back(pParent->mChildren [ index ] );
		}
		delete [] pParent->mChildren;
	}
	
	// Copy node instances into parent node
	pParent->mNumChildren++;
	pParent->mChildren = new aiNode*[ pParent->mNumChildren ];
	for (size_t index = 0; index < pParent->mNumChildren-1; index++)
	{
		pParent->mChildren[ index ] = temp [ index ];
	}
	pParent->mChildren[ pParent->mNumChildren-1 ] = pChild;
}

// ------------------------------------------------------------------------------------------------

}	// Namespace Assimp