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

/** @file  Q3DLoader.cpp
 *  @brief Implementation of the Q3D importer class
 */

#include "AssimpPCH.h"
#ifndef ASSIMP_BUILD_NO_Q3D_IMPORTER

// internal headers
#include "Q3DLoader.h"
#include "StreamReader.h"
#include "fast_atof.h"

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
Q3DImporter::Q3DImporter()
{}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well 
Q3DImporter::~Q3DImporter()
{}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file. 
bool Q3DImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool checkSig) const
{
	const std::string extension = GetExtension(pFile);

	if (extension == "q3s" || extension == "q3o")
		return true;
	else if (!extension.length() || checkSig)	{
		if (!pIOHandler)
			return true;
		const char* tokens[] = {"quick3Do","quick3Ds"};
		return SearchFileHeaderForToken(pIOHandler,pFile,tokens,2);
	}
	return false;
}

// ------------------------------------------------------------------------------------------------
void Q3DImporter::GetExtensionList(std::set<std::string>& extensions)
{
	extensions.insert("q3o");
	extensions.insert("q3s");
}

// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure. 
void Q3DImporter::InternReadFile( const std::string& pFile, 
	aiScene* pScene, IOSystem* pIOHandler)
{
	StreamReaderLE stream(pIOHandler->Open(pFile,"rb"));

	// The header is 22 bytes large
	if (stream.GetRemainingSize() < 22)
		throw DeadlyImportError("File is either empty or corrupt: " + pFile);

	// Check the file's signature
	if (ASSIMP_strincmp( (const char*)stream.GetPtr(), "quick3Do", 8 ) &&
		ASSIMP_strincmp( (const char*)stream.GetPtr(), "quick3Ds", 8 ))
	{
		throw DeadlyImportError("Not a Quick3D file. Signature string is: " + 
			std::string((const char*)stream.GetPtr(),8));
	}

	// Print the file format version
	DefaultLogger::get()->info("Quick3D File format version: " + 
		std::string(&((const char*)stream.GetPtr())[8],2));

	// ... an store it
	char major = ((const char*)stream.GetPtr())[8];
	char minor = ((const char*)stream.GetPtr())[9];

	stream.IncPtr(10);
	unsigned int numMeshes    = (unsigned int)stream.GetI4();
	unsigned int numMats      = (unsigned int)stream.GetI4();
	unsigned int numTextures  = (unsigned int)stream.GetI4();

	std::vector<Material> materials;
	materials.reserve(numMats);

	std::vector<Mesh> meshes;
	meshes.reserve(numMeshes);

	// Allocate the scene root node
	pScene->mRootNode = new aiNode();

	aiColor3D fgColor (0.6f,0.6f,0.6f);

	// Now read all file chunks
	while (true)
	{
		if (stream.GetRemainingSize() < 1)break;
		char c = stream.GetI1();
		switch (c)
		{
			// Meshes chunk
		case 'm':
			{
				for (unsigned int quak = 0; quak < numMeshes; ++quak)
				{
					meshes.push_back(Mesh());
					Mesh& mesh = meshes.back();

					// read all vertices
					unsigned int numVerts = (unsigned int)stream.GetI4();
					if (!numVerts)
						throw DeadlyImportError("Quick3D: Found mesh with zero vertices");

					std::vector<aiVector3D>& verts = mesh.verts;
					verts.resize(numVerts);

					for (unsigned int i = 0; i < numVerts;++i)
					{
						verts[i].x = stream.GetF4();
						verts[i].y = stream.GetF4();
						verts[i].z = stream.GetF4();
					}

					// read all faces
					numVerts = (unsigned int)stream.GetI4();
					if (!numVerts)
						throw DeadlyImportError("Quick3D: Found mesh with zero faces");

					std::vector<Face >& faces = mesh.faces;
					faces.reserve(numVerts);

					// number of indices
					for (unsigned int i = 0; i < numVerts;++i)
					{
						faces.push_back(Face(stream.GetI2()) );
						if (faces.back().indices.empty())
							throw DeadlyImportError("Quick3D: Found face with zero indices");
					}

					// indices
					for (unsigned int i = 0; i < numVerts;++i)
					{
						Face& vec = faces[i];
						for (unsigned int a = 0; a < (unsigned int)vec.indices.size();++a)
							vec.indices[a] = stream.GetI4();
					}

					// material indices
					for (unsigned int i = 0; i < numVerts;++i)
					{
						faces[i].mat = (unsigned int)stream.GetI4();
					}

					// read all normals
					numVerts = (unsigned int)stream.GetI4();
					std::vector<aiVector3D>& normals = mesh.normals;
					normals.resize(numVerts);

					for (unsigned int i = 0; i < numVerts;++i)
					{
						normals[i].x = stream.GetF4();
						normals[i].y = stream.GetF4();
						normals[i].z = stream.GetF4();
					}

					numVerts = (unsigned int)stream.GetI4();
					if (numTextures && numVerts)
					{
						// read all texture coordinates
						std::vector<aiVector3D>& uv = mesh.uv;
						uv.resize(numVerts);

						for (unsigned int i = 0; i < numVerts;++i)
						{
							uv[i].x = stream.GetF4();
							uv[i].y = stream.GetF4();
						}

						// UV indices
						for (unsigned int i = 0; i < (unsigned int)faces.size();++i)
						{
							Face& vec = faces[i];
							for (unsigned int a = 0; a < (unsigned int)vec.indices.size();++a)
							{
								vec.uvindices[a] = stream.GetI4();
								if (!i && !a)
									mesh.prevUVIdx = vec.uvindices[a];
								else if (vec.uvindices[a] != mesh.prevUVIdx)
									mesh.prevUVIdx = UINT_MAX;
							}
						}
					}

					// we don't need the rest, but we need to get to the next chunk
					stream.IncPtr(36);
					if (minor > '0' && major == '3')
						stream.IncPtr(mesh.faces.size());
				}
				// stream.IncPtr(4); // unknown value here
			}
			break;

			// materials chunk 
		case 'c':

			for (unsigned int i = 0; i < numMats; ++i)
			{
				materials.push_back(Material());
				Material& mat = materials.back();

				// read the material name
				while (( c = stream.GetI1()))
					mat.name.data[mat.name.length++] = c;
				
				// add the terminal character
				mat.name.data[mat.name.length] = '\0';

				// read the ambient color
				mat.ambient.r = stream.GetF4();
				mat.ambient.g = stream.GetF4();
				mat.ambient.b = stream.GetF4();

				// read the diffuse color
				mat.diffuse.r = stream.GetF4();
				mat.diffuse.g = stream.GetF4();
				mat.diffuse.b = stream.GetF4();

				// read the ambient color
				mat.specular.r = stream.GetF4();
				mat.specular.g = stream.GetF4();
				mat.specular.b = stream.GetF4();

				// read the transparency
				mat.transparency = stream.GetF4();

				// unknown value here
				// stream.IncPtr(4);
				// FIX: it could be the texture index ...
				mat.texIdx = (unsigned int)stream.GetI4();
			}

			break;

			// texture chunk
		case 't':

			pScene->mNumTextures = numTextures;
			if (!numTextures)break;
			pScene->mTextures    = new aiTexture*[pScene->mNumTextures];
			// to make sure we won't crash if we leave through an exception
			::memset(pScene->mTextures,0,sizeof(void*)*pScene->mNumTextures);
			for (unsigned int i = 0; i < pScene->mNumTextures; ++i)
			{
				aiTexture* tex = pScene->mTextures[i] = new aiTexture();

				// skip the texture name
				while (stream.GetI1());

				// read texture width and height
				tex->mWidth  = (unsigned int)stream.GetI4();
				tex->mHeight = (unsigned int)stream.GetI4();

				if (!tex->mWidth || !tex->mHeight)
					throw DeadlyImportError("Quick3D: Invalid texture. Width or height is zero");

				register unsigned int mul = tex->mWidth * tex->mHeight;
				aiTexel* begin = tex->pcData = new aiTexel[mul];
				aiTexel* const end = & begin [mul];

				for (;begin != end; ++begin)
				{
					begin->r = stream.GetI1();
					begin->g = stream.GetI1();
					begin->b = stream.GetI1();
					begin->a = 0xff;
				}
			}

			break;

			// scene chunk
		case 's':
			{
				// skip position and rotation
				stream.IncPtr(12);

				for (unsigned int i = 0; i < 4;++i)
					for (unsigned int a = 0; a < 4;++a)
						pScene->mRootNode->mTransformation[i][a] = stream.GetF4();
				
				stream.IncPtr(16);

				// now setup a single camera
				pScene->mNumCameras = 1;
				pScene->mCameras = new aiCamera*[1];
				aiCamera* cam = pScene->mCameras[0] = new aiCamera();
				cam->mPosition.x = stream.GetF4();
				cam->mPosition.y = stream.GetF4();
				cam->mPosition.z = stream.GetF4();
				cam->mName.Set("Q3DCamera");

				// skip eye rotation for the moment
				stream.IncPtr(12);

				// read the default material color
				fgColor .r = stream.GetF4();
				fgColor .g = stream.GetF4();
				fgColor .b = stream.GetF4();

				// skip some unimportant properties
				stream.IncPtr(29);

				// setup a single point light with no attenuation
				pScene->mNumLights = 1;
				pScene->mLights = new aiLight*[1];
				aiLight* light = pScene->mLights[0] = new aiLight();
				light->mName.Set("Q3DLight");
				light->mType = aiLightSource_POINT;

				light->mAttenuationConstant  = 1;
				light->mAttenuationLinear    = 0;
				light->mAttenuationQuadratic = 0;

				light->mColorDiffuse.r = stream.GetF4();
				light->mColorDiffuse.g = stream.GetF4();
				light->mColorDiffuse.b = stream.GetF4();

				light->mColorSpecular = light->mColorDiffuse;


				// We don't need the rest, but we need to know where
				// this fucking chunk ends.
				unsigned int temp = (unsigned int)(stream.GetI4() * stream.GetI4());

				// skip the background file name
				while (stream.GetI1());

				// skip background texture data + the remaining fields 
				stream.IncPtr(temp*3 + 20); // 4 bytes of unknown data here

				// TODO
				goto outer;
			}
			break;

		default:
			throw DeadlyImportError("Quick3D: Unknown chunk");
			break;
		};
	}
outer:

	// If we have no mesh loaded - break here
	if (meshes.empty())
		throw DeadlyImportError("Quick3D: No meshes loaded");

	// If we have no materials loaded - generate a default mat
	if (materials.empty())
	{
		DefaultLogger::get()->info("Quick3D: No material found, generating one");
		materials.push_back(Material());
		materials.back().diffuse  = fgColor ;
	}

	// find out which materials we'll need
	typedef std::pair<unsigned int, unsigned int> FaceIdx;
	typedef std::vector< FaceIdx > FaceIdxArray;
	FaceIdxArray* fidx = new FaceIdxArray[materials.size()]; 

	unsigned int p = 0;
	for (std::vector<Mesh>::iterator it = meshes.begin(), end = meshes.end();
		 it != end; ++it,++p)
	{
		unsigned int q = 0;
		for (std::vector<Face>::iterator fit = (*it).faces.begin(), fend = (*it).faces.end();
			 fit != fend; ++fit,++q)
		{
			if ((*fit).mat >= materials.size())
			{
				DefaultLogger::get()->warn("Quick3D: Material index overflow");
				(*fit).mat = 0;
			}
			if (fidx[(*fit).mat].empty())++pScene->mNumMeshes;
			fidx[(*fit).mat].push_back( FaceIdx(p,q) );
		}
	}
	pScene->mNumMaterials = pScene->mNumMeshes;
	pScene->mMaterials = new aiMaterial*[pScene->mNumMaterials];
	pScene->mMeshes = new aiMesh*[pScene->mNumMaterials];

	for (unsigned int i = 0, real = 0; i < (unsigned int)materials.size(); ++i)
	{
		if (fidx[i].empty())continue;

		// Allocate a mesh and a material
		aiMesh* mesh = pScene->mMeshes[real] = new aiMesh();
		aiMaterial* mat = new aiMaterial();
		pScene->mMaterials[real] = mat;

		mesh->mMaterialIndex = real;

		// Build the output material
		Material& srcMat = materials[i];
		mat->AddProperty(&srcMat.diffuse,  1,AI_MATKEY_COLOR_DIFFUSE);
		mat->AddProperty(&srcMat.specular, 1,AI_MATKEY_COLOR_SPECULAR);
		mat->AddProperty(&srcMat.ambient,  1,AI_MATKEY_COLOR_AMBIENT);
	
		// NOTE: Ignore transparency for the moment - it seems
		// unclear how to interpret the data
#if 0
		if (!(minor > '0' && major == '3'))
			srcMat.transparency = 1.0f - srcMat.transparency;
		mat->AddProperty(&srcMat.transparency, 1, AI_MATKEY_OPACITY);
#endif

		// add shininess - Quick3D seems to use it ins its viewer
		srcMat.transparency = 16.f;
		mat->AddProperty(&srcMat.transparency, 1, AI_MATKEY_SHININESS);

		int m = (int)aiShadingMode_Phong;
		mat->AddProperty(&m, 1, AI_MATKEY_SHADING_MODEL);

		if (srcMat.name.length)
			mat->AddProperty(&srcMat.name,AI_MATKEY_NAME);

		// Add a texture
		if (srcMat.texIdx < pScene->mNumTextures || real < pScene->mNumTextures)
		{
			srcMat.name.data[0] = '*';
			srcMat.name.length  = ASSIMP_itoa10(&srcMat.name.data[1],1000,
				(srcMat.texIdx < pScene->mNumTextures ? srcMat.texIdx : real));
			mat->AddProperty(&srcMat.name,AI_MATKEY_TEXTURE_DIFFUSE(0));
		}

		mesh->mNumFaces = (unsigned int)fidx[i].size();
		aiFace* faces = mesh->mFaces = new aiFace[mesh->mNumFaces];

		// Now build the output mesh. First find out how many
		// vertices we'll need
		for (FaceIdxArray::const_iterator it = fidx[i].begin(),end = fidx[i].end();
			 it != end; ++it)
		{
			mesh->mNumVertices += (unsigned int)meshes[(*it).first].faces[
				(*it).second].indices.size();
		}

		aiVector3D* verts = mesh->mVertices = new aiVector3D[mesh->mNumVertices];
		aiVector3D* norms = mesh->mNormals  = new aiVector3D[mesh->mNumVertices];
		aiVector3D* uv;
		if (real < pScene->mNumTextures)
		{
			uv = mesh->mTextureCoords[0] =  new aiVector3D[mesh->mNumVertices];
			mesh->mNumUVComponents[0]    =  2;
		}
		else uv = NULL;

		// Build the final array
		unsigned int cnt = 0;
		for (FaceIdxArray::const_iterator it = fidx[i].begin(),end = fidx[i].end();
			 it != end; ++it, ++faces)
		{
			Mesh& m    = meshes[(*it).first];
			Face& face = m.faces[(*it).second];
			faces->mNumIndices = (unsigned int)face.indices.size();
			faces->mIndices = new unsigned int [faces->mNumIndices]; 


			aiVector3D faceNormal;
			bool fnOK = false;

			for (unsigned int n = 0; n < faces->mNumIndices;++n, ++cnt, ++norms, ++verts)
			{
				if (face.indices[n] >= m.verts.size())
				{
					DefaultLogger::get()->warn("Quick3D: Vertex index overflow");
					face.indices[n] = 0;
				}

				// copy vertices
				*verts =  m.verts[ face.indices[n] ];

				if (face.indices[n] >= m.normals.size() && faces->mNumIndices >= 3)
				{
					// we have no normal here - assign the face normal
					if (!fnOK)
					{
						const aiVector3D& pV1 =  m.verts[ face.indices[0] ];
						const aiVector3D& pV2 =  m.verts[ face.indices[1] ];
						const aiVector3D& pV3 =  m.verts[ face.indices.size() - 1 ];
						faceNormal = (pV2 - pV1) ^ (pV3 - pV1).Normalize();
						fnOK = true;
					}
					*norms = faceNormal;
				}
				else *norms =  m.normals[ face.indices[n] ];

				// copy texture coordinates
				if (uv && m.uv.size())
				{
					if (m.prevUVIdx != 0xffffffff && m.uv.size() >= m.verts.size()) // workaround
					{
						*uv = m.uv[face.indices[n]];
					}
					else
					{
						if (face.uvindices[n] >= m.uv.size())
						{
							DefaultLogger::get()->warn("Quick3D: Texture coordinate index overflow");
							face.uvindices[n] = 0;
						}
						*uv = m.uv[face.uvindices[n]];
					}
					uv->y = 1.f - uv->y;
					++uv;
				}

				// setup the new vertex index
				faces->mIndices[n] = cnt;
			}

		}
		++real;
	}

	// Delete our nice helper array
	delete[] fidx;

	// Now we need to attach the meshes to the root node of the scene
	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;

	/*pScene->mRootNode->mTransformation *= aiMatrix4x4(
		1.f, 0.f, 0.f, 0.f,
	    0.f, -1.f,0.f, 0.f,
		0.f, 0.f, 1.f, 0.f,
		0.f, 0.f, 0.f, 1.f);*/

	// Add cameras and light sources to the scene root node
	pScene->mRootNode->mNumChildren = pScene->mNumLights+pScene->mNumCameras;
	if (pScene->mRootNode->mNumChildren)
	{
		pScene->mRootNode->mChildren = new aiNode* [ pScene->mRootNode->mNumChildren ];

		// the light source
		aiNode* nd = pScene->mRootNode->mChildren[0] = new aiNode();
		nd->mParent = pScene->mRootNode;
		nd->mName.Set("Q3DLight");
		nd->mTransformation = pScene->mRootNode->mTransformation;
		nd->mTransformation.Inverse();

		// camera
		nd = pScene->mRootNode->mChildren[1] = new aiNode();
		nd->mParent = pScene->mRootNode;
		nd->mName.Set("Q3DCamera");
		nd->mTransformation = pScene->mRootNode->mChildren[0]->mTransformation;
	}
}

#endif // !! ASSIMP_BUILD_NO_Q3D_IMPORTER