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


#ifndef ASSIMP_BUILD_NO_Q3D_IMPORTER

// internal headers
#include "Q3DLoader.h"
#include <assimp/StreamReader.h>
#include <assimp/fast_atof.h>
#include <assimp/IOSystem.hpp>
#include <assimp/DefaultLogger.hpp>
#include <assimp/scene.h>
#include <assimp/importerdesc.h>

using namespace Assimp;

static const aiImporterDesc desc = {
    "Quick3D Importer",
    "",
    "",
    "http://www.quick3d.com/",
    aiImporterFlags_SupportBinaryFlavour,
    0,
    0,
    0,
    0,
    "q3o q3s"
};

// ------------------------------------------------------------------------------------------------
// 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;
}

// ------------------------------------------------------------------------------------------------
const aiImporterDesc* Q3DImporter::GetInfo () const
{
    return &desc;
}

// ------------------------------------------------------------------------------------------------
// 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
    ASSIMP_LOG_INFO_F("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
                c = stream.GetI1();
                while (c) {
                    mat.name.data[mat.name.length++] = c;
                    c = stream.GetI1();
                }

                // 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");
                }

                unsigned int mul = tex->mWidth * tex->mHeight;
                aiTexel* begin = tex->pcData = new aiTexel[mul];
                aiTexel* const end = & begin[mul-1] +1;


                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 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())
    {
        ASSIMP_LOG_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())
            {
                ASSIMP_LOG_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& curMesh = meshes[(*it).first];
            Face &face = curMesh.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] >= curMesh.verts.size())
                {
                    ASSIMP_LOG_WARN("Quick3D: Vertex index overflow");
                    face.indices[n] = 0;
                }

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

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

                // copy texture coordinates
                if (uv && curMesh.uv.size())
                {
                    if (curMesh.prevUVIdx != 0xffffffff && curMesh.uv.size() >= curMesh.verts.size()) // workaround
                    {
                        *uv = curMesh.uv[face.indices[n]];
                    }
                    else
                    {
                        if (face.uvindices[n] >= curMesh.uv.size())
                        {
                            ASSIMP_LOG_WARN("Quick3D: Texture coordinate index overflow");
                            face.uvindices[n] = 0;
                        }
                        *uv = curMesh.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
