#include<iostream>
#include<fstream>
#include<vector>
#include<string>
using namespace std;


struct Header {
    //Structure for header on skl files
    char fileType[8];
    int numObjects;
    int skeletonHash;
    int numElements;
};

struct Bone {
    //Structure for a bone in skl files
    char name[32];
    int parent;
    float scale;
    float matrix[3][4];
};

struct SkinModelHeader {
    //Structure for the Header in skn files
    int magic;
    short numMaterials;
    short numObjects;
};
struct SkinModelMaterial {
    //Structure for a material block in skn files
    int matIndex;
    char name[64];
    int startVertex;
    int numVertices;
    int startIndex;
    int numIndices;
};
struct SkinModelVertex {
    //Vertex block in skn files
    float position[3];
    char  boneIndex[4];
    float weights[4];
    float normal[3];
    float texcoords[2];
};
struct SkinModelData {
    //data block in skn files
    int numIndices;
    int numVertices;
    vector<short> indices;
    vector<SkinModelVertex> verteces;
};

struct SkinModel {
    //Skin model data structure
    SkinModelHeader header;
    vector<SkinModelMaterial> materials;
    SkinModelData modelData;

    void importSkn(string infile) {
        //import from .skn file
        ifstream fin;
        fin.open(infile.c_str(), ios::binary);
        if (fin.fail()) {
            cout << "ERROR: could not open " << infile << endl;
            exit(1);
        }
        fin.read((char*)(void*)&header,sizeof(SkinModelHeader));
        if (header.magic != 1122867) {
            cout << "ERROR: " << infile << " is not a valid skn file" << endl;
            exit(1);
        }
        //for (int i = 0; i < header.numMaterials; i++) {
        if (header.numMaterials) {
            SkinModelMaterial mat;
            fin.read((char*)(void*)&mat, sizeof(SkinModelMaterial));
            materials.push_back(mat);
        }

        fin.read((char*)(void*)&modelData.numIndices,4);
        fin.read((char*)(void*)&modelData.numVertices,4);

        for (int i = 0; i < modelData.numIndices; i++) {
            short idx;
            fin.read((char*)(void*)&idx, 2);
            modelData.indices.push_back(idx);
        }
        for (int i = 0; i < modelData.numVertices; i++) {
            SkinModelVertex vtx;
            fin.read((char*)(void*)&vtx,sizeof(SkinModelVertex));
            modelData.verteces.push_back(vtx);
        }
    }
};
struct AnimationHeader {
    char filetype[8];
    int three;
    int magic;
    int numBones;
    int numFrames;
    int fps;
};
struct AnimationFrame {
    float quat[4];
    float position[3];
};
struct AnimationBone {
    char boneName[32];
    int boneID;
};
void quat2mat(const float* quat, float mat[3][4]) {
    float X = quat[0];
    float Y = quat[1];
    float Z = quat[2];
    float W = quat[3];

    float xx      = X * X;
    float xy      = X * Y;
    float xz      = X * Z;
    float xw      = X * W;
    float yy      = Y * Y;
    float yz      = Y * Z;
    float yw      = Y * W;
    float zz      = Z * Z;
    float zw      = Z * W;

    mat[0][0] = 1 - 2 * ( yy + zz );
    mat[0][1] =     2 * ( xy - zw );
    mat[0][2] =     2 * ( xz + yw );

    mat[1][0] =     2 * ( xy + zw );
    mat[1][1] = 1 - 2 * ( xx + zz );
    mat[1][2] =     2 * ( yz - xw );

    mat[2][0] =     2 * ( xz - yw );
    mat[2][1] =     2 * ( yz + xw );
    mat[2][2] = 1 - 2 * ( xx + yy );

    mat[0][3]  = mat[1][3] = mat[2][3] = 0;
}
struct IniBinHeader {
    int one;
    int numEntries;
    int stringsSize;
};
struct IniBinEntry {
    unsigned int varID;
    int offset;
};

int main(int argc, char *argv[])
{
    if(argc<5) exit(5);
    string cmd = string(argv[1]);
    string type = string(argv[2]);
    string inputFile = string(argv[3]);
    string outputFile = string(argv[4]);

     if (cmd == "decompile" || cmd == "d") {
        if (type == "skn" || type == "skin") {
            cout << "Decompiling binary .skn file: " << inputFile << " to .obj file: " << outputFile << endl;
            SkinModel model;
            model.importSkn(inputFile);
            model.exportObj(outputFile);
            cout << "Done!" << endl;
}

    return 0;
}