/*

 * filestorage_sample demonstrate the usage of the opencv serialization functionality

 */

#include "opencv2/core/core.hpp"

#include <iostream>

#include <string>

using std::string;

using std::cout;

using std::endl;

using std::cerr;

using std::ostream;

using namespace cv;

static void help(char** av)

{

  cout << "\nfilestorage_sample demonstrate the usage of the opencv serialization functionality.\n"

      << "usage:\n"

      <<  av[0] << " outputfile.yml.gz\n"

      << "\n   outputfile above can have many different extenstions, see below."

      << "\nThis program demonstrates the use of FileStorage for serialization, that is use << and >>  in OpenCV\n"

      << "For example, how to create a class and have it serialize, but also how to use it to read and write matrices.\n"

      << "FileStorage allows you to serialize to various formats specified by the file end type."

          << "\nYou should try using different file extensions.(e.g. yaml yml xml xml.gz yaml.gz etc...)\n" << endl;

}

struct MyData

{

  MyData() :

    A(0), X(0), id()

  {

  }

  explicit MyData(int) :

    A(97), X(CV_PI), id("mydata1234")

  {

  }

  int A;

  double X;

  string id;

  void write(FileStorage& fs) const //Write serialization for this class

  {

    fs << "{" << "A" << A << "X" << X << "id" << id << "}";

  }

  void read(const FileNode& node)  //Read serialization for this class

  {

    A = (int)node["A"];

    X = (double)node["X"];

    id = (string)node["id"];

  }

};

//These write and read functions must exist as per the inline functions in operations.hpp

static void write(FileStorage& fs, const std::string&, const MyData& x){

  x.write(fs);

}

static void read(const FileNode& node, MyData& x, const MyData& default_value = MyData()){

  if(node.empty())

    x = default_value;

  else

    x.read(node);

}

static ostream& operator<<(ostream& out, const MyData& m){

  out << "{ id = " << m.id << ", ";

  out << "X = " << m.X << ", ";

  out << "A = " << m.A << "}";

  return out;

}

int main(int ac, char** av)

{

  if (ac != 2)

  {

    help(av);

    return 1;

  }

  string filename = av[1];

  //write

  {

    FileStorage fs(filename, FileStorage::WRITE);

    cout << "writing images\n";

    fs << "images" << "[";

    fs << "image1.jpg" << "myfi.png" << "baboon.jpg";

    cout << "image1.jpg" << " myfi.png" << " baboon.jpg" << endl;

    fs << "]";

    cout << "writing mats\n";

    Mat R =Mat_<double>::eye(3, 3),T = Mat_<double>::zeros(3, 1);

    cout << "R = " << R << "\n";

    cout << "T = " << T << "\n";

    fs << "R" << R;

    fs << "T" << T;

    cout << "writing MyData struct\n";

    MyData m(1);

    fs << "mdata" << m;

    cout << m << endl;

    cout << "writing vector of int\n";

    std::vector<int> intvec(3);

    intvec[0] = 6;

    intvec[1] = 12;

    intvec[2] = 22;

    fs << "int_vec" << intvec;

    cout << "writing vector of string\n";

    std::vector<string> strvec(3);

    strvec[0] = "str1";

    strvec[1] = string("[with brackets]");

    strvec[2] = string("\"with quotes\"");

    fs << "str_vec" << strvec;

    cout << "writing vector of MyData struct \n";

    std::vector<MyData> mvec(3, m);

    fs << "mdata_vec" << mvec;

  }

  //read

  {

    FileStorage fs(filename, FileStorage::READ);

    if (!fs.isOpened())

    {

      cerr << "failed to open " << filename << endl;

      help(av);

      return 1;

    }

    FileNode n = fs["images"];

    if (n.type() != FileNode::SEQ)

    {

      cerr << "images is not a sequence! FAIL" << endl;

      return 1;

    }

    cout << "reading images\n";

    FileNodeIterator it = n.begin(), it_end = n.end();

    for (; it != it_end; ++it)

    {

      cout << (string)*it << "\n";

    }

    Mat R, T;

    cout << "reading R and T" << endl;

    fs["R"] >> R;

    fs["T"] >> T;

    cout << "R = " << R << "\n";

    cout << "T = " << T << endl;

    MyData m;

    fs["mdata"] >> m;

    cout << "read mdata\n";

    cout << m << endl;

    cout << "attempting to read mdata_b\n";   //Show default behavior for empty matrix

    fs["mdata_b"] >> m;

    cout << "read mdata_b\n";

    cout << m << endl;

  }

  cout << "Try opening " << filename << " to see the serialized data." << endl << endl;

  //read from string

  {

    cout << "Read data from string\n";

    string dataString =

        "%YAML:1.0\n"

        "mdata:\n"

        "   A: 97\n"

        "   X: 3.1415926535897931e+00\n"

        "   id: mydata1234\n";

    MyData m;

    FileStorage fs(dataString, FileStorage::READ | FileStorage::MEMORY);

    cout << "attempting to read mdata_b from string\n";   //Show default behavior for empty matrix

    fs["mdata"] >> m;

    cout << "read mdata\n";

    cout << m << endl;

  }

  //write to string

  {

    cout << "Write data to string\n";

    FileStorage fs(filename, FileStorage::WRITE | FileStorage::MEMORY | FileStorage::FORMAT_YAML);

    cout << "writing MyData struct\n";

    MyData m(1);

    fs << "mdata" << m;

    cout << m << endl;

    string createdString = fs.releaseAndGetString();

    cout << "Created string:\n" << createdString << "\n";

  }

  return 0;

}