/* Class for treating spins for all the possible configuration (for FIXED composition).

   Written by k-fleak 

*/


#pragma warning(disable:4786)

#include<iostream>
#include<vector>
#include<iterator>
#include<math.h>
#include<map>

#ifndef __SPINBANK_CPP
#define __SPINBANK_CPP


class SpinBank{
private:
  int Nconf;
  std::vector<int> configNow, configOld, configInit;
  std::vector<int> spinArray;
  void setInitialConfiguration(std::vector<int> &NatomArray);
  void printData(std::vector<std::pair<int, int> > inputs);
  static int Nflip;

public:
  SpinBank(std::vector<int> &spinArrayIn, std::vector<int> &NatomArray);
  ~SpinBank();
  int getNconf();
  int getNflip();
  std::vector<std::pair<int, int> > getNextSpin();
  std::vector<std::pair<int, int> > getInitialSpin();
};


int SpinBank::Nflip = 0;


SpinBank::SpinBank(std::vector<int> &spinArrayIn, std::vector<int> &NatomArray){
  setInitialConfiguration(NatomArray);
  for (int i = 0; i < spinArrayIn.size() ; ++i){
    spinArray.push_back(spinArrayIn[i]);
  }
}


SpinBank::~SpinBank(){}


inline int SpinBank::getNconf(){
  return Nconf;
}


inline int SpinBank::getNflip(){
  return Nflip;
}


std::vector<std::pair<int, int> > SpinBank::getInitialSpin(){
  std::vector<std::pair<int, int> > initSpinArray;
  int stmp;
  for ( int i = 0; i < configInit.size() ; ++i){
    if (configInit[i] != 0){
      stmp = spinArray[configInit[i]];
      initSpinArray.push_back(std::pair<int,int>(i, stmp ));
    }
  }
  return initSpinArray;
}


void SpinBank::setInitialConfiguration(std::vector<int> &NatomArray){
  int conf = 0;
  int ntmp = 0;
  Nconf = 0;  
  for (int i = 0; i < NatomArray.size(); ++i){
    ntmp = NatomArray[i];
    for (int j = 0; j < ntmp; ++j){
      configNow.push_back(conf);
    }
    ++conf;
  }
  sort(configNow.begin(), configNow.end());

  /// Estimate num of config ///
  while (next_permutation(configNow.begin(), configNow.end())){
    Nconf += 1;
  }
  sort(configNow.begin(), configNow.end());

  for (int i = 0; i < configNow.size(); ++i){
    configInit.push_back(configNow[i]);
  }
}


std::vector<std::pair<int, int> > SpinBank::getNextSpin(){
  std::vector<std::pair<int, int> > nextSpinArray;
  int stmp;

  configOld.clear();
  for (int i = 0; i < configNow.size(); ++i){
    configOld.push_back(configNow[i]);
  }

  next_permutation(configNow.begin(), configNow.end());
  
  for (int i = 0; i < configNow.size(); ++i){
    if (configNow[i] != configOld[i]){
      stmp = spinArray[configNow[i]];
      nextSpinArray.push_back(std::pair<int,int>(i, stmp));
      Nflip += 1;
    }
  }
  return nextSpinArray;
}

void SpinBank::printData(std::vector<std::pair<int, int> > inputs){
  std::vector<std::pair<int, int> >::iterator its;
  its = inputs.begin();
  while (its != inputs.end()){
    std::cout << (*its).first << "  " << (*its).second << std::endl;
    ++its;
  }
}



#endif