#ifndef _DATA_GENERATOR
#define _DATA_GENERATOR


#include <iostream>
#include <math.h>
#include <stdlib.h>
#include <vector>


using namespace std;



/*
  Data generator for different families of distributions
*/


unsigned int generate_uniform(unsigned int sizedom, double totalmass, vector<unsigned int> &f)
{
  unsigned int tuples_no = 0;

  totalmass = (sizedom > totalmass) ? sizedom : totalmass;

  for (unsigned int i = 0; i < sizedom; i++)
  {
    f[i] = (unsigned int)rint(totalmass / sizedom);
    tuples_no += f[i];
  }

  return tuples_no;
}


unsigned int generate_uniform_limited(unsigned int sizedom, double totalmass, double cutoff, vector<unsigned int> &f)
{
  unsigned int tuples_no = 0;

  unsigned int new_domain = (unsigned int)rint(sizedom * cutoff);
  totalmass = (new_domain > totalmass) ? new_domain : totalmass;

  for (unsigned int i = 0; i < sizedom; i++)
    f[i] = 0;

  for (unsigned int i = 0; i < new_domain; i++)
  {
    f[i] = (unsigned int)rint(totalmass / new_domain);
    tuples_no += f[i];
  }

  return tuples_no;
}


unsigned int generate_zipf(unsigned int sizedom, double totalmass, double zipf_param, vector<unsigned int> &f)
{
  if (zipf_param == 0.0)
  {
    return generate_uniform(sizedom, totalmass, f);
  }

  unsigned int tuples_no = 0;

  // compute the normalization coefficient
  double normcoef = 0.0;
  for (unsigned int i = 0; i < sizedom; i++)
    normcoef += 1 / pow(i + 1, zipf_param);

  // put the frequency table in f
  for (unsigned int i = 0; i < sizedom; i++)
  {
    f[i] = (unsigned int)rint(totalmass / (pow(i + 1, zipf_param) * normcoef));
    tuples_no += f[i];
  }

  return tuples_no;
}


unsigned int generate_zipf_right(unsigned int sizedom, double totalmass, double zipf_param, double right_t, vector<unsigned int> &f)
{
  if (zipf_param == 0.0)
  {
    return generate_uniform(sizedom, totalmass, f);
  }

  unsigned int tuples_no = 0;

  // compute the normalization coefficient
  double normcoef = 0.0;
  for (unsigned int i = 0; i < sizedom; i++)
    normcoef += 1 / pow(i + 1, zipf_param);

  // put the frequency table in f
  for (unsigned int i = 0; i < sizedom; i++)
  {
    f[i] = (unsigned int)rint(totalmass / (pow(i + 1, zipf_param) * normcoef));
    tuples_no += f[i];
  }

  unsigned int right_m = (unsigned int)rint(right_t);
  unsigned int *t_f = new unsigned int [sizedom];
  for (unsigned int i = 0; i < sizedom; i++)
    t_f[i] = f[i];

  for (unsigned int i = 0; i < sizedom; i++)
    f[(i + right_m) % sizedom] = t_f[i];

  delete [] t_f;

  return tuples_no;
}


unsigned int generate_reversed_zipf(unsigned int sizedom, double totalmass, double zipf_param, vector<unsigned int> &f)
{
  unsigned int tuples_no = 0;

  // compute the normalization coefficient
  double normcoef = 0.0;
  for (unsigned int i = 0; i < sizedom; i++)
    normcoef += 1 / pow(i + 1, zipf_param);

  // put the frequency table in f
  for (unsigned int i = 0; i < sizedom; i++)
  {
    f[i] = (unsigned int)rint(totalmass / (pow(sizedom - i, zipf_param) * normcoef));
    tuples_no += f[i];
  }

  return tuples_no;
}



void random_shuffling(vector<unsigned int> &f)
{
  unsigned int sizedom = f.size();

  for (unsigned int i = 0; i < sizedom; i++)
  {
    unsigned int ip = rand() % sizedom;
    unsigned int tmp = f[i];
    f[i] = f[ip];
    f[ip] = tmp;
  }
}


void random_shuffling(vector<unsigned int> &f, vector<unsigned int> &g)
{
  unsigned int sizedom = f.size();

  for (unsigned int i = 0; i < sizedom; i++)
  {
    unsigned int ip = rand() % sizedom;
    unsigned int tmp = f[i];
    f[i] = f[ip];
    f[ip] = tmp;

    tmp = g[i];
    g[i] = g[ip];
    g[ip] = tmp;
  }
}


void decorelate(vector<unsigned int> &f, double p_decor)
{
  unsigned int sizedom = f.size();

  if (p_decor < 0)
  {
    for (int i = 0 ; i < (sizedom/2); i++)
    {
      int temp = f[sizedom - 1 - i];
      f[sizedom - 1 - i] = f[i];
      f[i] = temp;
    }
  }

  for(int i = 0 ; i < sizedom * (1.0 - fabs(p_decor)); i++)
  {
    int ind1, ind2;
    ind1 = int(sizedom * drand48());
    ind2 = int(sizedom * drand48());

    int temp = f[ind2];
    f[ind2] = f[ind1];
    f[ind1] = temp;
  }
}


void print_freq_table(vector<unsigned int> &f)
{
  for (unsigned int i = 0; i < f.size(); i++)
    cout << i << "\t" << f[i] << endl;
}

#endif